xref: /openbmc/linux/fs/ext4/super.c (revision 78beef62)
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 const struct fscrypt_operations ext4_cryptops = {
1349 	.key_prefix		= "ext4:",
1350 	.get_context		= ext4_get_context,
1351 	.set_context		= ext4_set_context,
1352 	.dummy_context		= ext4_dummy_context,
1353 	.empty_dir		= ext4_empty_dir,
1354 	.max_namelen		= EXT4_NAME_LEN,
1355 };
1356 #endif
1357 
1358 #ifdef CONFIG_QUOTA
1359 static const char * const quotatypes[] = INITQFNAMES;
1360 #define QTYPE2NAME(t) (quotatypes[t])
1361 
1362 static int ext4_write_dquot(struct dquot *dquot);
1363 static int ext4_acquire_dquot(struct dquot *dquot);
1364 static int ext4_release_dquot(struct dquot *dquot);
1365 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1366 static int ext4_write_info(struct super_block *sb, int type);
1367 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1368 			 const struct path *path);
1369 static int ext4_quota_on_mount(struct super_block *sb, int type);
1370 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1371 			       size_t len, loff_t off);
1372 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1373 				const char *data, size_t len, loff_t off);
1374 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1375 			     unsigned int flags);
1376 static int ext4_enable_quotas(struct super_block *sb);
1377 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1378 
1379 static struct dquot **ext4_get_dquots(struct inode *inode)
1380 {
1381 	return EXT4_I(inode)->i_dquot;
1382 }
1383 
1384 static const struct dquot_operations ext4_quota_operations = {
1385 	.get_reserved_space	= ext4_get_reserved_space,
1386 	.write_dquot		= ext4_write_dquot,
1387 	.acquire_dquot		= ext4_acquire_dquot,
1388 	.release_dquot		= ext4_release_dquot,
1389 	.mark_dirty		= ext4_mark_dquot_dirty,
1390 	.write_info		= ext4_write_info,
1391 	.alloc_dquot		= dquot_alloc,
1392 	.destroy_dquot		= dquot_destroy,
1393 	.get_projid		= ext4_get_projid,
1394 	.get_inode_usage	= ext4_get_inode_usage,
1395 	.get_next_id		= ext4_get_next_id,
1396 };
1397 
1398 static const struct quotactl_ops ext4_qctl_operations = {
1399 	.quota_on	= ext4_quota_on,
1400 	.quota_off	= ext4_quota_off,
1401 	.quota_sync	= dquot_quota_sync,
1402 	.get_state	= dquot_get_state,
1403 	.set_info	= dquot_set_dqinfo,
1404 	.get_dqblk	= dquot_get_dqblk,
1405 	.set_dqblk	= dquot_set_dqblk,
1406 	.get_nextdqblk	= dquot_get_next_dqblk,
1407 };
1408 #endif
1409 
1410 static const struct super_operations ext4_sops = {
1411 	.alloc_inode	= ext4_alloc_inode,
1412 	.free_inode	= ext4_free_in_core_inode,
1413 	.destroy_inode	= ext4_destroy_inode,
1414 	.write_inode	= ext4_write_inode,
1415 	.dirty_inode	= ext4_dirty_inode,
1416 	.drop_inode	= ext4_drop_inode,
1417 	.evict_inode	= ext4_evict_inode,
1418 	.put_super	= ext4_put_super,
1419 	.sync_fs	= ext4_sync_fs,
1420 	.freeze_fs	= ext4_freeze,
1421 	.unfreeze_fs	= ext4_unfreeze,
1422 	.statfs		= ext4_statfs,
1423 	.remount_fs	= ext4_remount,
1424 	.show_options	= ext4_show_options,
1425 #ifdef CONFIG_QUOTA
1426 	.quota_read	= ext4_quota_read,
1427 	.quota_write	= ext4_quota_write,
1428 	.get_dquots	= ext4_get_dquots,
1429 #endif
1430 	.bdev_try_to_free_page = bdev_try_to_free_page,
1431 };
1432 
1433 static const struct export_operations ext4_export_ops = {
1434 	.fh_to_dentry = ext4_fh_to_dentry,
1435 	.fh_to_parent = ext4_fh_to_parent,
1436 	.get_parent = ext4_get_parent,
1437 	.commit_metadata = ext4_nfs_commit_metadata,
1438 };
1439 
1440 enum {
1441 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1442 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1443 	Opt_nouid32, Opt_debug, Opt_removed,
1444 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1445 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1446 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1447 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1448 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1449 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1450 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1451 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1452 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1453 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1454 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1455 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1456 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1457 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1458 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1459 	Opt_dioread_nolock, Opt_dioread_lock,
1460 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1461 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1462 };
1463 
1464 static const match_table_t tokens = {
1465 	{Opt_bsd_df, "bsddf"},
1466 	{Opt_minix_df, "minixdf"},
1467 	{Opt_grpid, "grpid"},
1468 	{Opt_grpid, "bsdgroups"},
1469 	{Opt_nogrpid, "nogrpid"},
1470 	{Opt_nogrpid, "sysvgroups"},
1471 	{Opt_resgid, "resgid=%u"},
1472 	{Opt_resuid, "resuid=%u"},
1473 	{Opt_sb, "sb=%u"},
1474 	{Opt_err_cont, "errors=continue"},
1475 	{Opt_err_panic, "errors=panic"},
1476 	{Opt_err_ro, "errors=remount-ro"},
1477 	{Opt_nouid32, "nouid32"},
1478 	{Opt_debug, "debug"},
1479 	{Opt_removed, "oldalloc"},
1480 	{Opt_removed, "orlov"},
1481 	{Opt_user_xattr, "user_xattr"},
1482 	{Opt_nouser_xattr, "nouser_xattr"},
1483 	{Opt_acl, "acl"},
1484 	{Opt_noacl, "noacl"},
1485 	{Opt_noload, "norecovery"},
1486 	{Opt_noload, "noload"},
1487 	{Opt_removed, "nobh"},
1488 	{Opt_removed, "bh"},
1489 	{Opt_commit, "commit=%u"},
1490 	{Opt_min_batch_time, "min_batch_time=%u"},
1491 	{Opt_max_batch_time, "max_batch_time=%u"},
1492 	{Opt_journal_dev, "journal_dev=%u"},
1493 	{Opt_journal_path, "journal_path=%s"},
1494 	{Opt_journal_checksum, "journal_checksum"},
1495 	{Opt_nojournal_checksum, "nojournal_checksum"},
1496 	{Opt_journal_async_commit, "journal_async_commit"},
1497 	{Opt_abort, "abort"},
1498 	{Opt_data_journal, "data=journal"},
1499 	{Opt_data_ordered, "data=ordered"},
1500 	{Opt_data_writeback, "data=writeback"},
1501 	{Opt_data_err_abort, "data_err=abort"},
1502 	{Opt_data_err_ignore, "data_err=ignore"},
1503 	{Opt_offusrjquota, "usrjquota="},
1504 	{Opt_usrjquota, "usrjquota=%s"},
1505 	{Opt_offgrpjquota, "grpjquota="},
1506 	{Opt_grpjquota, "grpjquota=%s"},
1507 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1508 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1509 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1510 	{Opt_grpquota, "grpquota"},
1511 	{Opt_noquota, "noquota"},
1512 	{Opt_quota, "quota"},
1513 	{Opt_usrquota, "usrquota"},
1514 	{Opt_prjquota, "prjquota"},
1515 	{Opt_barrier, "barrier=%u"},
1516 	{Opt_barrier, "barrier"},
1517 	{Opt_nobarrier, "nobarrier"},
1518 	{Opt_i_version, "i_version"},
1519 	{Opt_dax, "dax"},
1520 	{Opt_stripe, "stripe=%u"},
1521 	{Opt_delalloc, "delalloc"},
1522 	{Opt_warn_on_error, "warn_on_error"},
1523 	{Opt_nowarn_on_error, "nowarn_on_error"},
1524 	{Opt_lazytime, "lazytime"},
1525 	{Opt_nolazytime, "nolazytime"},
1526 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1527 	{Opt_nodelalloc, "nodelalloc"},
1528 	{Opt_removed, "mblk_io_submit"},
1529 	{Opt_removed, "nomblk_io_submit"},
1530 	{Opt_block_validity, "block_validity"},
1531 	{Opt_noblock_validity, "noblock_validity"},
1532 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1533 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1534 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1535 	{Opt_auto_da_alloc, "auto_da_alloc"},
1536 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1537 	{Opt_dioread_nolock, "dioread_nolock"},
1538 	{Opt_dioread_lock, "dioread_lock"},
1539 	{Opt_discard, "discard"},
1540 	{Opt_nodiscard, "nodiscard"},
1541 	{Opt_init_itable, "init_itable=%u"},
1542 	{Opt_init_itable, "init_itable"},
1543 	{Opt_noinit_itable, "noinit_itable"},
1544 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1545 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1546 	{Opt_nombcache, "nombcache"},
1547 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1548 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1549 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1550 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1551 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1552 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1553 	{Opt_err, NULL},
1554 };
1555 
1556 static ext4_fsblk_t get_sb_block(void **data)
1557 {
1558 	ext4_fsblk_t	sb_block;
1559 	char		*options = (char *) *data;
1560 
1561 	if (!options || strncmp(options, "sb=", 3) != 0)
1562 		return 1;	/* Default location */
1563 
1564 	options += 3;
1565 	/* TODO: use simple_strtoll with >32bit ext4 */
1566 	sb_block = simple_strtoul(options, &options, 0);
1567 	if (*options && *options != ',') {
1568 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1569 		       (char *) *data);
1570 		return 1;
1571 	}
1572 	if (*options == ',')
1573 		options++;
1574 	*data = (void *) options;
1575 
1576 	return sb_block;
1577 }
1578 
1579 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1580 static const char deprecated_msg[] =
1581 	"Mount option \"%s\" will be removed by %s\n"
1582 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1583 
1584 #ifdef CONFIG_QUOTA
1585 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1586 {
1587 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1588 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1589 	int ret = -1;
1590 
1591 	if (sb_any_quota_loaded(sb) && !old_qname) {
1592 		ext4_msg(sb, KERN_ERR,
1593 			"Cannot change journaled "
1594 			"quota options when quota turned on");
1595 		return -1;
1596 	}
1597 	if (ext4_has_feature_quota(sb)) {
1598 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1599 			 "ignored when QUOTA feature is enabled");
1600 		return 1;
1601 	}
1602 	qname = match_strdup(args);
1603 	if (!qname) {
1604 		ext4_msg(sb, KERN_ERR,
1605 			"Not enough memory for storing quotafile name");
1606 		return -1;
1607 	}
1608 	if (old_qname) {
1609 		if (strcmp(old_qname, qname) == 0)
1610 			ret = 1;
1611 		else
1612 			ext4_msg(sb, KERN_ERR,
1613 				 "%s quota file already specified",
1614 				 QTYPE2NAME(qtype));
1615 		goto errout;
1616 	}
1617 	if (strchr(qname, '/')) {
1618 		ext4_msg(sb, KERN_ERR,
1619 			"quotafile must be on filesystem root");
1620 		goto errout;
1621 	}
1622 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1623 	set_opt(sb, QUOTA);
1624 	return 1;
1625 errout:
1626 	kfree(qname);
1627 	return ret;
1628 }
1629 
1630 static int clear_qf_name(struct super_block *sb, int qtype)
1631 {
1632 
1633 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1634 	char *old_qname = get_qf_name(sb, sbi, qtype);
1635 
1636 	if (sb_any_quota_loaded(sb) && old_qname) {
1637 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1638 			" when quota turned on");
1639 		return -1;
1640 	}
1641 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1642 	synchronize_rcu();
1643 	kfree(old_qname);
1644 	return 1;
1645 }
1646 #endif
1647 
1648 #define MOPT_SET	0x0001
1649 #define MOPT_CLEAR	0x0002
1650 #define MOPT_NOSUPPORT	0x0004
1651 #define MOPT_EXPLICIT	0x0008
1652 #define MOPT_CLEAR_ERR	0x0010
1653 #define MOPT_GTE0	0x0020
1654 #ifdef CONFIG_QUOTA
1655 #define MOPT_Q		0
1656 #define MOPT_QFMT	0x0040
1657 #else
1658 #define MOPT_Q		MOPT_NOSUPPORT
1659 #define MOPT_QFMT	MOPT_NOSUPPORT
1660 #endif
1661 #define MOPT_DATAJ	0x0080
1662 #define MOPT_NO_EXT2	0x0100
1663 #define MOPT_NO_EXT3	0x0200
1664 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1665 #define MOPT_STRING	0x0400
1666 
1667 static const struct mount_opts {
1668 	int	token;
1669 	int	mount_opt;
1670 	int	flags;
1671 } ext4_mount_opts[] = {
1672 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1673 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1674 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1675 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1676 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1677 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1678 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1679 	 MOPT_EXT4_ONLY | MOPT_SET},
1680 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1681 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1682 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1683 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1684 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1685 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1686 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1687 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1688 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1689 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1690 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1691 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1692 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1693 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1694 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1695 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1696 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1697 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1698 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1699 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1700 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1701 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1702 	 MOPT_NO_EXT2},
1703 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1704 	 MOPT_NO_EXT2},
1705 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1706 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1707 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1708 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1709 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1710 	{Opt_commit, 0, MOPT_GTE0},
1711 	{Opt_max_batch_time, 0, MOPT_GTE0},
1712 	{Opt_min_batch_time, 0, MOPT_GTE0},
1713 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1714 	{Opt_init_itable, 0, MOPT_GTE0},
1715 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1716 	{Opt_stripe, 0, MOPT_GTE0},
1717 	{Opt_resuid, 0, MOPT_GTE0},
1718 	{Opt_resgid, 0, MOPT_GTE0},
1719 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1720 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1721 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1722 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1723 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1724 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1725 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1726 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1727 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1728 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1729 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1730 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1731 #else
1732 	{Opt_acl, 0, MOPT_NOSUPPORT},
1733 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1734 #endif
1735 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1736 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1737 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1738 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1739 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1740 							MOPT_SET | MOPT_Q},
1741 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1742 							MOPT_SET | MOPT_Q},
1743 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1744 							MOPT_SET | MOPT_Q},
1745 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1746 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1747 							MOPT_CLEAR | MOPT_Q},
1748 	{Opt_usrjquota, 0, MOPT_Q},
1749 	{Opt_grpjquota, 0, MOPT_Q},
1750 	{Opt_offusrjquota, 0, MOPT_Q},
1751 	{Opt_offgrpjquota, 0, MOPT_Q},
1752 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1753 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1754 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1755 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1756 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1757 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1758 	{Opt_err, 0, 0}
1759 };
1760 
1761 #ifdef CONFIG_UNICODE
1762 static const struct ext4_sb_encodings {
1763 	__u16 magic;
1764 	char *name;
1765 	char *version;
1766 } ext4_sb_encoding_map[] = {
1767 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1768 };
1769 
1770 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1771 				 const struct ext4_sb_encodings **encoding,
1772 				 __u16 *flags)
1773 {
1774 	__u16 magic = le16_to_cpu(es->s_encoding);
1775 	int i;
1776 
1777 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1778 		if (magic == ext4_sb_encoding_map[i].magic)
1779 			break;
1780 
1781 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1782 		return -EINVAL;
1783 
1784 	*encoding = &ext4_sb_encoding_map[i];
1785 	*flags = le16_to_cpu(es->s_encoding_flags);
1786 
1787 	return 0;
1788 }
1789 #endif
1790 
1791 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1792 			    substring_t *args, unsigned long *journal_devnum,
1793 			    unsigned int *journal_ioprio, int is_remount)
1794 {
1795 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1796 	const struct mount_opts *m;
1797 	kuid_t uid;
1798 	kgid_t gid;
1799 	int arg = 0;
1800 
1801 #ifdef CONFIG_QUOTA
1802 	if (token == Opt_usrjquota)
1803 		return set_qf_name(sb, USRQUOTA, &args[0]);
1804 	else if (token == Opt_grpjquota)
1805 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1806 	else if (token == Opt_offusrjquota)
1807 		return clear_qf_name(sb, USRQUOTA);
1808 	else if (token == Opt_offgrpjquota)
1809 		return clear_qf_name(sb, GRPQUOTA);
1810 #endif
1811 	switch (token) {
1812 	case Opt_noacl:
1813 	case Opt_nouser_xattr:
1814 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1815 		break;
1816 	case Opt_sb:
1817 		return 1;	/* handled by get_sb_block() */
1818 	case Opt_removed:
1819 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1820 		return 1;
1821 	case Opt_abort:
1822 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1823 		return 1;
1824 	case Opt_i_version:
1825 		sb->s_flags |= SB_I_VERSION;
1826 		return 1;
1827 	case Opt_lazytime:
1828 		sb->s_flags |= SB_LAZYTIME;
1829 		return 1;
1830 	case Opt_nolazytime:
1831 		sb->s_flags &= ~SB_LAZYTIME;
1832 		return 1;
1833 	}
1834 
1835 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1836 		if (token == m->token)
1837 			break;
1838 
1839 	if (m->token == Opt_err) {
1840 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1841 			 "or missing value", opt);
1842 		return -1;
1843 	}
1844 
1845 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1846 		ext4_msg(sb, KERN_ERR,
1847 			 "Mount option \"%s\" incompatible with ext2", opt);
1848 		return -1;
1849 	}
1850 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1851 		ext4_msg(sb, KERN_ERR,
1852 			 "Mount option \"%s\" incompatible with ext3", opt);
1853 		return -1;
1854 	}
1855 
1856 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1857 		return -1;
1858 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1859 		return -1;
1860 	if (m->flags & MOPT_EXPLICIT) {
1861 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1862 			set_opt2(sb, EXPLICIT_DELALLOC);
1863 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1864 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1865 		} else
1866 			return -1;
1867 	}
1868 	if (m->flags & MOPT_CLEAR_ERR)
1869 		clear_opt(sb, ERRORS_MASK);
1870 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1871 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1872 			 "options when quota turned on");
1873 		return -1;
1874 	}
1875 
1876 	if (m->flags & MOPT_NOSUPPORT) {
1877 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1878 	} else if (token == Opt_commit) {
1879 		if (arg == 0)
1880 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1881 		sbi->s_commit_interval = HZ * arg;
1882 	} else if (token == Opt_debug_want_extra_isize) {
1883 		sbi->s_want_extra_isize = arg;
1884 	} else if (token == Opt_max_batch_time) {
1885 		sbi->s_max_batch_time = arg;
1886 	} else if (token == Opt_min_batch_time) {
1887 		sbi->s_min_batch_time = arg;
1888 	} else if (token == Opt_inode_readahead_blks) {
1889 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1890 			ext4_msg(sb, KERN_ERR,
1891 				 "EXT4-fs: inode_readahead_blks must be "
1892 				 "0 or a power of 2 smaller than 2^31");
1893 			return -1;
1894 		}
1895 		sbi->s_inode_readahead_blks = arg;
1896 	} else if (token == Opt_init_itable) {
1897 		set_opt(sb, INIT_INODE_TABLE);
1898 		if (!args->from)
1899 			arg = EXT4_DEF_LI_WAIT_MULT;
1900 		sbi->s_li_wait_mult = arg;
1901 	} else if (token == Opt_max_dir_size_kb) {
1902 		sbi->s_max_dir_size_kb = arg;
1903 	} else if (token == Opt_stripe) {
1904 		sbi->s_stripe = arg;
1905 	} else if (token == Opt_resuid) {
1906 		uid = make_kuid(current_user_ns(), arg);
1907 		if (!uid_valid(uid)) {
1908 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1909 			return -1;
1910 		}
1911 		sbi->s_resuid = uid;
1912 	} else if (token == Opt_resgid) {
1913 		gid = make_kgid(current_user_ns(), arg);
1914 		if (!gid_valid(gid)) {
1915 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1916 			return -1;
1917 		}
1918 		sbi->s_resgid = gid;
1919 	} else if (token == Opt_journal_dev) {
1920 		if (is_remount) {
1921 			ext4_msg(sb, KERN_ERR,
1922 				 "Cannot specify journal on remount");
1923 			return -1;
1924 		}
1925 		*journal_devnum = arg;
1926 	} else if (token == Opt_journal_path) {
1927 		char *journal_path;
1928 		struct inode *journal_inode;
1929 		struct path path;
1930 		int error;
1931 
1932 		if (is_remount) {
1933 			ext4_msg(sb, KERN_ERR,
1934 				 "Cannot specify journal on remount");
1935 			return -1;
1936 		}
1937 		journal_path = match_strdup(&args[0]);
1938 		if (!journal_path) {
1939 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1940 				"journal device string");
1941 			return -1;
1942 		}
1943 
1944 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1945 		if (error) {
1946 			ext4_msg(sb, KERN_ERR, "error: could not find "
1947 				"journal device path: error %d", error);
1948 			kfree(journal_path);
1949 			return -1;
1950 		}
1951 
1952 		journal_inode = d_inode(path.dentry);
1953 		if (!S_ISBLK(journal_inode->i_mode)) {
1954 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1955 				"is not a block device", journal_path);
1956 			path_put(&path);
1957 			kfree(journal_path);
1958 			return -1;
1959 		}
1960 
1961 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1962 		path_put(&path);
1963 		kfree(journal_path);
1964 	} else if (token == Opt_journal_ioprio) {
1965 		if (arg > 7) {
1966 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1967 				 " (must be 0-7)");
1968 			return -1;
1969 		}
1970 		*journal_ioprio =
1971 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1972 	} else if (token == Opt_test_dummy_encryption) {
1973 #ifdef CONFIG_FS_ENCRYPTION
1974 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1975 		ext4_msg(sb, KERN_WARNING,
1976 			 "Test dummy encryption mode enabled");
1977 #else
1978 		ext4_msg(sb, KERN_WARNING,
1979 			 "Test dummy encryption mount option ignored");
1980 #endif
1981 	} else if (m->flags & MOPT_DATAJ) {
1982 		if (is_remount) {
1983 			if (!sbi->s_journal)
1984 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1985 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1986 				ext4_msg(sb, KERN_ERR,
1987 					 "Cannot change data mode on remount");
1988 				return -1;
1989 			}
1990 		} else {
1991 			clear_opt(sb, DATA_FLAGS);
1992 			sbi->s_mount_opt |= m->mount_opt;
1993 		}
1994 #ifdef CONFIG_QUOTA
1995 	} else if (m->flags & MOPT_QFMT) {
1996 		if (sb_any_quota_loaded(sb) &&
1997 		    sbi->s_jquota_fmt != m->mount_opt) {
1998 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1999 				 "quota options when quota turned on");
2000 			return -1;
2001 		}
2002 		if (ext4_has_feature_quota(sb)) {
2003 			ext4_msg(sb, KERN_INFO,
2004 				 "Quota format mount options ignored "
2005 				 "when QUOTA feature is enabled");
2006 			return 1;
2007 		}
2008 		sbi->s_jquota_fmt = m->mount_opt;
2009 #endif
2010 	} else if (token == Opt_dax) {
2011 #ifdef CONFIG_FS_DAX
2012 		ext4_msg(sb, KERN_WARNING,
2013 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2014 		sbi->s_mount_opt |= m->mount_opt;
2015 #else
2016 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2017 		return -1;
2018 #endif
2019 	} else if (token == Opt_data_err_abort) {
2020 		sbi->s_mount_opt |= m->mount_opt;
2021 	} else if (token == Opt_data_err_ignore) {
2022 		sbi->s_mount_opt &= ~m->mount_opt;
2023 	} else {
2024 		if (!args->from)
2025 			arg = 1;
2026 		if (m->flags & MOPT_CLEAR)
2027 			arg = !arg;
2028 		else if (unlikely(!(m->flags & MOPT_SET))) {
2029 			ext4_msg(sb, KERN_WARNING,
2030 				 "buggy handling of option %s", opt);
2031 			WARN_ON(1);
2032 			return -1;
2033 		}
2034 		if (arg != 0)
2035 			sbi->s_mount_opt |= m->mount_opt;
2036 		else
2037 			sbi->s_mount_opt &= ~m->mount_opt;
2038 	}
2039 	return 1;
2040 }
2041 
2042 static int parse_options(char *options, struct super_block *sb,
2043 			 unsigned long *journal_devnum,
2044 			 unsigned int *journal_ioprio,
2045 			 int is_remount)
2046 {
2047 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2048 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2049 	substring_t args[MAX_OPT_ARGS];
2050 	int token;
2051 
2052 	if (!options)
2053 		return 1;
2054 
2055 	while ((p = strsep(&options, ",")) != NULL) {
2056 		if (!*p)
2057 			continue;
2058 		/*
2059 		 * Initialize args struct so we know whether arg was
2060 		 * found; some options take optional arguments.
2061 		 */
2062 		args[0].to = args[0].from = NULL;
2063 		token = match_token(p, tokens, args);
2064 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2065 				     journal_ioprio, is_remount) < 0)
2066 			return 0;
2067 	}
2068 #ifdef CONFIG_QUOTA
2069 	/*
2070 	 * We do the test below only for project quotas. 'usrquota' and
2071 	 * 'grpquota' mount options are allowed even without quota feature
2072 	 * to support legacy quotas in quota files.
2073 	 */
2074 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2075 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2076 			 "Cannot enable project quota enforcement.");
2077 		return 0;
2078 	}
2079 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2080 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2081 	if (usr_qf_name || grp_qf_name) {
2082 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2083 			clear_opt(sb, USRQUOTA);
2084 
2085 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2086 			clear_opt(sb, GRPQUOTA);
2087 
2088 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2089 			ext4_msg(sb, KERN_ERR, "old and new quota "
2090 					"format mixing");
2091 			return 0;
2092 		}
2093 
2094 		if (!sbi->s_jquota_fmt) {
2095 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2096 					"not specified");
2097 			return 0;
2098 		}
2099 	}
2100 #endif
2101 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2102 		int blocksize =
2103 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2104 
2105 		if (blocksize < PAGE_SIZE) {
2106 			ext4_msg(sb, KERN_ERR, "can't mount with "
2107 				 "dioread_nolock if block size != PAGE_SIZE");
2108 			return 0;
2109 		}
2110 	}
2111 	return 1;
2112 }
2113 
2114 static inline void ext4_show_quota_options(struct seq_file *seq,
2115 					   struct super_block *sb)
2116 {
2117 #if defined(CONFIG_QUOTA)
2118 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2119 	char *usr_qf_name, *grp_qf_name;
2120 
2121 	if (sbi->s_jquota_fmt) {
2122 		char *fmtname = "";
2123 
2124 		switch (sbi->s_jquota_fmt) {
2125 		case QFMT_VFS_OLD:
2126 			fmtname = "vfsold";
2127 			break;
2128 		case QFMT_VFS_V0:
2129 			fmtname = "vfsv0";
2130 			break;
2131 		case QFMT_VFS_V1:
2132 			fmtname = "vfsv1";
2133 			break;
2134 		}
2135 		seq_printf(seq, ",jqfmt=%s", fmtname);
2136 	}
2137 
2138 	rcu_read_lock();
2139 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2140 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2141 	if (usr_qf_name)
2142 		seq_show_option(seq, "usrjquota", usr_qf_name);
2143 	if (grp_qf_name)
2144 		seq_show_option(seq, "grpjquota", grp_qf_name);
2145 	rcu_read_unlock();
2146 #endif
2147 }
2148 
2149 static const char *token2str(int token)
2150 {
2151 	const struct match_token *t;
2152 
2153 	for (t = tokens; t->token != Opt_err; t++)
2154 		if (t->token == token && !strchr(t->pattern, '='))
2155 			break;
2156 	return t->pattern;
2157 }
2158 
2159 /*
2160  * Show an option if
2161  *  - it's set to a non-default value OR
2162  *  - if the per-sb default is different from the global default
2163  */
2164 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2165 			      int nodefs)
2166 {
2167 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2168 	struct ext4_super_block *es = sbi->s_es;
2169 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2170 	const struct mount_opts *m;
2171 	char sep = nodefs ? '\n' : ',';
2172 
2173 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2174 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2175 
2176 	if (sbi->s_sb_block != 1)
2177 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2178 
2179 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2180 		int want_set = m->flags & MOPT_SET;
2181 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2182 		    (m->flags & MOPT_CLEAR_ERR))
2183 			continue;
2184 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2185 			continue; /* skip if same as the default */
2186 		if ((want_set &&
2187 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2188 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2189 			continue; /* select Opt_noFoo vs Opt_Foo */
2190 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2191 	}
2192 
2193 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2194 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2195 		SEQ_OPTS_PRINT("resuid=%u",
2196 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2197 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2198 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2199 		SEQ_OPTS_PRINT("resgid=%u",
2200 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2201 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2202 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2203 		SEQ_OPTS_PUTS("errors=remount-ro");
2204 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2205 		SEQ_OPTS_PUTS("errors=continue");
2206 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2207 		SEQ_OPTS_PUTS("errors=panic");
2208 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2209 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2210 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2211 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2212 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2213 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2214 	if (sb->s_flags & SB_I_VERSION)
2215 		SEQ_OPTS_PUTS("i_version");
2216 	if (nodefs || sbi->s_stripe)
2217 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2218 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2219 			(sbi->s_mount_opt ^ def_mount_opt)) {
2220 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2221 			SEQ_OPTS_PUTS("data=journal");
2222 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2223 			SEQ_OPTS_PUTS("data=ordered");
2224 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2225 			SEQ_OPTS_PUTS("data=writeback");
2226 	}
2227 	if (nodefs ||
2228 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2229 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2230 			       sbi->s_inode_readahead_blks);
2231 
2232 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2233 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2234 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2235 	if (nodefs || sbi->s_max_dir_size_kb)
2236 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2237 	if (test_opt(sb, DATA_ERR_ABORT))
2238 		SEQ_OPTS_PUTS("data_err=abort");
2239 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2240 		SEQ_OPTS_PUTS("test_dummy_encryption");
2241 
2242 	ext4_show_quota_options(seq, sb);
2243 	return 0;
2244 }
2245 
2246 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2247 {
2248 	return _ext4_show_options(seq, root->d_sb, 0);
2249 }
2250 
2251 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2252 {
2253 	struct super_block *sb = seq->private;
2254 	int rc;
2255 
2256 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2257 	rc = _ext4_show_options(seq, sb, 1);
2258 	seq_puts(seq, "\n");
2259 	return rc;
2260 }
2261 
2262 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2263 			    int read_only)
2264 {
2265 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2266 	int err = 0;
2267 
2268 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2269 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2270 			 "forcing read-only mode");
2271 		err = -EROFS;
2272 	}
2273 	if (read_only)
2274 		goto done;
2275 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2276 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2277 			 "running e2fsck is recommended");
2278 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2279 		ext4_msg(sb, KERN_WARNING,
2280 			 "warning: mounting fs with errors, "
2281 			 "running e2fsck is recommended");
2282 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2283 		 le16_to_cpu(es->s_mnt_count) >=
2284 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2285 		ext4_msg(sb, KERN_WARNING,
2286 			 "warning: maximal mount count reached, "
2287 			 "running e2fsck is recommended");
2288 	else if (le32_to_cpu(es->s_checkinterval) &&
2289 		 (ext4_get_tstamp(es, s_lastcheck) +
2290 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2291 		ext4_msg(sb, KERN_WARNING,
2292 			 "warning: checktime reached, "
2293 			 "running e2fsck is recommended");
2294 	if (!sbi->s_journal)
2295 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2296 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2297 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2298 	le16_add_cpu(&es->s_mnt_count, 1);
2299 	ext4_update_tstamp(es, s_mtime);
2300 	if (sbi->s_journal)
2301 		ext4_set_feature_journal_needs_recovery(sb);
2302 
2303 	err = ext4_commit_super(sb, 1);
2304 done:
2305 	if (test_opt(sb, DEBUG))
2306 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2307 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2308 			sb->s_blocksize,
2309 			sbi->s_groups_count,
2310 			EXT4_BLOCKS_PER_GROUP(sb),
2311 			EXT4_INODES_PER_GROUP(sb),
2312 			sbi->s_mount_opt, sbi->s_mount_opt2);
2313 
2314 	cleancache_init_fs(sb);
2315 	return err;
2316 }
2317 
2318 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2319 {
2320 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2321 	struct flex_groups *new_groups;
2322 	int size;
2323 
2324 	if (!sbi->s_log_groups_per_flex)
2325 		return 0;
2326 
2327 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2328 	if (size <= sbi->s_flex_groups_allocated)
2329 		return 0;
2330 
2331 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2332 	new_groups = kvzalloc(size, GFP_KERNEL);
2333 	if (!new_groups) {
2334 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2335 			 size / (int) sizeof(struct flex_groups));
2336 		return -ENOMEM;
2337 	}
2338 
2339 	if (sbi->s_flex_groups) {
2340 		memcpy(new_groups, sbi->s_flex_groups,
2341 		       (sbi->s_flex_groups_allocated *
2342 			sizeof(struct flex_groups)));
2343 		kvfree(sbi->s_flex_groups);
2344 	}
2345 	sbi->s_flex_groups = new_groups;
2346 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2347 	return 0;
2348 }
2349 
2350 static int ext4_fill_flex_info(struct super_block *sb)
2351 {
2352 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2353 	struct ext4_group_desc *gdp = NULL;
2354 	ext4_group_t flex_group;
2355 	int i, err;
2356 
2357 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2358 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2359 		sbi->s_log_groups_per_flex = 0;
2360 		return 1;
2361 	}
2362 
2363 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2364 	if (err)
2365 		goto failed;
2366 
2367 	for (i = 0; i < sbi->s_groups_count; i++) {
2368 		gdp = ext4_get_group_desc(sb, i, NULL);
2369 
2370 		flex_group = ext4_flex_group(sbi, i);
2371 		atomic_add(ext4_free_inodes_count(sb, gdp),
2372 			   &sbi->s_flex_groups[flex_group].free_inodes);
2373 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2374 			     &sbi->s_flex_groups[flex_group].free_clusters);
2375 		atomic_add(ext4_used_dirs_count(sb, gdp),
2376 			   &sbi->s_flex_groups[flex_group].used_dirs);
2377 	}
2378 
2379 	return 1;
2380 failed:
2381 	return 0;
2382 }
2383 
2384 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2385 				   struct ext4_group_desc *gdp)
2386 {
2387 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2388 	__u16 crc = 0;
2389 	__le32 le_group = cpu_to_le32(block_group);
2390 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2391 
2392 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2393 		/* Use new metadata_csum algorithm */
2394 		__u32 csum32;
2395 		__u16 dummy_csum = 0;
2396 
2397 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2398 				     sizeof(le_group));
2399 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2400 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2401 				     sizeof(dummy_csum));
2402 		offset += sizeof(dummy_csum);
2403 		if (offset < sbi->s_desc_size)
2404 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2405 					     sbi->s_desc_size - offset);
2406 
2407 		crc = csum32 & 0xFFFF;
2408 		goto out;
2409 	}
2410 
2411 	/* old crc16 code */
2412 	if (!ext4_has_feature_gdt_csum(sb))
2413 		return 0;
2414 
2415 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2416 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2417 	crc = crc16(crc, (__u8 *)gdp, offset);
2418 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2419 	/* for checksum of struct ext4_group_desc do the rest...*/
2420 	if (ext4_has_feature_64bit(sb) &&
2421 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2422 		crc = crc16(crc, (__u8 *)gdp + offset,
2423 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2424 				offset);
2425 
2426 out:
2427 	return cpu_to_le16(crc);
2428 }
2429 
2430 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2431 				struct ext4_group_desc *gdp)
2432 {
2433 	if (ext4_has_group_desc_csum(sb) &&
2434 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2435 		return 0;
2436 
2437 	return 1;
2438 }
2439 
2440 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2441 			      struct ext4_group_desc *gdp)
2442 {
2443 	if (!ext4_has_group_desc_csum(sb))
2444 		return;
2445 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2446 }
2447 
2448 /* Called at mount-time, super-block is locked */
2449 static int ext4_check_descriptors(struct super_block *sb,
2450 				  ext4_fsblk_t sb_block,
2451 				  ext4_group_t *first_not_zeroed)
2452 {
2453 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2454 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2455 	ext4_fsblk_t last_block;
2456 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2457 	ext4_fsblk_t block_bitmap;
2458 	ext4_fsblk_t inode_bitmap;
2459 	ext4_fsblk_t inode_table;
2460 	int flexbg_flag = 0;
2461 	ext4_group_t i, grp = sbi->s_groups_count;
2462 
2463 	if (ext4_has_feature_flex_bg(sb))
2464 		flexbg_flag = 1;
2465 
2466 	ext4_debug("Checking group descriptors");
2467 
2468 	for (i = 0; i < sbi->s_groups_count; i++) {
2469 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2470 
2471 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2472 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2473 		else
2474 			last_block = first_block +
2475 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2476 
2477 		if ((grp == sbi->s_groups_count) &&
2478 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2479 			grp = i;
2480 
2481 		block_bitmap = ext4_block_bitmap(sb, gdp);
2482 		if (block_bitmap == sb_block) {
2483 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2484 				 "Block bitmap for group %u overlaps "
2485 				 "superblock", i);
2486 			if (!sb_rdonly(sb))
2487 				return 0;
2488 		}
2489 		if (block_bitmap >= sb_block + 1 &&
2490 		    block_bitmap <= last_bg_block) {
2491 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2492 				 "Block bitmap for group %u overlaps "
2493 				 "block group descriptors", i);
2494 			if (!sb_rdonly(sb))
2495 				return 0;
2496 		}
2497 		if (block_bitmap < first_block || block_bitmap > last_block) {
2498 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2499 			       "Block bitmap for group %u not in group "
2500 			       "(block %llu)!", i, block_bitmap);
2501 			return 0;
2502 		}
2503 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2504 		if (inode_bitmap == sb_block) {
2505 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2506 				 "Inode bitmap for group %u overlaps "
2507 				 "superblock", i);
2508 			if (!sb_rdonly(sb))
2509 				return 0;
2510 		}
2511 		if (inode_bitmap >= sb_block + 1 &&
2512 		    inode_bitmap <= last_bg_block) {
2513 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2514 				 "Inode bitmap for group %u overlaps "
2515 				 "block group descriptors", i);
2516 			if (!sb_rdonly(sb))
2517 				return 0;
2518 		}
2519 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2520 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2521 			       "Inode bitmap for group %u not in group "
2522 			       "(block %llu)!", i, inode_bitmap);
2523 			return 0;
2524 		}
2525 		inode_table = ext4_inode_table(sb, gdp);
2526 		if (inode_table == sb_block) {
2527 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2528 				 "Inode table for group %u overlaps "
2529 				 "superblock", i);
2530 			if (!sb_rdonly(sb))
2531 				return 0;
2532 		}
2533 		if (inode_table >= sb_block + 1 &&
2534 		    inode_table <= last_bg_block) {
2535 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2536 				 "Inode table for group %u overlaps "
2537 				 "block group descriptors", i);
2538 			if (!sb_rdonly(sb))
2539 				return 0;
2540 		}
2541 		if (inode_table < first_block ||
2542 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2543 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2544 			       "Inode table for group %u not in group "
2545 			       "(block %llu)!", i, inode_table);
2546 			return 0;
2547 		}
2548 		ext4_lock_group(sb, i);
2549 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2550 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2551 				 "Checksum for group %u failed (%u!=%u)",
2552 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2553 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2554 			if (!sb_rdonly(sb)) {
2555 				ext4_unlock_group(sb, i);
2556 				return 0;
2557 			}
2558 		}
2559 		ext4_unlock_group(sb, i);
2560 		if (!flexbg_flag)
2561 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2562 	}
2563 	if (NULL != first_not_zeroed)
2564 		*first_not_zeroed = grp;
2565 	return 1;
2566 }
2567 
2568 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2569  * the superblock) which were deleted from all directories, but held open by
2570  * a process at the time of a crash.  We walk the list and try to delete these
2571  * inodes at recovery time (only with a read-write filesystem).
2572  *
2573  * In order to keep the orphan inode chain consistent during traversal (in
2574  * case of crash during recovery), we link each inode into the superblock
2575  * orphan list_head and handle it the same way as an inode deletion during
2576  * normal operation (which journals the operations for us).
2577  *
2578  * We only do an iget() and an iput() on each inode, which is very safe if we
2579  * accidentally point at an in-use or already deleted inode.  The worst that
2580  * can happen in this case is that we get a "bit already cleared" message from
2581  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2582  * e2fsck was run on this filesystem, and it must have already done the orphan
2583  * inode cleanup for us, so we can safely abort without any further action.
2584  */
2585 static void ext4_orphan_cleanup(struct super_block *sb,
2586 				struct ext4_super_block *es)
2587 {
2588 	unsigned int s_flags = sb->s_flags;
2589 	int ret, nr_orphans = 0, nr_truncates = 0;
2590 #ifdef CONFIG_QUOTA
2591 	int quota_update = 0;
2592 	int i;
2593 #endif
2594 	if (!es->s_last_orphan) {
2595 		jbd_debug(4, "no orphan inodes to clean up\n");
2596 		return;
2597 	}
2598 
2599 	if (bdev_read_only(sb->s_bdev)) {
2600 		ext4_msg(sb, KERN_ERR, "write access "
2601 			"unavailable, skipping orphan cleanup");
2602 		return;
2603 	}
2604 
2605 	/* Check if feature set would not allow a r/w mount */
2606 	if (!ext4_feature_set_ok(sb, 0)) {
2607 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2608 			 "unknown ROCOMPAT features");
2609 		return;
2610 	}
2611 
2612 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2613 		/* don't clear list on RO mount w/ errors */
2614 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2615 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2616 				  "clearing orphan list.\n");
2617 			es->s_last_orphan = 0;
2618 		}
2619 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2620 		return;
2621 	}
2622 
2623 	if (s_flags & SB_RDONLY) {
2624 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2625 		sb->s_flags &= ~SB_RDONLY;
2626 	}
2627 #ifdef CONFIG_QUOTA
2628 	/* Needed for iput() to work correctly and not trash data */
2629 	sb->s_flags |= SB_ACTIVE;
2630 
2631 	/*
2632 	 * Turn on quotas which were not enabled for read-only mounts if
2633 	 * filesystem has quota feature, so that they are updated correctly.
2634 	 */
2635 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2636 		int ret = ext4_enable_quotas(sb);
2637 
2638 		if (!ret)
2639 			quota_update = 1;
2640 		else
2641 			ext4_msg(sb, KERN_ERR,
2642 				"Cannot turn on quotas: error %d", ret);
2643 	}
2644 
2645 	/* Turn on journaled quotas used for old sytle */
2646 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2647 		if (EXT4_SB(sb)->s_qf_names[i]) {
2648 			int ret = ext4_quota_on_mount(sb, i);
2649 
2650 			if (!ret)
2651 				quota_update = 1;
2652 			else
2653 				ext4_msg(sb, KERN_ERR,
2654 					"Cannot turn on journaled "
2655 					"quota: type %d: error %d", i, ret);
2656 		}
2657 	}
2658 #endif
2659 
2660 	while (es->s_last_orphan) {
2661 		struct inode *inode;
2662 
2663 		/*
2664 		 * We may have encountered an error during cleanup; if
2665 		 * so, skip the rest.
2666 		 */
2667 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2668 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2669 			es->s_last_orphan = 0;
2670 			break;
2671 		}
2672 
2673 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2674 		if (IS_ERR(inode)) {
2675 			es->s_last_orphan = 0;
2676 			break;
2677 		}
2678 
2679 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2680 		dquot_initialize(inode);
2681 		if (inode->i_nlink) {
2682 			if (test_opt(sb, DEBUG))
2683 				ext4_msg(sb, KERN_DEBUG,
2684 					"%s: truncating inode %lu to %lld bytes",
2685 					__func__, inode->i_ino, inode->i_size);
2686 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2687 				  inode->i_ino, inode->i_size);
2688 			inode_lock(inode);
2689 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2690 			ret = ext4_truncate(inode);
2691 			if (ret)
2692 				ext4_std_error(inode->i_sb, ret);
2693 			inode_unlock(inode);
2694 			nr_truncates++;
2695 		} else {
2696 			if (test_opt(sb, DEBUG))
2697 				ext4_msg(sb, KERN_DEBUG,
2698 					"%s: deleting unreferenced inode %lu",
2699 					__func__, inode->i_ino);
2700 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2701 				  inode->i_ino);
2702 			nr_orphans++;
2703 		}
2704 		iput(inode);  /* The delete magic happens here! */
2705 	}
2706 
2707 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2708 
2709 	if (nr_orphans)
2710 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2711 		       PLURAL(nr_orphans));
2712 	if (nr_truncates)
2713 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2714 		       PLURAL(nr_truncates));
2715 #ifdef CONFIG_QUOTA
2716 	/* Turn off quotas if they were enabled for orphan cleanup */
2717 	if (quota_update) {
2718 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2719 			if (sb_dqopt(sb)->files[i])
2720 				dquot_quota_off(sb, i);
2721 		}
2722 	}
2723 #endif
2724 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2725 }
2726 
2727 /*
2728  * Maximal extent format file size.
2729  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2730  * extent format containers, within a sector_t, and within i_blocks
2731  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2732  * so that won't be a limiting factor.
2733  *
2734  * However there is other limiting factor. We do store extents in the form
2735  * of starting block and length, hence the resulting length of the extent
2736  * covering maximum file size must fit into on-disk format containers as
2737  * well. Given that length is always by 1 unit bigger than max unit (because
2738  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2739  *
2740  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2741  */
2742 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2743 {
2744 	loff_t res;
2745 	loff_t upper_limit = MAX_LFS_FILESIZE;
2746 
2747 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2748 
2749 	if (!has_huge_files) {
2750 		upper_limit = (1LL << 32) - 1;
2751 
2752 		/* total blocks in file system block size */
2753 		upper_limit >>= (blkbits - 9);
2754 		upper_limit <<= blkbits;
2755 	}
2756 
2757 	/*
2758 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2759 	 * by one fs block, so ee_len can cover the extent of maximum file
2760 	 * size
2761 	 */
2762 	res = (1LL << 32) - 1;
2763 	res <<= blkbits;
2764 
2765 	/* Sanity check against vm- & vfs- imposed limits */
2766 	if (res > upper_limit)
2767 		res = upper_limit;
2768 
2769 	return res;
2770 }
2771 
2772 /*
2773  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2774  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2775  * We need to be 1 filesystem block less than the 2^48 sector limit.
2776  */
2777 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2778 {
2779 	loff_t res = EXT4_NDIR_BLOCKS;
2780 	int meta_blocks;
2781 	loff_t upper_limit;
2782 	/* This is calculated to be the largest file size for a dense, block
2783 	 * mapped file such that the file's total number of 512-byte sectors,
2784 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2785 	 *
2786 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2787 	 * number of 512-byte sectors of the file.
2788 	 */
2789 
2790 	if (!has_huge_files) {
2791 		/*
2792 		 * !has_huge_files or implies that the inode i_block field
2793 		 * represents total file blocks in 2^32 512-byte sectors ==
2794 		 * size of vfs inode i_blocks * 8
2795 		 */
2796 		upper_limit = (1LL << 32) - 1;
2797 
2798 		/* total blocks in file system block size */
2799 		upper_limit >>= (bits - 9);
2800 
2801 	} else {
2802 		/*
2803 		 * We use 48 bit ext4_inode i_blocks
2804 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2805 		 * represent total number of blocks in
2806 		 * file system block size
2807 		 */
2808 		upper_limit = (1LL << 48) - 1;
2809 
2810 	}
2811 
2812 	/* indirect blocks */
2813 	meta_blocks = 1;
2814 	/* double indirect blocks */
2815 	meta_blocks += 1 + (1LL << (bits-2));
2816 	/* tripple indirect blocks */
2817 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2818 
2819 	upper_limit -= meta_blocks;
2820 	upper_limit <<= bits;
2821 
2822 	res += 1LL << (bits-2);
2823 	res += 1LL << (2*(bits-2));
2824 	res += 1LL << (3*(bits-2));
2825 	res <<= bits;
2826 	if (res > upper_limit)
2827 		res = upper_limit;
2828 
2829 	if (res > MAX_LFS_FILESIZE)
2830 		res = MAX_LFS_FILESIZE;
2831 
2832 	return res;
2833 }
2834 
2835 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2836 				   ext4_fsblk_t logical_sb_block, int nr)
2837 {
2838 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2839 	ext4_group_t bg, first_meta_bg;
2840 	int has_super = 0;
2841 
2842 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2843 
2844 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2845 		return logical_sb_block + nr + 1;
2846 	bg = sbi->s_desc_per_block * nr;
2847 	if (ext4_bg_has_super(sb, bg))
2848 		has_super = 1;
2849 
2850 	/*
2851 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2852 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2853 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2854 	 * compensate.
2855 	 */
2856 	if (sb->s_blocksize == 1024 && nr == 0 &&
2857 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2858 		has_super++;
2859 
2860 	return (has_super + ext4_group_first_block_no(sb, bg));
2861 }
2862 
2863 /**
2864  * ext4_get_stripe_size: Get the stripe size.
2865  * @sbi: In memory super block info
2866  *
2867  * If we have specified it via mount option, then
2868  * use the mount option value. If the value specified at mount time is
2869  * greater than the blocks per group use the super block value.
2870  * If the super block value is greater than blocks per group return 0.
2871  * Allocator needs it be less than blocks per group.
2872  *
2873  */
2874 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2875 {
2876 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2877 	unsigned long stripe_width =
2878 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2879 	int ret;
2880 
2881 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2882 		ret = sbi->s_stripe;
2883 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2884 		ret = stripe_width;
2885 	else if (stride && stride <= sbi->s_blocks_per_group)
2886 		ret = stride;
2887 	else
2888 		ret = 0;
2889 
2890 	/*
2891 	 * If the stripe width is 1, this makes no sense and
2892 	 * we set it to 0 to turn off stripe handling code.
2893 	 */
2894 	if (ret <= 1)
2895 		ret = 0;
2896 
2897 	return ret;
2898 }
2899 
2900 /*
2901  * Check whether this filesystem can be mounted based on
2902  * the features present and the RDONLY/RDWR mount requested.
2903  * Returns 1 if this filesystem can be mounted as requested,
2904  * 0 if it cannot be.
2905  */
2906 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2907 {
2908 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2909 		ext4_msg(sb, KERN_ERR,
2910 			"Couldn't mount because of "
2911 			"unsupported optional features (%x)",
2912 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2913 			~EXT4_FEATURE_INCOMPAT_SUPP));
2914 		return 0;
2915 	}
2916 
2917 #ifndef CONFIG_UNICODE
2918 	if (ext4_has_feature_casefold(sb)) {
2919 		ext4_msg(sb, KERN_ERR,
2920 			 "Filesystem with casefold feature cannot be "
2921 			 "mounted without CONFIG_UNICODE");
2922 		return 0;
2923 	}
2924 #endif
2925 
2926 	if (readonly)
2927 		return 1;
2928 
2929 	if (ext4_has_feature_readonly(sb)) {
2930 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2931 		sb->s_flags |= SB_RDONLY;
2932 		return 1;
2933 	}
2934 
2935 	/* Check that feature set is OK for a read-write mount */
2936 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2937 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2938 			 "unsupported optional features (%x)",
2939 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2940 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2941 		return 0;
2942 	}
2943 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2944 		ext4_msg(sb, KERN_ERR,
2945 			 "Can't support bigalloc feature without "
2946 			 "extents feature\n");
2947 		return 0;
2948 	}
2949 
2950 #ifndef CONFIG_QUOTA
2951 	if (ext4_has_feature_quota(sb) && !readonly) {
2952 		ext4_msg(sb, KERN_ERR,
2953 			 "Filesystem with quota feature cannot be mounted RDWR "
2954 			 "without CONFIG_QUOTA");
2955 		return 0;
2956 	}
2957 	if (ext4_has_feature_project(sb) && !readonly) {
2958 		ext4_msg(sb, KERN_ERR,
2959 			 "Filesystem with project quota feature cannot be mounted RDWR "
2960 			 "without CONFIG_QUOTA");
2961 		return 0;
2962 	}
2963 #endif  /* CONFIG_QUOTA */
2964 	return 1;
2965 }
2966 
2967 /*
2968  * This function is called once a day if we have errors logged
2969  * on the file system
2970  */
2971 static void print_daily_error_info(struct timer_list *t)
2972 {
2973 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2974 	struct super_block *sb = sbi->s_sb;
2975 	struct ext4_super_block *es = sbi->s_es;
2976 
2977 	if (es->s_error_count)
2978 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2979 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2980 			 le32_to_cpu(es->s_error_count));
2981 	if (es->s_first_error_time) {
2982 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2983 		       sb->s_id,
2984 		       ext4_get_tstamp(es, s_first_error_time),
2985 		       (int) sizeof(es->s_first_error_func),
2986 		       es->s_first_error_func,
2987 		       le32_to_cpu(es->s_first_error_line));
2988 		if (es->s_first_error_ino)
2989 			printk(KERN_CONT ": inode %u",
2990 			       le32_to_cpu(es->s_first_error_ino));
2991 		if (es->s_first_error_block)
2992 			printk(KERN_CONT ": block %llu", (unsigned long long)
2993 			       le64_to_cpu(es->s_first_error_block));
2994 		printk(KERN_CONT "\n");
2995 	}
2996 	if (es->s_last_error_time) {
2997 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
2998 		       sb->s_id,
2999 		       ext4_get_tstamp(es, s_last_error_time),
3000 		       (int) sizeof(es->s_last_error_func),
3001 		       es->s_last_error_func,
3002 		       le32_to_cpu(es->s_last_error_line));
3003 		if (es->s_last_error_ino)
3004 			printk(KERN_CONT ": inode %u",
3005 			       le32_to_cpu(es->s_last_error_ino));
3006 		if (es->s_last_error_block)
3007 			printk(KERN_CONT ": block %llu", (unsigned long long)
3008 			       le64_to_cpu(es->s_last_error_block));
3009 		printk(KERN_CONT "\n");
3010 	}
3011 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3012 }
3013 
3014 /* Find next suitable group and run ext4_init_inode_table */
3015 static int ext4_run_li_request(struct ext4_li_request *elr)
3016 {
3017 	struct ext4_group_desc *gdp = NULL;
3018 	ext4_group_t group, ngroups;
3019 	struct super_block *sb;
3020 	unsigned long timeout = 0;
3021 	int ret = 0;
3022 
3023 	sb = elr->lr_super;
3024 	ngroups = EXT4_SB(sb)->s_groups_count;
3025 
3026 	for (group = elr->lr_next_group; group < ngroups; group++) {
3027 		gdp = ext4_get_group_desc(sb, group, NULL);
3028 		if (!gdp) {
3029 			ret = 1;
3030 			break;
3031 		}
3032 
3033 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3034 			break;
3035 	}
3036 
3037 	if (group >= ngroups)
3038 		ret = 1;
3039 
3040 	if (!ret) {
3041 		timeout = jiffies;
3042 		ret = ext4_init_inode_table(sb, group,
3043 					    elr->lr_timeout ? 0 : 1);
3044 		if (elr->lr_timeout == 0) {
3045 			timeout = (jiffies - timeout) *
3046 				  elr->lr_sbi->s_li_wait_mult;
3047 			elr->lr_timeout = timeout;
3048 		}
3049 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3050 		elr->lr_next_group = group + 1;
3051 	}
3052 	return ret;
3053 }
3054 
3055 /*
3056  * Remove lr_request from the list_request and free the
3057  * request structure. Should be called with li_list_mtx held
3058  */
3059 static void ext4_remove_li_request(struct ext4_li_request *elr)
3060 {
3061 	struct ext4_sb_info *sbi;
3062 
3063 	if (!elr)
3064 		return;
3065 
3066 	sbi = elr->lr_sbi;
3067 
3068 	list_del(&elr->lr_request);
3069 	sbi->s_li_request = NULL;
3070 	kfree(elr);
3071 }
3072 
3073 static void ext4_unregister_li_request(struct super_block *sb)
3074 {
3075 	mutex_lock(&ext4_li_mtx);
3076 	if (!ext4_li_info) {
3077 		mutex_unlock(&ext4_li_mtx);
3078 		return;
3079 	}
3080 
3081 	mutex_lock(&ext4_li_info->li_list_mtx);
3082 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3083 	mutex_unlock(&ext4_li_info->li_list_mtx);
3084 	mutex_unlock(&ext4_li_mtx);
3085 }
3086 
3087 static struct task_struct *ext4_lazyinit_task;
3088 
3089 /*
3090  * This is the function where ext4lazyinit thread lives. It walks
3091  * through the request list searching for next scheduled filesystem.
3092  * When such a fs is found, run the lazy initialization request
3093  * (ext4_rn_li_request) and keep track of the time spend in this
3094  * function. Based on that time we compute next schedule time of
3095  * the request. When walking through the list is complete, compute
3096  * next waking time and put itself into sleep.
3097  */
3098 static int ext4_lazyinit_thread(void *arg)
3099 {
3100 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3101 	struct list_head *pos, *n;
3102 	struct ext4_li_request *elr;
3103 	unsigned long next_wakeup, cur;
3104 
3105 	BUG_ON(NULL == eli);
3106 
3107 cont_thread:
3108 	while (true) {
3109 		next_wakeup = MAX_JIFFY_OFFSET;
3110 
3111 		mutex_lock(&eli->li_list_mtx);
3112 		if (list_empty(&eli->li_request_list)) {
3113 			mutex_unlock(&eli->li_list_mtx);
3114 			goto exit_thread;
3115 		}
3116 		list_for_each_safe(pos, n, &eli->li_request_list) {
3117 			int err = 0;
3118 			int progress = 0;
3119 			elr = list_entry(pos, struct ext4_li_request,
3120 					 lr_request);
3121 
3122 			if (time_before(jiffies, elr->lr_next_sched)) {
3123 				if (time_before(elr->lr_next_sched, next_wakeup))
3124 					next_wakeup = elr->lr_next_sched;
3125 				continue;
3126 			}
3127 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3128 				if (sb_start_write_trylock(elr->lr_super)) {
3129 					progress = 1;
3130 					/*
3131 					 * We hold sb->s_umount, sb can not
3132 					 * be removed from the list, it is
3133 					 * now safe to drop li_list_mtx
3134 					 */
3135 					mutex_unlock(&eli->li_list_mtx);
3136 					err = ext4_run_li_request(elr);
3137 					sb_end_write(elr->lr_super);
3138 					mutex_lock(&eli->li_list_mtx);
3139 					n = pos->next;
3140 				}
3141 				up_read((&elr->lr_super->s_umount));
3142 			}
3143 			/* error, remove the lazy_init job */
3144 			if (err) {
3145 				ext4_remove_li_request(elr);
3146 				continue;
3147 			}
3148 			if (!progress) {
3149 				elr->lr_next_sched = jiffies +
3150 					(prandom_u32()
3151 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3152 			}
3153 			if (time_before(elr->lr_next_sched, next_wakeup))
3154 				next_wakeup = elr->lr_next_sched;
3155 		}
3156 		mutex_unlock(&eli->li_list_mtx);
3157 
3158 		try_to_freeze();
3159 
3160 		cur = jiffies;
3161 		if ((time_after_eq(cur, next_wakeup)) ||
3162 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3163 			cond_resched();
3164 			continue;
3165 		}
3166 
3167 		schedule_timeout_interruptible(next_wakeup - cur);
3168 
3169 		if (kthread_should_stop()) {
3170 			ext4_clear_request_list();
3171 			goto exit_thread;
3172 		}
3173 	}
3174 
3175 exit_thread:
3176 	/*
3177 	 * It looks like the request list is empty, but we need
3178 	 * to check it under the li_list_mtx lock, to prevent any
3179 	 * additions into it, and of course we should lock ext4_li_mtx
3180 	 * to atomically free the list and ext4_li_info, because at
3181 	 * this point another ext4 filesystem could be registering
3182 	 * new one.
3183 	 */
3184 	mutex_lock(&ext4_li_mtx);
3185 	mutex_lock(&eli->li_list_mtx);
3186 	if (!list_empty(&eli->li_request_list)) {
3187 		mutex_unlock(&eli->li_list_mtx);
3188 		mutex_unlock(&ext4_li_mtx);
3189 		goto cont_thread;
3190 	}
3191 	mutex_unlock(&eli->li_list_mtx);
3192 	kfree(ext4_li_info);
3193 	ext4_li_info = NULL;
3194 	mutex_unlock(&ext4_li_mtx);
3195 
3196 	return 0;
3197 }
3198 
3199 static void ext4_clear_request_list(void)
3200 {
3201 	struct list_head *pos, *n;
3202 	struct ext4_li_request *elr;
3203 
3204 	mutex_lock(&ext4_li_info->li_list_mtx);
3205 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3206 		elr = list_entry(pos, struct ext4_li_request,
3207 				 lr_request);
3208 		ext4_remove_li_request(elr);
3209 	}
3210 	mutex_unlock(&ext4_li_info->li_list_mtx);
3211 }
3212 
3213 static int ext4_run_lazyinit_thread(void)
3214 {
3215 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3216 					 ext4_li_info, "ext4lazyinit");
3217 	if (IS_ERR(ext4_lazyinit_task)) {
3218 		int err = PTR_ERR(ext4_lazyinit_task);
3219 		ext4_clear_request_list();
3220 		kfree(ext4_li_info);
3221 		ext4_li_info = NULL;
3222 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3223 				 "initialization thread\n",
3224 				 err);
3225 		return err;
3226 	}
3227 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3228 	return 0;
3229 }
3230 
3231 /*
3232  * Check whether it make sense to run itable init. thread or not.
3233  * If there is at least one uninitialized inode table, return
3234  * corresponding group number, else the loop goes through all
3235  * groups and return total number of groups.
3236  */
3237 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3238 {
3239 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3240 	struct ext4_group_desc *gdp = NULL;
3241 
3242 	if (!ext4_has_group_desc_csum(sb))
3243 		return ngroups;
3244 
3245 	for (group = 0; group < ngroups; group++) {
3246 		gdp = ext4_get_group_desc(sb, group, NULL);
3247 		if (!gdp)
3248 			continue;
3249 
3250 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3251 			break;
3252 	}
3253 
3254 	return group;
3255 }
3256 
3257 static int ext4_li_info_new(void)
3258 {
3259 	struct ext4_lazy_init *eli = NULL;
3260 
3261 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3262 	if (!eli)
3263 		return -ENOMEM;
3264 
3265 	INIT_LIST_HEAD(&eli->li_request_list);
3266 	mutex_init(&eli->li_list_mtx);
3267 
3268 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3269 
3270 	ext4_li_info = eli;
3271 
3272 	return 0;
3273 }
3274 
3275 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3276 					    ext4_group_t start)
3277 {
3278 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3279 	struct ext4_li_request *elr;
3280 
3281 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3282 	if (!elr)
3283 		return NULL;
3284 
3285 	elr->lr_super = sb;
3286 	elr->lr_sbi = sbi;
3287 	elr->lr_next_group = start;
3288 
3289 	/*
3290 	 * Randomize first schedule time of the request to
3291 	 * spread the inode table initialization requests
3292 	 * better.
3293 	 */
3294 	elr->lr_next_sched = jiffies + (prandom_u32() %
3295 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3296 	return elr;
3297 }
3298 
3299 int ext4_register_li_request(struct super_block *sb,
3300 			     ext4_group_t first_not_zeroed)
3301 {
3302 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3303 	struct ext4_li_request *elr = NULL;
3304 	ext4_group_t ngroups = sbi->s_groups_count;
3305 	int ret = 0;
3306 
3307 	mutex_lock(&ext4_li_mtx);
3308 	if (sbi->s_li_request != NULL) {
3309 		/*
3310 		 * Reset timeout so it can be computed again, because
3311 		 * s_li_wait_mult might have changed.
3312 		 */
3313 		sbi->s_li_request->lr_timeout = 0;
3314 		goto out;
3315 	}
3316 
3317 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3318 	    !test_opt(sb, INIT_INODE_TABLE))
3319 		goto out;
3320 
3321 	elr = ext4_li_request_new(sb, first_not_zeroed);
3322 	if (!elr) {
3323 		ret = -ENOMEM;
3324 		goto out;
3325 	}
3326 
3327 	if (NULL == ext4_li_info) {
3328 		ret = ext4_li_info_new();
3329 		if (ret)
3330 			goto out;
3331 	}
3332 
3333 	mutex_lock(&ext4_li_info->li_list_mtx);
3334 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3335 	mutex_unlock(&ext4_li_info->li_list_mtx);
3336 
3337 	sbi->s_li_request = elr;
3338 	/*
3339 	 * set elr to NULL here since it has been inserted to
3340 	 * the request_list and the removal and free of it is
3341 	 * handled by ext4_clear_request_list from now on.
3342 	 */
3343 	elr = NULL;
3344 
3345 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3346 		ret = ext4_run_lazyinit_thread();
3347 		if (ret)
3348 			goto out;
3349 	}
3350 out:
3351 	mutex_unlock(&ext4_li_mtx);
3352 	if (ret)
3353 		kfree(elr);
3354 	return ret;
3355 }
3356 
3357 /*
3358  * We do not need to lock anything since this is called on
3359  * module unload.
3360  */
3361 static void ext4_destroy_lazyinit_thread(void)
3362 {
3363 	/*
3364 	 * If thread exited earlier
3365 	 * there's nothing to be done.
3366 	 */
3367 	if (!ext4_li_info || !ext4_lazyinit_task)
3368 		return;
3369 
3370 	kthread_stop(ext4_lazyinit_task);
3371 }
3372 
3373 static int set_journal_csum_feature_set(struct super_block *sb)
3374 {
3375 	int ret = 1;
3376 	int compat, incompat;
3377 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3378 
3379 	if (ext4_has_metadata_csum(sb)) {
3380 		/* journal checksum v3 */
3381 		compat = 0;
3382 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3383 	} else {
3384 		/* journal checksum v1 */
3385 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3386 		incompat = 0;
3387 	}
3388 
3389 	jbd2_journal_clear_features(sbi->s_journal,
3390 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3391 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3392 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3393 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3394 		ret = jbd2_journal_set_features(sbi->s_journal,
3395 				compat, 0,
3396 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3397 				incompat);
3398 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3399 		ret = jbd2_journal_set_features(sbi->s_journal,
3400 				compat, 0,
3401 				incompat);
3402 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3403 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3404 	} else {
3405 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3406 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3407 	}
3408 
3409 	return ret;
3410 }
3411 
3412 /*
3413  * Note: calculating the overhead so we can be compatible with
3414  * historical BSD practice is quite difficult in the face of
3415  * clusters/bigalloc.  This is because multiple metadata blocks from
3416  * different block group can end up in the same allocation cluster.
3417  * Calculating the exact overhead in the face of clustered allocation
3418  * requires either O(all block bitmaps) in memory or O(number of block
3419  * groups**2) in time.  We will still calculate the superblock for
3420  * older file systems --- and if we come across with a bigalloc file
3421  * system with zero in s_overhead_clusters the estimate will be close to
3422  * correct especially for very large cluster sizes --- but for newer
3423  * file systems, it's better to calculate this figure once at mkfs
3424  * time, and store it in the superblock.  If the superblock value is
3425  * present (even for non-bigalloc file systems), we will use it.
3426  */
3427 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3428 			  char *buf)
3429 {
3430 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3431 	struct ext4_group_desc	*gdp;
3432 	ext4_fsblk_t		first_block, last_block, b;
3433 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3434 	int			s, j, count = 0;
3435 
3436 	if (!ext4_has_feature_bigalloc(sb))
3437 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3438 			sbi->s_itb_per_group + 2);
3439 
3440 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3441 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3442 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3443 	for (i = 0; i < ngroups; i++) {
3444 		gdp = ext4_get_group_desc(sb, i, NULL);
3445 		b = ext4_block_bitmap(sb, gdp);
3446 		if (b >= first_block && b <= last_block) {
3447 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3448 			count++;
3449 		}
3450 		b = ext4_inode_bitmap(sb, gdp);
3451 		if (b >= first_block && b <= last_block) {
3452 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3453 			count++;
3454 		}
3455 		b = ext4_inode_table(sb, gdp);
3456 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3457 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3458 				int c = EXT4_B2C(sbi, b - first_block);
3459 				ext4_set_bit(c, buf);
3460 				count++;
3461 			}
3462 		if (i != grp)
3463 			continue;
3464 		s = 0;
3465 		if (ext4_bg_has_super(sb, grp)) {
3466 			ext4_set_bit(s++, buf);
3467 			count++;
3468 		}
3469 		j = ext4_bg_num_gdb(sb, grp);
3470 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3471 			ext4_error(sb, "Invalid number of block group "
3472 				   "descriptor blocks: %d", j);
3473 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3474 		}
3475 		count += j;
3476 		for (; j > 0; j--)
3477 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3478 	}
3479 	if (!count)
3480 		return 0;
3481 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3482 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3483 }
3484 
3485 /*
3486  * Compute the overhead and stash it in sbi->s_overhead
3487  */
3488 int ext4_calculate_overhead(struct super_block *sb)
3489 {
3490 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3491 	struct ext4_super_block *es = sbi->s_es;
3492 	struct inode *j_inode;
3493 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3494 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3495 	ext4_fsblk_t overhead = 0;
3496 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3497 
3498 	if (!buf)
3499 		return -ENOMEM;
3500 
3501 	/*
3502 	 * Compute the overhead (FS structures).  This is constant
3503 	 * for a given filesystem unless the number of block groups
3504 	 * changes so we cache the previous value until it does.
3505 	 */
3506 
3507 	/*
3508 	 * All of the blocks before first_data_block are overhead
3509 	 */
3510 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3511 
3512 	/*
3513 	 * Add the overhead found in each block group
3514 	 */
3515 	for (i = 0; i < ngroups; i++) {
3516 		int blks;
3517 
3518 		blks = count_overhead(sb, i, buf);
3519 		overhead += blks;
3520 		if (blks)
3521 			memset(buf, 0, PAGE_SIZE);
3522 		cond_resched();
3523 	}
3524 
3525 	/*
3526 	 * Add the internal journal blocks whether the journal has been
3527 	 * loaded or not
3528 	 */
3529 	if (sbi->s_journal && !sbi->journal_bdev)
3530 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3531 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3532 		j_inode = ext4_get_journal_inode(sb, j_inum);
3533 		if (j_inode) {
3534 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3535 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3536 			iput(j_inode);
3537 		} else {
3538 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3539 		}
3540 	}
3541 	sbi->s_overhead = overhead;
3542 	smp_wmb();
3543 	free_page((unsigned long) buf);
3544 	return 0;
3545 }
3546 
3547 static void ext4_clamp_want_extra_isize(struct super_block *sb)
3548 {
3549 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3550 	struct ext4_super_block *es = sbi->s_es;
3551 
3552 	/* determine the minimum size of new large inodes, if present */
3553 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
3554 	    sbi->s_want_extra_isize == 0) {
3555 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3556 						     EXT4_GOOD_OLD_INODE_SIZE;
3557 		if (ext4_has_feature_extra_isize(sb)) {
3558 			if (sbi->s_want_extra_isize <
3559 			    le16_to_cpu(es->s_want_extra_isize))
3560 				sbi->s_want_extra_isize =
3561 					le16_to_cpu(es->s_want_extra_isize);
3562 			if (sbi->s_want_extra_isize <
3563 			    le16_to_cpu(es->s_min_extra_isize))
3564 				sbi->s_want_extra_isize =
3565 					le16_to_cpu(es->s_min_extra_isize);
3566 		}
3567 	}
3568 	/* Check if enough inode space is available */
3569 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3570 							sbi->s_inode_size) {
3571 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3572 						       EXT4_GOOD_OLD_INODE_SIZE;
3573 		ext4_msg(sb, KERN_INFO,
3574 			 "required extra inode space not available");
3575 	}
3576 }
3577 
3578 static void ext4_set_resv_clusters(struct super_block *sb)
3579 {
3580 	ext4_fsblk_t resv_clusters;
3581 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3582 
3583 	/*
3584 	 * There's no need to reserve anything when we aren't using extents.
3585 	 * The space estimates are exact, there are no unwritten extents,
3586 	 * hole punching doesn't need new metadata... This is needed especially
3587 	 * to keep ext2/3 backward compatibility.
3588 	 */
3589 	if (!ext4_has_feature_extents(sb))
3590 		return;
3591 	/*
3592 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3593 	 * This should cover the situations where we can not afford to run
3594 	 * out of space like for example punch hole, or converting
3595 	 * unwritten extents in delalloc path. In most cases such
3596 	 * allocation would require 1, or 2 blocks, higher numbers are
3597 	 * very rare.
3598 	 */
3599 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3600 			 sbi->s_cluster_bits);
3601 
3602 	do_div(resv_clusters, 50);
3603 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3604 
3605 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3606 }
3607 
3608 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3609 {
3610 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3611 	char *orig_data = kstrdup(data, GFP_KERNEL);
3612 	struct buffer_head *bh;
3613 	struct ext4_super_block *es = NULL;
3614 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3615 	ext4_fsblk_t block;
3616 	ext4_fsblk_t sb_block = get_sb_block(&data);
3617 	ext4_fsblk_t logical_sb_block;
3618 	unsigned long offset = 0;
3619 	unsigned long journal_devnum = 0;
3620 	unsigned long def_mount_opts;
3621 	struct inode *root;
3622 	const char *descr;
3623 	int ret = -ENOMEM;
3624 	int blocksize, clustersize;
3625 	unsigned int db_count;
3626 	unsigned int i;
3627 	int needs_recovery, has_huge_files, has_bigalloc;
3628 	__u64 blocks_count;
3629 	int err = 0;
3630 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3631 	ext4_group_t first_not_zeroed;
3632 
3633 	if ((data && !orig_data) || !sbi)
3634 		goto out_free_base;
3635 
3636 	sbi->s_daxdev = dax_dev;
3637 	sbi->s_blockgroup_lock =
3638 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3639 	if (!sbi->s_blockgroup_lock)
3640 		goto out_free_base;
3641 
3642 	sb->s_fs_info = sbi;
3643 	sbi->s_sb = sb;
3644 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3645 	sbi->s_sb_block = sb_block;
3646 	if (sb->s_bdev->bd_part)
3647 		sbi->s_sectors_written_start =
3648 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3649 
3650 	/* Cleanup superblock name */
3651 	strreplace(sb->s_id, '/', '!');
3652 
3653 	/* -EINVAL is default */
3654 	ret = -EINVAL;
3655 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3656 	if (!blocksize) {
3657 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3658 		goto out_fail;
3659 	}
3660 
3661 	/*
3662 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3663 	 * block sizes.  We need to calculate the offset from buffer start.
3664 	 */
3665 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3666 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3667 		offset = do_div(logical_sb_block, blocksize);
3668 	} else {
3669 		logical_sb_block = sb_block;
3670 	}
3671 
3672 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3673 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3674 		goto out_fail;
3675 	}
3676 	/*
3677 	 * Note: s_es must be initialized as soon as possible because
3678 	 *       some ext4 macro-instructions depend on its value
3679 	 */
3680 	es = (struct ext4_super_block *) (bh->b_data + offset);
3681 	sbi->s_es = es;
3682 	sb->s_magic = le16_to_cpu(es->s_magic);
3683 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3684 		goto cantfind_ext4;
3685 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3686 
3687 	/* Warn if metadata_csum and gdt_csum are both set. */
3688 	if (ext4_has_feature_metadata_csum(sb) &&
3689 	    ext4_has_feature_gdt_csum(sb))
3690 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3691 			     "redundant flags; please run fsck.");
3692 
3693 	/* Check for a known checksum algorithm */
3694 	if (!ext4_verify_csum_type(sb, es)) {
3695 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3696 			 "unknown checksum algorithm.");
3697 		silent = 1;
3698 		goto cantfind_ext4;
3699 	}
3700 
3701 	/* Load the checksum driver */
3702 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3703 	if (IS_ERR(sbi->s_chksum_driver)) {
3704 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3705 		ret = PTR_ERR(sbi->s_chksum_driver);
3706 		sbi->s_chksum_driver = NULL;
3707 		goto failed_mount;
3708 	}
3709 
3710 	/* Check superblock checksum */
3711 	if (!ext4_superblock_csum_verify(sb, es)) {
3712 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3713 			 "invalid superblock checksum.  Run e2fsck?");
3714 		silent = 1;
3715 		ret = -EFSBADCRC;
3716 		goto cantfind_ext4;
3717 	}
3718 
3719 	/* Precompute checksum seed for all metadata */
3720 	if (ext4_has_feature_csum_seed(sb))
3721 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3722 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3723 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3724 					       sizeof(es->s_uuid));
3725 
3726 	/* Set defaults before we parse the mount options */
3727 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3728 	set_opt(sb, INIT_INODE_TABLE);
3729 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3730 		set_opt(sb, DEBUG);
3731 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3732 		set_opt(sb, GRPID);
3733 	if (def_mount_opts & EXT4_DEFM_UID16)
3734 		set_opt(sb, NO_UID32);
3735 	/* xattr user namespace & acls are now defaulted on */
3736 	set_opt(sb, XATTR_USER);
3737 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3738 	set_opt(sb, POSIX_ACL);
3739 #endif
3740 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3741 	if (ext4_has_metadata_csum(sb))
3742 		set_opt(sb, JOURNAL_CHECKSUM);
3743 
3744 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3745 		set_opt(sb, JOURNAL_DATA);
3746 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3747 		set_opt(sb, ORDERED_DATA);
3748 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3749 		set_opt(sb, WRITEBACK_DATA);
3750 
3751 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3752 		set_opt(sb, ERRORS_PANIC);
3753 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3754 		set_opt(sb, ERRORS_CONT);
3755 	else
3756 		set_opt(sb, ERRORS_RO);
3757 	/* block_validity enabled by default; disable with noblock_validity */
3758 	set_opt(sb, BLOCK_VALIDITY);
3759 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3760 		set_opt(sb, DISCARD);
3761 
3762 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3763 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3764 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3765 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3766 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3767 
3768 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3769 		set_opt(sb, BARRIER);
3770 
3771 	/*
3772 	 * enable delayed allocation by default
3773 	 * Use -o nodelalloc to turn it off
3774 	 */
3775 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3776 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3777 		set_opt(sb, DELALLOC);
3778 
3779 	/*
3780 	 * set default s_li_wait_mult for lazyinit, for the case there is
3781 	 * no mount option specified.
3782 	 */
3783 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3784 
3785 	if (sbi->s_es->s_mount_opts[0]) {
3786 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3787 					      sizeof(sbi->s_es->s_mount_opts),
3788 					      GFP_KERNEL);
3789 		if (!s_mount_opts)
3790 			goto failed_mount;
3791 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3792 				   &journal_ioprio, 0)) {
3793 			ext4_msg(sb, KERN_WARNING,
3794 				 "failed to parse options in superblock: %s",
3795 				 s_mount_opts);
3796 		}
3797 		kfree(s_mount_opts);
3798 	}
3799 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3800 	if (!parse_options((char *) data, sb, &journal_devnum,
3801 			   &journal_ioprio, 0))
3802 		goto failed_mount;
3803 
3804 #ifdef CONFIG_UNICODE
3805 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3806 		const struct ext4_sb_encodings *encoding_info;
3807 		struct unicode_map *encoding;
3808 		__u16 encoding_flags;
3809 
3810 		if (ext4_has_feature_encrypt(sb)) {
3811 			ext4_msg(sb, KERN_ERR,
3812 				 "Can't mount with encoding and encryption");
3813 			goto failed_mount;
3814 		}
3815 
3816 		if (ext4_sb_read_encoding(es, &encoding_info,
3817 					  &encoding_flags)) {
3818 			ext4_msg(sb, KERN_ERR,
3819 				 "Encoding requested by superblock is unknown");
3820 			goto failed_mount;
3821 		}
3822 
3823 		encoding = utf8_load(encoding_info->version);
3824 		if (IS_ERR(encoding)) {
3825 			ext4_msg(sb, KERN_ERR,
3826 				 "can't mount with superblock charset: %s-%s "
3827 				 "not supported by the kernel. flags: 0x%x.",
3828 				 encoding_info->name, encoding_info->version,
3829 				 encoding_flags);
3830 			goto failed_mount;
3831 		}
3832 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3833 			 "%s-%s with flags 0x%hx", encoding_info->name,
3834 			 encoding_info->version?:"\b", encoding_flags);
3835 
3836 		sbi->s_encoding = encoding;
3837 		sbi->s_encoding_flags = encoding_flags;
3838 	}
3839 #endif
3840 
3841 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3842 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3843 			    "with data=journal disables delayed "
3844 			    "allocation and O_DIRECT support!\n");
3845 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3846 			ext4_msg(sb, KERN_ERR, "can't mount with "
3847 				 "both data=journal and delalloc");
3848 			goto failed_mount;
3849 		}
3850 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3851 			ext4_msg(sb, KERN_ERR, "can't mount with "
3852 				 "both data=journal and dioread_nolock");
3853 			goto failed_mount;
3854 		}
3855 		if (test_opt(sb, DAX)) {
3856 			ext4_msg(sb, KERN_ERR, "can't mount with "
3857 				 "both data=journal and dax");
3858 			goto failed_mount;
3859 		}
3860 		if (ext4_has_feature_encrypt(sb)) {
3861 			ext4_msg(sb, KERN_WARNING,
3862 				 "encrypted files will use data=ordered "
3863 				 "instead of data journaling mode");
3864 		}
3865 		if (test_opt(sb, DELALLOC))
3866 			clear_opt(sb, DELALLOC);
3867 	} else {
3868 		sb->s_iflags |= SB_I_CGROUPWB;
3869 	}
3870 
3871 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3872 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3873 
3874 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3875 	    (ext4_has_compat_features(sb) ||
3876 	     ext4_has_ro_compat_features(sb) ||
3877 	     ext4_has_incompat_features(sb)))
3878 		ext4_msg(sb, KERN_WARNING,
3879 		       "feature flags set on rev 0 fs, "
3880 		       "running e2fsck is recommended");
3881 
3882 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3883 		set_opt2(sb, HURD_COMPAT);
3884 		if (ext4_has_feature_64bit(sb)) {
3885 			ext4_msg(sb, KERN_ERR,
3886 				 "The Hurd can't support 64-bit file systems");
3887 			goto failed_mount;
3888 		}
3889 
3890 		/*
3891 		 * ea_inode feature uses l_i_version field which is not
3892 		 * available in HURD_COMPAT mode.
3893 		 */
3894 		if (ext4_has_feature_ea_inode(sb)) {
3895 			ext4_msg(sb, KERN_ERR,
3896 				 "ea_inode feature is not supported for Hurd");
3897 			goto failed_mount;
3898 		}
3899 	}
3900 
3901 	if (IS_EXT2_SB(sb)) {
3902 		if (ext2_feature_set_ok(sb))
3903 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3904 				 "using the ext4 subsystem");
3905 		else {
3906 			/*
3907 			 * If we're probing be silent, if this looks like
3908 			 * it's actually an ext[34] filesystem.
3909 			 */
3910 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3911 				goto failed_mount;
3912 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3913 				 "to feature incompatibilities");
3914 			goto failed_mount;
3915 		}
3916 	}
3917 
3918 	if (IS_EXT3_SB(sb)) {
3919 		if (ext3_feature_set_ok(sb))
3920 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3921 				 "using the ext4 subsystem");
3922 		else {
3923 			/*
3924 			 * If we're probing be silent, if this looks like
3925 			 * it's actually an ext4 filesystem.
3926 			 */
3927 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3928 				goto failed_mount;
3929 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3930 				 "to feature incompatibilities");
3931 			goto failed_mount;
3932 		}
3933 	}
3934 
3935 	/*
3936 	 * Check feature flags regardless of the revision level, since we
3937 	 * previously didn't change the revision level when setting the flags,
3938 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3939 	 */
3940 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3941 		goto failed_mount;
3942 
3943 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3944 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3945 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3946 		ext4_msg(sb, KERN_ERR,
3947 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3948 			 blocksize, le32_to_cpu(es->s_log_block_size));
3949 		goto failed_mount;
3950 	}
3951 	if (le32_to_cpu(es->s_log_block_size) >
3952 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3953 		ext4_msg(sb, KERN_ERR,
3954 			 "Invalid log block size: %u",
3955 			 le32_to_cpu(es->s_log_block_size));
3956 		goto failed_mount;
3957 	}
3958 	if (le32_to_cpu(es->s_log_cluster_size) >
3959 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3960 		ext4_msg(sb, KERN_ERR,
3961 			 "Invalid log cluster size: %u",
3962 			 le32_to_cpu(es->s_log_cluster_size));
3963 		goto failed_mount;
3964 	}
3965 
3966 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3967 		ext4_msg(sb, KERN_ERR,
3968 			 "Number of reserved GDT blocks insanely large: %d",
3969 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3970 		goto failed_mount;
3971 	}
3972 
3973 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3974 		if (ext4_has_feature_inline_data(sb)) {
3975 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3976 					" that may contain inline data");
3977 			goto failed_mount;
3978 		}
3979 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3980 			ext4_msg(sb, KERN_ERR,
3981 				"DAX unsupported by block device.");
3982 			goto failed_mount;
3983 		}
3984 	}
3985 
3986 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3987 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3988 			 es->s_encryption_level);
3989 		goto failed_mount;
3990 	}
3991 
3992 	if (sb->s_blocksize != blocksize) {
3993 		/* Validate the filesystem blocksize */
3994 		if (!sb_set_blocksize(sb, blocksize)) {
3995 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3996 					blocksize);
3997 			goto failed_mount;
3998 		}
3999 
4000 		brelse(bh);
4001 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4002 		offset = do_div(logical_sb_block, blocksize);
4003 		bh = sb_bread_unmovable(sb, logical_sb_block);
4004 		if (!bh) {
4005 			ext4_msg(sb, KERN_ERR,
4006 			       "Can't read superblock on 2nd try");
4007 			goto failed_mount;
4008 		}
4009 		es = (struct ext4_super_block *)(bh->b_data + offset);
4010 		sbi->s_es = es;
4011 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4012 			ext4_msg(sb, KERN_ERR,
4013 			       "Magic mismatch, very weird!");
4014 			goto failed_mount;
4015 		}
4016 	}
4017 
4018 	has_huge_files = ext4_has_feature_huge_file(sb);
4019 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4020 						      has_huge_files);
4021 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4022 
4023 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4024 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4025 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4026 	} else {
4027 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4028 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4029 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4030 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4031 				 sbi->s_first_ino);
4032 			goto failed_mount;
4033 		}
4034 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4035 		    (!is_power_of_2(sbi->s_inode_size)) ||
4036 		    (sbi->s_inode_size > blocksize)) {
4037 			ext4_msg(sb, KERN_ERR,
4038 			       "unsupported inode size: %d",
4039 			       sbi->s_inode_size);
4040 			goto failed_mount;
4041 		}
4042 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
4043 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
4044 	}
4045 
4046 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4047 	if (ext4_has_feature_64bit(sb)) {
4048 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4049 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4050 		    !is_power_of_2(sbi->s_desc_size)) {
4051 			ext4_msg(sb, KERN_ERR,
4052 			       "unsupported descriptor size %lu",
4053 			       sbi->s_desc_size);
4054 			goto failed_mount;
4055 		}
4056 	} else
4057 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4058 
4059 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4060 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4061 
4062 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4063 	if (sbi->s_inodes_per_block == 0)
4064 		goto cantfind_ext4;
4065 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4066 	    sbi->s_inodes_per_group > blocksize * 8) {
4067 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4068 			 sbi->s_blocks_per_group);
4069 		goto failed_mount;
4070 	}
4071 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4072 					sbi->s_inodes_per_block;
4073 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4074 	sbi->s_sbh = bh;
4075 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4076 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4077 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4078 
4079 	for (i = 0; i < 4; i++)
4080 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4081 	sbi->s_def_hash_version = es->s_def_hash_version;
4082 	if (ext4_has_feature_dir_index(sb)) {
4083 		i = le32_to_cpu(es->s_flags);
4084 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4085 			sbi->s_hash_unsigned = 3;
4086 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4087 #ifdef __CHAR_UNSIGNED__
4088 			if (!sb_rdonly(sb))
4089 				es->s_flags |=
4090 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4091 			sbi->s_hash_unsigned = 3;
4092 #else
4093 			if (!sb_rdonly(sb))
4094 				es->s_flags |=
4095 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4096 #endif
4097 		}
4098 	}
4099 
4100 	/* Handle clustersize */
4101 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4102 	has_bigalloc = ext4_has_feature_bigalloc(sb);
4103 	if (has_bigalloc) {
4104 		if (clustersize < blocksize) {
4105 			ext4_msg(sb, KERN_ERR,
4106 				 "cluster size (%d) smaller than "
4107 				 "block size (%d)", clustersize, blocksize);
4108 			goto failed_mount;
4109 		}
4110 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4111 			le32_to_cpu(es->s_log_block_size);
4112 		sbi->s_clusters_per_group =
4113 			le32_to_cpu(es->s_clusters_per_group);
4114 		if (sbi->s_clusters_per_group > blocksize * 8) {
4115 			ext4_msg(sb, KERN_ERR,
4116 				 "#clusters per group too big: %lu",
4117 				 sbi->s_clusters_per_group);
4118 			goto failed_mount;
4119 		}
4120 		if (sbi->s_blocks_per_group !=
4121 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4122 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4123 				 "clusters per group (%lu) inconsistent",
4124 				 sbi->s_blocks_per_group,
4125 				 sbi->s_clusters_per_group);
4126 			goto failed_mount;
4127 		}
4128 	} else {
4129 		if (clustersize != blocksize) {
4130 			ext4_msg(sb, KERN_ERR,
4131 				 "fragment/cluster size (%d) != "
4132 				 "block size (%d)", clustersize, blocksize);
4133 			goto failed_mount;
4134 		}
4135 		if (sbi->s_blocks_per_group > blocksize * 8) {
4136 			ext4_msg(sb, KERN_ERR,
4137 				 "#blocks per group too big: %lu",
4138 				 sbi->s_blocks_per_group);
4139 			goto failed_mount;
4140 		}
4141 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4142 		sbi->s_cluster_bits = 0;
4143 	}
4144 	sbi->s_cluster_ratio = clustersize / blocksize;
4145 
4146 	/* Do we have standard group size of clustersize * 8 blocks ? */
4147 	if (sbi->s_blocks_per_group == clustersize << 3)
4148 		set_opt2(sb, STD_GROUP_SIZE);
4149 
4150 	/*
4151 	 * Test whether we have more sectors than will fit in sector_t,
4152 	 * and whether the max offset is addressable by the page cache.
4153 	 */
4154 	err = generic_check_addressable(sb->s_blocksize_bits,
4155 					ext4_blocks_count(es));
4156 	if (err) {
4157 		ext4_msg(sb, KERN_ERR, "filesystem"
4158 			 " too large to mount safely on this system");
4159 		goto failed_mount;
4160 	}
4161 
4162 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4163 		goto cantfind_ext4;
4164 
4165 	/* check blocks count against device size */
4166 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4167 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4168 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4169 		       "exceeds size of device (%llu blocks)",
4170 		       ext4_blocks_count(es), blocks_count);
4171 		goto failed_mount;
4172 	}
4173 
4174 	/*
4175 	 * It makes no sense for the first data block to be beyond the end
4176 	 * of the filesystem.
4177 	 */
4178 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4179 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4180 			 "block %u is beyond end of filesystem (%llu)",
4181 			 le32_to_cpu(es->s_first_data_block),
4182 			 ext4_blocks_count(es));
4183 		goto failed_mount;
4184 	}
4185 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4186 	    (sbi->s_cluster_ratio == 1)) {
4187 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4188 			 "block is 0 with a 1k block and cluster size");
4189 		goto failed_mount;
4190 	}
4191 
4192 	blocks_count = (ext4_blocks_count(es) -
4193 			le32_to_cpu(es->s_first_data_block) +
4194 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4195 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4196 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4197 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4198 		       "(block count %llu, first data block %u, "
4199 		       "blocks per group %lu)", sbi->s_groups_count,
4200 		       ext4_blocks_count(es),
4201 		       le32_to_cpu(es->s_first_data_block),
4202 		       EXT4_BLOCKS_PER_GROUP(sb));
4203 		goto failed_mount;
4204 	}
4205 	sbi->s_groups_count = blocks_count;
4206 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4207 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4208 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4209 	    le32_to_cpu(es->s_inodes_count)) {
4210 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4211 			 le32_to_cpu(es->s_inodes_count),
4212 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4213 		ret = -EINVAL;
4214 		goto failed_mount;
4215 	}
4216 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4217 		   EXT4_DESC_PER_BLOCK(sb);
4218 	if (ext4_has_feature_meta_bg(sb)) {
4219 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4220 			ext4_msg(sb, KERN_WARNING,
4221 				 "first meta block group too large: %u "
4222 				 "(group descriptor block count %u)",
4223 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4224 			goto failed_mount;
4225 		}
4226 	}
4227 	sbi->s_group_desc = kvmalloc_array(db_count,
4228 					   sizeof(struct buffer_head *),
4229 					   GFP_KERNEL);
4230 	if (sbi->s_group_desc == NULL) {
4231 		ext4_msg(sb, KERN_ERR, "not enough memory");
4232 		ret = -ENOMEM;
4233 		goto failed_mount;
4234 	}
4235 
4236 	bgl_lock_init(sbi->s_blockgroup_lock);
4237 
4238 	/* Pre-read the descriptors into the buffer cache */
4239 	for (i = 0; i < db_count; i++) {
4240 		block = descriptor_loc(sb, logical_sb_block, i);
4241 		sb_breadahead(sb, block);
4242 	}
4243 
4244 	for (i = 0; i < db_count; i++) {
4245 		block = descriptor_loc(sb, logical_sb_block, i);
4246 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4247 		if (!sbi->s_group_desc[i]) {
4248 			ext4_msg(sb, KERN_ERR,
4249 			       "can't read group descriptor %d", i);
4250 			db_count = i;
4251 			goto failed_mount2;
4252 		}
4253 	}
4254 	sbi->s_gdb_count = db_count;
4255 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4256 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4257 		ret = -EFSCORRUPTED;
4258 		goto failed_mount2;
4259 	}
4260 
4261 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4262 
4263 	/* Register extent status tree shrinker */
4264 	if (ext4_es_register_shrinker(sbi))
4265 		goto failed_mount3;
4266 
4267 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4268 	sbi->s_extent_max_zeroout_kb = 32;
4269 
4270 	/*
4271 	 * set up enough so that it can read an inode
4272 	 */
4273 	sb->s_op = &ext4_sops;
4274 	sb->s_export_op = &ext4_export_ops;
4275 	sb->s_xattr = ext4_xattr_handlers;
4276 #ifdef CONFIG_FS_ENCRYPTION
4277 	sb->s_cop = &ext4_cryptops;
4278 #endif
4279 #ifdef CONFIG_FS_VERITY
4280 	sb->s_vop = &ext4_verityops;
4281 #endif
4282 #ifdef CONFIG_QUOTA
4283 	sb->dq_op = &ext4_quota_operations;
4284 	if (ext4_has_feature_quota(sb))
4285 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4286 	else
4287 		sb->s_qcop = &ext4_qctl_operations;
4288 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4289 #endif
4290 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4291 
4292 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4293 	mutex_init(&sbi->s_orphan_lock);
4294 
4295 	sb->s_root = NULL;
4296 
4297 	needs_recovery = (es->s_last_orphan != 0 ||
4298 			  ext4_has_feature_journal_needs_recovery(sb));
4299 
4300 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4301 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4302 			goto failed_mount3a;
4303 
4304 	/*
4305 	 * The first inode we look at is the journal inode.  Don't try
4306 	 * root first: it may be modified in the journal!
4307 	 */
4308 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4309 		err = ext4_load_journal(sb, es, journal_devnum);
4310 		if (err)
4311 			goto failed_mount3a;
4312 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4313 		   ext4_has_feature_journal_needs_recovery(sb)) {
4314 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4315 		       "suppressed and not mounted read-only");
4316 		goto failed_mount_wq;
4317 	} else {
4318 		/* Nojournal mode, all journal mount options are illegal */
4319 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4320 			ext4_msg(sb, KERN_ERR, "can't mount with "
4321 				 "journal_checksum, fs mounted w/o journal");
4322 			goto failed_mount_wq;
4323 		}
4324 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4325 			ext4_msg(sb, KERN_ERR, "can't mount with "
4326 				 "journal_async_commit, fs mounted w/o journal");
4327 			goto failed_mount_wq;
4328 		}
4329 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4330 			ext4_msg(sb, KERN_ERR, "can't mount with "
4331 				 "commit=%lu, fs mounted w/o journal",
4332 				 sbi->s_commit_interval / HZ);
4333 			goto failed_mount_wq;
4334 		}
4335 		if (EXT4_MOUNT_DATA_FLAGS &
4336 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4337 			ext4_msg(sb, KERN_ERR, "can't mount with "
4338 				 "data=, fs mounted w/o journal");
4339 			goto failed_mount_wq;
4340 		}
4341 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4342 		clear_opt(sb, JOURNAL_CHECKSUM);
4343 		clear_opt(sb, DATA_FLAGS);
4344 		sbi->s_journal = NULL;
4345 		needs_recovery = 0;
4346 		goto no_journal;
4347 	}
4348 
4349 	if (ext4_has_feature_64bit(sb) &&
4350 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4351 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4352 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4353 		goto failed_mount_wq;
4354 	}
4355 
4356 	if (!set_journal_csum_feature_set(sb)) {
4357 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4358 			 "feature set");
4359 		goto failed_mount_wq;
4360 	}
4361 
4362 	/* We have now updated the journal if required, so we can
4363 	 * validate the data journaling mode. */
4364 	switch (test_opt(sb, DATA_FLAGS)) {
4365 	case 0:
4366 		/* No mode set, assume a default based on the journal
4367 		 * capabilities: ORDERED_DATA if the journal can
4368 		 * cope, else JOURNAL_DATA
4369 		 */
4370 		if (jbd2_journal_check_available_features
4371 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4372 			set_opt(sb, ORDERED_DATA);
4373 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4374 		} else {
4375 			set_opt(sb, JOURNAL_DATA);
4376 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4377 		}
4378 		break;
4379 
4380 	case EXT4_MOUNT_ORDERED_DATA:
4381 	case EXT4_MOUNT_WRITEBACK_DATA:
4382 		if (!jbd2_journal_check_available_features
4383 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4384 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4385 			       "requested data journaling mode");
4386 			goto failed_mount_wq;
4387 		}
4388 	default:
4389 		break;
4390 	}
4391 
4392 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4393 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4394 		ext4_msg(sb, KERN_ERR, "can't mount with "
4395 			"journal_async_commit in data=ordered mode");
4396 		goto failed_mount_wq;
4397 	}
4398 
4399 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4400 
4401 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4402 
4403 no_journal:
4404 	if (!test_opt(sb, NO_MBCACHE)) {
4405 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4406 		if (!sbi->s_ea_block_cache) {
4407 			ext4_msg(sb, KERN_ERR,
4408 				 "Failed to create ea_block_cache");
4409 			goto failed_mount_wq;
4410 		}
4411 
4412 		if (ext4_has_feature_ea_inode(sb)) {
4413 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4414 			if (!sbi->s_ea_inode_cache) {
4415 				ext4_msg(sb, KERN_ERR,
4416 					 "Failed to create ea_inode_cache");
4417 				goto failed_mount_wq;
4418 			}
4419 		}
4420 	}
4421 
4422 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4423 	    (blocksize != PAGE_SIZE)) {
4424 		ext4_msg(sb, KERN_ERR,
4425 			 "Unsupported blocksize for fs encryption");
4426 		goto failed_mount_wq;
4427 	}
4428 
4429 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4430 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4431 		goto failed_mount_wq;
4432 	}
4433 
4434 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4435 	    !ext4_has_feature_encrypt(sb)) {
4436 		ext4_set_feature_encrypt(sb);
4437 		ext4_commit_super(sb, 1);
4438 	}
4439 
4440 	/*
4441 	 * Get the # of file system overhead blocks from the
4442 	 * superblock if present.
4443 	 */
4444 	if (es->s_overhead_clusters)
4445 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4446 	else {
4447 		err = ext4_calculate_overhead(sb);
4448 		if (err)
4449 			goto failed_mount_wq;
4450 	}
4451 
4452 	/*
4453 	 * The maximum number of concurrent works can be high and
4454 	 * concurrency isn't really necessary.  Limit it to 1.
4455 	 */
4456 	EXT4_SB(sb)->rsv_conversion_wq =
4457 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4458 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4459 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4460 		ret = -ENOMEM;
4461 		goto failed_mount4;
4462 	}
4463 
4464 	/*
4465 	 * The jbd2_journal_load will have done any necessary log recovery,
4466 	 * so we can safely mount the rest of the filesystem now.
4467 	 */
4468 
4469 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4470 	if (IS_ERR(root)) {
4471 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4472 		ret = PTR_ERR(root);
4473 		root = NULL;
4474 		goto failed_mount4;
4475 	}
4476 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4477 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4478 		iput(root);
4479 		goto failed_mount4;
4480 	}
4481 
4482 #ifdef CONFIG_UNICODE
4483 	if (sbi->s_encoding)
4484 		sb->s_d_op = &ext4_dentry_ops;
4485 #endif
4486 
4487 	sb->s_root = d_make_root(root);
4488 	if (!sb->s_root) {
4489 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4490 		ret = -ENOMEM;
4491 		goto failed_mount4;
4492 	}
4493 
4494 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4495 	if (ret == -EROFS) {
4496 		sb->s_flags |= SB_RDONLY;
4497 		ret = 0;
4498 	} else if (ret)
4499 		goto failed_mount4a;
4500 
4501 	ext4_clamp_want_extra_isize(sb);
4502 
4503 	ext4_set_resv_clusters(sb);
4504 
4505 	err = ext4_setup_system_zone(sb);
4506 	if (err) {
4507 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4508 			 "zone (%d)", err);
4509 		goto failed_mount4a;
4510 	}
4511 
4512 	ext4_ext_init(sb);
4513 	err = ext4_mb_init(sb);
4514 	if (err) {
4515 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4516 			 err);
4517 		goto failed_mount5;
4518 	}
4519 
4520 	block = ext4_count_free_clusters(sb);
4521 	ext4_free_blocks_count_set(sbi->s_es,
4522 				   EXT4_C2B(sbi, block));
4523 	ext4_superblock_csum_set(sb);
4524 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4525 				  GFP_KERNEL);
4526 	if (!err) {
4527 		unsigned long freei = ext4_count_free_inodes(sb);
4528 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4529 		ext4_superblock_csum_set(sb);
4530 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4531 					  GFP_KERNEL);
4532 	}
4533 	if (!err)
4534 		err = percpu_counter_init(&sbi->s_dirs_counter,
4535 					  ext4_count_dirs(sb), GFP_KERNEL);
4536 	if (!err)
4537 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4538 					  GFP_KERNEL);
4539 	if (!err)
4540 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4541 
4542 	if (err) {
4543 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4544 		goto failed_mount6;
4545 	}
4546 
4547 	if (ext4_has_feature_flex_bg(sb))
4548 		if (!ext4_fill_flex_info(sb)) {
4549 			ext4_msg(sb, KERN_ERR,
4550 			       "unable to initialize "
4551 			       "flex_bg meta info!");
4552 			goto failed_mount6;
4553 		}
4554 
4555 	err = ext4_register_li_request(sb, first_not_zeroed);
4556 	if (err)
4557 		goto failed_mount6;
4558 
4559 	err = ext4_register_sysfs(sb);
4560 	if (err)
4561 		goto failed_mount7;
4562 
4563 #ifdef CONFIG_QUOTA
4564 	/* Enable quota usage during mount. */
4565 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4566 		err = ext4_enable_quotas(sb);
4567 		if (err)
4568 			goto failed_mount8;
4569 	}
4570 #endif  /* CONFIG_QUOTA */
4571 
4572 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4573 	ext4_orphan_cleanup(sb, es);
4574 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4575 	if (needs_recovery) {
4576 		ext4_msg(sb, KERN_INFO, "recovery complete");
4577 		ext4_mark_recovery_complete(sb, es);
4578 	}
4579 	if (EXT4_SB(sb)->s_journal) {
4580 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4581 			descr = " journalled data mode";
4582 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4583 			descr = " ordered data mode";
4584 		else
4585 			descr = " writeback data mode";
4586 	} else
4587 		descr = "out journal";
4588 
4589 	if (test_opt(sb, DISCARD)) {
4590 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4591 		if (!blk_queue_discard(q))
4592 			ext4_msg(sb, KERN_WARNING,
4593 				 "mounting with \"discard\" option, but "
4594 				 "the device does not support discard");
4595 	}
4596 
4597 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4598 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4599 			 "Opts: %.*s%s%s", descr,
4600 			 (int) sizeof(sbi->s_es->s_mount_opts),
4601 			 sbi->s_es->s_mount_opts,
4602 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4603 
4604 	if (es->s_error_count)
4605 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4606 
4607 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4608 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4609 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4610 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4611 
4612 	kfree(orig_data);
4613 	return 0;
4614 
4615 cantfind_ext4:
4616 	if (!silent)
4617 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4618 	goto failed_mount;
4619 
4620 #ifdef CONFIG_QUOTA
4621 failed_mount8:
4622 	ext4_unregister_sysfs(sb);
4623 #endif
4624 failed_mount7:
4625 	ext4_unregister_li_request(sb);
4626 failed_mount6:
4627 	ext4_mb_release(sb);
4628 	if (sbi->s_flex_groups)
4629 		kvfree(sbi->s_flex_groups);
4630 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4631 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4632 	percpu_counter_destroy(&sbi->s_dirs_counter);
4633 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4634 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4635 failed_mount5:
4636 	ext4_ext_release(sb);
4637 	ext4_release_system_zone(sb);
4638 failed_mount4a:
4639 	dput(sb->s_root);
4640 	sb->s_root = NULL;
4641 failed_mount4:
4642 	ext4_msg(sb, KERN_ERR, "mount failed");
4643 	if (EXT4_SB(sb)->rsv_conversion_wq)
4644 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4645 failed_mount_wq:
4646 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4647 	sbi->s_ea_inode_cache = NULL;
4648 
4649 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4650 	sbi->s_ea_block_cache = NULL;
4651 
4652 	if (sbi->s_journal) {
4653 		jbd2_journal_destroy(sbi->s_journal);
4654 		sbi->s_journal = NULL;
4655 	}
4656 failed_mount3a:
4657 	ext4_es_unregister_shrinker(sbi);
4658 failed_mount3:
4659 	del_timer_sync(&sbi->s_err_report);
4660 	if (sbi->s_mmp_tsk)
4661 		kthread_stop(sbi->s_mmp_tsk);
4662 failed_mount2:
4663 	for (i = 0; i < db_count; i++)
4664 		brelse(sbi->s_group_desc[i]);
4665 	kvfree(sbi->s_group_desc);
4666 failed_mount:
4667 	if (sbi->s_chksum_driver)
4668 		crypto_free_shash(sbi->s_chksum_driver);
4669 
4670 #ifdef CONFIG_UNICODE
4671 	utf8_unload(sbi->s_encoding);
4672 #endif
4673 
4674 #ifdef CONFIG_QUOTA
4675 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4676 		kfree(get_qf_name(sb, sbi, i));
4677 #endif
4678 	ext4_blkdev_remove(sbi);
4679 	brelse(bh);
4680 out_fail:
4681 	sb->s_fs_info = NULL;
4682 	kfree(sbi->s_blockgroup_lock);
4683 out_free_base:
4684 	kfree(sbi);
4685 	kfree(orig_data);
4686 	fs_put_dax(dax_dev);
4687 	return err ? err : ret;
4688 }
4689 
4690 /*
4691  * Setup any per-fs journal parameters now.  We'll do this both on
4692  * initial mount, once the journal has been initialised but before we've
4693  * done any recovery; and again on any subsequent remount.
4694  */
4695 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4696 {
4697 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4698 
4699 	journal->j_commit_interval = sbi->s_commit_interval;
4700 	journal->j_min_batch_time = sbi->s_min_batch_time;
4701 	journal->j_max_batch_time = sbi->s_max_batch_time;
4702 
4703 	write_lock(&journal->j_state_lock);
4704 	if (test_opt(sb, BARRIER))
4705 		journal->j_flags |= JBD2_BARRIER;
4706 	else
4707 		journal->j_flags &= ~JBD2_BARRIER;
4708 	if (test_opt(sb, DATA_ERR_ABORT))
4709 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4710 	else
4711 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4712 	write_unlock(&journal->j_state_lock);
4713 }
4714 
4715 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4716 					     unsigned int journal_inum)
4717 {
4718 	struct inode *journal_inode;
4719 
4720 	/*
4721 	 * Test for the existence of a valid inode on disk.  Bad things
4722 	 * happen if we iget() an unused inode, as the subsequent iput()
4723 	 * will try to delete it.
4724 	 */
4725 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4726 	if (IS_ERR(journal_inode)) {
4727 		ext4_msg(sb, KERN_ERR, "no journal found");
4728 		return NULL;
4729 	}
4730 	if (!journal_inode->i_nlink) {
4731 		make_bad_inode(journal_inode);
4732 		iput(journal_inode);
4733 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4734 		return NULL;
4735 	}
4736 
4737 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4738 		  journal_inode, journal_inode->i_size);
4739 	if (!S_ISREG(journal_inode->i_mode)) {
4740 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4741 		iput(journal_inode);
4742 		return NULL;
4743 	}
4744 	return journal_inode;
4745 }
4746 
4747 static journal_t *ext4_get_journal(struct super_block *sb,
4748 				   unsigned int journal_inum)
4749 {
4750 	struct inode *journal_inode;
4751 	journal_t *journal;
4752 
4753 	BUG_ON(!ext4_has_feature_journal(sb));
4754 
4755 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4756 	if (!journal_inode)
4757 		return NULL;
4758 
4759 	journal = jbd2_journal_init_inode(journal_inode);
4760 	if (!journal) {
4761 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4762 		iput(journal_inode);
4763 		return NULL;
4764 	}
4765 	journal->j_private = sb;
4766 	ext4_init_journal_params(sb, journal);
4767 	return journal;
4768 }
4769 
4770 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4771 				       dev_t j_dev)
4772 {
4773 	struct buffer_head *bh;
4774 	journal_t *journal;
4775 	ext4_fsblk_t start;
4776 	ext4_fsblk_t len;
4777 	int hblock, blocksize;
4778 	ext4_fsblk_t sb_block;
4779 	unsigned long offset;
4780 	struct ext4_super_block *es;
4781 	struct block_device *bdev;
4782 
4783 	BUG_ON(!ext4_has_feature_journal(sb));
4784 
4785 	bdev = ext4_blkdev_get(j_dev, sb);
4786 	if (bdev == NULL)
4787 		return NULL;
4788 
4789 	blocksize = sb->s_blocksize;
4790 	hblock = bdev_logical_block_size(bdev);
4791 	if (blocksize < hblock) {
4792 		ext4_msg(sb, KERN_ERR,
4793 			"blocksize too small for journal device");
4794 		goto out_bdev;
4795 	}
4796 
4797 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4798 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4799 	set_blocksize(bdev, blocksize);
4800 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4801 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4802 		       "external journal");
4803 		goto out_bdev;
4804 	}
4805 
4806 	es = (struct ext4_super_block *) (bh->b_data + offset);
4807 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4808 	    !(le32_to_cpu(es->s_feature_incompat) &
4809 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4810 		ext4_msg(sb, KERN_ERR, "external journal has "
4811 					"bad superblock");
4812 		brelse(bh);
4813 		goto out_bdev;
4814 	}
4815 
4816 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4817 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4818 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4819 		ext4_msg(sb, KERN_ERR, "external journal has "
4820 				       "corrupt superblock");
4821 		brelse(bh);
4822 		goto out_bdev;
4823 	}
4824 
4825 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4826 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4827 		brelse(bh);
4828 		goto out_bdev;
4829 	}
4830 
4831 	len = ext4_blocks_count(es);
4832 	start = sb_block + 1;
4833 	brelse(bh);	/* we're done with the superblock */
4834 
4835 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4836 					start, len, blocksize);
4837 	if (!journal) {
4838 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4839 		goto out_bdev;
4840 	}
4841 	journal->j_private = sb;
4842 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4843 	wait_on_buffer(journal->j_sb_buffer);
4844 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4845 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4846 		goto out_journal;
4847 	}
4848 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4849 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4850 					"user (unsupported) - %d",
4851 			be32_to_cpu(journal->j_superblock->s_nr_users));
4852 		goto out_journal;
4853 	}
4854 	EXT4_SB(sb)->journal_bdev = bdev;
4855 	ext4_init_journal_params(sb, journal);
4856 	return journal;
4857 
4858 out_journal:
4859 	jbd2_journal_destroy(journal);
4860 out_bdev:
4861 	ext4_blkdev_put(bdev);
4862 	return NULL;
4863 }
4864 
4865 static int ext4_load_journal(struct super_block *sb,
4866 			     struct ext4_super_block *es,
4867 			     unsigned long journal_devnum)
4868 {
4869 	journal_t *journal;
4870 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4871 	dev_t journal_dev;
4872 	int err = 0;
4873 	int really_read_only;
4874 
4875 	BUG_ON(!ext4_has_feature_journal(sb));
4876 
4877 	if (journal_devnum &&
4878 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4879 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4880 			"numbers have changed");
4881 		journal_dev = new_decode_dev(journal_devnum);
4882 	} else
4883 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4884 
4885 	really_read_only = bdev_read_only(sb->s_bdev);
4886 
4887 	/*
4888 	 * Are we loading a blank journal or performing recovery after a
4889 	 * crash?  For recovery, we need to check in advance whether we
4890 	 * can get read-write access to the device.
4891 	 */
4892 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4893 		if (sb_rdonly(sb)) {
4894 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4895 					"required on readonly filesystem");
4896 			if (really_read_only) {
4897 				ext4_msg(sb, KERN_ERR, "write access "
4898 					"unavailable, cannot proceed "
4899 					"(try mounting with noload)");
4900 				return -EROFS;
4901 			}
4902 			ext4_msg(sb, KERN_INFO, "write access will "
4903 			       "be enabled during recovery");
4904 		}
4905 	}
4906 
4907 	if (journal_inum && journal_dev) {
4908 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4909 		       "and inode journals!");
4910 		return -EINVAL;
4911 	}
4912 
4913 	if (journal_inum) {
4914 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4915 			return -EINVAL;
4916 	} else {
4917 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4918 			return -EINVAL;
4919 	}
4920 
4921 	if (!(journal->j_flags & JBD2_BARRIER))
4922 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4923 
4924 	if (!ext4_has_feature_journal_needs_recovery(sb))
4925 		err = jbd2_journal_wipe(journal, !really_read_only);
4926 	if (!err) {
4927 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4928 		if (save)
4929 			memcpy(save, ((char *) es) +
4930 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4931 		err = jbd2_journal_load(journal);
4932 		if (save)
4933 			memcpy(((char *) es) + EXT4_S_ERR_START,
4934 			       save, EXT4_S_ERR_LEN);
4935 		kfree(save);
4936 	}
4937 
4938 	if (err) {
4939 		ext4_msg(sb, KERN_ERR, "error loading journal");
4940 		jbd2_journal_destroy(journal);
4941 		return err;
4942 	}
4943 
4944 	EXT4_SB(sb)->s_journal = journal;
4945 	ext4_clear_journal_err(sb, es);
4946 
4947 	if (!really_read_only && journal_devnum &&
4948 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4949 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4950 
4951 		/* Make sure we flush the recovery flag to disk. */
4952 		ext4_commit_super(sb, 1);
4953 	}
4954 
4955 	return 0;
4956 }
4957 
4958 static int ext4_commit_super(struct super_block *sb, int sync)
4959 {
4960 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4961 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4962 	int error = 0;
4963 
4964 	if (!sbh || block_device_ejected(sb))
4965 		return error;
4966 
4967 	/*
4968 	 * The superblock bh should be mapped, but it might not be if the
4969 	 * device was hot-removed. Not much we can do but fail the I/O.
4970 	 */
4971 	if (!buffer_mapped(sbh))
4972 		return error;
4973 
4974 	/*
4975 	 * If the file system is mounted read-only, don't update the
4976 	 * superblock write time.  This avoids updating the superblock
4977 	 * write time when we are mounting the root file system
4978 	 * read/only but we need to replay the journal; at that point,
4979 	 * for people who are east of GMT and who make their clock
4980 	 * tick in localtime for Windows bug-for-bug compatibility,
4981 	 * the clock is set in the future, and this will cause e2fsck
4982 	 * to complain and force a full file system check.
4983 	 */
4984 	if (!(sb->s_flags & SB_RDONLY))
4985 		ext4_update_tstamp(es, s_wtime);
4986 	if (sb->s_bdev->bd_part)
4987 		es->s_kbytes_written =
4988 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4989 			    ((part_stat_read(sb->s_bdev->bd_part,
4990 					     sectors[STAT_WRITE]) -
4991 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4992 	else
4993 		es->s_kbytes_written =
4994 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4995 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4996 		ext4_free_blocks_count_set(es,
4997 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4998 				&EXT4_SB(sb)->s_freeclusters_counter)));
4999 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5000 		es->s_free_inodes_count =
5001 			cpu_to_le32(percpu_counter_sum_positive(
5002 				&EXT4_SB(sb)->s_freeinodes_counter));
5003 	BUFFER_TRACE(sbh, "marking dirty");
5004 	ext4_superblock_csum_set(sb);
5005 	if (sync)
5006 		lock_buffer(sbh);
5007 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5008 		/*
5009 		 * Oh, dear.  A previous attempt to write the
5010 		 * superblock failed.  This could happen because the
5011 		 * USB device was yanked out.  Or it could happen to
5012 		 * be a transient write error and maybe the block will
5013 		 * be remapped.  Nothing we can do but to retry the
5014 		 * write and hope for the best.
5015 		 */
5016 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5017 		       "superblock detected");
5018 		clear_buffer_write_io_error(sbh);
5019 		set_buffer_uptodate(sbh);
5020 	}
5021 	mark_buffer_dirty(sbh);
5022 	if (sync) {
5023 		unlock_buffer(sbh);
5024 		error = __sync_dirty_buffer(sbh,
5025 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5026 		if (buffer_write_io_error(sbh)) {
5027 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5028 			       "superblock");
5029 			clear_buffer_write_io_error(sbh);
5030 			set_buffer_uptodate(sbh);
5031 		}
5032 	}
5033 	return error;
5034 }
5035 
5036 /*
5037  * Have we just finished recovery?  If so, and if we are mounting (or
5038  * remounting) the filesystem readonly, then we will end up with a
5039  * consistent fs on disk.  Record that fact.
5040  */
5041 static void ext4_mark_recovery_complete(struct super_block *sb,
5042 					struct ext4_super_block *es)
5043 {
5044 	journal_t *journal = EXT4_SB(sb)->s_journal;
5045 
5046 	if (!ext4_has_feature_journal(sb)) {
5047 		BUG_ON(journal != NULL);
5048 		return;
5049 	}
5050 	jbd2_journal_lock_updates(journal);
5051 	if (jbd2_journal_flush(journal) < 0)
5052 		goto out;
5053 
5054 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5055 		ext4_clear_feature_journal_needs_recovery(sb);
5056 		ext4_commit_super(sb, 1);
5057 	}
5058 
5059 out:
5060 	jbd2_journal_unlock_updates(journal);
5061 }
5062 
5063 /*
5064  * If we are mounting (or read-write remounting) a filesystem whose journal
5065  * has recorded an error from a previous lifetime, move that error to the
5066  * main filesystem now.
5067  */
5068 static void ext4_clear_journal_err(struct super_block *sb,
5069 				   struct ext4_super_block *es)
5070 {
5071 	journal_t *journal;
5072 	int j_errno;
5073 	const char *errstr;
5074 
5075 	BUG_ON(!ext4_has_feature_journal(sb));
5076 
5077 	journal = EXT4_SB(sb)->s_journal;
5078 
5079 	/*
5080 	 * Now check for any error status which may have been recorded in the
5081 	 * journal by a prior ext4_error() or ext4_abort()
5082 	 */
5083 
5084 	j_errno = jbd2_journal_errno(journal);
5085 	if (j_errno) {
5086 		char nbuf[16];
5087 
5088 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5089 		ext4_warning(sb, "Filesystem error recorded "
5090 			     "from previous mount: %s", errstr);
5091 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5092 
5093 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5094 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5095 		ext4_commit_super(sb, 1);
5096 
5097 		jbd2_journal_clear_err(journal);
5098 		jbd2_journal_update_sb_errno(journal);
5099 	}
5100 }
5101 
5102 /*
5103  * Force the running and committing transactions to commit,
5104  * and wait on the commit.
5105  */
5106 int ext4_force_commit(struct super_block *sb)
5107 {
5108 	journal_t *journal;
5109 
5110 	if (sb_rdonly(sb))
5111 		return 0;
5112 
5113 	journal = EXT4_SB(sb)->s_journal;
5114 	return ext4_journal_force_commit(journal);
5115 }
5116 
5117 static int ext4_sync_fs(struct super_block *sb, int wait)
5118 {
5119 	int ret = 0;
5120 	tid_t target;
5121 	bool needs_barrier = false;
5122 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5123 
5124 	if (unlikely(ext4_forced_shutdown(sbi)))
5125 		return 0;
5126 
5127 	trace_ext4_sync_fs(sb, wait);
5128 	flush_workqueue(sbi->rsv_conversion_wq);
5129 	/*
5130 	 * Writeback quota in non-journalled quota case - journalled quota has
5131 	 * no dirty dquots
5132 	 */
5133 	dquot_writeback_dquots(sb, -1);
5134 	/*
5135 	 * Data writeback is possible w/o journal transaction, so barrier must
5136 	 * being sent at the end of the function. But we can skip it if
5137 	 * transaction_commit will do it for us.
5138 	 */
5139 	if (sbi->s_journal) {
5140 		target = jbd2_get_latest_transaction(sbi->s_journal);
5141 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5142 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5143 			needs_barrier = true;
5144 
5145 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5146 			if (wait)
5147 				ret = jbd2_log_wait_commit(sbi->s_journal,
5148 							   target);
5149 		}
5150 	} else if (wait && test_opt(sb, BARRIER))
5151 		needs_barrier = true;
5152 	if (needs_barrier) {
5153 		int err;
5154 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5155 		if (!ret)
5156 			ret = err;
5157 	}
5158 
5159 	return ret;
5160 }
5161 
5162 /*
5163  * LVM calls this function before a (read-only) snapshot is created.  This
5164  * gives us a chance to flush the journal completely and mark the fs clean.
5165  *
5166  * Note that only this function cannot bring a filesystem to be in a clean
5167  * state independently. It relies on upper layer to stop all data & metadata
5168  * modifications.
5169  */
5170 static int ext4_freeze(struct super_block *sb)
5171 {
5172 	int error = 0;
5173 	journal_t *journal;
5174 
5175 	if (sb_rdonly(sb))
5176 		return 0;
5177 
5178 	journal = EXT4_SB(sb)->s_journal;
5179 
5180 	if (journal) {
5181 		/* Now we set up the journal barrier. */
5182 		jbd2_journal_lock_updates(journal);
5183 
5184 		/*
5185 		 * Don't clear the needs_recovery flag if we failed to
5186 		 * flush the journal.
5187 		 */
5188 		error = jbd2_journal_flush(journal);
5189 		if (error < 0)
5190 			goto out;
5191 
5192 		/* Journal blocked and flushed, clear needs_recovery flag. */
5193 		ext4_clear_feature_journal_needs_recovery(sb);
5194 	}
5195 
5196 	error = ext4_commit_super(sb, 1);
5197 out:
5198 	if (journal)
5199 		/* we rely on upper layer to stop further updates */
5200 		jbd2_journal_unlock_updates(journal);
5201 	return error;
5202 }
5203 
5204 /*
5205  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5206  * flag here, even though the filesystem is not technically dirty yet.
5207  */
5208 static int ext4_unfreeze(struct super_block *sb)
5209 {
5210 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5211 		return 0;
5212 
5213 	if (EXT4_SB(sb)->s_journal) {
5214 		/* Reset the needs_recovery flag before the fs is unlocked. */
5215 		ext4_set_feature_journal_needs_recovery(sb);
5216 	}
5217 
5218 	ext4_commit_super(sb, 1);
5219 	return 0;
5220 }
5221 
5222 /*
5223  * Structure to save mount options for ext4_remount's benefit
5224  */
5225 struct ext4_mount_options {
5226 	unsigned long s_mount_opt;
5227 	unsigned long s_mount_opt2;
5228 	kuid_t s_resuid;
5229 	kgid_t s_resgid;
5230 	unsigned long s_commit_interval;
5231 	u32 s_min_batch_time, s_max_batch_time;
5232 #ifdef CONFIG_QUOTA
5233 	int s_jquota_fmt;
5234 	char *s_qf_names[EXT4_MAXQUOTAS];
5235 #endif
5236 };
5237 
5238 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5239 {
5240 	struct ext4_super_block *es;
5241 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5242 	unsigned long old_sb_flags;
5243 	struct ext4_mount_options old_opts;
5244 	int enable_quota = 0;
5245 	ext4_group_t g;
5246 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5247 	int err = 0;
5248 #ifdef CONFIG_QUOTA
5249 	int i, j;
5250 	char *to_free[EXT4_MAXQUOTAS];
5251 #endif
5252 	char *orig_data = kstrdup(data, GFP_KERNEL);
5253 
5254 	if (data && !orig_data)
5255 		return -ENOMEM;
5256 
5257 	/* Store the original options */
5258 	old_sb_flags = sb->s_flags;
5259 	old_opts.s_mount_opt = sbi->s_mount_opt;
5260 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5261 	old_opts.s_resuid = sbi->s_resuid;
5262 	old_opts.s_resgid = sbi->s_resgid;
5263 	old_opts.s_commit_interval = sbi->s_commit_interval;
5264 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5265 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5266 #ifdef CONFIG_QUOTA
5267 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5268 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5269 		if (sbi->s_qf_names[i]) {
5270 			char *qf_name = get_qf_name(sb, sbi, i);
5271 
5272 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5273 			if (!old_opts.s_qf_names[i]) {
5274 				for (j = 0; j < i; j++)
5275 					kfree(old_opts.s_qf_names[j]);
5276 				kfree(orig_data);
5277 				return -ENOMEM;
5278 			}
5279 		} else
5280 			old_opts.s_qf_names[i] = NULL;
5281 #endif
5282 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5283 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5284 
5285 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5286 		err = -EINVAL;
5287 		goto restore_opts;
5288 	}
5289 
5290 	ext4_clamp_want_extra_isize(sb);
5291 
5292 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5293 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5294 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5295 			 "during remount not supported; ignoring");
5296 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5297 	}
5298 
5299 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5300 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5301 			ext4_msg(sb, KERN_ERR, "can't mount with "
5302 				 "both data=journal and delalloc");
5303 			err = -EINVAL;
5304 			goto restore_opts;
5305 		}
5306 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5307 			ext4_msg(sb, KERN_ERR, "can't mount with "
5308 				 "both data=journal and dioread_nolock");
5309 			err = -EINVAL;
5310 			goto restore_opts;
5311 		}
5312 		if (test_opt(sb, DAX)) {
5313 			ext4_msg(sb, KERN_ERR, "can't mount with "
5314 				 "both data=journal and dax");
5315 			err = -EINVAL;
5316 			goto restore_opts;
5317 		}
5318 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5319 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5320 			ext4_msg(sb, KERN_ERR, "can't mount with "
5321 				"journal_async_commit in data=ordered mode");
5322 			err = -EINVAL;
5323 			goto restore_opts;
5324 		}
5325 	}
5326 
5327 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5328 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5329 		err = -EINVAL;
5330 		goto restore_opts;
5331 	}
5332 
5333 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5334 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5335 			"dax flag with busy inodes while remounting");
5336 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5337 	}
5338 
5339 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5340 		ext4_abort(sb, "Abort forced by user");
5341 
5342 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5343 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5344 
5345 	es = sbi->s_es;
5346 
5347 	if (sbi->s_journal) {
5348 		ext4_init_journal_params(sb, sbi->s_journal);
5349 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5350 	}
5351 
5352 	if (*flags & SB_LAZYTIME)
5353 		sb->s_flags |= SB_LAZYTIME;
5354 
5355 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5356 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5357 			err = -EROFS;
5358 			goto restore_opts;
5359 		}
5360 
5361 		if (*flags & SB_RDONLY) {
5362 			err = sync_filesystem(sb);
5363 			if (err < 0)
5364 				goto restore_opts;
5365 			err = dquot_suspend(sb, -1);
5366 			if (err < 0)
5367 				goto restore_opts;
5368 
5369 			/*
5370 			 * First of all, the unconditional stuff we have to do
5371 			 * to disable replay of the journal when we next remount
5372 			 */
5373 			sb->s_flags |= SB_RDONLY;
5374 
5375 			/*
5376 			 * OK, test if we are remounting a valid rw partition
5377 			 * readonly, and if so set the rdonly flag and then
5378 			 * mark the partition as valid again.
5379 			 */
5380 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5381 			    (sbi->s_mount_state & EXT4_VALID_FS))
5382 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5383 
5384 			if (sbi->s_journal)
5385 				ext4_mark_recovery_complete(sb, es);
5386 			if (sbi->s_mmp_tsk)
5387 				kthread_stop(sbi->s_mmp_tsk);
5388 		} else {
5389 			/* Make sure we can mount this feature set readwrite */
5390 			if (ext4_has_feature_readonly(sb) ||
5391 			    !ext4_feature_set_ok(sb, 0)) {
5392 				err = -EROFS;
5393 				goto restore_opts;
5394 			}
5395 			/*
5396 			 * Make sure the group descriptor checksums
5397 			 * are sane.  If they aren't, refuse to remount r/w.
5398 			 */
5399 			for (g = 0; g < sbi->s_groups_count; g++) {
5400 				struct ext4_group_desc *gdp =
5401 					ext4_get_group_desc(sb, g, NULL);
5402 
5403 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5404 					ext4_msg(sb, KERN_ERR,
5405 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5406 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5407 					       le16_to_cpu(gdp->bg_checksum));
5408 					err = -EFSBADCRC;
5409 					goto restore_opts;
5410 				}
5411 			}
5412 
5413 			/*
5414 			 * If we have an unprocessed orphan list hanging
5415 			 * around from a previously readonly bdev mount,
5416 			 * require a full umount/remount for now.
5417 			 */
5418 			if (es->s_last_orphan) {
5419 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5420 				       "remount RDWR because of unprocessed "
5421 				       "orphan inode list.  Please "
5422 				       "umount/remount instead");
5423 				err = -EINVAL;
5424 				goto restore_opts;
5425 			}
5426 
5427 			/*
5428 			 * Mounting a RDONLY partition read-write, so reread
5429 			 * and store the current valid flag.  (It may have
5430 			 * been changed by e2fsck since we originally mounted
5431 			 * the partition.)
5432 			 */
5433 			if (sbi->s_journal)
5434 				ext4_clear_journal_err(sb, es);
5435 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5436 
5437 			err = ext4_setup_super(sb, es, 0);
5438 			if (err)
5439 				goto restore_opts;
5440 
5441 			sb->s_flags &= ~SB_RDONLY;
5442 			if (ext4_has_feature_mmp(sb))
5443 				if (ext4_multi_mount_protect(sb,
5444 						le64_to_cpu(es->s_mmp_block))) {
5445 					err = -EROFS;
5446 					goto restore_opts;
5447 				}
5448 			enable_quota = 1;
5449 		}
5450 	}
5451 
5452 	/*
5453 	 * Reinitialize lazy itable initialization thread based on
5454 	 * current settings
5455 	 */
5456 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5457 		ext4_unregister_li_request(sb);
5458 	else {
5459 		ext4_group_t first_not_zeroed;
5460 		first_not_zeroed = ext4_has_uninit_itable(sb);
5461 		ext4_register_li_request(sb, first_not_zeroed);
5462 	}
5463 
5464 	ext4_setup_system_zone(sb);
5465 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5466 		err = ext4_commit_super(sb, 1);
5467 		if (err)
5468 			goto restore_opts;
5469 	}
5470 
5471 #ifdef CONFIG_QUOTA
5472 	/* Release old quota file names */
5473 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5474 		kfree(old_opts.s_qf_names[i]);
5475 	if (enable_quota) {
5476 		if (sb_any_quota_suspended(sb))
5477 			dquot_resume(sb, -1);
5478 		else if (ext4_has_feature_quota(sb)) {
5479 			err = ext4_enable_quotas(sb);
5480 			if (err)
5481 				goto restore_opts;
5482 		}
5483 	}
5484 #endif
5485 
5486 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5487 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5488 	kfree(orig_data);
5489 	return 0;
5490 
5491 restore_opts:
5492 	sb->s_flags = old_sb_flags;
5493 	sbi->s_mount_opt = old_opts.s_mount_opt;
5494 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5495 	sbi->s_resuid = old_opts.s_resuid;
5496 	sbi->s_resgid = old_opts.s_resgid;
5497 	sbi->s_commit_interval = old_opts.s_commit_interval;
5498 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5499 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5500 #ifdef CONFIG_QUOTA
5501 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5502 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5503 		to_free[i] = get_qf_name(sb, sbi, i);
5504 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5505 	}
5506 	synchronize_rcu();
5507 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5508 		kfree(to_free[i]);
5509 #endif
5510 	kfree(orig_data);
5511 	return err;
5512 }
5513 
5514 #ifdef CONFIG_QUOTA
5515 static int ext4_statfs_project(struct super_block *sb,
5516 			       kprojid_t projid, struct kstatfs *buf)
5517 {
5518 	struct kqid qid;
5519 	struct dquot *dquot;
5520 	u64 limit;
5521 	u64 curblock;
5522 
5523 	qid = make_kqid_projid(projid);
5524 	dquot = dqget(sb, qid);
5525 	if (IS_ERR(dquot))
5526 		return PTR_ERR(dquot);
5527 	spin_lock(&dquot->dq_dqb_lock);
5528 
5529 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5530 		 dquot->dq_dqb.dqb_bsoftlimit :
5531 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5532 	if (limit && buf->f_blocks > limit) {
5533 		curblock = (dquot->dq_dqb.dqb_curspace +
5534 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5535 		buf->f_blocks = limit;
5536 		buf->f_bfree = buf->f_bavail =
5537 			(buf->f_blocks > curblock) ?
5538 			 (buf->f_blocks - curblock) : 0;
5539 	}
5540 
5541 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5542 		dquot->dq_dqb.dqb_isoftlimit :
5543 		dquot->dq_dqb.dqb_ihardlimit;
5544 	if (limit && buf->f_files > limit) {
5545 		buf->f_files = limit;
5546 		buf->f_ffree =
5547 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5548 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5549 	}
5550 
5551 	spin_unlock(&dquot->dq_dqb_lock);
5552 	dqput(dquot);
5553 	return 0;
5554 }
5555 #endif
5556 
5557 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5558 {
5559 	struct super_block *sb = dentry->d_sb;
5560 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5561 	struct ext4_super_block *es = sbi->s_es;
5562 	ext4_fsblk_t overhead = 0, resv_blocks;
5563 	u64 fsid;
5564 	s64 bfree;
5565 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5566 
5567 	if (!test_opt(sb, MINIX_DF))
5568 		overhead = sbi->s_overhead;
5569 
5570 	buf->f_type = EXT4_SUPER_MAGIC;
5571 	buf->f_bsize = sb->s_blocksize;
5572 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5573 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5574 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5575 	/* prevent underflow in case that few free space is available */
5576 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5577 	buf->f_bavail = buf->f_bfree -
5578 			(ext4_r_blocks_count(es) + resv_blocks);
5579 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5580 		buf->f_bavail = 0;
5581 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5582 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5583 	buf->f_namelen = EXT4_NAME_LEN;
5584 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5585 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5586 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5587 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5588 
5589 #ifdef CONFIG_QUOTA
5590 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5591 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5592 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5593 #endif
5594 	return 0;
5595 }
5596 
5597 
5598 #ifdef CONFIG_QUOTA
5599 
5600 /*
5601  * Helper functions so that transaction is started before we acquire dqio_sem
5602  * to keep correct lock ordering of transaction > dqio_sem
5603  */
5604 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5605 {
5606 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5607 }
5608 
5609 static int ext4_write_dquot(struct dquot *dquot)
5610 {
5611 	int ret, err;
5612 	handle_t *handle;
5613 	struct inode *inode;
5614 
5615 	inode = dquot_to_inode(dquot);
5616 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5617 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5618 	if (IS_ERR(handle))
5619 		return PTR_ERR(handle);
5620 	ret = dquot_commit(dquot);
5621 	err = ext4_journal_stop(handle);
5622 	if (!ret)
5623 		ret = err;
5624 	return ret;
5625 }
5626 
5627 static int ext4_acquire_dquot(struct dquot *dquot)
5628 {
5629 	int ret, err;
5630 	handle_t *handle;
5631 
5632 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5633 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5634 	if (IS_ERR(handle))
5635 		return PTR_ERR(handle);
5636 	ret = dquot_acquire(dquot);
5637 	err = ext4_journal_stop(handle);
5638 	if (!ret)
5639 		ret = err;
5640 	return ret;
5641 }
5642 
5643 static int ext4_release_dquot(struct dquot *dquot)
5644 {
5645 	int ret, err;
5646 	handle_t *handle;
5647 
5648 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5649 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5650 	if (IS_ERR(handle)) {
5651 		/* Release dquot anyway to avoid endless cycle in dqput() */
5652 		dquot_release(dquot);
5653 		return PTR_ERR(handle);
5654 	}
5655 	ret = dquot_release(dquot);
5656 	err = ext4_journal_stop(handle);
5657 	if (!ret)
5658 		ret = err;
5659 	return ret;
5660 }
5661 
5662 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5663 {
5664 	struct super_block *sb = dquot->dq_sb;
5665 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5666 
5667 	/* Are we journaling quotas? */
5668 	if (ext4_has_feature_quota(sb) ||
5669 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5670 		dquot_mark_dquot_dirty(dquot);
5671 		return ext4_write_dquot(dquot);
5672 	} else {
5673 		return dquot_mark_dquot_dirty(dquot);
5674 	}
5675 }
5676 
5677 static int ext4_write_info(struct super_block *sb, int type)
5678 {
5679 	int ret, err;
5680 	handle_t *handle;
5681 
5682 	/* Data block + inode block */
5683 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5684 	if (IS_ERR(handle))
5685 		return PTR_ERR(handle);
5686 	ret = dquot_commit_info(sb, type);
5687 	err = ext4_journal_stop(handle);
5688 	if (!ret)
5689 		ret = err;
5690 	return ret;
5691 }
5692 
5693 /*
5694  * Turn on quotas during mount time - we need to find
5695  * the quota file and such...
5696  */
5697 static int ext4_quota_on_mount(struct super_block *sb, int type)
5698 {
5699 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5700 					EXT4_SB(sb)->s_jquota_fmt, type);
5701 }
5702 
5703 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5704 {
5705 	struct ext4_inode_info *ei = EXT4_I(inode);
5706 
5707 	/* The first argument of lockdep_set_subclass has to be
5708 	 * *exactly* the same as the argument to init_rwsem() --- in
5709 	 * this case, in init_once() --- or lockdep gets unhappy
5710 	 * because the name of the lock is set using the
5711 	 * stringification of the argument to init_rwsem().
5712 	 */
5713 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5714 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5715 }
5716 
5717 /*
5718  * Standard function to be called on quota_on
5719  */
5720 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5721 			 const struct path *path)
5722 {
5723 	int err;
5724 
5725 	if (!test_opt(sb, QUOTA))
5726 		return -EINVAL;
5727 
5728 	/* Quotafile not on the same filesystem? */
5729 	if (path->dentry->d_sb != sb)
5730 		return -EXDEV;
5731 	/* Journaling quota? */
5732 	if (EXT4_SB(sb)->s_qf_names[type]) {
5733 		/* Quotafile not in fs root? */
5734 		if (path->dentry->d_parent != sb->s_root)
5735 			ext4_msg(sb, KERN_WARNING,
5736 				"Quota file not on filesystem root. "
5737 				"Journaled quota will not work");
5738 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5739 	} else {
5740 		/*
5741 		 * Clear the flag just in case mount options changed since
5742 		 * last time.
5743 		 */
5744 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5745 	}
5746 
5747 	/*
5748 	 * When we journal data on quota file, we have to flush journal to see
5749 	 * all updates to the file when we bypass pagecache...
5750 	 */
5751 	if (EXT4_SB(sb)->s_journal &&
5752 	    ext4_should_journal_data(d_inode(path->dentry))) {
5753 		/*
5754 		 * We don't need to lock updates but journal_flush() could
5755 		 * otherwise be livelocked...
5756 		 */
5757 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5758 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5759 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5760 		if (err)
5761 			return err;
5762 	}
5763 
5764 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5765 	err = dquot_quota_on(sb, type, format_id, path);
5766 	if (err) {
5767 		lockdep_set_quota_inode(path->dentry->d_inode,
5768 					     I_DATA_SEM_NORMAL);
5769 	} else {
5770 		struct inode *inode = d_inode(path->dentry);
5771 		handle_t *handle;
5772 
5773 		/*
5774 		 * Set inode flags to prevent userspace from messing with quota
5775 		 * files. If this fails, we return success anyway since quotas
5776 		 * are already enabled and this is not a hard failure.
5777 		 */
5778 		inode_lock(inode);
5779 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5780 		if (IS_ERR(handle))
5781 			goto unlock_inode;
5782 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5783 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5784 				S_NOATIME | S_IMMUTABLE);
5785 		ext4_mark_inode_dirty(handle, inode);
5786 		ext4_journal_stop(handle);
5787 	unlock_inode:
5788 		inode_unlock(inode);
5789 	}
5790 	return err;
5791 }
5792 
5793 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5794 			     unsigned int flags)
5795 {
5796 	int err;
5797 	struct inode *qf_inode;
5798 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5799 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5800 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5801 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5802 	};
5803 
5804 	BUG_ON(!ext4_has_feature_quota(sb));
5805 
5806 	if (!qf_inums[type])
5807 		return -EPERM;
5808 
5809 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5810 	if (IS_ERR(qf_inode)) {
5811 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5812 		return PTR_ERR(qf_inode);
5813 	}
5814 
5815 	/* Don't account quota for quota files to avoid recursion */
5816 	qf_inode->i_flags |= S_NOQUOTA;
5817 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5818 	err = dquot_enable(qf_inode, type, format_id, flags);
5819 	if (err)
5820 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5821 	iput(qf_inode);
5822 
5823 	return err;
5824 }
5825 
5826 /* Enable usage tracking for all quota types. */
5827 static int ext4_enable_quotas(struct super_block *sb)
5828 {
5829 	int type, err = 0;
5830 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5831 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5832 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5833 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5834 	};
5835 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5836 		test_opt(sb, USRQUOTA),
5837 		test_opt(sb, GRPQUOTA),
5838 		test_opt(sb, PRJQUOTA),
5839 	};
5840 
5841 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5842 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5843 		if (qf_inums[type]) {
5844 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5845 				DQUOT_USAGE_ENABLED |
5846 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5847 			if (err) {
5848 				ext4_warning(sb,
5849 					"Failed to enable quota tracking "
5850 					"(type=%d, err=%d). Please run "
5851 					"e2fsck to fix.", type, err);
5852 				for (type--; type >= 0; type--)
5853 					dquot_quota_off(sb, type);
5854 
5855 				return err;
5856 			}
5857 		}
5858 	}
5859 	return 0;
5860 }
5861 
5862 static int ext4_quota_off(struct super_block *sb, int type)
5863 {
5864 	struct inode *inode = sb_dqopt(sb)->files[type];
5865 	handle_t *handle;
5866 	int err;
5867 
5868 	/* Force all delayed allocation blocks to be allocated.
5869 	 * Caller already holds s_umount sem */
5870 	if (test_opt(sb, DELALLOC))
5871 		sync_filesystem(sb);
5872 
5873 	if (!inode || !igrab(inode))
5874 		goto out;
5875 
5876 	err = dquot_quota_off(sb, type);
5877 	if (err || ext4_has_feature_quota(sb))
5878 		goto out_put;
5879 
5880 	inode_lock(inode);
5881 	/*
5882 	 * Update modification times of quota files when userspace can
5883 	 * start looking at them. If we fail, we return success anyway since
5884 	 * this is not a hard failure and quotas are already disabled.
5885 	 */
5886 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5887 	if (IS_ERR(handle))
5888 		goto out_unlock;
5889 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5890 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5891 	inode->i_mtime = inode->i_ctime = current_time(inode);
5892 	ext4_mark_inode_dirty(handle, inode);
5893 	ext4_journal_stop(handle);
5894 out_unlock:
5895 	inode_unlock(inode);
5896 out_put:
5897 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5898 	iput(inode);
5899 	return err;
5900 out:
5901 	return dquot_quota_off(sb, type);
5902 }
5903 
5904 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5905  * acquiring the locks... As quota files are never truncated and quota code
5906  * itself serializes the operations (and no one else should touch the files)
5907  * we don't have to be afraid of races */
5908 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5909 			       size_t len, loff_t off)
5910 {
5911 	struct inode *inode = sb_dqopt(sb)->files[type];
5912 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5913 	int offset = off & (sb->s_blocksize - 1);
5914 	int tocopy;
5915 	size_t toread;
5916 	struct buffer_head *bh;
5917 	loff_t i_size = i_size_read(inode);
5918 
5919 	if (off > i_size)
5920 		return 0;
5921 	if (off+len > i_size)
5922 		len = i_size-off;
5923 	toread = len;
5924 	while (toread > 0) {
5925 		tocopy = sb->s_blocksize - offset < toread ?
5926 				sb->s_blocksize - offset : toread;
5927 		bh = ext4_bread(NULL, inode, blk, 0);
5928 		if (IS_ERR(bh))
5929 			return PTR_ERR(bh);
5930 		if (!bh)	/* A hole? */
5931 			memset(data, 0, tocopy);
5932 		else
5933 			memcpy(data, bh->b_data+offset, tocopy);
5934 		brelse(bh);
5935 		offset = 0;
5936 		toread -= tocopy;
5937 		data += tocopy;
5938 		blk++;
5939 	}
5940 	return len;
5941 }
5942 
5943 /* Write to quotafile (we know the transaction is already started and has
5944  * enough credits) */
5945 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5946 				const char *data, size_t len, loff_t off)
5947 {
5948 	struct inode *inode = sb_dqopt(sb)->files[type];
5949 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5950 	int err, offset = off & (sb->s_blocksize - 1);
5951 	int retries = 0;
5952 	struct buffer_head *bh;
5953 	handle_t *handle = journal_current_handle();
5954 
5955 	if (EXT4_SB(sb)->s_journal && !handle) {
5956 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5957 			" cancelled because transaction is not started",
5958 			(unsigned long long)off, (unsigned long long)len);
5959 		return -EIO;
5960 	}
5961 	/*
5962 	 * Since we account only one data block in transaction credits,
5963 	 * then it is impossible to cross a block boundary.
5964 	 */
5965 	if (sb->s_blocksize - offset < len) {
5966 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5967 			" cancelled because not block aligned",
5968 			(unsigned long long)off, (unsigned long long)len);
5969 		return -EIO;
5970 	}
5971 
5972 	do {
5973 		bh = ext4_bread(handle, inode, blk,
5974 				EXT4_GET_BLOCKS_CREATE |
5975 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5976 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5977 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5978 	if (IS_ERR(bh))
5979 		return PTR_ERR(bh);
5980 	if (!bh)
5981 		goto out;
5982 	BUFFER_TRACE(bh, "get write access");
5983 	err = ext4_journal_get_write_access(handle, bh);
5984 	if (err) {
5985 		brelse(bh);
5986 		return err;
5987 	}
5988 	lock_buffer(bh);
5989 	memcpy(bh->b_data+offset, data, len);
5990 	flush_dcache_page(bh->b_page);
5991 	unlock_buffer(bh);
5992 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5993 	brelse(bh);
5994 out:
5995 	if (inode->i_size < off + len) {
5996 		i_size_write(inode, off + len);
5997 		EXT4_I(inode)->i_disksize = inode->i_size;
5998 		ext4_mark_inode_dirty(handle, inode);
5999 	}
6000 	return len;
6001 }
6002 
6003 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
6004 {
6005 	const struct quota_format_ops	*ops;
6006 
6007 	if (!sb_has_quota_loaded(sb, qid->type))
6008 		return -ESRCH;
6009 	ops = sb_dqopt(sb)->ops[qid->type];
6010 	if (!ops || !ops->get_next_id)
6011 		return -ENOSYS;
6012 	return dquot_get_next_id(sb, qid);
6013 }
6014 #endif
6015 
6016 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6017 		       const char *dev_name, void *data)
6018 {
6019 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6020 }
6021 
6022 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6023 static inline void register_as_ext2(void)
6024 {
6025 	int err = register_filesystem(&ext2_fs_type);
6026 	if (err)
6027 		printk(KERN_WARNING
6028 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6029 }
6030 
6031 static inline void unregister_as_ext2(void)
6032 {
6033 	unregister_filesystem(&ext2_fs_type);
6034 }
6035 
6036 static inline int ext2_feature_set_ok(struct super_block *sb)
6037 {
6038 	if (ext4_has_unknown_ext2_incompat_features(sb))
6039 		return 0;
6040 	if (sb_rdonly(sb))
6041 		return 1;
6042 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6043 		return 0;
6044 	return 1;
6045 }
6046 #else
6047 static inline void register_as_ext2(void) { }
6048 static inline void unregister_as_ext2(void) { }
6049 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6050 #endif
6051 
6052 static inline void register_as_ext3(void)
6053 {
6054 	int err = register_filesystem(&ext3_fs_type);
6055 	if (err)
6056 		printk(KERN_WARNING
6057 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6058 }
6059 
6060 static inline void unregister_as_ext3(void)
6061 {
6062 	unregister_filesystem(&ext3_fs_type);
6063 }
6064 
6065 static inline int ext3_feature_set_ok(struct super_block *sb)
6066 {
6067 	if (ext4_has_unknown_ext3_incompat_features(sb))
6068 		return 0;
6069 	if (!ext4_has_feature_journal(sb))
6070 		return 0;
6071 	if (sb_rdonly(sb))
6072 		return 1;
6073 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6074 		return 0;
6075 	return 1;
6076 }
6077 
6078 static struct file_system_type ext4_fs_type = {
6079 	.owner		= THIS_MODULE,
6080 	.name		= "ext4",
6081 	.mount		= ext4_mount,
6082 	.kill_sb	= kill_block_super,
6083 	.fs_flags	= FS_REQUIRES_DEV,
6084 };
6085 MODULE_ALIAS_FS("ext4");
6086 
6087 /* Shared across all ext4 file systems */
6088 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6089 
6090 static int __init ext4_init_fs(void)
6091 {
6092 	int i, err;
6093 
6094 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6095 	ext4_li_info = NULL;
6096 	mutex_init(&ext4_li_mtx);
6097 
6098 	/* Build-time check for flags consistency */
6099 	ext4_check_flag_values();
6100 
6101 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6102 		init_waitqueue_head(&ext4__ioend_wq[i]);
6103 
6104 	err = ext4_init_es();
6105 	if (err)
6106 		return err;
6107 
6108 	err = ext4_init_pending();
6109 	if (err)
6110 		goto out7;
6111 
6112 	err = ext4_init_post_read_processing();
6113 	if (err)
6114 		goto out6;
6115 
6116 	err = ext4_init_pageio();
6117 	if (err)
6118 		goto out5;
6119 
6120 	err = ext4_init_system_zone();
6121 	if (err)
6122 		goto out4;
6123 
6124 	err = ext4_init_sysfs();
6125 	if (err)
6126 		goto out3;
6127 
6128 	err = ext4_init_mballoc();
6129 	if (err)
6130 		goto out2;
6131 	err = init_inodecache();
6132 	if (err)
6133 		goto out1;
6134 	register_as_ext3();
6135 	register_as_ext2();
6136 	err = register_filesystem(&ext4_fs_type);
6137 	if (err)
6138 		goto out;
6139 
6140 	return 0;
6141 out:
6142 	unregister_as_ext2();
6143 	unregister_as_ext3();
6144 	destroy_inodecache();
6145 out1:
6146 	ext4_exit_mballoc();
6147 out2:
6148 	ext4_exit_sysfs();
6149 out3:
6150 	ext4_exit_system_zone();
6151 out4:
6152 	ext4_exit_pageio();
6153 out5:
6154 	ext4_exit_post_read_processing();
6155 out6:
6156 	ext4_exit_pending();
6157 out7:
6158 	ext4_exit_es();
6159 
6160 	return err;
6161 }
6162 
6163 static void __exit ext4_exit_fs(void)
6164 {
6165 	ext4_destroy_lazyinit_thread();
6166 	unregister_as_ext2();
6167 	unregister_as_ext3();
6168 	unregister_filesystem(&ext4_fs_type);
6169 	destroy_inodecache();
6170 	ext4_exit_mballoc();
6171 	ext4_exit_sysfs();
6172 	ext4_exit_system_zone();
6173 	ext4_exit_pageio();
6174 	ext4_exit_post_read_processing();
6175 	ext4_exit_es();
6176 	ext4_exit_pending();
6177 }
6178 
6179 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6180 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6181 MODULE_LICENSE("GPL");
6182 MODULE_SOFTDEP("pre: crc32c");
6183 module_init(ext4_init_fs)
6184 module_exit(ext4_exit_fs)
6185