xref: /openbmc/linux/fs/ext4/super.c (revision f9834f18)
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 
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, const char *func,
339 			    unsigned int line)
340 {
341 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
342 
343 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
344 	if (bdev_read_only(sb->s_bdev))
345 		return;
346 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
347 	ext4_update_tstamp(es, s_last_error_time);
348 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
349 	es->s_last_error_line = cpu_to_le32(line);
350 	if (es->s_last_error_errcode == 0)
351 		es->s_last_error_errcode = EXT4_ERR_EFSCORRUPTED;
352 	if (!es->s_first_error_time) {
353 		es->s_first_error_time = es->s_last_error_time;
354 		es->s_first_error_time_hi = es->s_last_error_time_hi;
355 		strncpy(es->s_first_error_func, func,
356 			sizeof(es->s_first_error_func));
357 		es->s_first_error_line = cpu_to_le32(line);
358 		es->s_first_error_ino = es->s_last_error_ino;
359 		es->s_first_error_block = es->s_last_error_block;
360 		es->s_first_error_errcode = es->s_last_error_errcode;
361 	}
362 	/*
363 	 * Start the daily error reporting function if it hasn't been
364 	 * started already
365 	 */
366 	if (!es->s_error_count)
367 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
368 	le32_add_cpu(&es->s_error_count, 1);
369 }
370 
371 static void save_error_info(struct super_block *sb, const char *func,
372 			    unsigned int line)
373 {
374 	__save_error_info(sb, func, line);
375 	ext4_commit_super(sb, 1);
376 }
377 
378 /*
379  * The del_gendisk() function uninitializes the disk-specific data
380  * structures, including the bdi structure, without telling anyone
381  * else.  Once this happens, any attempt to call mark_buffer_dirty()
382  * (for example, by ext4_commit_super), will cause a kernel OOPS.
383  * This is a kludge to prevent these oops until we can put in a proper
384  * hook in del_gendisk() to inform the VFS and file system layers.
385  */
386 static int block_device_ejected(struct super_block *sb)
387 {
388 	struct inode *bd_inode = sb->s_bdev->bd_inode;
389 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
390 
391 	return bdi->dev == NULL;
392 }
393 
394 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
395 {
396 	struct super_block		*sb = journal->j_private;
397 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
398 	int				error = is_journal_aborted(journal);
399 	struct ext4_journal_cb_entry	*jce;
400 
401 	BUG_ON(txn->t_state == T_FINISHED);
402 
403 	ext4_process_freed_data(sb, txn->t_tid);
404 
405 	spin_lock(&sbi->s_md_lock);
406 	while (!list_empty(&txn->t_private_list)) {
407 		jce = list_entry(txn->t_private_list.next,
408 				 struct ext4_journal_cb_entry, jce_list);
409 		list_del_init(&jce->jce_list);
410 		spin_unlock(&sbi->s_md_lock);
411 		jce->jce_func(sb, jce, error);
412 		spin_lock(&sbi->s_md_lock);
413 	}
414 	spin_unlock(&sbi->s_md_lock);
415 }
416 
417 static bool system_going_down(void)
418 {
419 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
420 		|| system_state == SYSTEM_RESTART;
421 }
422 
423 /* Deal with the reporting of failure conditions on a filesystem such as
424  * inconsistencies detected or read IO failures.
425  *
426  * On ext2, we can store the error state of the filesystem in the
427  * superblock.  That is not possible on ext4, because we may have other
428  * write ordering constraints on the superblock which prevent us from
429  * writing it out straight away; and given that the journal is about to
430  * be aborted, we can't rely on the current, or future, transactions to
431  * write out the superblock safely.
432  *
433  * We'll just use the jbd2_journal_abort() error code to record an error in
434  * the journal instead.  On recovery, the journal will complain about
435  * that error until we've noted it down and cleared it.
436  */
437 
438 static void ext4_handle_error(struct super_block *sb)
439 {
440 	if (test_opt(sb, WARN_ON_ERROR))
441 		WARN_ON_ONCE(1);
442 
443 	if (sb_rdonly(sb))
444 		return;
445 
446 	if (!test_opt(sb, ERRORS_CONT)) {
447 		journal_t *journal = EXT4_SB(sb)->s_journal;
448 
449 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
450 		if (journal)
451 			jbd2_journal_abort(journal, -EIO);
452 	}
453 	/*
454 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
455 	 * could panic during 'reboot -f' as the underlying device got already
456 	 * disabled.
457 	 */
458 	if (test_opt(sb, ERRORS_RO) || system_going_down()) {
459 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
460 		/*
461 		 * Make sure updated value of ->s_mount_flags will be visible
462 		 * before ->s_flags update
463 		 */
464 		smp_wmb();
465 		sb->s_flags |= SB_RDONLY;
466 	} else if (test_opt(sb, ERRORS_PANIC)) {
467 		if (EXT4_SB(sb)->s_journal &&
468 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
469 			return;
470 		panic("EXT4-fs (device %s): panic forced after error\n",
471 			sb->s_id);
472 	}
473 }
474 
475 #define ext4_error_ratelimit(sb)					\
476 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
477 			     "EXT4-fs error")
478 
479 void __ext4_error(struct super_block *sb, const char *function,
480 		  unsigned int line, const char *fmt, ...)
481 {
482 	struct va_format vaf;
483 	va_list args;
484 
485 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
486 		return;
487 
488 	trace_ext4_error(sb, function, line);
489 	if (ext4_error_ratelimit(sb)) {
490 		va_start(args, fmt);
491 		vaf.fmt = fmt;
492 		vaf.va = &args;
493 		printk(KERN_CRIT
494 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
495 		       sb->s_id, function, line, current->comm, &vaf);
496 		va_end(args);
497 	}
498 	save_error_info(sb, function, line);
499 	ext4_handle_error(sb);
500 }
501 
502 void __ext4_error_inode(struct inode *inode, const char *function,
503 			unsigned int line, ext4_fsblk_t block,
504 			const char *fmt, ...)
505 {
506 	va_list args;
507 	struct va_format vaf;
508 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
509 
510 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
511 		return;
512 
513 	trace_ext4_error(inode->i_sb, function, line);
514 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
515 	es->s_last_error_block = cpu_to_le64(block);
516 	if (ext4_error_ratelimit(inode->i_sb)) {
517 		va_start(args, fmt);
518 		vaf.fmt = fmt;
519 		vaf.va = &args;
520 		if (block)
521 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
522 			       "inode #%lu: block %llu: comm %s: %pV\n",
523 			       inode->i_sb->s_id, function, line, inode->i_ino,
524 			       block, current->comm, &vaf);
525 		else
526 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
527 			       "inode #%lu: comm %s: %pV\n",
528 			       inode->i_sb->s_id, function, line, inode->i_ino,
529 			       current->comm, &vaf);
530 		va_end(args);
531 	}
532 	save_error_info(inode->i_sb, function, line);
533 	ext4_handle_error(inode->i_sb);
534 }
535 
536 void __ext4_error_file(struct file *file, const char *function,
537 		       unsigned int line, ext4_fsblk_t block,
538 		       const char *fmt, ...)
539 {
540 	va_list args;
541 	struct va_format vaf;
542 	struct ext4_super_block *es;
543 	struct inode *inode = file_inode(file);
544 	char pathname[80], *path;
545 
546 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
547 		return;
548 
549 	trace_ext4_error(inode->i_sb, function, line);
550 	es = EXT4_SB(inode->i_sb)->s_es;
551 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
552 	if (ext4_error_ratelimit(inode->i_sb)) {
553 		path = file_path(file, pathname, sizeof(pathname));
554 		if (IS_ERR(path))
555 			path = "(unknown)";
556 		va_start(args, fmt);
557 		vaf.fmt = fmt;
558 		vaf.va = &args;
559 		if (block)
560 			printk(KERN_CRIT
561 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
562 			       "block %llu: comm %s: path %s: %pV\n",
563 			       inode->i_sb->s_id, function, line, inode->i_ino,
564 			       block, current->comm, path, &vaf);
565 		else
566 			printk(KERN_CRIT
567 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
568 			       "comm %s: path %s: %pV\n",
569 			       inode->i_sb->s_id, function, line, inode->i_ino,
570 			       current->comm, path, &vaf);
571 		va_end(args);
572 	}
573 	save_error_info(inode->i_sb, function, line);
574 	ext4_handle_error(inode->i_sb);
575 }
576 
577 const char *ext4_decode_error(struct super_block *sb, int errno,
578 			      char nbuf[16])
579 {
580 	char *errstr = NULL;
581 
582 	switch (errno) {
583 	case -EFSCORRUPTED:
584 		errstr = "Corrupt filesystem";
585 		break;
586 	case -EFSBADCRC:
587 		errstr = "Filesystem failed CRC";
588 		break;
589 	case -EIO:
590 		errstr = "IO failure";
591 		break;
592 	case -ENOMEM:
593 		errstr = "Out of memory";
594 		break;
595 	case -EROFS:
596 		if (!sb || (EXT4_SB(sb)->s_journal &&
597 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
598 			errstr = "Journal has aborted";
599 		else
600 			errstr = "Readonly filesystem";
601 		break;
602 	default:
603 		/* If the caller passed in an extra buffer for unknown
604 		 * errors, textualise them now.  Else we just return
605 		 * NULL. */
606 		if (nbuf) {
607 			/* Check for truncated error codes... */
608 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
609 				errstr = nbuf;
610 		}
611 		break;
612 	}
613 
614 	return errstr;
615 }
616 
617 void ext4_set_errno(struct super_block *sb, int err)
618 {
619 	if (err < 0)
620 		err = -err;
621 
622 	switch (err) {
623 	case EIO:
624 		err = EXT4_ERR_EIO;
625 		break;
626 	case ENOMEM:
627 		err = EXT4_ERR_ENOMEM;
628 		break;
629 	case EFSBADCRC:
630 		err = EXT4_ERR_EFSBADCRC;
631 		break;
632 	case EFSCORRUPTED:
633 		err = EXT4_ERR_EFSCORRUPTED;
634 		break;
635 	case ENOSPC:
636 		err = EXT4_ERR_ENOSPC;
637 		break;
638 	case ENOKEY:
639 		err = EXT4_ERR_ENOKEY;
640 		break;
641 	case EROFS:
642 		err = EXT4_ERR_EROFS;
643 		break;
644 	case EFBIG:
645 		err = EXT4_ERR_EFBIG;
646 		break;
647 	case EEXIST:
648 		err = EXT4_ERR_EEXIST;
649 		break;
650 	case ERANGE:
651 		err = EXT4_ERR_ERANGE;
652 		break;
653 	case EOVERFLOW:
654 		err = EXT4_ERR_EOVERFLOW;
655 		break;
656 	case EBUSY:
657 		err = EXT4_ERR_EBUSY;
658 		break;
659 	case ENOTDIR:
660 		err = EXT4_ERR_ENOTDIR;
661 		break;
662 	case ENOTEMPTY:
663 		err = EXT4_ERR_ENOTEMPTY;
664 		break;
665 	case ESHUTDOWN:
666 		err = EXT4_ERR_ESHUTDOWN;
667 		break;
668 	case EFAULT:
669 		err = EXT4_ERR_EFAULT;
670 		break;
671 	default:
672 		err = EXT4_ERR_UNKNOWN;
673 	}
674 	EXT4_SB(sb)->s_es->s_last_error_errcode = err;
675 }
676 
677 /* __ext4_std_error decodes expected errors from journaling functions
678  * automatically and invokes the appropriate error response.  */
679 
680 void __ext4_std_error(struct super_block *sb, const char *function,
681 		      unsigned int line, int errno)
682 {
683 	char nbuf[16];
684 	const char *errstr;
685 
686 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
687 		return;
688 
689 	/* Special case: if the error is EROFS, and we're not already
690 	 * inside a transaction, then there's really no point in logging
691 	 * an error. */
692 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
693 		return;
694 
695 	if (ext4_error_ratelimit(sb)) {
696 		errstr = ext4_decode_error(sb, errno, nbuf);
697 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
698 		       sb->s_id, function, line, errstr);
699 	}
700 
701 	ext4_set_errno(sb, -errno);
702 	save_error_info(sb, function, line);
703 	ext4_handle_error(sb);
704 }
705 
706 /*
707  * ext4_abort is a much stronger failure handler than ext4_error.  The
708  * abort function may be used to deal with unrecoverable failures such
709  * as journal IO errors or ENOMEM at a critical moment in log management.
710  *
711  * We unconditionally force the filesystem into an ABORT|READONLY state,
712  * unless the error response on the fs has been set to panic in which
713  * case we take the easy way out and panic immediately.
714  */
715 
716 void __ext4_abort(struct super_block *sb, const char *function,
717 		unsigned int line, const char *fmt, ...)
718 {
719 	struct va_format vaf;
720 	va_list args;
721 
722 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
723 		return;
724 
725 	save_error_info(sb, function, line);
726 	va_start(args, fmt);
727 	vaf.fmt = fmt;
728 	vaf.va = &args;
729 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
730 	       sb->s_id, function, line, &vaf);
731 	va_end(args);
732 
733 	if (sb_rdonly(sb) == 0) {
734 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
735 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
736 		/*
737 		 * Make sure updated value of ->s_mount_flags will be visible
738 		 * before ->s_flags update
739 		 */
740 		smp_wmb();
741 		sb->s_flags |= SB_RDONLY;
742 		if (EXT4_SB(sb)->s_journal)
743 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
744 		save_error_info(sb, function, line);
745 	}
746 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
747 		if (EXT4_SB(sb)->s_journal &&
748 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
749 			return;
750 		panic("EXT4-fs panic from previous error\n");
751 	}
752 }
753 
754 void __ext4_msg(struct super_block *sb,
755 		const char *prefix, const char *fmt, ...)
756 {
757 	struct va_format vaf;
758 	va_list args;
759 
760 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
761 		return;
762 
763 	va_start(args, fmt);
764 	vaf.fmt = fmt;
765 	vaf.va = &args;
766 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
767 	va_end(args);
768 }
769 
770 #define ext4_warning_ratelimit(sb)					\
771 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
772 			     "EXT4-fs warning")
773 
774 void __ext4_warning(struct super_block *sb, const char *function,
775 		    unsigned int line, const char *fmt, ...)
776 {
777 	struct va_format vaf;
778 	va_list args;
779 
780 	if (!ext4_warning_ratelimit(sb))
781 		return;
782 
783 	va_start(args, fmt);
784 	vaf.fmt = fmt;
785 	vaf.va = &args;
786 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
787 	       sb->s_id, function, line, &vaf);
788 	va_end(args);
789 }
790 
791 void __ext4_warning_inode(const struct inode *inode, const char *function,
792 			  unsigned int line, const char *fmt, ...)
793 {
794 	struct va_format vaf;
795 	va_list args;
796 
797 	if (!ext4_warning_ratelimit(inode->i_sb))
798 		return;
799 
800 	va_start(args, fmt);
801 	vaf.fmt = fmt;
802 	vaf.va = &args;
803 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
804 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
805 	       function, line, inode->i_ino, current->comm, &vaf);
806 	va_end(args);
807 }
808 
809 void __ext4_grp_locked_error(const char *function, unsigned int line,
810 			     struct super_block *sb, ext4_group_t grp,
811 			     unsigned long ino, ext4_fsblk_t block,
812 			     const char *fmt, ...)
813 __releases(bitlock)
814 __acquires(bitlock)
815 {
816 	struct va_format vaf;
817 	va_list args;
818 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
819 
820 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
821 		return;
822 
823 	trace_ext4_error(sb, function, line);
824 	es->s_last_error_ino = cpu_to_le32(ino);
825 	es->s_last_error_block = cpu_to_le64(block);
826 	__save_error_info(sb, function, line);
827 
828 	if (ext4_error_ratelimit(sb)) {
829 		va_start(args, fmt);
830 		vaf.fmt = fmt;
831 		vaf.va = &args;
832 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
833 		       sb->s_id, function, line, grp);
834 		if (ino)
835 			printk(KERN_CONT "inode %lu: ", ino);
836 		if (block)
837 			printk(KERN_CONT "block %llu:",
838 			       (unsigned long long) block);
839 		printk(KERN_CONT "%pV\n", &vaf);
840 		va_end(args);
841 	}
842 
843 	if (test_opt(sb, WARN_ON_ERROR))
844 		WARN_ON_ONCE(1);
845 
846 	if (test_opt(sb, ERRORS_CONT)) {
847 		ext4_commit_super(sb, 0);
848 		return;
849 	}
850 
851 	ext4_unlock_group(sb, grp);
852 	ext4_commit_super(sb, 1);
853 	ext4_handle_error(sb);
854 	/*
855 	 * We only get here in the ERRORS_RO case; relocking the group
856 	 * may be dangerous, but nothing bad will happen since the
857 	 * filesystem will have already been marked read/only and the
858 	 * journal has been aborted.  We return 1 as a hint to callers
859 	 * who might what to use the return value from
860 	 * ext4_grp_locked_error() to distinguish between the
861 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
862 	 * aggressively from the ext4 function in question, with a
863 	 * more appropriate error code.
864 	 */
865 	ext4_lock_group(sb, grp);
866 	return;
867 }
868 
869 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
870 				     ext4_group_t group,
871 				     unsigned int flags)
872 {
873 	struct ext4_sb_info *sbi = EXT4_SB(sb);
874 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
875 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
876 	int ret;
877 
878 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
879 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
880 					    &grp->bb_state);
881 		if (!ret)
882 			percpu_counter_sub(&sbi->s_freeclusters_counter,
883 					   grp->bb_free);
884 	}
885 
886 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
887 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
888 					    &grp->bb_state);
889 		if (!ret && gdp) {
890 			int count;
891 
892 			count = ext4_free_inodes_count(sb, gdp);
893 			percpu_counter_sub(&sbi->s_freeinodes_counter,
894 					   count);
895 		}
896 	}
897 }
898 
899 void ext4_update_dynamic_rev(struct super_block *sb)
900 {
901 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
902 
903 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
904 		return;
905 
906 	ext4_warning(sb,
907 		     "updating to rev %d because of new feature flag, "
908 		     "running e2fsck is recommended",
909 		     EXT4_DYNAMIC_REV);
910 
911 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
912 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
913 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
914 	/* leave es->s_feature_*compat flags alone */
915 	/* es->s_uuid will be set by e2fsck if empty */
916 
917 	/*
918 	 * The rest of the superblock fields should be zero, and if not it
919 	 * means they are likely already in use, so leave them alone.  We
920 	 * can leave it up to e2fsck to clean up any inconsistencies there.
921 	 */
922 }
923 
924 /*
925  * Open the external journal device
926  */
927 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
928 {
929 	struct block_device *bdev;
930 	char b[BDEVNAME_SIZE];
931 
932 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
933 	if (IS_ERR(bdev))
934 		goto fail;
935 	return bdev;
936 
937 fail:
938 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
939 			__bdevname(dev, b), PTR_ERR(bdev));
940 	return NULL;
941 }
942 
943 /*
944  * Release the journal device
945  */
946 static void ext4_blkdev_put(struct block_device *bdev)
947 {
948 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
949 }
950 
951 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
952 {
953 	struct block_device *bdev;
954 	bdev = sbi->journal_bdev;
955 	if (bdev) {
956 		ext4_blkdev_put(bdev);
957 		sbi->journal_bdev = NULL;
958 	}
959 }
960 
961 static inline struct inode *orphan_list_entry(struct list_head *l)
962 {
963 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
964 }
965 
966 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
967 {
968 	struct list_head *l;
969 
970 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
971 		 le32_to_cpu(sbi->s_es->s_last_orphan));
972 
973 	printk(KERN_ERR "sb_info orphan list:\n");
974 	list_for_each(l, &sbi->s_orphan) {
975 		struct inode *inode = orphan_list_entry(l);
976 		printk(KERN_ERR "  "
977 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
978 		       inode->i_sb->s_id, inode->i_ino, inode,
979 		       inode->i_mode, inode->i_nlink,
980 		       NEXT_ORPHAN(inode));
981 	}
982 }
983 
984 #ifdef CONFIG_QUOTA
985 static int ext4_quota_off(struct super_block *sb, int type);
986 
987 static inline void ext4_quota_off_umount(struct super_block *sb)
988 {
989 	int type;
990 
991 	/* Use our quota_off function to clear inode flags etc. */
992 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
993 		ext4_quota_off(sb, type);
994 }
995 
996 /*
997  * This is a helper function which is used in the mount/remount
998  * codepaths (which holds s_umount) to fetch the quota file name.
999  */
1000 static inline char *get_qf_name(struct super_block *sb,
1001 				struct ext4_sb_info *sbi,
1002 				int type)
1003 {
1004 	return rcu_dereference_protected(sbi->s_qf_names[type],
1005 					 lockdep_is_held(&sb->s_umount));
1006 }
1007 #else
1008 static inline void ext4_quota_off_umount(struct super_block *sb)
1009 {
1010 }
1011 #endif
1012 
1013 static void ext4_put_super(struct super_block *sb)
1014 {
1015 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1016 	struct ext4_super_block *es = sbi->s_es;
1017 	struct buffer_head **group_desc;
1018 	struct flex_groups **flex_groups;
1019 	int aborted = 0;
1020 	int i, err;
1021 
1022 	ext4_unregister_li_request(sb);
1023 	ext4_quota_off_umount(sb);
1024 
1025 	destroy_workqueue(sbi->rsv_conversion_wq);
1026 
1027 	if (sbi->s_journal) {
1028 		aborted = is_journal_aborted(sbi->s_journal);
1029 		err = jbd2_journal_destroy(sbi->s_journal);
1030 		sbi->s_journal = NULL;
1031 		if ((err < 0) && !aborted) {
1032 			ext4_set_errno(sb, -err);
1033 			ext4_abort(sb, "Couldn't clean up the journal");
1034 		}
1035 	}
1036 
1037 	ext4_unregister_sysfs(sb);
1038 	ext4_es_unregister_shrinker(sbi);
1039 	del_timer_sync(&sbi->s_err_report);
1040 	ext4_release_system_zone(sb);
1041 	ext4_mb_release(sb);
1042 	ext4_ext_release(sb);
1043 
1044 	if (!sb_rdonly(sb) && !aborted) {
1045 		ext4_clear_feature_journal_needs_recovery(sb);
1046 		es->s_state = cpu_to_le16(sbi->s_mount_state);
1047 	}
1048 	if (!sb_rdonly(sb))
1049 		ext4_commit_super(sb, 1);
1050 
1051 	rcu_read_lock();
1052 	group_desc = rcu_dereference(sbi->s_group_desc);
1053 	for (i = 0; i < sbi->s_gdb_count; i++)
1054 		brelse(group_desc[i]);
1055 	kvfree(group_desc);
1056 	flex_groups = rcu_dereference(sbi->s_flex_groups);
1057 	if (flex_groups) {
1058 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
1059 			kvfree(flex_groups[i]);
1060 		kvfree(flex_groups);
1061 	}
1062 	rcu_read_unlock();
1063 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1064 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1065 	percpu_counter_destroy(&sbi->s_dirs_counter);
1066 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1067 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
1068 #ifdef CONFIG_QUOTA
1069 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1070 		kfree(get_qf_name(sb, sbi, i));
1071 #endif
1072 
1073 	/* Debugging code just in case the in-memory inode orphan list
1074 	 * isn't empty.  The on-disk one can be non-empty if we've
1075 	 * detected an error and taken the fs readonly, but the
1076 	 * in-memory list had better be clean by this point. */
1077 	if (!list_empty(&sbi->s_orphan))
1078 		dump_orphan_list(sb, sbi);
1079 	J_ASSERT(list_empty(&sbi->s_orphan));
1080 
1081 	sync_blockdev(sb->s_bdev);
1082 	invalidate_bdev(sb->s_bdev);
1083 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1084 		/*
1085 		 * Invalidate the journal device's buffers.  We don't want them
1086 		 * floating about in memory - the physical journal device may
1087 		 * hotswapped, and it breaks the `ro-after' testing code.
1088 		 */
1089 		sync_blockdev(sbi->journal_bdev);
1090 		invalidate_bdev(sbi->journal_bdev);
1091 		ext4_blkdev_remove(sbi);
1092 	}
1093 
1094 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1095 	sbi->s_ea_inode_cache = NULL;
1096 
1097 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1098 	sbi->s_ea_block_cache = NULL;
1099 
1100 	if (sbi->s_mmp_tsk)
1101 		kthread_stop(sbi->s_mmp_tsk);
1102 	brelse(sbi->s_sbh);
1103 	sb->s_fs_info = NULL;
1104 	/*
1105 	 * Now that we are completely done shutting down the
1106 	 * superblock, we need to actually destroy the kobject.
1107 	 */
1108 	kobject_put(&sbi->s_kobj);
1109 	wait_for_completion(&sbi->s_kobj_unregister);
1110 	if (sbi->s_chksum_driver)
1111 		crypto_free_shash(sbi->s_chksum_driver);
1112 	kfree(sbi->s_blockgroup_lock);
1113 	fs_put_dax(sbi->s_daxdev);
1114 #ifdef CONFIG_UNICODE
1115 	utf8_unload(sbi->s_encoding);
1116 #endif
1117 	kfree(sbi);
1118 }
1119 
1120 static struct kmem_cache *ext4_inode_cachep;
1121 
1122 /*
1123  * Called inside transaction, so use GFP_NOFS
1124  */
1125 static struct inode *ext4_alloc_inode(struct super_block *sb)
1126 {
1127 	struct ext4_inode_info *ei;
1128 
1129 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1130 	if (!ei)
1131 		return NULL;
1132 
1133 	inode_set_iversion(&ei->vfs_inode, 1);
1134 	spin_lock_init(&ei->i_raw_lock);
1135 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1136 	spin_lock_init(&ei->i_prealloc_lock);
1137 	ext4_es_init_tree(&ei->i_es_tree);
1138 	rwlock_init(&ei->i_es_lock);
1139 	INIT_LIST_HEAD(&ei->i_es_list);
1140 	ei->i_es_all_nr = 0;
1141 	ei->i_es_shk_nr = 0;
1142 	ei->i_es_shrink_lblk = 0;
1143 	ei->i_reserved_data_blocks = 0;
1144 	spin_lock_init(&(ei->i_block_reservation_lock));
1145 	ext4_init_pending_tree(&ei->i_pending_tree);
1146 #ifdef CONFIG_QUOTA
1147 	ei->i_reserved_quota = 0;
1148 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1149 #endif
1150 	ei->jinode = NULL;
1151 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1152 	spin_lock_init(&ei->i_completed_io_lock);
1153 	ei->i_sync_tid = 0;
1154 	ei->i_datasync_tid = 0;
1155 	atomic_set(&ei->i_unwritten, 0);
1156 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1157 	return &ei->vfs_inode;
1158 }
1159 
1160 static int ext4_drop_inode(struct inode *inode)
1161 {
1162 	int drop = generic_drop_inode(inode);
1163 
1164 	if (!drop)
1165 		drop = fscrypt_drop_inode(inode);
1166 
1167 	trace_ext4_drop_inode(inode, drop);
1168 	return drop;
1169 }
1170 
1171 static void ext4_free_in_core_inode(struct inode *inode)
1172 {
1173 	fscrypt_free_inode(inode);
1174 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1175 }
1176 
1177 static void ext4_destroy_inode(struct inode *inode)
1178 {
1179 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1180 		ext4_msg(inode->i_sb, KERN_ERR,
1181 			 "Inode %lu (%p): orphan list check failed!",
1182 			 inode->i_ino, EXT4_I(inode));
1183 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1184 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1185 				true);
1186 		dump_stack();
1187 	}
1188 }
1189 
1190 static void init_once(void *foo)
1191 {
1192 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1193 
1194 	INIT_LIST_HEAD(&ei->i_orphan);
1195 	init_rwsem(&ei->xattr_sem);
1196 	init_rwsem(&ei->i_data_sem);
1197 	init_rwsem(&ei->i_mmap_sem);
1198 	inode_init_once(&ei->vfs_inode);
1199 }
1200 
1201 static int __init init_inodecache(void)
1202 {
1203 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1204 				sizeof(struct ext4_inode_info), 0,
1205 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1206 					SLAB_ACCOUNT),
1207 				offsetof(struct ext4_inode_info, i_data),
1208 				sizeof_field(struct ext4_inode_info, i_data),
1209 				init_once);
1210 	if (ext4_inode_cachep == NULL)
1211 		return -ENOMEM;
1212 	return 0;
1213 }
1214 
1215 static void destroy_inodecache(void)
1216 {
1217 	/*
1218 	 * Make sure all delayed rcu free inodes are flushed before we
1219 	 * destroy cache.
1220 	 */
1221 	rcu_barrier();
1222 	kmem_cache_destroy(ext4_inode_cachep);
1223 }
1224 
1225 void ext4_clear_inode(struct inode *inode)
1226 {
1227 	invalidate_inode_buffers(inode);
1228 	clear_inode(inode);
1229 	ext4_discard_preallocations(inode);
1230 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1231 	dquot_drop(inode);
1232 	if (EXT4_I(inode)->jinode) {
1233 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1234 					       EXT4_I(inode)->jinode);
1235 		jbd2_free_inode(EXT4_I(inode)->jinode);
1236 		EXT4_I(inode)->jinode = NULL;
1237 	}
1238 	fscrypt_put_encryption_info(inode);
1239 	fsverity_cleanup_inode(inode);
1240 }
1241 
1242 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1243 					u64 ino, u32 generation)
1244 {
1245 	struct inode *inode;
1246 
1247 	/*
1248 	 * Currently we don't know the generation for parent directory, so
1249 	 * a generation of 0 means "accept any"
1250 	 */
1251 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1252 	if (IS_ERR(inode))
1253 		return ERR_CAST(inode);
1254 	if (generation && inode->i_generation != generation) {
1255 		iput(inode);
1256 		return ERR_PTR(-ESTALE);
1257 	}
1258 
1259 	return inode;
1260 }
1261 
1262 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1263 					int fh_len, int fh_type)
1264 {
1265 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1266 				    ext4_nfs_get_inode);
1267 }
1268 
1269 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1270 					int fh_len, int fh_type)
1271 {
1272 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1273 				    ext4_nfs_get_inode);
1274 }
1275 
1276 static int ext4_nfs_commit_metadata(struct inode *inode)
1277 {
1278 	struct writeback_control wbc = {
1279 		.sync_mode = WB_SYNC_ALL
1280 	};
1281 
1282 	trace_ext4_nfs_commit_metadata(inode);
1283 	return ext4_write_inode(inode, &wbc);
1284 }
1285 
1286 /*
1287  * Try to release metadata pages (indirect blocks, directories) which are
1288  * mapped via the block device.  Since these pages could have journal heads
1289  * which would prevent try_to_free_buffers() from freeing them, we must use
1290  * jbd2 layer's try_to_free_buffers() function to release them.
1291  */
1292 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1293 				 gfp_t wait)
1294 {
1295 	journal_t *journal = EXT4_SB(sb)->s_journal;
1296 
1297 	WARN_ON(PageChecked(page));
1298 	if (!page_has_buffers(page))
1299 		return 0;
1300 	if (journal)
1301 		return jbd2_journal_try_to_free_buffers(journal, page,
1302 						wait & ~__GFP_DIRECT_RECLAIM);
1303 	return try_to_free_buffers(page);
1304 }
1305 
1306 #ifdef CONFIG_FS_ENCRYPTION
1307 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1308 {
1309 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1310 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1311 }
1312 
1313 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1314 							void *fs_data)
1315 {
1316 	handle_t *handle = fs_data;
1317 	int res, res2, credits, retries = 0;
1318 
1319 	/*
1320 	 * Encrypting the root directory is not allowed because e2fsck expects
1321 	 * lost+found to exist and be unencrypted, and encrypting the root
1322 	 * directory would imply encrypting the lost+found directory as well as
1323 	 * the filename "lost+found" itself.
1324 	 */
1325 	if (inode->i_ino == EXT4_ROOT_INO)
1326 		return -EPERM;
1327 
1328 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1329 		return -EINVAL;
1330 
1331 	res = ext4_convert_inline_data(inode);
1332 	if (res)
1333 		return res;
1334 
1335 	/*
1336 	 * If a journal handle was specified, then the encryption context is
1337 	 * being set on a new inode via inheritance and is part of a larger
1338 	 * transaction to create the inode.  Otherwise the encryption context is
1339 	 * being set on an existing inode in its own transaction.  Only in the
1340 	 * latter case should the "retry on ENOSPC" logic be used.
1341 	 */
1342 
1343 	if (handle) {
1344 		res = ext4_xattr_set_handle(handle, inode,
1345 					    EXT4_XATTR_INDEX_ENCRYPTION,
1346 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1347 					    ctx, len, 0);
1348 		if (!res) {
1349 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1350 			ext4_clear_inode_state(inode,
1351 					EXT4_STATE_MAY_INLINE_DATA);
1352 			/*
1353 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1354 			 * S_DAX may be disabled
1355 			 */
1356 			ext4_set_inode_flags(inode);
1357 		}
1358 		return res;
1359 	}
1360 
1361 	res = dquot_initialize(inode);
1362 	if (res)
1363 		return res;
1364 retry:
1365 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1366 				     &credits);
1367 	if (res)
1368 		return res;
1369 
1370 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1371 	if (IS_ERR(handle))
1372 		return PTR_ERR(handle);
1373 
1374 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1375 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1376 				    ctx, len, 0);
1377 	if (!res) {
1378 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1379 		/*
1380 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1381 		 * S_DAX may be disabled
1382 		 */
1383 		ext4_set_inode_flags(inode);
1384 		res = ext4_mark_inode_dirty(handle, inode);
1385 		if (res)
1386 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1387 	}
1388 	res2 = ext4_journal_stop(handle);
1389 
1390 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1391 		goto retry;
1392 	if (!res)
1393 		res = res2;
1394 	return res;
1395 }
1396 
1397 static bool ext4_dummy_context(struct inode *inode)
1398 {
1399 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1400 }
1401 
1402 static bool ext4_has_stable_inodes(struct super_block *sb)
1403 {
1404 	return ext4_has_feature_stable_inodes(sb);
1405 }
1406 
1407 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1408 				       int *ino_bits_ret, int *lblk_bits_ret)
1409 {
1410 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1411 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1412 }
1413 
1414 static const struct fscrypt_operations ext4_cryptops = {
1415 	.key_prefix		= "ext4:",
1416 	.get_context		= ext4_get_context,
1417 	.set_context		= ext4_set_context,
1418 	.dummy_context		= ext4_dummy_context,
1419 	.empty_dir		= ext4_empty_dir,
1420 	.max_namelen		= EXT4_NAME_LEN,
1421 	.has_stable_inodes	= ext4_has_stable_inodes,
1422 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1423 };
1424 #endif
1425 
1426 #ifdef CONFIG_QUOTA
1427 static const char * const quotatypes[] = INITQFNAMES;
1428 #define QTYPE2NAME(t) (quotatypes[t])
1429 
1430 static int ext4_write_dquot(struct dquot *dquot);
1431 static int ext4_acquire_dquot(struct dquot *dquot);
1432 static int ext4_release_dquot(struct dquot *dquot);
1433 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1434 static int ext4_write_info(struct super_block *sb, int type);
1435 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1436 			 const struct path *path);
1437 static int ext4_quota_on_mount(struct super_block *sb, int type);
1438 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1439 			       size_t len, loff_t off);
1440 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1441 				const char *data, size_t len, loff_t off);
1442 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1443 			     unsigned int flags);
1444 static int ext4_enable_quotas(struct super_block *sb);
1445 
1446 static struct dquot **ext4_get_dquots(struct inode *inode)
1447 {
1448 	return EXT4_I(inode)->i_dquot;
1449 }
1450 
1451 static const struct dquot_operations ext4_quota_operations = {
1452 	.get_reserved_space	= ext4_get_reserved_space,
1453 	.write_dquot		= ext4_write_dquot,
1454 	.acquire_dquot		= ext4_acquire_dquot,
1455 	.release_dquot		= ext4_release_dquot,
1456 	.mark_dirty		= ext4_mark_dquot_dirty,
1457 	.write_info		= ext4_write_info,
1458 	.alloc_dquot		= dquot_alloc,
1459 	.destroy_dquot		= dquot_destroy,
1460 	.get_projid		= ext4_get_projid,
1461 	.get_inode_usage	= ext4_get_inode_usage,
1462 	.get_next_id		= dquot_get_next_id,
1463 };
1464 
1465 static const struct quotactl_ops ext4_qctl_operations = {
1466 	.quota_on	= ext4_quota_on,
1467 	.quota_off	= ext4_quota_off,
1468 	.quota_sync	= dquot_quota_sync,
1469 	.get_state	= dquot_get_state,
1470 	.set_info	= dquot_set_dqinfo,
1471 	.get_dqblk	= dquot_get_dqblk,
1472 	.set_dqblk	= dquot_set_dqblk,
1473 	.get_nextdqblk	= dquot_get_next_dqblk,
1474 };
1475 #endif
1476 
1477 static const struct super_operations ext4_sops = {
1478 	.alloc_inode	= ext4_alloc_inode,
1479 	.free_inode	= ext4_free_in_core_inode,
1480 	.destroy_inode	= ext4_destroy_inode,
1481 	.write_inode	= ext4_write_inode,
1482 	.dirty_inode	= ext4_dirty_inode,
1483 	.drop_inode	= ext4_drop_inode,
1484 	.evict_inode	= ext4_evict_inode,
1485 	.put_super	= ext4_put_super,
1486 	.sync_fs	= ext4_sync_fs,
1487 	.freeze_fs	= ext4_freeze,
1488 	.unfreeze_fs	= ext4_unfreeze,
1489 	.statfs		= ext4_statfs,
1490 	.remount_fs	= ext4_remount,
1491 	.show_options	= ext4_show_options,
1492 #ifdef CONFIG_QUOTA
1493 	.quota_read	= ext4_quota_read,
1494 	.quota_write	= ext4_quota_write,
1495 	.get_dquots	= ext4_get_dquots,
1496 #endif
1497 	.bdev_try_to_free_page = bdev_try_to_free_page,
1498 };
1499 
1500 static const struct export_operations ext4_export_ops = {
1501 	.fh_to_dentry = ext4_fh_to_dentry,
1502 	.fh_to_parent = ext4_fh_to_parent,
1503 	.get_parent = ext4_get_parent,
1504 	.commit_metadata = ext4_nfs_commit_metadata,
1505 };
1506 
1507 enum {
1508 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1509 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1510 	Opt_nouid32, Opt_debug, Opt_removed,
1511 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1512 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1513 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1514 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1515 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1516 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1517 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1518 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1519 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1520 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1521 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1522 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1523 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1524 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1525 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1526 	Opt_dioread_nolock, Opt_dioread_lock,
1527 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1528 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1529 };
1530 
1531 static const match_table_t tokens = {
1532 	{Opt_bsd_df, "bsddf"},
1533 	{Opt_minix_df, "minixdf"},
1534 	{Opt_grpid, "grpid"},
1535 	{Opt_grpid, "bsdgroups"},
1536 	{Opt_nogrpid, "nogrpid"},
1537 	{Opt_nogrpid, "sysvgroups"},
1538 	{Opt_resgid, "resgid=%u"},
1539 	{Opt_resuid, "resuid=%u"},
1540 	{Opt_sb, "sb=%u"},
1541 	{Opt_err_cont, "errors=continue"},
1542 	{Opt_err_panic, "errors=panic"},
1543 	{Opt_err_ro, "errors=remount-ro"},
1544 	{Opt_nouid32, "nouid32"},
1545 	{Opt_debug, "debug"},
1546 	{Opt_removed, "oldalloc"},
1547 	{Opt_removed, "orlov"},
1548 	{Opt_user_xattr, "user_xattr"},
1549 	{Opt_nouser_xattr, "nouser_xattr"},
1550 	{Opt_acl, "acl"},
1551 	{Opt_noacl, "noacl"},
1552 	{Opt_noload, "norecovery"},
1553 	{Opt_noload, "noload"},
1554 	{Opt_removed, "nobh"},
1555 	{Opt_removed, "bh"},
1556 	{Opt_commit, "commit=%u"},
1557 	{Opt_min_batch_time, "min_batch_time=%u"},
1558 	{Opt_max_batch_time, "max_batch_time=%u"},
1559 	{Opt_journal_dev, "journal_dev=%u"},
1560 	{Opt_journal_path, "journal_path=%s"},
1561 	{Opt_journal_checksum, "journal_checksum"},
1562 	{Opt_nojournal_checksum, "nojournal_checksum"},
1563 	{Opt_journal_async_commit, "journal_async_commit"},
1564 	{Opt_abort, "abort"},
1565 	{Opt_data_journal, "data=journal"},
1566 	{Opt_data_ordered, "data=ordered"},
1567 	{Opt_data_writeback, "data=writeback"},
1568 	{Opt_data_err_abort, "data_err=abort"},
1569 	{Opt_data_err_ignore, "data_err=ignore"},
1570 	{Opt_offusrjquota, "usrjquota="},
1571 	{Opt_usrjquota, "usrjquota=%s"},
1572 	{Opt_offgrpjquota, "grpjquota="},
1573 	{Opt_grpjquota, "grpjquota=%s"},
1574 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1575 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1576 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1577 	{Opt_grpquota, "grpquota"},
1578 	{Opt_noquota, "noquota"},
1579 	{Opt_quota, "quota"},
1580 	{Opt_usrquota, "usrquota"},
1581 	{Opt_prjquota, "prjquota"},
1582 	{Opt_barrier, "barrier=%u"},
1583 	{Opt_barrier, "barrier"},
1584 	{Opt_nobarrier, "nobarrier"},
1585 	{Opt_i_version, "i_version"},
1586 	{Opt_dax, "dax"},
1587 	{Opt_stripe, "stripe=%u"},
1588 	{Opt_delalloc, "delalloc"},
1589 	{Opt_warn_on_error, "warn_on_error"},
1590 	{Opt_nowarn_on_error, "nowarn_on_error"},
1591 	{Opt_lazytime, "lazytime"},
1592 	{Opt_nolazytime, "nolazytime"},
1593 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1594 	{Opt_nodelalloc, "nodelalloc"},
1595 	{Opt_removed, "mblk_io_submit"},
1596 	{Opt_removed, "nomblk_io_submit"},
1597 	{Opt_block_validity, "block_validity"},
1598 	{Opt_noblock_validity, "noblock_validity"},
1599 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1600 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1601 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1602 	{Opt_auto_da_alloc, "auto_da_alloc"},
1603 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1604 	{Opt_dioread_nolock, "dioread_nolock"},
1605 	{Opt_dioread_lock, "nodioread_nolock"},
1606 	{Opt_dioread_lock, "dioread_lock"},
1607 	{Opt_discard, "discard"},
1608 	{Opt_nodiscard, "nodiscard"},
1609 	{Opt_init_itable, "init_itable=%u"},
1610 	{Opt_init_itable, "init_itable"},
1611 	{Opt_noinit_itable, "noinit_itable"},
1612 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1613 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1614 	{Opt_nombcache, "nombcache"},
1615 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1616 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1617 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1618 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1619 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1620 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1621 	{Opt_err, NULL},
1622 };
1623 
1624 static ext4_fsblk_t get_sb_block(void **data)
1625 {
1626 	ext4_fsblk_t	sb_block;
1627 	char		*options = (char *) *data;
1628 
1629 	if (!options || strncmp(options, "sb=", 3) != 0)
1630 		return 1;	/* Default location */
1631 
1632 	options += 3;
1633 	/* TODO: use simple_strtoll with >32bit ext4 */
1634 	sb_block = simple_strtoul(options, &options, 0);
1635 	if (*options && *options != ',') {
1636 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1637 		       (char *) *data);
1638 		return 1;
1639 	}
1640 	if (*options == ',')
1641 		options++;
1642 	*data = (void *) options;
1643 
1644 	return sb_block;
1645 }
1646 
1647 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1648 static const char deprecated_msg[] =
1649 	"Mount option \"%s\" will be removed by %s\n"
1650 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1651 
1652 #ifdef CONFIG_QUOTA
1653 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1654 {
1655 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1656 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1657 	int ret = -1;
1658 
1659 	if (sb_any_quota_loaded(sb) && !old_qname) {
1660 		ext4_msg(sb, KERN_ERR,
1661 			"Cannot change journaled "
1662 			"quota options when quota turned on");
1663 		return -1;
1664 	}
1665 	if (ext4_has_feature_quota(sb)) {
1666 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1667 			 "ignored when QUOTA feature is enabled");
1668 		return 1;
1669 	}
1670 	qname = match_strdup(args);
1671 	if (!qname) {
1672 		ext4_msg(sb, KERN_ERR,
1673 			"Not enough memory for storing quotafile name");
1674 		return -1;
1675 	}
1676 	if (old_qname) {
1677 		if (strcmp(old_qname, qname) == 0)
1678 			ret = 1;
1679 		else
1680 			ext4_msg(sb, KERN_ERR,
1681 				 "%s quota file already specified",
1682 				 QTYPE2NAME(qtype));
1683 		goto errout;
1684 	}
1685 	if (strchr(qname, '/')) {
1686 		ext4_msg(sb, KERN_ERR,
1687 			"quotafile must be on filesystem root");
1688 		goto errout;
1689 	}
1690 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1691 	set_opt(sb, QUOTA);
1692 	return 1;
1693 errout:
1694 	kfree(qname);
1695 	return ret;
1696 }
1697 
1698 static int clear_qf_name(struct super_block *sb, int qtype)
1699 {
1700 
1701 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1702 	char *old_qname = get_qf_name(sb, sbi, qtype);
1703 
1704 	if (sb_any_quota_loaded(sb) && old_qname) {
1705 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1706 			" when quota turned on");
1707 		return -1;
1708 	}
1709 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1710 	synchronize_rcu();
1711 	kfree(old_qname);
1712 	return 1;
1713 }
1714 #endif
1715 
1716 #define MOPT_SET	0x0001
1717 #define MOPT_CLEAR	0x0002
1718 #define MOPT_NOSUPPORT	0x0004
1719 #define MOPT_EXPLICIT	0x0008
1720 #define MOPT_CLEAR_ERR	0x0010
1721 #define MOPT_GTE0	0x0020
1722 #ifdef CONFIG_QUOTA
1723 #define MOPT_Q		0
1724 #define MOPT_QFMT	0x0040
1725 #else
1726 #define MOPT_Q		MOPT_NOSUPPORT
1727 #define MOPT_QFMT	MOPT_NOSUPPORT
1728 #endif
1729 #define MOPT_DATAJ	0x0080
1730 #define MOPT_NO_EXT2	0x0100
1731 #define MOPT_NO_EXT3	0x0200
1732 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1733 #define MOPT_STRING	0x0400
1734 
1735 static const struct mount_opts {
1736 	int	token;
1737 	int	mount_opt;
1738 	int	flags;
1739 } ext4_mount_opts[] = {
1740 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1741 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1742 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1743 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1744 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1745 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1746 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1747 	 MOPT_EXT4_ONLY | MOPT_SET},
1748 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1749 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1750 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1751 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1752 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1753 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1754 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1755 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1756 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1757 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1758 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1759 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1760 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1761 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1762 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1763 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1764 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1765 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1766 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1767 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1768 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1769 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1770 	 MOPT_NO_EXT2},
1771 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1772 	 MOPT_NO_EXT2},
1773 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1774 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1775 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1776 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1777 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1778 	{Opt_commit, 0, MOPT_GTE0},
1779 	{Opt_max_batch_time, 0, MOPT_GTE0},
1780 	{Opt_min_batch_time, 0, MOPT_GTE0},
1781 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1782 	{Opt_init_itable, 0, MOPT_GTE0},
1783 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1784 	{Opt_stripe, 0, MOPT_GTE0},
1785 	{Opt_resuid, 0, MOPT_GTE0},
1786 	{Opt_resgid, 0, MOPT_GTE0},
1787 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1788 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1789 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1790 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1791 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1792 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1793 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1794 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1795 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1796 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1797 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1798 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1799 #else
1800 	{Opt_acl, 0, MOPT_NOSUPPORT},
1801 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1802 #endif
1803 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1804 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1805 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1806 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1807 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1808 							MOPT_SET | MOPT_Q},
1809 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1810 							MOPT_SET | MOPT_Q},
1811 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1812 							MOPT_SET | MOPT_Q},
1813 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1814 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1815 							MOPT_CLEAR | MOPT_Q},
1816 	{Opt_usrjquota, 0, MOPT_Q},
1817 	{Opt_grpjquota, 0, MOPT_Q},
1818 	{Opt_offusrjquota, 0, MOPT_Q},
1819 	{Opt_offgrpjquota, 0, MOPT_Q},
1820 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1821 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1822 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1823 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1824 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1825 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1826 	{Opt_err, 0, 0}
1827 };
1828 
1829 #ifdef CONFIG_UNICODE
1830 static const struct ext4_sb_encodings {
1831 	__u16 magic;
1832 	char *name;
1833 	char *version;
1834 } ext4_sb_encoding_map[] = {
1835 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1836 };
1837 
1838 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1839 				 const struct ext4_sb_encodings **encoding,
1840 				 __u16 *flags)
1841 {
1842 	__u16 magic = le16_to_cpu(es->s_encoding);
1843 	int i;
1844 
1845 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1846 		if (magic == ext4_sb_encoding_map[i].magic)
1847 			break;
1848 
1849 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1850 		return -EINVAL;
1851 
1852 	*encoding = &ext4_sb_encoding_map[i];
1853 	*flags = le16_to_cpu(es->s_encoding_flags);
1854 
1855 	return 0;
1856 }
1857 #endif
1858 
1859 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1860 			    substring_t *args, unsigned long *journal_devnum,
1861 			    unsigned int *journal_ioprio, int is_remount)
1862 {
1863 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1864 	const struct mount_opts *m;
1865 	kuid_t uid;
1866 	kgid_t gid;
1867 	int arg = 0;
1868 
1869 #ifdef CONFIG_QUOTA
1870 	if (token == Opt_usrjquota)
1871 		return set_qf_name(sb, USRQUOTA, &args[0]);
1872 	else if (token == Opt_grpjquota)
1873 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1874 	else if (token == Opt_offusrjquota)
1875 		return clear_qf_name(sb, USRQUOTA);
1876 	else if (token == Opt_offgrpjquota)
1877 		return clear_qf_name(sb, GRPQUOTA);
1878 #endif
1879 	switch (token) {
1880 	case Opt_noacl:
1881 	case Opt_nouser_xattr:
1882 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1883 		break;
1884 	case Opt_sb:
1885 		return 1;	/* handled by get_sb_block() */
1886 	case Opt_removed:
1887 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1888 		return 1;
1889 	case Opt_abort:
1890 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1891 		return 1;
1892 	case Opt_i_version:
1893 		sb->s_flags |= SB_I_VERSION;
1894 		return 1;
1895 	case Opt_lazytime:
1896 		sb->s_flags |= SB_LAZYTIME;
1897 		return 1;
1898 	case Opt_nolazytime:
1899 		sb->s_flags &= ~SB_LAZYTIME;
1900 		return 1;
1901 	}
1902 
1903 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1904 		if (token == m->token)
1905 			break;
1906 
1907 	if (m->token == Opt_err) {
1908 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1909 			 "or missing value", opt);
1910 		return -1;
1911 	}
1912 
1913 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1914 		ext4_msg(sb, KERN_ERR,
1915 			 "Mount option \"%s\" incompatible with ext2", opt);
1916 		return -1;
1917 	}
1918 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1919 		ext4_msg(sb, KERN_ERR,
1920 			 "Mount option \"%s\" incompatible with ext3", opt);
1921 		return -1;
1922 	}
1923 
1924 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1925 		return -1;
1926 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1927 		return -1;
1928 	if (m->flags & MOPT_EXPLICIT) {
1929 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1930 			set_opt2(sb, EXPLICIT_DELALLOC);
1931 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1932 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1933 		} else
1934 			return -1;
1935 	}
1936 	if (m->flags & MOPT_CLEAR_ERR)
1937 		clear_opt(sb, ERRORS_MASK);
1938 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1939 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1940 			 "options when quota turned on");
1941 		return -1;
1942 	}
1943 
1944 	if (m->flags & MOPT_NOSUPPORT) {
1945 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1946 	} else if (token == Opt_commit) {
1947 		if (arg == 0)
1948 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1949 		else if (arg > INT_MAX / HZ) {
1950 			ext4_msg(sb, KERN_ERR,
1951 				 "Invalid commit interval %d, "
1952 				 "must be smaller than %d",
1953 				 arg, INT_MAX / HZ);
1954 			return -1;
1955 		}
1956 		sbi->s_commit_interval = HZ * arg;
1957 	} else if (token == Opt_debug_want_extra_isize) {
1958 		if ((arg & 1) ||
1959 		    (arg < 4) ||
1960 		    (arg > (sbi->s_inode_size - EXT4_GOOD_OLD_INODE_SIZE))) {
1961 			ext4_msg(sb, KERN_ERR,
1962 				 "Invalid want_extra_isize %d", arg);
1963 			return -1;
1964 		}
1965 		sbi->s_want_extra_isize = arg;
1966 	} else if (token == Opt_max_batch_time) {
1967 		sbi->s_max_batch_time = arg;
1968 	} else if (token == Opt_min_batch_time) {
1969 		sbi->s_min_batch_time = arg;
1970 	} else if (token == Opt_inode_readahead_blks) {
1971 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1972 			ext4_msg(sb, KERN_ERR,
1973 				 "EXT4-fs: inode_readahead_blks must be "
1974 				 "0 or a power of 2 smaller than 2^31");
1975 			return -1;
1976 		}
1977 		sbi->s_inode_readahead_blks = arg;
1978 	} else if (token == Opt_init_itable) {
1979 		set_opt(sb, INIT_INODE_TABLE);
1980 		if (!args->from)
1981 			arg = EXT4_DEF_LI_WAIT_MULT;
1982 		sbi->s_li_wait_mult = arg;
1983 	} else if (token == Opt_max_dir_size_kb) {
1984 		sbi->s_max_dir_size_kb = arg;
1985 	} else if (token == Opt_stripe) {
1986 		sbi->s_stripe = arg;
1987 	} else if (token == Opt_resuid) {
1988 		uid = make_kuid(current_user_ns(), arg);
1989 		if (!uid_valid(uid)) {
1990 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1991 			return -1;
1992 		}
1993 		sbi->s_resuid = uid;
1994 	} else if (token == Opt_resgid) {
1995 		gid = make_kgid(current_user_ns(), arg);
1996 		if (!gid_valid(gid)) {
1997 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1998 			return -1;
1999 		}
2000 		sbi->s_resgid = gid;
2001 	} else if (token == Opt_journal_dev) {
2002 		if (is_remount) {
2003 			ext4_msg(sb, KERN_ERR,
2004 				 "Cannot specify journal on remount");
2005 			return -1;
2006 		}
2007 		*journal_devnum = arg;
2008 	} else if (token == Opt_journal_path) {
2009 		char *journal_path;
2010 		struct inode *journal_inode;
2011 		struct path path;
2012 		int error;
2013 
2014 		if (is_remount) {
2015 			ext4_msg(sb, KERN_ERR,
2016 				 "Cannot specify journal on remount");
2017 			return -1;
2018 		}
2019 		journal_path = match_strdup(&args[0]);
2020 		if (!journal_path) {
2021 			ext4_msg(sb, KERN_ERR, "error: could not dup "
2022 				"journal device string");
2023 			return -1;
2024 		}
2025 
2026 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
2027 		if (error) {
2028 			ext4_msg(sb, KERN_ERR, "error: could not find "
2029 				"journal device path: error %d", error);
2030 			kfree(journal_path);
2031 			return -1;
2032 		}
2033 
2034 		journal_inode = d_inode(path.dentry);
2035 		if (!S_ISBLK(journal_inode->i_mode)) {
2036 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
2037 				"is not a block device", journal_path);
2038 			path_put(&path);
2039 			kfree(journal_path);
2040 			return -1;
2041 		}
2042 
2043 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
2044 		path_put(&path);
2045 		kfree(journal_path);
2046 	} else if (token == Opt_journal_ioprio) {
2047 		if (arg > 7) {
2048 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
2049 				 " (must be 0-7)");
2050 			return -1;
2051 		}
2052 		*journal_ioprio =
2053 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
2054 	} else if (token == Opt_test_dummy_encryption) {
2055 #ifdef CONFIG_FS_ENCRYPTION
2056 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
2057 		ext4_msg(sb, KERN_WARNING,
2058 			 "Test dummy encryption mode enabled");
2059 #else
2060 		ext4_msg(sb, KERN_WARNING,
2061 			 "Test dummy encryption mount option ignored");
2062 #endif
2063 	} else if (m->flags & MOPT_DATAJ) {
2064 		if (is_remount) {
2065 			if (!sbi->s_journal)
2066 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2067 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2068 				ext4_msg(sb, KERN_ERR,
2069 					 "Cannot change data mode on remount");
2070 				return -1;
2071 			}
2072 		} else {
2073 			clear_opt(sb, DATA_FLAGS);
2074 			sbi->s_mount_opt |= m->mount_opt;
2075 		}
2076 #ifdef CONFIG_QUOTA
2077 	} else if (m->flags & MOPT_QFMT) {
2078 		if (sb_any_quota_loaded(sb) &&
2079 		    sbi->s_jquota_fmt != m->mount_opt) {
2080 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2081 				 "quota options when quota turned on");
2082 			return -1;
2083 		}
2084 		if (ext4_has_feature_quota(sb)) {
2085 			ext4_msg(sb, KERN_INFO,
2086 				 "Quota format mount options ignored "
2087 				 "when QUOTA feature is enabled");
2088 			return 1;
2089 		}
2090 		sbi->s_jquota_fmt = m->mount_opt;
2091 #endif
2092 	} else if (token == Opt_dax) {
2093 #ifdef CONFIG_FS_DAX
2094 		ext4_msg(sb, KERN_WARNING,
2095 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2096 		sbi->s_mount_opt |= m->mount_opt;
2097 #else
2098 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2099 		return -1;
2100 #endif
2101 	} else if (token == Opt_data_err_abort) {
2102 		sbi->s_mount_opt |= m->mount_opt;
2103 	} else if (token == Opt_data_err_ignore) {
2104 		sbi->s_mount_opt &= ~m->mount_opt;
2105 	} else {
2106 		if (!args->from)
2107 			arg = 1;
2108 		if (m->flags & MOPT_CLEAR)
2109 			arg = !arg;
2110 		else if (unlikely(!(m->flags & MOPT_SET))) {
2111 			ext4_msg(sb, KERN_WARNING,
2112 				 "buggy handling of option %s", opt);
2113 			WARN_ON(1);
2114 			return -1;
2115 		}
2116 		if (arg != 0)
2117 			sbi->s_mount_opt |= m->mount_opt;
2118 		else
2119 			sbi->s_mount_opt &= ~m->mount_opt;
2120 	}
2121 	return 1;
2122 }
2123 
2124 static int parse_options(char *options, struct super_block *sb,
2125 			 unsigned long *journal_devnum,
2126 			 unsigned int *journal_ioprio,
2127 			 int is_remount)
2128 {
2129 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2130 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2131 	substring_t args[MAX_OPT_ARGS];
2132 	int token;
2133 
2134 	if (!options)
2135 		return 1;
2136 
2137 	while ((p = strsep(&options, ",")) != NULL) {
2138 		if (!*p)
2139 			continue;
2140 		/*
2141 		 * Initialize args struct so we know whether arg was
2142 		 * found; some options take optional arguments.
2143 		 */
2144 		args[0].to = args[0].from = NULL;
2145 		token = match_token(p, tokens, args);
2146 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2147 				     journal_ioprio, is_remount) < 0)
2148 			return 0;
2149 	}
2150 #ifdef CONFIG_QUOTA
2151 	/*
2152 	 * We do the test below only for project quotas. 'usrquota' and
2153 	 * 'grpquota' mount options are allowed even without quota feature
2154 	 * to support legacy quotas in quota files.
2155 	 */
2156 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2157 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2158 			 "Cannot enable project quota enforcement.");
2159 		return 0;
2160 	}
2161 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2162 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2163 	if (usr_qf_name || grp_qf_name) {
2164 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2165 			clear_opt(sb, USRQUOTA);
2166 
2167 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2168 			clear_opt(sb, GRPQUOTA);
2169 
2170 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2171 			ext4_msg(sb, KERN_ERR, "old and new quota "
2172 					"format mixing");
2173 			return 0;
2174 		}
2175 
2176 		if (!sbi->s_jquota_fmt) {
2177 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2178 					"not specified");
2179 			return 0;
2180 		}
2181 	}
2182 #endif
2183 	return 1;
2184 }
2185 
2186 static inline void ext4_show_quota_options(struct seq_file *seq,
2187 					   struct super_block *sb)
2188 {
2189 #if defined(CONFIG_QUOTA)
2190 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2191 	char *usr_qf_name, *grp_qf_name;
2192 
2193 	if (sbi->s_jquota_fmt) {
2194 		char *fmtname = "";
2195 
2196 		switch (sbi->s_jquota_fmt) {
2197 		case QFMT_VFS_OLD:
2198 			fmtname = "vfsold";
2199 			break;
2200 		case QFMT_VFS_V0:
2201 			fmtname = "vfsv0";
2202 			break;
2203 		case QFMT_VFS_V1:
2204 			fmtname = "vfsv1";
2205 			break;
2206 		}
2207 		seq_printf(seq, ",jqfmt=%s", fmtname);
2208 	}
2209 
2210 	rcu_read_lock();
2211 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2212 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2213 	if (usr_qf_name)
2214 		seq_show_option(seq, "usrjquota", usr_qf_name);
2215 	if (grp_qf_name)
2216 		seq_show_option(seq, "grpjquota", grp_qf_name);
2217 	rcu_read_unlock();
2218 #endif
2219 }
2220 
2221 static const char *token2str(int token)
2222 {
2223 	const struct match_token *t;
2224 
2225 	for (t = tokens; t->token != Opt_err; t++)
2226 		if (t->token == token && !strchr(t->pattern, '='))
2227 			break;
2228 	return t->pattern;
2229 }
2230 
2231 /*
2232  * Show an option if
2233  *  - it's set to a non-default value OR
2234  *  - if the per-sb default is different from the global default
2235  */
2236 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2237 			      int nodefs)
2238 {
2239 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2240 	struct ext4_super_block *es = sbi->s_es;
2241 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2242 	const struct mount_opts *m;
2243 	char sep = nodefs ? '\n' : ',';
2244 
2245 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2246 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2247 
2248 	if (sbi->s_sb_block != 1)
2249 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2250 
2251 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2252 		int want_set = m->flags & MOPT_SET;
2253 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2254 		    (m->flags & MOPT_CLEAR_ERR))
2255 			continue;
2256 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2257 			continue; /* skip if same as the default */
2258 		if ((want_set &&
2259 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2260 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2261 			continue; /* select Opt_noFoo vs Opt_Foo */
2262 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2263 	}
2264 
2265 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2266 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2267 		SEQ_OPTS_PRINT("resuid=%u",
2268 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2269 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2270 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2271 		SEQ_OPTS_PRINT("resgid=%u",
2272 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2273 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2274 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2275 		SEQ_OPTS_PUTS("errors=remount-ro");
2276 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2277 		SEQ_OPTS_PUTS("errors=continue");
2278 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2279 		SEQ_OPTS_PUTS("errors=panic");
2280 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2281 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2282 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2283 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2284 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2285 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2286 	if (sb->s_flags & SB_I_VERSION)
2287 		SEQ_OPTS_PUTS("i_version");
2288 	if (nodefs || sbi->s_stripe)
2289 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2290 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2291 			(sbi->s_mount_opt ^ def_mount_opt)) {
2292 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2293 			SEQ_OPTS_PUTS("data=journal");
2294 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2295 			SEQ_OPTS_PUTS("data=ordered");
2296 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2297 			SEQ_OPTS_PUTS("data=writeback");
2298 	}
2299 	if (nodefs ||
2300 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2301 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2302 			       sbi->s_inode_readahead_blks);
2303 
2304 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2305 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2306 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2307 	if (nodefs || sbi->s_max_dir_size_kb)
2308 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2309 	if (test_opt(sb, DATA_ERR_ABORT))
2310 		SEQ_OPTS_PUTS("data_err=abort");
2311 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2312 		SEQ_OPTS_PUTS("test_dummy_encryption");
2313 
2314 	ext4_show_quota_options(seq, sb);
2315 	return 0;
2316 }
2317 
2318 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2319 {
2320 	return _ext4_show_options(seq, root->d_sb, 0);
2321 }
2322 
2323 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2324 {
2325 	struct super_block *sb = seq->private;
2326 	int rc;
2327 
2328 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2329 	rc = _ext4_show_options(seq, sb, 1);
2330 	seq_puts(seq, "\n");
2331 	return rc;
2332 }
2333 
2334 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2335 			    int read_only)
2336 {
2337 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2338 	int err = 0;
2339 
2340 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2341 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2342 			 "forcing read-only mode");
2343 		err = -EROFS;
2344 	}
2345 	if (read_only)
2346 		goto done;
2347 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2348 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2349 			 "running e2fsck is recommended");
2350 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2351 		ext4_msg(sb, KERN_WARNING,
2352 			 "warning: mounting fs with errors, "
2353 			 "running e2fsck is recommended");
2354 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2355 		 le16_to_cpu(es->s_mnt_count) >=
2356 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2357 		ext4_msg(sb, KERN_WARNING,
2358 			 "warning: maximal mount count reached, "
2359 			 "running e2fsck is recommended");
2360 	else if (le32_to_cpu(es->s_checkinterval) &&
2361 		 (ext4_get_tstamp(es, s_lastcheck) +
2362 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2363 		ext4_msg(sb, KERN_WARNING,
2364 			 "warning: checktime reached, "
2365 			 "running e2fsck is recommended");
2366 	if (!sbi->s_journal)
2367 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2368 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2369 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2370 	le16_add_cpu(&es->s_mnt_count, 1);
2371 	ext4_update_tstamp(es, s_mtime);
2372 	if (sbi->s_journal)
2373 		ext4_set_feature_journal_needs_recovery(sb);
2374 
2375 	err = ext4_commit_super(sb, 1);
2376 done:
2377 	if (test_opt(sb, DEBUG))
2378 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2379 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2380 			sb->s_blocksize,
2381 			sbi->s_groups_count,
2382 			EXT4_BLOCKS_PER_GROUP(sb),
2383 			EXT4_INODES_PER_GROUP(sb),
2384 			sbi->s_mount_opt, sbi->s_mount_opt2);
2385 
2386 	cleancache_init_fs(sb);
2387 	return err;
2388 }
2389 
2390 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2391 {
2392 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2393 	struct flex_groups **old_groups, **new_groups;
2394 	int size, i, j;
2395 
2396 	if (!sbi->s_log_groups_per_flex)
2397 		return 0;
2398 
2399 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2400 	if (size <= sbi->s_flex_groups_allocated)
2401 		return 0;
2402 
2403 	new_groups = kvzalloc(roundup_pow_of_two(size *
2404 			      sizeof(*sbi->s_flex_groups)), GFP_KERNEL);
2405 	if (!new_groups) {
2406 		ext4_msg(sb, KERN_ERR,
2407 			 "not enough memory for %d flex group pointers", size);
2408 		return -ENOMEM;
2409 	}
2410 	for (i = sbi->s_flex_groups_allocated; i < size; i++) {
2411 		new_groups[i] = kvzalloc(roundup_pow_of_two(
2412 					 sizeof(struct flex_groups)),
2413 					 GFP_KERNEL);
2414 		if (!new_groups[i]) {
2415 			for (j = sbi->s_flex_groups_allocated; j < i; j++)
2416 				kvfree(new_groups[j]);
2417 			kvfree(new_groups);
2418 			ext4_msg(sb, KERN_ERR,
2419 				 "not enough memory for %d flex groups", size);
2420 			return -ENOMEM;
2421 		}
2422 	}
2423 	rcu_read_lock();
2424 	old_groups = rcu_dereference(sbi->s_flex_groups);
2425 	if (old_groups)
2426 		memcpy(new_groups, old_groups,
2427 		       (sbi->s_flex_groups_allocated *
2428 			sizeof(struct flex_groups *)));
2429 	rcu_read_unlock();
2430 	rcu_assign_pointer(sbi->s_flex_groups, new_groups);
2431 	sbi->s_flex_groups_allocated = size;
2432 	if (old_groups)
2433 		ext4_kvfree_array_rcu(old_groups);
2434 	return 0;
2435 }
2436 
2437 static int ext4_fill_flex_info(struct super_block *sb)
2438 {
2439 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2440 	struct ext4_group_desc *gdp = NULL;
2441 	struct flex_groups *fg;
2442 	ext4_group_t flex_group;
2443 	int i, err;
2444 
2445 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2446 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2447 		sbi->s_log_groups_per_flex = 0;
2448 		return 1;
2449 	}
2450 
2451 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2452 	if (err)
2453 		goto failed;
2454 
2455 	for (i = 0; i < sbi->s_groups_count; i++) {
2456 		gdp = ext4_get_group_desc(sb, i, NULL);
2457 
2458 		flex_group = ext4_flex_group(sbi, i);
2459 		fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group);
2460 		atomic_add(ext4_free_inodes_count(sb, gdp), &fg->free_inodes);
2461 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2462 			     &fg->free_clusters);
2463 		atomic_add(ext4_used_dirs_count(sb, gdp), &fg->used_dirs);
2464 	}
2465 
2466 	return 1;
2467 failed:
2468 	return 0;
2469 }
2470 
2471 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2472 				   struct ext4_group_desc *gdp)
2473 {
2474 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2475 	__u16 crc = 0;
2476 	__le32 le_group = cpu_to_le32(block_group);
2477 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2478 
2479 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2480 		/* Use new metadata_csum algorithm */
2481 		__u32 csum32;
2482 		__u16 dummy_csum = 0;
2483 
2484 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2485 				     sizeof(le_group));
2486 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2487 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2488 				     sizeof(dummy_csum));
2489 		offset += sizeof(dummy_csum);
2490 		if (offset < sbi->s_desc_size)
2491 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2492 					     sbi->s_desc_size - offset);
2493 
2494 		crc = csum32 & 0xFFFF;
2495 		goto out;
2496 	}
2497 
2498 	/* old crc16 code */
2499 	if (!ext4_has_feature_gdt_csum(sb))
2500 		return 0;
2501 
2502 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2503 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2504 	crc = crc16(crc, (__u8 *)gdp, offset);
2505 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2506 	/* for checksum of struct ext4_group_desc do the rest...*/
2507 	if (ext4_has_feature_64bit(sb) &&
2508 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2509 		crc = crc16(crc, (__u8 *)gdp + offset,
2510 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2511 				offset);
2512 
2513 out:
2514 	return cpu_to_le16(crc);
2515 }
2516 
2517 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2518 				struct ext4_group_desc *gdp)
2519 {
2520 	if (ext4_has_group_desc_csum(sb) &&
2521 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2522 		return 0;
2523 
2524 	return 1;
2525 }
2526 
2527 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2528 			      struct ext4_group_desc *gdp)
2529 {
2530 	if (!ext4_has_group_desc_csum(sb))
2531 		return;
2532 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2533 }
2534 
2535 /* Called at mount-time, super-block is locked */
2536 static int ext4_check_descriptors(struct super_block *sb,
2537 				  ext4_fsblk_t sb_block,
2538 				  ext4_group_t *first_not_zeroed)
2539 {
2540 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2541 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2542 	ext4_fsblk_t last_block;
2543 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2544 	ext4_fsblk_t block_bitmap;
2545 	ext4_fsblk_t inode_bitmap;
2546 	ext4_fsblk_t inode_table;
2547 	int flexbg_flag = 0;
2548 	ext4_group_t i, grp = sbi->s_groups_count;
2549 
2550 	if (ext4_has_feature_flex_bg(sb))
2551 		flexbg_flag = 1;
2552 
2553 	ext4_debug("Checking group descriptors");
2554 
2555 	for (i = 0; i < sbi->s_groups_count; i++) {
2556 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2557 
2558 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2559 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2560 		else
2561 			last_block = first_block +
2562 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2563 
2564 		if ((grp == sbi->s_groups_count) &&
2565 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2566 			grp = i;
2567 
2568 		block_bitmap = ext4_block_bitmap(sb, gdp);
2569 		if (block_bitmap == sb_block) {
2570 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2571 				 "Block bitmap for group %u overlaps "
2572 				 "superblock", i);
2573 			if (!sb_rdonly(sb))
2574 				return 0;
2575 		}
2576 		if (block_bitmap >= sb_block + 1 &&
2577 		    block_bitmap <= last_bg_block) {
2578 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2579 				 "Block bitmap for group %u overlaps "
2580 				 "block group descriptors", i);
2581 			if (!sb_rdonly(sb))
2582 				return 0;
2583 		}
2584 		if (block_bitmap < first_block || block_bitmap > last_block) {
2585 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2586 			       "Block bitmap for group %u not in group "
2587 			       "(block %llu)!", i, block_bitmap);
2588 			return 0;
2589 		}
2590 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2591 		if (inode_bitmap == sb_block) {
2592 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2593 				 "Inode bitmap for group %u overlaps "
2594 				 "superblock", i);
2595 			if (!sb_rdonly(sb))
2596 				return 0;
2597 		}
2598 		if (inode_bitmap >= sb_block + 1 &&
2599 		    inode_bitmap <= last_bg_block) {
2600 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2601 				 "Inode bitmap for group %u overlaps "
2602 				 "block group descriptors", i);
2603 			if (!sb_rdonly(sb))
2604 				return 0;
2605 		}
2606 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2607 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2608 			       "Inode bitmap for group %u not in group "
2609 			       "(block %llu)!", i, inode_bitmap);
2610 			return 0;
2611 		}
2612 		inode_table = ext4_inode_table(sb, gdp);
2613 		if (inode_table == sb_block) {
2614 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2615 				 "Inode table for group %u overlaps "
2616 				 "superblock", i);
2617 			if (!sb_rdonly(sb))
2618 				return 0;
2619 		}
2620 		if (inode_table >= sb_block + 1 &&
2621 		    inode_table <= last_bg_block) {
2622 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2623 				 "Inode table for group %u overlaps "
2624 				 "block group descriptors", i);
2625 			if (!sb_rdonly(sb))
2626 				return 0;
2627 		}
2628 		if (inode_table < first_block ||
2629 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2630 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2631 			       "Inode table for group %u not in group "
2632 			       "(block %llu)!", i, inode_table);
2633 			return 0;
2634 		}
2635 		ext4_lock_group(sb, i);
2636 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2637 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2638 				 "Checksum for group %u failed (%u!=%u)",
2639 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2640 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2641 			if (!sb_rdonly(sb)) {
2642 				ext4_unlock_group(sb, i);
2643 				return 0;
2644 			}
2645 		}
2646 		ext4_unlock_group(sb, i);
2647 		if (!flexbg_flag)
2648 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2649 	}
2650 	if (NULL != first_not_zeroed)
2651 		*first_not_zeroed = grp;
2652 	return 1;
2653 }
2654 
2655 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2656  * the superblock) which were deleted from all directories, but held open by
2657  * a process at the time of a crash.  We walk the list and try to delete these
2658  * inodes at recovery time (only with a read-write filesystem).
2659  *
2660  * In order to keep the orphan inode chain consistent during traversal (in
2661  * case of crash during recovery), we link each inode into the superblock
2662  * orphan list_head and handle it the same way as an inode deletion during
2663  * normal operation (which journals the operations for us).
2664  *
2665  * We only do an iget() and an iput() on each inode, which is very safe if we
2666  * accidentally point at an in-use or already deleted inode.  The worst that
2667  * can happen in this case is that we get a "bit already cleared" message from
2668  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2669  * e2fsck was run on this filesystem, and it must have already done the orphan
2670  * inode cleanup for us, so we can safely abort without any further action.
2671  */
2672 static void ext4_orphan_cleanup(struct super_block *sb,
2673 				struct ext4_super_block *es)
2674 {
2675 	unsigned int s_flags = sb->s_flags;
2676 	int ret, nr_orphans = 0, nr_truncates = 0;
2677 #ifdef CONFIG_QUOTA
2678 	int quota_update = 0;
2679 	int i;
2680 #endif
2681 	if (!es->s_last_orphan) {
2682 		jbd_debug(4, "no orphan inodes to clean up\n");
2683 		return;
2684 	}
2685 
2686 	if (bdev_read_only(sb->s_bdev)) {
2687 		ext4_msg(sb, KERN_ERR, "write access "
2688 			"unavailable, skipping orphan cleanup");
2689 		return;
2690 	}
2691 
2692 	/* Check if feature set would not allow a r/w mount */
2693 	if (!ext4_feature_set_ok(sb, 0)) {
2694 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2695 			 "unknown ROCOMPAT features");
2696 		return;
2697 	}
2698 
2699 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2700 		/* don't clear list on RO mount w/ errors */
2701 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2702 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2703 				  "clearing orphan list.\n");
2704 			es->s_last_orphan = 0;
2705 		}
2706 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2707 		return;
2708 	}
2709 
2710 	if (s_flags & SB_RDONLY) {
2711 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2712 		sb->s_flags &= ~SB_RDONLY;
2713 	}
2714 #ifdef CONFIG_QUOTA
2715 	/* Needed for iput() to work correctly and not trash data */
2716 	sb->s_flags |= SB_ACTIVE;
2717 
2718 	/*
2719 	 * Turn on quotas which were not enabled for read-only mounts if
2720 	 * filesystem has quota feature, so that they are updated correctly.
2721 	 */
2722 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2723 		int ret = ext4_enable_quotas(sb);
2724 
2725 		if (!ret)
2726 			quota_update = 1;
2727 		else
2728 			ext4_msg(sb, KERN_ERR,
2729 				"Cannot turn on quotas: error %d", ret);
2730 	}
2731 
2732 	/* Turn on journaled quotas used for old sytle */
2733 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2734 		if (EXT4_SB(sb)->s_qf_names[i]) {
2735 			int ret = ext4_quota_on_mount(sb, i);
2736 
2737 			if (!ret)
2738 				quota_update = 1;
2739 			else
2740 				ext4_msg(sb, KERN_ERR,
2741 					"Cannot turn on journaled "
2742 					"quota: type %d: error %d", i, ret);
2743 		}
2744 	}
2745 #endif
2746 
2747 	while (es->s_last_orphan) {
2748 		struct inode *inode;
2749 
2750 		/*
2751 		 * We may have encountered an error during cleanup; if
2752 		 * so, skip the rest.
2753 		 */
2754 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2755 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2756 			es->s_last_orphan = 0;
2757 			break;
2758 		}
2759 
2760 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2761 		if (IS_ERR(inode)) {
2762 			es->s_last_orphan = 0;
2763 			break;
2764 		}
2765 
2766 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2767 		dquot_initialize(inode);
2768 		if (inode->i_nlink) {
2769 			if (test_opt(sb, DEBUG))
2770 				ext4_msg(sb, KERN_DEBUG,
2771 					"%s: truncating inode %lu to %lld bytes",
2772 					__func__, inode->i_ino, inode->i_size);
2773 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2774 				  inode->i_ino, inode->i_size);
2775 			inode_lock(inode);
2776 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2777 			ret = ext4_truncate(inode);
2778 			if (ret)
2779 				ext4_std_error(inode->i_sb, ret);
2780 			inode_unlock(inode);
2781 			nr_truncates++;
2782 		} else {
2783 			if (test_opt(sb, DEBUG))
2784 				ext4_msg(sb, KERN_DEBUG,
2785 					"%s: deleting unreferenced inode %lu",
2786 					__func__, inode->i_ino);
2787 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2788 				  inode->i_ino);
2789 			nr_orphans++;
2790 		}
2791 		iput(inode);  /* The delete magic happens here! */
2792 	}
2793 
2794 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2795 
2796 	if (nr_orphans)
2797 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2798 		       PLURAL(nr_orphans));
2799 	if (nr_truncates)
2800 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2801 		       PLURAL(nr_truncates));
2802 #ifdef CONFIG_QUOTA
2803 	/* Turn off quotas if they were enabled for orphan cleanup */
2804 	if (quota_update) {
2805 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2806 			if (sb_dqopt(sb)->files[i])
2807 				dquot_quota_off(sb, i);
2808 		}
2809 	}
2810 #endif
2811 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2812 }
2813 
2814 /*
2815  * Maximal extent format file size.
2816  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2817  * extent format containers, within a sector_t, and within i_blocks
2818  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2819  * so that won't be a limiting factor.
2820  *
2821  * However there is other limiting factor. We do store extents in the form
2822  * of starting block and length, hence the resulting length of the extent
2823  * covering maximum file size must fit into on-disk format containers as
2824  * well. Given that length is always by 1 unit bigger than max unit (because
2825  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2826  *
2827  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2828  */
2829 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2830 {
2831 	loff_t res;
2832 	loff_t upper_limit = MAX_LFS_FILESIZE;
2833 
2834 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2835 
2836 	if (!has_huge_files) {
2837 		upper_limit = (1LL << 32) - 1;
2838 
2839 		/* total blocks in file system block size */
2840 		upper_limit >>= (blkbits - 9);
2841 		upper_limit <<= blkbits;
2842 	}
2843 
2844 	/*
2845 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2846 	 * by one fs block, so ee_len can cover the extent of maximum file
2847 	 * size
2848 	 */
2849 	res = (1LL << 32) - 1;
2850 	res <<= blkbits;
2851 
2852 	/* Sanity check against vm- & vfs- imposed limits */
2853 	if (res > upper_limit)
2854 		res = upper_limit;
2855 
2856 	return res;
2857 }
2858 
2859 /*
2860  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2861  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2862  * We need to be 1 filesystem block less than the 2^48 sector limit.
2863  */
2864 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2865 {
2866 	loff_t res = EXT4_NDIR_BLOCKS;
2867 	int meta_blocks;
2868 	loff_t upper_limit;
2869 	/* This is calculated to be the largest file size for a dense, block
2870 	 * mapped file such that the file's total number of 512-byte sectors,
2871 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2872 	 *
2873 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2874 	 * number of 512-byte sectors of the file.
2875 	 */
2876 
2877 	if (!has_huge_files) {
2878 		/*
2879 		 * !has_huge_files or implies that the inode i_block field
2880 		 * represents total file blocks in 2^32 512-byte sectors ==
2881 		 * size of vfs inode i_blocks * 8
2882 		 */
2883 		upper_limit = (1LL << 32) - 1;
2884 
2885 		/* total blocks in file system block size */
2886 		upper_limit >>= (bits - 9);
2887 
2888 	} else {
2889 		/*
2890 		 * We use 48 bit ext4_inode i_blocks
2891 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2892 		 * represent total number of blocks in
2893 		 * file system block size
2894 		 */
2895 		upper_limit = (1LL << 48) - 1;
2896 
2897 	}
2898 
2899 	/* indirect blocks */
2900 	meta_blocks = 1;
2901 	/* double indirect blocks */
2902 	meta_blocks += 1 + (1LL << (bits-2));
2903 	/* tripple indirect blocks */
2904 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2905 
2906 	upper_limit -= meta_blocks;
2907 	upper_limit <<= bits;
2908 
2909 	res += 1LL << (bits-2);
2910 	res += 1LL << (2*(bits-2));
2911 	res += 1LL << (3*(bits-2));
2912 	res <<= bits;
2913 	if (res > upper_limit)
2914 		res = upper_limit;
2915 
2916 	if (res > MAX_LFS_FILESIZE)
2917 		res = MAX_LFS_FILESIZE;
2918 
2919 	return res;
2920 }
2921 
2922 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2923 				   ext4_fsblk_t logical_sb_block, int nr)
2924 {
2925 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2926 	ext4_group_t bg, first_meta_bg;
2927 	int has_super = 0;
2928 
2929 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2930 
2931 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2932 		return logical_sb_block + nr + 1;
2933 	bg = sbi->s_desc_per_block * nr;
2934 	if (ext4_bg_has_super(sb, bg))
2935 		has_super = 1;
2936 
2937 	/*
2938 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2939 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2940 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2941 	 * compensate.
2942 	 */
2943 	if (sb->s_blocksize == 1024 && nr == 0 &&
2944 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2945 		has_super++;
2946 
2947 	return (has_super + ext4_group_first_block_no(sb, bg));
2948 }
2949 
2950 /**
2951  * ext4_get_stripe_size: Get the stripe size.
2952  * @sbi: In memory super block info
2953  *
2954  * If we have specified it via mount option, then
2955  * use the mount option value. If the value specified at mount time is
2956  * greater than the blocks per group use the super block value.
2957  * If the super block value is greater than blocks per group return 0.
2958  * Allocator needs it be less than blocks per group.
2959  *
2960  */
2961 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2962 {
2963 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2964 	unsigned long stripe_width =
2965 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2966 	int ret;
2967 
2968 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2969 		ret = sbi->s_stripe;
2970 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2971 		ret = stripe_width;
2972 	else if (stride && stride <= sbi->s_blocks_per_group)
2973 		ret = stride;
2974 	else
2975 		ret = 0;
2976 
2977 	/*
2978 	 * If the stripe width is 1, this makes no sense and
2979 	 * we set it to 0 to turn off stripe handling code.
2980 	 */
2981 	if (ret <= 1)
2982 		ret = 0;
2983 
2984 	return ret;
2985 }
2986 
2987 /*
2988  * Check whether this filesystem can be mounted based on
2989  * the features present and the RDONLY/RDWR mount requested.
2990  * Returns 1 if this filesystem can be mounted as requested,
2991  * 0 if it cannot be.
2992  */
2993 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2994 {
2995 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2996 		ext4_msg(sb, KERN_ERR,
2997 			"Couldn't mount because of "
2998 			"unsupported optional features (%x)",
2999 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
3000 			~EXT4_FEATURE_INCOMPAT_SUPP));
3001 		return 0;
3002 	}
3003 
3004 #ifndef CONFIG_UNICODE
3005 	if (ext4_has_feature_casefold(sb)) {
3006 		ext4_msg(sb, KERN_ERR,
3007 			 "Filesystem with casefold feature cannot be "
3008 			 "mounted without CONFIG_UNICODE");
3009 		return 0;
3010 	}
3011 #endif
3012 
3013 	if (readonly)
3014 		return 1;
3015 
3016 	if (ext4_has_feature_readonly(sb)) {
3017 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
3018 		sb->s_flags |= SB_RDONLY;
3019 		return 1;
3020 	}
3021 
3022 	/* Check that feature set is OK for a read-write mount */
3023 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
3024 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
3025 			 "unsupported optional features (%x)",
3026 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
3027 				~EXT4_FEATURE_RO_COMPAT_SUPP));
3028 		return 0;
3029 	}
3030 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
3031 		ext4_msg(sb, KERN_ERR,
3032 			 "Can't support bigalloc feature without "
3033 			 "extents feature\n");
3034 		return 0;
3035 	}
3036 
3037 #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2)
3038 	if (!readonly && (ext4_has_feature_quota(sb) ||
3039 			  ext4_has_feature_project(sb))) {
3040 		ext4_msg(sb, KERN_ERR,
3041 			 "The kernel was not built with CONFIG_QUOTA and CONFIG_QFMT_V2");
3042 		return 0;
3043 	}
3044 #endif  /* CONFIG_QUOTA */
3045 	return 1;
3046 }
3047 
3048 /*
3049  * This function is called once a day if we have errors logged
3050  * on the file system
3051  */
3052 static void print_daily_error_info(struct timer_list *t)
3053 {
3054 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
3055 	struct super_block *sb = sbi->s_sb;
3056 	struct ext4_super_block *es = sbi->s_es;
3057 
3058 	if (es->s_error_count)
3059 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3060 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3061 			 le32_to_cpu(es->s_error_count));
3062 	if (es->s_first_error_time) {
3063 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3064 		       sb->s_id,
3065 		       ext4_get_tstamp(es, s_first_error_time),
3066 		       (int) sizeof(es->s_first_error_func),
3067 		       es->s_first_error_func,
3068 		       le32_to_cpu(es->s_first_error_line));
3069 		if (es->s_first_error_ino)
3070 			printk(KERN_CONT ": inode %u",
3071 			       le32_to_cpu(es->s_first_error_ino));
3072 		if (es->s_first_error_block)
3073 			printk(KERN_CONT ": block %llu", (unsigned long long)
3074 			       le64_to_cpu(es->s_first_error_block));
3075 		printk(KERN_CONT "\n");
3076 	}
3077 	if (es->s_last_error_time) {
3078 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3079 		       sb->s_id,
3080 		       ext4_get_tstamp(es, s_last_error_time),
3081 		       (int) sizeof(es->s_last_error_func),
3082 		       es->s_last_error_func,
3083 		       le32_to_cpu(es->s_last_error_line));
3084 		if (es->s_last_error_ino)
3085 			printk(KERN_CONT ": inode %u",
3086 			       le32_to_cpu(es->s_last_error_ino));
3087 		if (es->s_last_error_block)
3088 			printk(KERN_CONT ": block %llu", (unsigned long long)
3089 			       le64_to_cpu(es->s_last_error_block));
3090 		printk(KERN_CONT "\n");
3091 	}
3092 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3093 }
3094 
3095 /* Find next suitable group and run ext4_init_inode_table */
3096 static int ext4_run_li_request(struct ext4_li_request *elr)
3097 {
3098 	struct ext4_group_desc *gdp = NULL;
3099 	ext4_group_t group, ngroups;
3100 	struct super_block *sb;
3101 	unsigned long timeout = 0;
3102 	int ret = 0;
3103 
3104 	sb = elr->lr_super;
3105 	ngroups = EXT4_SB(sb)->s_groups_count;
3106 
3107 	for (group = elr->lr_next_group; group < ngroups; group++) {
3108 		gdp = ext4_get_group_desc(sb, group, NULL);
3109 		if (!gdp) {
3110 			ret = 1;
3111 			break;
3112 		}
3113 
3114 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3115 			break;
3116 	}
3117 
3118 	if (group >= ngroups)
3119 		ret = 1;
3120 
3121 	if (!ret) {
3122 		timeout = jiffies;
3123 		ret = ext4_init_inode_table(sb, group,
3124 					    elr->lr_timeout ? 0 : 1);
3125 		if (elr->lr_timeout == 0) {
3126 			timeout = (jiffies - timeout) *
3127 				  elr->lr_sbi->s_li_wait_mult;
3128 			elr->lr_timeout = timeout;
3129 		}
3130 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3131 		elr->lr_next_group = group + 1;
3132 	}
3133 	return ret;
3134 }
3135 
3136 /*
3137  * Remove lr_request from the list_request and free the
3138  * request structure. Should be called with li_list_mtx held
3139  */
3140 static void ext4_remove_li_request(struct ext4_li_request *elr)
3141 {
3142 	struct ext4_sb_info *sbi;
3143 
3144 	if (!elr)
3145 		return;
3146 
3147 	sbi = elr->lr_sbi;
3148 
3149 	list_del(&elr->lr_request);
3150 	sbi->s_li_request = NULL;
3151 	kfree(elr);
3152 }
3153 
3154 static void ext4_unregister_li_request(struct super_block *sb)
3155 {
3156 	mutex_lock(&ext4_li_mtx);
3157 	if (!ext4_li_info) {
3158 		mutex_unlock(&ext4_li_mtx);
3159 		return;
3160 	}
3161 
3162 	mutex_lock(&ext4_li_info->li_list_mtx);
3163 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3164 	mutex_unlock(&ext4_li_info->li_list_mtx);
3165 	mutex_unlock(&ext4_li_mtx);
3166 }
3167 
3168 static struct task_struct *ext4_lazyinit_task;
3169 
3170 /*
3171  * This is the function where ext4lazyinit thread lives. It walks
3172  * through the request list searching for next scheduled filesystem.
3173  * When such a fs is found, run the lazy initialization request
3174  * (ext4_rn_li_request) and keep track of the time spend in this
3175  * function. Based on that time we compute next schedule time of
3176  * the request. When walking through the list is complete, compute
3177  * next waking time and put itself into sleep.
3178  */
3179 static int ext4_lazyinit_thread(void *arg)
3180 {
3181 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3182 	struct list_head *pos, *n;
3183 	struct ext4_li_request *elr;
3184 	unsigned long next_wakeup, cur;
3185 
3186 	BUG_ON(NULL == eli);
3187 
3188 cont_thread:
3189 	while (true) {
3190 		next_wakeup = MAX_JIFFY_OFFSET;
3191 
3192 		mutex_lock(&eli->li_list_mtx);
3193 		if (list_empty(&eli->li_request_list)) {
3194 			mutex_unlock(&eli->li_list_mtx);
3195 			goto exit_thread;
3196 		}
3197 		list_for_each_safe(pos, n, &eli->li_request_list) {
3198 			int err = 0;
3199 			int progress = 0;
3200 			elr = list_entry(pos, struct ext4_li_request,
3201 					 lr_request);
3202 
3203 			if (time_before(jiffies, elr->lr_next_sched)) {
3204 				if (time_before(elr->lr_next_sched, next_wakeup))
3205 					next_wakeup = elr->lr_next_sched;
3206 				continue;
3207 			}
3208 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3209 				if (sb_start_write_trylock(elr->lr_super)) {
3210 					progress = 1;
3211 					/*
3212 					 * We hold sb->s_umount, sb can not
3213 					 * be removed from the list, it is
3214 					 * now safe to drop li_list_mtx
3215 					 */
3216 					mutex_unlock(&eli->li_list_mtx);
3217 					err = ext4_run_li_request(elr);
3218 					sb_end_write(elr->lr_super);
3219 					mutex_lock(&eli->li_list_mtx);
3220 					n = pos->next;
3221 				}
3222 				up_read((&elr->lr_super->s_umount));
3223 			}
3224 			/* error, remove the lazy_init job */
3225 			if (err) {
3226 				ext4_remove_li_request(elr);
3227 				continue;
3228 			}
3229 			if (!progress) {
3230 				elr->lr_next_sched = jiffies +
3231 					(prandom_u32()
3232 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3233 			}
3234 			if (time_before(elr->lr_next_sched, next_wakeup))
3235 				next_wakeup = elr->lr_next_sched;
3236 		}
3237 		mutex_unlock(&eli->li_list_mtx);
3238 
3239 		try_to_freeze();
3240 
3241 		cur = jiffies;
3242 		if ((time_after_eq(cur, next_wakeup)) ||
3243 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3244 			cond_resched();
3245 			continue;
3246 		}
3247 
3248 		schedule_timeout_interruptible(next_wakeup - cur);
3249 
3250 		if (kthread_should_stop()) {
3251 			ext4_clear_request_list();
3252 			goto exit_thread;
3253 		}
3254 	}
3255 
3256 exit_thread:
3257 	/*
3258 	 * It looks like the request list is empty, but we need
3259 	 * to check it under the li_list_mtx lock, to prevent any
3260 	 * additions into it, and of course we should lock ext4_li_mtx
3261 	 * to atomically free the list and ext4_li_info, because at
3262 	 * this point another ext4 filesystem could be registering
3263 	 * new one.
3264 	 */
3265 	mutex_lock(&ext4_li_mtx);
3266 	mutex_lock(&eli->li_list_mtx);
3267 	if (!list_empty(&eli->li_request_list)) {
3268 		mutex_unlock(&eli->li_list_mtx);
3269 		mutex_unlock(&ext4_li_mtx);
3270 		goto cont_thread;
3271 	}
3272 	mutex_unlock(&eli->li_list_mtx);
3273 	kfree(ext4_li_info);
3274 	ext4_li_info = NULL;
3275 	mutex_unlock(&ext4_li_mtx);
3276 
3277 	return 0;
3278 }
3279 
3280 static void ext4_clear_request_list(void)
3281 {
3282 	struct list_head *pos, *n;
3283 	struct ext4_li_request *elr;
3284 
3285 	mutex_lock(&ext4_li_info->li_list_mtx);
3286 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3287 		elr = list_entry(pos, struct ext4_li_request,
3288 				 lr_request);
3289 		ext4_remove_li_request(elr);
3290 	}
3291 	mutex_unlock(&ext4_li_info->li_list_mtx);
3292 }
3293 
3294 static int ext4_run_lazyinit_thread(void)
3295 {
3296 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3297 					 ext4_li_info, "ext4lazyinit");
3298 	if (IS_ERR(ext4_lazyinit_task)) {
3299 		int err = PTR_ERR(ext4_lazyinit_task);
3300 		ext4_clear_request_list();
3301 		kfree(ext4_li_info);
3302 		ext4_li_info = NULL;
3303 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3304 				 "initialization thread\n",
3305 				 err);
3306 		return err;
3307 	}
3308 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3309 	return 0;
3310 }
3311 
3312 /*
3313  * Check whether it make sense to run itable init. thread or not.
3314  * If there is at least one uninitialized inode table, return
3315  * corresponding group number, else the loop goes through all
3316  * groups and return total number of groups.
3317  */
3318 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3319 {
3320 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3321 	struct ext4_group_desc *gdp = NULL;
3322 
3323 	if (!ext4_has_group_desc_csum(sb))
3324 		return ngroups;
3325 
3326 	for (group = 0; group < ngroups; group++) {
3327 		gdp = ext4_get_group_desc(sb, group, NULL);
3328 		if (!gdp)
3329 			continue;
3330 
3331 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3332 			break;
3333 	}
3334 
3335 	return group;
3336 }
3337 
3338 static int ext4_li_info_new(void)
3339 {
3340 	struct ext4_lazy_init *eli = NULL;
3341 
3342 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3343 	if (!eli)
3344 		return -ENOMEM;
3345 
3346 	INIT_LIST_HEAD(&eli->li_request_list);
3347 	mutex_init(&eli->li_list_mtx);
3348 
3349 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3350 
3351 	ext4_li_info = eli;
3352 
3353 	return 0;
3354 }
3355 
3356 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3357 					    ext4_group_t start)
3358 {
3359 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3360 	struct ext4_li_request *elr;
3361 
3362 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3363 	if (!elr)
3364 		return NULL;
3365 
3366 	elr->lr_super = sb;
3367 	elr->lr_sbi = sbi;
3368 	elr->lr_next_group = start;
3369 
3370 	/*
3371 	 * Randomize first schedule time of the request to
3372 	 * spread the inode table initialization requests
3373 	 * better.
3374 	 */
3375 	elr->lr_next_sched = jiffies + (prandom_u32() %
3376 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3377 	return elr;
3378 }
3379 
3380 int ext4_register_li_request(struct super_block *sb,
3381 			     ext4_group_t first_not_zeroed)
3382 {
3383 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3384 	struct ext4_li_request *elr = NULL;
3385 	ext4_group_t ngroups = sbi->s_groups_count;
3386 	int ret = 0;
3387 
3388 	mutex_lock(&ext4_li_mtx);
3389 	if (sbi->s_li_request != NULL) {
3390 		/*
3391 		 * Reset timeout so it can be computed again, because
3392 		 * s_li_wait_mult might have changed.
3393 		 */
3394 		sbi->s_li_request->lr_timeout = 0;
3395 		goto out;
3396 	}
3397 
3398 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3399 	    !test_opt(sb, INIT_INODE_TABLE))
3400 		goto out;
3401 
3402 	elr = ext4_li_request_new(sb, first_not_zeroed);
3403 	if (!elr) {
3404 		ret = -ENOMEM;
3405 		goto out;
3406 	}
3407 
3408 	if (NULL == ext4_li_info) {
3409 		ret = ext4_li_info_new();
3410 		if (ret)
3411 			goto out;
3412 	}
3413 
3414 	mutex_lock(&ext4_li_info->li_list_mtx);
3415 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3416 	mutex_unlock(&ext4_li_info->li_list_mtx);
3417 
3418 	sbi->s_li_request = elr;
3419 	/*
3420 	 * set elr to NULL here since it has been inserted to
3421 	 * the request_list and the removal and free of it is
3422 	 * handled by ext4_clear_request_list from now on.
3423 	 */
3424 	elr = NULL;
3425 
3426 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3427 		ret = ext4_run_lazyinit_thread();
3428 		if (ret)
3429 			goto out;
3430 	}
3431 out:
3432 	mutex_unlock(&ext4_li_mtx);
3433 	if (ret)
3434 		kfree(elr);
3435 	return ret;
3436 }
3437 
3438 /*
3439  * We do not need to lock anything since this is called on
3440  * module unload.
3441  */
3442 static void ext4_destroy_lazyinit_thread(void)
3443 {
3444 	/*
3445 	 * If thread exited earlier
3446 	 * there's nothing to be done.
3447 	 */
3448 	if (!ext4_li_info || !ext4_lazyinit_task)
3449 		return;
3450 
3451 	kthread_stop(ext4_lazyinit_task);
3452 }
3453 
3454 static int set_journal_csum_feature_set(struct super_block *sb)
3455 {
3456 	int ret = 1;
3457 	int compat, incompat;
3458 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3459 
3460 	if (ext4_has_metadata_csum(sb)) {
3461 		/* journal checksum v3 */
3462 		compat = 0;
3463 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3464 	} else {
3465 		/* journal checksum v1 */
3466 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3467 		incompat = 0;
3468 	}
3469 
3470 	jbd2_journal_clear_features(sbi->s_journal,
3471 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3472 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3473 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3474 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3475 		ret = jbd2_journal_set_features(sbi->s_journal,
3476 				compat, 0,
3477 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3478 				incompat);
3479 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3480 		ret = jbd2_journal_set_features(sbi->s_journal,
3481 				compat, 0,
3482 				incompat);
3483 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3484 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3485 	} else {
3486 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3487 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3488 	}
3489 
3490 	return ret;
3491 }
3492 
3493 /*
3494  * Note: calculating the overhead so we can be compatible with
3495  * historical BSD practice is quite difficult in the face of
3496  * clusters/bigalloc.  This is because multiple metadata blocks from
3497  * different block group can end up in the same allocation cluster.
3498  * Calculating the exact overhead in the face of clustered allocation
3499  * requires either O(all block bitmaps) in memory or O(number of block
3500  * groups**2) in time.  We will still calculate the superblock for
3501  * older file systems --- and if we come across with a bigalloc file
3502  * system with zero in s_overhead_clusters the estimate will be close to
3503  * correct especially for very large cluster sizes --- but for newer
3504  * file systems, it's better to calculate this figure once at mkfs
3505  * time, and store it in the superblock.  If the superblock value is
3506  * present (even for non-bigalloc file systems), we will use it.
3507  */
3508 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3509 			  char *buf)
3510 {
3511 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3512 	struct ext4_group_desc	*gdp;
3513 	ext4_fsblk_t		first_block, last_block, b;
3514 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3515 	int			s, j, count = 0;
3516 
3517 	if (!ext4_has_feature_bigalloc(sb))
3518 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3519 			sbi->s_itb_per_group + 2);
3520 
3521 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3522 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3523 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3524 	for (i = 0; i < ngroups; i++) {
3525 		gdp = ext4_get_group_desc(sb, i, NULL);
3526 		b = ext4_block_bitmap(sb, gdp);
3527 		if (b >= first_block && b <= last_block) {
3528 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3529 			count++;
3530 		}
3531 		b = ext4_inode_bitmap(sb, gdp);
3532 		if (b >= first_block && b <= last_block) {
3533 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3534 			count++;
3535 		}
3536 		b = ext4_inode_table(sb, gdp);
3537 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3538 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3539 				int c = EXT4_B2C(sbi, b - first_block);
3540 				ext4_set_bit(c, buf);
3541 				count++;
3542 			}
3543 		if (i != grp)
3544 			continue;
3545 		s = 0;
3546 		if (ext4_bg_has_super(sb, grp)) {
3547 			ext4_set_bit(s++, buf);
3548 			count++;
3549 		}
3550 		j = ext4_bg_num_gdb(sb, grp);
3551 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3552 			ext4_error(sb, "Invalid number of block group "
3553 				   "descriptor blocks: %d", j);
3554 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3555 		}
3556 		count += j;
3557 		for (; j > 0; j--)
3558 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3559 	}
3560 	if (!count)
3561 		return 0;
3562 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3563 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3564 }
3565 
3566 /*
3567  * Compute the overhead and stash it in sbi->s_overhead
3568  */
3569 int ext4_calculate_overhead(struct super_block *sb)
3570 {
3571 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3572 	struct ext4_super_block *es = sbi->s_es;
3573 	struct inode *j_inode;
3574 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3575 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3576 	ext4_fsblk_t overhead = 0;
3577 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3578 
3579 	if (!buf)
3580 		return -ENOMEM;
3581 
3582 	/*
3583 	 * Compute the overhead (FS structures).  This is constant
3584 	 * for a given filesystem unless the number of block groups
3585 	 * changes so we cache the previous value until it does.
3586 	 */
3587 
3588 	/*
3589 	 * All of the blocks before first_data_block are overhead
3590 	 */
3591 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3592 
3593 	/*
3594 	 * Add the overhead found in each block group
3595 	 */
3596 	for (i = 0; i < ngroups; i++) {
3597 		int blks;
3598 
3599 		blks = count_overhead(sb, i, buf);
3600 		overhead += blks;
3601 		if (blks)
3602 			memset(buf, 0, PAGE_SIZE);
3603 		cond_resched();
3604 	}
3605 
3606 	/*
3607 	 * Add the internal journal blocks whether the journal has been
3608 	 * loaded or not
3609 	 */
3610 	if (sbi->s_journal && !sbi->journal_bdev)
3611 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3612 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3613 		j_inode = ext4_get_journal_inode(sb, j_inum);
3614 		if (j_inode) {
3615 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3616 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3617 			iput(j_inode);
3618 		} else {
3619 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3620 		}
3621 	}
3622 	sbi->s_overhead = overhead;
3623 	smp_wmb();
3624 	free_page((unsigned long) buf);
3625 	return 0;
3626 }
3627 
3628 static void ext4_set_resv_clusters(struct super_block *sb)
3629 {
3630 	ext4_fsblk_t resv_clusters;
3631 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3632 
3633 	/*
3634 	 * There's no need to reserve anything when we aren't using extents.
3635 	 * The space estimates are exact, there are no unwritten extents,
3636 	 * hole punching doesn't need new metadata... This is needed especially
3637 	 * to keep ext2/3 backward compatibility.
3638 	 */
3639 	if (!ext4_has_feature_extents(sb))
3640 		return;
3641 	/*
3642 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3643 	 * This should cover the situations where we can not afford to run
3644 	 * out of space like for example punch hole, or converting
3645 	 * unwritten extents in delalloc path. In most cases such
3646 	 * allocation would require 1, or 2 blocks, higher numbers are
3647 	 * very rare.
3648 	 */
3649 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3650 			 sbi->s_cluster_bits);
3651 
3652 	do_div(resv_clusters, 50);
3653 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3654 
3655 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3656 }
3657 
3658 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3659 {
3660 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3661 	char *orig_data = kstrdup(data, GFP_KERNEL);
3662 	struct buffer_head *bh, **group_desc;
3663 	struct ext4_super_block *es = NULL;
3664 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3665 	struct flex_groups **flex_groups;
3666 	ext4_fsblk_t block;
3667 	ext4_fsblk_t sb_block = get_sb_block(&data);
3668 	ext4_fsblk_t logical_sb_block;
3669 	unsigned long offset = 0;
3670 	unsigned long journal_devnum = 0;
3671 	unsigned long def_mount_opts;
3672 	struct inode *root;
3673 	const char *descr;
3674 	int ret = -ENOMEM;
3675 	int blocksize, clustersize;
3676 	unsigned int db_count;
3677 	unsigned int i;
3678 	int needs_recovery, has_huge_files, has_bigalloc;
3679 	__u64 blocks_count;
3680 	int err = 0;
3681 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3682 	ext4_group_t first_not_zeroed;
3683 
3684 	if ((data && !orig_data) || !sbi)
3685 		goto out_free_base;
3686 
3687 	sbi->s_daxdev = dax_dev;
3688 	sbi->s_blockgroup_lock =
3689 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3690 	if (!sbi->s_blockgroup_lock)
3691 		goto out_free_base;
3692 
3693 	sb->s_fs_info = sbi;
3694 	sbi->s_sb = sb;
3695 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3696 	sbi->s_sb_block = sb_block;
3697 	if (sb->s_bdev->bd_part)
3698 		sbi->s_sectors_written_start =
3699 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3700 
3701 	/* Cleanup superblock name */
3702 	strreplace(sb->s_id, '/', '!');
3703 
3704 	/* -EINVAL is default */
3705 	ret = -EINVAL;
3706 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3707 	if (!blocksize) {
3708 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3709 		goto out_fail;
3710 	}
3711 
3712 	/*
3713 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3714 	 * block sizes.  We need to calculate the offset from buffer start.
3715 	 */
3716 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3717 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3718 		offset = do_div(logical_sb_block, blocksize);
3719 	} else {
3720 		logical_sb_block = sb_block;
3721 	}
3722 
3723 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3724 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3725 		goto out_fail;
3726 	}
3727 	/*
3728 	 * Note: s_es must be initialized as soon as possible because
3729 	 *       some ext4 macro-instructions depend on its value
3730 	 */
3731 	es = (struct ext4_super_block *) (bh->b_data + offset);
3732 	sbi->s_es = es;
3733 	sb->s_magic = le16_to_cpu(es->s_magic);
3734 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3735 		goto cantfind_ext4;
3736 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3737 
3738 	/* Warn if metadata_csum and gdt_csum are both set. */
3739 	if (ext4_has_feature_metadata_csum(sb) &&
3740 	    ext4_has_feature_gdt_csum(sb))
3741 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3742 			     "redundant flags; please run fsck.");
3743 
3744 	/* Check for a known checksum algorithm */
3745 	if (!ext4_verify_csum_type(sb, es)) {
3746 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3747 			 "unknown checksum algorithm.");
3748 		silent = 1;
3749 		goto cantfind_ext4;
3750 	}
3751 
3752 	/* Load the checksum driver */
3753 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3754 	if (IS_ERR(sbi->s_chksum_driver)) {
3755 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3756 		ret = PTR_ERR(sbi->s_chksum_driver);
3757 		sbi->s_chksum_driver = NULL;
3758 		goto failed_mount;
3759 	}
3760 
3761 	/* Check superblock checksum */
3762 	if (!ext4_superblock_csum_verify(sb, es)) {
3763 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3764 			 "invalid superblock checksum.  Run e2fsck?");
3765 		silent = 1;
3766 		ret = -EFSBADCRC;
3767 		goto cantfind_ext4;
3768 	}
3769 
3770 	/* Precompute checksum seed for all metadata */
3771 	if (ext4_has_feature_csum_seed(sb))
3772 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3773 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3774 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3775 					       sizeof(es->s_uuid));
3776 
3777 	/* Set defaults before we parse the mount options */
3778 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3779 	set_opt(sb, INIT_INODE_TABLE);
3780 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3781 		set_opt(sb, DEBUG);
3782 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3783 		set_opt(sb, GRPID);
3784 	if (def_mount_opts & EXT4_DEFM_UID16)
3785 		set_opt(sb, NO_UID32);
3786 	/* xattr user namespace & acls are now defaulted on */
3787 	set_opt(sb, XATTR_USER);
3788 	set_opt(sb, DIOREAD_NOLOCK);
3789 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3790 	set_opt(sb, POSIX_ACL);
3791 #endif
3792 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3793 	if (ext4_has_metadata_csum(sb))
3794 		set_opt(sb, JOURNAL_CHECKSUM);
3795 
3796 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3797 		set_opt(sb, JOURNAL_DATA);
3798 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3799 		set_opt(sb, ORDERED_DATA);
3800 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3801 		set_opt(sb, WRITEBACK_DATA);
3802 
3803 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3804 		set_opt(sb, ERRORS_PANIC);
3805 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3806 		set_opt(sb, ERRORS_CONT);
3807 	else
3808 		set_opt(sb, ERRORS_RO);
3809 	/* block_validity enabled by default; disable with noblock_validity */
3810 	set_opt(sb, BLOCK_VALIDITY);
3811 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3812 		set_opt(sb, DISCARD);
3813 
3814 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3815 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3816 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3817 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3818 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3819 
3820 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3821 		set_opt(sb, BARRIER);
3822 
3823 	/*
3824 	 * enable delayed allocation by default
3825 	 * Use -o nodelalloc to turn it off
3826 	 */
3827 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3828 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3829 		set_opt(sb, DELALLOC);
3830 
3831 	/*
3832 	 * set default s_li_wait_mult for lazyinit, for the case there is
3833 	 * no mount option specified.
3834 	 */
3835 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3836 
3837 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3838 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3839 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3840 		ext4_msg(sb, KERN_ERR,
3841 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3842 			 blocksize, le32_to_cpu(es->s_log_block_size));
3843 		goto failed_mount;
3844 	}
3845 
3846 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3847 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3848 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3849 	} else {
3850 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3851 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3852 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3853 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3854 				 sbi->s_first_ino);
3855 			goto failed_mount;
3856 		}
3857 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3858 		    (!is_power_of_2(sbi->s_inode_size)) ||
3859 		    (sbi->s_inode_size > blocksize)) {
3860 			ext4_msg(sb, KERN_ERR,
3861 			       "unsupported inode size: %d",
3862 			       sbi->s_inode_size);
3863 			ext4_msg(sb, KERN_ERR, "blocksize: %d", blocksize);
3864 			goto failed_mount;
3865 		}
3866 		/*
3867 		 * i_atime_extra is the last extra field available for
3868 		 * [acm]times in struct ext4_inode. Checking for that
3869 		 * field should suffice to ensure we have extra space
3870 		 * for all three.
3871 		 */
3872 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
3873 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
3874 			sb->s_time_gran = 1;
3875 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
3876 		} else {
3877 			sb->s_time_gran = NSEC_PER_SEC;
3878 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
3879 		}
3880 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
3881 	}
3882 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3883 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3884 			EXT4_GOOD_OLD_INODE_SIZE;
3885 		if (ext4_has_feature_extra_isize(sb)) {
3886 			unsigned v, max = (sbi->s_inode_size -
3887 					   EXT4_GOOD_OLD_INODE_SIZE);
3888 
3889 			v = le16_to_cpu(es->s_want_extra_isize);
3890 			if (v > max) {
3891 				ext4_msg(sb, KERN_ERR,
3892 					 "bad s_want_extra_isize: %d", v);
3893 				goto failed_mount;
3894 			}
3895 			if (sbi->s_want_extra_isize < v)
3896 				sbi->s_want_extra_isize = v;
3897 
3898 			v = le16_to_cpu(es->s_min_extra_isize);
3899 			if (v > max) {
3900 				ext4_msg(sb, KERN_ERR,
3901 					 "bad s_min_extra_isize: %d", v);
3902 				goto failed_mount;
3903 			}
3904 			if (sbi->s_want_extra_isize < v)
3905 				sbi->s_want_extra_isize = v;
3906 		}
3907 	}
3908 
3909 	if (sbi->s_es->s_mount_opts[0]) {
3910 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3911 					      sizeof(sbi->s_es->s_mount_opts),
3912 					      GFP_KERNEL);
3913 		if (!s_mount_opts)
3914 			goto failed_mount;
3915 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3916 				   &journal_ioprio, 0)) {
3917 			ext4_msg(sb, KERN_WARNING,
3918 				 "failed to parse options in superblock: %s",
3919 				 s_mount_opts);
3920 		}
3921 		kfree(s_mount_opts);
3922 	}
3923 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3924 	if (!parse_options((char *) data, sb, &journal_devnum,
3925 			   &journal_ioprio, 0))
3926 		goto failed_mount;
3927 
3928 #ifdef CONFIG_UNICODE
3929 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3930 		const struct ext4_sb_encodings *encoding_info;
3931 		struct unicode_map *encoding;
3932 		__u16 encoding_flags;
3933 
3934 		if (ext4_has_feature_encrypt(sb)) {
3935 			ext4_msg(sb, KERN_ERR,
3936 				 "Can't mount with encoding and encryption");
3937 			goto failed_mount;
3938 		}
3939 
3940 		if (ext4_sb_read_encoding(es, &encoding_info,
3941 					  &encoding_flags)) {
3942 			ext4_msg(sb, KERN_ERR,
3943 				 "Encoding requested by superblock is unknown");
3944 			goto failed_mount;
3945 		}
3946 
3947 		encoding = utf8_load(encoding_info->version);
3948 		if (IS_ERR(encoding)) {
3949 			ext4_msg(sb, KERN_ERR,
3950 				 "can't mount with superblock charset: %s-%s "
3951 				 "not supported by the kernel. flags: 0x%x.",
3952 				 encoding_info->name, encoding_info->version,
3953 				 encoding_flags);
3954 			goto failed_mount;
3955 		}
3956 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3957 			 "%s-%s with flags 0x%hx", encoding_info->name,
3958 			 encoding_info->version?:"\b", encoding_flags);
3959 
3960 		sbi->s_encoding = encoding;
3961 		sbi->s_encoding_flags = encoding_flags;
3962 	}
3963 #endif
3964 
3965 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3966 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, and O_DIRECT support!\n");
3967 		clear_opt(sb, DIOREAD_NOLOCK);
3968 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3969 			ext4_msg(sb, KERN_ERR, "can't mount with "
3970 				 "both data=journal and delalloc");
3971 			goto failed_mount;
3972 		}
3973 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3974 			ext4_msg(sb, KERN_ERR, "can't mount with "
3975 				 "both data=journal and dioread_nolock");
3976 			goto failed_mount;
3977 		}
3978 		if (test_opt(sb, DAX)) {
3979 			ext4_msg(sb, KERN_ERR, "can't mount with "
3980 				 "both data=journal and dax");
3981 			goto failed_mount;
3982 		}
3983 		if (ext4_has_feature_encrypt(sb)) {
3984 			ext4_msg(sb, KERN_WARNING,
3985 				 "encrypted files will use data=ordered "
3986 				 "instead of data journaling mode");
3987 		}
3988 		if (test_opt(sb, DELALLOC))
3989 			clear_opt(sb, DELALLOC);
3990 	} else {
3991 		sb->s_iflags |= SB_I_CGROUPWB;
3992 	}
3993 
3994 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3995 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3996 
3997 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3998 	    (ext4_has_compat_features(sb) ||
3999 	     ext4_has_ro_compat_features(sb) ||
4000 	     ext4_has_incompat_features(sb)))
4001 		ext4_msg(sb, KERN_WARNING,
4002 		       "feature flags set on rev 0 fs, "
4003 		       "running e2fsck is recommended");
4004 
4005 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
4006 		set_opt2(sb, HURD_COMPAT);
4007 		if (ext4_has_feature_64bit(sb)) {
4008 			ext4_msg(sb, KERN_ERR,
4009 				 "The Hurd can't support 64-bit file systems");
4010 			goto failed_mount;
4011 		}
4012 
4013 		/*
4014 		 * ea_inode feature uses l_i_version field which is not
4015 		 * available in HURD_COMPAT mode.
4016 		 */
4017 		if (ext4_has_feature_ea_inode(sb)) {
4018 			ext4_msg(sb, KERN_ERR,
4019 				 "ea_inode feature is not supported for Hurd");
4020 			goto failed_mount;
4021 		}
4022 	}
4023 
4024 	if (IS_EXT2_SB(sb)) {
4025 		if (ext2_feature_set_ok(sb))
4026 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
4027 				 "using the ext4 subsystem");
4028 		else {
4029 			/*
4030 			 * If we're probing be silent, if this looks like
4031 			 * it's actually an ext[34] filesystem.
4032 			 */
4033 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4034 				goto failed_mount;
4035 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
4036 				 "to feature incompatibilities");
4037 			goto failed_mount;
4038 		}
4039 	}
4040 
4041 	if (IS_EXT3_SB(sb)) {
4042 		if (ext3_feature_set_ok(sb))
4043 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
4044 				 "using the ext4 subsystem");
4045 		else {
4046 			/*
4047 			 * If we're probing be silent, if this looks like
4048 			 * it's actually an ext4 filesystem.
4049 			 */
4050 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
4051 				goto failed_mount;
4052 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
4053 				 "to feature incompatibilities");
4054 			goto failed_mount;
4055 		}
4056 	}
4057 
4058 	/*
4059 	 * Check feature flags regardless of the revision level, since we
4060 	 * previously didn't change the revision level when setting the flags,
4061 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
4062 	 */
4063 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
4064 		goto failed_mount;
4065 
4066 	if (le32_to_cpu(es->s_log_block_size) >
4067 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4068 		ext4_msg(sb, KERN_ERR,
4069 			 "Invalid log block size: %u",
4070 			 le32_to_cpu(es->s_log_block_size));
4071 		goto failed_mount;
4072 	}
4073 	if (le32_to_cpu(es->s_log_cluster_size) >
4074 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
4075 		ext4_msg(sb, KERN_ERR,
4076 			 "Invalid log cluster size: %u",
4077 			 le32_to_cpu(es->s_log_cluster_size));
4078 		goto failed_mount;
4079 	}
4080 
4081 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
4082 		ext4_msg(sb, KERN_ERR,
4083 			 "Number of reserved GDT blocks insanely large: %d",
4084 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
4085 		goto failed_mount;
4086 	}
4087 
4088 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
4089 		if (ext4_has_feature_inline_data(sb)) {
4090 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
4091 					" that may contain inline data");
4092 			goto failed_mount;
4093 		}
4094 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
4095 			ext4_msg(sb, KERN_ERR,
4096 				"DAX unsupported by block device.");
4097 			goto failed_mount;
4098 		}
4099 	}
4100 
4101 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4102 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4103 			 es->s_encryption_level);
4104 		goto failed_mount;
4105 	}
4106 
4107 	if (sb->s_blocksize != blocksize) {
4108 		/* Validate the filesystem blocksize */
4109 		if (!sb_set_blocksize(sb, blocksize)) {
4110 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4111 					blocksize);
4112 			goto failed_mount;
4113 		}
4114 
4115 		brelse(bh);
4116 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4117 		offset = do_div(logical_sb_block, blocksize);
4118 		bh = sb_bread_unmovable(sb, logical_sb_block);
4119 		if (!bh) {
4120 			ext4_msg(sb, KERN_ERR,
4121 			       "Can't read superblock on 2nd try");
4122 			goto failed_mount;
4123 		}
4124 		es = (struct ext4_super_block *)(bh->b_data + offset);
4125 		sbi->s_es = es;
4126 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4127 			ext4_msg(sb, KERN_ERR,
4128 			       "Magic mismatch, very weird!");
4129 			goto failed_mount;
4130 		}
4131 	}
4132 
4133 	has_huge_files = ext4_has_feature_huge_file(sb);
4134 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4135 						      has_huge_files);
4136 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4137 
4138 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4139 	if (ext4_has_feature_64bit(sb)) {
4140 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4141 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4142 		    !is_power_of_2(sbi->s_desc_size)) {
4143 			ext4_msg(sb, KERN_ERR,
4144 			       "unsupported descriptor size %lu",
4145 			       sbi->s_desc_size);
4146 			goto failed_mount;
4147 		}
4148 	} else
4149 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4150 
4151 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4152 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4153 
4154 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4155 	if (sbi->s_inodes_per_block == 0)
4156 		goto cantfind_ext4;
4157 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4158 	    sbi->s_inodes_per_group > blocksize * 8) {
4159 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4160 			 sbi->s_blocks_per_group);
4161 		goto failed_mount;
4162 	}
4163 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4164 					sbi->s_inodes_per_block;
4165 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4166 	sbi->s_sbh = bh;
4167 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4168 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4169 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4170 
4171 	for (i = 0; i < 4; i++)
4172 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4173 	sbi->s_def_hash_version = es->s_def_hash_version;
4174 	if (ext4_has_feature_dir_index(sb)) {
4175 		i = le32_to_cpu(es->s_flags);
4176 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4177 			sbi->s_hash_unsigned = 3;
4178 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4179 #ifdef __CHAR_UNSIGNED__
4180 			if (!sb_rdonly(sb))
4181 				es->s_flags |=
4182 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4183 			sbi->s_hash_unsigned = 3;
4184 #else
4185 			if (!sb_rdonly(sb))
4186 				es->s_flags |=
4187 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4188 #endif
4189 		}
4190 	}
4191 
4192 	/* Handle clustersize */
4193 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4194 	has_bigalloc = ext4_has_feature_bigalloc(sb);
4195 	if (has_bigalloc) {
4196 		if (clustersize < blocksize) {
4197 			ext4_msg(sb, KERN_ERR,
4198 				 "cluster size (%d) smaller than "
4199 				 "block size (%d)", clustersize, blocksize);
4200 			goto failed_mount;
4201 		}
4202 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4203 			le32_to_cpu(es->s_log_block_size);
4204 		sbi->s_clusters_per_group =
4205 			le32_to_cpu(es->s_clusters_per_group);
4206 		if (sbi->s_clusters_per_group > blocksize * 8) {
4207 			ext4_msg(sb, KERN_ERR,
4208 				 "#clusters per group too big: %lu",
4209 				 sbi->s_clusters_per_group);
4210 			goto failed_mount;
4211 		}
4212 		if (sbi->s_blocks_per_group !=
4213 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4214 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4215 				 "clusters per group (%lu) inconsistent",
4216 				 sbi->s_blocks_per_group,
4217 				 sbi->s_clusters_per_group);
4218 			goto failed_mount;
4219 		}
4220 	} else {
4221 		if (clustersize != blocksize) {
4222 			ext4_msg(sb, KERN_ERR,
4223 				 "fragment/cluster size (%d) != "
4224 				 "block size (%d)", clustersize, blocksize);
4225 			goto failed_mount;
4226 		}
4227 		if (sbi->s_blocks_per_group > blocksize * 8) {
4228 			ext4_msg(sb, KERN_ERR,
4229 				 "#blocks per group too big: %lu",
4230 				 sbi->s_blocks_per_group);
4231 			goto failed_mount;
4232 		}
4233 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4234 		sbi->s_cluster_bits = 0;
4235 	}
4236 	sbi->s_cluster_ratio = clustersize / blocksize;
4237 
4238 	/* Do we have standard group size of clustersize * 8 blocks ? */
4239 	if (sbi->s_blocks_per_group == clustersize << 3)
4240 		set_opt2(sb, STD_GROUP_SIZE);
4241 
4242 	/*
4243 	 * Test whether we have more sectors than will fit in sector_t,
4244 	 * and whether the max offset is addressable by the page cache.
4245 	 */
4246 	err = generic_check_addressable(sb->s_blocksize_bits,
4247 					ext4_blocks_count(es));
4248 	if (err) {
4249 		ext4_msg(sb, KERN_ERR, "filesystem"
4250 			 " too large to mount safely on this system");
4251 		goto failed_mount;
4252 	}
4253 
4254 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4255 		goto cantfind_ext4;
4256 
4257 	/* check blocks count against device size */
4258 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4259 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4260 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4261 		       "exceeds size of device (%llu blocks)",
4262 		       ext4_blocks_count(es), blocks_count);
4263 		goto failed_mount;
4264 	}
4265 
4266 	/*
4267 	 * It makes no sense for the first data block to be beyond the end
4268 	 * of the filesystem.
4269 	 */
4270 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4271 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4272 			 "block %u is beyond end of filesystem (%llu)",
4273 			 le32_to_cpu(es->s_first_data_block),
4274 			 ext4_blocks_count(es));
4275 		goto failed_mount;
4276 	}
4277 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4278 	    (sbi->s_cluster_ratio == 1)) {
4279 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4280 			 "block is 0 with a 1k block and cluster size");
4281 		goto failed_mount;
4282 	}
4283 
4284 	blocks_count = (ext4_blocks_count(es) -
4285 			le32_to_cpu(es->s_first_data_block) +
4286 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4287 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4288 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4289 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4290 		       "(block count %llu, first data block %u, "
4291 		       "blocks per group %lu)", sbi->s_groups_count,
4292 		       ext4_blocks_count(es),
4293 		       le32_to_cpu(es->s_first_data_block),
4294 		       EXT4_BLOCKS_PER_GROUP(sb));
4295 		goto failed_mount;
4296 	}
4297 	sbi->s_groups_count = blocks_count;
4298 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4299 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4300 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4301 	    le32_to_cpu(es->s_inodes_count)) {
4302 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4303 			 le32_to_cpu(es->s_inodes_count),
4304 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4305 		ret = -EINVAL;
4306 		goto failed_mount;
4307 	}
4308 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4309 		   EXT4_DESC_PER_BLOCK(sb);
4310 	if (ext4_has_feature_meta_bg(sb)) {
4311 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4312 			ext4_msg(sb, KERN_WARNING,
4313 				 "first meta block group too large: %u "
4314 				 "(group descriptor block count %u)",
4315 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4316 			goto failed_mount;
4317 		}
4318 	}
4319 	rcu_assign_pointer(sbi->s_group_desc,
4320 			   kvmalloc_array(db_count,
4321 					  sizeof(struct buffer_head *),
4322 					  GFP_KERNEL));
4323 	if (sbi->s_group_desc == NULL) {
4324 		ext4_msg(sb, KERN_ERR, "not enough memory");
4325 		ret = -ENOMEM;
4326 		goto failed_mount;
4327 	}
4328 
4329 	bgl_lock_init(sbi->s_blockgroup_lock);
4330 
4331 	/* Pre-read the descriptors into the buffer cache */
4332 	for (i = 0; i < db_count; i++) {
4333 		block = descriptor_loc(sb, logical_sb_block, i);
4334 		sb_breadahead(sb, block);
4335 	}
4336 
4337 	for (i = 0; i < db_count; i++) {
4338 		struct buffer_head *bh;
4339 
4340 		block = descriptor_loc(sb, logical_sb_block, i);
4341 		bh = sb_bread_unmovable(sb, block);
4342 		if (!bh) {
4343 			ext4_msg(sb, KERN_ERR,
4344 			       "can't read group descriptor %d", i);
4345 			db_count = i;
4346 			goto failed_mount2;
4347 		}
4348 		rcu_read_lock();
4349 		rcu_dereference(sbi->s_group_desc)[i] = bh;
4350 		rcu_read_unlock();
4351 	}
4352 	sbi->s_gdb_count = db_count;
4353 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4354 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4355 		ret = -EFSCORRUPTED;
4356 		goto failed_mount2;
4357 	}
4358 
4359 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4360 
4361 	/* Register extent status tree shrinker */
4362 	if (ext4_es_register_shrinker(sbi))
4363 		goto failed_mount3;
4364 
4365 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4366 	sbi->s_extent_max_zeroout_kb = 32;
4367 
4368 	/*
4369 	 * set up enough so that it can read an inode
4370 	 */
4371 	sb->s_op = &ext4_sops;
4372 	sb->s_export_op = &ext4_export_ops;
4373 	sb->s_xattr = ext4_xattr_handlers;
4374 #ifdef CONFIG_FS_ENCRYPTION
4375 	sb->s_cop = &ext4_cryptops;
4376 #endif
4377 #ifdef CONFIG_FS_VERITY
4378 	sb->s_vop = &ext4_verityops;
4379 #endif
4380 #ifdef CONFIG_QUOTA
4381 	sb->dq_op = &ext4_quota_operations;
4382 	if (ext4_has_feature_quota(sb))
4383 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4384 	else
4385 		sb->s_qcop = &ext4_qctl_operations;
4386 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4387 #endif
4388 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4389 
4390 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4391 	mutex_init(&sbi->s_orphan_lock);
4392 
4393 	sb->s_root = NULL;
4394 
4395 	needs_recovery = (es->s_last_orphan != 0 ||
4396 			  ext4_has_feature_journal_needs_recovery(sb));
4397 
4398 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4399 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4400 			goto failed_mount3a;
4401 
4402 	/*
4403 	 * The first inode we look at is the journal inode.  Don't try
4404 	 * root first: it may be modified in the journal!
4405 	 */
4406 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4407 		err = ext4_load_journal(sb, es, journal_devnum);
4408 		if (err)
4409 			goto failed_mount3a;
4410 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4411 		   ext4_has_feature_journal_needs_recovery(sb)) {
4412 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4413 		       "suppressed and not mounted read-only");
4414 		goto failed_mount_wq;
4415 	} else {
4416 		/* Nojournal mode, all journal mount options are illegal */
4417 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4418 			ext4_msg(sb, KERN_ERR, "can't mount with "
4419 				 "journal_checksum, fs mounted w/o journal");
4420 			goto failed_mount_wq;
4421 		}
4422 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4423 			ext4_msg(sb, KERN_ERR, "can't mount with "
4424 				 "journal_async_commit, fs mounted w/o journal");
4425 			goto failed_mount_wq;
4426 		}
4427 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4428 			ext4_msg(sb, KERN_ERR, "can't mount with "
4429 				 "commit=%lu, fs mounted w/o journal",
4430 				 sbi->s_commit_interval / HZ);
4431 			goto failed_mount_wq;
4432 		}
4433 		if (EXT4_MOUNT_DATA_FLAGS &
4434 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4435 			ext4_msg(sb, KERN_ERR, "can't mount with "
4436 				 "data=, fs mounted w/o journal");
4437 			goto failed_mount_wq;
4438 		}
4439 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4440 		clear_opt(sb, JOURNAL_CHECKSUM);
4441 		clear_opt(sb, DATA_FLAGS);
4442 		sbi->s_journal = NULL;
4443 		needs_recovery = 0;
4444 		goto no_journal;
4445 	}
4446 
4447 	if (ext4_has_feature_64bit(sb) &&
4448 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4449 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4450 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4451 		goto failed_mount_wq;
4452 	}
4453 
4454 	if (!set_journal_csum_feature_set(sb)) {
4455 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4456 			 "feature set");
4457 		goto failed_mount_wq;
4458 	}
4459 
4460 	/* We have now updated the journal if required, so we can
4461 	 * validate the data journaling mode. */
4462 	switch (test_opt(sb, DATA_FLAGS)) {
4463 	case 0:
4464 		/* No mode set, assume a default based on the journal
4465 		 * capabilities: ORDERED_DATA if the journal can
4466 		 * cope, else JOURNAL_DATA
4467 		 */
4468 		if (jbd2_journal_check_available_features
4469 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4470 			set_opt(sb, ORDERED_DATA);
4471 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4472 		} else {
4473 			set_opt(sb, JOURNAL_DATA);
4474 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4475 		}
4476 		break;
4477 
4478 	case EXT4_MOUNT_ORDERED_DATA:
4479 	case EXT4_MOUNT_WRITEBACK_DATA:
4480 		if (!jbd2_journal_check_available_features
4481 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4482 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4483 			       "requested data journaling mode");
4484 			goto failed_mount_wq;
4485 		}
4486 	default:
4487 		break;
4488 	}
4489 
4490 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4491 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4492 		ext4_msg(sb, KERN_ERR, "can't mount with "
4493 			"journal_async_commit in data=ordered mode");
4494 		goto failed_mount_wq;
4495 	}
4496 
4497 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4498 
4499 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4500 
4501 no_journal:
4502 	if (!test_opt(sb, NO_MBCACHE)) {
4503 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4504 		if (!sbi->s_ea_block_cache) {
4505 			ext4_msg(sb, KERN_ERR,
4506 				 "Failed to create ea_block_cache");
4507 			goto failed_mount_wq;
4508 		}
4509 
4510 		if (ext4_has_feature_ea_inode(sb)) {
4511 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4512 			if (!sbi->s_ea_inode_cache) {
4513 				ext4_msg(sb, KERN_ERR,
4514 					 "Failed to create ea_inode_cache");
4515 				goto failed_mount_wq;
4516 			}
4517 		}
4518 	}
4519 
4520 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4521 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4522 		goto failed_mount_wq;
4523 	}
4524 
4525 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4526 	    !ext4_has_feature_encrypt(sb)) {
4527 		ext4_set_feature_encrypt(sb);
4528 		ext4_commit_super(sb, 1);
4529 	}
4530 
4531 	/*
4532 	 * Get the # of file system overhead blocks from the
4533 	 * superblock if present.
4534 	 */
4535 	if (es->s_overhead_clusters)
4536 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4537 	else {
4538 		err = ext4_calculate_overhead(sb);
4539 		if (err)
4540 			goto failed_mount_wq;
4541 	}
4542 
4543 	/*
4544 	 * The maximum number of concurrent works can be high and
4545 	 * concurrency isn't really necessary.  Limit it to 1.
4546 	 */
4547 	EXT4_SB(sb)->rsv_conversion_wq =
4548 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4549 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4550 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4551 		ret = -ENOMEM;
4552 		goto failed_mount4;
4553 	}
4554 
4555 	/*
4556 	 * The jbd2_journal_load will have done any necessary log recovery,
4557 	 * so we can safely mount the rest of the filesystem now.
4558 	 */
4559 
4560 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4561 	if (IS_ERR(root)) {
4562 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4563 		ret = PTR_ERR(root);
4564 		root = NULL;
4565 		goto failed_mount4;
4566 	}
4567 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4568 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4569 		iput(root);
4570 		goto failed_mount4;
4571 	}
4572 
4573 #ifdef CONFIG_UNICODE
4574 	if (sbi->s_encoding)
4575 		sb->s_d_op = &ext4_dentry_ops;
4576 #endif
4577 
4578 	sb->s_root = d_make_root(root);
4579 	if (!sb->s_root) {
4580 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4581 		ret = -ENOMEM;
4582 		goto failed_mount4;
4583 	}
4584 
4585 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4586 	if (ret == -EROFS) {
4587 		sb->s_flags |= SB_RDONLY;
4588 		ret = 0;
4589 	} else if (ret)
4590 		goto failed_mount4a;
4591 
4592 	ext4_set_resv_clusters(sb);
4593 
4594 	err = ext4_setup_system_zone(sb);
4595 	if (err) {
4596 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4597 			 "zone (%d)", err);
4598 		goto failed_mount4a;
4599 	}
4600 
4601 	ext4_ext_init(sb);
4602 	err = ext4_mb_init(sb);
4603 	if (err) {
4604 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4605 			 err);
4606 		goto failed_mount5;
4607 	}
4608 
4609 	block = ext4_count_free_clusters(sb);
4610 	ext4_free_blocks_count_set(sbi->s_es,
4611 				   EXT4_C2B(sbi, block));
4612 	ext4_superblock_csum_set(sb);
4613 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4614 				  GFP_KERNEL);
4615 	if (!err) {
4616 		unsigned long freei = ext4_count_free_inodes(sb);
4617 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4618 		ext4_superblock_csum_set(sb);
4619 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4620 					  GFP_KERNEL);
4621 	}
4622 	if (!err)
4623 		err = percpu_counter_init(&sbi->s_dirs_counter,
4624 					  ext4_count_dirs(sb), GFP_KERNEL);
4625 	if (!err)
4626 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4627 					  GFP_KERNEL);
4628 	if (!err)
4629 		err = percpu_init_rwsem(&sbi->s_writepages_rwsem);
4630 
4631 	if (err) {
4632 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4633 		goto failed_mount6;
4634 	}
4635 
4636 	if (ext4_has_feature_flex_bg(sb))
4637 		if (!ext4_fill_flex_info(sb)) {
4638 			ext4_msg(sb, KERN_ERR,
4639 			       "unable to initialize "
4640 			       "flex_bg meta info!");
4641 			goto failed_mount6;
4642 		}
4643 
4644 	err = ext4_register_li_request(sb, first_not_zeroed);
4645 	if (err)
4646 		goto failed_mount6;
4647 
4648 	err = ext4_register_sysfs(sb);
4649 	if (err)
4650 		goto failed_mount7;
4651 
4652 #ifdef CONFIG_QUOTA
4653 	/* Enable quota usage during mount. */
4654 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4655 		err = ext4_enable_quotas(sb);
4656 		if (err)
4657 			goto failed_mount8;
4658 	}
4659 #endif  /* CONFIG_QUOTA */
4660 
4661 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4662 	ext4_orphan_cleanup(sb, es);
4663 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4664 	if (needs_recovery) {
4665 		ext4_msg(sb, KERN_INFO, "recovery complete");
4666 		ext4_mark_recovery_complete(sb, es);
4667 	}
4668 	if (EXT4_SB(sb)->s_journal) {
4669 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4670 			descr = " journalled data mode";
4671 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4672 			descr = " ordered data mode";
4673 		else
4674 			descr = " writeback data mode";
4675 	} else
4676 		descr = "out journal";
4677 
4678 	if (test_opt(sb, DISCARD)) {
4679 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4680 		if (!blk_queue_discard(q))
4681 			ext4_msg(sb, KERN_WARNING,
4682 				 "mounting with \"discard\" option, but "
4683 				 "the device does not support discard");
4684 	}
4685 
4686 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4687 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4688 			 "Opts: %.*s%s%s", descr,
4689 			 (int) sizeof(sbi->s_es->s_mount_opts),
4690 			 sbi->s_es->s_mount_opts,
4691 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4692 
4693 	if (es->s_error_count)
4694 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4695 
4696 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4697 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4698 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4699 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4700 
4701 	kfree(orig_data);
4702 	return 0;
4703 
4704 cantfind_ext4:
4705 	if (!silent)
4706 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4707 	goto failed_mount;
4708 
4709 #ifdef CONFIG_QUOTA
4710 failed_mount8:
4711 	ext4_unregister_sysfs(sb);
4712 #endif
4713 failed_mount7:
4714 	ext4_unregister_li_request(sb);
4715 failed_mount6:
4716 	ext4_mb_release(sb);
4717 	rcu_read_lock();
4718 	flex_groups = rcu_dereference(sbi->s_flex_groups);
4719 	if (flex_groups) {
4720 		for (i = 0; i < sbi->s_flex_groups_allocated; i++)
4721 			kvfree(flex_groups[i]);
4722 		kvfree(flex_groups);
4723 	}
4724 	rcu_read_unlock();
4725 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4726 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4727 	percpu_counter_destroy(&sbi->s_dirs_counter);
4728 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4729 	percpu_free_rwsem(&sbi->s_writepages_rwsem);
4730 failed_mount5:
4731 	ext4_ext_release(sb);
4732 	ext4_release_system_zone(sb);
4733 failed_mount4a:
4734 	dput(sb->s_root);
4735 	sb->s_root = NULL;
4736 failed_mount4:
4737 	ext4_msg(sb, KERN_ERR, "mount failed");
4738 	if (EXT4_SB(sb)->rsv_conversion_wq)
4739 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4740 failed_mount_wq:
4741 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4742 	sbi->s_ea_inode_cache = NULL;
4743 
4744 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4745 	sbi->s_ea_block_cache = NULL;
4746 
4747 	if (sbi->s_journal) {
4748 		jbd2_journal_destroy(sbi->s_journal);
4749 		sbi->s_journal = NULL;
4750 	}
4751 failed_mount3a:
4752 	ext4_es_unregister_shrinker(sbi);
4753 failed_mount3:
4754 	del_timer_sync(&sbi->s_err_report);
4755 	if (sbi->s_mmp_tsk)
4756 		kthread_stop(sbi->s_mmp_tsk);
4757 failed_mount2:
4758 	rcu_read_lock();
4759 	group_desc = rcu_dereference(sbi->s_group_desc);
4760 	for (i = 0; i < db_count; i++)
4761 		brelse(group_desc[i]);
4762 	kvfree(group_desc);
4763 	rcu_read_unlock();
4764 failed_mount:
4765 	if (sbi->s_chksum_driver)
4766 		crypto_free_shash(sbi->s_chksum_driver);
4767 
4768 #ifdef CONFIG_UNICODE
4769 	utf8_unload(sbi->s_encoding);
4770 #endif
4771 
4772 #ifdef CONFIG_QUOTA
4773 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4774 		kfree(get_qf_name(sb, sbi, i));
4775 #endif
4776 	ext4_blkdev_remove(sbi);
4777 	brelse(bh);
4778 out_fail:
4779 	sb->s_fs_info = NULL;
4780 	kfree(sbi->s_blockgroup_lock);
4781 out_free_base:
4782 	kfree(sbi);
4783 	kfree(orig_data);
4784 	fs_put_dax(dax_dev);
4785 	return err ? err : ret;
4786 }
4787 
4788 /*
4789  * Setup any per-fs journal parameters now.  We'll do this both on
4790  * initial mount, once the journal has been initialised but before we've
4791  * done any recovery; and again on any subsequent remount.
4792  */
4793 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4794 {
4795 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4796 
4797 	journal->j_commit_interval = sbi->s_commit_interval;
4798 	journal->j_min_batch_time = sbi->s_min_batch_time;
4799 	journal->j_max_batch_time = sbi->s_max_batch_time;
4800 
4801 	write_lock(&journal->j_state_lock);
4802 	if (test_opt(sb, BARRIER))
4803 		journal->j_flags |= JBD2_BARRIER;
4804 	else
4805 		journal->j_flags &= ~JBD2_BARRIER;
4806 	if (test_opt(sb, DATA_ERR_ABORT))
4807 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4808 	else
4809 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4810 	write_unlock(&journal->j_state_lock);
4811 }
4812 
4813 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4814 					     unsigned int journal_inum)
4815 {
4816 	struct inode *journal_inode;
4817 
4818 	/*
4819 	 * Test for the existence of a valid inode on disk.  Bad things
4820 	 * happen if we iget() an unused inode, as the subsequent iput()
4821 	 * will try to delete it.
4822 	 */
4823 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4824 	if (IS_ERR(journal_inode)) {
4825 		ext4_msg(sb, KERN_ERR, "no journal found");
4826 		return NULL;
4827 	}
4828 	if (!journal_inode->i_nlink) {
4829 		make_bad_inode(journal_inode);
4830 		iput(journal_inode);
4831 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4832 		return NULL;
4833 	}
4834 
4835 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4836 		  journal_inode, journal_inode->i_size);
4837 	if (!S_ISREG(journal_inode->i_mode)) {
4838 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4839 		iput(journal_inode);
4840 		return NULL;
4841 	}
4842 	return journal_inode;
4843 }
4844 
4845 static journal_t *ext4_get_journal(struct super_block *sb,
4846 				   unsigned int journal_inum)
4847 {
4848 	struct inode *journal_inode;
4849 	journal_t *journal;
4850 
4851 	BUG_ON(!ext4_has_feature_journal(sb));
4852 
4853 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4854 	if (!journal_inode)
4855 		return NULL;
4856 
4857 	journal = jbd2_journal_init_inode(journal_inode);
4858 	if (!journal) {
4859 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4860 		iput(journal_inode);
4861 		return NULL;
4862 	}
4863 	journal->j_private = sb;
4864 	ext4_init_journal_params(sb, journal);
4865 	return journal;
4866 }
4867 
4868 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4869 				       dev_t j_dev)
4870 {
4871 	struct buffer_head *bh;
4872 	journal_t *journal;
4873 	ext4_fsblk_t start;
4874 	ext4_fsblk_t len;
4875 	int hblock, blocksize;
4876 	ext4_fsblk_t sb_block;
4877 	unsigned long offset;
4878 	struct ext4_super_block *es;
4879 	struct block_device *bdev;
4880 
4881 	BUG_ON(!ext4_has_feature_journal(sb));
4882 
4883 	bdev = ext4_blkdev_get(j_dev, sb);
4884 	if (bdev == NULL)
4885 		return NULL;
4886 
4887 	blocksize = sb->s_blocksize;
4888 	hblock = bdev_logical_block_size(bdev);
4889 	if (blocksize < hblock) {
4890 		ext4_msg(sb, KERN_ERR,
4891 			"blocksize too small for journal device");
4892 		goto out_bdev;
4893 	}
4894 
4895 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4896 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4897 	set_blocksize(bdev, blocksize);
4898 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4899 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4900 		       "external journal");
4901 		goto out_bdev;
4902 	}
4903 
4904 	es = (struct ext4_super_block *) (bh->b_data + offset);
4905 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4906 	    !(le32_to_cpu(es->s_feature_incompat) &
4907 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4908 		ext4_msg(sb, KERN_ERR, "external journal has "
4909 					"bad superblock");
4910 		brelse(bh);
4911 		goto out_bdev;
4912 	}
4913 
4914 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4915 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4916 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4917 		ext4_msg(sb, KERN_ERR, "external journal has "
4918 				       "corrupt superblock");
4919 		brelse(bh);
4920 		goto out_bdev;
4921 	}
4922 
4923 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4924 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4925 		brelse(bh);
4926 		goto out_bdev;
4927 	}
4928 
4929 	len = ext4_blocks_count(es);
4930 	start = sb_block + 1;
4931 	brelse(bh);	/* we're done with the superblock */
4932 
4933 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4934 					start, len, blocksize);
4935 	if (!journal) {
4936 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4937 		goto out_bdev;
4938 	}
4939 	journal->j_private = sb;
4940 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4941 	wait_on_buffer(journal->j_sb_buffer);
4942 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4943 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4944 		goto out_journal;
4945 	}
4946 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4947 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4948 					"user (unsupported) - %d",
4949 			be32_to_cpu(journal->j_superblock->s_nr_users));
4950 		goto out_journal;
4951 	}
4952 	EXT4_SB(sb)->journal_bdev = bdev;
4953 	ext4_init_journal_params(sb, journal);
4954 	return journal;
4955 
4956 out_journal:
4957 	jbd2_journal_destroy(journal);
4958 out_bdev:
4959 	ext4_blkdev_put(bdev);
4960 	return NULL;
4961 }
4962 
4963 static int ext4_load_journal(struct super_block *sb,
4964 			     struct ext4_super_block *es,
4965 			     unsigned long journal_devnum)
4966 {
4967 	journal_t *journal;
4968 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4969 	dev_t journal_dev;
4970 	int err = 0;
4971 	int really_read_only;
4972 
4973 	BUG_ON(!ext4_has_feature_journal(sb));
4974 
4975 	if (journal_devnum &&
4976 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4977 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4978 			"numbers have changed");
4979 		journal_dev = new_decode_dev(journal_devnum);
4980 	} else
4981 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4982 
4983 	really_read_only = bdev_read_only(sb->s_bdev);
4984 
4985 	/*
4986 	 * Are we loading a blank journal or performing recovery after a
4987 	 * crash?  For recovery, we need to check in advance whether we
4988 	 * can get read-write access to the device.
4989 	 */
4990 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4991 		if (sb_rdonly(sb)) {
4992 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4993 					"required on readonly filesystem");
4994 			if (really_read_only) {
4995 				ext4_msg(sb, KERN_ERR, "write access "
4996 					"unavailable, cannot proceed "
4997 					"(try mounting with noload)");
4998 				return -EROFS;
4999 			}
5000 			ext4_msg(sb, KERN_INFO, "write access will "
5001 			       "be enabled during recovery");
5002 		}
5003 	}
5004 
5005 	if (journal_inum && journal_dev) {
5006 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
5007 		       "and inode journals!");
5008 		return -EINVAL;
5009 	}
5010 
5011 	if (journal_inum) {
5012 		if (!(journal = ext4_get_journal(sb, journal_inum)))
5013 			return -EINVAL;
5014 	} else {
5015 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
5016 			return -EINVAL;
5017 	}
5018 
5019 	if (!(journal->j_flags & JBD2_BARRIER))
5020 		ext4_msg(sb, KERN_INFO, "barriers disabled");
5021 
5022 	if (!ext4_has_feature_journal_needs_recovery(sb))
5023 		err = jbd2_journal_wipe(journal, !really_read_only);
5024 	if (!err) {
5025 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
5026 		if (save)
5027 			memcpy(save, ((char *) es) +
5028 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
5029 		err = jbd2_journal_load(journal);
5030 		if (save)
5031 			memcpy(((char *) es) + EXT4_S_ERR_START,
5032 			       save, EXT4_S_ERR_LEN);
5033 		kfree(save);
5034 	}
5035 
5036 	if (err) {
5037 		ext4_msg(sb, KERN_ERR, "error loading journal");
5038 		jbd2_journal_destroy(journal);
5039 		return err;
5040 	}
5041 
5042 	EXT4_SB(sb)->s_journal = journal;
5043 	ext4_clear_journal_err(sb, es);
5044 
5045 	if (!really_read_only && journal_devnum &&
5046 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
5047 		es->s_journal_dev = cpu_to_le32(journal_devnum);
5048 
5049 		/* Make sure we flush the recovery flag to disk. */
5050 		ext4_commit_super(sb, 1);
5051 	}
5052 
5053 	return 0;
5054 }
5055 
5056 static int ext4_commit_super(struct super_block *sb, int sync)
5057 {
5058 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
5059 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
5060 	int error = 0;
5061 
5062 	if (!sbh || block_device_ejected(sb))
5063 		return error;
5064 
5065 	/*
5066 	 * The superblock bh should be mapped, but it might not be if the
5067 	 * device was hot-removed. Not much we can do but fail the I/O.
5068 	 */
5069 	if (!buffer_mapped(sbh))
5070 		return error;
5071 
5072 	/*
5073 	 * If the file system is mounted read-only, don't update the
5074 	 * superblock write time.  This avoids updating the superblock
5075 	 * write time when we are mounting the root file system
5076 	 * read/only but we need to replay the journal; at that point,
5077 	 * for people who are east of GMT and who make their clock
5078 	 * tick in localtime for Windows bug-for-bug compatibility,
5079 	 * the clock is set in the future, and this will cause e2fsck
5080 	 * to complain and force a full file system check.
5081 	 */
5082 	if (!(sb->s_flags & SB_RDONLY))
5083 		ext4_update_tstamp(es, s_wtime);
5084 	if (sb->s_bdev->bd_part)
5085 		es->s_kbytes_written =
5086 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5087 			    ((part_stat_read(sb->s_bdev->bd_part,
5088 					     sectors[STAT_WRITE]) -
5089 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5090 	else
5091 		es->s_kbytes_written =
5092 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5093 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5094 		ext4_free_blocks_count_set(es,
5095 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5096 				&EXT4_SB(sb)->s_freeclusters_counter)));
5097 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5098 		es->s_free_inodes_count =
5099 			cpu_to_le32(percpu_counter_sum_positive(
5100 				&EXT4_SB(sb)->s_freeinodes_counter));
5101 	BUFFER_TRACE(sbh, "marking dirty");
5102 	ext4_superblock_csum_set(sb);
5103 	if (sync)
5104 		lock_buffer(sbh);
5105 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5106 		/*
5107 		 * Oh, dear.  A previous attempt to write the
5108 		 * superblock failed.  This could happen because the
5109 		 * USB device was yanked out.  Or it could happen to
5110 		 * be a transient write error and maybe the block will
5111 		 * be remapped.  Nothing we can do but to retry the
5112 		 * write and hope for the best.
5113 		 */
5114 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5115 		       "superblock detected");
5116 		clear_buffer_write_io_error(sbh);
5117 		set_buffer_uptodate(sbh);
5118 	}
5119 	mark_buffer_dirty(sbh);
5120 	if (sync) {
5121 		unlock_buffer(sbh);
5122 		error = __sync_dirty_buffer(sbh,
5123 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5124 		if (buffer_write_io_error(sbh)) {
5125 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5126 			       "superblock");
5127 			clear_buffer_write_io_error(sbh);
5128 			set_buffer_uptodate(sbh);
5129 		}
5130 	}
5131 	return error;
5132 }
5133 
5134 /*
5135  * Have we just finished recovery?  If so, and if we are mounting (or
5136  * remounting) the filesystem readonly, then we will end up with a
5137  * consistent fs on disk.  Record that fact.
5138  */
5139 static void ext4_mark_recovery_complete(struct super_block *sb,
5140 					struct ext4_super_block *es)
5141 {
5142 	journal_t *journal = EXT4_SB(sb)->s_journal;
5143 
5144 	if (!ext4_has_feature_journal(sb)) {
5145 		BUG_ON(journal != NULL);
5146 		return;
5147 	}
5148 	jbd2_journal_lock_updates(journal);
5149 	if (jbd2_journal_flush(journal) < 0)
5150 		goto out;
5151 
5152 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5153 		ext4_clear_feature_journal_needs_recovery(sb);
5154 		ext4_commit_super(sb, 1);
5155 	}
5156 
5157 out:
5158 	jbd2_journal_unlock_updates(journal);
5159 }
5160 
5161 /*
5162  * If we are mounting (or read-write remounting) a filesystem whose journal
5163  * has recorded an error from a previous lifetime, move that error to the
5164  * main filesystem now.
5165  */
5166 static void ext4_clear_journal_err(struct super_block *sb,
5167 				   struct ext4_super_block *es)
5168 {
5169 	journal_t *journal;
5170 	int j_errno;
5171 	const char *errstr;
5172 
5173 	BUG_ON(!ext4_has_feature_journal(sb));
5174 
5175 	journal = EXT4_SB(sb)->s_journal;
5176 
5177 	/*
5178 	 * Now check for any error status which may have been recorded in the
5179 	 * journal by a prior ext4_error() or ext4_abort()
5180 	 */
5181 
5182 	j_errno = jbd2_journal_errno(journal);
5183 	if (j_errno) {
5184 		char nbuf[16];
5185 
5186 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5187 		ext4_warning(sb, "Filesystem error recorded "
5188 			     "from previous mount: %s", errstr);
5189 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5190 
5191 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5192 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5193 		ext4_commit_super(sb, 1);
5194 
5195 		jbd2_journal_clear_err(journal);
5196 		jbd2_journal_update_sb_errno(journal);
5197 	}
5198 }
5199 
5200 /*
5201  * Force the running and committing transactions to commit,
5202  * and wait on the commit.
5203  */
5204 int ext4_force_commit(struct super_block *sb)
5205 {
5206 	journal_t *journal;
5207 
5208 	if (sb_rdonly(sb))
5209 		return 0;
5210 
5211 	journal = EXT4_SB(sb)->s_journal;
5212 	return ext4_journal_force_commit(journal);
5213 }
5214 
5215 static int ext4_sync_fs(struct super_block *sb, int wait)
5216 {
5217 	int ret = 0;
5218 	tid_t target;
5219 	bool needs_barrier = false;
5220 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5221 
5222 	if (unlikely(ext4_forced_shutdown(sbi)))
5223 		return 0;
5224 
5225 	trace_ext4_sync_fs(sb, wait);
5226 	flush_workqueue(sbi->rsv_conversion_wq);
5227 	/*
5228 	 * Writeback quota in non-journalled quota case - journalled quota has
5229 	 * no dirty dquots
5230 	 */
5231 	dquot_writeback_dquots(sb, -1);
5232 	/*
5233 	 * Data writeback is possible w/o journal transaction, so barrier must
5234 	 * being sent at the end of the function. But we can skip it if
5235 	 * transaction_commit will do it for us.
5236 	 */
5237 	if (sbi->s_journal) {
5238 		target = jbd2_get_latest_transaction(sbi->s_journal);
5239 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5240 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5241 			needs_barrier = true;
5242 
5243 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5244 			if (wait)
5245 				ret = jbd2_log_wait_commit(sbi->s_journal,
5246 							   target);
5247 		}
5248 	} else if (wait && test_opt(sb, BARRIER))
5249 		needs_barrier = true;
5250 	if (needs_barrier) {
5251 		int err;
5252 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5253 		if (!ret)
5254 			ret = err;
5255 	}
5256 
5257 	return ret;
5258 }
5259 
5260 /*
5261  * LVM calls this function before a (read-only) snapshot is created.  This
5262  * gives us a chance to flush the journal completely and mark the fs clean.
5263  *
5264  * Note that only this function cannot bring a filesystem to be in a clean
5265  * state independently. It relies on upper layer to stop all data & metadata
5266  * modifications.
5267  */
5268 static int ext4_freeze(struct super_block *sb)
5269 {
5270 	int error = 0;
5271 	journal_t *journal;
5272 
5273 	if (sb_rdonly(sb))
5274 		return 0;
5275 
5276 	journal = EXT4_SB(sb)->s_journal;
5277 
5278 	if (journal) {
5279 		/* Now we set up the journal barrier. */
5280 		jbd2_journal_lock_updates(journal);
5281 
5282 		/*
5283 		 * Don't clear the needs_recovery flag if we failed to
5284 		 * flush the journal.
5285 		 */
5286 		error = jbd2_journal_flush(journal);
5287 		if (error < 0)
5288 			goto out;
5289 
5290 		/* Journal blocked and flushed, clear needs_recovery flag. */
5291 		ext4_clear_feature_journal_needs_recovery(sb);
5292 	}
5293 
5294 	error = ext4_commit_super(sb, 1);
5295 out:
5296 	if (journal)
5297 		/* we rely on upper layer to stop further updates */
5298 		jbd2_journal_unlock_updates(journal);
5299 	return error;
5300 }
5301 
5302 /*
5303  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5304  * flag here, even though the filesystem is not technically dirty yet.
5305  */
5306 static int ext4_unfreeze(struct super_block *sb)
5307 {
5308 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5309 		return 0;
5310 
5311 	if (EXT4_SB(sb)->s_journal) {
5312 		/* Reset the needs_recovery flag before the fs is unlocked. */
5313 		ext4_set_feature_journal_needs_recovery(sb);
5314 	}
5315 
5316 	ext4_commit_super(sb, 1);
5317 	return 0;
5318 }
5319 
5320 /*
5321  * Structure to save mount options for ext4_remount's benefit
5322  */
5323 struct ext4_mount_options {
5324 	unsigned long s_mount_opt;
5325 	unsigned long s_mount_opt2;
5326 	kuid_t s_resuid;
5327 	kgid_t s_resgid;
5328 	unsigned long s_commit_interval;
5329 	u32 s_min_batch_time, s_max_batch_time;
5330 #ifdef CONFIG_QUOTA
5331 	int s_jquota_fmt;
5332 	char *s_qf_names[EXT4_MAXQUOTAS];
5333 #endif
5334 };
5335 
5336 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5337 {
5338 	struct ext4_super_block *es;
5339 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5340 	unsigned long old_sb_flags;
5341 	struct ext4_mount_options old_opts;
5342 	int enable_quota = 0;
5343 	ext4_group_t g;
5344 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5345 	int err = 0;
5346 #ifdef CONFIG_QUOTA
5347 	int i, j;
5348 	char *to_free[EXT4_MAXQUOTAS];
5349 #endif
5350 	char *orig_data = kstrdup(data, GFP_KERNEL);
5351 
5352 	if (data && !orig_data)
5353 		return -ENOMEM;
5354 
5355 	/* Store the original options */
5356 	old_sb_flags = sb->s_flags;
5357 	old_opts.s_mount_opt = sbi->s_mount_opt;
5358 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5359 	old_opts.s_resuid = sbi->s_resuid;
5360 	old_opts.s_resgid = sbi->s_resgid;
5361 	old_opts.s_commit_interval = sbi->s_commit_interval;
5362 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5363 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5364 #ifdef CONFIG_QUOTA
5365 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5366 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5367 		if (sbi->s_qf_names[i]) {
5368 			char *qf_name = get_qf_name(sb, sbi, i);
5369 
5370 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5371 			if (!old_opts.s_qf_names[i]) {
5372 				for (j = 0; j < i; j++)
5373 					kfree(old_opts.s_qf_names[j]);
5374 				kfree(orig_data);
5375 				return -ENOMEM;
5376 			}
5377 		} else
5378 			old_opts.s_qf_names[i] = NULL;
5379 #endif
5380 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5381 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5382 
5383 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5384 		err = -EINVAL;
5385 		goto restore_opts;
5386 	}
5387 
5388 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5389 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5390 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5391 			 "during remount not supported; ignoring");
5392 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5393 	}
5394 
5395 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5396 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5397 			ext4_msg(sb, KERN_ERR, "can't mount with "
5398 				 "both data=journal and delalloc");
5399 			err = -EINVAL;
5400 			goto restore_opts;
5401 		}
5402 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5403 			ext4_msg(sb, KERN_ERR, "can't mount with "
5404 				 "both data=journal and dioread_nolock");
5405 			err = -EINVAL;
5406 			goto restore_opts;
5407 		}
5408 		if (test_opt(sb, DAX)) {
5409 			ext4_msg(sb, KERN_ERR, "can't mount with "
5410 				 "both data=journal and dax");
5411 			err = -EINVAL;
5412 			goto restore_opts;
5413 		}
5414 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5415 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5416 			ext4_msg(sb, KERN_ERR, "can't mount with "
5417 				"journal_async_commit in data=ordered mode");
5418 			err = -EINVAL;
5419 			goto restore_opts;
5420 		}
5421 	}
5422 
5423 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5424 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5425 		err = -EINVAL;
5426 		goto restore_opts;
5427 	}
5428 
5429 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5430 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5431 			"dax flag with busy inodes while remounting");
5432 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5433 	}
5434 
5435 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5436 		ext4_abort(sb, "Abort forced by user");
5437 
5438 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5439 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5440 
5441 	es = sbi->s_es;
5442 
5443 	if (sbi->s_journal) {
5444 		ext4_init_journal_params(sb, sbi->s_journal);
5445 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5446 	}
5447 
5448 	if (*flags & SB_LAZYTIME)
5449 		sb->s_flags |= SB_LAZYTIME;
5450 
5451 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5452 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5453 			err = -EROFS;
5454 			goto restore_opts;
5455 		}
5456 
5457 		if (*flags & SB_RDONLY) {
5458 			err = sync_filesystem(sb);
5459 			if (err < 0)
5460 				goto restore_opts;
5461 			err = dquot_suspend(sb, -1);
5462 			if (err < 0)
5463 				goto restore_opts;
5464 
5465 			/*
5466 			 * First of all, the unconditional stuff we have to do
5467 			 * to disable replay of the journal when we next remount
5468 			 */
5469 			sb->s_flags |= SB_RDONLY;
5470 
5471 			/*
5472 			 * OK, test if we are remounting a valid rw partition
5473 			 * readonly, and if so set the rdonly flag and then
5474 			 * mark the partition as valid again.
5475 			 */
5476 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5477 			    (sbi->s_mount_state & EXT4_VALID_FS))
5478 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5479 
5480 			if (sbi->s_journal)
5481 				ext4_mark_recovery_complete(sb, es);
5482 			if (sbi->s_mmp_tsk)
5483 				kthread_stop(sbi->s_mmp_tsk);
5484 		} else {
5485 			/* Make sure we can mount this feature set readwrite */
5486 			if (ext4_has_feature_readonly(sb) ||
5487 			    !ext4_feature_set_ok(sb, 0)) {
5488 				err = -EROFS;
5489 				goto restore_opts;
5490 			}
5491 			/*
5492 			 * Make sure the group descriptor checksums
5493 			 * are sane.  If they aren't, refuse to remount r/w.
5494 			 */
5495 			for (g = 0; g < sbi->s_groups_count; g++) {
5496 				struct ext4_group_desc *gdp =
5497 					ext4_get_group_desc(sb, g, NULL);
5498 
5499 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5500 					ext4_msg(sb, KERN_ERR,
5501 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5502 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5503 					       le16_to_cpu(gdp->bg_checksum));
5504 					err = -EFSBADCRC;
5505 					goto restore_opts;
5506 				}
5507 			}
5508 
5509 			/*
5510 			 * If we have an unprocessed orphan list hanging
5511 			 * around from a previously readonly bdev mount,
5512 			 * require a full umount/remount for now.
5513 			 */
5514 			if (es->s_last_orphan) {
5515 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5516 				       "remount RDWR because of unprocessed "
5517 				       "orphan inode list.  Please "
5518 				       "umount/remount instead");
5519 				err = -EINVAL;
5520 				goto restore_opts;
5521 			}
5522 
5523 			/*
5524 			 * Mounting a RDONLY partition read-write, so reread
5525 			 * and store the current valid flag.  (It may have
5526 			 * been changed by e2fsck since we originally mounted
5527 			 * the partition.)
5528 			 */
5529 			if (sbi->s_journal)
5530 				ext4_clear_journal_err(sb, es);
5531 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5532 
5533 			err = ext4_setup_super(sb, es, 0);
5534 			if (err)
5535 				goto restore_opts;
5536 
5537 			sb->s_flags &= ~SB_RDONLY;
5538 			if (ext4_has_feature_mmp(sb))
5539 				if (ext4_multi_mount_protect(sb,
5540 						le64_to_cpu(es->s_mmp_block))) {
5541 					err = -EROFS;
5542 					goto restore_opts;
5543 				}
5544 			enable_quota = 1;
5545 		}
5546 	}
5547 
5548 	/*
5549 	 * Reinitialize lazy itable initialization thread based on
5550 	 * current settings
5551 	 */
5552 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5553 		ext4_unregister_li_request(sb);
5554 	else {
5555 		ext4_group_t first_not_zeroed;
5556 		first_not_zeroed = ext4_has_uninit_itable(sb);
5557 		ext4_register_li_request(sb, first_not_zeroed);
5558 	}
5559 
5560 	ext4_setup_system_zone(sb);
5561 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5562 		err = ext4_commit_super(sb, 1);
5563 		if (err)
5564 			goto restore_opts;
5565 	}
5566 
5567 #ifdef CONFIG_QUOTA
5568 	/* Release old quota file names */
5569 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5570 		kfree(old_opts.s_qf_names[i]);
5571 	if (enable_quota) {
5572 		if (sb_any_quota_suspended(sb))
5573 			dquot_resume(sb, -1);
5574 		else if (ext4_has_feature_quota(sb)) {
5575 			err = ext4_enable_quotas(sb);
5576 			if (err)
5577 				goto restore_opts;
5578 		}
5579 	}
5580 #endif
5581 
5582 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5583 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5584 	kfree(orig_data);
5585 	return 0;
5586 
5587 restore_opts:
5588 	sb->s_flags = old_sb_flags;
5589 	sbi->s_mount_opt = old_opts.s_mount_opt;
5590 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5591 	sbi->s_resuid = old_opts.s_resuid;
5592 	sbi->s_resgid = old_opts.s_resgid;
5593 	sbi->s_commit_interval = old_opts.s_commit_interval;
5594 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5595 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5596 #ifdef CONFIG_QUOTA
5597 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5598 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5599 		to_free[i] = get_qf_name(sb, sbi, i);
5600 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5601 	}
5602 	synchronize_rcu();
5603 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5604 		kfree(to_free[i]);
5605 #endif
5606 	kfree(orig_data);
5607 	return err;
5608 }
5609 
5610 #ifdef CONFIG_QUOTA
5611 static int ext4_statfs_project(struct super_block *sb,
5612 			       kprojid_t projid, struct kstatfs *buf)
5613 {
5614 	struct kqid qid;
5615 	struct dquot *dquot;
5616 	u64 limit;
5617 	u64 curblock;
5618 
5619 	qid = make_kqid_projid(projid);
5620 	dquot = dqget(sb, qid);
5621 	if (IS_ERR(dquot))
5622 		return PTR_ERR(dquot);
5623 	spin_lock(&dquot->dq_dqb_lock);
5624 
5625 	limit = dquot->dq_dqb.dqb_bsoftlimit;
5626 	if (dquot->dq_dqb.dqb_bhardlimit &&
5627 	    (!limit || dquot->dq_dqb.dqb_bhardlimit < limit))
5628 		limit = dquot->dq_dqb.dqb_bhardlimit;
5629 	limit >>= sb->s_blocksize_bits;
5630 
5631 	if (limit && buf->f_blocks > limit) {
5632 		curblock = (dquot->dq_dqb.dqb_curspace +
5633 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5634 		buf->f_blocks = limit;
5635 		buf->f_bfree = buf->f_bavail =
5636 			(buf->f_blocks > curblock) ?
5637 			 (buf->f_blocks - curblock) : 0;
5638 	}
5639 
5640 	limit = dquot->dq_dqb.dqb_isoftlimit;
5641 	if (dquot->dq_dqb.dqb_ihardlimit &&
5642 	    (!limit || dquot->dq_dqb.dqb_ihardlimit < limit))
5643 		limit = dquot->dq_dqb.dqb_ihardlimit;
5644 
5645 	if (limit && buf->f_files > limit) {
5646 		buf->f_files = limit;
5647 		buf->f_ffree =
5648 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5649 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5650 	}
5651 
5652 	spin_unlock(&dquot->dq_dqb_lock);
5653 	dqput(dquot);
5654 	return 0;
5655 }
5656 #endif
5657 
5658 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5659 {
5660 	struct super_block *sb = dentry->d_sb;
5661 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5662 	struct ext4_super_block *es = sbi->s_es;
5663 	ext4_fsblk_t overhead = 0, resv_blocks;
5664 	u64 fsid;
5665 	s64 bfree;
5666 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5667 
5668 	if (!test_opt(sb, MINIX_DF))
5669 		overhead = sbi->s_overhead;
5670 
5671 	buf->f_type = EXT4_SUPER_MAGIC;
5672 	buf->f_bsize = sb->s_blocksize;
5673 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5674 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5675 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5676 	/* prevent underflow in case that few free space is available */
5677 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5678 	buf->f_bavail = buf->f_bfree -
5679 			(ext4_r_blocks_count(es) + resv_blocks);
5680 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5681 		buf->f_bavail = 0;
5682 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5683 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5684 	buf->f_namelen = EXT4_NAME_LEN;
5685 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5686 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5687 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5688 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5689 
5690 #ifdef CONFIG_QUOTA
5691 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5692 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5693 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5694 #endif
5695 	return 0;
5696 }
5697 
5698 
5699 #ifdef CONFIG_QUOTA
5700 
5701 /*
5702  * Helper functions so that transaction is started before we acquire dqio_sem
5703  * to keep correct lock ordering of transaction > dqio_sem
5704  */
5705 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5706 {
5707 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5708 }
5709 
5710 static int ext4_write_dquot(struct dquot *dquot)
5711 {
5712 	int ret, err;
5713 	handle_t *handle;
5714 	struct inode *inode;
5715 
5716 	inode = dquot_to_inode(dquot);
5717 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5718 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5719 	if (IS_ERR(handle))
5720 		return PTR_ERR(handle);
5721 	ret = dquot_commit(dquot);
5722 	err = ext4_journal_stop(handle);
5723 	if (!ret)
5724 		ret = err;
5725 	return ret;
5726 }
5727 
5728 static int ext4_acquire_dquot(struct dquot *dquot)
5729 {
5730 	int ret, err;
5731 	handle_t *handle;
5732 
5733 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5734 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5735 	if (IS_ERR(handle))
5736 		return PTR_ERR(handle);
5737 	ret = dquot_acquire(dquot);
5738 	err = ext4_journal_stop(handle);
5739 	if (!ret)
5740 		ret = err;
5741 	return ret;
5742 }
5743 
5744 static int ext4_release_dquot(struct dquot *dquot)
5745 {
5746 	int ret, err;
5747 	handle_t *handle;
5748 
5749 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5750 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5751 	if (IS_ERR(handle)) {
5752 		/* Release dquot anyway to avoid endless cycle in dqput() */
5753 		dquot_release(dquot);
5754 		return PTR_ERR(handle);
5755 	}
5756 	ret = dquot_release(dquot);
5757 	err = ext4_journal_stop(handle);
5758 	if (!ret)
5759 		ret = err;
5760 	return ret;
5761 }
5762 
5763 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5764 {
5765 	struct super_block *sb = dquot->dq_sb;
5766 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5767 
5768 	/* Are we journaling quotas? */
5769 	if (ext4_has_feature_quota(sb) ||
5770 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5771 		dquot_mark_dquot_dirty(dquot);
5772 		return ext4_write_dquot(dquot);
5773 	} else {
5774 		return dquot_mark_dquot_dirty(dquot);
5775 	}
5776 }
5777 
5778 static int ext4_write_info(struct super_block *sb, int type)
5779 {
5780 	int ret, err;
5781 	handle_t *handle;
5782 
5783 	/* Data block + inode block */
5784 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5785 	if (IS_ERR(handle))
5786 		return PTR_ERR(handle);
5787 	ret = dquot_commit_info(sb, type);
5788 	err = ext4_journal_stop(handle);
5789 	if (!ret)
5790 		ret = err;
5791 	return ret;
5792 }
5793 
5794 /*
5795  * Turn on quotas during mount time - we need to find
5796  * the quota file and such...
5797  */
5798 static int ext4_quota_on_mount(struct super_block *sb, int type)
5799 {
5800 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5801 					EXT4_SB(sb)->s_jquota_fmt, type);
5802 }
5803 
5804 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5805 {
5806 	struct ext4_inode_info *ei = EXT4_I(inode);
5807 
5808 	/* The first argument of lockdep_set_subclass has to be
5809 	 * *exactly* the same as the argument to init_rwsem() --- in
5810 	 * this case, in init_once() --- or lockdep gets unhappy
5811 	 * because the name of the lock is set using the
5812 	 * stringification of the argument to init_rwsem().
5813 	 */
5814 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5815 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5816 }
5817 
5818 /*
5819  * Standard function to be called on quota_on
5820  */
5821 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5822 			 const struct path *path)
5823 {
5824 	int err;
5825 
5826 	if (!test_opt(sb, QUOTA))
5827 		return -EINVAL;
5828 
5829 	/* Quotafile not on the same filesystem? */
5830 	if (path->dentry->d_sb != sb)
5831 		return -EXDEV;
5832 	/* Journaling quota? */
5833 	if (EXT4_SB(sb)->s_qf_names[type]) {
5834 		/* Quotafile not in fs root? */
5835 		if (path->dentry->d_parent != sb->s_root)
5836 			ext4_msg(sb, KERN_WARNING,
5837 				"Quota file not on filesystem root. "
5838 				"Journaled quota will not work");
5839 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5840 	} else {
5841 		/*
5842 		 * Clear the flag just in case mount options changed since
5843 		 * last time.
5844 		 */
5845 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5846 	}
5847 
5848 	/*
5849 	 * When we journal data on quota file, we have to flush journal to see
5850 	 * all updates to the file when we bypass pagecache...
5851 	 */
5852 	if (EXT4_SB(sb)->s_journal &&
5853 	    ext4_should_journal_data(d_inode(path->dentry))) {
5854 		/*
5855 		 * We don't need to lock updates but journal_flush() could
5856 		 * otherwise be livelocked...
5857 		 */
5858 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5859 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5860 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5861 		if (err)
5862 			return err;
5863 	}
5864 
5865 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5866 	err = dquot_quota_on(sb, type, format_id, path);
5867 	if (err) {
5868 		lockdep_set_quota_inode(path->dentry->d_inode,
5869 					     I_DATA_SEM_NORMAL);
5870 	} else {
5871 		struct inode *inode = d_inode(path->dentry);
5872 		handle_t *handle;
5873 
5874 		/*
5875 		 * Set inode flags to prevent userspace from messing with quota
5876 		 * files. If this fails, we return success anyway since quotas
5877 		 * are already enabled and this is not a hard failure.
5878 		 */
5879 		inode_lock(inode);
5880 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5881 		if (IS_ERR(handle))
5882 			goto unlock_inode;
5883 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5884 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5885 				S_NOATIME | S_IMMUTABLE);
5886 		ext4_mark_inode_dirty(handle, inode);
5887 		ext4_journal_stop(handle);
5888 	unlock_inode:
5889 		inode_unlock(inode);
5890 	}
5891 	return err;
5892 }
5893 
5894 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5895 			     unsigned int flags)
5896 {
5897 	int err;
5898 	struct inode *qf_inode;
5899 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5900 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5901 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5902 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5903 	};
5904 
5905 	BUG_ON(!ext4_has_feature_quota(sb));
5906 
5907 	if (!qf_inums[type])
5908 		return -EPERM;
5909 
5910 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5911 	if (IS_ERR(qf_inode)) {
5912 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5913 		return PTR_ERR(qf_inode);
5914 	}
5915 
5916 	/* Don't account quota for quota files to avoid recursion */
5917 	qf_inode->i_flags |= S_NOQUOTA;
5918 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5919 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
5920 	if (err)
5921 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5922 	iput(qf_inode);
5923 
5924 	return err;
5925 }
5926 
5927 /* Enable usage tracking for all quota types. */
5928 static int ext4_enable_quotas(struct super_block *sb)
5929 {
5930 	int type, err = 0;
5931 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5932 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5933 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5934 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5935 	};
5936 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5937 		test_opt(sb, USRQUOTA),
5938 		test_opt(sb, GRPQUOTA),
5939 		test_opt(sb, PRJQUOTA),
5940 	};
5941 
5942 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5943 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5944 		if (qf_inums[type]) {
5945 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5946 				DQUOT_USAGE_ENABLED |
5947 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5948 			if (err) {
5949 				ext4_warning(sb,
5950 					"Failed to enable quota tracking "
5951 					"(type=%d, err=%d). Please run "
5952 					"e2fsck to fix.", type, err);
5953 				for (type--; type >= 0; type--)
5954 					dquot_quota_off(sb, type);
5955 
5956 				return err;
5957 			}
5958 		}
5959 	}
5960 	return 0;
5961 }
5962 
5963 static int ext4_quota_off(struct super_block *sb, int type)
5964 {
5965 	struct inode *inode = sb_dqopt(sb)->files[type];
5966 	handle_t *handle;
5967 	int err;
5968 
5969 	/* Force all delayed allocation blocks to be allocated.
5970 	 * Caller already holds s_umount sem */
5971 	if (test_opt(sb, DELALLOC))
5972 		sync_filesystem(sb);
5973 
5974 	if (!inode || !igrab(inode))
5975 		goto out;
5976 
5977 	err = dquot_quota_off(sb, type);
5978 	if (err || ext4_has_feature_quota(sb))
5979 		goto out_put;
5980 
5981 	inode_lock(inode);
5982 	/*
5983 	 * Update modification times of quota files when userspace can
5984 	 * start looking at them. If we fail, we return success anyway since
5985 	 * this is not a hard failure and quotas are already disabled.
5986 	 */
5987 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5988 	if (IS_ERR(handle))
5989 		goto out_unlock;
5990 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5991 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5992 	inode->i_mtime = inode->i_ctime = current_time(inode);
5993 	ext4_mark_inode_dirty(handle, inode);
5994 	ext4_journal_stop(handle);
5995 out_unlock:
5996 	inode_unlock(inode);
5997 out_put:
5998 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5999 	iput(inode);
6000 	return err;
6001 out:
6002 	return dquot_quota_off(sb, type);
6003 }
6004 
6005 /* Read data from quotafile - avoid pagecache and such because we cannot afford
6006  * acquiring the locks... As quota files are never truncated and quota code
6007  * itself serializes the operations (and no one else should touch the files)
6008  * we don't have to be afraid of races */
6009 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
6010 			       size_t len, loff_t off)
6011 {
6012 	struct inode *inode = sb_dqopt(sb)->files[type];
6013 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6014 	int offset = off & (sb->s_blocksize - 1);
6015 	int tocopy;
6016 	size_t toread;
6017 	struct buffer_head *bh;
6018 	loff_t i_size = i_size_read(inode);
6019 
6020 	if (off > i_size)
6021 		return 0;
6022 	if (off+len > i_size)
6023 		len = i_size-off;
6024 	toread = len;
6025 	while (toread > 0) {
6026 		tocopy = sb->s_blocksize - offset < toread ?
6027 				sb->s_blocksize - offset : toread;
6028 		bh = ext4_bread(NULL, inode, blk, 0);
6029 		if (IS_ERR(bh))
6030 			return PTR_ERR(bh);
6031 		if (!bh)	/* A hole? */
6032 			memset(data, 0, tocopy);
6033 		else
6034 			memcpy(data, bh->b_data+offset, tocopy);
6035 		brelse(bh);
6036 		offset = 0;
6037 		toread -= tocopy;
6038 		data += tocopy;
6039 		blk++;
6040 	}
6041 	return len;
6042 }
6043 
6044 /* Write to quotafile (we know the transaction is already started and has
6045  * enough credits) */
6046 static ssize_t ext4_quota_write(struct super_block *sb, int type,
6047 				const char *data, size_t len, loff_t off)
6048 {
6049 	struct inode *inode = sb_dqopt(sb)->files[type];
6050 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
6051 	int err, offset = off & (sb->s_blocksize - 1);
6052 	int retries = 0;
6053 	struct buffer_head *bh;
6054 	handle_t *handle = journal_current_handle();
6055 
6056 	if (EXT4_SB(sb)->s_journal && !handle) {
6057 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6058 			" cancelled because transaction is not started",
6059 			(unsigned long long)off, (unsigned long long)len);
6060 		return -EIO;
6061 	}
6062 	/*
6063 	 * Since we account only one data block in transaction credits,
6064 	 * then it is impossible to cross a block boundary.
6065 	 */
6066 	if (sb->s_blocksize - offset < len) {
6067 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6068 			" cancelled because not block aligned",
6069 			(unsigned long long)off, (unsigned long long)len);
6070 		return -EIO;
6071 	}
6072 
6073 	do {
6074 		bh = ext4_bread(handle, inode, blk,
6075 				EXT4_GET_BLOCKS_CREATE |
6076 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6077 	} while (PTR_ERR(bh) == -ENOSPC &&
6078 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6079 	if (IS_ERR(bh))
6080 		return PTR_ERR(bh);
6081 	if (!bh)
6082 		goto out;
6083 	BUFFER_TRACE(bh, "get write access");
6084 	err = ext4_journal_get_write_access(handle, bh);
6085 	if (err) {
6086 		brelse(bh);
6087 		return err;
6088 	}
6089 	lock_buffer(bh);
6090 	memcpy(bh->b_data+offset, data, len);
6091 	flush_dcache_page(bh->b_page);
6092 	unlock_buffer(bh);
6093 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6094 	brelse(bh);
6095 out:
6096 	if (inode->i_size < off + len) {
6097 		i_size_write(inode, off + len);
6098 		EXT4_I(inode)->i_disksize = inode->i_size;
6099 		ext4_mark_inode_dirty(handle, inode);
6100 	}
6101 	return len;
6102 }
6103 #endif
6104 
6105 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6106 		       const char *dev_name, void *data)
6107 {
6108 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6109 }
6110 
6111 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6112 static inline void register_as_ext2(void)
6113 {
6114 	int err = register_filesystem(&ext2_fs_type);
6115 	if (err)
6116 		printk(KERN_WARNING
6117 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6118 }
6119 
6120 static inline void unregister_as_ext2(void)
6121 {
6122 	unregister_filesystem(&ext2_fs_type);
6123 }
6124 
6125 static inline int ext2_feature_set_ok(struct super_block *sb)
6126 {
6127 	if (ext4_has_unknown_ext2_incompat_features(sb))
6128 		return 0;
6129 	if (sb_rdonly(sb))
6130 		return 1;
6131 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6132 		return 0;
6133 	return 1;
6134 }
6135 #else
6136 static inline void register_as_ext2(void) { }
6137 static inline void unregister_as_ext2(void) { }
6138 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6139 #endif
6140 
6141 static inline void register_as_ext3(void)
6142 {
6143 	int err = register_filesystem(&ext3_fs_type);
6144 	if (err)
6145 		printk(KERN_WARNING
6146 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6147 }
6148 
6149 static inline void unregister_as_ext3(void)
6150 {
6151 	unregister_filesystem(&ext3_fs_type);
6152 }
6153 
6154 static inline int ext3_feature_set_ok(struct super_block *sb)
6155 {
6156 	if (ext4_has_unknown_ext3_incompat_features(sb))
6157 		return 0;
6158 	if (!ext4_has_feature_journal(sb))
6159 		return 0;
6160 	if (sb_rdonly(sb))
6161 		return 1;
6162 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6163 		return 0;
6164 	return 1;
6165 }
6166 
6167 static struct file_system_type ext4_fs_type = {
6168 	.owner		= THIS_MODULE,
6169 	.name		= "ext4",
6170 	.mount		= ext4_mount,
6171 	.kill_sb	= kill_block_super,
6172 	.fs_flags	= FS_REQUIRES_DEV,
6173 };
6174 MODULE_ALIAS_FS("ext4");
6175 
6176 /* Shared across all ext4 file systems */
6177 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6178 
6179 static int __init ext4_init_fs(void)
6180 {
6181 	int i, err;
6182 
6183 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6184 	ext4_li_info = NULL;
6185 	mutex_init(&ext4_li_mtx);
6186 
6187 	/* Build-time check for flags consistency */
6188 	ext4_check_flag_values();
6189 
6190 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6191 		init_waitqueue_head(&ext4__ioend_wq[i]);
6192 
6193 	err = ext4_init_es();
6194 	if (err)
6195 		return err;
6196 
6197 	err = ext4_init_pending();
6198 	if (err)
6199 		goto out7;
6200 
6201 	err = ext4_init_post_read_processing();
6202 	if (err)
6203 		goto out6;
6204 
6205 	err = ext4_init_pageio();
6206 	if (err)
6207 		goto out5;
6208 
6209 	err = ext4_init_system_zone();
6210 	if (err)
6211 		goto out4;
6212 
6213 	err = ext4_init_sysfs();
6214 	if (err)
6215 		goto out3;
6216 
6217 	err = ext4_init_mballoc();
6218 	if (err)
6219 		goto out2;
6220 	err = init_inodecache();
6221 	if (err)
6222 		goto out1;
6223 	register_as_ext3();
6224 	register_as_ext2();
6225 	err = register_filesystem(&ext4_fs_type);
6226 	if (err)
6227 		goto out;
6228 
6229 	return 0;
6230 out:
6231 	unregister_as_ext2();
6232 	unregister_as_ext3();
6233 	destroy_inodecache();
6234 out1:
6235 	ext4_exit_mballoc();
6236 out2:
6237 	ext4_exit_sysfs();
6238 out3:
6239 	ext4_exit_system_zone();
6240 out4:
6241 	ext4_exit_pageio();
6242 out5:
6243 	ext4_exit_post_read_processing();
6244 out6:
6245 	ext4_exit_pending();
6246 out7:
6247 	ext4_exit_es();
6248 
6249 	return err;
6250 }
6251 
6252 static void __exit ext4_exit_fs(void)
6253 {
6254 	ext4_destroy_lazyinit_thread();
6255 	unregister_as_ext2();
6256 	unregister_as_ext3();
6257 	unregister_filesystem(&ext4_fs_type);
6258 	destroy_inodecache();
6259 	ext4_exit_mballoc();
6260 	ext4_exit_sysfs();
6261 	ext4_exit_system_zone();
6262 	ext4_exit_pageio();
6263 	ext4_exit_post_read_processing();
6264 	ext4_exit_es();
6265 	ext4_exit_pending();
6266 }
6267 
6268 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6269 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6270 MODULE_LICENSE("GPL");
6271 MODULE_SOFTDEP("pre: crc32c");
6272 module_init(ext4_init_fs)
6273 module_exit(ext4_exit_fs)
6274