xref: /linux/fs/ext4/super.c (revision 79b6bb73f888933cbcd20b0ef3976cde67951b72)
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 (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 void *ext4_kvmalloc(size_t size, gfp_t flags)
208 {
209 	void *ret;
210 
211 	ret = kmalloc(size, flags | __GFP_NOWARN);
212 	if (!ret)
213 		ret = __vmalloc(size, flags, PAGE_KERNEL);
214 	return ret;
215 }
216 
217 void *ext4_kvzalloc(size_t size, gfp_t flags)
218 {
219 	void *ret;
220 
221 	ret = kzalloc(size, flags | __GFP_NOWARN);
222 	if (!ret)
223 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
224 	return ret;
225 }
226 
227 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
228 			       struct ext4_group_desc *bg)
229 {
230 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
231 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
233 }
234 
235 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
236 			       struct ext4_group_desc *bg)
237 {
238 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
239 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
240 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
241 }
242 
243 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
244 			      struct ext4_group_desc *bg)
245 {
246 	return le32_to_cpu(bg->bg_inode_table_lo) |
247 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
248 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
249 }
250 
251 __u32 ext4_free_group_clusters(struct super_block *sb,
252 			       struct ext4_group_desc *bg)
253 {
254 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
255 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
256 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
257 }
258 
259 __u32 ext4_free_inodes_count(struct super_block *sb,
260 			      struct ext4_group_desc *bg)
261 {
262 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
263 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
264 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
265 }
266 
267 __u32 ext4_used_dirs_count(struct super_block *sb,
268 			      struct ext4_group_desc *bg)
269 {
270 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
271 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
272 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
273 }
274 
275 __u32 ext4_itable_unused_count(struct super_block *sb,
276 			      struct ext4_group_desc *bg)
277 {
278 	return le16_to_cpu(bg->bg_itable_unused_lo) |
279 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
280 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
281 }
282 
283 void ext4_block_bitmap_set(struct super_block *sb,
284 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
285 {
286 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
287 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
289 }
290 
291 void ext4_inode_bitmap_set(struct super_block *sb,
292 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
293 {
294 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
295 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
296 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
297 }
298 
299 void ext4_inode_table_set(struct super_block *sb,
300 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
301 {
302 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
303 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
304 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
305 }
306 
307 void ext4_free_group_clusters_set(struct super_block *sb,
308 				  struct ext4_group_desc *bg, __u32 count)
309 {
310 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
311 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
312 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
313 }
314 
315 void ext4_free_inodes_set(struct super_block *sb,
316 			  struct ext4_group_desc *bg, __u32 count)
317 {
318 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
319 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
320 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
321 }
322 
323 void ext4_used_dirs_set(struct super_block *sb,
324 			  struct ext4_group_desc *bg, __u32 count)
325 {
326 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
327 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
328 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
329 }
330 
331 void ext4_itable_unused_set(struct super_block *sb,
332 			  struct ext4_group_desc *bg, __u32 count)
333 {
334 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
335 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
336 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
337 }
338 
339 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
340 {
341 	time64_t now = ktime_get_real_seconds();
342 
343 	now = clamp_val(now, 0, (1ull << 40) - 1);
344 
345 	*lo = cpu_to_le32(lower_32_bits(now));
346 	*hi = upper_32_bits(now);
347 }
348 
349 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
350 {
351 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
352 }
353 #define ext4_update_tstamp(es, tstamp) \
354 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
355 #define ext4_get_tstamp(es, tstamp) \
356 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
357 
358 static void __save_error_info(struct super_block *sb, const char *func,
359 			    unsigned int line)
360 {
361 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
362 
363 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
364 	if (bdev_read_only(sb->s_bdev))
365 		return;
366 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
367 	ext4_update_tstamp(es, s_last_error_time);
368 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
369 	es->s_last_error_line = cpu_to_le32(line);
370 	if (!es->s_first_error_time) {
371 		es->s_first_error_time = es->s_last_error_time;
372 		es->s_first_error_time_hi = es->s_last_error_time_hi;
373 		strncpy(es->s_first_error_func, func,
374 			sizeof(es->s_first_error_func));
375 		es->s_first_error_line = cpu_to_le32(line);
376 		es->s_first_error_ino = es->s_last_error_ino;
377 		es->s_first_error_block = es->s_last_error_block;
378 	}
379 	/*
380 	 * Start the daily error reporting function if it hasn't been
381 	 * started already
382 	 */
383 	if (!es->s_error_count)
384 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
385 	le32_add_cpu(&es->s_error_count, 1);
386 }
387 
388 static void save_error_info(struct super_block *sb, const char *func,
389 			    unsigned int line)
390 {
391 	__save_error_info(sb, func, line);
392 	ext4_commit_super(sb, 1);
393 }
394 
395 /*
396  * The del_gendisk() function uninitializes the disk-specific data
397  * structures, including the bdi structure, without telling anyone
398  * else.  Once this happens, any attempt to call mark_buffer_dirty()
399  * (for example, by ext4_commit_super), will cause a kernel OOPS.
400  * This is a kludge to prevent these oops until we can put in a proper
401  * hook in del_gendisk() to inform the VFS and file system layers.
402  */
403 static int block_device_ejected(struct super_block *sb)
404 {
405 	struct inode *bd_inode = sb->s_bdev->bd_inode;
406 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
407 
408 	return bdi->dev == NULL;
409 }
410 
411 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
412 {
413 	struct super_block		*sb = journal->j_private;
414 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
415 	int				error = is_journal_aborted(journal);
416 	struct ext4_journal_cb_entry	*jce;
417 
418 	BUG_ON(txn->t_state == T_FINISHED);
419 
420 	ext4_process_freed_data(sb, txn->t_tid);
421 
422 	spin_lock(&sbi->s_md_lock);
423 	while (!list_empty(&txn->t_private_list)) {
424 		jce = list_entry(txn->t_private_list.next,
425 				 struct ext4_journal_cb_entry, jce_list);
426 		list_del_init(&jce->jce_list);
427 		spin_unlock(&sbi->s_md_lock);
428 		jce->jce_func(sb, jce, error);
429 		spin_lock(&sbi->s_md_lock);
430 	}
431 	spin_unlock(&sbi->s_md_lock);
432 }
433 
434 static bool system_going_down(void)
435 {
436 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
437 		|| system_state == SYSTEM_RESTART;
438 }
439 
440 /* Deal with the reporting of failure conditions on a filesystem such as
441  * inconsistencies detected or read IO failures.
442  *
443  * On ext2, we can store the error state of the filesystem in the
444  * superblock.  That is not possible on ext4, because we may have other
445  * write ordering constraints on the superblock which prevent us from
446  * writing it out straight away; and given that the journal is about to
447  * be aborted, we can't rely on the current, or future, transactions to
448  * write out the superblock safely.
449  *
450  * We'll just use the jbd2_journal_abort() error code to record an error in
451  * the journal instead.  On recovery, the journal will complain about
452  * that error until we've noted it down and cleared it.
453  */
454 
455 static void ext4_handle_error(struct super_block *sb)
456 {
457 	if (test_opt(sb, WARN_ON_ERROR))
458 		WARN_ON_ONCE(1);
459 
460 	if (sb_rdonly(sb))
461 		return;
462 
463 	if (!test_opt(sb, ERRORS_CONT)) {
464 		journal_t *journal = EXT4_SB(sb)->s_journal;
465 
466 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
467 		if (journal)
468 			jbd2_journal_abort(journal, -EIO);
469 	}
470 	/*
471 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
472 	 * could panic during 'reboot -f' as the underlying device got already
473 	 * disabled.
474 	 */
475 	if (test_opt(sb, ERRORS_RO) || system_going_down()) {
476 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
477 		/*
478 		 * Make sure updated value of ->s_mount_flags will be visible
479 		 * before ->s_flags update
480 		 */
481 		smp_wmb();
482 		sb->s_flags |= SB_RDONLY;
483 	} else if (test_opt(sb, ERRORS_PANIC)) {
484 		if (EXT4_SB(sb)->s_journal &&
485 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
486 			return;
487 		panic("EXT4-fs (device %s): panic forced after error\n",
488 			sb->s_id);
489 	}
490 }
491 
492 #define ext4_error_ratelimit(sb)					\
493 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
494 			     "EXT4-fs error")
495 
496 void __ext4_error(struct super_block *sb, const char *function,
497 		  unsigned int line, const char *fmt, ...)
498 {
499 	struct va_format vaf;
500 	va_list args;
501 
502 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
503 		return;
504 
505 	trace_ext4_error(sb, function, line);
506 	if (ext4_error_ratelimit(sb)) {
507 		va_start(args, fmt);
508 		vaf.fmt = fmt;
509 		vaf.va = &args;
510 		printk(KERN_CRIT
511 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
512 		       sb->s_id, function, line, current->comm, &vaf);
513 		va_end(args);
514 	}
515 	save_error_info(sb, function, line);
516 	ext4_handle_error(sb);
517 }
518 
519 void __ext4_error_inode(struct inode *inode, const char *function,
520 			unsigned int line, ext4_fsblk_t block,
521 			const char *fmt, ...)
522 {
523 	va_list args;
524 	struct va_format vaf;
525 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
526 
527 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
528 		return;
529 
530 	trace_ext4_error(inode->i_sb, function, line);
531 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
532 	es->s_last_error_block = cpu_to_le64(block);
533 	if (ext4_error_ratelimit(inode->i_sb)) {
534 		va_start(args, fmt);
535 		vaf.fmt = fmt;
536 		vaf.va = &args;
537 		if (block)
538 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
539 			       "inode #%lu: block %llu: comm %s: %pV\n",
540 			       inode->i_sb->s_id, function, line, inode->i_ino,
541 			       block, current->comm, &vaf);
542 		else
543 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
544 			       "inode #%lu: comm %s: %pV\n",
545 			       inode->i_sb->s_id, function, line, inode->i_ino,
546 			       current->comm, &vaf);
547 		va_end(args);
548 	}
549 	save_error_info(inode->i_sb, function, line);
550 	ext4_handle_error(inode->i_sb);
551 }
552 
553 void __ext4_error_file(struct file *file, const char *function,
554 		       unsigned int line, ext4_fsblk_t block,
555 		       const char *fmt, ...)
556 {
557 	va_list args;
558 	struct va_format vaf;
559 	struct ext4_super_block *es;
560 	struct inode *inode = file_inode(file);
561 	char pathname[80], *path;
562 
563 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
564 		return;
565 
566 	trace_ext4_error(inode->i_sb, function, line);
567 	es = EXT4_SB(inode->i_sb)->s_es;
568 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
569 	if (ext4_error_ratelimit(inode->i_sb)) {
570 		path = file_path(file, pathname, sizeof(pathname));
571 		if (IS_ERR(path))
572 			path = "(unknown)";
573 		va_start(args, fmt);
574 		vaf.fmt = fmt;
575 		vaf.va = &args;
576 		if (block)
577 			printk(KERN_CRIT
578 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
579 			       "block %llu: comm %s: path %s: %pV\n",
580 			       inode->i_sb->s_id, function, line, inode->i_ino,
581 			       block, current->comm, path, &vaf);
582 		else
583 			printk(KERN_CRIT
584 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
585 			       "comm %s: path %s: %pV\n",
586 			       inode->i_sb->s_id, function, line, inode->i_ino,
587 			       current->comm, path, &vaf);
588 		va_end(args);
589 	}
590 	save_error_info(inode->i_sb, function, line);
591 	ext4_handle_error(inode->i_sb);
592 }
593 
594 const char *ext4_decode_error(struct super_block *sb, int errno,
595 			      char nbuf[16])
596 {
597 	char *errstr = NULL;
598 
599 	switch (errno) {
600 	case -EFSCORRUPTED:
601 		errstr = "Corrupt filesystem";
602 		break;
603 	case -EFSBADCRC:
604 		errstr = "Filesystem failed CRC";
605 		break;
606 	case -EIO:
607 		errstr = "IO failure";
608 		break;
609 	case -ENOMEM:
610 		errstr = "Out of memory";
611 		break;
612 	case -EROFS:
613 		if (!sb || (EXT4_SB(sb)->s_journal &&
614 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
615 			errstr = "Journal has aborted";
616 		else
617 			errstr = "Readonly filesystem";
618 		break;
619 	default:
620 		/* If the caller passed in an extra buffer for unknown
621 		 * errors, textualise them now.  Else we just return
622 		 * NULL. */
623 		if (nbuf) {
624 			/* Check for truncated error codes... */
625 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
626 				errstr = nbuf;
627 		}
628 		break;
629 	}
630 
631 	return errstr;
632 }
633 
634 /* __ext4_std_error decodes expected errors from journaling functions
635  * automatically and invokes the appropriate error response.  */
636 
637 void __ext4_std_error(struct super_block *sb, const char *function,
638 		      unsigned int line, int errno)
639 {
640 	char nbuf[16];
641 	const char *errstr;
642 
643 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
644 		return;
645 
646 	/* Special case: if the error is EROFS, and we're not already
647 	 * inside a transaction, then there's really no point in logging
648 	 * an error. */
649 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
650 		return;
651 
652 	if (ext4_error_ratelimit(sb)) {
653 		errstr = ext4_decode_error(sb, errno, nbuf);
654 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
655 		       sb->s_id, function, line, errstr);
656 	}
657 
658 	save_error_info(sb, function, line);
659 	ext4_handle_error(sb);
660 }
661 
662 /*
663  * ext4_abort is a much stronger failure handler than ext4_error.  The
664  * abort function may be used to deal with unrecoverable failures such
665  * as journal IO errors or ENOMEM at a critical moment in log management.
666  *
667  * We unconditionally force the filesystem into an ABORT|READONLY state,
668  * unless the error response on the fs has been set to panic in which
669  * case we take the easy way out and panic immediately.
670  */
671 
672 void __ext4_abort(struct super_block *sb, const char *function,
673 		unsigned int line, const char *fmt, ...)
674 {
675 	struct va_format vaf;
676 	va_list args;
677 
678 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
679 		return;
680 
681 	save_error_info(sb, function, line);
682 	va_start(args, fmt);
683 	vaf.fmt = fmt;
684 	vaf.va = &args;
685 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
686 	       sb->s_id, function, line, &vaf);
687 	va_end(args);
688 
689 	if (sb_rdonly(sb) == 0) {
690 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
691 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
692 		/*
693 		 * Make sure updated value of ->s_mount_flags will be visible
694 		 * before ->s_flags update
695 		 */
696 		smp_wmb();
697 		sb->s_flags |= SB_RDONLY;
698 		if (EXT4_SB(sb)->s_journal)
699 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
700 		save_error_info(sb, function, line);
701 	}
702 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
703 		if (EXT4_SB(sb)->s_journal &&
704 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
705 			return;
706 		panic("EXT4-fs panic from previous error\n");
707 	}
708 }
709 
710 void __ext4_msg(struct super_block *sb,
711 		const char *prefix, const char *fmt, ...)
712 {
713 	struct va_format vaf;
714 	va_list args;
715 
716 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
717 		return;
718 
719 	va_start(args, fmt);
720 	vaf.fmt = fmt;
721 	vaf.va = &args;
722 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
723 	va_end(args);
724 }
725 
726 #define ext4_warning_ratelimit(sb)					\
727 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
728 			     "EXT4-fs warning")
729 
730 void __ext4_warning(struct super_block *sb, const char *function,
731 		    unsigned int line, const char *fmt, ...)
732 {
733 	struct va_format vaf;
734 	va_list args;
735 
736 	if (!ext4_warning_ratelimit(sb))
737 		return;
738 
739 	va_start(args, fmt);
740 	vaf.fmt = fmt;
741 	vaf.va = &args;
742 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
743 	       sb->s_id, function, line, &vaf);
744 	va_end(args);
745 }
746 
747 void __ext4_warning_inode(const struct inode *inode, const char *function,
748 			  unsigned int line, const char *fmt, ...)
749 {
750 	struct va_format vaf;
751 	va_list args;
752 
753 	if (!ext4_warning_ratelimit(inode->i_sb))
754 		return;
755 
756 	va_start(args, fmt);
757 	vaf.fmt = fmt;
758 	vaf.va = &args;
759 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
760 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
761 	       function, line, inode->i_ino, current->comm, &vaf);
762 	va_end(args);
763 }
764 
765 void __ext4_grp_locked_error(const char *function, unsigned int line,
766 			     struct super_block *sb, ext4_group_t grp,
767 			     unsigned long ino, ext4_fsblk_t block,
768 			     const char *fmt, ...)
769 __releases(bitlock)
770 __acquires(bitlock)
771 {
772 	struct va_format vaf;
773 	va_list args;
774 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
775 
776 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
777 		return;
778 
779 	trace_ext4_error(sb, function, line);
780 	es->s_last_error_ino = cpu_to_le32(ino);
781 	es->s_last_error_block = cpu_to_le64(block);
782 	__save_error_info(sb, function, line);
783 
784 	if (ext4_error_ratelimit(sb)) {
785 		va_start(args, fmt);
786 		vaf.fmt = fmt;
787 		vaf.va = &args;
788 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
789 		       sb->s_id, function, line, grp);
790 		if (ino)
791 			printk(KERN_CONT "inode %lu: ", ino);
792 		if (block)
793 			printk(KERN_CONT "block %llu:",
794 			       (unsigned long long) block);
795 		printk(KERN_CONT "%pV\n", &vaf);
796 		va_end(args);
797 	}
798 
799 	if (test_opt(sb, WARN_ON_ERROR))
800 		WARN_ON_ONCE(1);
801 
802 	if (test_opt(sb, ERRORS_CONT)) {
803 		ext4_commit_super(sb, 0);
804 		return;
805 	}
806 
807 	ext4_unlock_group(sb, grp);
808 	ext4_commit_super(sb, 1);
809 	ext4_handle_error(sb);
810 	/*
811 	 * We only get here in the ERRORS_RO case; relocking the group
812 	 * may be dangerous, but nothing bad will happen since the
813 	 * filesystem will have already been marked read/only and the
814 	 * journal has been aborted.  We return 1 as a hint to callers
815 	 * who might what to use the return value from
816 	 * ext4_grp_locked_error() to distinguish between the
817 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
818 	 * aggressively from the ext4 function in question, with a
819 	 * more appropriate error code.
820 	 */
821 	ext4_lock_group(sb, grp);
822 	return;
823 }
824 
825 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
826 				     ext4_group_t group,
827 				     unsigned int flags)
828 {
829 	struct ext4_sb_info *sbi = EXT4_SB(sb);
830 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
831 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
832 	int ret;
833 
834 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
835 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
836 					    &grp->bb_state);
837 		if (!ret)
838 			percpu_counter_sub(&sbi->s_freeclusters_counter,
839 					   grp->bb_free);
840 	}
841 
842 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
843 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
844 					    &grp->bb_state);
845 		if (!ret && gdp) {
846 			int count;
847 
848 			count = ext4_free_inodes_count(sb, gdp);
849 			percpu_counter_sub(&sbi->s_freeinodes_counter,
850 					   count);
851 		}
852 	}
853 }
854 
855 void ext4_update_dynamic_rev(struct super_block *sb)
856 {
857 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
858 
859 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
860 		return;
861 
862 	ext4_warning(sb,
863 		     "updating to rev %d because of new feature flag, "
864 		     "running e2fsck is recommended",
865 		     EXT4_DYNAMIC_REV);
866 
867 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
868 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
869 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
870 	/* leave es->s_feature_*compat flags alone */
871 	/* es->s_uuid will be set by e2fsck if empty */
872 
873 	/*
874 	 * The rest of the superblock fields should be zero, and if not it
875 	 * means they are likely already in use, so leave them alone.  We
876 	 * can leave it up to e2fsck to clean up any inconsistencies there.
877 	 */
878 }
879 
880 /*
881  * Open the external journal device
882  */
883 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
884 {
885 	struct block_device *bdev;
886 	char b[BDEVNAME_SIZE];
887 
888 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
889 	if (IS_ERR(bdev))
890 		goto fail;
891 	return bdev;
892 
893 fail:
894 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
895 			__bdevname(dev, b), PTR_ERR(bdev));
896 	return NULL;
897 }
898 
899 /*
900  * Release the journal device
901  */
902 static void ext4_blkdev_put(struct block_device *bdev)
903 {
904 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
905 }
906 
907 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
908 {
909 	struct block_device *bdev;
910 	bdev = sbi->journal_bdev;
911 	if (bdev) {
912 		ext4_blkdev_put(bdev);
913 		sbi->journal_bdev = NULL;
914 	}
915 }
916 
917 static inline struct inode *orphan_list_entry(struct list_head *l)
918 {
919 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
920 }
921 
922 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
923 {
924 	struct list_head *l;
925 
926 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
927 		 le32_to_cpu(sbi->s_es->s_last_orphan));
928 
929 	printk(KERN_ERR "sb_info orphan list:\n");
930 	list_for_each(l, &sbi->s_orphan) {
931 		struct inode *inode = orphan_list_entry(l);
932 		printk(KERN_ERR "  "
933 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
934 		       inode->i_sb->s_id, inode->i_ino, inode,
935 		       inode->i_mode, inode->i_nlink,
936 		       NEXT_ORPHAN(inode));
937 	}
938 }
939 
940 #ifdef CONFIG_QUOTA
941 static int ext4_quota_off(struct super_block *sb, int type);
942 
943 static inline void ext4_quota_off_umount(struct super_block *sb)
944 {
945 	int type;
946 
947 	/* Use our quota_off function to clear inode flags etc. */
948 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
949 		ext4_quota_off(sb, type);
950 }
951 
952 /*
953  * This is a helper function which is used in the mount/remount
954  * codepaths (which holds s_umount) to fetch the quota file name.
955  */
956 static inline char *get_qf_name(struct super_block *sb,
957 				struct ext4_sb_info *sbi,
958 				int type)
959 {
960 	return rcu_dereference_protected(sbi->s_qf_names[type],
961 					 lockdep_is_held(&sb->s_umount));
962 }
963 #else
964 static inline void ext4_quota_off_umount(struct super_block *sb)
965 {
966 }
967 #endif
968 
969 static void ext4_put_super(struct super_block *sb)
970 {
971 	struct ext4_sb_info *sbi = EXT4_SB(sb);
972 	struct ext4_super_block *es = sbi->s_es;
973 	int aborted = 0;
974 	int i, err;
975 
976 	ext4_unregister_li_request(sb);
977 	ext4_quota_off_umount(sb);
978 
979 	destroy_workqueue(sbi->rsv_conversion_wq);
980 
981 	if (sbi->s_journal) {
982 		aborted = is_journal_aborted(sbi->s_journal);
983 		err = jbd2_journal_destroy(sbi->s_journal);
984 		sbi->s_journal = NULL;
985 		if ((err < 0) && !aborted)
986 			ext4_abort(sb, "Couldn't clean up the journal");
987 	}
988 
989 	ext4_unregister_sysfs(sb);
990 	ext4_es_unregister_shrinker(sbi);
991 	del_timer_sync(&sbi->s_err_report);
992 	ext4_release_system_zone(sb);
993 	ext4_mb_release(sb);
994 	ext4_ext_release(sb);
995 
996 	if (!sb_rdonly(sb) && !aborted) {
997 		ext4_clear_feature_journal_needs_recovery(sb);
998 		es->s_state = cpu_to_le16(sbi->s_mount_state);
999 	}
1000 	if (!sb_rdonly(sb))
1001 		ext4_commit_super(sb, 1);
1002 
1003 	for (i = 0; i < sbi->s_gdb_count; i++)
1004 		brelse(sbi->s_group_desc[i]);
1005 	kvfree(sbi->s_group_desc);
1006 	kvfree(sbi->s_flex_groups);
1007 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1008 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1009 	percpu_counter_destroy(&sbi->s_dirs_counter);
1010 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1011 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
1012 #ifdef CONFIG_QUOTA
1013 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1014 		kfree(get_qf_name(sb, sbi, i));
1015 #endif
1016 
1017 	/* Debugging code just in case the in-memory inode orphan list
1018 	 * isn't empty.  The on-disk one can be non-empty if we've
1019 	 * detected an error and taken the fs readonly, but the
1020 	 * in-memory list had better be clean by this point. */
1021 	if (!list_empty(&sbi->s_orphan))
1022 		dump_orphan_list(sb, sbi);
1023 	J_ASSERT(list_empty(&sbi->s_orphan));
1024 
1025 	sync_blockdev(sb->s_bdev);
1026 	invalidate_bdev(sb->s_bdev);
1027 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1028 		/*
1029 		 * Invalidate the journal device's buffers.  We don't want them
1030 		 * floating about in memory - the physical journal device may
1031 		 * hotswapped, and it breaks the `ro-after' testing code.
1032 		 */
1033 		sync_blockdev(sbi->journal_bdev);
1034 		invalidate_bdev(sbi->journal_bdev);
1035 		ext4_blkdev_remove(sbi);
1036 	}
1037 
1038 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1039 	sbi->s_ea_inode_cache = NULL;
1040 
1041 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1042 	sbi->s_ea_block_cache = NULL;
1043 
1044 	if (sbi->s_mmp_tsk)
1045 		kthread_stop(sbi->s_mmp_tsk);
1046 	brelse(sbi->s_sbh);
1047 	sb->s_fs_info = NULL;
1048 	/*
1049 	 * Now that we are completely done shutting down the
1050 	 * superblock, we need to actually destroy the kobject.
1051 	 */
1052 	kobject_put(&sbi->s_kobj);
1053 	wait_for_completion(&sbi->s_kobj_unregister);
1054 	if (sbi->s_chksum_driver)
1055 		crypto_free_shash(sbi->s_chksum_driver);
1056 	kfree(sbi->s_blockgroup_lock);
1057 	fs_put_dax(sbi->s_daxdev);
1058 #ifdef CONFIG_UNICODE
1059 	utf8_unload(sbi->s_encoding);
1060 #endif
1061 	kfree(sbi);
1062 }
1063 
1064 static struct kmem_cache *ext4_inode_cachep;
1065 
1066 /*
1067  * Called inside transaction, so use GFP_NOFS
1068  */
1069 static struct inode *ext4_alloc_inode(struct super_block *sb)
1070 {
1071 	struct ext4_inode_info *ei;
1072 
1073 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1074 	if (!ei)
1075 		return NULL;
1076 
1077 	inode_set_iversion(&ei->vfs_inode, 1);
1078 	spin_lock_init(&ei->i_raw_lock);
1079 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1080 	spin_lock_init(&ei->i_prealloc_lock);
1081 	ext4_es_init_tree(&ei->i_es_tree);
1082 	rwlock_init(&ei->i_es_lock);
1083 	INIT_LIST_HEAD(&ei->i_es_list);
1084 	ei->i_es_all_nr = 0;
1085 	ei->i_es_shk_nr = 0;
1086 	ei->i_es_shrink_lblk = 0;
1087 	ei->i_reserved_data_blocks = 0;
1088 	ei->i_da_metadata_calc_len = 0;
1089 	ei->i_da_metadata_calc_last_lblock = 0;
1090 	spin_lock_init(&(ei->i_block_reservation_lock));
1091 	ext4_init_pending_tree(&ei->i_pending_tree);
1092 #ifdef CONFIG_QUOTA
1093 	ei->i_reserved_quota = 0;
1094 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1095 #endif
1096 	ei->jinode = NULL;
1097 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1098 	spin_lock_init(&ei->i_completed_io_lock);
1099 	ei->i_sync_tid = 0;
1100 	ei->i_datasync_tid = 0;
1101 	atomic_set(&ei->i_unwritten, 0);
1102 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1103 	return &ei->vfs_inode;
1104 }
1105 
1106 static int ext4_drop_inode(struct inode *inode)
1107 {
1108 	int drop = generic_drop_inode(inode);
1109 
1110 	if (!drop)
1111 		drop = fscrypt_drop_inode(inode);
1112 
1113 	trace_ext4_drop_inode(inode, drop);
1114 	return drop;
1115 }
1116 
1117 static void ext4_free_in_core_inode(struct inode *inode)
1118 {
1119 	fscrypt_free_inode(inode);
1120 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1121 }
1122 
1123 static void ext4_destroy_inode(struct inode *inode)
1124 {
1125 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1126 		ext4_msg(inode->i_sb, KERN_ERR,
1127 			 "Inode %lu (%p): orphan list check failed!",
1128 			 inode->i_ino, EXT4_I(inode));
1129 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1130 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1131 				true);
1132 		dump_stack();
1133 	}
1134 }
1135 
1136 static void init_once(void *foo)
1137 {
1138 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1139 
1140 	INIT_LIST_HEAD(&ei->i_orphan);
1141 	init_rwsem(&ei->xattr_sem);
1142 	init_rwsem(&ei->i_data_sem);
1143 	init_rwsem(&ei->i_mmap_sem);
1144 	inode_init_once(&ei->vfs_inode);
1145 }
1146 
1147 static int __init init_inodecache(void)
1148 {
1149 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1150 				sizeof(struct ext4_inode_info), 0,
1151 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1152 					SLAB_ACCOUNT),
1153 				offsetof(struct ext4_inode_info, i_data),
1154 				sizeof_field(struct ext4_inode_info, i_data),
1155 				init_once);
1156 	if (ext4_inode_cachep == NULL)
1157 		return -ENOMEM;
1158 	return 0;
1159 }
1160 
1161 static void destroy_inodecache(void)
1162 {
1163 	/*
1164 	 * Make sure all delayed rcu free inodes are flushed before we
1165 	 * destroy cache.
1166 	 */
1167 	rcu_barrier();
1168 	kmem_cache_destroy(ext4_inode_cachep);
1169 }
1170 
1171 void ext4_clear_inode(struct inode *inode)
1172 {
1173 	invalidate_inode_buffers(inode);
1174 	clear_inode(inode);
1175 	dquot_drop(inode);
1176 	ext4_discard_preallocations(inode);
1177 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1178 	if (EXT4_I(inode)->jinode) {
1179 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1180 					       EXT4_I(inode)->jinode);
1181 		jbd2_free_inode(EXT4_I(inode)->jinode);
1182 		EXT4_I(inode)->jinode = NULL;
1183 	}
1184 	fscrypt_put_encryption_info(inode);
1185 	fsverity_cleanup_inode(inode);
1186 }
1187 
1188 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1189 					u64 ino, u32 generation)
1190 {
1191 	struct inode *inode;
1192 
1193 	/*
1194 	 * Currently we don't know the generation for parent directory, so
1195 	 * a generation of 0 means "accept any"
1196 	 */
1197 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1198 	if (IS_ERR(inode))
1199 		return ERR_CAST(inode);
1200 	if (generation && inode->i_generation != generation) {
1201 		iput(inode);
1202 		return ERR_PTR(-ESTALE);
1203 	}
1204 
1205 	return inode;
1206 }
1207 
1208 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1209 					int fh_len, int fh_type)
1210 {
1211 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1212 				    ext4_nfs_get_inode);
1213 }
1214 
1215 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1216 					int fh_len, int fh_type)
1217 {
1218 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1219 				    ext4_nfs_get_inode);
1220 }
1221 
1222 static int ext4_nfs_commit_metadata(struct inode *inode)
1223 {
1224 	struct writeback_control wbc = {
1225 		.sync_mode = WB_SYNC_ALL
1226 	};
1227 
1228 	trace_ext4_nfs_commit_metadata(inode);
1229 	return ext4_write_inode(inode, &wbc);
1230 }
1231 
1232 /*
1233  * Try to release metadata pages (indirect blocks, directories) which are
1234  * mapped via the block device.  Since these pages could have journal heads
1235  * which would prevent try_to_free_buffers() from freeing them, we must use
1236  * jbd2 layer's try_to_free_buffers() function to release them.
1237  */
1238 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1239 				 gfp_t wait)
1240 {
1241 	journal_t *journal = EXT4_SB(sb)->s_journal;
1242 
1243 	WARN_ON(PageChecked(page));
1244 	if (!page_has_buffers(page))
1245 		return 0;
1246 	if (journal)
1247 		return jbd2_journal_try_to_free_buffers(journal, page,
1248 						wait & ~__GFP_DIRECT_RECLAIM);
1249 	return try_to_free_buffers(page);
1250 }
1251 
1252 #ifdef CONFIG_FS_ENCRYPTION
1253 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1254 {
1255 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1256 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1257 }
1258 
1259 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1260 							void *fs_data)
1261 {
1262 	handle_t *handle = fs_data;
1263 	int res, res2, credits, retries = 0;
1264 
1265 	/*
1266 	 * Encrypting the root directory is not allowed because e2fsck expects
1267 	 * lost+found to exist and be unencrypted, and encrypting the root
1268 	 * directory would imply encrypting the lost+found directory as well as
1269 	 * the filename "lost+found" itself.
1270 	 */
1271 	if (inode->i_ino == EXT4_ROOT_INO)
1272 		return -EPERM;
1273 
1274 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1275 		return -EINVAL;
1276 
1277 	res = ext4_convert_inline_data(inode);
1278 	if (res)
1279 		return res;
1280 
1281 	/*
1282 	 * If a journal handle was specified, then the encryption context is
1283 	 * being set on a new inode via inheritance and is part of a larger
1284 	 * transaction to create the inode.  Otherwise the encryption context is
1285 	 * being set on an existing inode in its own transaction.  Only in the
1286 	 * latter case should the "retry on ENOSPC" logic be used.
1287 	 */
1288 
1289 	if (handle) {
1290 		res = ext4_xattr_set_handle(handle, inode,
1291 					    EXT4_XATTR_INDEX_ENCRYPTION,
1292 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1293 					    ctx, len, 0);
1294 		if (!res) {
1295 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1296 			ext4_clear_inode_state(inode,
1297 					EXT4_STATE_MAY_INLINE_DATA);
1298 			/*
1299 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1300 			 * S_DAX may be disabled
1301 			 */
1302 			ext4_set_inode_flags(inode);
1303 		}
1304 		return res;
1305 	}
1306 
1307 	res = dquot_initialize(inode);
1308 	if (res)
1309 		return res;
1310 retry:
1311 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1312 				     &credits);
1313 	if (res)
1314 		return res;
1315 
1316 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1317 	if (IS_ERR(handle))
1318 		return PTR_ERR(handle);
1319 
1320 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1321 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1322 				    ctx, len, 0);
1323 	if (!res) {
1324 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1325 		/*
1326 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1327 		 * S_DAX may be disabled
1328 		 */
1329 		ext4_set_inode_flags(inode);
1330 		res = ext4_mark_inode_dirty(handle, inode);
1331 		if (res)
1332 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1333 	}
1334 	res2 = ext4_journal_stop(handle);
1335 
1336 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1337 		goto retry;
1338 	if (!res)
1339 		res = res2;
1340 	return res;
1341 }
1342 
1343 static bool ext4_dummy_context(struct inode *inode)
1344 {
1345 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1346 }
1347 
1348 static bool ext4_has_stable_inodes(struct super_block *sb)
1349 {
1350 	return ext4_has_feature_stable_inodes(sb);
1351 }
1352 
1353 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1354 				       int *ino_bits_ret, int *lblk_bits_ret)
1355 {
1356 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1357 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1358 }
1359 
1360 static const struct fscrypt_operations ext4_cryptops = {
1361 	.key_prefix		= "ext4:",
1362 	.get_context		= ext4_get_context,
1363 	.set_context		= ext4_set_context,
1364 	.dummy_context		= ext4_dummy_context,
1365 	.empty_dir		= ext4_empty_dir,
1366 	.max_namelen		= EXT4_NAME_LEN,
1367 	.has_stable_inodes	= ext4_has_stable_inodes,
1368 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1369 };
1370 #endif
1371 
1372 #ifdef CONFIG_QUOTA
1373 static const char * const quotatypes[] = INITQFNAMES;
1374 #define QTYPE2NAME(t) (quotatypes[t])
1375 
1376 static int ext4_write_dquot(struct dquot *dquot);
1377 static int ext4_acquire_dquot(struct dquot *dquot);
1378 static int ext4_release_dquot(struct dquot *dquot);
1379 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1380 static int ext4_write_info(struct super_block *sb, int type);
1381 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1382 			 const struct path *path);
1383 static int ext4_quota_on_mount(struct super_block *sb, int type);
1384 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1385 			       size_t len, loff_t off);
1386 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1387 				const char *data, size_t len, loff_t off);
1388 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1389 			     unsigned int flags);
1390 static int ext4_enable_quotas(struct super_block *sb);
1391 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1392 
1393 static struct dquot **ext4_get_dquots(struct inode *inode)
1394 {
1395 	return EXT4_I(inode)->i_dquot;
1396 }
1397 
1398 static const struct dquot_operations ext4_quota_operations = {
1399 	.get_reserved_space	= ext4_get_reserved_space,
1400 	.write_dquot		= ext4_write_dquot,
1401 	.acquire_dquot		= ext4_acquire_dquot,
1402 	.release_dquot		= ext4_release_dquot,
1403 	.mark_dirty		= ext4_mark_dquot_dirty,
1404 	.write_info		= ext4_write_info,
1405 	.alloc_dquot		= dquot_alloc,
1406 	.destroy_dquot		= dquot_destroy,
1407 	.get_projid		= ext4_get_projid,
1408 	.get_inode_usage	= ext4_get_inode_usage,
1409 	.get_next_id		= ext4_get_next_id,
1410 };
1411 
1412 static const struct quotactl_ops ext4_qctl_operations = {
1413 	.quota_on	= ext4_quota_on,
1414 	.quota_off	= ext4_quota_off,
1415 	.quota_sync	= dquot_quota_sync,
1416 	.get_state	= dquot_get_state,
1417 	.set_info	= dquot_set_dqinfo,
1418 	.get_dqblk	= dquot_get_dqblk,
1419 	.set_dqblk	= dquot_set_dqblk,
1420 	.get_nextdqblk	= dquot_get_next_dqblk,
1421 };
1422 #endif
1423 
1424 static const struct super_operations ext4_sops = {
1425 	.alloc_inode	= ext4_alloc_inode,
1426 	.free_inode	= ext4_free_in_core_inode,
1427 	.destroy_inode	= ext4_destroy_inode,
1428 	.write_inode	= ext4_write_inode,
1429 	.dirty_inode	= ext4_dirty_inode,
1430 	.drop_inode	= ext4_drop_inode,
1431 	.evict_inode	= ext4_evict_inode,
1432 	.put_super	= ext4_put_super,
1433 	.sync_fs	= ext4_sync_fs,
1434 	.freeze_fs	= ext4_freeze,
1435 	.unfreeze_fs	= ext4_unfreeze,
1436 	.statfs		= ext4_statfs,
1437 	.remount_fs	= ext4_remount,
1438 	.show_options	= ext4_show_options,
1439 #ifdef CONFIG_QUOTA
1440 	.quota_read	= ext4_quota_read,
1441 	.quota_write	= ext4_quota_write,
1442 	.get_dquots	= ext4_get_dquots,
1443 #endif
1444 	.bdev_try_to_free_page = bdev_try_to_free_page,
1445 };
1446 
1447 static const struct export_operations ext4_export_ops = {
1448 	.fh_to_dentry = ext4_fh_to_dentry,
1449 	.fh_to_parent = ext4_fh_to_parent,
1450 	.get_parent = ext4_get_parent,
1451 	.commit_metadata = ext4_nfs_commit_metadata,
1452 };
1453 
1454 enum {
1455 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1456 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1457 	Opt_nouid32, Opt_debug, Opt_removed,
1458 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1459 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1460 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1461 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1462 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1463 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1464 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1465 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1466 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1467 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1468 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1469 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1470 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1471 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1472 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1473 	Opt_dioread_nolock, Opt_dioread_lock,
1474 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1475 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1476 };
1477 
1478 static const match_table_t tokens = {
1479 	{Opt_bsd_df, "bsddf"},
1480 	{Opt_minix_df, "minixdf"},
1481 	{Opt_grpid, "grpid"},
1482 	{Opt_grpid, "bsdgroups"},
1483 	{Opt_nogrpid, "nogrpid"},
1484 	{Opt_nogrpid, "sysvgroups"},
1485 	{Opt_resgid, "resgid=%u"},
1486 	{Opt_resuid, "resuid=%u"},
1487 	{Opt_sb, "sb=%u"},
1488 	{Opt_err_cont, "errors=continue"},
1489 	{Opt_err_panic, "errors=panic"},
1490 	{Opt_err_ro, "errors=remount-ro"},
1491 	{Opt_nouid32, "nouid32"},
1492 	{Opt_debug, "debug"},
1493 	{Opt_removed, "oldalloc"},
1494 	{Opt_removed, "orlov"},
1495 	{Opt_user_xattr, "user_xattr"},
1496 	{Opt_nouser_xattr, "nouser_xattr"},
1497 	{Opt_acl, "acl"},
1498 	{Opt_noacl, "noacl"},
1499 	{Opt_noload, "norecovery"},
1500 	{Opt_noload, "noload"},
1501 	{Opt_removed, "nobh"},
1502 	{Opt_removed, "bh"},
1503 	{Opt_commit, "commit=%u"},
1504 	{Opt_min_batch_time, "min_batch_time=%u"},
1505 	{Opt_max_batch_time, "max_batch_time=%u"},
1506 	{Opt_journal_dev, "journal_dev=%u"},
1507 	{Opt_journal_path, "journal_path=%s"},
1508 	{Opt_journal_checksum, "journal_checksum"},
1509 	{Opt_nojournal_checksum, "nojournal_checksum"},
1510 	{Opt_journal_async_commit, "journal_async_commit"},
1511 	{Opt_abort, "abort"},
1512 	{Opt_data_journal, "data=journal"},
1513 	{Opt_data_ordered, "data=ordered"},
1514 	{Opt_data_writeback, "data=writeback"},
1515 	{Opt_data_err_abort, "data_err=abort"},
1516 	{Opt_data_err_ignore, "data_err=ignore"},
1517 	{Opt_offusrjquota, "usrjquota="},
1518 	{Opt_usrjquota, "usrjquota=%s"},
1519 	{Opt_offgrpjquota, "grpjquota="},
1520 	{Opt_grpjquota, "grpjquota=%s"},
1521 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1522 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1523 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1524 	{Opt_grpquota, "grpquota"},
1525 	{Opt_noquota, "noquota"},
1526 	{Opt_quota, "quota"},
1527 	{Opt_usrquota, "usrquota"},
1528 	{Opt_prjquota, "prjquota"},
1529 	{Opt_barrier, "barrier=%u"},
1530 	{Opt_barrier, "barrier"},
1531 	{Opt_nobarrier, "nobarrier"},
1532 	{Opt_i_version, "i_version"},
1533 	{Opt_dax, "dax"},
1534 	{Opt_stripe, "stripe=%u"},
1535 	{Opt_delalloc, "delalloc"},
1536 	{Opt_warn_on_error, "warn_on_error"},
1537 	{Opt_nowarn_on_error, "nowarn_on_error"},
1538 	{Opt_lazytime, "lazytime"},
1539 	{Opt_nolazytime, "nolazytime"},
1540 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1541 	{Opt_nodelalloc, "nodelalloc"},
1542 	{Opt_removed, "mblk_io_submit"},
1543 	{Opt_removed, "nomblk_io_submit"},
1544 	{Opt_block_validity, "block_validity"},
1545 	{Opt_noblock_validity, "noblock_validity"},
1546 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1547 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1548 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1549 	{Opt_auto_da_alloc, "auto_da_alloc"},
1550 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1551 	{Opt_dioread_nolock, "dioread_nolock"},
1552 	{Opt_dioread_lock, "dioread_lock"},
1553 	{Opt_discard, "discard"},
1554 	{Opt_nodiscard, "nodiscard"},
1555 	{Opt_init_itable, "init_itable=%u"},
1556 	{Opt_init_itable, "init_itable"},
1557 	{Opt_noinit_itable, "noinit_itable"},
1558 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1559 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1560 	{Opt_nombcache, "nombcache"},
1561 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1562 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1563 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1564 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1565 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1566 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1567 	{Opt_err, NULL},
1568 };
1569 
1570 static ext4_fsblk_t get_sb_block(void **data)
1571 {
1572 	ext4_fsblk_t	sb_block;
1573 	char		*options = (char *) *data;
1574 
1575 	if (!options || strncmp(options, "sb=", 3) != 0)
1576 		return 1;	/* Default location */
1577 
1578 	options += 3;
1579 	/* TODO: use simple_strtoll with >32bit ext4 */
1580 	sb_block = simple_strtoul(options, &options, 0);
1581 	if (*options && *options != ',') {
1582 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1583 		       (char *) *data);
1584 		return 1;
1585 	}
1586 	if (*options == ',')
1587 		options++;
1588 	*data = (void *) options;
1589 
1590 	return sb_block;
1591 }
1592 
1593 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1594 static const char deprecated_msg[] =
1595 	"Mount option \"%s\" will be removed by %s\n"
1596 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1597 
1598 #ifdef CONFIG_QUOTA
1599 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1600 {
1601 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1602 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1603 	int ret = -1;
1604 
1605 	if (sb_any_quota_loaded(sb) && !old_qname) {
1606 		ext4_msg(sb, KERN_ERR,
1607 			"Cannot change journaled "
1608 			"quota options when quota turned on");
1609 		return -1;
1610 	}
1611 	if (ext4_has_feature_quota(sb)) {
1612 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1613 			 "ignored when QUOTA feature is enabled");
1614 		return 1;
1615 	}
1616 	qname = match_strdup(args);
1617 	if (!qname) {
1618 		ext4_msg(sb, KERN_ERR,
1619 			"Not enough memory for storing quotafile name");
1620 		return -1;
1621 	}
1622 	if (old_qname) {
1623 		if (strcmp(old_qname, qname) == 0)
1624 			ret = 1;
1625 		else
1626 			ext4_msg(sb, KERN_ERR,
1627 				 "%s quota file already specified",
1628 				 QTYPE2NAME(qtype));
1629 		goto errout;
1630 	}
1631 	if (strchr(qname, '/')) {
1632 		ext4_msg(sb, KERN_ERR,
1633 			"quotafile must be on filesystem root");
1634 		goto errout;
1635 	}
1636 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1637 	set_opt(sb, QUOTA);
1638 	return 1;
1639 errout:
1640 	kfree(qname);
1641 	return ret;
1642 }
1643 
1644 static int clear_qf_name(struct super_block *sb, int qtype)
1645 {
1646 
1647 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1648 	char *old_qname = get_qf_name(sb, sbi, qtype);
1649 
1650 	if (sb_any_quota_loaded(sb) && old_qname) {
1651 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1652 			" when quota turned on");
1653 		return -1;
1654 	}
1655 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1656 	synchronize_rcu();
1657 	kfree(old_qname);
1658 	return 1;
1659 }
1660 #endif
1661 
1662 #define MOPT_SET	0x0001
1663 #define MOPT_CLEAR	0x0002
1664 #define MOPT_NOSUPPORT	0x0004
1665 #define MOPT_EXPLICIT	0x0008
1666 #define MOPT_CLEAR_ERR	0x0010
1667 #define MOPT_GTE0	0x0020
1668 #ifdef CONFIG_QUOTA
1669 #define MOPT_Q		0
1670 #define MOPT_QFMT	0x0040
1671 #else
1672 #define MOPT_Q		MOPT_NOSUPPORT
1673 #define MOPT_QFMT	MOPT_NOSUPPORT
1674 #endif
1675 #define MOPT_DATAJ	0x0080
1676 #define MOPT_NO_EXT2	0x0100
1677 #define MOPT_NO_EXT3	0x0200
1678 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1679 #define MOPT_STRING	0x0400
1680 
1681 static const struct mount_opts {
1682 	int	token;
1683 	int	mount_opt;
1684 	int	flags;
1685 } ext4_mount_opts[] = {
1686 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1687 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1688 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1689 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1690 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1691 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1692 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1693 	 MOPT_EXT4_ONLY | MOPT_SET},
1694 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1695 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1696 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1697 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1698 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1699 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1700 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1701 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1702 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1703 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1704 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1705 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1706 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1707 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1708 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1709 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1710 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1711 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1712 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1713 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1714 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1715 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1716 	 MOPT_NO_EXT2},
1717 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1718 	 MOPT_NO_EXT2},
1719 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1720 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1721 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1722 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1723 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1724 	{Opt_commit, 0, MOPT_GTE0},
1725 	{Opt_max_batch_time, 0, MOPT_GTE0},
1726 	{Opt_min_batch_time, 0, MOPT_GTE0},
1727 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1728 	{Opt_init_itable, 0, MOPT_GTE0},
1729 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1730 	{Opt_stripe, 0, MOPT_GTE0},
1731 	{Opt_resuid, 0, MOPT_GTE0},
1732 	{Opt_resgid, 0, MOPT_GTE0},
1733 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1734 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1735 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1736 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1737 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1738 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1739 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1740 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1741 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1742 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1743 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1744 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1745 #else
1746 	{Opt_acl, 0, MOPT_NOSUPPORT},
1747 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1748 #endif
1749 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1750 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1751 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1752 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1753 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1754 							MOPT_SET | MOPT_Q},
1755 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1756 							MOPT_SET | MOPT_Q},
1757 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1758 							MOPT_SET | MOPT_Q},
1759 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1760 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1761 							MOPT_CLEAR | MOPT_Q},
1762 	{Opt_usrjquota, 0, MOPT_Q},
1763 	{Opt_grpjquota, 0, MOPT_Q},
1764 	{Opt_offusrjquota, 0, MOPT_Q},
1765 	{Opt_offgrpjquota, 0, MOPT_Q},
1766 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1767 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1768 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1769 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1770 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1771 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1772 	{Opt_err, 0, 0}
1773 };
1774 
1775 #ifdef CONFIG_UNICODE
1776 static const struct ext4_sb_encodings {
1777 	__u16 magic;
1778 	char *name;
1779 	char *version;
1780 } ext4_sb_encoding_map[] = {
1781 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1782 };
1783 
1784 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1785 				 const struct ext4_sb_encodings **encoding,
1786 				 __u16 *flags)
1787 {
1788 	__u16 magic = le16_to_cpu(es->s_encoding);
1789 	int i;
1790 
1791 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1792 		if (magic == ext4_sb_encoding_map[i].magic)
1793 			break;
1794 
1795 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1796 		return -EINVAL;
1797 
1798 	*encoding = &ext4_sb_encoding_map[i];
1799 	*flags = le16_to_cpu(es->s_encoding_flags);
1800 
1801 	return 0;
1802 }
1803 #endif
1804 
1805 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1806 			    substring_t *args, unsigned long *journal_devnum,
1807 			    unsigned int *journal_ioprio, int is_remount)
1808 {
1809 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1810 	const struct mount_opts *m;
1811 	kuid_t uid;
1812 	kgid_t gid;
1813 	int arg = 0;
1814 
1815 #ifdef CONFIG_QUOTA
1816 	if (token == Opt_usrjquota)
1817 		return set_qf_name(sb, USRQUOTA, &args[0]);
1818 	else if (token == Opt_grpjquota)
1819 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1820 	else if (token == Opt_offusrjquota)
1821 		return clear_qf_name(sb, USRQUOTA);
1822 	else if (token == Opt_offgrpjquota)
1823 		return clear_qf_name(sb, GRPQUOTA);
1824 #endif
1825 	switch (token) {
1826 	case Opt_noacl:
1827 	case Opt_nouser_xattr:
1828 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1829 		break;
1830 	case Opt_sb:
1831 		return 1;	/* handled by get_sb_block() */
1832 	case Opt_removed:
1833 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1834 		return 1;
1835 	case Opt_abort:
1836 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1837 		return 1;
1838 	case Opt_i_version:
1839 		sb->s_flags |= SB_I_VERSION;
1840 		return 1;
1841 	case Opt_lazytime:
1842 		sb->s_flags |= SB_LAZYTIME;
1843 		return 1;
1844 	case Opt_nolazytime:
1845 		sb->s_flags &= ~SB_LAZYTIME;
1846 		return 1;
1847 	}
1848 
1849 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1850 		if (token == m->token)
1851 			break;
1852 
1853 	if (m->token == Opt_err) {
1854 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1855 			 "or missing value", opt);
1856 		return -1;
1857 	}
1858 
1859 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1860 		ext4_msg(sb, KERN_ERR,
1861 			 "Mount option \"%s\" incompatible with ext2", opt);
1862 		return -1;
1863 	}
1864 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1865 		ext4_msg(sb, KERN_ERR,
1866 			 "Mount option \"%s\" incompatible with ext3", opt);
1867 		return -1;
1868 	}
1869 
1870 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1871 		return -1;
1872 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1873 		return -1;
1874 	if (m->flags & MOPT_EXPLICIT) {
1875 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1876 			set_opt2(sb, EXPLICIT_DELALLOC);
1877 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1878 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1879 		} else
1880 			return -1;
1881 	}
1882 	if (m->flags & MOPT_CLEAR_ERR)
1883 		clear_opt(sb, ERRORS_MASK);
1884 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1885 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1886 			 "options when quota turned on");
1887 		return -1;
1888 	}
1889 
1890 	if (m->flags & MOPT_NOSUPPORT) {
1891 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1892 	} else if (token == Opt_commit) {
1893 		if (arg == 0)
1894 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1895 		else if (arg > INT_MAX / HZ) {
1896 			ext4_msg(sb, KERN_ERR,
1897 				 "Invalid commit interval %d, "
1898 				 "must be smaller than %d",
1899 				 arg, INT_MAX / HZ);
1900 			return -1;
1901 		}
1902 		sbi->s_commit_interval = HZ * arg;
1903 	} else if (token == Opt_debug_want_extra_isize) {
1904 		sbi->s_want_extra_isize = arg;
1905 	} else if (token == Opt_max_batch_time) {
1906 		sbi->s_max_batch_time = arg;
1907 	} else if (token == Opt_min_batch_time) {
1908 		sbi->s_min_batch_time = arg;
1909 	} else if (token == Opt_inode_readahead_blks) {
1910 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1911 			ext4_msg(sb, KERN_ERR,
1912 				 "EXT4-fs: inode_readahead_blks must be "
1913 				 "0 or a power of 2 smaller than 2^31");
1914 			return -1;
1915 		}
1916 		sbi->s_inode_readahead_blks = arg;
1917 	} else if (token == Opt_init_itable) {
1918 		set_opt(sb, INIT_INODE_TABLE);
1919 		if (!args->from)
1920 			arg = EXT4_DEF_LI_WAIT_MULT;
1921 		sbi->s_li_wait_mult = arg;
1922 	} else if (token == Opt_max_dir_size_kb) {
1923 		sbi->s_max_dir_size_kb = arg;
1924 	} else if (token == Opt_stripe) {
1925 		sbi->s_stripe = arg;
1926 	} else if (token == Opt_resuid) {
1927 		uid = make_kuid(current_user_ns(), arg);
1928 		if (!uid_valid(uid)) {
1929 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1930 			return -1;
1931 		}
1932 		sbi->s_resuid = uid;
1933 	} else if (token == Opt_resgid) {
1934 		gid = make_kgid(current_user_ns(), arg);
1935 		if (!gid_valid(gid)) {
1936 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1937 			return -1;
1938 		}
1939 		sbi->s_resgid = gid;
1940 	} else if (token == Opt_journal_dev) {
1941 		if (is_remount) {
1942 			ext4_msg(sb, KERN_ERR,
1943 				 "Cannot specify journal on remount");
1944 			return -1;
1945 		}
1946 		*journal_devnum = arg;
1947 	} else if (token == Opt_journal_path) {
1948 		char *journal_path;
1949 		struct inode *journal_inode;
1950 		struct path path;
1951 		int error;
1952 
1953 		if (is_remount) {
1954 			ext4_msg(sb, KERN_ERR,
1955 				 "Cannot specify journal on remount");
1956 			return -1;
1957 		}
1958 		journal_path = match_strdup(&args[0]);
1959 		if (!journal_path) {
1960 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1961 				"journal device string");
1962 			return -1;
1963 		}
1964 
1965 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1966 		if (error) {
1967 			ext4_msg(sb, KERN_ERR, "error: could not find "
1968 				"journal device path: error %d", error);
1969 			kfree(journal_path);
1970 			return -1;
1971 		}
1972 
1973 		journal_inode = d_inode(path.dentry);
1974 		if (!S_ISBLK(journal_inode->i_mode)) {
1975 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1976 				"is not a block device", journal_path);
1977 			path_put(&path);
1978 			kfree(journal_path);
1979 			return -1;
1980 		}
1981 
1982 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1983 		path_put(&path);
1984 		kfree(journal_path);
1985 	} else if (token == Opt_journal_ioprio) {
1986 		if (arg > 7) {
1987 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1988 				 " (must be 0-7)");
1989 			return -1;
1990 		}
1991 		*journal_ioprio =
1992 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1993 	} else if (token == Opt_test_dummy_encryption) {
1994 #ifdef CONFIG_FS_ENCRYPTION
1995 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1996 		ext4_msg(sb, KERN_WARNING,
1997 			 "Test dummy encryption mode enabled");
1998 #else
1999 		ext4_msg(sb, KERN_WARNING,
2000 			 "Test dummy encryption mount option ignored");
2001 #endif
2002 	} else if (m->flags & MOPT_DATAJ) {
2003 		if (is_remount) {
2004 			if (!sbi->s_journal)
2005 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2006 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2007 				ext4_msg(sb, KERN_ERR,
2008 					 "Cannot change data mode on remount");
2009 				return -1;
2010 			}
2011 		} else {
2012 			clear_opt(sb, DATA_FLAGS);
2013 			sbi->s_mount_opt |= m->mount_opt;
2014 		}
2015 #ifdef CONFIG_QUOTA
2016 	} else if (m->flags & MOPT_QFMT) {
2017 		if (sb_any_quota_loaded(sb) &&
2018 		    sbi->s_jquota_fmt != m->mount_opt) {
2019 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2020 				 "quota options when quota turned on");
2021 			return -1;
2022 		}
2023 		if (ext4_has_feature_quota(sb)) {
2024 			ext4_msg(sb, KERN_INFO,
2025 				 "Quota format mount options ignored "
2026 				 "when QUOTA feature is enabled");
2027 			return 1;
2028 		}
2029 		sbi->s_jquota_fmt = m->mount_opt;
2030 #endif
2031 	} else if (token == Opt_dax) {
2032 #ifdef CONFIG_FS_DAX
2033 		ext4_msg(sb, KERN_WARNING,
2034 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2035 		sbi->s_mount_opt |= m->mount_opt;
2036 #else
2037 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2038 		return -1;
2039 #endif
2040 	} else if (token == Opt_data_err_abort) {
2041 		sbi->s_mount_opt |= m->mount_opt;
2042 	} else if (token == Opt_data_err_ignore) {
2043 		sbi->s_mount_opt &= ~m->mount_opt;
2044 	} else {
2045 		if (!args->from)
2046 			arg = 1;
2047 		if (m->flags & MOPT_CLEAR)
2048 			arg = !arg;
2049 		else if (unlikely(!(m->flags & MOPT_SET))) {
2050 			ext4_msg(sb, KERN_WARNING,
2051 				 "buggy handling of option %s", opt);
2052 			WARN_ON(1);
2053 			return -1;
2054 		}
2055 		if (arg != 0)
2056 			sbi->s_mount_opt |= m->mount_opt;
2057 		else
2058 			sbi->s_mount_opt &= ~m->mount_opt;
2059 	}
2060 	return 1;
2061 }
2062 
2063 static int parse_options(char *options, struct super_block *sb,
2064 			 unsigned long *journal_devnum,
2065 			 unsigned int *journal_ioprio,
2066 			 int is_remount)
2067 {
2068 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2069 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2070 	substring_t args[MAX_OPT_ARGS];
2071 	int token;
2072 
2073 	if (!options)
2074 		return 1;
2075 
2076 	while ((p = strsep(&options, ",")) != NULL) {
2077 		if (!*p)
2078 			continue;
2079 		/*
2080 		 * Initialize args struct so we know whether arg was
2081 		 * found; some options take optional arguments.
2082 		 */
2083 		args[0].to = args[0].from = NULL;
2084 		token = match_token(p, tokens, args);
2085 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2086 				     journal_ioprio, is_remount) < 0)
2087 			return 0;
2088 	}
2089 #ifdef CONFIG_QUOTA
2090 	/*
2091 	 * We do the test below only for project quotas. 'usrquota' and
2092 	 * 'grpquota' mount options are allowed even without quota feature
2093 	 * to support legacy quotas in quota files.
2094 	 */
2095 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2096 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2097 			 "Cannot enable project quota enforcement.");
2098 		return 0;
2099 	}
2100 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2101 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2102 	if (usr_qf_name || grp_qf_name) {
2103 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2104 			clear_opt(sb, USRQUOTA);
2105 
2106 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2107 			clear_opt(sb, GRPQUOTA);
2108 
2109 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2110 			ext4_msg(sb, KERN_ERR, "old and new quota "
2111 					"format mixing");
2112 			return 0;
2113 		}
2114 
2115 		if (!sbi->s_jquota_fmt) {
2116 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2117 					"not specified");
2118 			return 0;
2119 		}
2120 	}
2121 #endif
2122 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2123 		int blocksize =
2124 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2125 
2126 		if (blocksize < PAGE_SIZE) {
2127 			ext4_msg(sb, KERN_ERR, "can't mount with "
2128 				 "dioread_nolock if block size != PAGE_SIZE");
2129 			return 0;
2130 		}
2131 	}
2132 	return 1;
2133 }
2134 
2135 static inline void ext4_show_quota_options(struct seq_file *seq,
2136 					   struct super_block *sb)
2137 {
2138 #if defined(CONFIG_QUOTA)
2139 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2140 	char *usr_qf_name, *grp_qf_name;
2141 
2142 	if (sbi->s_jquota_fmt) {
2143 		char *fmtname = "";
2144 
2145 		switch (sbi->s_jquota_fmt) {
2146 		case QFMT_VFS_OLD:
2147 			fmtname = "vfsold";
2148 			break;
2149 		case QFMT_VFS_V0:
2150 			fmtname = "vfsv0";
2151 			break;
2152 		case QFMT_VFS_V1:
2153 			fmtname = "vfsv1";
2154 			break;
2155 		}
2156 		seq_printf(seq, ",jqfmt=%s", fmtname);
2157 	}
2158 
2159 	rcu_read_lock();
2160 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2161 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2162 	if (usr_qf_name)
2163 		seq_show_option(seq, "usrjquota", usr_qf_name);
2164 	if (grp_qf_name)
2165 		seq_show_option(seq, "grpjquota", grp_qf_name);
2166 	rcu_read_unlock();
2167 #endif
2168 }
2169 
2170 static const char *token2str(int token)
2171 {
2172 	const struct match_token *t;
2173 
2174 	for (t = tokens; t->token != Opt_err; t++)
2175 		if (t->token == token && !strchr(t->pattern, '='))
2176 			break;
2177 	return t->pattern;
2178 }
2179 
2180 /*
2181  * Show an option if
2182  *  - it's set to a non-default value OR
2183  *  - if the per-sb default is different from the global default
2184  */
2185 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2186 			      int nodefs)
2187 {
2188 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2189 	struct ext4_super_block *es = sbi->s_es;
2190 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2191 	const struct mount_opts *m;
2192 	char sep = nodefs ? '\n' : ',';
2193 
2194 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2195 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2196 
2197 	if (sbi->s_sb_block != 1)
2198 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2199 
2200 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2201 		int want_set = m->flags & MOPT_SET;
2202 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2203 		    (m->flags & MOPT_CLEAR_ERR))
2204 			continue;
2205 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2206 			continue; /* skip if same as the default */
2207 		if ((want_set &&
2208 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2209 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2210 			continue; /* select Opt_noFoo vs Opt_Foo */
2211 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2212 	}
2213 
2214 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2215 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2216 		SEQ_OPTS_PRINT("resuid=%u",
2217 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2218 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2219 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2220 		SEQ_OPTS_PRINT("resgid=%u",
2221 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2222 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2223 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2224 		SEQ_OPTS_PUTS("errors=remount-ro");
2225 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2226 		SEQ_OPTS_PUTS("errors=continue");
2227 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2228 		SEQ_OPTS_PUTS("errors=panic");
2229 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2230 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2231 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2232 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2233 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2234 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2235 	if (sb->s_flags & SB_I_VERSION)
2236 		SEQ_OPTS_PUTS("i_version");
2237 	if (nodefs || sbi->s_stripe)
2238 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2239 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2240 			(sbi->s_mount_opt ^ def_mount_opt)) {
2241 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2242 			SEQ_OPTS_PUTS("data=journal");
2243 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2244 			SEQ_OPTS_PUTS("data=ordered");
2245 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2246 			SEQ_OPTS_PUTS("data=writeback");
2247 	}
2248 	if (nodefs ||
2249 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2250 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2251 			       sbi->s_inode_readahead_blks);
2252 
2253 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2254 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2255 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2256 	if (nodefs || sbi->s_max_dir_size_kb)
2257 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2258 	if (test_opt(sb, DATA_ERR_ABORT))
2259 		SEQ_OPTS_PUTS("data_err=abort");
2260 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2261 		SEQ_OPTS_PUTS("test_dummy_encryption");
2262 
2263 	ext4_show_quota_options(seq, sb);
2264 	return 0;
2265 }
2266 
2267 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2268 {
2269 	return _ext4_show_options(seq, root->d_sb, 0);
2270 }
2271 
2272 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2273 {
2274 	struct super_block *sb = seq->private;
2275 	int rc;
2276 
2277 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2278 	rc = _ext4_show_options(seq, sb, 1);
2279 	seq_puts(seq, "\n");
2280 	return rc;
2281 }
2282 
2283 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2284 			    int read_only)
2285 {
2286 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2287 	int err = 0;
2288 
2289 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2290 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2291 			 "forcing read-only mode");
2292 		err = -EROFS;
2293 	}
2294 	if (read_only)
2295 		goto done;
2296 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2297 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2298 			 "running e2fsck is recommended");
2299 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2300 		ext4_msg(sb, KERN_WARNING,
2301 			 "warning: mounting fs with errors, "
2302 			 "running e2fsck is recommended");
2303 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2304 		 le16_to_cpu(es->s_mnt_count) >=
2305 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2306 		ext4_msg(sb, KERN_WARNING,
2307 			 "warning: maximal mount count reached, "
2308 			 "running e2fsck is recommended");
2309 	else if (le32_to_cpu(es->s_checkinterval) &&
2310 		 (ext4_get_tstamp(es, s_lastcheck) +
2311 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2312 		ext4_msg(sb, KERN_WARNING,
2313 			 "warning: checktime reached, "
2314 			 "running e2fsck is recommended");
2315 	if (!sbi->s_journal)
2316 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2317 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2318 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2319 	le16_add_cpu(&es->s_mnt_count, 1);
2320 	ext4_update_tstamp(es, s_mtime);
2321 	if (sbi->s_journal)
2322 		ext4_set_feature_journal_needs_recovery(sb);
2323 
2324 	err = ext4_commit_super(sb, 1);
2325 done:
2326 	if (test_opt(sb, DEBUG))
2327 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2328 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2329 			sb->s_blocksize,
2330 			sbi->s_groups_count,
2331 			EXT4_BLOCKS_PER_GROUP(sb),
2332 			EXT4_INODES_PER_GROUP(sb),
2333 			sbi->s_mount_opt, sbi->s_mount_opt2);
2334 
2335 	cleancache_init_fs(sb);
2336 	return err;
2337 }
2338 
2339 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2340 {
2341 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2342 	struct flex_groups *new_groups;
2343 	int size;
2344 
2345 	if (!sbi->s_log_groups_per_flex)
2346 		return 0;
2347 
2348 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2349 	if (size <= sbi->s_flex_groups_allocated)
2350 		return 0;
2351 
2352 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2353 	new_groups = kvzalloc(size, GFP_KERNEL);
2354 	if (!new_groups) {
2355 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2356 			 size / (int) sizeof(struct flex_groups));
2357 		return -ENOMEM;
2358 	}
2359 
2360 	if (sbi->s_flex_groups) {
2361 		memcpy(new_groups, sbi->s_flex_groups,
2362 		       (sbi->s_flex_groups_allocated *
2363 			sizeof(struct flex_groups)));
2364 		kvfree(sbi->s_flex_groups);
2365 	}
2366 	sbi->s_flex_groups = new_groups;
2367 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2368 	return 0;
2369 }
2370 
2371 static int ext4_fill_flex_info(struct super_block *sb)
2372 {
2373 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2374 	struct ext4_group_desc *gdp = NULL;
2375 	ext4_group_t flex_group;
2376 	int i, err;
2377 
2378 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2379 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2380 		sbi->s_log_groups_per_flex = 0;
2381 		return 1;
2382 	}
2383 
2384 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2385 	if (err)
2386 		goto failed;
2387 
2388 	for (i = 0; i < sbi->s_groups_count; i++) {
2389 		gdp = ext4_get_group_desc(sb, i, NULL);
2390 
2391 		flex_group = ext4_flex_group(sbi, i);
2392 		atomic_add(ext4_free_inodes_count(sb, gdp),
2393 			   &sbi->s_flex_groups[flex_group].free_inodes);
2394 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2395 			     &sbi->s_flex_groups[flex_group].free_clusters);
2396 		atomic_add(ext4_used_dirs_count(sb, gdp),
2397 			   &sbi->s_flex_groups[flex_group].used_dirs);
2398 	}
2399 
2400 	return 1;
2401 failed:
2402 	return 0;
2403 }
2404 
2405 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2406 				   struct ext4_group_desc *gdp)
2407 {
2408 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2409 	__u16 crc = 0;
2410 	__le32 le_group = cpu_to_le32(block_group);
2411 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2412 
2413 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2414 		/* Use new metadata_csum algorithm */
2415 		__u32 csum32;
2416 		__u16 dummy_csum = 0;
2417 
2418 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2419 				     sizeof(le_group));
2420 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2421 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2422 				     sizeof(dummy_csum));
2423 		offset += sizeof(dummy_csum);
2424 		if (offset < sbi->s_desc_size)
2425 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2426 					     sbi->s_desc_size - offset);
2427 
2428 		crc = csum32 & 0xFFFF;
2429 		goto out;
2430 	}
2431 
2432 	/* old crc16 code */
2433 	if (!ext4_has_feature_gdt_csum(sb))
2434 		return 0;
2435 
2436 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2437 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2438 	crc = crc16(crc, (__u8 *)gdp, offset);
2439 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2440 	/* for checksum of struct ext4_group_desc do the rest...*/
2441 	if (ext4_has_feature_64bit(sb) &&
2442 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2443 		crc = crc16(crc, (__u8 *)gdp + offset,
2444 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2445 				offset);
2446 
2447 out:
2448 	return cpu_to_le16(crc);
2449 }
2450 
2451 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2452 				struct ext4_group_desc *gdp)
2453 {
2454 	if (ext4_has_group_desc_csum(sb) &&
2455 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2456 		return 0;
2457 
2458 	return 1;
2459 }
2460 
2461 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2462 			      struct ext4_group_desc *gdp)
2463 {
2464 	if (!ext4_has_group_desc_csum(sb))
2465 		return;
2466 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2467 }
2468 
2469 /* Called at mount-time, super-block is locked */
2470 static int ext4_check_descriptors(struct super_block *sb,
2471 				  ext4_fsblk_t sb_block,
2472 				  ext4_group_t *first_not_zeroed)
2473 {
2474 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2475 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2476 	ext4_fsblk_t last_block;
2477 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2478 	ext4_fsblk_t block_bitmap;
2479 	ext4_fsblk_t inode_bitmap;
2480 	ext4_fsblk_t inode_table;
2481 	int flexbg_flag = 0;
2482 	ext4_group_t i, grp = sbi->s_groups_count;
2483 
2484 	if (ext4_has_feature_flex_bg(sb))
2485 		flexbg_flag = 1;
2486 
2487 	ext4_debug("Checking group descriptors");
2488 
2489 	for (i = 0; i < sbi->s_groups_count; i++) {
2490 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2491 
2492 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2493 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2494 		else
2495 			last_block = first_block +
2496 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2497 
2498 		if ((grp == sbi->s_groups_count) &&
2499 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2500 			grp = i;
2501 
2502 		block_bitmap = ext4_block_bitmap(sb, gdp);
2503 		if (block_bitmap == sb_block) {
2504 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2505 				 "Block bitmap for group %u overlaps "
2506 				 "superblock", i);
2507 			if (!sb_rdonly(sb))
2508 				return 0;
2509 		}
2510 		if (block_bitmap >= sb_block + 1 &&
2511 		    block_bitmap <= last_bg_block) {
2512 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2513 				 "Block bitmap for group %u overlaps "
2514 				 "block group descriptors", i);
2515 			if (!sb_rdonly(sb))
2516 				return 0;
2517 		}
2518 		if (block_bitmap < first_block || block_bitmap > last_block) {
2519 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2520 			       "Block bitmap for group %u not in group "
2521 			       "(block %llu)!", i, block_bitmap);
2522 			return 0;
2523 		}
2524 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2525 		if (inode_bitmap == sb_block) {
2526 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2527 				 "Inode bitmap for group %u overlaps "
2528 				 "superblock", i);
2529 			if (!sb_rdonly(sb))
2530 				return 0;
2531 		}
2532 		if (inode_bitmap >= sb_block + 1 &&
2533 		    inode_bitmap <= last_bg_block) {
2534 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2535 				 "Inode bitmap for group %u overlaps "
2536 				 "block group descriptors", i);
2537 			if (!sb_rdonly(sb))
2538 				return 0;
2539 		}
2540 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2541 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2542 			       "Inode bitmap for group %u not in group "
2543 			       "(block %llu)!", i, inode_bitmap);
2544 			return 0;
2545 		}
2546 		inode_table = ext4_inode_table(sb, gdp);
2547 		if (inode_table == sb_block) {
2548 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2549 				 "Inode table for group %u overlaps "
2550 				 "superblock", i);
2551 			if (!sb_rdonly(sb))
2552 				return 0;
2553 		}
2554 		if (inode_table >= sb_block + 1 &&
2555 		    inode_table <= last_bg_block) {
2556 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2557 				 "Inode table for group %u overlaps "
2558 				 "block group descriptors", i);
2559 			if (!sb_rdonly(sb))
2560 				return 0;
2561 		}
2562 		if (inode_table < first_block ||
2563 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2564 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2565 			       "Inode table for group %u not in group "
2566 			       "(block %llu)!", i, inode_table);
2567 			return 0;
2568 		}
2569 		ext4_lock_group(sb, i);
2570 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2571 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2572 				 "Checksum for group %u failed (%u!=%u)",
2573 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2574 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2575 			if (!sb_rdonly(sb)) {
2576 				ext4_unlock_group(sb, i);
2577 				return 0;
2578 			}
2579 		}
2580 		ext4_unlock_group(sb, i);
2581 		if (!flexbg_flag)
2582 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2583 	}
2584 	if (NULL != first_not_zeroed)
2585 		*first_not_zeroed = grp;
2586 	return 1;
2587 }
2588 
2589 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2590  * the superblock) which were deleted from all directories, but held open by
2591  * a process at the time of a crash.  We walk the list and try to delete these
2592  * inodes at recovery time (only with a read-write filesystem).
2593  *
2594  * In order to keep the orphan inode chain consistent during traversal (in
2595  * case of crash during recovery), we link each inode into the superblock
2596  * orphan list_head and handle it the same way as an inode deletion during
2597  * normal operation (which journals the operations for us).
2598  *
2599  * We only do an iget() and an iput() on each inode, which is very safe if we
2600  * accidentally point at an in-use or already deleted inode.  The worst that
2601  * can happen in this case is that we get a "bit already cleared" message from
2602  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2603  * e2fsck was run on this filesystem, and it must have already done the orphan
2604  * inode cleanup for us, so we can safely abort without any further action.
2605  */
2606 static void ext4_orphan_cleanup(struct super_block *sb,
2607 				struct ext4_super_block *es)
2608 {
2609 	unsigned int s_flags = sb->s_flags;
2610 	int ret, nr_orphans = 0, nr_truncates = 0;
2611 #ifdef CONFIG_QUOTA
2612 	int quota_update = 0;
2613 	int i;
2614 #endif
2615 	if (!es->s_last_orphan) {
2616 		jbd_debug(4, "no orphan inodes to clean up\n");
2617 		return;
2618 	}
2619 
2620 	if (bdev_read_only(sb->s_bdev)) {
2621 		ext4_msg(sb, KERN_ERR, "write access "
2622 			"unavailable, skipping orphan cleanup");
2623 		return;
2624 	}
2625 
2626 	/* Check if feature set would not allow a r/w mount */
2627 	if (!ext4_feature_set_ok(sb, 0)) {
2628 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2629 			 "unknown ROCOMPAT features");
2630 		return;
2631 	}
2632 
2633 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2634 		/* don't clear list on RO mount w/ errors */
2635 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2636 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2637 				  "clearing orphan list.\n");
2638 			es->s_last_orphan = 0;
2639 		}
2640 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2641 		return;
2642 	}
2643 
2644 	if (s_flags & SB_RDONLY) {
2645 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2646 		sb->s_flags &= ~SB_RDONLY;
2647 	}
2648 #ifdef CONFIG_QUOTA
2649 	/* Needed for iput() to work correctly and not trash data */
2650 	sb->s_flags |= SB_ACTIVE;
2651 
2652 	/*
2653 	 * Turn on quotas which were not enabled for read-only mounts if
2654 	 * filesystem has quota feature, so that they are updated correctly.
2655 	 */
2656 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2657 		int ret = ext4_enable_quotas(sb);
2658 
2659 		if (!ret)
2660 			quota_update = 1;
2661 		else
2662 			ext4_msg(sb, KERN_ERR,
2663 				"Cannot turn on quotas: error %d", ret);
2664 	}
2665 
2666 	/* Turn on journaled quotas used for old sytle */
2667 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2668 		if (EXT4_SB(sb)->s_qf_names[i]) {
2669 			int ret = ext4_quota_on_mount(sb, i);
2670 
2671 			if (!ret)
2672 				quota_update = 1;
2673 			else
2674 				ext4_msg(sb, KERN_ERR,
2675 					"Cannot turn on journaled "
2676 					"quota: type %d: error %d", i, ret);
2677 		}
2678 	}
2679 #endif
2680 
2681 	while (es->s_last_orphan) {
2682 		struct inode *inode;
2683 
2684 		/*
2685 		 * We may have encountered an error during cleanup; if
2686 		 * so, skip the rest.
2687 		 */
2688 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2689 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2690 			es->s_last_orphan = 0;
2691 			break;
2692 		}
2693 
2694 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2695 		if (IS_ERR(inode)) {
2696 			es->s_last_orphan = 0;
2697 			break;
2698 		}
2699 
2700 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2701 		dquot_initialize(inode);
2702 		if (inode->i_nlink) {
2703 			if (test_opt(sb, DEBUG))
2704 				ext4_msg(sb, KERN_DEBUG,
2705 					"%s: truncating inode %lu to %lld bytes",
2706 					__func__, inode->i_ino, inode->i_size);
2707 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2708 				  inode->i_ino, inode->i_size);
2709 			inode_lock(inode);
2710 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2711 			ret = ext4_truncate(inode);
2712 			if (ret)
2713 				ext4_std_error(inode->i_sb, ret);
2714 			inode_unlock(inode);
2715 			nr_truncates++;
2716 		} else {
2717 			if (test_opt(sb, DEBUG))
2718 				ext4_msg(sb, KERN_DEBUG,
2719 					"%s: deleting unreferenced inode %lu",
2720 					__func__, inode->i_ino);
2721 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2722 				  inode->i_ino);
2723 			nr_orphans++;
2724 		}
2725 		iput(inode);  /* The delete magic happens here! */
2726 	}
2727 
2728 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2729 
2730 	if (nr_orphans)
2731 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2732 		       PLURAL(nr_orphans));
2733 	if (nr_truncates)
2734 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2735 		       PLURAL(nr_truncates));
2736 #ifdef CONFIG_QUOTA
2737 	/* Turn off quotas if they were enabled for orphan cleanup */
2738 	if (quota_update) {
2739 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2740 			if (sb_dqopt(sb)->files[i])
2741 				dquot_quota_off(sb, i);
2742 		}
2743 	}
2744 #endif
2745 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2746 }
2747 
2748 /*
2749  * Maximal extent format file size.
2750  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2751  * extent format containers, within a sector_t, and within i_blocks
2752  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2753  * so that won't be a limiting factor.
2754  *
2755  * However there is other limiting factor. We do store extents in the form
2756  * of starting block and length, hence the resulting length of the extent
2757  * covering maximum file size must fit into on-disk format containers as
2758  * well. Given that length is always by 1 unit bigger than max unit (because
2759  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2760  *
2761  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2762  */
2763 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2764 {
2765 	loff_t res;
2766 	loff_t upper_limit = MAX_LFS_FILESIZE;
2767 
2768 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2769 
2770 	if (!has_huge_files) {
2771 		upper_limit = (1LL << 32) - 1;
2772 
2773 		/* total blocks in file system block size */
2774 		upper_limit >>= (blkbits - 9);
2775 		upper_limit <<= blkbits;
2776 	}
2777 
2778 	/*
2779 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2780 	 * by one fs block, so ee_len can cover the extent of maximum file
2781 	 * size
2782 	 */
2783 	res = (1LL << 32) - 1;
2784 	res <<= blkbits;
2785 
2786 	/* Sanity check against vm- & vfs- imposed limits */
2787 	if (res > upper_limit)
2788 		res = upper_limit;
2789 
2790 	return res;
2791 }
2792 
2793 /*
2794  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2795  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2796  * We need to be 1 filesystem block less than the 2^48 sector limit.
2797  */
2798 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2799 {
2800 	loff_t res = EXT4_NDIR_BLOCKS;
2801 	int meta_blocks;
2802 	loff_t upper_limit;
2803 	/* This is calculated to be the largest file size for a dense, block
2804 	 * mapped file such that the file's total number of 512-byte sectors,
2805 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2806 	 *
2807 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2808 	 * number of 512-byte sectors of the file.
2809 	 */
2810 
2811 	if (!has_huge_files) {
2812 		/*
2813 		 * !has_huge_files or implies that the inode i_block field
2814 		 * represents total file blocks in 2^32 512-byte sectors ==
2815 		 * size of vfs inode i_blocks * 8
2816 		 */
2817 		upper_limit = (1LL << 32) - 1;
2818 
2819 		/* total blocks in file system block size */
2820 		upper_limit >>= (bits - 9);
2821 
2822 	} else {
2823 		/*
2824 		 * We use 48 bit ext4_inode i_blocks
2825 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2826 		 * represent total number of blocks in
2827 		 * file system block size
2828 		 */
2829 		upper_limit = (1LL << 48) - 1;
2830 
2831 	}
2832 
2833 	/* indirect blocks */
2834 	meta_blocks = 1;
2835 	/* double indirect blocks */
2836 	meta_blocks += 1 + (1LL << (bits-2));
2837 	/* tripple indirect blocks */
2838 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2839 
2840 	upper_limit -= meta_blocks;
2841 	upper_limit <<= bits;
2842 
2843 	res += 1LL << (bits-2);
2844 	res += 1LL << (2*(bits-2));
2845 	res += 1LL << (3*(bits-2));
2846 	res <<= bits;
2847 	if (res > upper_limit)
2848 		res = upper_limit;
2849 
2850 	if (res > MAX_LFS_FILESIZE)
2851 		res = MAX_LFS_FILESIZE;
2852 
2853 	return res;
2854 }
2855 
2856 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2857 				   ext4_fsblk_t logical_sb_block, int nr)
2858 {
2859 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2860 	ext4_group_t bg, first_meta_bg;
2861 	int has_super = 0;
2862 
2863 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2864 
2865 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2866 		return logical_sb_block + nr + 1;
2867 	bg = sbi->s_desc_per_block * nr;
2868 	if (ext4_bg_has_super(sb, bg))
2869 		has_super = 1;
2870 
2871 	/*
2872 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2873 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2874 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2875 	 * compensate.
2876 	 */
2877 	if (sb->s_blocksize == 1024 && nr == 0 &&
2878 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2879 		has_super++;
2880 
2881 	return (has_super + ext4_group_first_block_no(sb, bg));
2882 }
2883 
2884 /**
2885  * ext4_get_stripe_size: Get the stripe size.
2886  * @sbi: In memory super block info
2887  *
2888  * If we have specified it via mount option, then
2889  * use the mount option value. If the value specified at mount time is
2890  * greater than the blocks per group use the super block value.
2891  * If the super block value is greater than blocks per group return 0.
2892  * Allocator needs it be less than blocks per group.
2893  *
2894  */
2895 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2896 {
2897 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2898 	unsigned long stripe_width =
2899 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2900 	int ret;
2901 
2902 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2903 		ret = sbi->s_stripe;
2904 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2905 		ret = stripe_width;
2906 	else if (stride && stride <= sbi->s_blocks_per_group)
2907 		ret = stride;
2908 	else
2909 		ret = 0;
2910 
2911 	/*
2912 	 * If the stripe width is 1, this makes no sense and
2913 	 * we set it to 0 to turn off stripe handling code.
2914 	 */
2915 	if (ret <= 1)
2916 		ret = 0;
2917 
2918 	return ret;
2919 }
2920 
2921 /*
2922  * Check whether this filesystem can be mounted based on
2923  * the features present and the RDONLY/RDWR mount requested.
2924  * Returns 1 if this filesystem can be mounted as requested,
2925  * 0 if it cannot be.
2926  */
2927 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2928 {
2929 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2930 		ext4_msg(sb, KERN_ERR,
2931 			"Couldn't mount because of "
2932 			"unsupported optional features (%x)",
2933 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2934 			~EXT4_FEATURE_INCOMPAT_SUPP));
2935 		return 0;
2936 	}
2937 
2938 #ifndef CONFIG_UNICODE
2939 	if (ext4_has_feature_casefold(sb)) {
2940 		ext4_msg(sb, KERN_ERR,
2941 			 "Filesystem with casefold feature cannot be "
2942 			 "mounted without CONFIG_UNICODE");
2943 		return 0;
2944 	}
2945 #endif
2946 
2947 	if (readonly)
2948 		return 1;
2949 
2950 	if (ext4_has_feature_readonly(sb)) {
2951 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2952 		sb->s_flags |= SB_RDONLY;
2953 		return 1;
2954 	}
2955 
2956 	/* Check that feature set is OK for a read-write mount */
2957 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2958 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2959 			 "unsupported optional features (%x)",
2960 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2961 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2962 		return 0;
2963 	}
2964 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2965 		ext4_msg(sb, KERN_ERR,
2966 			 "Can't support bigalloc feature without "
2967 			 "extents feature\n");
2968 		return 0;
2969 	}
2970 
2971 #ifndef CONFIG_QUOTA
2972 	if (ext4_has_feature_quota(sb) && !readonly) {
2973 		ext4_msg(sb, KERN_ERR,
2974 			 "Filesystem with quota feature cannot be mounted RDWR "
2975 			 "without CONFIG_QUOTA");
2976 		return 0;
2977 	}
2978 	if (ext4_has_feature_project(sb) && !readonly) {
2979 		ext4_msg(sb, KERN_ERR,
2980 			 "Filesystem with project quota feature cannot be mounted RDWR "
2981 			 "without CONFIG_QUOTA");
2982 		return 0;
2983 	}
2984 #endif  /* CONFIG_QUOTA */
2985 	return 1;
2986 }
2987 
2988 /*
2989  * This function is called once a day if we have errors logged
2990  * on the file system
2991  */
2992 static void print_daily_error_info(struct timer_list *t)
2993 {
2994 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2995 	struct super_block *sb = sbi->s_sb;
2996 	struct ext4_super_block *es = sbi->s_es;
2997 
2998 	if (es->s_error_count)
2999 		/* fsck newer than v1.41.13 is needed to clean this condition. */
3000 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
3001 			 le32_to_cpu(es->s_error_count));
3002 	if (es->s_first_error_time) {
3003 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
3004 		       sb->s_id,
3005 		       ext4_get_tstamp(es, s_first_error_time),
3006 		       (int) sizeof(es->s_first_error_func),
3007 		       es->s_first_error_func,
3008 		       le32_to_cpu(es->s_first_error_line));
3009 		if (es->s_first_error_ino)
3010 			printk(KERN_CONT ": inode %u",
3011 			       le32_to_cpu(es->s_first_error_ino));
3012 		if (es->s_first_error_block)
3013 			printk(KERN_CONT ": block %llu", (unsigned long long)
3014 			       le64_to_cpu(es->s_first_error_block));
3015 		printk(KERN_CONT "\n");
3016 	}
3017 	if (es->s_last_error_time) {
3018 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3019 		       sb->s_id,
3020 		       ext4_get_tstamp(es, s_last_error_time),
3021 		       (int) sizeof(es->s_last_error_func),
3022 		       es->s_last_error_func,
3023 		       le32_to_cpu(es->s_last_error_line));
3024 		if (es->s_last_error_ino)
3025 			printk(KERN_CONT ": inode %u",
3026 			       le32_to_cpu(es->s_last_error_ino));
3027 		if (es->s_last_error_block)
3028 			printk(KERN_CONT ": block %llu", (unsigned long long)
3029 			       le64_to_cpu(es->s_last_error_block));
3030 		printk(KERN_CONT "\n");
3031 	}
3032 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3033 }
3034 
3035 /* Find next suitable group and run ext4_init_inode_table */
3036 static int ext4_run_li_request(struct ext4_li_request *elr)
3037 {
3038 	struct ext4_group_desc *gdp = NULL;
3039 	ext4_group_t group, ngroups;
3040 	struct super_block *sb;
3041 	unsigned long timeout = 0;
3042 	int ret = 0;
3043 
3044 	sb = elr->lr_super;
3045 	ngroups = EXT4_SB(sb)->s_groups_count;
3046 
3047 	for (group = elr->lr_next_group; group < ngroups; group++) {
3048 		gdp = ext4_get_group_desc(sb, group, NULL);
3049 		if (!gdp) {
3050 			ret = 1;
3051 			break;
3052 		}
3053 
3054 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3055 			break;
3056 	}
3057 
3058 	if (group >= ngroups)
3059 		ret = 1;
3060 
3061 	if (!ret) {
3062 		timeout = jiffies;
3063 		ret = ext4_init_inode_table(sb, group,
3064 					    elr->lr_timeout ? 0 : 1);
3065 		if (elr->lr_timeout == 0) {
3066 			timeout = (jiffies - timeout) *
3067 				  elr->lr_sbi->s_li_wait_mult;
3068 			elr->lr_timeout = timeout;
3069 		}
3070 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3071 		elr->lr_next_group = group + 1;
3072 	}
3073 	return ret;
3074 }
3075 
3076 /*
3077  * Remove lr_request from the list_request and free the
3078  * request structure. Should be called with li_list_mtx held
3079  */
3080 static void ext4_remove_li_request(struct ext4_li_request *elr)
3081 {
3082 	struct ext4_sb_info *sbi;
3083 
3084 	if (!elr)
3085 		return;
3086 
3087 	sbi = elr->lr_sbi;
3088 
3089 	list_del(&elr->lr_request);
3090 	sbi->s_li_request = NULL;
3091 	kfree(elr);
3092 }
3093 
3094 static void ext4_unregister_li_request(struct super_block *sb)
3095 {
3096 	mutex_lock(&ext4_li_mtx);
3097 	if (!ext4_li_info) {
3098 		mutex_unlock(&ext4_li_mtx);
3099 		return;
3100 	}
3101 
3102 	mutex_lock(&ext4_li_info->li_list_mtx);
3103 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3104 	mutex_unlock(&ext4_li_info->li_list_mtx);
3105 	mutex_unlock(&ext4_li_mtx);
3106 }
3107 
3108 static struct task_struct *ext4_lazyinit_task;
3109 
3110 /*
3111  * This is the function where ext4lazyinit thread lives. It walks
3112  * through the request list searching for next scheduled filesystem.
3113  * When such a fs is found, run the lazy initialization request
3114  * (ext4_rn_li_request) and keep track of the time spend in this
3115  * function. Based on that time we compute next schedule time of
3116  * the request. When walking through the list is complete, compute
3117  * next waking time and put itself into sleep.
3118  */
3119 static int ext4_lazyinit_thread(void *arg)
3120 {
3121 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3122 	struct list_head *pos, *n;
3123 	struct ext4_li_request *elr;
3124 	unsigned long next_wakeup, cur;
3125 
3126 	BUG_ON(NULL == eli);
3127 
3128 cont_thread:
3129 	while (true) {
3130 		next_wakeup = MAX_JIFFY_OFFSET;
3131 
3132 		mutex_lock(&eli->li_list_mtx);
3133 		if (list_empty(&eli->li_request_list)) {
3134 			mutex_unlock(&eli->li_list_mtx);
3135 			goto exit_thread;
3136 		}
3137 		list_for_each_safe(pos, n, &eli->li_request_list) {
3138 			int err = 0;
3139 			int progress = 0;
3140 			elr = list_entry(pos, struct ext4_li_request,
3141 					 lr_request);
3142 
3143 			if (time_before(jiffies, elr->lr_next_sched)) {
3144 				if (time_before(elr->lr_next_sched, next_wakeup))
3145 					next_wakeup = elr->lr_next_sched;
3146 				continue;
3147 			}
3148 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3149 				if (sb_start_write_trylock(elr->lr_super)) {
3150 					progress = 1;
3151 					/*
3152 					 * We hold sb->s_umount, sb can not
3153 					 * be removed from the list, it is
3154 					 * now safe to drop li_list_mtx
3155 					 */
3156 					mutex_unlock(&eli->li_list_mtx);
3157 					err = ext4_run_li_request(elr);
3158 					sb_end_write(elr->lr_super);
3159 					mutex_lock(&eli->li_list_mtx);
3160 					n = pos->next;
3161 				}
3162 				up_read((&elr->lr_super->s_umount));
3163 			}
3164 			/* error, remove the lazy_init job */
3165 			if (err) {
3166 				ext4_remove_li_request(elr);
3167 				continue;
3168 			}
3169 			if (!progress) {
3170 				elr->lr_next_sched = jiffies +
3171 					(prandom_u32()
3172 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3173 			}
3174 			if (time_before(elr->lr_next_sched, next_wakeup))
3175 				next_wakeup = elr->lr_next_sched;
3176 		}
3177 		mutex_unlock(&eli->li_list_mtx);
3178 
3179 		try_to_freeze();
3180 
3181 		cur = jiffies;
3182 		if ((time_after_eq(cur, next_wakeup)) ||
3183 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3184 			cond_resched();
3185 			continue;
3186 		}
3187 
3188 		schedule_timeout_interruptible(next_wakeup - cur);
3189 
3190 		if (kthread_should_stop()) {
3191 			ext4_clear_request_list();
3192 			goto exit_thread;
3193 		}
3194 	}
3195 
3196 exit_thread:
3197 	/*
3198 	 * It looks like the request list is empty, but we need
3199 	 * to check it under the li_list_mtx lock, to prevent any
3200 	 * additions into it, and of course we should lock ext4_li_mtx
3201 	 * to atomically free the list and ext4_li_info, because at
3202 	 * this point another ext4 filesystem could be registering
3203 	 * new one.
3204 	 */
3205 	mutex_lock(&ext4_li_mtx);
3206 	mutex_lock(&eli->li_list_mtx);
3207 	if (!list_empty(&eli->li_request_list)) {
3208 		mutex_unlock(&eli->li_list_mtx);
3209 		mutex_unlock(&ext4_li_mtx);
3210 		goto cont_thread;
3211 	}
3212 	mutex_unlock(&eli->li_list_mtx);
3213 	kfree(ext4_li_info);
3214 	ext4_li_info = NULL;
3215 	mutex_unlock(&ext4_li_mtx);
3216 
3217 	return 0;
3218 }
3219 
3220 static void ext4_clear_request_list(void)
3221 {
3222 	struct list_head *pos, *n;
3223 	struct ext4_li_request *elr;
3224 
3225 	mutex_lock(&ext4_li_info->li_list_mtx);
3226 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3227 		elr = list_entry(pos, struct ext4_li_request,
3228 				 lr_request);
3229 		ext4_remove_li_request(elr);
3230 	}
3231 	mutex_unlock(&ext4_li_info->li_list_mtx);
3232 }
3233 
3234 static int ext4_run_lazyinit_thread(void)
3235 {
3236 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3237 					 ext4_li_info, "ext4lazyinit");
3238 	if (IS_ERR(ext4_lazyinit_task)) {
3239 		int err = PTR_ERR(ext4_lazyinit_task);
3240 		ext4_clear_request_list();
3241 		kfree(ext4_li_info);
3242 		ext4_li_info = NULL;
3243 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3244 				 "initialization thread\n",
3245 				 err);
3246 		return err;
3247 	}
3248 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3249 	return 0;
3250 }
3251 
3252 /*
3253  * Check whether it make sense to run itable init. thread or not.
3254  * If there is at least one uninitialized inode table, return
3255  * corresponding group number, else the loop goes through all
3256  * groups and return total number of groups.
3257  */
3258 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3259 {
3260 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3261 	struct ext4_group_desc *gdp = NULL;
3262 
3263 	if (!ext4_has_group_desc_csum(sb))
3264 		return ngroups;
3265 
3266 	for (group = 0; group < ngroups; group++) {
3267 		gdp = ext4_get_group_desc(sb, group, NULL);
3268 		if (!gdp)
3269 			continue;
3270 
3271 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3272 			break;
3273 	}
3274 
3275 	return group;
3276 }
3277 
3278 static int ext4_li_info_new(void)
3279 {
3280 	struct ext4_lazy_init *eli = NULL;
3281 
3282 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3283 	if (!eli)
3284 		return -ENOMEM;
3285 
3286 	INIT_LIST_HEAD(&eli->li_request_list);
3287 	mutex_init(&eli->li_list_mtx);
3288 
3289 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3290 
3291 	ext4_li_info = eli;
3292 
3293 	return 0;
3294 }
3295 
3296 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3297 					    ext4_group_t start)
3298 {
3299 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3300 	struct ext4_li_request *elr;
3301 
3302 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3303 	if (!elr)
3304 		return NULL;
3305 
3306 	elr->lr_super = sb;
3307 	elr->lr_sbi = sbi;
3308 	elr->lr_next_group = start;
3309 
3310 	/*
3311 	 * Randomize first schedule time of the request to
3312 	 * spread the inode table initialization requests
3313 	 * better.
3314 	 */
3315 	elr->lr_next_sched = jiffies + (prandom_u32() %
3316 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3317 	return elr;
3318 }
3319 
3320 int ext4_register_li_request(struct super_block *sb,
3321 			     ext4_group_t first_not_zeroed)
3322 {
3323 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3324 	struct ext4_li_request *elr = NULL;
3325 	ext4_group_t ngroups = sbi->s_groups_count;
3326 	int ret = 0;
3327 
3328 	mutex_lock(&ext4_li_mtx);
3329 	if (sbi->s_li_request != NULL) {
3330 		/*
3331 		 * Reset timeout so it can be computed again, because
3332 		 * s_li_wait_mult might have changed.
3333 		 */
3334 		sbi->s_li_request->lr_timeout = 0;
3335 		goto out;
3336 	}
3337 
3338 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3339 	    !test_opt(sb, INIT_INODE_TABLE))
3340 		goto out;
3341 
3342 	elr = ext4_li_request_new(sb, first_not_zeroed);
3343 	if (!elr) {
3344 		ret = -ENOMEM;
3345 		goto out;
3346 	}
3347 
3348 	if (NULL == ext4_li_info) {
3349 		ret = ext4_li_info_new();
3350 		if (ret)
3351 			goto out;
3352 	}
3353 
3354 	mutex_lock(&ext4_li_info->li_list_mtx);
3355 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3356 	mutex_unlock(&ext4_li_info->li_list_mtx);
3357 
3358 	sbi->s_li_request = elr;
3359 	/*
3360 	 * set elr to NULL here since it has been inserted to
3361 	 * the request_list and the removal and free of it is
3362 	 * handled by ext4_clear_request_list from now on.
3363 	 */
3364 	elr = NULL;
3365 
3366 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3367 		ret = ext4_run_lazyinit_thread();
3368 		if (ret)
3369 			goto out;
3370 	}
3371 out:
3372 	mutex_unlock(&ext4_li_mtx);
3373 	if (ret)
3374 		kfree(elr);
3375 	return ret;
3376 }
3377 
3378 /*
3379  * We do not need to lock anything since this is called on
3380  * module unload.
3381  */
3382 static void ext4_destroy_lazyinit_thread(void)
3383 {
3384 	/*
3385 	 * If thread exited earlier
3386 	 * there's nothing to be done.
3387 	 */
3388 	if (!ext4_li_info || !ext4_lazyinit_task)
3389 		return;
3390 
3391 	kthread_stop(ext4_lazyinit_task);
3392 }
3393 
3394 static int set_journal_csum_feature_set(struct super_block *sb)
3395 {
3396 	int ret = 1;
3397 	int compat, incompat;
3398 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3399 
3400 	if (ext4_has_metadata_csum(sb)) {
3401 		/* journal checksum v3 */
3402 		compat = 0;
3403 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3404 	} else {
3405 		/* journal checksum v1 */
3406 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3407 		incompat = 0;
3408 	}
3409 
3410 	jbd2_journal_clear_features(sbi->s_journal,
3411 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3412 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3413 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3414 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3415 		ret = jbd2_journal_set_features(sbi->s_journal,
3416 				compat, 0,
3417 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3418 				incompat);
3419 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3420 		ret = jbd2_journal_set_features(sbi->s_journal,
3421 				compat, 0,
3422 				incompat);
3423 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3424 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3425 	} else {
3426 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3427 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3428 	}
3429 
3430 	return ret;
3431 }
3432 
3433 /*
3434  * Note: calculating the overhead so we can be compatible with
3435  * historical BSD practice is quite difficult in the face of
3436  * clusters/bigalloc.  This is because multiple metadata blocks from
3437  * different block group can end up in the same allocation cluster.
3438  * Calculating the exact overhead in the face of clustered allocation
3439  * requires either O(all block bitmaps) in memory or O(number of block
3440  * groups**2) in time.  We will still calculate the superblock for
3441  * older file systems --- and if we come across with a bigalloc file
3442  * system with zero in s_overhead_clusters the estimate will be close to
3443  * correct especially for very large cluster sizes --- but for newer
3444  * file systems, it's better to calculate this figure once at mkfs
3445  * time, and store it in the superblock.  If the superblock value is
3446  * present (even for non-bigalloc file systems), we will use it.
3447  */
3448 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3449 			  char *buf)
3450 {
3451 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3452 	struct ext4_group_desc	*gdp;
3453 	ext4_fsblk_t		first_block, last_block, b;
3454 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3455 	int			s, j, count = 0;
3456 
3457 	if (!ext4_has_feature_bigalloc(sb))
3458 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3459 			sbi->s_itb_per_group + 2);
3460 
3461 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3462 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3463 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3464 	for (i = 0; i < ngroups; i++) {
3465 		gdp = ext4_get_group_desc(sb, i, NULL);
3466 		b = ext4_block_bitmap(sb, gdp);
3467 		if (b >= first_block && b <= last_block) {
3468 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3469 			count++;
3470 		}
3471 		b = ext4_inode_bitmap(sb, gdp);
3472 		if (b >= first_block && b <= last_block) {
3473 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3474 			count++;
3475 		}
3476 		b = ext4_inode_table(sb, gdp);
3477 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3478 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3479 				int c = EXT4_B2C(sbi, b - first_block);
3480 				ext4_set_bit(c, buf);
3481 				count++;
3482 			}
3483 		if (i != grp)
3484 			continue;
3485 		s = 0;
3486 		if (ext4_bg_has_super(sb, grp)) {
3487 			ext4_set_bit(s++, buf);
3488 			count++;
3489 		}
3490 		j = ext4_bg_num_gdb(sb, grp);
3491 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3492 			ext4_error(sb, "Invalid number of block group "
3493 				   "descriptor blocks: %d", j);
3494 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3495 		}
3496 		count += j;
3497 		for (; j > 0; j--)
3498 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3499 	}
3500 	if (!count)
3501 		return 0;
3502 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3503 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3504 }
3505 
3506 /*
3507  * Compute the overhead and stash it in sbi->s_overhead
3508  */
3509 int ext4_calculate_overhead(struct super_block *sb)
3510 {
3511 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3512 	struct ext4_super_block *es = sbi->s_es;
3513 	struct inode *j_inode;
3514 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3515 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3516 	ext4_fsblk_t overhead = 0;
3517 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3518 
3519 	if (!buf)
3520 		return -ENOMEM;
3521 
3522 	/*
3523 	 * Compute the overhead (FS structures).  This is constant
3524 	 * for a given filesystem unless the number of block groups
3525 	 * changes so we cache the previous value until it does.
3526 	 */
3527 
3528 	/*
3529 	 * All of the blocks before first_data_block are overhead
3530 	 */
3531 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3532 
3533 	/*
3534 	 * Add the overhead found in each block group
3535 	 */
3536 	for (i = 0; i < ngroups; i++) {
3537 		int blks;
3538 
3539 		blks = count_overhead(sb, i, buf);
3540 		overhead += blks;
3541 		if (blks)
3542 			memset(buf, 0, PAGE_SIZE);
3543 		cond_resched();
3544 	}
3545 
3546 	/*
3547 	 * Add the internal journal blocks whether the journal has been
3548 	 * loaded or not
3549 	 */
3550 	if (sbi->s_journal && !sbi->journal_bdev)
3551 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3552 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3553 		j_inode = ext4_get_journal_inode(sb, j_inum);
3554 		if (j_inode) {
3555 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3556 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3557 			iput(j_inode);
3558 		} else {
3559 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3560 		}
3561 	}
3562 	sbi->s_overhead = overhead;
3563 	smp_wmb();
3564 	free_page((unsigned long) buf);
3565 	return 0;
3566 }
3567 
3568 static void ext4_clamp_want_extra_isize(struct super_block *sb)
3569 {
3570 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3571 	struct ext4_super_block *es = sbi->s_es;
3572 
3573 	/* determine the minimum size of new large inodes, if present */
3574 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
3575 	    sbi->s_want_extra_isize == 0) {
3576 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3577 						     EXT4_GOOD_OLD_INODE_SIZE;
3578 		if (ext4_has_feature_extra_isize(sb)) {
3579 			if (sbi->s_want_extra_isize <
3580 			    le16_to_cpu(es->s_want_extra_isize))
3581 				sbi->s_want_extra_isize =
3582 					le16_to_cpu(es->s_want_extra_isize);
3583 			if (sbi->s_want_extra_isize <
3584 			    le16_to_cpu(es->s_min_extra_isize))
3585 				sbi->s_want_extra_isize =
3586 					le16_to_cpu(es->s_min_extra_isize);
3587 		}
3588 	}
3589 	/* Check if enough inode space is available */
3590 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3591 							sbi->s_inode_size) {
3592 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3593 						       EXT4_GOOD_OLD_INODE_SIZE;
3594 		ext4_msg(sb, KERN_INFO,
3595 			 "required extra inode space not available");
3596 	}
3597 }
3598 
3599 static void ext4_set_resv_clusters(struct super_block *sb)
3600 {
3601 	ext4_fsblk_t resv_clusters;
3602 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3603 
3604 	/*
3605 	 * There's no need to reserve anything when we aren't using extents.
3606 	 * The space estimates are exact, there are no unwritten extents,
3607 	 * hole punching doesn't need new metadata... This is needed especially
3608 	 * to keep ext2/3 backward compatibility.
3609 	 */
3610 	if (!ext4_has_feature_extents(sb))
3611 		return;
3612 	/*
3613 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3614 	 * This should cover the situations where we can not afford to run
3615 	 * out of space like for example punch hole, or converting
3616 	 * unwritten extents in delalloc path. In most cases such
3617 	 * allocation would require 1, or 2 blocks, higher numbers are
3618 	 * very rare.
3619 	 */
3620 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3621 			 sbi->s_cluster_bits);
3622 
3623 	do_div(resv_clusters, 50);
3624 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3625 
3626 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3627 }
3628 
3629 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3630 {
3631 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3632 	char *orig_data = kstrdup(data, GFP_KERNEL);
3633 	struct buffer_head *bh;
3634 	struct ext4_super_block *es = NULL;
3635 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3636 	ext4_fsblk_t block;
3637 	ext4_fsblk_t sb_block = get_sb_block(&data);
3638 	ext4_fsblk_t logical_sb_block;
3639 	unsigned long offset = 0;
3640 	unsigned long journal_devnum = 0;
3641 	unsigned long def_mount_opts;
3642 	struct inode *root;
3643 	const char *descr;
3644 	int ret = -ENOMEM;
3645 	int blocksize, clustersize;
3646 	unsigned int db_count;
3647 	unsigned int i;
3648 	int needs_recovery, has_huge_files, has_bigalloc;
3649 	__u64 blocks_count;
3650 	int err = 0;
3651 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3652 	ext4_group_t first_not_zeroed;
3653 
3654 	if ((data && !orig_data) || !sbi)
3655 		goto out_free_base;
3656 
3657 	sbi->s_daxdev = dax_dev;
3658 	sbi->s_blockgroup_lock =
3659 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3660 	if (!sbi->s_blockgroup_lock)
3661 		goto out_free_base;
3662 
3663 	sb->s_fs_info = sbi;
3664 	sbi->s_sb = sb;
3665 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3666 	sbi->s_sb_block = sb_block;
3667 	if (sb->s_bdev->bd_part)
3668 		sbi->s_sectors_written_start =
3669 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3670 
3671 	/* Cleanup superblock name */
3672 	strreplace(sb->s_id, '/', '!');
3673 
3674 	/* -EINVAL is default */
3675 	ret = -EINVAL;
3676 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3677 	if (!blocksize) {
3678 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3679 		goto out_fail;
3680 	}
3681 
3682 	/*
3683 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3684 	 * block sizes.  We need to calculate the offset from buffer start.
3685 	 */
3686 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3687 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3688 		offset = do_div(logical_sb_block, blocksize);
3689 	} else {
3690 		logical_sb_block = sb_block;
3691 	}
3692 
3693 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3694 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3695 		goto out_fail;
3696 	}
3697 	/*
3698 	 * Note: s_es must be initialized as soon as possible because
3699 	 *       some ext4 macro-instructions depend on its value
3700 	 */
3701 	es = (struct ext4_super_block *) (bh->b_data + offset);
3702 	sbi->s_es = es;
3703 	sb->s_magic = le16_to_cpu(es->s_magic);
3704 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3705 		goto cantfind_ext4;
3706 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3707 
3708 	/* Warn if metadata_csum and gdt_csum are both set. */
3709 	if (ext4_has_feature_metadata_csum(sb) &&
3710 	    ext4_has_feature_gdt_csum(sb))
3711 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3712 			     "redundant flags; please run fsck.");
3713 
3714 	/* Check for a known checksum algorithm */
3715 	if (!ext4_verify_csum_type(sb, es)) {
3716 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3717 			 "unknown checksum algorithm.");
3718 		silent = 1;
3719 		goto cantfind_ext4;
3720 	}
3721 
3722 	/* Load the checksum driver */
3723 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3724 	if (IS_ERR(sbi->s_chksum_driver)) {
3725 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3726 		ret = PTR_ERR(sbi->s_chksum_driver);
3727 		sbi->s_chksum_driver = NULL;
3728 		goto failed_mount;
3729 	}
3730 
3731 	/* Check superblock checksum */
3732 	if (!ext4_superblock_csum_verify(sb, es)) {
3733 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3734 			 "invalid superblock checksum.  Run e2fsck?");
3735 		silent = 1;
3736 		ret = -EFSBADCRC;
3737 		goto cantfind_ext4;
3738 	}
3739 
3740 	/* Precompute checksum seed for all metadata */
3741 	if (ext4_has_feature_csum_seed(sb))
3742 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3743 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3744 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3745 					       sizeof(es->s_uuid));
3746 
3747 	/* Set defaults before we parse the mount options */
3748 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3749 	set_opt(sb, INIT_INODE_TABLE);
3750 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3751 		set_opt(sb, DEBUG);
3752 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3753 		set_opt(sb, GRPID);
3754 	if (def_mount_opts & EXT4_DEFM_UID16)
3755 		set_opt(sb, NO_UID32);
3756 	/* xattr user namespace & acls are now defaulted on */
3757 	set_opt(sb, XATTR_USER);
3758 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3759 	set_opt(sb, POSIX_ACL);
3760 #endif
3761 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3762 	if (ext4_has_metadata_csum(sb))
3763 		set_opt(sb, JOURNAL_CHECKSUM);
3764 
3765 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3766 		set_opt(sb, JOURNAL_DATA);
3767 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3768 		set_opt(sb, ORDERED_DATA);
3769 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3770 		set_opt(sb, WRITEBACK_DATA);
3771 
3772 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3773 		set_opt(sb, ERRORS_PANIC);
3774 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3775 		set_opt(sb, ERRORS_CONT);
3776 	else
3777 		set_opt(sb, ERRORS_RO);
3778 	/* block_validity enabled by default; disable with noblock_validity */
3779 	set_opt(sb, BLOCK_VALIDITY);
3780 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3781 		set_opt(sb, DISCARD);
3782 
3783 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3784 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3785 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3786 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3787 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3788 
3789 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3790 		set_opt(sb, BARRIER);
3791 
3792 	/*
3793 	 * enable delayed allocation by default
3794 	 * Use -o nodelalloc to turn it off
3795 	 */
3796 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3797 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3798 		set_opt(sb, DELALLOC);
3799 
3800 	/*
3801 	 * set default s_li_wait_mult for lazyinit, for the case there is
3802 	 * no mount option specified.
3803 	 */
3804 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3805 
3806 	if (sbi->s_es->s_mount_opts[0]) {
3807 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3808 					      sizeof(sbi->s_es->s_mount_opts),
3809 					      GFP_KERNEL);
3810 		if (!s_mount_opts)
3811 			goto failed_mount;
3812 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3813 				   &journal_ioprio, 0)) {
3814 			ext4_msg(sb, KERN_WARNING,
3815 				 "failed to parse options in superblock: %s",
3816 				 s_mount_opts);
3817 		}
3818 		kfree(s_mount_opts);
3819 	}
3820 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3821 	if (!parse_options((char *) data, sb, &journal_devnum,
3822 			   &journal_ioprio, 0))
3823 		goto failed_mount;
3824 
3825 #ifdef CONFIG_UNICODE
3826 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3827 		const struct ext4_sb_encodings *encoding_info;
3828 		struct unicode_map *encoding;
3829 		__u16 encoding_flags;
3830 
3831 		if (ext4_has_feature_encrypt(sb)) {
3832 			ext4_msg(sb, KERN_ERR,
3833 				 "Can't mount with encoding and encryption");
3834 			goto failed_mount;
3835 		}
3836 
3837 		if (ext4_sb_read_encoding(es, &encoding_info,
3838 					  &encoding_flags)) {
3839 			ext4_msg(sb, KERN_ERR,
3840 				 "Encoding requested by superblock is unknown");
3841 			goto failed_mount;
3842 		}
3843 
3844 		encoding = utf8_load(encoding_info->version);
3845 		if (IS_ERR(encoding)) {
3846 			ext4_msg(sb, KERN_ERR,
3847 				 "can't mount with superblock charset: %s-%s "
3848 				 "not supported by the kernel. flags: 0x%x.",
3849 				 encoding_info->name, encoding_info->version,
3850 				 encoding_flags);
3851 			goto failed_mount;
3852 		}
3853 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3854 			 "%s-%s with flags 0x%hx", encoding_info->name,
3855 			 encoding_info->version?:"\b", encoding_flags);
3856 
3857 		sbi->s_encoding = encoding;
3858 		sbi->s_encoding_flags = encoding_flags;
3859 	}
3860 #endif
3861 
3862 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3863 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3864 			    "with data=journal disables delayed "
3865 			    "allocation and O_DIRECT support!\n");
3866 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3867 			ext4_msg(sb, KERN_ERR, "can't mount with "
3868 				 "both data=journal and delalloc");
3869 			goto failed_mount;
3870 		}
3871 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3872 			ext4_msg(sb, KERN_ERR, "can't mount with "
3873 				 "both data=journal and dioread_nolock");
3874 			goto failed_mount;
3875 		}
3876 		if (test_opt(sb, DAX)) {
3877 			ext4_msg(sb, KERN_ERR, "can't mount with "
3878 				 "both data=journal and dax");
3879 			goto failed_mount;
3880 		}
3881 		if (ext4_has_feature_encrypt(sb)) {
3882 			ext4_msg(sb, KERN_WARNING,
3883 				 "encrypted files will use data=ordered "
3884 				 "instead of data journaling mode");
3885 		}
3886 		if (test_opt(sb, DELALLOC))
3887 			clear_opt(sb, DELALLOC);
3888 	} else {
3889 		sb->s_iflags |= SB_I_CGROUPWB;
3890 	}
3891 
3892 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3893 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3894 
3895 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3896 	    (ext4_has_compat_features(sb) ||
3897 	     ext4_has_ro_compat_features(sb) ||
3898 	     ext4_has_incompat_features(sb)))
3899 		ext4_msg(sb, KERN_WARNING,
3900 		       "feature flags set on rev 0 fs, "
3901 		       "running e2fsck is recommended");
3902 
3903 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3904 		set_opt2(sb, HURD_COMPAT);
3905 		if (ext4_has_feature_64bit(sb)) {
3906 			ext4_msg(sb, KERN_ERR,
3907 				 "The Hurd can't support 64-bit file systems");
3908 			goto failed_mount;
3909 		}
3910 
3911 		/*
3912 		 * ea_inode feature uses l_i_version field which is not
3913 		 * available in HURD_COMPAT mode.
3914 		 */
3915 		if (ext4_has_feature_ea_inode(sb)) {
3916 			ext4_msg(sb, KERN_ERR,
3917 				 "ea_inode feature is not supported for Hurd");
3918 			goto failed_mount;
3919 		}
3920 	}
3921 
3922 	if (IS_EXT2_SB(sb)) {
3923 		if (ext2_feature_set_ok(sb))
3924 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3925 				 "using the ext4 subsystem");
3926 		else {
3927 			/*
3928 			 * If we're probing be silent, if this looks like
3929 			 * it's actually an ext[34] filesystem.
3930 			 */
3931 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3932 				goto failed_mount;
3933 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3934 				 "to feature incompatibilities");
3935 			goto failed_mount;
3936 		}
3937 	}
3938 
3939 	if (IS_EXT3_SB(sb)) {
3940 		if (ext3_feature_set_ok(sb))
3941 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3942 				 "using the ext4 subsystem");
3943 		else {
3944 			/*
3945 			 * If we're probing be silent, if this looks like
3946 			 * it's actually an ext4 filesystem.
3947 			 */
3948 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3949 				goto failed_mount;
3950 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3951 				 "to feature incompatibilities");
3952 			goto failed_mount;
3953 		}
3954 	}
3955 
3956 	/*
3957 	 * Check feature flags regardless of the revision level, since we
3958 	 * previously didn't change the revision level when setting the flags,
3959 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3960 	 */
3961 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3962 		goto failed_mount;
3963 
3964 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3965 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3966 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3967 		ext4_msg(sb, KERN_ERR,
3968 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3969 			 blocksize, le32_to_cpu(es->s_log_block_size));
3970 		goto failed_mount;
3971 	}
3972 	if (le32_to_cpu(es->s_log_block_size) >
3973 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3974 		ext4_msg(sb, KERN_ERR,
3975 			 "Invalid log block size: %u",
3976 			 le32_to_cpu(es->s_log_block_size));
3977 		goto failed_mount;
3978 	}
3979 	if (le32_to_cpu(es->s_log_cluster_size) >
3980 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3981 		ext4_msg(sb, KERN_ERR,
3982 			 "Invalid log cluster size: %u",
3983 			 le32_to_cpu(es->s_log_cluster_size));
3984 		goto failed_mount;
3985 	}
3986 
3987 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3988 		ext4_msg(sb, KERN_ERR,
3989 			 "Number of reserved GDT blocks insanely large: %d",
3990 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3991 		goto failed_mount;
3992 	}
3993 
3994 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3995 		if (ext4_has_feature_inline_data(sb)) {
3996 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3997 					" that may contain inline data");
3998 			goto failed_mount;
3999 		}
4000 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
4001 			ext4_msg(sb, KERN_ERR,
4002 				"DAX unsupported by block device.");
4003 			goto failed_mount;
4004 		}
4005 	}
4006 
4007 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4008 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4009 			 es->s_encryption_level);
4010 		goto failed_mount;
4011 	}
4012 
4013 	if (sb->s_blocksize != blocksize) {
4014 		/* Validate the filesystem blocksize */
4015 		if (!sb_set_blocksize(sb, blocksize)) {
4016 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4017 					blocksize);
4018 			goto failed_mount;
4019 		}
4020 
4021 		brelse(bh);
4022 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4023 		offset = do_div(logical_sb_block, blocksize);
4024 		bh = sb_bread_unmovable(sb, logical_sb_block);
4025 		if (!bh) {
4026 			ext4_msg(sb, KERN_ERR,
4027 			       "Can't read superblock on 2nd try");
4028 			goto failed_mount;
4029 		}
4030 		es = (struct ext4_super_block *)(bh->b_data + offset);
4031 		sbi->s_es = es;
4032 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4033 			ext4_msg(sb, KERN_ERR,
4034 			       "Magic mismatch, very weird!");
4035 			goto failed_mount;
4036 		}
4037 	}
4038 
4039 	has_huge_files = ext4_has_feature_huge_file(sb);
4040 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4041 						      has_huge_files);
4042 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4043 
4044 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4045 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4046 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4047 	} else {
4048 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4049 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4050 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4051 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4052 				 sbi->s_first_ino);
4053 			goto failed_mount;
4054 		}
4055 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4056 		    (!is_power_of_2(sbi->s_inode_size)) ||
4057 		    (sbi->s_inode_size > blocksize)) {
4058 			ext4_msg(sb, KERN_ERR,
4059 			       "unsupported inode size: %d",
4060 			       sbi->s_inode_size);
4061 			goto failed_mount;
4062 		}
4063 		/*
4064 		 * i_atime_extra is the last extra field available for [acm]times in
4065 		 * struct ext4_inode. Checking for that field should suffice to ensure
4066 		 * we have extra space for all three.
4067 		 */
4068 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4069 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4070 			sb->s_time_gran = 1;
4071 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4072 		} else {
4073 			sb->s_time_gran = NSEC_PER_SEC;
4074 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4075 		}
4076 
4077 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4078 	}
4079 
4080 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4081 	if (ext4_has_feature_64bit(sb)) {
4082 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4083 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4084 		    !is_power_of_2(sbi->s_desc_size)) {
4085 			ext4_msg(sb, KERN_ERR,
4086 			       "unsupported descriptor size %lu",
4087 			       sbi->s_desc_size);
4088 			goto failed_mount;
4089 		}
4090 	} else
4091 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4092 
4093 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4094 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4095 
4096 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4097 	if (sbi->s_inodes_per_block == 0)
4098 		goto cantfind_ext4;
4099 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4100 	    sbi->s_inodes_per_group > blocksize * 8) {
4101 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4102 			 sbi->s_blocks_per_group);
4103 		goto failed_mount;
4104 	}
4105 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4106 					sbi->s_inodes_per_block;
4107 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4108 	sbi->s_sbh = bh;
4109 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4110 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4111 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4112 
4113 	for (i = 0; i < 4; i++)
4114 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4115 	sbi->s_def_hash_version = es->s_def_hash_version;
4116 	if (ext4_has_feature_dir_index(sb)) {
4117 		i = le32_to_cpu(es->s_flags);
4118 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4119 			sbi->s_hash_unsigned = 3;
4120 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4121 #ifdef __CHAR_UNSIGNED__
4122 			if (!sb_rdonly(sb))
4123 				es->s_flags |=
4124 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4125 			sbi->s_hash_unsigned = 3;
4126 #else
4127 			if (!sb_rdonly(sb))
4128 				es->s_flags |=
4129 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4130 #endif
4131 		}
4132 	}
4133 
4134 	/* Handle clustersize */
4135 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4136 	has_bigalloc = ext4_has_feature_bigalloc(sb);
4137 	if (has_bigalloc) {
4138 		if (clustersize < blocksize) {
4139 			ext4_msg(sb, KERN_ERR,
4140 				 "cluster size (%d) smaller than "
4141 				 "block size (%d)", clustersize, blocksize);
4142 			goto failed_mount;
4143 		}
4144 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4145 			le32_to_cpu(es->s_log_block_size);
4146 		sbi->s_clusters_per_group =
4147 			le32_to_cpu(es->s_clusters_per_group);
4148 		if (sbi->s_clusters_per_group > blocksize * 8) {
4149 			ext4_msg(sb, KERN_ERR,
4150 				 "#clusters per group too big: %lu",
4151 				 sbi->s_clusters_per_group);
4152 			goto failed_mount;
4153 		}
4154 		if (sbi->s_blocks_per_group !=
4155 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4156 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4157 				 "clusters per group (%lu) inconsistent",
4158 				 sbi->s_blocks_per_group,
4159 				 sbi->s_clusters_per_group);
4160 			goto failed_mount;
4161 		}
4162 	} else {
4163 		if (clustersize != blocksize) {
4164 			ext4_msg(sb, KERN_ERR,
4165 				 "fragment/cluster size (%d) != "
4166 				 "block size (%d)", clustersize, blocksize);
4167 			goto failed_mount;
4168 		}
4169 		if (sbi->s_blocks_per_group > blocksize * 8) {
4170 			ext4_msg(sb, KERN_ERR,
4171 				 "#blocks per group too big: %lu",
4172 				 sbi->s_blocks_per_group);
4173 			goto failed_mount;
4174 		}
4175 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4176 		sbi->s_cluster_bits = 0;
4177 	}
4178 	sbi->s_cluster_ratio = clustersize / blocksize;
4179 
4180 	/* Do we have standard group size of clustersize * 8 blocks ? */
4181 	if (sbi->s_blocks_per_group == clustersize << 3)
4182 		set_opt2(sb, STD_GROUP_SIZE);
4183 
4184 	/*
4185 	 * Test whether we have more sectors than will fit in sector_t,
4186 	 * and whether the max offset is addressable by the page cache.
4187 	 */
4188 	err = generic_check_addressable(sb->s_blocksize_bits,
4189 					ext4_blocks_count(es));
4190 	if (err) {
4191 		ext4_msg(sb, KERN_ERR, "filesystem"
4192 			 " too large to mount safely on this system");
4193 		goto failed_mount;
4194 	}
4195 
4196 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4197 		goto cantfind_ext4;
4198 
4199 	/* check blocks count against device size */
4200 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4201 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4202 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4203 		       "exceeds size of device (%llu blocks)",
4204 		       ext4_blocks_count(es), blocks_count);
4205 		goto failed_mount;
4206 	}
4207 
4208 	/*
4209 	 * It makes no sense for the first data block to be beyond the end
4210 	 * of the filesystem.
4211 	 */
4212 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4213 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4214 			 "block %u is beyond end of filesystem (%llu)",
4215 			 le32_to_cpu(es->s_first_data_block),
4216 			 ext4_blocks_count(es));
4217 		goto failed_mount;
4218 	}
4219 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4220 	    (sbi->s_cluster_ratio == 1)) {
4221 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4222 			 "block is 0 with a 1k block and cluster size");
4223 		goto failed_mount;
4224 	}
4225 
4226 	blocks_count = (ext4_blocks_count(es) -
4227 			le32_to_cpu(es->s_first_data_block) +
4228 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4229 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4230 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4231 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4232 		       "(block count %llu, first data block %u, "
4233 		       "blocks per group %lu)", sbi->s_groups_count,
4234 		       ext4_blocks_count(es),
4235 		       le32_to_cpu(es->s_first_data_block),
4236 		       EXT4_BLOCKS_PER_GROUP(sb));
4237 		goto failed_mount;
4238 	}
4239 	sbi->s_groups_count = blocks_count;
4240 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4241 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4242 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4243 	    le32_to_cpu(es->s_inodes_count)) {
4244 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4245 			 le32_to_cpu(es->s_inodes_count),
4246 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4247 		ret = -EINVAL;
4248 		goto failed_mount;
4249 	}
4250 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4251 		   EXT4_DESC_PER_BLOCK(sb);
4252 	if (ext4_has_feature_meta_bg(sb)) {
4253 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4254 			ext4_msg(sb, KERN_WARNING,
4255 				 "first meta block group too large: %u "
4256 				 "(group descriptor block count %u)",
4257 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4258 			goto failed_mount;
4259 		}
4260 	}
4261 	sbi->s_group_desc = kvmalloc_array(db_count,
4262 					   sizeof(struct buffer_head *),
4263 					   GFP_KERNEL);
4264 	if (sbi->s_group_desc == NULL) {
4265 		ext4_msg(sb, KERN_ERR, "not enough memory");
4266 		ret = -ENOMEM;
4267 		goto failed_mount;
4268 	}
4269 
4270 	bgl_lock_init(sbi->s_blockgroup_lock);
4271 
4272 	/* Pre-read the descriptors into the buffer cache */
4273 	for (i = 0; i < db_count; i++) {
4274 		block = descriptor_loc(sb, logical_sb_block, i);
4275 		sb_breadahead(sb, block);
4276 	}
4277 
4278 	for (i = 0; i < db_count; i++) {
4279 		block = descriptor_loc(sb, logical_sb_block, i);
4280 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4281 		if (!sbi->s_group_desc[i]) {
4282 			ext4_msg(sb, KERN_ERR,
4283 			       "can't read group descriptor %d", i);
4284 			db_count = i;
4285 			goto failed_mount2;
4286 		}
4287 	}
4288 	sbi->s_gdb_count = db_count;
4289 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4290 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4291 		ret = -EFSCORRUPTED;
4292 		goto failed_mount2;
4293 	}
4294 
4295 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4296 
4297 	/* Register extent status tree shrinker */
4298 	if (ext4_es_register_shrinker(sbi))
4299 		goto failed_mount3;
4300 
4301 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4302 	sbi->s_extent_max_zeroout_kb = 32;
4303 
4304 	/*
4305 	 * set up enough so that it can read an inode
4306 	 */
4307 	sb->s_op = &ext4_sops;
4308 	sb->s_export_op = &ext4_export_ops;
4309 	sb->s_xattr = ext4_xattr_handlers;
4310 #ifdef CONFIG_FS_ENCRYPTION
4311 	sb->s_cop = &ext4_cryptops;
4312 #endif
4313 #ifdef CONFIG_FS_VERITY
4314 	sb->s_vop = &ext4_verityops;
4315 #endif
4316 #ifdef CONFIG_QUOTA
4317 	sb->dq_op = &ext4_quota_operations;
4318 	if (ext4_has_feature_quota(sb))
4319 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4320 	else
4321 		sb->s_qcop = &ext4_qctl_operations;
4322 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4323 #endif
4324 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4325 
4326 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4327 	mutex_init(&sbi->s_orphan_lock);
4328 
4329 	sb->s_root = NULL;
4330 
4331 	needs_recovery = (es->s_last_orphan != 0 ||
4332 			  ext4_has_feature_journal_needs_recovery(sb));
4333 
4334 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4335 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4336 			goto failed_mount3a;
4337 
4338 	/*
4339 	 * The first inode we look at is the journal inode.  Don't try
4340 	 * root first: it may be modified in the journal!
4341 	 */
4342 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4343 		err = ext4_load_journal(sb, es, journal_devnum);
4344 		if (err)
4345 			goto failed_mount3a;
4346 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4347 		   ext4_has_feature_journal_needs_recovery(sb)) {
4348 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4349 		       "suppressed and not mounted read-only");
4350 		goto failed_mount_wq;
4351 	} else {
4352 		/* Nojournal mode, all journal mount options are illegal */
4353 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4354 			ext4_msg(sb, KERN_ERR, "can't mount with "
4355 				 "journal_checksum, fs mounted w/o journal");
4356 			goto failed_mount_wq;
4357 		}
4358 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4359 			ext4_msg(sb, KERN_ERR, "can't mount with "
4360 				 "journal_async_commit, fs mounted w/o journal");
4361 			goto failed_mount_wq;
4362 		}
4363 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4364 			ext4_msg(sb, KERN_ERR, "can't mount with "
4365 				 "commit=%lu, fs mounted w/o journal",
4366 				 sbi->s_commit_interval / HZ);
4367 			goto failed_mount_wq;
4368 		}
4369 		if (EXT4_MOUNT_DATA_FLAGS &
4370 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4371 			ext4_msg(sb, KERN_ERR, "can't mount with "
4372 				 "data=, fs mounted w/o journal");
4373 			goto failed_mount_wq;
4374 		}
4375 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4376 		clear_opt(sb, JOURNAL_CHECKSUM);
4377 		clear_opt(sb, DATA_FLAGS);
4378 		sbi->s_journal = NULL;
4379 		needs_recovery = 0;
4380 		goto no_journal;
4381 	}
4382 
4383 	if (ext4_has_feature_64bit(sb) &&
4384 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4385 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4386 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4387 		goto failed_mount_wq;
4388 	}
4389 
4390 	if (!set_journal_csum_feature_set(sb)) {
4391 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4392 			 "feature set");
4393 		goto failed_mount_wq;
4394 	}
4395 
4396 	/* We have now updated the journal if required, so we can
4397 	 * validate the data journaling mode. */
4398 	switch (test_opt(sb, DATA_FLAGS)) {
4399 	case 0:
4400 		/* No mode set, assume a default based on the journal
4401 		 * capabilities: ORDERED_DATA if the journal can
4402 		 * cope, else JOURNAL_DATA
4403 		 */
4404 		if (jbd2_journal_check_available_features
4405 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4406 			set_opt(sb, ORDERED_DATA);
4407 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4408 		} else {
4409 			set_opt(sb, JOURNAL_DATA);
4410 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4411 		}
4412 		break;
4413 
4414 	case EXT4_MOUNT_ORDERED_DATA:
4415 	case EXT4_MOUNT_WRITEBACK_DATA:
4416 		if (!jbd2_journal_check_available_features
4417 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4418 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4419 			       "requested data journaling mode");
4420 			goto failed_mount_wq;
4421 		}
4422 	default:
4423 		break;
4424 	}
4425 
4426 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4427 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4428 		ext4_msg(sb, KERN_ERR, "can't mount with "
4429 			"journal_async_commit in data=ordered mode");
4430 		goto failed_mount_wq;
4431 	}
4432 
4433 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4434 
4435 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4436 
4437 no_journal:
4438 	if (!test_opt(sb, NO_MBCACHE)) {
4439 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4440 		if (!sbi->s_ea_block_cache) {
4441 			ext4_msg(sb, KERN_ERR,
4442 				 "Failed to create ea_block_cache");
4443 			goto failed_mount_wq;
4444 		}
4445 
4446 		if (ext4_has_feature_ea_inode(sb)) {
4447 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4448 			if (!sbi->s_ea_inode_cache) {
4449 				ext4_msg(sb, KERN_ERR,
4450 					 "Failed to create ea_inode_cache");
4451 				goto failed_mount_wq;
4452 			}
4453 		}
4454 	}
4455 
4456 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4457 	    (blocksize != PAGE_SIZE)) {
4458 		ext4_msg(sb, KERN_ERR,
4459 			 "Unsupported blocksize for fs encryption");
4460 		goto failed_mount_wq;
4461 	}
4462 
4463 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4464 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4465 		goto failed_mount_wq;
4466 	}
4467 
4468 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4469 	    !ext4_has_feature_encrypt(sb)) {
4470 		ext4_set_feature_encrypt(sb);
4471 		ext4_commit_super(sb, 1);
4472 	}
4473 
4474 	/*
4475 	 * Get the # of file system overhead blocks from the
4476 	 * superblock if present.
4477 	 */
4478 	if (es->s_overhead_clusters)
4479 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4480 	else {
4481 		err = ext4_calculate_overhead(sb);
4482 		if (err)
4483 			goto failed_mount_wq;
4484 	}
4485 
4486 	/*
4487 	 * The maximum number of concurrent works can be high and
4488 	 * concurrency isn't really necessary.  Limit it to 1.
4489 	 */
4490 	EXT4_SB(sb)->rsv_conversion_wq =
4491 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4492 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4493 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4494 		ret = -ENOMEM;
4495 		goto failed_mount4;
4496 	}
4497 
4498 	/*
4499 	 * The jbd2_journal_load will have done any necessary log recovery,
4500 	 * so we can safely mount the rest of the filesystem now.
4501 	 */
4502 
4503 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4504 	if (IS_ERR(root)) {
4505 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4506 		ret = PTR_ERR(root);
4507 		root = NULL;
4508 		goto failed_mount4;
4509 	}
4510 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4511 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4512 		iput(root);
4513 		goto failed_mount4;
4514 	}
4515 
4516 #ifdef CONFIG_UNICODE
4517 	if (sbi->s_encoding)
4518 		sb->s_d_op = &ext4_dentry_ops;
4519 #endif
4520 
4521 	sb->s_root = d_make_root(root);
4522 	if (!sb->s_root) {
4523 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4524 		ret = -ENOMEM;
4525 		goto failed_mount4;
4526 	}
4527 
4528 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4529 	if (ret == -EROFS) {
4530 		sb->s_flags |= SB_RDONLY;
4531 		ret = 0;
4532 	} else if (ret)
4533 		goto failed_mount4a;
4534 
4535 	ext4_clamp_want_extra_isize(sb);
4536 
4537 	ext4_set_resv_clusters(sb);
4538 
4539 	err = ext4_setup_system_zone(sb);
4540 	if (err) {
4541 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4542 			 "zone (%d)", err);
4543 		goto failed_mount4a;
4544 	}
4545 
4546 	ext4_ext_init(sb);
4547 	err = ext4_mb_init(sb);
4548 	if (err) {
4549 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4550 			 err);
4551 		goto failed_mount5;
4552 	}
4553 
4554 	block = ext4_count_free_clusters(sb);
4555 	ext4_free_blocks_count_set(sbi->s_es,
4556 				   EXT4_C2B(sbi, block));
4557 	ext4_superblock_csum_set(sb);
4558 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4559 				  GFP_KERNEL);
4560 	if (!err) {
4561 		unsigned long freei = ext4_count_free_inodes(sb);
4562 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4563 		ext4_superblock_csum_set(sb);
4564 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4565 					  GFP_KERNEL);
4566 	}
4567 	if (!err)
4568 		err = percpu_counter_init(&sbi->s_dirs_counter,
4569 					  ext4_count_dirs(sb), GFP_KERNEL);
4570 	if (!err)
4571 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4572 					  GFP_KERNEL);
4573 	if (!err)
4574 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4575 
4576 	if (err) {
4577 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4578 		goto failed_mount6;
4579 	}
4580 
4581 	if (ext4_has_feature_flex_bg(sb))
4582 		if (!ext4_fill_flex_info(sb)) {
4583 			ext4_msg(sb, KERN_ERR,
4584 			       "unable to initialize "
4585 			       "flex_bg meta info!");
4586 			goto failed_mount6;
4587 		}
4588 
4589 	err = ext4_register_li_request(sb, first_not_zeroed);
4590 	if (err)
4591 		goto failed_mount6;
4592 
4593 	err = ext4_register_sysfs(sb);
4594 	if (err)
4595 		goto failed_mount7;
4596 
4597 #ifdef CONFIG_QUOTA
4598 	/* Enable quota usage during mount. */
4599 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4600 		err = ext4_enable_quotas(sb);
4601 		if (err)
4602 			goto failed_mount8;
4603 	}
4604 #endif  /* CONFIG_QUOTA */
4605 
4606 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4607 	ext4_orphan_cleanup(sb, es);
4608 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4609 	if (needs_recovery) {
4610 		ext4_msg(sb, KERN_INFO, "recovery complete");
4611 		ext4_mark_recovery_complete(sb, es);
4612 	}
4613 	if (EXT4_SB(sb)->s_journal) {
4614 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4615 			descr = " journalled data mode";
4616 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4617 			descr = " ordered data mode";
4618 		else
4619 			descr = " writeback data mode";
4620 	} else
4621 		descr = "out journal";
4622 
4623 	if (test_opt(sb, DISCARD)) {
4624 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4625 		if (!blk_queue_discard(q))
4626 			ext4_msg(sb, KERN_WARNING,
4627 				 "mounting with \"discard\" option, but "
4628 				 "the device does not support discard");
4629 	}
4630 
4631 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4632 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4633 			 "Opts: %.*s%s%s", descr,
4634 			 (int) sizeof(sbi->s_es->s_mount_opts),
4635 			 sbi->s_es->s_mount_opts,
4636 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4637 
4638 	if (es->s_error_count)
4639 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4640 
4641 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4642 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4643 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4644 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4645 
4646 	kfree(orig_data);
4647 	return 0;
4648 
4649 cantfind_ext4:
4650 	if (!silent)
4651 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4652 	goto failed_mount;
4653 
4654 #ifdef CONFIG_QUOTA
4655 failed_mount8:
4656 	ext4_unregister_sysfs(sb);
4657 #endif
4658 failed_mount7:
4659 	ext4_unregister_li_request(sb);
4660 failed_mount6:
4661 	ext4_mb_release(sb);
4662 	if (sbi->s_flex_groups)
4663 		kvfree(sbi->s_flex_groups);
4664 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4665 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4666 	percpu_counter_destroy(&sbi->s_dirs_counter);
4667 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4668 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4669 failed_mount5:
4670 	ext4_ext_release(sb);
4671 	ext4_release_system_zone(sb);
4672 failed_mount4a:
4673 	dput(sb->s_root);
4674 	sb->s_root = NULL;
4675 failed_mount4:
4676 	ext4_msg(sb, KERN_ERR, "mount failed");
4677 	if (EXT4_SB(sb)->rsv_conversion_wq)
4678 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4679 failed_mount_wq:
4680 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4681 	sbi->s_ea_inode_cache = NULL;
4682 
4683 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4684 	sbi->s_ea_block_cache = NULL;
4685 
4686 	if (sbi->s_journal) {
4687 		jbd2_journal_destroy(sbi->s_journal);
4688 		sbi->s_journal = NULL;
4689 	}
4690 failed_mount3a:
4691 	ext4_es_unregister_shrinker(sbi);
4692 failed_mount3:
4693 	del_timer_sync(&sbi->s_err_report);
4694 	if (sbi->s_mmp_tsk)
4695 		kthread_stop(sbi->s_mmp_tsk);
4696 failed_mount2:
4697 	for (i = 0; i < db_count; i++)
4698 		brelse(sbi->s_group_desc[i]);
4699 	kvfree(sbi->s_group_desc);
4700 failed_mount:
4701 	if (sbi->s_chksum_driver)
4702 		crypto_free_shash(sbi->s_chksum_driver);
4703 
4704 #ifdef CONFIG_UNICODE
4705 	utf8_unload(sbi->s_encoding);
4706 #endif
4707 
4708 #ifdef CONFIG_QUOTA
4709 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4710 		kfree(get_qf_name(sb, sbi, i));
4711 #endif
4712 	ext4_blkdev_remove(sbi);
4713 	brelse(bh);
4714 out_fail:
4715 	sb->s_fs_info = NULL;
4716 	kfree(sbi->s_blockgroup_lock);
4717 out_free_base:
4718 	kfree(sbi);
4719 	kfree(orig_data);
4720 	fs_put_dax(dax_dev);
4721 	return err ? err : ret;
4722 }
4723 
4724 /*
4725  * Setup any per-fs journal parameters now.  We'll do this both on
4726  * initial mount, once the journal has been initialised but before we've
4727  * done any recovery; and again on any subsequent remount.
4728  */
4729 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4730 {
4731 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4732 
4733 	journal->j_commit_interval = sbi->s_commit_interval;
4734 	journal->j_min_batch_time = sbi->s_min_batch_time;
4735 	journal->j_max_batch_time = sbi->s_max_batch_time;
4736 
4737 	write_lock(&journal->j_state_lock);
4738 	if (test_opt(sb, BARRIER))
4739 		journal->j_flags |= JBD2_BARRIER;
4740 	else
4741 		journal->j_flags &= ~JBD2_BARRIER;
4742 	if (test_opt(sb, DATA_ERR_ABORT))
4743 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4744 	else
4745 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4746 	write_unlock(&journal->j_state_lock);
4747 }
4748 
4749 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4750 					     unsigned int journal_inum)
4751 {
4752 	struct inode *journal_inode;
4753 
4754 	/*
4755 	 * Test for the existence of a valid inode on disk.  Bad things
4756 	 * happen if we iget() an unused inode, as the subsequent iput()
4757 	 * will try to delete it.
4758 	 */
4759 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4760 	if (IS_ERR(journal_inode)) {
4761 		ext4_msg(sb, KERN_ERR, "no journal found");
4762 		return NULL;
4763 	}
4764 	if (!journal_inode->i_nlink) {
4765 		make_bad_inode(journal_inode);
4766 		iput(journal_inode);
4767 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4768 		return NULL;
4769 	}
4770 
4771 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4772 		  journal_inode, journal_inode->i_size);
4773 	if (!S_ISREG(journal_inode->i_mode)) {
4774 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4775 		iput(journal_inode);
4776 		return NULL;
4777 	}
4778 	return journal_inode;
4779 }
4780 
4781 static journal_t *ext4_get_journal(struct super_block *sb,
4782 				   unsigned int journal_inum)
4783 {
4784 	struct inode *journal_inode;
4785 	journal_t *journal;
4786 
4787 	BUG_ON(!ext4_has_feature_journal(sb));
4788 
4789 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4790 	if (!journal_inode)
4791 		return NULL;
4792 
4793 	journal = jbd2_journal_init_inode(journal_inode);
4794 	if (!journal) {
4795 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4796 		iput(journal_inode);
4797 		return NULL;
4798 	}
4799 	journal->j_private = sb;
4800 	ext4_init_journal_params(sb, journal);
4801 	return journal;
4802 }
4803 
4804 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4805 				       dev_t j_dev)
4806 {
4807 	struct buffer_head *bh;
4808 	journal_t *journal;
4809 	ext4_fsblk_t start;
4810 	ext4_fsblk_t len;
4811 	int hblock, blocksize;
4812 	ext4_fsblk_t sb_block;
4813 	unsigned long offset;
4814 	struct ext4_super_block *es;
4815 	struct block_device *bdev;
4816 
4817 	BUG_ON(!ext4_has_feature_journal(sb));
4818 
4819 	bdev = ext4_blkdev_get(j_dev, sb);
4820 	if (bdev == NULL)
4821 		return NULL;
4822 
4823 	blocksize = sb->s_blocksize;
4824 	hblock = bdev_logical_block_size(bdev);
4825 	if (blocksize < hblock) {
4826 		ext4_msg(sb, KERN_ERR,
4827 			"blocksize too small for journal device");
4828 		goto out_bdev;
4829 	}
4830 
4831 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4832 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4833 	set_blocksize(bdev, blocksize);
4834 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4835 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4836 		       "external journal");
4837 		goto out_bdev;
4838 	}
4839 
4840 	es = (struct ext4_super_block *) (bh->b_data + offset);
4841 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4842 	    !(le32_to_cpu(es->s_feature_incompat) &
4843 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4844 		ext4_msg(sb, KERN_ERR, "external journal has "
4845 					"bad superblock");
4846 		brelse(bh);
4847 		goto out_bdev;
4848 	}
4849 
4850 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4851 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4852 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4853 		ext4_msg(sb, KERN_ERR, "external journal has "
4854 				       "corrupt superblock");
4855 		brelse(bh);
4856 		goto out_bdev;
4857 	}
4858 
4859 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4860 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4861 		brelse(bh);
4862 		goto out_bdev;
4863 	}
4864 
4865 	len = ext4_blocks_count(es);
4866 	start = sb_block + 1;
4867 	brelse(bh);	/* we're done with the superblock */
4868 
4869 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4870 					start, len, blocksize);
4871 	if (!journal) {
4872 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4873 		goto out_bdev;
4874 	}
4875 	journal->j_private = sb;
4876 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4877 	wait_on_buffer(journal->j_sb_buffer);
4878 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4879 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4880 		goto out_journal;
4881 	}
4882 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4883 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4884 					"user (unsupported) - %d",
4885 			be32_to_cpu(journal->j_superblock->s_nr_users));
4886 		goto out_journal;
4887 	}
4888 	EXT4_SB(sb)->journal_bdev = bdev;
4889 	ext4_init_journal_params(sb, journal);
4890 	return journal;
4891 
4892 out_journal:
4893 	jbd2_journal_destroy(journal);
4894 out_bdev:
4895 	ext4_blkdev_put(bdev);
4896 	return NULL;
4897 }
4898 
4899 static int ext4_load_journal(struct super_block *sb,
4900 			     struct ext4_super_block *es,
4901 			     unsigned long journal_devnum)
4902 {
4903 	journal_t *journal;
4904 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4905 	dev_t journal_dev;
4906 	int err = 0;
4907 	int really_read_only;
4908 
4909 	BUG_ON(!ext4_has_feature_journal(sb));
4910 
4911 	if (journal_devnum &&
4912 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4913 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4914 			"numbers have changed");
4915 		journal_dev = new_decode_dev(journal_devnum);
4916 	} else
4917 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4918 
4919 	really_read_only = bdev_read_only(sb->s_bdev);
4920 
4921 	/*
4922 	 * Are we loading a blank journal or performing recovery after a
4923 	 * crash?  For recovery, we need to check in advance whether we
4924 	 * can get read-write access to the device.
4925 	 */
4926 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4927 		if (sb_rdonly(sb)) {
4928 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4929 					"required on readonly filesystem");
4930 			if (really_read_only) {
4931 				ext4_msg(sb, KERN_ERR, "write access "
4932 					"unavailable, cannot proceed "
4933 					"(try mounting with noload)");
4934 				return -EROFS;
4935 			}
4936 			ext4_msg(sb, KERN_INFO, "write access will "
4937 			       "be enabled during recovery");
4938 		}
4939 	}
4940 
4941 	if (journal_inum && journal_dev) {
4942 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4943 		       "and inode journals!");
4944 		return -EINVAL;
4945 	}
4946 
4947 	if (journal_inum) {
4948 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4949 			return -EINVAL;
4950 	} else {
4951 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4952 			return -EINVAL;
4953 	}
4954 
4955 	if (!(journal->j_flags & JBD2_BARRIER))
4956 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4957 
4958 	if (!ext4_has_feature_journal_needs_recovery(sb))
4959 		err = jbd2_journal_wipe(journal, !really_read_only);
4960 	if (!err) {
4961 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4962 		if (save)
4963 			memcpy(save, ((char *) es) +
4964 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4965 		err = jbd2_journal_load(journal);
4966 		if (save)
4967 			memcpy(((char *) es) + EXT4_S_ERR_START,
4968 			       save, EXT4_S_ERR_LEN);
4969 		kfree(save);
4970 	}
4971 
4972 	if (err) {
4973 		ext4_msg(sb, KERN_ERR, "error loading journal");
4974 		jbd2_journal_destroy(journal);
4975 		return err;
4976 	}
4977 
4978 	EXT4_SB(sb)->s_journal = journal;
4979 	ext4_clear_journal_err(sb, es);
4980 
4981 	if (!really_read_only && journal_devnum &&
4982 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4983 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4984 
4985 		/* Make sure we flush the recovery flag to disk. */
4986 		ext4_commit_super(sb, 1);
4987 	}
4988 
4989 	return 0;
4990 }
4991 
4992 static int ext4_commit_super(struct super_block *sb, int sync)
4993 {
4994 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4995 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4996 	int error = 0;
4997 
4998 	if (!sbh || block_device_ejected(sb))
4999 		return error;
5000 
5001 	/*
5002 	 * The superblock bh should be mapped, but it might not be if the
5003 	 * device was hot-removed. Not much we can do but fail the I/O.
5004 	 */
5005 	if (!buffer_mapped(sbh))
5006 		return error;
5007 
5008 	/*
5009 	 * If the file system is mounted read-only, don't update the
5010 	 * superblock write time.  This avoids updating the superblock
5011 	 * write time when we are mounting the root file system
5012 	 * read/only but we need to replay the journal; at that point,
5013 	 * for people who are east of GMT and who make their clock
5014 	 * tick in localtime for Windows bug-for-bug compatibility,
5015 	 * the clock is set in the future, and this will cause e2fsck
5016 	 * to complain and force a full file system check.
5017 	 */
5018 	if (!(sb->s_flags & SB_RDONLY))
5019 		ext4_update_tstamp(es, s_wtime);
5020 	if (sb->s_bdev->bd_part)
5021 		es->s_kbytes_written =
5022 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5023 			    ((part_stat_read(sb->s_bdev->bd_part,
5024 					     sectors[STAT_WRITE]) -
5025 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5026 	else
5027 		es->s_kbytes_written =
5028 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5029 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5030 		ext4_free_blocks_count_set(es,
5031 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5032 				&EXT4_SB(sb)->s_freeclusters_counter)));
5033 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5034 		es->s_free_inodes_count =
5035 			cpu_to_le32(percpu_counter_sum_positive(
5036 				&EXT4_SB(sb)->s_freeinodes_counter));
5037 	BUFFER_TRACE(sbh, "marking dirty");
5038 	ext4_superblock_csum_set(sb);
5039 	if (sync)
5040 		lock_buffer(sbh);
5041 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5042 		/*
5043 		 * Oh, dear.  A previous attempt to write the
5044 		 * superblock failed.  This could happen because the
5045 		 * USB device was yanked out.  Or it could happen to
5046 		 * be a transient write error and maybe the block will
5047 		 * be remapped.  Nothing we can do but to retry the
5048 		 * write and hope for the best.
5049 		 */
5050 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5051 		       "superblock detected");
5052 		clear_buffer_write_io_error(sbh);
5053 		set_buffer_uptodate(sbh);
5054 	}
5055 	mark_buffer_dirty(sbh);
5056 	if (sync) {
5057 		unlock_buffer(sbh);
5058 		error = __sync_dirty_buffer(sbh,
5059 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5060 		if (buffer_write_io_error(sbh)) {
5061 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5062 			       "superblock");
5063 			clear_buffer_write_io_error(sbh);
5064 			set_buffer_uptodate(sbh);
5065 		}
5066 	}
5067 	return error;
5068 }
5069 
5070 /*
5071  * Have we just finished recovery?  If so, and if we are mounting (or
5072  * remounting) the filesystem readonly, then we will end up with a
5073  * consistent fs on disk.  Record that fact.
5074  */
5075 static void ext4_mark_recovery_complete(struct super_block *sb,
5076 					struct ext4_super_block *es)
5077 {
5078 	journal_t *journal = EXT4_SB(sb)->s_journal;
5079 
5080 	if (!ext4_has_feature_journal(sb)) {
5081 		BUG_ON(journal != NULL);
5082 		return;
5083 	}
5084 	jbd2_journal_lock_updates(journal);
5085 	if (jbd2_journal_flush(journal) < 0)
5086 		goto out;
5087 
5088 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5089 		ext4_clear_feature_journal_needs_recovery(sb);
5090 		ext4_commit_super(sb, 1);
5091 	}
5092 
5093 out:
5094 	jbd2_journal_unlock_updates(journal);
5095 }
5096 
5097 /*
5098  * If we are mounting (or read-write remounting) a filesystem whose journal
5099  * has recorded an error from a previous lifetime, move that error to the
5100  * main filesystem now.
5101  */
5102 static void ext4_clear_journal_err(struct super_block *sb,
5103 				   struct ext4_super_block *es)
5104 {
5105 	journal_t *journal;
5106 	int j_errno;
5107 	const char *errstr;
5108 
5109 	BUG_ON(!ext4_has_feature_journal(sb));
5110 
5111 	journal = EXT4_SB(sb)->s_journal;
5112 
5113 	/*
5114 	 * Now check for any error status which may have been recorded in the
5115 	 * journal by a prior ext4_error() or ext4_abort()
5116 	 */
5117 
5118 	j_errno = jbd2_journal_errno(journal);
5119 	if (j_errno) {
5120 		char nbuf[16];
5121 
5122 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5123 		ext4_warning(sb, "Filesystem error recorded "
5124 			     "from previous mount: %s", errstr);
5125 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5126 
5127 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5128 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5129 		ext4_commit_super(sb, 1);
5130 
5131 		jbd2_journal_clear_err(journal);
5132 		jbd2_journal_update_sb_errno(journal);
5133 	}
5134 }
5135 
5136 /*
5137  * Force the running and committing transactions to commit,
5138  * and wait on the commit.
5139  */
5140 int ext4_force_commit(struct super_block *sb)
5141 {
5142 	journal_t *journal;
5143 
5144 	if (sb_rdonly(sb))
5145 		return 0;
5146 
5147 	journal = EXT4_SB(sb)->s_journal;
5148 	return ext4_journal_force_commit(journal);
5149 }
5150 
5151 static int ext4_sync_fs(struct super_block *sb, int wait)
5152 {
5153 	int ret = 0;
5154 	tid_t target;
5155 	bool needs_barrier = false;
5156 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5157 
5158 	if (unlikely(ext4_forced_shutdown(sbi)))
5159 		return 0;
5160 
5161 	trace_ext4_sync_fs(sb, wait);
5162 	flush_workqueue(sbi->rsv_conversion_wq);
5163 	/*
5164 	 * Writeback quota in non-journalled quota case - journalled quota has
5165 	 * no dirty dquots
5166 	 */
5167 	dquot_writeback_dquots(sb, -1);
5168 	/*
5169 	 * Data writeback is possible w/o journal transaction, so barrier must
5170 	 * being sent at the end of the function. But we can skip it if
5171 	 * transaction_commit will do it for us.
5172 	 */
5173 	if (sbi->s_journal) {
5174 		target = jbd2_get_latest_transaction(sbi->s_journal);
5175 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5176 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5177 			needs_barrier = true;
5178 
5179 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5180 			if (wait)
5181 				ret = jbd2_log_wait_commit(sbi->s_journal,
5182 							   target);
5183 		}
5184 	} else if (wait && test_opt(sb, BARRIER))
5185 		needs_barrier = true;
5186 	if (needs_barrier) {
5187 		int err;
5188 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5189 		if (!ret)
5190 			ret = err;
5191 	}
5192 
5193 	return ret;
5194 }
5195 
5196 /*
5197  * LVM calls this function before a (read-only) snapshot is created.  This
5198  * gives us a chance to flush the journal completely and mark the fs clean.
5199  *
5200  * Note that only this function cannot bring a filesystem to be in a clean
5201  * state independently. It relies on upper layer to stop all data & metadata
5202  * modifications.
5203  */
5204 static int ext4_freeze(struct super_block *sb)
5205 {
5206 	int error = 0;
5207 	journal_t *journal;
5208 
5209 	if (sb_rdonly(sb))
5210 		return 0;
5211 
5212 	journal = EXT4_SB(sb)->s_journal;
5213 
5214 	if (journal) {
5215 		/* Now we set up the journal barrier. */
5216 		jbd2_journal_lock_updates(journal);
5217 
5218 		/*
5219 		 * Don't clear the needs_recovery flag if we failed to
5220 		 * flush the journal.
5221 		 */
5222 		error = jbd2_journal_flush(journal);
5223 		if (error < 0)
5224 			goto out;
5225 
5226 		/* Journal blocked and flushed, clear needs_recovery flag. */
5227 		ext4_clear_feature_journal_needs_recovery(sb);
5228 	}
5229 
5230 	error = ext4_commit_super(sb, 1);
5231 out:
5232 	if (journal)
5233 		/* we rely on upper layer to stop further updates */
5234 		jbd2_journal_unlock_updates(journal);
5235 	return error;
5236 }
5237 
5238 /*
5239  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5240  * flag here, even though the filesystem is not technically dirty yet.
5241  */
5242 static int ext4_unfreeze(struct super_block *sb)
5243 {
5244 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5245 		return 0;
5246 
5247 	if (EXT4_SB(sb)->s_journal) {
5248 		/* Reset the needs_recovery flag before the fs is unlocked. */
5249 		ext4_set_feature_journal_needs_recovery(sb);
5250 	}
5251 
5252 	ext4_commit_super(sb, 1);
5253 	return 0;
5254 }
5255 
5256 /*
5257  * Structure to save mount options for ext4_remount's benefit
5258  */
5259 struct ext4_mount_options {
5260 	unsigned long s_mount_opt;
5261 	unsigned long s_mount_opt2;
5262 	kuid_t s_resuid;
5263 	kgid_t s_resgid;
5264 	unsigned long s_commit_interval;
5265 	u32 s_min_batch_time, s_max_batch_time;
5266 #ifdef CONFIG_QUOTA
5267 	int s_jquota_fmt;
5268 	char *s_qf_names[EXT4_MAXQUOTAS];
5269 #endif
5270 };
5271 
5272 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5273 {
5274 	struct ext4_super_block *es;
5275 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5276 	unsigned long old_sb_flags;
5277 	struct ext4_mount_options old_opts;
5278 	int enable_quota = 0;
5279 	ext4_group_t g;
5280 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5281 	int err = 0;
5282 #ifdef CONFIG_QUOTA
5283 	int i, j;
5284 	char *to_free[EXT4_MAXQUOTAS];
5285 #endif
5286 	char *orig_data = kstrdup(data, GFP_KERNEL);
5287 
5288 	if (data && !orig_data)
5289 		return -ENOMEM;
5290 
5291 	/* Store the original options */
5292 	old_sb_flags = sb->s_flags;
5293 	old_opts.s_mount_opt = sbi->s_mount_opt;
5294 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5295 	old_opts.s_resuid = sbi->s_resuid;
5296 	old_opts.s_resgid = sbi->s_resgid;
5297 	old_opts.s_commit_interval = sbi->s_commit_interval;
5298 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5299 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5300 #ifdef CONFIG_QUOTA
5301 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5302 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5303 		if (sbi->s_qf_names[i]) {
5304 			char *qf_name = get_qf_name(sb, sbi, i);
5305 
5306 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5307 			if (!old_opts.s_qf_names[i]) {
5308 				for (j = 0; j < i; j++)
5309 					kfree(old_opts.s_qf_names[j]);
5310 				kfree(orig_data);
5311 				return -ENOMEM;
5312 			}
5313 		} else
5314 			old_opts.s_qf_names[i] = NULL;
5315 #endif
5316 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5317 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5318 
5319 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5320 		err = -EINVAL;
5321 		goto restore_opts;
5322 	}
5323 
5324 	ext4_clamp_want_extra_isize(sb);
5325 
5326 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5327 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5328 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5329 			 "during remount not supported; ignoring");
5330 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5331 	}
5332 
5333 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5334 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5335 			ext4_msg(sb, KERN_ERR, "can't mount with "
5336 				 "both data=journal and delalloc");
5337 			err = -EINVAL;
5338 			goto restore_opts;
5339 		}
5340 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5341 			ext4_msg(sb, KERN_ERR, "can't mount with "
5342 				 "both data=journal and dioread_nolock");
5343 			err = -EINVAL;
5344 			goto restore_opts;
5345 		}
5346 		if (test_opt(sb, DAX)) {
5347 			ext4_msg(sb, KERN_ERR, "can't mount with "
5348 				 "both data=journal and dax");
5349 			err = -EINVAL;
5350 			goto restore_opts;
5351 		}
5352 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5353 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5354 			ext4_msg(sb, KERN_ERR, "can't mount with "
5355 				"journal_async_commit in data=ordered mode");
5356 			err = -EINVAL;
5357 			goto restore_opts;
5358 		}
5359 	}
5360 
5361 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5362 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5363 		err = -EINVAL;
5364 		goto restore_opts;
5365 	}
5366 
5367 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5368 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5369 			"dax flag with busy inodes while remounting");
5370 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5371 	}
5372 
5373 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5374 		ext4_abort(sb, "Abort forced by user");
5375 
5376 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5377 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5378 
5379 	es = sbi->s_es;
5380 
5381 	if (sbi->s_journal) {
5382 		ext4_init_journal_params(sb, sbi->s_journal);
5383 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5384 	}
5385 
5386 	if (*flags & SB_LAZYTIME)
5387 		sb->s_flags |= SB_LAZYTIME;
5388 
5389 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5390 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5391 			err = -EROFS;
5392 			goto restore_opts;
5393 		}
5394 
5395 		if (*flags & SB_RDONLY) {
5396 			err = sync_filesystem(sb);
5397 			if (err < 0)
5398 				goto restore_opts;
5399 			err = dquot_suspend(sb, -1);
5400 			if (err < 0)
5401 				goto restore_opts;
5402 
5403 			/*
5404 			 * First of all, the unconditional stuff we have to do
5405 			 * to disable replay of the journal when we next remount
5406 			 */
5407 			sb->s_flags |= SB_RDONLY;
5408 
5409 			/*
5410 			 * OK, test if we are remounting a valid rw partition
5411 			 * readonly, and if so set the rdonly flag and then
5412 			 * mark the partition as valid again.
5413 			 */
5414 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5415 			    (sbi->s_mount_state & EXT4_VALID_FS))
5416 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5417 
5418 			if (sbi->s_journal)
5419 				ext4_mark_recovery_complete(sb, es);
5420 			if (sbi->s_mmp_tsk)
5421 				kthread_stop(sbi->s_mmp_tsk);
5422 		} else {
5423 			/* Make sure we can mount this feature set readwrite */
5424 			if (ext4_has_feature_readonly(sb) ||
5425 			    !ext4_feature_set_ok(sb, 0)) {
5426 				err = -EROFS;
5427 				goto restore_opts;
5428 			}
5429 			/*
5430 			 * Make sure the group descriptor checksums
5431 			 * are sane.  If they aren't, refuse to remount r/w.
5432 			 */
5433 			for (g = 0; g < sbi->s_groups_count; g++) {
5434 				struct ext4_group_desc *gdp =
5435 					ext4_get_group_desc(sb, g, NULL);
5436 
5437 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5438 					ext4_msg(sb, KERN_ERR,
5439 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5440 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5441 					       le16_to_cpu(gdp->bg_checksum));
5442 					err = -EFSBADCRC;
5443 					goto restore_opts;
5444 				}
5445 			}
5446 
5447 			/*
5448 			 * If we have an unprocessed orphan list hanging
5449 			 * around from a previously readonly bdev mount,
5450 			 * require a full umount/remount for now.
5451 			 */
5452 			if (es->s_last_orphan) {
5453 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5454 				       "remount RDWR because of unprocessed "
5455 				       "orphan inode list.  Please "
5456 				       "umount/remount instead");
5457 				err = -EINVAL;
5458 				goto restore_opts;
5459 			}
5460 
5461 			/*
5462 			 * Mounting a RDONLY partition read-write, so reread
5463 			 * and store the current valid flag.  (It may have
5464 			 * been changed by e2fsck since we originally mounted
5465 			 * the partition.)
5466 			 */
5467 			if (sbi->s_journal)
5468 				ext4_clear_journal_err(sb, es);
5469 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5470 
5471 			err = ext4_setup_super(sb, es, 0);
5472 			if (err)
5473 				goto restore_opts;
5474 
5475 			sb->s_flags &= ~SB_RDONLY;
5476 			if (ext4_has_feature_mmp(sb))
5477 				if (ext4_multi_mount_protect(sb,
5478 						le64_to_cpu(es->s_mmp_block))) {
5479 					err = -EROFS;
5480 					goto restore_opts;
5481 				}
5482 			enable_quota = 1;
5483 		}
5484 	}
5485 
5486 	/*
5487 	 * Reinitialize lazy itable initialization thread based on
5488 	 * current settings
5489 	 */
5490 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5491 		ext4_unregister_li_request(sb);
5492 	else {
5493 		ext4_group_t first_not_zeroed;
5494 		first_not_zeroed = ext4_has_uninit_itable(sb);
5495 		ext4_register_li_request(sb, first_not_zeroed);
5496 	}
5497 
5498 	ext4_setup_system_zone(sb);
5499 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5500 		err = ext4_commit_super(sb, 1);
5501 		if (err)
5502 			goto restore_opts;
5503 	}
5504 
5505 #ifdef CONFIG_QUOTA
5506 	/* Release old quota file names */
5507 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5508 		kfree(old_opts.s_qf_names[i]);
5509 	if (enable_quota) {
5510 		if (sb_any_quota_suspended(sb))
5511 			dquot_resume(sb, -1);
5512 		else if (ext4_has_feature_quota(sb)) {
5513 			err = ext4_enable_quotas(sb);
5514 			if (err)
5515 				goto restore_opts;
5516 		}
5517 	}
5518 #endif
5519 
5520 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5521 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5522 	kfree(orig_data);
5523 	return 0;
5524 
5525 restore_opts:
5526 	sb->s_flags = old_sb_flags;
5527 	sbi->s_mount_opt = old_opts.s_mount_opt;
5528 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5529 	sbi->s_resuid = old_opts.s_resuid;
5530 	sbi->s_resgid = old_opts.s_resgid;
5531 	sbi->s_commit_interval = old_opts.s_commit_interval;
5532 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5533 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5534 #ifdef CONFIG_QUOTA
5535 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5536 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5537 		to_free[i] = get_qf_name(sb, sbi, i);
5538 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5539 	}
5540 	synchronize_rcu();
5541 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5542 		kfree(to_free[i]);
5543 #endif
5544 	kfree(orig_data);
5545 	return err;
5546 }
5547 
5548 #ifdef CONFIG_QUOTA
5549 static int ext4_statfs_project(struct super_block *sb,
5550 			       kprojid_t projid, struct kstatfs *buf)
5551 {
5552 	struct kqid qid;
5553 	struct dquot *dquot;
5554 	u64 limit;
5555 	u64 curblock;
5556 
5557 	qid = make_kqid_projid(projid);
5558 	dquot = dqget(sb, qid);
5559 	if (IS_ERR(dquot))
5560 		return PTR_ERR(dquot);
5561 	spin_lock(&dquot->dq_dqb_lock);
5562 
5563 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5564 		 dquot->dq_dqb.dqb_bsoftlimit :
5565 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5566 	if (limit && buf->f_blocks > limit) {
5567 		curblock = (dquot->dq_dqb.dqb_curspace +
5568 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5569 		buf->f_blocks = limit;
5570 		buf->f_bfree = buf->f_bavail =
5571 			(buf->f_blocks > curblock) ?
5572 			 (buf->f_blocks - curblock) : 0;
5573 	}
5574 
5575 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5576 		dquot->dq_dqb.dqb_isoftlimit :
5577 		dquot->dq_dqb.dqb_ihardlimit;
5578 	if (limit && buf->f_files > limit) {
5579 		buf->f_files = limit;
5580 		buf->f_ffree =
5581 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5582 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5583 	}
5584 
5585 	spin_unlock(&dquot->dq_dqb_lock);
5586 	dqput(dquot);
5587 	return 0;
5588 }
5589 #endif
5590 
5591 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5592 {
5593 	struct super_block *sb = dentry->d_sb;
5594 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5595 	struct ext4_super_block *es = sbi->s_es;
5596 	ext4_fsblk_t overhead = 0, resv_blocks;
5597 	u64 fsid;
5598 	s64 bfree;
5599 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5600 
5601 	if (!test_opt(sb, MINIX_DF))
5602 		overhead = sbi->s_overhead;
5603 
5604 	buf->f_type = EXT4_SUPER_MAGIC;
5605 	buf->f_bsize = sb->s_blocksize;
5606 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5607 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5608 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5609 	/* prevent underflow in case that few free space is available */
5610 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5611 	buf->f_bavail = buf->f_bfree -
5612 			(ext4_r_blocks_count(es) + resv_blocks);
5613 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5614 		buf->f_bavail = 0;
5615 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5616 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5617 	buf->f_namelen = EXT4_NAME_LEN;
5618 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5619 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5620 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5621 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5622 
5623 #ifdef CONFIG_QUOTA
5624 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5625 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5626 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5627 #endif
5628 	return 0;
5629 }
5630 
5631 
5632 #ifdef CONFIG_QUOTA
5633 
5634 /*
5635  * Helper functions so that transaction is started before we acquire dqio_sem
5636  * to keep correct lock ordering of transaction > dqio_sem
5637  */
5638 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5639 {
5640 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5641 }
5642 
5643 static int ext4_write_dquot(struct dquot *dquot)
5644 {
5645 	int ret, err;
5646 	handle_t *handle;
5647 	struct inode *inode;
5648 
5649 	inode = dquot_to_inode(dquot);
5650 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5651 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5652 	if (IS_ERR(handle))
5653 		return PTR_ERR(handle);
5654 	ret = dquot_commit(dquot);
5655 	err = ext4_journal_stop(handle);
5656 	if (!ret)
5657 		ret = err;
5658 	return ret;
5659 }
5660 
5661 static int ext4_acquire_dquot(struct dquot *dquot)
5662 {
5663 	int ret, err;
5664 	handle_t *handle;
5665 
5666 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5667 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5668 	if (IS_ERR(handle))
5669 		return PTR_ERR(handle);
5670 	ret = dquot_acquire(dquot);
5671 	err = ext4_journal_stop(handle);
5672 	if (!ret)
5673 		ret = err;
5674 	return ret;
5675 }
5676 
5677 static int ext4_release_dquot(struct dquot *dquot)
5678 {
5679 	int ret, err;
5680 	handle_t *handle;
5681 
5682 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5683 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5684 	if (IS_ERR(handle)) {
5685 		/* Release dquot anyway to avoid endless cycle in dqput() */
5686 		dquot_release(dquot);
5687 		return PTR_ERR(handle);
5688 	}
5689 	ret = dquot_release(dquot);
5690 	err = ext4_journal_stop(handle);
5691 	if (!ret)
5692 		ret = err;
5693 	return ret;
5694 }
5695 
5696 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5697 {
5698 	struct super_block *sb = dquot->dq_sb;
5699 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5700 
5701 	/* Are we journaling quotas? */
5702 	if (ext4_has_feature_quota(sb) ||
5703 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5704 		dquot_mark_dquot_dirty(dquot);
5705 		return ext4_write_dquot(dquot);
5706 	} else {
5707 		return dquot_mark_dquot_dirty(dquot);
5708 	}
5709 }
5710 
5711 static int ext4_write_info(struct super_block *sb, int type)
5712 {
5713 	int ret, err;
5714 	handle_t *handle;
5715 
5716 	/* Data block + inode block */
5717 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5718 	if (IS_ERR(handle))
5719 		return PTR_ERR(handle);
5720 	ret = dquot_commit_info(sb, type);
5721 	err = ext4_journal_stop(handle);
5722 	if (!ret)
5723 		ret = err;
5724 	return ret;
5725 }
5726 
5727 /*
5728  * Turn on quotas during mount time - we need to find
5729  * the quota file and such...
5730  */
5731 static int ext4_quota_on_mount(struct super_block *sb, int type)
5732 {
5733 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5734 					EXT4_SB(sb)->s_jquota_fmt, type);
5735 }
5736 
5737 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5738 {
5739 	struct ext4_inode_info *ei = EXT4_I(inode);
5740 
5741 	/* The first argument of lockdep_set_subclass has to be
5742 	 * *exactly* the same as the argument to init_rwsem() --- in
5743 	 * this case, in init_once() --- or lockdep gets unhappy
5744 	 * because the name of the lock is set using the
5745 	 * stringification of the argument to init_rwsem().
5746 	 */
5747 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5748 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5749 }
5750 
5751 /*
5752  * Standard function to be called on quota_on
5753  */
5754 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5755 			 const struct path *path)
5756 {
5757 	int err;
5758 
5759 	if (!test_opt(sb, QUOTA))
5760 		return -EINVAL;
5761 
5762 	/* Quotafile not on the same filesystem? */
5763 	if (path->dentry->d_sb != sb)
5764 		return -EXDEV;
5765 	/* Journaling quota? */
5766 	if (EXT4_SB(sb)->s_qf_names[type]) {
5767 		/* Quotafile not in fs root? */
5768 		if (path->dentry->d_parent != sb->s_root)
5769 			ext4_msg(sb, KERN_WARNING,
5770 				"Quota file not on filesystem root. "
5771 				"Journaled quota will not work");
5772 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5773 	} else {
5774 		/*
5775 		 * Clear the flag just in case mount options changed since
5776 		 * last time.
5777 		 */
5778 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5779 	}
5780 
5781 	/*
5782 	 * When we journal data on quota file, we have to flush journal to see
5783 	 * all updates to the file when we bypass pagecache...
5784 	 */
5785 	if (EXT4_SB(sb)->s_journal &&
5786 	    ext4_should_journal_data(d_inode(path->dentry))) {
5787 		/*
5788 		 * We don't need to lock updates but journal_flush() could
5789 		 * otherwise be livelocked...
5790 		 */
5791 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5792 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5793 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5794 		if (err)
5795 			return err;
5796 	}
5797 
5798 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5799 	err = dquot_quota_on(sb, type, format_id, path);
5800 	if (err) {
5801 		lockdep_set_quota_inode(path->dentry->d_inode,
5802 					     I_DATA_SEM_NORMAL);
5803 	} else {
5804 		struct inode *inode = d_inode(path->dentry);
5805 		handle_t *handle;
5806 
5807 		/*
5808 		 * Set inode flags to prevent userspace from messing with quota
5809 		 * files. If this fails, we return success anyway since quotas
5810 		 * are already enabled and this is not a hard failure.
5811 		 */
5812 		inode_lock(inode);
5813 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5814 		if (IS_ERR(handle))
5815 			goto unlock_inode;
5816 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5817 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5818 				S_NOATIME | S_IMMUTABLE);
5819 		ext4_mark_inode_dirty(handle, inode);
5820 		ext4_journal_stop(handle);
5821 	unlock_inode:
5822 		inode_unlock(inode);
5823 	}
5824 	return err;
5825 }
5826 
5827 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5828 			     unsigned int flags)
5829 {
5830 	int err;
5831 	struct inode *qf_inode;
5832 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5833 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5834 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5835 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5836 	};
5837 
5838 	BUG_ON(!ext4_has_feature_quota(sb));
5839 
5840 	if (!qf_inums[type])
5841 		return -EPERM;
5842 
5843 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5844 	if (IS_ERR(qf_inode)) {
5845 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5846 		return PTR_ERR(qf_inode);
5847 	}
5848 
5849 	/* Don't account quota for quota files to avoid recursion */
5850 	qf_inode->i_flags |= S_NOQUOTA;
5851 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5852 	err = dquot_enable(qf_inode, type, format_id, flags);
5853 	if (err)
5854 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5855 	iput(qf_inode);
5856 
5857 	return err;
5858 }
5859 
5860 /* Enable usage tracking for all quota types. */
5861 static int ext4_enable_quotas(struct super_block *sb)
5862 {
5863 	int type, err = 0;
5864 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5865 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5866 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5867 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5868 	};
5869 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5870 		test_opt(sb, USRQUOTA),
5871 		test_opt(sb, GRPQUOTA),
5872 		test_opt(sb, PRJQUOTA),
5873 	};
5874 
5875 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5876 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5877 		if (qf_inums[type]) {
5878 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5879 				DQUOT_USAGE_ENABLED |
5880 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5881 			if (err) {
5882 				ext4_warning(sb,
5883 					"Failed to enable quota tracking "
5884 					"(type=%d, err=%d). Please run "
5885 					"e2fsck to fix.", type, err);
5886 				for (type--; type >= 0; type--)
5887 					dquot_quota_off(sb, type);
5888 
5889 				return err;
5890 			}
5891 		}
5892 	}
5893 	return 0;
5894 }
5895 
5896 static int ext4_quota_off(struct super_block *sb, int type)
5897 {
5898 	struct inode *inode = sb_dqopt(sb)->files[type];
5899 	handle_t *handle;
5900 	int err;
5901 
5902 	/* Force all delayed allocation blocks to be allocated.
5903 	 * Caller already holds s_umount sem */
5904 	if (test_opt(sb, DELALLOC))
5905 		sync_filesystem(sb);
5906 
5907 	if (!inode || !igrab(inode))
5908 		goto out;
5909 
5910 	err = dquot_quota_off(sb, type);
5911 	if (err || ext4_has_feature_quota(sb))
5912 		goto out_put;
5913 
5914 	inode_lock(inode);
5915 	/*
5916 	 * Update modification times of quota files when userspace can
5917 	 * start looking at them. If we fail, we return success anyway since
5918 	 * this is not a hard failure and quotas are already disabled.
5919 	 */
5920 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5921 	if (IS_ERR(handle))
5922 		goto out_unlock;
5923 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5924 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5925 	inode->i_mtime = inode->i_ctime = current_time(inode);
5926 	ext4_mark_inode_dirty(handle, inode);
5927 	ext4_journal_stop(handle);
5928 out_unlock:
5929 	inode_unlock(inode);
5930 out_put:
5931 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5932 	iput(inode);
5933 	return err;
5934 out:
5935 	return dquot_quota_off(sb, type);
5936 }
5937 
5938 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5939  * acquiring the locks... As quota files are never truncated and quota code
5940  * itself serializes the operations (and no one else should touch the files)
5941  * we don't have to be afraid of races */
5942 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5943 			       size_t len, loff_t off)
5944 {
5945 	struct inode *inode = sb_dqopt(sb)->files[type];
5946 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5947 	int offset = off & (sb->s_blocksize - 1);
5948 	int tocopy;
5949 	size_t toread;
5950 	struct buffer_head *bh;
5951 	loff_t i_size = i_size_read(inode);
5952 
5953 	if (off > i_size)
5954 		return 0;
5955 	if (off+len > i_size)
5956 		len = i_size-off;
5957 	toread = len;
5958 	while (toread > 0) {
5959 		tocopy = sb->s_blocksize - offset < toread ?
5960 				sb->s_blocksize - offset : toread;
5961 		bh = ext4_bread(NULL, inode, blk, 0);
5962 		if (IS_ERR(bh))
5963 			return PTR_ERR(bh);
5964 		if (!bh)	/* A hole? */
5965 			memset(data, 0, tocopy);
5966 		else
5967 			memcpy(data, bh->b_data+offset, tocopy);
5968 		brelse(bh);
5969 		offset = 0;
5970 		toread -= tocopy;
5971 		data += tocopy;
5972 		blk++;
5973 	}
5974 	return len;
5975 }
5976 
5977 /* Write to quotafile (we know the transaction is already started and has
5978  * enough credits) */
5979 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5980 				const char *data, size_t len, loff_t off)
5981 {
5982 	struct inode *inode = sb_dqopt(sb)->files[type];
5983 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5984 	int err, offset = off & (sb->s_blocksize - 1);
5985 	int retries = 0;
5986 	struct buffer_head *bh;
5987 	handle_t *handle = journal_current_handle();
5988 
5989 	if (EXT4_SB(sb)->s_journal && !handle) {
5990 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5991 			" cancelled because transaction is not started",
5992 			(unsigned long long)off, (unsigned long long)len);
5993 		return -EIO;
5994 	}
5995 	/*
5996 	 * Since we account only one data block in transaction credits,
5997 	 * then it is impossible to cross a block boundary.
5998 	 */
5999 	if (sb->s_blocksize - offset < len) {
6000 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
6001 			" cancelled because not block aligned",
6002 			(unsigned long long)off, (unsigned long long)len);
6003 		return -EIO;
6004 	}
6005 
6006 	do {
6007 		bh = ext4_bread(handle, inode, blk,
6008 				EXT4_GET_BLOCKS_CREATE |
6009 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
6010 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
6011 		 ext4_should_retry_alloc(inode->i_sb, &retries));
6012 	if (IS_ERR(bh))
6013 		return PTR_ERR(bh);
6014 	if (!bh)
6015 		goto out;
6016 	BUFFER_TRACE(bh, "get write access");
6017 	err = ext4_journal_get_write_access(handle, bh);
6018 	if (err) {
6019 		brelse(bh);
6020 		return err;
6021 	}
6022 	lock_buffer(bh);
6023 	memcpy(bh->b_data+offset, data, len);
6024 	flush_dcache_page(bh->b_page);
6025 	unlock_buffer(bh);
6026 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6027 	brelse(bh);
6028 out:
6029 	if (inode->i_size < off + len) {
6030 		i_size_write(inode, off + len);
6031 		EXT4_I(inode)->i_disksize = inode->i_size;
6032 		ext4_mark_inode_dirty(handle, inode);
6033 	}
6034 	return len;
6035 }
6036 
6037 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
6038 {
6039 	const struct quota_format_ops	*ops;
6040 
6041 	if (!sb_has_quota_loaded(sb, qid->type))
6042 		return -ESRCH;
6043 	ops = sb_dqopt(sb)->ops[qid->type];
6044 	if (!ops || !ops->get_next_id)
6045 		return -ENOSYS;
6046 	return dquot_get_next_id(sb, qid);
6047 }
6048 #endif
6049 
6050 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6051 		       const char *dev_name, void *data)
6052 {
6053 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6054 }
6055 
6056 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6057 static inline void register_as_ext2(void)
6058 {
6059 	int err = register_filesystem(&ext2_fs_type);
6060 	if (err)
6061 		printk(KERN_WARNING
6062 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6063 }
6064 
6065 static inline void unregister_as_ext2(void)
6066 {
6067 	unregister_filesystem(&ext2_fs_type);
6068 }
6069 
6070 static inline int ext2_feature_set_ok(struct super_block *sb)
6071 {
6072 	if (ext4_has_unknown_ext2_incompat_features(sb))
6073 		return 0;
6074 	if (sb_rdonly(sb))
6075 		return 1;
6076 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6077 		return 0;
6078 	return 1;
6079 }
6080 #else
6081 static inline void register_as_ext2(void) { }
6082 static inline void unregister_as_ext2(void) { }
6083 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6084 #endif
6085 
6086 static inline void register_as_ext3(void)
6087 {
6088 	int err = register_filesystem(&ext3_fs_type);
6089 	if (err)
6090 		printk(KERN_WARNING
6091 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6092 }
6093 
6094 static inline void unregister_as_ext3(void)
6095 {
6096 	unregister_filesystem(&ext3_fs_type);
6097 }
6098 
6099 static inline int ext3_feature_set_ok(struct super_block *sb)
6100 {
6101 	if (ext4_has_unknown_ext3_incompat_features(sb))
6102 		return 0;
6103 	if (!ext4_has_feature_journal(sb))
6104 		return 0;
6105 	if (sb_rdonly(sb))
6106 		return 1;
6107 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6108 		return 0;
6109 	return 1;
6110 }
6111 
6112 static struct file_system_type ext4_fs_type = {
6113 	.owner		= THIS_MODULE,
6114 	.name		= "ext4",
6115 	.mount		= ext4_mount,
6116 	.kill_sb	= kill_block_super,
6117 	.fs_flags	= FS_REQUIRES_DEV,
6118 };
6119 MODULE_ALIAS_FS("ext4");
6120 
6121 /* Shared across all ext4 file systems */
6122 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6123 
6124 static int __init ext4_init_fs(void)
6125 {
6126 	int i, err;
6127 
6128 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6129 	ext4_li_info = NULL;
6130 	mutex_init(&ext4_li_mtx);
6131 
6132 	/* Build-time check for flags consistency */
6133 	ext4_check_flag_values();
6134 
6135 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6136 		init_waitqueue_head(&ext4__ioend_wq[i]);
6137 
6138 	err = ext4_init_es();
6139 	if (err)
6140 		return err;
6141 
6142 	err = ext4_init_pending();
6143 	if (err)
6144 		goto out7;
6145 
6146 	err = ext4_init_post_read_processing();
6147 	if (err)
6148 		goto out6;
6149 
6150 	err = ext4_init_pageio();
6151 	if (err)
6152 		goto out5;
6153 
6154 	err = ext4_init_system_zone();
6155 	if (err)
6156 		goto out4;
6157 
6158 	err = ext4_init_sysfs();
6159 	if (err)
6160 		goto out3;
6161 
6162 	err = ext4_init_mballoc();
6163 	if (err)
6164 		goto out2;
6165 	err = init_inodecache();
6166 	if (err)
6167 		goto out1;
6168 	register_as_ext3();
6169 	register_as_ext2();
6170 	err = register_filesystem(&ext4_fs_type);
6171 	if (err)
6172 		goto out;
6173 
6174 	return 0;
6175 out:
6176 	unregister_as_ext2();
6177 	unregister_as_ext3();
6178 	destroy_inodecache();
6179 out1:
6180 	ext4_exit_mballoc();
6181 out2:
6182 	ext4_exit_sysfs();
6183 out3:
6184 	ext4_exit_system_zone();
6185 out4:
6186 	ext4_exit_pageio();
6187 out5:
6188 	ext4_exit_post_read_processing();
6189 out6:
6190 	ext4_exit_pending();
6191 out7:
6192 	ext4_exit_es();
6193 
6194 	return err;
6195 }
6196 
6197 static void __exit ext4_exit_fs(void)
6198 {
6199 	ext4_destroy_lazyinit_thread();
6200 	unregister_as_ext2();
6201 	unregister_as_ext3();
6202 	unregister_filesystem(&ext4_fs_type);
6203 	destroy_inodecache();
6204 	ext4_exit_mballoc();
6205 	ext4_exit_sysfs();
6206 	ext4_exit_system_zone();
6207 	ext4_exit_pageio();
6208 	ext4_exit_post_read_processing();
6209 	ext4_exit_es();
6210 	ext4_exit_pending();
6211 }
6212 
6213 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6214 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6215 MODULE_LICENSE("GPL");
6216 MODULE_SOFTDEP("pre: crc32c");
6217 module_init(ext4_init_fs)
6218 module_exit(ext4_exit_fs)
6219