xref: /openbmc/linux/fs/ext4/super.c (revision aeb64ff3)
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 	ext4_discard_preallocations(inode);
1176 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1177 	dquot_drop(inode);
1178 	if (EXT4_I(inode)->jinode) {
1179 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1180 					       EXT4_I(inode)->jinode);
1181 		jbd2_free_inode(EXT4_I(inode)->jinode);
1182 		EXT4_I(inode)->jinode = NULL;
1183 	}
1184 	fscrypt_put_encryption_info(inode);
1185 	fsverity_cleanup_inode(inode);
1186 }
1187 
1188 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1189 					u64 ino, u32 generation)
1190 {
1191 	struct inode *inode;
1192 
1193 	/*
1194 	 * Currently we don't know the generation for parent directory, so
1195 	 * a generation of 0 means "accept any"
1196 	 */
1197 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1198 	if (IS_ERR(inode))
1199 		return ERR_CAST(inode);
1200 	if (generation && inode->i_generation != generation) {
1201 		iput(inode);
1202 		return ERR_PTR(-ESTALE);
1203 	}
1204 
1205 	return inode;
1206 }
1207 
1208 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1209 					int fh_len, int fh_type)
1210 {
1211 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1212 				    ext4_nfs_get_inode);
1213 }
1214 
1215 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1216 					int fh_len, int fh_type)
1217 {
1218 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1219 				    ext4_nfs_get_inode);
1220 }
1221 
1222 static int ext4_nfs_commit_metadata(struct inode *inode)
1223 {
1224 	struct writeback_control wbc = {
1225 		.sync_mode = WB_SYNC_ALL
1226 	};
1227 
1228 	trace_ext4_nfs_commit_metadata(inode);
1229 	return ext4_write_inode(inode, &wbc);
1230 }
1231 
1232 /*
1233  * Try to release metadata pages (indirect blocks, directories) which are
1234  * mapped via the block device.  Since these pages could have journal heads
1235  * which would prevent try_to_free_buffers() from freeing them, we must use
1236  * jbd2 layer's try_to_free_buffers() function to release them.
1237  */
1238 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1239 				 gfp_t wait)
1240 {
1241 	journal_t *journal = EXT4_SB(sb)->s_journal;
1242 
1243 	WARN_ON(PageChecked(page));
1244 	if (!page_has_buffers(page))
1245 		return 0;
1246 	if (journal)
1247 		return jbd2_journal_try_to_free_buffers(journal, page,
1248 						wait & ~__GFP_DIRECT_RECLAIM);
1249 	return try_to_free_buffers(page);
1250 }
1251 
1252 #ifdef CONFIG_FS_ENCRYPTION
1253 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1254 {
1255 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1256 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1257 }
1258 
1259 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1260 							void *fs_data)
1261 {
1262 	handle_t *handle = fs_data;
1263 	int res, res2, credits, retries = 0;
1264 
1265 	/*
1266 	 * Encrypting the root directory is not allowed because e2fsck expects
1267 	 * lost+found to exist and be unencrypted, and encrypting the root
1268 	 * directory would imply encrypting the lost+found directory as well as
1269 	 * the filename "lost+found" itself.
1270 	 */
1271 	if (inode->i_ino == EXT4_ROOT_INO)
1272 		return -EPERM;
1273 
1274 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1275 		return -EINVAL;
1276 
1277 	res = ext4_convert_inline_data(inode);
1278 	if (res)
1279 		return res;
1280 
1281 	/*
1282 	 * If a journal handle was specified, then the encryption context is
1283 	 * being set on a new inode via inheritance and is part of a larger
1284 	 * transaction to create the inode.  Otherwise the encryption context is
1285 	 * being set on an existing inode in its own transaction.  Only in the
1286 	 * latter case should the "retry on ENOSPC" logic be used.
1287 	 */
1288 
1289 	if (handle) {
1290 		res = ext4_xattr_set_handle(handle, inode,
1291 					    EXT4_XATTR_INDEX_ENCRYPTION,
1292 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1293 					    ctx, len, 0);
1294 		if (!res) {
1295 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1296 			ext4_clear_inode_state(inode,
1297 					EXT4_STATE_MAY_INLINE_DATA);
1298 			/*
1299 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1300 			 * S_DAX may be disabled
1301 			 */
1302 			ext4_set_inode_flags(inode);
1303 		}
1304 		return res;
1305 	}
1306 
1307 	res = dquot_initialize(inode);
1308 	if (res)
1309 		return res;
1310 retry:
1311 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1312 				     &credits);
1313 	if (res)
1314 		return res;
1315 
1316 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1317 	if (IS_ERR(handle))
1318 		return PTR_ERR(handle);
1319 
1320 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1321 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1322 				    ctx, len, 0);
1323 	if (!res) {
1324 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1325 		/*
1326 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1327 		 * S_DAX may be disabled
1328 		 */
1329 		ext4_set_inode_flags(inode);
1330 		res = ext4_mark_inode_dirty(handle, inode);
1331 		if (res)
1332 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1333 	}
1334 	res2 = ext4_journal_stop(handle);
1335 
1336 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1337 		goto retry;
1338 	if (!res)
1339 		res = res2;
1340 	return res;
1341 }
1342 
1343 static bool ext4_dummy_context(struct inode *inode)
1344 {
1345 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1346 }
1347 
1348 static bool ext4_has_stable_inodes(struct super_block *sb)
1349 {
1350 	return ext4_has_feature_stable_inodes(sb);
1351 }
1352 
1353 static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
1354 				       int *ino_bits_ret, int *lblk_bits_ret)
1355 {
1356 	*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
1357 	*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
1358 }
1359 
1360 static const struct fscrypt_operations ext4_cryptops = {
1361 	.key_prefix		= "ext4:",
1362 	.get_context		= ext4_get_context,
1363 	.set_context		= ext4_set_context,
1364 	.dummy_context		= ext4_dummy_context,
1365 	.empty_dir		= ext4_empty_dir,
1366 	.max_namelen		= EXT4_NAME_LEN,
1367 	.has_stable_inodes	= ext4_has_stable_inodes,
1368 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
1369 };
1370 #endif
1371 
1372 #ifdef CONFIG_QUOTA
1373 static const char * const quotatypes[] = INITQFNAMES;
1374 #define QTYPE2NAME(t) (quotatypes[t])
1375 
1376 static int ext4_write_dquot(struct dquot *dquot);
1377 static int ext4_acquire_dquot(struct dquot *dquot);
1378 static int ext4_release_dquot(struct dquot *dquot);
1379 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1380 static int ext4_write_info(struct super_block *sb, int type);
1381 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1382 			 const struct path *path);
1383 static int ext4_quota_on_mount(struct super_block *sb, int type);
1384 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1385 			       size_t len, loff_t off);
1386 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1387 				const char *data, size_t len, loff_t off);
1388 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1389 			     unsigned int flags);
1390 static int ext4_enable_quotas(struct super_block *sb);
1391 
1392 static struct dquot **ext4_get_dquots(struct inode *inode)
1393 {
1394 	return EXT4_I(inode)->i_dquot;
1395 }
1396 
1397 static const struct dquot_operations ext4_quota_operations = {
1398 	.get_reserved_space	= ext4_get_reserved_space,
1399 	.write_dquot		= ext4_write_dquot,
1400 	.acquire_dquot		= ext4_acquire_dquot,
1401 	.release_dquot		= ext4_release_dquot,
1402 	.mark_dirty		= ext4_mark_dquot_dirty,
1403 	.write_info		= ext4_write_info,
1404 	.alloc_dquot		= dquot_alloc,
1405 	.destroy_dquot		= dquot_destroy,
1406 	.get_projid		= ext4_get_projid,
1407 	.get_inode_usage	= ext4_get_inode_usage,
1408 	.get_next_id		= dquot_get_next_id,
1409 };
1410 
1411 static const struct quotactl_ops ext4_qctl_operations = {
1412 	.quota_on	= ext4_quota_on,
1413 	.quota_off	= ext4_quota_off,
1414 	.quota_sync	= dquot_quota_sync,
1415 	.get_state	= dquot_get_state,
1416 	.set_info	= dquot_set_dqinfo,
1417 	.get_dqblk	= dquot_get_dqblk,
1418 	.set_dqblk	= dquot_set_dqblk,
1419 	.get_nextdqblk	= dquot_get_next_dqblk,
1420 };
1421 #endif
1422 
1423 static const struct super_operations ext4_sops = {
1424 	.alloc_inode	= ext4_alloc_inode,
1425 	.free_inode	= ext4_free_in_core_inode,
1426 	.destroy_inode	= ext4_destroy_inode,
1427 	.write_inode	= ext4_write_inode,
1428 	.dirty_inode	= ext4_dirty_inode,
1429 	.drop_inode	= ext4_drop_inode,
1430 	.evict_inode	= ext4_evict_inode,
1431 	.put_super	= ext4_put_super,
1432 	.sync_fs	= ext4_sync_fs,
1433 	.freeze_fs	= ext4_freeze,
1434 	.unfreeze_fs	= ext4_unfreeze,
1435 	.statfs		= ext4_statfs,
1436 	.remount_fs	= ext4_remount,
1437 	.show_options	= ext4_show_options,
1438 #ifdef CONFIG_QUOTA
1439 	.quota_read	= ext4_quota_read,
1440 	.quota_write	= ext4_quota_write,
1441 	.get_dquots	= ext4_get_dquots,
1442 #endif
1443 	.bdev_try_to_free_page = bdev_try_to_free_page,
1444 };
1445 
1446 static const struct export_operations ext4_export_ops = {
1447 	.fh_to_dentry = ext4_fh_to_dentry,
1448 	.fh_to_parent = ext4_fh_to_parent,
1449 	.get_parent = ext4_get_parent,
1450 	.commit_metadata = ext4_nfs_commit_metadata,
1451 };
1452 
1453 enum {
1454 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1455 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1456 	Opt_nouid32, Opt_debug, Opt_removed,
1457 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1458 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1459 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1460 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1461 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1462 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1463 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1464 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1465 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1466 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1467 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1468 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1469 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1470 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1471 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1472 	Opt_dioread_nolock, Opt_dioread_lock,
1473 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1474 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1475 };
1476 
1477 static const match_table_t tokens = {
1478 	{Opt_bsd_df, "bsddf"},
1479 	{Opt_minix_df, "minixdf"},
1480 	{Opt_grpid, "grpid"},
1481 	{Opt_grpid, "bsdgroups"},
1482 	{Opt_nogrpid, "nogrpid"},
1483 	{Opt_nogrpid, "sysvgroups"},
1484 	{Opt_resgid, "resgid=%u"},
1485 	{Opt_resuid, "resuid=%u"},
1486 	{Opt_sb, "sb=%u"},
1487 	{Opt_err_cont, "errors=continue"},
1488 	{Opt_err_panic, "errors=panic"},
1489 	{Opt_err_ro, "errors=remount-ro"},
1490 	{Opt_nouid32, "nouid32"},
1491 	{Opt_debug, "debug"},
1492 	{Opt_removed, "oldalloc"},
1493 	{Opt_removed, "orlov"},
1494 	{Opt_user_xattr, "user_xattr"},
1495 	{Opt_nouser_xattr, "nouser_xattr"},
1496 	{Opt_acl, "acl"},
1497 	{Opt_noacl, "noacl"},
1498 	{Opt_noload, "norecovery"},
1499 	{Opt_noload, "noload"},
1500 	{Opt_removed, "nobh"},
1501 	{Opt_removed, "bh"},
1502 	{Opt_commit, "commit=%u"},
1503 	{Opt_min_batch_time, "min_batch_time=%u"},
1504 	{Opt_max_batch_time, "max_batch_time=%u"},
1505 	{Opt_journal_dev, "journal_dev=%u"},
1506 	{Opt_journal_path, "journal_path=%s"},
1507 	{Opt_journal_checksum, "journal_checksum"},
1508 	{Opt_nojournal_checksum, "nojournal_checksum"},
1509 	{Opt_journal_async_commit, "journal_async_commit"},
1510 	{Opt_abort, "abort"},
1511 	{Opt_data_journal, "data=journal"},
1512 	{Opt_data_ordered, "data=ordered"},
1513 	{Opt_data_writeback, "data=writeback"},
1514 	{Opt_data_err_abort, "data_err=abort"},
1515 	{Opt_data_err_ignore, "data_err=ignore"},
1516 	{Opt_offusrjquota, "usrjquota="},
1517 	{Opt_usrjquota, "usrjquota=%s"},
1518 	{Opt_offgrpjquota, "grpjquota="},
1519 	{Opt_grpjquota, "grpjquota=%s"},
1520 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1521 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1522 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1523 	{Opt_grpquota, "grpquota"},
1524 	{Opt_noquota, "noquota"},
1525 	{Opt_quota, "quota"},
1526 	{Opt_usrquota, "usrquota"},
1527 	{Opt_prjquota, "prjquota"},
1528 	{Opt_barrier, "barrier=%u"},
1529 	{Opt_barrier, "barrier"},
1530 	{Opt_nobarrier, "nobarrier"},
1531 	{Opt_i_version, "i_version"},
1532 	{Opt_dax, "dax"},
1533 	{Opt_stripe, "stripe=%u"},
1534 	{Opt_delalloc, "delalloc"},
1535 	{Opt_warn_on_error, "warn_on_error"},
1536 	{Opt_nowarn_on_error, "nowarn_on_error"},
1537 	{Opt_lazytime, "lazytime"},
1538 	{Opt_nolazytime, "nolazytime"},
1539 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1540 	{Opt_nodelalloc, "nodelalloc"},
1541 	{Opt_removed, "mblk_io_submit"},
1542 	{Opt_removed, "nomblk_io_submit"},
1543 	{Opt_block_validity, "block_validity"},
1544 	{Opt_noblock_validity, "noblock_validity"},
1545 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1546 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1547 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1548 	{Opt_auto_da_alloc, "auto_da_alloc"},
1549 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1550 	{Opt_dioread_nolock, "dioread_nolock"},
1551 	{Opt_dioread_lock, "dioread_lock"},
1552 	{Opt_discard, "discard"},
1553 	{Opt_nodiscard, "nodiscard"},
1554 	{Opt_init_itable, "init_itable=%u"},
1555 	{Opt_init_itable, "init_itable"},
1556 	{Opt_noinit_itable, "noinit_itable"},
1557 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1558 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1559 	{Opt_nombcache, "nombcache"},
1560 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1561 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1562 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1563 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1564 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1565 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1566 	{Opt_err, NULL},
1567 };
1568 
1569 static ext4_fsblk_t get_sb_block(void **data)
1570 {
1571 	ext4_fsblk_t	sb_block;
1572 	char		*options = (char *) *data;
1573 
1574 	if (!options || strncmp(options, "sb=", 3) != 0)
1575 		return 1;	/* Default location */
1576 
1577 	options += 3;
1578 	/* TODO: use simple_strtoll with >32bit ext4 */
1579 	sb_block = simple_strtoul(options, &options, 0);
1580 	if (*options && *options != ',') {
1581 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1582 		       (char *) *data);
1583 		return 1;
1584 	}
1585 	if (*options == ',')
1586 		options++;
1587 	*data = (void *) options;
1588 
1589 	return sb_block;
1590 }
1591 
1592 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1593 static const char deprecated_msg[] =
1594 	"Mount option \"%s\" will be removed by %s\n"
1595 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1596 
1597 #ifdef CONFIG_QUOTA
1598 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1599 {
1600 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1601 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1602 	int ret = -1;
1603 
1604 	if (sb_any_quota_loaded(sb) && !old_qname) {
1605 		ext4_msg(sb, KERN_ERR,
1606 			"Cannot change journaled "
1607 			"quota options when quota turned on");
1608 		return -1;
1609 	}
1610 	if (ext4_has_feature_quota(sb)) {
1611 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1612 			 "ignored when QUOTA feature is enabled");
1613 		return 1;
1614 	}
1615 	qname = match_strdup(args);
1616 	if (!qname) {
1617 		ext4_msg(sb, KERN_ERR,
1618 			"Not enough memory for storing quotafile name");
1619 		return -1;
1620 	}
1621 	if (old_qname) {
1622 		if (strcmp(old_qname, qname) == 0)
1623 			ret = 1;
1624 		else
1625 			ext4_msg(sb, KERN_ERR,
1626 				 "%s quota file already specified",
1627 				 QTYPE2NAME(qtype));
1628 		goto errout;
1629 	}
1630 	if (strchr(qname, '/')) {
1631 		ext4_msg(sb, KERN_ERR,
1632 			"quotafile must be on filesystem root");
1633 		goto errout;
1634 	}
1635 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1636 	set_opt(sb, QUOTA);
1637 	return 1;
1638 errout:
1639 	kfree(qname);
1640 	return ret;
1641 }
1642 
1643 static int clear_qf_name(struct super_block *sb, int qtype)
1644 {
1645 
1646 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1647 	char *old_qname = get_qf_name(sb, sbi, qtype);
1648 
1649 	if (sb_any_quota_loaded(sb) && old_qname) {
1650 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1651 			" when quota turned on");
1652 		return -1;
1653 	}
1654 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1655 	synchronize_rcu();
1656 	kfree(old_qname);
1657 	return 1;
1658 }
1659 #endif
1660 
1661 #define MOPT_SET	0x0001
1662 #define MOPT_CLEAR	0x0002
1663 #define MOPT_NOSUPPORT	0x0004
1664 #define MOPT_EXPLICIT	0x0008
1665 #define MOPT_CLEAR_ERR	0x0010
1666 #define MOPT_GTE0	0x0020
1667 #ifdef CONFIG_QUOTA
1668 #define MOPT_Q		0
1669 #define MOPT_QFMT	0x0040
1670 #else
1671 #define MOPT_Q		MOPT_NOSUPPORT
1672 #define MOPT_QFMT	MOPT_NOSUPPORT
1673 #endif
1674 #define MOPT_DATAJ	0x0080
1675 #define MOPT_NO_EXT2	0x0100
1676 #define MOPT_NO_EXT3	0x0200
1677 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1678 #define MOPT_STRING	0x0400
1679 
1680 static const struct mount_opts {
1681 	int	token;
1682 	int	mount_opt;
1683 	int	flags;
1684 } ext4_mount_opts[] = {
1685 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1686 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1687 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1688 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1689 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1690 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1691 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1692 	 MOPT_EXT4_ONLY | MOPT_SET},
1693 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1694 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1695 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1696 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1697 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1698 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1699 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1700 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1701 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1702 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1703 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1704 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1705 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1706 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1707 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1708 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1709 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1710 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1711 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1712 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1713 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1714 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1715 	 MOPT_NO_EXT2},
1716 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1717 	 MOPT_NO_EXT2},
1718 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1719 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1720 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1721 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1722 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1723 	{Opt_commit, 0, MOPT_GTE0},
1724 	{Opt_max_batch_time, 0, MOPT_GTE0},
1725 	{Opt_min_batch_time, 0, MOPT_GTE0},
1726 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1727 	{Opt_init_itable, 0, MOPT_GTE0},
1728 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1729 	{Opt_stripe, 0, MOPT_GTE0},
1730 	{Opt_resuid, 0, MOPT_GTE0},
1731 	{Opt_resgid, 0, MOPT_GTE0},
1732 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1733 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1734 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1735 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1736 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1737 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1738 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1739 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1740 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1741 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1742 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1743 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1744 #else
1745 	{Opt_acl, 0, MOPT_NOSUPPORT},
1746 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1747 #endif
1748 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1749 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1750 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1751 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1752 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1753 							MOPT_SET | MOPT_Q},
1754 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1755 							MOPT_SET | MOPT_Q},
1756 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1757 							MOPT_SET | MOPT_Q},
1758 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1759 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1760 							MOPT_CLEAR | MOPT_Q},
1761 	{Opt_usrjquota, 0, MOPT_Q},
1762 	{Opt_grpjquota, 0, MOPT_Q},
1763 	{Opt_offusrjquota, 0, MOPT_Q},
1764 	{Opt_offgrpjquota, 0, MOPT_Q},
1765 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1766 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1767 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1768 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1769 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1770 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1771 	{Opt_err, 0, 0}
1772 };
1773 
1774 #ifdef CONFIG_UNICODE
1775 static const struct ext4_sb_encodings {
1776 	__u16 magic;
1777 	char *name;
1778 	char *version;
1779 } ext4_sb_encoding_map[] = {
1780 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1781 };
1782 
1783 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1784 				 const struct ext4_sb_encodings **encoding,
1785 				 __u16 *flags)
1786 {
1787 	__u16 magic = le16_to_cpu(es->s_encoding);
1788 	int i;
1789 
1790 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1791 		if (magic == ext4_sb_encoding_map[i].magic)
1792 			break;
1793 
1794 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1795 		return -EINVAL;
1796 
1797 	*encoding = &ext4_sb_encoding_map[i];
1798 	*flags = le16_to_cpu(es->s_encoding_flags);
1799 
1800 	return 0;
1801 }
1802 #endif
1803 
1804 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1805 			    substring_t *args, unsigned long *journal_devnum,
1806 			    unsigned int *journal_ioprio, int is_remount)
1807 {
1808 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1809 	const struct mount_opts *m;
1810 	kuid_t uid;
1811 	kgid_t gid;
1812 	int arg = 0;
1813 
1814 #ifdef CONFIG_QUOTA
1815 	if (token == Opt_usrjquota)
1816 		return set_qf_name(sb, USRQUOTA, &args[0]);
1817 	else if (token == Opt_grpjquota)
1818 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1819 	else if (token == Opt_offusrjquota)
1820 		return clear_qf_name(sb, USRQUOTA);
1821 	else if (token == Opt_offgrpjquota)
1822 		return clear_qf_name(sb, GRPQUOTA);
1823 #endif
1824 	switch (token) {
1825 	case Opt_noacl:
1826 	case Opt_nouser_xattr:
1827 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1828 		break;
1829 	case Opt_sb:
1830 		return 1;	/* handled by get_sb_block() */
1831 	case Opt_removed:
1832 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1833 		return 1;
1834 	case Opt_abort:
1835 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1836 		return 1;
1837 	case Opt_i_version:
1838 		sb->s_flags |= SB_I_VERSION;
1839 		return 1;
1840 	case Opt_lazytime:
1841 		sb->s_flags |= SB_LAZYTIME;
1842 		return 1;
1843 	case Opt_nolazytime:
1844 		sb->s_flags &= ~SB_LAZYTIME;
1845 		return 1;
1846 	}
1847 
1848 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1849 		if (token == m->token)
1850 			break;
1851 
1852 	if (m->token == Opt_err) {
1853 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1854 			 "or missing value", opt);
1855 		return -1;
1856 	}
1857 
1858 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1859 		ext4_msg(sb, KERN_ERR,
1860 			 "Mount option \"%s\" incompatible with ext2", opt);
1861 		return -1;
1862 	}
1863 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1864 		ext4_msg(sb, KERN_ERR,
1865 			 "Mount option \"%s\" incompatible with ext3", opt);
1866 		return -1;
1867 	}
1868 
1869 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1870 		return -1;
1871 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1872 		return -1;
1873 	if (m->flags & MOPT_EXPLICIT) {
1874 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1875 			set_opt2(sb, EXPLICIT_DELALLOC);
1876 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1877 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1878 		} else
1879 			return -1;
1880 	}
1881 	if (m->flags & MOPT_CLEAR_ERR)
1882 		clear_opt(sb, ERRORS_MASK);
1883 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1884 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1885 			 "options when quota turned on");
1886 		return -1;
1887 	}
1888 
1889 	if (m->flags & MOPT_NOSUPPORT) {
1890 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1891 	} else if (token == Opt_commit) {
1892 		if (arg == 0)
1893 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1894 		else if (arg > INT_MAX / HZ) {
1895 			ext4_msg(sb, KERN_ERR,
1896 				 "Invalid commit interval %d, "
1897 				 "must be smaller than %d",
1898 				 arg, INT_MAX / HZ);
1899 			return -1;
1900 		}
1901 		sbi->s_commit_interval = HZ * arg;
1902 	} else if (token == Opt_debug_want_extra_isize) {
1903 		sbi->s_want_extra_isize = arg;
1904 	} else if (token == Opt_max_batch_time) {
1905 		sbi->s_max_batch_time = arg;
1906 	} else if (token == Opt_min_batch_time) {
1907 		sbi->s_min_batch_time = arg;
1908 	} else if (token == Opt_inode_readahead_blks) {
1909 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1910 			ext4_msg(sb, KERN_ERR,
1911 				 "EXT4-fs: inode_readahead_blks must be "
1912 				 "0 or a power of 2 smaller than 2^31");
1913 			return -1;
1914 		}
1915 		sbi->s_inode_readahead_blks = arg;
1916 	} else if (token == Opt_init_itable) {
1917 		set_opt(sb, INIT_INODE_TABLE);
1918 		if (!args->from)
1919 			arg = EXT4_DEF_LI_WAIT_MULT;
1920 		sbi->s_li_wait_mult = arg;
1921 	} else if (token == Opt_max_dir_size_kb) {
1922 		sbi->s_max_dir_size_kb = arg;
1923 	} else if (token == Opt_stripe) {
1924 		sbi->s_stripe = arg;
1925 	} else if (token == Opt_resuid) {
1926 		uid = make_kuid(current_user_ns(), arg);
1927 		if (!uid_valid(uid)) {
1928 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1929 			return -1;
1930 		}
1931 		sbi->s_resuid = uid;
1932 	} else if (token == Opt_resgid) {
1933 		gid = make_kgid(current_user_ns(), arg);
1934 		if (!gid_valid(gid)) {
1935 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1936 			return -1;
1937 		}
1938 		sbi->s_resgid = gid;
1939 	} else if (token == Opt_journal_dev) {
1940 		if (is_remount) {
1941 			ext4_msg(sb, KERN_ERR,
1942 				 "Cannot specify journal on remount");
1943 			return -1;
1944 		}
1945 		*journal_devnum = arg;
1946 	} else if (token == Opt_journal_path) {
1947 		char *journal_path;
1948 		struct inode *journal_inode;
1949 		struct path path;
1950 		int error;
1951 
1952 		if (is_remount) {
1953 			ext4_msg(sb, KERN_ERR,
1954 				 "Cannot specify journal on remount");
1955 			return -1;
1956 		}
1957 		journal_path = match_strdup(&args[0]);
1958 		if (!journal_path) {
1959 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1960 				"journal device string");
1961 			return -1;
1962 		}
1963 
1964 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1965 		if (error) {
1966 			ext4_msg(sb, KERN_ERR, "error: could not find "
1967 				"journal device path: error %d", error);
1968 			kfree(journal_path);
1969 			return -1;
1970 		}
1971 
1972 		journal_inode = d_inode(path.dentry);
1973 		if (!S_ISBLK(journal_inode->i_mode)) {
1974 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1975 				"is not a block device", journal_path);
1976 			path_put(&path);
1977 			kfree(journal_path);
1978 			return -1;
1979 		}
1980 
1981 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1982 		path_put(&path);
1983 		kfree(journal_path);
1984 	} else if (token == Opt_journal_ioprio) {
1985 		if (arg > 7) {
1986 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1987 				 " (must be 0-7)");
1988 			return -1;
1989 		}
1990 		*journal_ioprio =
1991 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1992 	} else if (token == Opt_test_dummy_encryption) {
1993 #ifdef CONFIG_FS_ENCRYPTION
1994 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1995 		ext4_msg(sb, KERN_WARNING,
1996 			 "Test dummy encryption mode enabled");
1997 #else
1998 		ext4_msg(sb, KERN_WARNING,
1999 			 "Test dummy encryption mount option ignored");
2000 #endif
2001 	} else if (m->flags & MOPT_DATAJ) {
2002 		if (is_remount) {
2003 			if (!sbi->s_journal)
2004 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
2005 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
2006 				ext4_msg(sb, KERN_ERR,
2007 					 "Cannot change data mode on remount");
2008 				return -1;
2009 			}
2010 		} else {
2011 			clear_opt(sb, DATA_FLAGS);
2012 			sbi->s_mount_opt |= m->mount_opt;
2013 		}
2014 #ifdef CONFIG_QUOTA
2015 	} else if (m->flags & MOPT_QFMT) {
2016 		if (sb_any_quota_loaded(sb) &&
2017 		    sbi->s_jquota_fmt != m->mount_opt) {
2018 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2019 				 "quota options when quota turned on");
2020 			return -1;
2021 		}
2022 		if (ext4_has_feature_quota(sb)) {
2023 			ext4_msg(sb, KERN_INFO,
2024 				 "Quota format mount options ignored "
2025 				 "when QUOTA feature is enabled");
2026 			return 1;
2027 		}
2028 		sbi->s_jquota_fmt = m->mount_opt;
2029 #endif
2030 	} else if (token == Opt_dax) {
2031 #ifdef CONFIG_FS_DAX
2032 		ext4_msg(sb, KERN_WARNING,
2033 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2034 		sbi->s_mount_opt |= m->mount_opt;
2035 #else
2036 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2037 		return -1;
2038 #endif
2039 	} else if (token == Opt_data_err_abort) {
2040 		sbi->s_mount_opt |= m->mount_opt;
2041 	} else if (token == Opt_data_err_ignore) {
2042 		sbi->s_mount_opt &= ~m->mount_opt;
2043 	} else {
2044 		if (!args->from)
2045 			arg = 1;
2046 		if (m->flags & MOPT_CLEAR)
2047 			arg = !arg;
2048 		else if (unlikely(!(m->flags & MOPT_SET))) {
2049 			ext4_msg(sb, KERN_WARNING,
2050 				 "buggy handling of option %s", opt);
2051 			WARN_ON(1);
2052 			return -1;
2053 		}
2054 		if (arg != 0)
2055 			sbi->s_mount_opt |= m->mount_opt;
2056 		else
2057 			sbi->s_mount_opt &= ~m->mount_opt;
2058 	}
2059 	return 1;
2060 }
2061 
2062 static int parse_options(char *options, struct super_block *sb,
2063 			 unsigned long *journal_devnum,
2064 			 unsigned int *journal_ioprio,
2065 			 int is_remount)
2066 {
2067 	struct ext4_sb_info __maybe_unused *sbi = EXT4_SB(sb);
2068 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2069 	substring_t args[MAX_OPT_ARGS];
2070 	int token;
2071 
2072 	if (!options)
2073 		return 1;
2074 
2075 	while ((p = strsep(&options, ",")) != NULL) {
2076 		if (!*p)
2077 			continue;
2078 		/*
2079 		 * Initialize args struct so we know whether arg was
2080 		 * found; some options take optional arguments.
2081 		 */
2082 		args[0].to = args[0].from = NULL;
2083 		token = match_token(p, tokens, args);
2084 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2085 				     journal_ioprio, is_remount) < 0)
2086 			return 0;
2087 	}
2088 #ifdef CONFIG_QUOTA
2089 	/*
2090 	 * We do the test below only for project quotas. 'usrquota' and
2091 	 * 'grpquota' mount options are allowed even without quota feature
2092 	 * to support legacy quotas in quota files.
2093 	 */
2094 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2095 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2096 			 "Cannot enable project quota enforcement.");
2097 		return 0;
2098 	}
2099 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2100 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2101 	if (usr_qf_name || grp_qf_name) {
2102 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2103 			clear_opt(sb, USRQUOTA);
2104 
2105 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2106 			clear_opt(sb, GRPQUOTA);
2107 
2108 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2109 			ext4_msg(sb, KERN_ERR, "old and new quota "
2110 					"format mixing");
2111 			return 0;
2112 		}
2113 
2114 		if (!sbi->s_jquota_fmt) {
2115 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2116 					"not specified");
2117 			return 0;
2118 		}
2119 	}
2120 #endif
2121 	return 1;
2122 }
2123 
2124 static inline void ext4_show_quota_options(struct seq_file *seq,
2125 					   struct super_block *sb)
2126 {
2127 #if defined(CONFIG_QUOTA)
2128 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2129 	char *usr_qf_name, *grp_qf_name;
2130 
2131 	if (sbi->s_jquota_fmt) {
2132 		char *fmtname = "";
2133 
2134 		switch (sbi->s_jquota_fmt) {
2135 		case QFMT_VFS_OLD:
2136 			fmtname = "vfsold";
2137 			break;
2138 		case QFMT_VFS_V0:
2139 			fmtname = "vfsv0";
2140 			break;
2141 		case QFMT_VFS_V1:
2142 			fmtname = "vfsv1";
2143 			break;
2144 		}
2145 		seq_printf(seq, ",jqfmt=%s", fmtname);
2146 	}
2147 
2148 	rcu_read_lock();
2149 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2150 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2151 	if (usr_qf_name)
2152 		seq_show_option(seq, "usrjquota", usr_qf_name);
2153 	if (grp_qf_name)
2154 		seq_show_option(seq, "grpjquota", grp_qf_name);
2155 	rcu_read_unlock();
2156 #endif
2157 }
2158 
2159 static const char *token2str(int token)
2160 {
2161 	const struct match_token *t;
2162 
2163 	for (t = tokens; t->token != Opt_err; t++)
2164 		if (t->token == token && !strchr(t->pattern, '='))
2165 			break;
2166 	return t->pattern;
2167 }
2168 
2169 /*
2170  * Show an option if
2171  *  - it's set to a non-default value OR
2172  *  - if the per-sb default is different from the global default
2173  */
2174 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2175 			      int nodefs)
2176 {
2177 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2178 	struct ext4_super_block *es = sbi->s_es;
2179 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2180 	const struct mount_opts *m;
2181 	char sep = nodefs ? '\n' : ',';
2182 
2183 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2184 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2185 
2186 	if (sbi->s_sb_block != 1)
2187 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2188 
2189 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2190 		int want_set = m->flags & MOPT_SET;
2191 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2192 		    (m->flags & MOPT_CLEAR_ERR))
2193 			continue;
2194 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2195 			continue; /* skip if same as the default */
2196 		if ((want_set &&
2197 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2198 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2199 			continue; /* select Opt_noFoo vs Opt_Foo */
2200 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2201 	}
2202 
2203 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2204 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2205 		SEQ_OPTS_PRINT("resuid=%u",
2206 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2207 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2208 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2209 		SEQ_OPTS_PRINT("resgid=%u",
2210 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2211 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2212 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2213 		SEQ_OPTS_PUTS("errors=remount-ro");
2214 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2215 		SEQ_OPTS_PUTS("errors=continue");
2216 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2217 		SEQ_OPTS_PUTS("errors=panic");
2218 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2219 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2220 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2221 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2222 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2223 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2224 	if (sb->s_flags & SB_I_VERSION)
2225 		SEQ_OPTS_PUTS("i_version");
2226 	if (nodefs || sbi->s_stripe)
2227 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2228 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2229 			(sbi->s_mount_opt ^ def_mount_opt)) {
2230 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2231 			SEQ_OPTS_PUTS("data=journal");
2232 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2233 			SEQ_OPTS_PUTS("data=ordered");
2234 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2235 			SEQ_OPTS_PUTS("data=writeback");
2236 	}
2237 	if (nodefs ||
2238 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2239 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2240 			       sbi->s_inode_readahead_blks);
2241 
2242 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2243 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2244 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2245 	if (nodefs || sbi->s_max_dir_size_kb)
2246 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2247 	if (test_opt(sb, DATA_ERR_ABORT))
2248 		SEQ_OPTS_PUTS("data_err=abort");
2249 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2250 		SEQ_OPTS_PUTS("test_dummy_encryption");
2251 
2252 	ext4_show_quota_options(seq, sb);
2253 	return 0;
2254 }
2255 
2256 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2257 {
2258 	return _ext4_show_options(seq, root->d_sb, 0);
2259 }
2260 
2261 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2262 {
2263 	struct super_block *sb = seq->private;
2264 	int rc;
2265 
2266 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2267 	rc = _ext4_show_options(seq, sb, 1);
2268 	seq_puts(seq, "\n");
2269 	return rc;
2270 }
2271 
2272 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2273 			    int read_only)
2274 {
2275 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2276 	int err = 0;
2277 
2278 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2279 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2280 			 "forcing read-only mode");
2281 		err = -EROFS;
2282 	}
2283 	if (read_only)
2284 		goto done;
2285 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2286 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2287 			 "running e2fsck is recommended");
2288 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2289 		ext4_msg(sb, KERN_WARNING,
2290 			 "warning: mounting fs with errors, "
2291 			 "running e2fsck is recommended");
2292 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2293 		 le16_to_cpu(es->s_mnt_count) >=
2294 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2295 		ext4_msg(sb, KERN_WARNING,
2296 			 "warning: maximal mount count reached, "
2297 			 "running e2fsck is recommended");
2298 	else if (le32_to_cpu(es->s_checkinterval) &&
2299 		 (ext4_get_tstamp(es, s_lastcheck) +
2300 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2301 		ext4_msg(sb, KERN_WARNING,
2302 			 "warning: checktime reached, "
2303 			 "running e2fsck is recommended");
2304 	if (!sbi->s_journal)
2305 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2306 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2307 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2308 	le16_add_cpu(&es->s_mnt_count, 1);
2309 	ext4_update_tstamp(es, s_mtime);
2310 	if (sbi->s_journal)
2311 		ext4_set_feature_journal_needs_recovery(sb);
2312 
2313 	err = ext4_commit_super(sb, 1);
2314 done:
2315 	if (test_opt(sb, DEBUG))
2316 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2317 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2318 			sb->s_blocksize,
2319 			sbi->s_groups_count,
2320 			EXT4_BLOCKS_PER_GROUP(sb),
2321 			EXT4_INODES_PER_GROUP(sb),
2322 			sbi->s_mount_opt, sbi->s_mount_opt2);
2323 
2324 	cleancache_init_fs(sb);
2325 	return err;
2326 }
2327 
2328 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2329 {
2330 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2331 	struct flex_groups *new_groups;
2332 	int size;
2333 
2334 	if (!sbi->s_log_groups_per_flex)
2335 		return 0;
2336 
2337 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2338 	if (size <= sbi->s_flex_groups_allocated)
2339 		return 0;
2340 
2341 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2342 	new_groups = kvzalloc(size, GFP_KERNEL);
2343 	if (!new_groups) {
2344 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2345 			 size / (int) sizeof(struct flex_groups));
2346 		return -ENOMEM;
2347 	}
2348 
2349 	if (sbi->s_flex_groups) {
2350 		memcpy(new_groups, sbi->s_flex_groups,
2351 		       (sbi->s_flex_groups_allocated *
2352 			sizeof(struct flex_groups)));
2353 		kvfree(sbi->s_flex_groups);
2354 	}
2355 	sbi->s_flex_groups = new_groups;
2356 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2357 	return 0;
2358 }
2359 
2360 static int ext4_fill_flex_info(struct super_block *sb)
2361 {
2362 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2363 	struct ext4_group_desc *gdp = NULL;
2364 	ext4_group_t flex_group;
2365 	int i, err;
2366 
2367 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2368 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2369 		sbi->s_log_groups_per_flex = 0;
2370 		return 1;
2371 	}
2372 
2373 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2374 	if (err)
2375 		goto failed;
2376 
2377 	for (i = 0; i < sbi->s_groups_count; i++) {
2378 		gdp = ext4_get_group_desc(sb, i, NULL);
2379 
2380 		flex_group = ext4_flex_group(sbi, i);
2381 		atomic_add(ext4_free_inodes_count(sb, gdp),
2382 			   &sbi->s_flex_groups[flex_group].free_inodes);
2383 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2384 			     &sbi->s_flex_groups[flex_group].free_clusters);
2385 		atomic_add(ext4_used_dirs_count(sb, gdp),
2386 			   &sbi->s_flex_groups[flex_group].used_dirs);
2387 	}
2388 
2389 	return 1;
2390 failed:
2391 	return 0;
2392 }
2393 
2394 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2395 				   struct ext4_group_desc *gdp)
2396 {
2397 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2398 	__u16 crc = 0;
2399 	__le32 le_group = cpu_to_le32(block_group);
2400 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2401 
2402 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2403 		/* Use new metadata_csum algorithm */
2404 		__u32 csum32;
2405 		__u16 dummy_csum = 0;
2406 
2407 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2408 				     sizeof(le_group));
2409 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2410 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2411 				     sizeof(dummy_csum));
2412 		offset += sizeof(dummy_csum);
2413 		if (offset < sbi->s_desc_size)
2414 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2415 					     sbi->s_desc_size - offset);
2416 
2417 		crc = csum32 & 0xFFFF;
2418 		goto out;
2419 	}
2420 
2421 	/* old crc16 code */
2422 	if (!ext4_has_feature_gdt_csum(sb))
2423 		return 0;
2424 
2425 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2426 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2427 	crc = crc16(crc, (__u8 *)gdp, offset);
2428 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2429 	/* for checksum of struct ext4_group_desc do the rest...*/
2430 	if (ext4_has_feature_64bit(sb) &&
2431 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2432 		crc = crc16(crc, (__u8 *)gdp + offset,
2433 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2434 				offset);
2435 
2436 out:
2437 	return cpu_to_le16(crc);
2438 }
2439 
2440 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2441 				struct ext4_group_desc *gdp)
2442 {
2443 	if (ext4_has_group_desc_csum(sb) &&
2444 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2445 		return 0;
2446 
2447 	return 1;
2448 }
2449 
2450 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2451 			      struct ext4_group_desc *gdp)
2452 {
2453 	if (!ext4_has_group_desc_csum(sb))
2454 		return;
2455 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2456 }
2457 
2458 /* Called at mount-time, super-block is locked */
2459 static int ext4_check_descriptors(struct super_block *sb,
2460 				  ext4_fsblk_t sb_block,
2461 				  ext4_group_t *first_not_zeroed)
2462 {
2463 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2464 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2465 	ext4_fsblk_t last_block;
2466 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2467 	ext4_fsblk_t block_bitmap;
2468 	ext4_fsblk_t inode_bitmap;
2469 	ext4_fsblk_t inode_table;
2470 	int flexbg_flag = 0;
2471 	ext4_group_t i, grp = sbi->s_groups_count;
2472 
2473 	if (ext4_has_feature_flex_bg(sb))
2474 		flexbg_flag = 1;
2475 
2476 	ext4_debug("Checking group descriptors");
2477 
2478 	for (i = 0; i < sbi->s_groups_count; i++) {
2479 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2480 
2481 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2482 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2483 		else
2484 			last_block = first_block +
2485 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2486 
2487 		if ((grp == sbi->s_groups_count) &&
2488 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2489 			grp = i;
2490 
2491 		block_bitmap = ext4_block_bitmap(sb, gdp);
2492 		if (block_bitmap == sb_block) {
2493 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2494 				 "Block bitmap for group %u overlaps "
2495 				 "superblock", i);
2496 			if (!sb_rdonly(sb))
2497 				return 0;
2498 		}
2499 		if (block_bitmap >= sb_block + 1 &&
2500 		    block_bitmap <= last_bg_block) {
2501 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2502 				 "Block bitmap for group %u overlaps "
2503 				 "block group descriptors", i);
2504 			if (!sb_rdonly(sb))
2505 				return 0;
2506 		}
2507 		if (block_bitmap < first_block || block_bitmap > last_block) {
2508 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2509 			       "Block bitmap for group %u not in group "
2510 			       "(block %llu)!", i, block_bitmap);
2511 			return 0;
2512 		}
2513 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2514 		if (inode_bitmap == sb_block) {
2515 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2516 				 "Inode bitmap for group %u overlaps "
2517 				 "superblock", i);
2518 			if (!sb_rdonly(sb))
2519 				return 0;
2520 		}
2521 		if (inode_bitmap >= sb_block + 1 &&
2522 		    inode_bitmap <= last_bg_block) {
2523 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2524 				 "Inode bitmap for group %u overlaps "
2525 				 "block group descriptors", i);
2526 			if (!sb_rdonly(sb))
2527 				return 0;
2528 		}
2529 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2530 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2531 			       "Inode bitmap for group %u not in group "
2532 			       "(block %llu)!", i, inode_bitmap);
2533 			return 0;
2534 		}
2535 		inode_table = ext4_inode_table(sb, gdp);
2536 		if (inode_table == sb_block) {
2537 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2538 				 "Inode table for group %u overlaps "
2539 				 "superblock", i);
2540 			if (!sb_rdonly(sb))
2541 				return 0;
2542 		}
2543 		if (inode_table >= sb_block + 1 &&
2544 		    inode_table <= last_bg_block) {
2545 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2546 				 "Inode table for group %u overlaps "
2547 				 "block group descriptors", i);
2548 			if (!sb_rdonly(sb))
2549 				return 0;
2550 		}
2551 		if (inode_table < first_block ||
2552 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2553 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2554 			       "Inode table for group %u not in group "
2555 			       "(block %llu)!", i, inode_table);
2556 			return 0;
2557 		}
2558 		ext4_lock_group(sb, i);
2559 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2560 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2561 				 "Checksum for group %u failed (%u!=%u)",
2562 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2563 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2564 			if (!sb_rdonly(sb)) {
2565 				ext4_unlock_group(sb, i);
2566 				return 0;
2567 			}
2568 		}
2569 		ext4_unlock_group(sb, i);
2570 		if (!flexbg_flag)
2571 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2572 	}
2573 	if (NULL != first_not_zeroed)
2574 		*first_not_zeroed = grp;
2575 	return 1;
2576 }
2577 
2578 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2579  * the superblock) which were deleted from all directories, but held open by
2580  * a process at the time of a crash.  We walk the list and try to delete these
2581  * inodes at recovery time (only with a read-write filesystem).
2582  *
2583  * In order to keep the orphan inode chain consistent during traversal (in
2584  * case of crash during recovery), we link each inode into the superblock
2585  * orphan list_head and handle it the same way as an inode deletion during
2586  * normal operation (which journals the operations for us).
2587  *
2588  * We only do an iget() and an iput() on each inode, which is very safe if we
2589  * accidentally point at an in-use or already deleted inode.  The worst that
2590  * can happen in this case is that we get a "bit already cleared" message from
2591  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2592  * e2fsck was run on this filesystem, and it must have already done the orphan
2593  * inode cleanup for us, so we can safely abort without any further action.
2594  */
2595 static void ext4_orphan_cleanup(struct super_block *sb,
2596 				struct ext4_super_block *es)
2597 {
2598 	unsigned int s_flags = sb->s_flags;
2599 	int ret, nr_orphans = 0, nr_truncates = 0;
2600 #ifdef CONFIG_QUOTA
2601 	int quota_update = 0;
2602 	int i;
2603 #endif
2604 	if (!es->s_last_orphan) {
2605 		jbd_debug(4, "no orphan inodes to clean up\n");
2606 		return;
2607 	}
2608 
2609 	if (bdev_read_only(sb->s_bdev)) {
2610 		ext4_msg(sb, KERN_ERR, "write access "
2611 			"unavailable, skipping orphan cleanup");
2612 		return;
2613 	}
2614 
2615 	/* Check if feature set would not allow a r/w mount */
2616 	if (!ext4_feature_set_ok(sb, 0)) {
2617 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2618 			 "unknown ROCOMPAT features");
2619 		return;
2620 	}
2621 
2622 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2623 		/* don't clear list on RO mount w/ errors */
2624 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2625 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2626 				  "clearing orphan list.\n");
2627 			es->s_last_orphan = 0;
2628 		}
2629 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2630 		return;
2631 	}
2632 
2633 	if (s_flags & SB_RDONLY) {
2634 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2635 		sb->s_flags &= ~SB_RDONLY;
2636 	}
2637 #ifdef CONFIG_QUOTA
2638 	/* Needed for iput() to work correctly and not trash data */
2639 	sb->s_flags |= SB_ACTIVE;
2640 
2641 	/*
2642 	 * Turn on quotas which were not enabled for read-only mounts if
2643 	 * filesystem has quota feature, so that they are updated correctly.
2644 	 */
2645 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2646 		int ret = ext4_enable_quotas(sb);
2647 
2648 		if (!ret)
2649 			quota_update = 1;
2650 		else
2651 			ext4_msg(sb, KERN_ERR,
2652 				"Cannot turn on quotas: error %d", ret);
2653 	}
2654 
2655 	/* Turn on journaled quotas used for old sytle */
2656 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2657 		if (EXT4_SB(sb)->s_qf_names[i]) {
2658 			int ret = ext4_quota_on_mount(sb, i);
2659 
2660 			if (!ret)
2661 				quota_update = 1;
2662 			else
2663 				ext4_msg(sb, KERN_ERR,
2664 					"Cannot turn on journaled "
2665 					"quota: type %d: error %d", i, ret);
2666 		}
2667 	}
2668 #endif
2669 
2670 	while (es->s_last_orphan) {
2671 		struct inode *inode;
2672 
2673 		/*
2674 		 * We may have encountered an error during cleanup; if
2675 		 * so, skip the rest.
2676 		 */
2677 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2678 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2679 			es->s_last_orphan = 0;
2680 			break;
2681 		}
2682 
2683 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2684 		if (IS_ERR(inode)) {
2685 			es->s_last_orphan = 0;
2686 			break;
2687 		}
2688 
2689 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2690 		dquot_initialize(inode);
2691 		if (inode->i_nlink) {
2692 			if (test_opt(sb, DEBUG))
2693 				ext4_msg(sb, KERN_DEBUG,
2694 					"%s: truncating inode %lu to %lld bytes",
2695 					__func__, inode->i_ino, inode->i_size);
2696 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2697 				  inode->i_ino, inode->i_size);
2698 			inode_lock(inode);
2699 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2700 			ret = ext4_truncate(inode);
2701 			if (ret)
2702 				ext4_std_error(inode->i_sb, ret);
2703 			inode_unlock(inode);
2704 			nr_truncates++;
2705 		} else {
2706 			if (test_opt(sb, DEBUG))
2707 				ext4_msg(sb, KERN_DEBUG,
2708 					"%s: deleting unreferenced inode %lu",
2709 					__func__, inode->i_ino);
2710 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2711 				  inode->i_ino);
2712 			nr_orphans++;
2713 		}
2714 		iput(inode);  /* The delete magic happens here! */
2715 	}
2716 
2717 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2718 
2719 	if (nr_orphans)
2720 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2721 		       PLURAL(nr_orphans));
2722 	if (nr_truncates)
2723 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2724 		       PLURAL(nr_truncates));
2725 #ifdef CONFIG_QUOTA
2726 	/* Turn off quotas if they were enabled for orphan cleanup */
2727 	if (quota_update) {
2728 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2729 			if (sb_dqopt(sb)->files[i])
2730 				dquot_quota_off(sb, i);
2731 		}
2732 	}
2733 #endif
2734 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2735 }
2736 
2737 /*
2738  * Maximal extent format file size.
2739  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2740  * extent format containers, within a sector_t, and within i_blocks
2741  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2742  * so that won't be a limiting factor.
2743  *
2744  * However there is other limiting factor. We do store extents in the form
2745  * of starting block and length, hence the resulting length of the extent
2746  * covering maximum file size must fit into on-disk format containers as
2747  * well. Given that length is always by 1 unit bigger than max unit (because
2748  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2749  *
2750  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2751  */
2752 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2753 {
2754 	loff_t res;
2755 	loff_t upper_limit = MAX_LFS_FILESIZE;
2756 
2757 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2758 
2759 	if (!has_huge_files) {
2760 		upper_limit = (1LL << 32) - 1;
2761 
2762 		/* total blocks in file system block size */
2763 		upper_limit >>= (blkbits - 9);
2764 		upper_limit <<= blkbits;
2765 	}
2766 
2767 	/*
2768 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2769 	 * by one fs block, so ee_len can cover the extent of maximum file
2770 	 * size
2771 	 */
2772 	res = (1LL << 32) - 1;
2773 	res <<= blkbits;
2774 
2775 	/* Sanity check against vm- & vfs- imposed limits */
2776 	if (res > upper_limit)
2777 		res = upper_limit;
2778 
2779 	return res;
2780 }
2781 
2782 /*
2783  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2784  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2785  * We need to be 1 filesystem block less than the 2^48 sector limit.
2786  */
2787 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2788 {
2789 	loff_t res = EXT4_NDIR_BLOCKS;
2790 	int meta_blocks;
2791 	loff_t upper_limit;
2792 	/* This is calculated to be the largest file size for a dense, block
2793 	 * mapped file such that the file's total number of 512-byte sectors,
2794 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2795 	 *
2796 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2797 	 * number of 512-byte sectors of the file.
2798 	 */
2799 
2800 	if (!has_huge_files) {
2801 		/*
2802 		 * !has_huge_files or implies that the inode i_block field
2803 		 * represents total file blocks in 2^32 512-byte sectors ==
2804 		 * size of vfs inode i_blocks * 8
2805 		 */
2806 		upper_limit = (1LL << 32) - 1;
2807 
2808 		/* total blocks in file system block size */
2809 		upper_limit >>= (bits - 9);
2810 
2811 	} else {
2812 		/*
2813 		 * We use 48 bit ext4_inode i_blocks
2814 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2815 		 * represent total number of blocks in
2816 		 * file system block size
2817 		 */
2818 		upper_limit = (1LL << 48) - 1;
2819 
2820 	}
2821 
2822 	/* indirect blocks */
2823 	meta_blocks = 1;
2824 	/* double indirect blocks */
2825 	meta_blocks += 1 + (1LL << (bits-2));
2826 	/* tripple indirect blocks */
2827 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2828 
2829 	upper_limit -= meta_blocks;
2830 	upper_limit <<= bits;
2831 
2832 	res += 1LL << (bits-2);
2833 	res += 1LL << (2*(bits-2));
2834 	res += 1LL << (3*(bits-2));
2835 	res <<= bits;
2836 	if (res > upper_limit)
2837 		res = upper_limit;
2838 
2839 	if (res > MAX_LFS_FILESIZE)
2840 		res = MAX_LFS_FILESIZE;
2841 
2842 	return res;
2843 }
2844 
2845 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2846 				   ext4_fsblk_t logical_sb_block, int nr)
2847 {
2848 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2849 	ext4_group_t bg, first_meta_bg;
2850 	int has_super = 0;
2851 
2852 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2853 
2854 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2855 		return logical_sb_block + nr + 1;
2856 	bg = sbi->s_desc_per_block * nr;
2857 	if (ext4_bg_has_super(sb, bg))
2858 		has_super = 1;
2859 
2860 	/*
2861 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2862 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2863 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2864 	 * compensate.
2865 	 */
2866 	if (sb->s_blocksize == 1024 && nr == 0 &&
2867 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2868 		has_super++;
2869 
2870 	return (has_super + ext4_group_first_block_no(sb, bg));
2871 }
2872 
2873 /**
2874  * ext4_get_stripe_size: Get the stripe size.
2875  * @sbi: In memory super block info
2876  *
2877  * If we have specified it via mount option, then
2878  * use the mount option value. If the value specified at mount time is
2879  * greater than the blocks per group use the super block value.
2880  * If the super block value is greater than blocks per group return 0.
2881  * Allocator needs it be less than blocks per group.
2882  *
2883  */
2884 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2885 {
2886 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2887 	unsigned long stripe_width =
2888 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2889 	int ret;
2890 
2891 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2892 		ret = sbi->s_stripe;
2893 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2894 		ret = stripe_width;
2895 	else if (stride && stride <= sbi->s_blocks_per_group)
2896 		ret = stride;
2897 	else
2898 		ret = 0;
2899 
2900 	/*
2901 	 * If the stripe width is 1, this makes no sense and
2902 	 * we set it to 0 to turn off stripe handling code.
2903 	 */
2904 	if (ret <= 1)
2905 		ret = 0;
2906 
2907 	return ret;
2908 }
2909 
2910 /*
2911  * Check whether this filesystem can be mounted based on
2912  * the features present and the RDONLY/RDWR mount requested.
2913  * Returns 1 if this filesystem can be mounted as requested,
2914  * 0 if it cannot be.
2915  */
2916 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2917 {
2918 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2919 		ext4_msg(sb, KERN_ERR,
2920 			"Couldn't mount because of "
2921 			"unsupported optional features (%x)",
2922 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2923 			~EXT4_FEATURE_INCOMPAT_SUPP));
2924 		return 0;
2925 	}
2926 
2927 #ifndef CONFIG_UNICODE
2928 	if (ext4_has_feature_casefold(sb)) {
2929 		ext4_msg(sb, KERN_ERR,
2930 			 "Filesystem with casefold feature cannot be "
2931 			 "mounted without CONFIG_UNICODE");
2932 		return 0;
2933 	}
2934 #endif
2935 
2936 	if (readonly)
2937 		return 1;
2938 
2939 	if (ext4_has_feature_readonly(sb)) {
2940 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2941 		sb->s_flags |= SB_RDONLY;
2942 		return 1;
2943 	}
2944 
2945 	/* Check that feature set is OK for a read-write mount */
2946 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2947 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2948 			 "unsupported optional features (%x)",
2949 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2950 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2951 		return 0;
2952 	}
2953 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2954 		ext4_msg(sb, KERN_ERR,
2955 			 "Can't support bigalloc feature without "
2956 			 "extents feature\n");
2957 		return 0;
2958 	}
2959 
2960 #ifndef CONFIG_QUOTA
2961 	if (ext4_has_feature_quota(sb) && !readonly) {
2962 		ext4_msg(sb, KERN_ERR,
2963 			 "Filesystem with quota feature cannot be mounted RDWR "
2964 			 "without CONFIG_QUOTA");
2965 		return 0;
2966 	}
2967 	if (ext4_has_feature_project(sb) && !readonly) {
2968 		ext4_msg(sb, KERN_ERR,
2969 			 "Filesystem with project quota feature cannot be mounted RDWR "
2970 			 "without CONFIG_QUOTA");
2971 		return 0;
2972 	}
2973 #endif  /* CONFIG_QUOTA */
2974 	return 1;
2975 }
2976 
2977 /*
2978  * This function is called once a day if we have errors logged
2979  * on the file system
2980  */
2981 static void print_daily_error_info(struct timer_list *t)
2982 {
2983 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2984 	struct super_block *sb = sbi->s_sb;
2985 	struct ext4_super_block *es = sbi->s_es;
2986 
2987 	if (es->s_error_count)
2988 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2989 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2990 			 le32_to_cpu(es->s_error_count));
2991 	if (es->s_first_error_time) {
2992 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2993 		       sb->s_id,
2994 		       ext4_get_tstamp(es, s_first_error_time),
2995 		       (int) sizeof(es->s_first_error_func),
2996 		       es->s_first_error_func,
2997 		       le32_to_cpu(es->s_first_error_line));
2998 		if (es->s_first_error_ino)
2999 			printk(KERN_CONT ": inode %u",
3000 			       le32_to_cpu(es->s_first_error_ino));
3001 		if (es->s_first_error_block)
3002 			printk(KERN_CONT ": block %llu", (unsigned long long)
3003 			       le64_to_cpu(es->s_first_error_block));
3004 		printk(KERN_CONT "\n");
3005 	}
3006 	if (es->s_last_error_time) {
3007 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3008 		       sb->s_id,
3009 		       ext4_get_tstamp(es, s_last_error_time),
3010 		       (int) sizeof(es->s_last_error_func),
3011 		       es->s_last_error_func,
3012 		       le32_to_cpu(es->s_last_error_line));
3013 		if (es->s_last_error_ino)
3014 			printk(KERN_CONT ": inode %u",
3015 			       le32_to_cpu(es->s_last_error_ino));
3016 		if (es->s_last_error_block)
3017 			printk(KERN_CONT ": block %llu", (unsigned long long)
3018 			       le64_to_cpu(es->s_last_error_block));
3019 		printk(KERN_CONT "\n");
3020 	}
3021 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3022 }
3023 
3024 /* Find next suitable group and run ext4_init_inode_table */
3025 static int ext4_run_li_request(struct ext4_li_request *elr)
3026 {
3027 	struct ext4_group_desc *gdp = NULL;
3028 	ext4_group_t group, ngroups;
3029 	struct super_block *sb;
3030 	unsigned long timeout = 0;
3031 	int ret = 0;
3032 
3033 	sb = elr->lr_super;
3034 	ngroups = EXT4_SB(sb)->s_groups_count;
3035 
3036 	for (group = elr->lr_next_group; group < ngroups; group++) {
3037 		gdp = ext4_get_group_desc(sb, group, NULL);
3038 		if (!gdp) {
3039 			ret = 1;
3040 			break;
3041 		}
3042 
3043 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3044 			break;
3045 	}
3046 
3047 	if (group >= ngroups)
3048 		ret = 1;
3049 
3050 	if (!ret) {
3051 		timeout = jiffies;
3052 		ret = ext4_init_inode_table(sb, group,
3053 					    elr->lr_timeout ? 0 : 1);
3054 		if (elr->lr_timeout == 0) {
3055 			timeout = (jiffies - timeout) *
3056 				  elr->lr_sbi->s_li_wait_mult;
3057 			elr->lr_timeout = timeout;
3058 		}
3059 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3060 		elr->lr_next_group = group + 1;
3061 	}
3062 	return ret;
3063 }
3064 
3065 /*
3066  * Remove lr_request from the list_request and free the
3067  * request structure. Should be called with li_list_mtx held
3068  */
3069 static void ext4_remove_li_request(struct ext4_li_request *elr)
3070 {
3071 	struct ext4_sb_info *sbi;
3072 
3073 	if (!elr)
3074 		return;
3075 
3076 	sbi = elr->lr_sbi;
3077 
3078 	list_del(&elr->lr_request);
3079 	sbi->s_li_request = NULL;
3080 	kfree(elr);
3081 }
3082 
3083 static void ext4_unregister_li_request(struct super_block *sb)
3084 {
3085 	mutex_lock(&ext4_li_mtx);
3086 	if (!ext4_li_info) {
3087 		mutex_unlock(&ext4_li_mtx);
3088 		return;
3089 	}
3090 
3091 	mutex_lock(&ext4_li_info->li_list_mtx);
3092 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3093 	mutex_unlock(&ext4_li_info->li_list_mtx);
3094 	mutex_unlock(&ext4_li_mtx);
3095 }
3096 
3097 static struct task_struct *ext4_lazyinit_task;
3098 
3099 /*
3100  * This is the function where ext4lazyinit thread lives. It walks
3101  * through the request list searching for next scheduled filesystem.
3102  * When such a fs is found, run the lazy initialization request
3103  * (ext4_rn_li_request) and keep track of the time spend in this
3104  * function. Based on that time we compute next schedule time of
3105  * the request. When walking through the list is complete, compute
3106  * next waking time and put itself into sleep.
3107  */
3108 static int ext4_lazyinit_thread(void *arg)
3109 {
3110 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3111 	struct list_head *pos, *n;
3112 	struct ext4_li_request *elr;
3113 	unsigned long next_wakeup, cur;
3114 
3115 	BUG_ON(NULL == eli);
3116 
3117 cont_thread:
3118 	while (true) {
3119 		next_wakeup = MAX_JIFFY_OFFSET;
3120 
3121 		mutex_lock(&eli->li_list_mtx);
3122 		if (list_empty(&eli->li_request_list)) {
3123 			mutex_unlock(&eli->li_list_mtx);
3124 			goto exit_thread;
3125 		}
3126 		list_for_each_safe(pos, n, &eli->li_request_list) {
3127 			int err = 0;
3128 			int progress = 0;
3129 			elr = list_entry(pos, struct ext4_li_request,
3130 					 lr_request);
3131 
3132 			if (time_before(jiffies, elr->lr_next_sched)) {
3133 				if (time_before(elr->lr_next_sched, next_wakeup))
3134 					next_wakeup = elr->lr_next_sched;
3135 				continue;
3136 			}
3137 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3138 				if (sb_start_write_trylock(elr->lr_super)) {
3139 					progress = 1;
3140 					/*
3141 					 * We hold sb->s_umount, sb can not
3142 					 * be removed from the list, it is
3143 					 * now safe to drop li_list_mtx
3144 					 */
3145 					mutex_unlock(&eli->li_list_mtx);
3146 					err = ext4_run_li_request(elr);
3147 					sb_end_write(elr->lr_super);
3148 					mutex_lock(&eli->li_list_mtx);
3149 					n = pos->next;
3150 				}
3151 				up_read((&elr->lr_super->s_umount));
3152 			}
3153 			/* error, remove the lazy_init job */
3154 			if (err) {
3155 				ext4_remove_li_request(elr);
3156 				continue;
3157 			}
3158 			if (!progress) {
3159 				elr->lr_next_sched = jiffies +
3160 					(prandom_u32()
3161 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3162 			}
3163 			if (time_before(elr->lr_next_sched, next_wakeup))
3164 				next_wakeup = elr->lr_next_sched;
3165 		}
3166 		mutex_unlock(&eli->li_list_mtx);
3167 
3168 		try_to_freeze();
3169 
3170 		cur = jiffies;
3171 		if ((time_after_eq(cur, next_wakeup)) ||
3172 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3173 			cond_resched();
3174 			continue;
3175 		}
3176 
3177 		schedule_timeout_interruptible(next_wakeup - cur);
3178 
3179 		if (kthread_should_stop()) {
3180 			ext4_clear_request_list();
3181 			goto exit_thread;
3182 		}
3183 	}
3184 
3185 exit_thread:
3186 	/*
3187 	 * It looks like the request list is empty, but we need
3188 	 * to check it under the li_list_mtx lock, to prevent any
3189 	 * additions into it, and of course we should lock ext4_li_mtx
3190 	 * to atomically free the list and ext4_li_info, because at
3191 	 * this point another ext4 filesystem could be registering
3192 	 * new one.
3193 	 */
3194 	mutex_lock(&ext4_li_mtx);
3195 	mutex_lock(&eli->li_list_mtx);
3196 	if (!list_empty(&eli->li_request_list)) {
3197 		mutex_unlock(&eli->li_list_mtx);
3198 		mutex_unlock(&ext4_li_mtx);
3199 		goto cont_thread;
3200 	}
3201 	mutex_unlock(&eli->li_list_mtx);
3202 	kfree(ext4_li_info);
3203 	ext4_li_info = NULL;
3204 	mutex_unlock(&ext4_li_mtx);
3205 
3206 	return 0;
3207 }
3208 
3209 static void ext4_clear_request_list(void)
3210 {
3211 	struct list_head *pos, *n;
3212 	struct ext4_li_request *elr;
3213 
3214 	mutex_lock(&ext4_li_info->li_list_mtx);
3215 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3216 		elr = list_entry(pos, struct ext4_li_request,
3217 				 lr_request);
3218 		ext4_remove_li_request(elr);
3219 	}
3220 	mutex_unlock(&ext4_li_info->li_list_mtx);
3221 }
3222 
3223 static int ext4_run_lazyinit_thread(void)
3224 {
3225 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3226 					 ext4_li_info, "ext4lazyinit");
3227 	if (IS_ERR(ext4_lazyinit_task)) {
3228 		int err = PTR_ERR(ext4_lazyinit_task);
3229 		ext4_clear_request_list();
3230 		kfree(ext4_li_info);
3231 		ext4_li_info = NULL;
3232 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3233 				 "initialization thread\n",
3234 				 err);
3235 		return err;
3236 	}
3237 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3238 	return 0;
3239 }
3240 
3241 /*
3242  * Check whether it make sense to run itable init. thread or not.
3243  * If there is at least one uninitialized inode table, return
3244  * corresponding group number, else the loop goes through all
3245  * groups and return total number of groups.
3246  */
3247 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3248 {
3249 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3250 	struct ext4_group_desc *gdp = NULL;
3251 
3252 	if (!ext4_has_group_desc_csum(sb))
3253 		return ngroups;
3254 
3255 	for (group = 0; group < ngroups; group++) {
3256 		gdp = ext4_get_group_desc(sb, group, NULL);
3257 		if (!gdp)
3258 			continue;
3259 
3260 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3261 			break;
3262 	}
3263 
3264 	return group;
3265 }
3266 
3267 static int ext4_li_info_new(void)
3268 {
3269 	struct ext4_lazy_init *eli = NULL;
3270 
3271 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3272 	if (!eli)
3273 		return -ENOMEM;
3274 
3275 	INIT_LIST_HEAD(&eli->li_request_list);
3276 	mutex_init(&eli->li_list_mtx);
3277 
3278 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3279 
3280 	ext4_li_info = eli;
3281 
3282 	return 0;
3283 }
3284 
3285 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3286 					    ext4_group_t start)
3287 {
3288 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3289 	struct ext4_li_request *elr;
3290 
3291 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3292 	if (!elr)
3293 		return NULL;
3294 
3295 	elr->lr_super = sb;
3296 	elr->lr_sbi = sbi;
3297 	elr->lr_next_group = start;
3298 
3299 	/*
3300 	 * Randomize first schedule time of the request to
3301 	 * spread the inode table initialization requests
3302 	 * better.
3303 	 */
3304 	elr->lr_next_sched = jiffies + (prandom_u32() %
3305 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3306 	return elr;
3307 }
3308 
3309 int ext4_register_li_request(struct super_block *sb,
3310 			     ext4_group_t first_not_zeroed)
3311 {
3312 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3313 	struct ext4_li_request *elr = NULL;
3314 	ext4_group_t ngroups = sbi->s_groups_count;
3315 	int ret = 0;
3316 
3317 	mutex_lock(&ext4_li_mtx);
3318 	if (sbi->s_li_request != NULL) {
3319 		/*
3320 		 * Reset timeout so it can be computed again, because
3321 		 * s_li_wait_mult might have changed.
3322 		 */
3323 		sbi->s_li_request->lr_timeout = 0;
3324 		goto out;
3325 	}
3326 
3327 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3328 	    !test_opt(sb, INIT_INODE_TABLE))
3329 		goto out;
3330 
3331 	elr = ext4_li_request_new(sb, first_not_zeroed);
3332 	if (!elr) {
3333 		ret = -ENOMEM;
3334 		goto out;
3335 	}
3336 
3337 	if (NULL == ext4_li_info) {
3338 		ret = ext4_li_info_new();
3339 		if (ret)
3340 			goto out;
3341 	}
3342 
3343 	mutex_lock(&ext4_li_info->li_list_mtx);
3344 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3345 	mutex_unlock(&ext4_li_info->li_list_mtx);
3346 
3347 	sbi->s_li_request = elr;
3348 	/*
3349 	 * set elr to NULL here since it has been inserted to
3350 	 * the request_list and the removal and free of it is
3351 	 * handled by ext4_clear_request_list from now on.
3352 	 */
3353 	elr = NULL;
3354 
3355 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3356 		ret = ext4_run_lazyinit_thread();
3357 		if (ret)
3358 			goto out;
3359 	}
3360 out:
3361 	mutex_unlock(&ext4_li_mtx);
3362 	if (ret)
3363 		kfree(elr);
3364 	return ret;
3365 }
3366 
3367 /*
3368  * We do not need to lock anything since this is called on
3369  * module unload.
3370  */
3371 static void ext4_destroy_lazyinit_thread(void)
3372 {
3373 	/*
3374 	 * If thread exited earlier
3375 	 * there's nothing to be done.
3376 	 */
3377 	if (!ext4_li_info || !ext4_lazyinit_task)
3378 		return;
3379 
3380 	kthread_stop(ext4_lazyinit_task);
3381 }
3382 
3383 static int set_journal_csum_feature_set(struct super_block *sb)
3384 {
3385 	int ret = 1;
3386 	int compat, incompat;
3387 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3388 
3389 	if (ext4_has_metadata_csum(sb)) {
3390 		/* journal checksum v3 */
3391 		compat = 0;
3392 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3393 	} else {
3394 		/* journal checksum v1 */
3395 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3396 		incompat = 0;
3397 	}
3398 
3399 	jbd2_journal_clear_features(sbi->s_journal,
3400 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3401 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3402 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3403 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3404 		ret = jbd2_journal_set_features(sbi->s_journal,
3405 				compat, 0,
3406 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3407 				incompat);
3408 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3409 		ret = jbd2_journal_set_features(sbi->s_journal,
3410 				compat, 0,
3411 				incompat);
3412 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3413 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3414 	} else {
3415 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3416 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3417 	}
3418 
3419 	return ret;
3420 }
3421 
3422 /*
3423  * Note: calculating the overhead so we can be compatible with
3424  * historical BSD practice is quite difficult in the face of
3425  * clusters/bigalloc.  This is because multiple metadata blocks from
3426  * different block group can end up in the same allocation cluster.
3427  * Calculating the exact overhead in the face of clustered allocation
3428  * requires either O(all block bitmaps) in memory or O(number of block
3429  * groups**2) in time.  We will still calculate the superblock for
3430  * older file systems --- and if we come across with a bigalloc file
3431  * system with zero in s_overhead_clusters the estimate will be close to
3432  * correct especially for very large cluster sizes --- but for newer
3433  * file systems, it's better to calculate this figure once at mkfs
3434  * time, and store it in the superblock.  If the superblock value is
3435  * present (even for non-bigalloc file systems), we will use it.
3436  */
3437 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3438 			  char *buf)
3439 {
3440 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3441 	struct ext4_group_desc	*gdp;
3442 	ext4_fsblk_t		first_block, last_block, b;
3443 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3444 	int			s, j, count = 0;
3445 
3446 	if (!ext4_has_feature_bigalloc(sb))
3447 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3448 			sbi->s_itb_per_group + 2);
3449 
3450 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3451 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3452 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3453 	for (i = 0; i < ngroups; i++) {
3454 		gdp = ext4_get_group_desc(sb, i, NULL);
3455 		b = ext4_block_bitmap(sb, gdp);
3456 		if (b >= first_block && b <= last_block) {
3457 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3458 			count++;
3459 		}
3460 		b = ext4_inode_bitmap(sb, gdp);
3461 		if (b >= first_block && b <= last_block) {
3462 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3463 			count++;
3464 		}
3465 		b = ext4_inode_table(sb, gdp);
3466 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3467 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3468 				int c = EXT4_B2C(sbi, b - first_block);
3469 				ext4_set_bit(c, buf);
3470 				count++;
3471 			}
3472 		if (i != grp)
3473 			continue;
3474 		s = 0;
3475 		if (ext4_bg_has_super(sb, grp)) {
3476 			ext4_set_bit(s++, buf);
3477 			count++;
3478 		}
3479 		j = ext4_bg_num_gdb(sb, grp);
3480 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3481 			ext4_error(sb, "Invalid number of block group "
3482 				   "descriptor blocks: %d", j);
3483 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3484 		}
3485 		count += j;
3486 		for (; j > 0; j--)
3487 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3488 	}
3489 	if (!count)
3490 		return 0;
3491 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3492 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3493 }
3494 
3495 /*
3496  * Compute the overhead and stash it in sbi->s_overhead
3497  */
3498 int ext4_calculate_overhead(struct super_block *sb)
3499 {
3500 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3501 	struct ext4_super_block *es = sbi->s_es;
3502 	struct inode *j_inode;
3503 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3504 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3505 	ext4_fsblk_t overhead = 0;
3506 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3507 
3508 	if (!buf)
3509 		return -ENOMEM;
3510 
3511 	/*
3512 	 * Compute the overhead (FS structures).  This is constant
3513 	 * for a given filesystem unless the number of block groups
3514 	 * changes so we cache the previous value until it does.
3515 	 */
3516 
3517 	/*
3518 	 * All of the blocks before first_data_block are overhead
3519 	 */
3520 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3521 
3522 	/*
3523 	 * Add the overhead found in each block group
3524 	 */
3525 	for (i = 0; i < ngroups; i++) {
3526 		int blks;
3527 
3528 		blks = count_overhead(sb, i, buf);
3529 		overhead += blks;
3530 		if (blks)
3531 			memset(buf, 0, PAGE_SIZE);
3532 		cond_resched();
3533 	}
3534 
3535 	/*
3536 	 * Add the internal journal blocks whether the journal has been
3537 	 * loaded or not
3538 	 */
3539 	if (sbi->s_journal && !sbi->journal_bdev)
3540 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3541 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3542 		j_inode = ext4_get_journal_inode(sb, j_inum);
3543 		if (j_inode) {
3544 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3545 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3546 			iput(j_inode);
3547 		} else {
3548 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3549 		}
3550 	}
3551 	sbi->s_overhead = overhead;
3552 	smp_wmb();
3553 	free_page((unsigned long) buf);
3554 	return 0;
3555 }
3556 
3557 static void ext4_clamp_want_extra_isize(struct super_block *sb)
3558 {
3559 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3560 	struct ext4_super_block *es = sbi->s_es;
3561 	unsigned def_extra_isize = sizeof(struct ext4_inode) -
3562 						EXT4_GOOD_OLD_INODE_SIZE;
3563 
3564 	if (sbi->s_inode_size == EXT4_GOOD_OLD_INODE_SIZE) {
3565 		sbi->s_want_extra_isize = 0;
3566 		return;
3567 	}
3568 	if (sbi->s_want_extra_isize < 4) {
3569 		sbi->s_want_extra_isize = def_extra_isize;
3570 		if (ext4_has_feature_extra_isize(sb)) {
3571 			if (sbi->s_want_extra_isize <
3572 			    le16_to_cpu(es->s_want_extra_isize))
3573 				sbi->s_want_extra_isize =
3574 					le16_to_cpu(es->s_want_extra_isize);
3575 			if (sbi->s_want_extra_isize <
3576 			    le16_to_cpu(es->s_min_extra_isize))
3577 				sbi->s_want_extra_isize =
3578 					le16_to_cpu(es->s_min_extra_isize);
3579 		}
3580 	}
3581 	/* Check if enough inode space is available */
3582 	if ((sbi->s_want_extra_isize > sbi->s_inode_size) ||
3583 	    (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3584 							sbi->s_inode_size)) {
3585 		sbi->s_want_extra_isize = def_extra_isize;
3586 		ext4_msg(sb, KERN_INFO,
3587 			 "required extra inode space not available");
3588 	}
3589 }
3590 
3591 static void ext4_set_resv_clusters(struct super_block *sb)
3592 {
3593 	ext4_fsblk_t resv_clusters;
3594 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3595 
3596 	/*
3597 	 * There's no need to reserve anything when we aren't using extents.
3598 	 * The space estimates are exact, there are no unwritten extents,
3599 	 * hole punching doesn't need new metadata... This is needed especially
3600 	 * to keep ext2/3 backward compatibility.
3601 	 */
3602 	if (!ext4_has_feature_extents(sb))
3603 		return;
3604 	/*
3605 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3606 	 * This should cover the situations where we can not afford to run
3607 	 * out of space like for example punch hole, or converting
3608 	 * unwritten extents in delalloc path. In most cases such
3609 	 * allocation would require 1, or 2 blocks, higher numbers are
3610 	 * very rare.
3611 	 */
3612 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3613 			 sbi->s_cluster_bits);
3614 
3615 	do_div(resv_clusters, 50);
3616 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3617 
3618 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3619 }
3620 
3621 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3622 {
3623 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3624 	char *orig_data = kstrdup(data, GFP_KERNEL);
3625 	struct buffer_head *bh;
3626 	struct ext4_super_block *es = NULL;
3627 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3628 	ext4_fsblk_t block;
3629 	ext4_fsblk_t sb_block = get_sb_block(&data);
3630 	ext4_fsblk_t logical_sb_block;
3631 	unsigned long offset = 0;
3632 	unsigned long journal_devnum = 0;
3633 	unsigned long def_mount_opts;
3634 	struct inode *root;
3635 	const char *descr;
3636 	int ret = -ENOMEM;
3637 	int blocksize, clustersize;
3638 	unsigned int db_count;
3639 	unsigned int i;
3640 	int needs_recovery, has_huge_files, has_bigalloc;
3641 	__u64 blocks_count;
3642 	int err = 0;
3643 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3644 	ext4_group_t first_not_zeroed;
3645 
3646 	if ((data && !orig_data) || !sbi)
3647 		goto out_free_base;
3648 
3649 	sbi->s_daxdev = dax_dev;
3650 	sbi->s_blockgroup_lock =
3651 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3652 	if (!sbi->s_blockgroup_lock)
3653 		goto out_free_base;
3654 
3655 	sb->s_fs_info = sbi;
3656 	sbi->s_sb = sb;
3657 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3658 	sbi->s_sb_block = sb_block;
3659 	if (sb->s_bdev->bd_part)
3660 		sbi->s_sectors_written_start =
3661 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3662 
3663 	/* Cleanup superblock name */
3664 	strreplace(sb->s_id, '/', '!');
3665 
3666 	/* -EINVAL is default */
3667 	ret = -EINVAL;
3668 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3669 	if (!blocksize) {
3670 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3671 		goto out_fail;
3672 	}
3673 
3674 	/*
3675 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3676 	 * block sizes.  We need to calculate the offset from buffer start.
3677 	 */
3678 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3679 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3680 		offset = do_div(logical_sb_block, blocksize);
3681 	} else {
3682 		logical_sb_block = sb_block;
3683 	}
3684 
3685 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3686 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3687 		goto out_fail;
3688 	}
3689 	/*
3690 	 * Note: s_es must be initialized as soon as possible because
3691 	 *       some ext4 macro-instructions depend on its value
3692 	 */
3693 	es = (struct ext4_super_block *) (bh->b_data + offset);
3694 	sbi->s_es = es;
3695 	sb->s_magic = le16_to_cpu(es->s_magic);
3696 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3697 		goto cantfind_ext4;
3698 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3699 
3700 	/* Warn if metadata_csum and gdt_csum are both set. */
3701 	if (ext4_has_feature_metadata_csum(sb) &&
3702 	    ext4_has_feature_gdt_csum(sb))
3703 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3704 			     "redundant flags; please run fsck.");
3705 
3706 	/* Check for a known checksum algorithm */
3707 	if (!ext4_verify_csum_type(sb, es)) {
3708 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3709 			 "unknown checksum algorithm.");
3710 		silent = 1;
3711 		goto cantfind_ext4;
3712 	}
3713 
3714 	/* Load the checksum driver */
3715 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3716 	if (IS_ERR(sbi->s_chksum_driver)) {
3717 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3718 		ret = PTR_ERR(sbi->s_chksum_driver);
3719 		sbi->s_chksum_driver = NULL;
3720 		goto failed_mount;
3721 	}
3722 
3723 	/* Check superblock checksum */
3724 	if (!ext4_superblock_csum_verify(sb, es)) {
3725 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3726 			 "invalid superblock checksum.  Run e2fsck?");
3727 		silent = 1;
3728 		ret = -EFSBADCRC;
3729 		goto cantfind_ext4;
3730 	}
3731 
3732 	/* Precompute checksum seed for all metadata */
3733 	if (ext4_has_feature_csum_seed(sb))
3734 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3735 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3736 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3737 					       sizeof(es->s_uuid));
3738 
3739 	/* Set defaults before we parse the mount options */
3740 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3741 	set_opt(sb, INIT_INODE_TABLE);
3742 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3743 		set_opt(sb, DEBUG);
3744 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3745 		set_opt(sb, GRPID);
3746 	if (def_mount_opts & EXT4_DEFM_UID16)
3747 		set_opt(sb, NO_UID32);
3748 	/* xattr user namespace & acls are now defaulted on */
3749 	set_opt(sb, XATTR_USER);
3750 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3751 	set_opt(sb, POSIX_ACL);
3752 #endif
3753 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3754 	if (ext4_has_metadata_csum(sb))
3755 		set_opt(sb, JOURNAL_CHECKSUM);
3756 
3757 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3758 		set_opt(sb, JOURNAL_DATA);
3759 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3760 		set_opt(sb, ORDERED_DATA);
3761 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3762 		set_opt(sb, WRITEBACK_DATA);
3763 
3764 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3765 		set_opt(sb, ERRORS_PANIC);
3766 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3767 		set_opt(sb, ERRORS_CONT);
3768 	else
3769 		set_opt(sb, ERRORS_RO);
3770 	/* block_validity enabled by default; disable with noblock_validity */
3771 	set_opt(sb, BLOCK_VALIDITY);
3772 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3773 		set_opt(sb, DISCARD);
3774 
3775 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3776 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3777 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3778 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3779 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3780 
3781 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3782 		set_opt(sb, BARRIER);
3783 
3784 	/*
3785 	 * enable delayed allocation by default
3786 	 * Use -o nodelalloc to turn it off
3787 	 */
3788 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3789 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3790 		set_opt(sb, DELALLOC);
3791 
3792 	/*
3793 	 * set default s_li_wait_mult for lazyinit, for the case there is
3794 	 * no mount option specified.
3795 	 */
3796 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3797 
3798 	if (sbi->s_es->s_mount_opts[0]) {
3799 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3800 					      sizeof(sbi->s_es->s_mount_opts),
3801 					      GFP_KERNEL);
3802 		if (!s_mount_opts)
3803 			goto failed_mount;
3804 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3805 				   &journal_ioprio, 0)) {
3806 			ext4_msg(sb, KERN_WARNING,
3807 				 "failed to parse options in superblock: %s",
3808 				 s_mount_opts);
3809 		}
3810 		kfree(s_mount_opts);
3811 	}
3812 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3813 	if (!parse_options((char *) data, sb, &journal_devnum,
3814 			   &journal_ioprio, 0))
3815 		goto failed_mount;
3816 
3817 #ifdef CONFIG_UNICODE
3818 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3819 		const struct ext4_sb_encodings *encoding_info;
3820 		struct unicode_map *encoding;
3821 		__u16 encoding_flags;
3822 
3823 		if (ext4_has_feature_encrypt(sb)) {
3824 			ext4_msg(sb, KERN_ERR,
3825 				 "Can't mount with encoding and encryption");
3826 			goto failed_mount;
3827 		}
3828 
3829 		if (ext4_sb_read_encoding(es, &encoding_info,
3830 					  &encoding_flags)) {
3831 			ext4_msg(sb, KERN_ERR,
3832 				 "Encoding requested by superblock is unknown");
3833 			goto failed_mount;
3834 		}
3835 
3836 		encoding = utf8_load(encoding_info->version);
3837 		if (IS_ERR(encoding)) {
3838 			ext4_msg(sb, KERN_ERR,
3839 				 "can't mount with superblock charset: %s-%s "
3840 				 "not supported by the kernel. flags: 0x%x.",
3841 				 encoding_info->name, encoding_info->version,
3842 				 encoding_flags);
3843 			goto failed_mount;
3844 		}
3845 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3846 			 "%s-%s with flags 0x%hx", encoding_info->name,
3847 			 encoding_info->version?:"\b", encoding_flags);
3848 
3849 		sbi->s_encoding = encoding;
3850 		sbi->s_encoding_flags = encoding_flags;
3851 	}
3852 #endif
3853 
3854 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3855 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3856 			    "with data=journal disables delayed "
3857 			    "allocation and O_DIRECT support!\n");
3858 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3859 			ext4_msg(sb, KERN_ERR, "can't mount with "
3860 				 "both data=journal and delalloc");
3861 			goto failed_mount;
3862 		}
3863 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3864 			ext4_msg(sb, KERN_ERR, "can't mount with "
3865 				 "both data=journal and dioread_nolock");
3866 			goto failed_mount;
3867 		}
3868 		if (test_opt(sb, DAX)) {
3869 			ext4_msg(sb, KERN_ERR, "can't mount with "
3870 				 "both data=journal and dax");
3871 			goto failed_mount;
3872 		}
3873 		if (ext4_has_feature_encrypt(sb)) {
3874 			ext4_msg(sb, KERN_WARNING,
3875 				 "encrypted files will use data=ordered "
3876 				 "instead of data journaling mode");
3877 		}
3878 		if (test_opt(sb, DELALLOC))
3879 			clear_opt(sb, DELALLOC);
3880 	} else {
3881 		sb->s_iflags |= SB_I_CGROUPWB;
3882 	}
3883 
3884 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3885 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3886 
3887 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3888 	    (ext4_has_compat_features(sb) ||
3889 	     ext4_has_ro_compat_features(sb) ||
3890 	     ext4_has_incompat_features(sb)))
3891 		ext4_msg(sb, KERN_WARNING,
3892 		       "feature flags set on rev 0 fs, "
3893 		       "running e2fsck is recommended");
3894 
3895 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3896 		set_opt2(sb, HURD_COMPAT);
3897 		if (ext4_has_feature_64bit(sb)) {
3898 			ext4_msg(sb, KERN_ERR,
3899 				 "The Hurd can't support 64-bit file systems");
3900 			goto failed_mount;
3901 		}
3902 
3903 		/*
3904 		 * ea_inode feature uses l_i_version field which is not
3905 		 * available in HURD_COMPAT mode.
3906 		 */
3907 		if (ext4_has_feature_ea_inode(sb)) {
3908 			ext4_msg(sb, KERN_ERR,
3909 				 "ea_inode feature is not supported for Hurd");
3910 			goto failed_mount;
3911 		}
3912 	}
3913 
3914 	if (IS_EXT2_SB(sb)) {
3915 		if (ext2_feature_set_ok(sb))
3916 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3917 				 "using the ext4 subsystem");
3918 		else {
3919 			/*
3920 			 * If we're probing be silent, if this looks like
3921 			 * it's actually an ext[34] filesystem.
3922 			 */
3923 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3924 				goto failed_mount;
3925 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3926 				 "to feature incompatibilities");
3927 			goto failed_mount;
3928 		}
3929 	}
3930 
3931 	if (IS_EXT3_SB(sb)) {
3932 		if (ext3_feature_set_ok(sb))
3933 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3934 				 "using the ext4 subsystem");
3935 		else {
3936 			/*
3937 			 * If we're probing be silent, if this looks like
3938 			 * it's actually an ext4 filesystem.
3939 			 */
3940 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3941 				goto failed_mount;
3942 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3943 				 "to feature incompatibilities");
3944 			goto failed_mount;
3945 		}
3946 	}
3947 
3948 	/*
3949 	 * Check feature flags regardless of the revision level, since we
3950 	 * previously didn't change the revision level when setting the flags,
3951 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3952 	 */
3953 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3954 		goto failed_mount;
3955 
3956 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3957 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3958 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3959 		ext4_msg(sb, KERN_ERR,
3960 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3961 			 blocksize, le32_to_cpu(es->s_log_block_size));
3962 		goto failed_mount;
3963 	}
3964 	if (le32_to_cpu(es->s_log_block_size) >
3965 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3966 		ext4_msg(sb, KERN_ERR,
3967 			 "Invalid log block size: %u",
3968 			 le32_to_cpu(es->s_log_block_size));
3969 		goto failed_mount;
3970 	}
3971 	if (le32_to_cpu(es->s_log_cluster_size) >
3972 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3973 		ext4_msg(sb, KERN_ERR,
3974 			 "Invalid log cluster size: %u",
3975 			 le32_to_cpu(es->s_log_cluster_size));
3976 		goto failed_mount;
3977 	}
3978 
3979 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3980 		ext4_msg(sb, KERN_ERR,
3981 			 "Number of reserved GDT blocks insanely large: %d",
3982 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3983 		goto failed_mount;
3984 	}
3985 
3986 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3987 		if (ext4_has_feature_inline_data(sb)) {
3988 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3989 					" that may contain inline data");
3990 			goto failed_mount;
3991 		}
3992 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3993 			ext4_msg(sb, KERN_ERR,
3994 				"DAX unsupported by block device.");
3995 			goto failed_mount;
3996 		}
3997 	}
3998 
3999 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
4000 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
4001 			 es->s_encryption_level);
4002 		goto failed_mount;
4003 	}
4004 
4005 	if (sb->s_blocksize != blocksize) {
4006 		/* Validate the filesystem blocksize */
4007 		if (!sb_set_blocksize(sb, blocksize)) {
4008 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4009 					blocksize);
4010 			goto failed_mount;
4011 		}
4012 
4013 		brelse(bh);
4014 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4015 		offset = do_div(logical_sb_block, blocksize);
4016 		bh = sb_bread_unmovable(sb, logical_sb_block);
4017 		if (!bh) {
4018 			ext4_msg(sb, KERN_ERR,
4019 			       "Can't read superblock on 2nd try");
4020 			goto failed_mount;
4021 		}
4022 		es = (struct ext4_super_block *)(bh->b_data + offset);
4023 		sbi->s_es = es;
4024 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4025 			ext4_msg(sb, KERN_ERR,
4026 			       "Magic mismatch, very weird!");
4027 			goto failed_mount;
4028 		}
4029 	}
4030 
4031 	has_huge_files = ext4_has_feature_huge_file(sb);
4032 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4033 						      has_huge_files);
4034 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4035 
4036 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4037 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4038 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4039 	} else {
4040 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4041 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4042 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4043 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4044 				 sbi->s_first_ino);
4045 			goto failed_mount;
4046 		}
4047 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4048 		    (!is_power_of_2(sbi->s_inode_size)) ||
4049 		    (sbi->s_inode_size > blocksize)) {
4050 			ext4_msg(sb, KERN_ERR,
4051 			       "unsupported inode size: %d",
4052 			       sbi->s_inode_size);
4053 			goto failed_mount;
4054 		}
4055 		/*
4056 		 * i_atime_extra is the last extra field available for [acm]times in
4057 		 * struct ext4_inode. Checking for that field should suffice to ensure
4058 		 * we have extra space for all three.
4059 		 */
4060 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4061 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4062 			sb->s_time_gran = 1;
4063 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4064 		} else {
4065 			sb->s_time_gran = NSEC_PER_SEC;
4066 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4067 		}
4068 
4069 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4070 	}
4071 
4072 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4073 	if (ext4_has_feature_64bit(sb)) {
4074 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4075 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4076 		    !is_power_of_2(sbi->s_desc_size)) {
4077 			ext4_msg(sb, KERN_ERR,
4078 			       "unsupported descriptor size %lu",
4079 			       sbi->s_desc_size);
4080 			goto failed_mount;
4081 		}
4082 	} else
4083 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4084 
4085 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4086 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4087 
4088 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4089 	if (sbi->s_inodes_per_block == 0)
4090 		goto cantfind_ext4;
4091 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4092 	    sbi->s_inodes_per_group > blocksize * 8) {
4093 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4094 			 sbi->s_blocks_per_group);
4095 		goto failed_mount;
4096 	}
4097 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4098 					sbi->s_inodes_per_block;
4099 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4100 	sbi->s_sbh = bh;
4101 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4102 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4103 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4104 
4105 	for (i = 0; i < 4; i++)
4106 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4107 	sbi->s_def_hash_version = es->s_def_hash_version;
4108 	if (ext4_has_feature_dir_index(sb)) {
4109 		i = le32_to_cpu(es->s_flags);
4110 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4111 			sbi->s_hash_unsigned = 3;
4112 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4113 #ifdef __CHAR_UNSIGNED__
4114 			if (!sb_rdonly(sb))
4115 				es->s_flags |=
4116 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4117 			sbi->s_hash_unsigned = 3;
4118 #else
4119 			if (!sb_rdonly(sb))
4120 				es->s_flags |=
4121 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4122 #endif
4123 		}
4124 	}
4125 
4126 	/* Handle clustersize */
4127 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4128 	has_bigalloc = ext4_has_feature_bigalloc(sb);
4129 	if (has_bigalloc) {
4130 		if (clustersize < blocksize) {
4131 			ext4_msg(sb, KERN_ERR,
4132 				 "cluster size (%d) smaller than "
4133 				 "block size (%d)", clustersize, blocksize);
4134 			goto failed_mount;
4135 		}
4136 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4137 			le32_to_cpu(es->s_log_block_size);
4138 		sbi->s_clusters_per_group =
4139 			le32_to_cpu(es->s_clusters_per_group);
4140 		if (sbi->s_clusters_per_group > blocksize * 8) {
4141 			ext4_msg(sb, KERN_ERR,
4142 				 "#clusters per group too big: %lu",
4143 				 sbi->s_clusters_per_group);
4144 			goto failed_mount;
4145 		}
4146 		if (sbi->s_blocks_per_group !=
4147 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4148 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4149 				 "clusters per group (%lu) inconsistent",
4150 				 sbi->s_blocks_per_group,
4151 				 sbi->s_clusters_per_group);
4152 			goto failed_mount;
4153 		}
4154 	} else {
4155 		if (clustersize != blocksize) {
4156 			ext4_msg(sb, KERN_ERR,
4157 				 "fragment/cluster size (%d) != "
4158 				 "block size (%d)", clustersize, blocksize);
4159 			goto failed_mount;
4160 		}
4161 		if (sbi->s_blocks_per_group > blocksize * 8) {
4162 			ext4_msg(sb, KERN_ERR,
4163 				 "#blocks per group too big: %lu",
4164 				 sbi->s_blocks_per_group);
4165 			goto failed_mount;
4166 		}
4167 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4168 		sbi->s_cluster_bits = 0;
4169 	}
4170 	sbi->s_cluster_ratio = clustersize / blocksize;
4171 
4172 	/* Do we have standard group size of clustersize * 8 blocks ? */
4173 	if (sbi->s_blocks_per_group == clustersize << 3)
4174 		set_opt2(sb, STD_GROUP_SIZE);
4175 
4176 	/*
4177 	 * Test whether we have more sectors than will fit in sector_t,
4178 	 * and whether the max offset is addressable by the page cache.
4179 	 */
4180 	err = generic_check_addressable(sb->s_blocksize_bits,
4181 					ext4_blocks_count(es));
4182 	if (err) {
4183 		ext4_msg(sb, KERN_ERR, "filesystem"
4184 			 " too large to mount safely on this system");
4185 		goto failed_mount;
4186 	}
4187 
4188 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4189 		goto cantfind_ext4;
4190 
4191 	/* check blocks count against device size */
4192 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4193 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4194 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4195 		       "exceeds size of device (%llu blocks)",
4196 		       ext4_blocks_count(es), blocks_count);
4197 		goto failed_mount;
4198 	}
4199 
4200 	/*
4201 	 * It makes no sense for the first data block to be beyond the end
4202 	 * of the filesystem.
4203 	 */
4204 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4205 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4206 			 "block %u is beyond end of filesystem (%llu)",
4207 			 le32_to_cpu(es->s_first_data_block),
4208 			 ext4_blocks_count(es));
4209 		goto failed_mount;
4210 	}
4211 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4212 	    (sbi->s_cluster_ratio == 1)) {
4213 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4214 			 "block is 0 with a 1k block and cluster size");
4215 		goto failed_mount;
4216 	}
4217 
4218 	blocks_count = (ext4_blocks_count(es) -
4219 			le32_to_cpu(es->s_first_data_block) +
4220 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4221 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4222 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4223 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4224 		       "(block count %llu, first data block %u, "
4225 		       "blocks per group %lu)", sbi->s_groups_count,
4226 		       ext4_blocks_count(es),
4227 		       le32_to_cpu(es->s_first_data_block),
4228 		       EXT4_BLOCKS_PER_GROUP(sb));
4229 		goto failed_mount;
4230 	}
4231 	sbi->s_groups_count = blocks_count;
4232 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4233 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4234 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4235 	    le32_to_cpu(es->s_inodes_count)) {
4236 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4237 			 le32_to_cpu(es->s_inodes_count),
4238 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4239 		ret = -EINVAL;
4240 		goto failed_mount;
4241 	}
4242 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4243 		   EXT4_DESC_PER_BLOCK(sb);
4244 	if (ext4_has_feature_meta_bg(sb)) {
4245 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4246 			ext4_msg(sb, KERN_WARNING,
4247 				 "first meta block group too large: %u "
4248 				 "(group descriptor block count %u)",
4249 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4250 			goto failed_mount;
4251 		}
4252 	}
4253 	sbi->s_group_desc = kvmalloc_array(db_count,
4254 					   sizeof(struct buffer_head *),
4255 					   GFP_KERNEL);
4256 	if (sbi->s_group_desc == NULL) {
4257 		ext4_msg(sb, KERN_ERR, "not enough memory");
4258 		ret = -ENOMEM;
4259 		goto failed_mount;
4260 	}
4261 
4262 	bgl_lock_init(sbi->s_blockgroup_lock);
4263 
4264 	/* Pre-read the descriptors into the buffer cache */
4265 	for (i = 0; i < db_count; i++) {
4266 		block = descriptor_loc(sb, logical_sb_block, i);
4267 		sb_breadahead(sb, block);
4268 	}
4269 
4270 	for (i = 0; i < db_count; i++) {
4271 		block = descriptor_loc(sb, logical_sb_block, i);
4272 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4273 		if (!sbi->s_group_desc[i]) {
4274 			ext4_msg(sb, KERN_ERR,
4275 			       "can't read group descriptor %d", i);
4276 			db_count = i;
4277 			goto failed_mount2;
4278 		}
4279 	}
4280 	sbi->s_gdb_count = db_count;
4281 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4282 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4283 		ret = -EFSCORRUPTED;
4284 		goto failed_mount2;
4285 	}
4286 
4287 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4288 
4289 	/* Register extent status tree shrinker */
4290 	if (ext4_es_register_shrinker(sbi))
4291 		goto failed_mount3;
4292 
4293 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4294 	sbi->s_extent_max_zeroout_kb = 32;
4295 
4296 	/*
4297 	 * set up enough so that it can read an inode
4298 	 */
4299 	sb->s_op = &ext4_sops;
4300 	sb->s_export_op = &ext4_export_ops;
4301 	sb->s_xattr = ext4_xattr_handlers;
4302 #ifdef CONFIG_FS_ENCRYPTION
4303 	sb->s_cop = &ext4_cryptops;
4304 #endif
4305 #ifdef CONFIG_FS_VERITY
4306 	sb->s_vop = &ext4_verityops;
4307 #endif
4308 #ifdef CONFIG_QUOTA
4309 	sb->dq_op = &ext4_quota_operations;
4310 	if (ext4_has_feature_quota(sb))
4311 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4312 	else
4313 		sb->s_qcop = &ext4_qctl_operations;
4314 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4315 #endif
4316 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4317 
4318 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4319 	mutex_init(&sbi->s_orphan_lock);
4320 
4321 	sb->s_root = NULL;
4322 
4323 	needs_recovery = (es->s_last_orphan != 0 ||
4324 			  ext4_has_feature_journal_needs_recovery(sb));
4325 
4326 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4327 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4328 			goto failed_mount3a;
4329 
4330 	/*
4331 	 * The first inode we look at is the journal inode.  Don't try
4332 	 * root first: it may be modified in the journal!
4333 	 */
4334 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4335 		err = ext4_load_journal(sb, es, journal_devnum);
4336 		if (err)
4337 			goto failed_mount3a;
4338 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4339 		   ext4_has_feature_journal_needs_recovery(sb)) {
4340 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4341 		       "suppressed and not mounted read-only");
4342 		goto failed_mount_wq;
4343 	} else {
4344 		/* Nojournal mode, all journal mount options are illegal */
4345 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4346 			ext4_msg(sb, KERN_ERR, "can't mount with "
4347 				 "journal_checksum, fs mounted w/o journal");
4348 			goto failed_mount_wq;
4349 		}
4350 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4351 			ext4_msg(sb, KERN_ERR, "can't mount with "
4352 				 "journal_async_commit, fs mounted w/o journal");
4353 			goto failed_mount_wq;
4354 		}
4355 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4356 			ext4_msg(sb, KERN_ERR, "can't mount with "
4357 				 "commit=%lu, fs mounted w/o journal",
4358 				 sbi->s_commit_interval / HZ);
4359 			goto failed_mount_wq;
4360 		}
4361 		if (EXT4_MOUNT_DATA_FLAGS &
4362 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4363 			ext4_msg(sb, KERN_ERR, "can't mount with "
4364 				 "data=, fs mounted w/o journal");
4365 			goto failed_mount_wq;
4366 		}
4367 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4368 		clear_opt(sb, JOURNAL_CHECKSUM);
4369 		clear_opt(sb, DATA_FLAGS);
4370 		sbi->s_journal = NULL;
4371 		needs_recovery = 0;
4372 		goto no_journal;
4373 	}
4374 
4375 	if (ext4_has_feature_64bit(sb) &&
4376 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4377 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4378 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4379 		goto failed_mount_wq;
4380 	}
4381 
4382 	if (!set_journal_csum_feature_set(sb)) {
4383 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4384 			 "feature set");
4385 		goto failed_mount_wq;
4386 	}
4387 
4388 	/* We have now updated the journal if required, so we can
4389 	 * validate the data journaling mode. */
4390 	switch (test_opt(sb, DATA_FLAGS)) {
4391 	case 0:
4392 		/* No mode set, assume a default based on the journal
4393 		 * capabilities: ORDERED_DATA if the journal can
4394 		 * cope, else JOURNAL_DATA
4395 		 */
4396 		if (jbd2_journal_check_available_features
4397 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4398 			set_opt(sb, ORDERED_DATA);
4399 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4400 		} else {
4401 			set_opt(sb, JOURNAL_DATA);
4402 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4403 		}
4404 		break;
4405 
4406 	case EXT4_MOUNT_ORDERED_DATA:
4407 	case EXT4_MOUNT_WRITEBACK_DATA:
4408 		if (!jbd2_journal_check_available_features
4409 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4410 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4411 			       "requested data journaling mode");
4412 			goto failed_mount_wq;
4413 		}
4414 	default:
4415 		break;
4416 	}
4417 
4418 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4419 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4420 		ext4_msg(sb, KERN_ERR, "can't mount with "
4421 			"journal_async_commit in data=ordered mode");
4422 		goto failed_mount_wq;
4423 	}
4424 
4425 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4426 
4427 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4428 
4429 no_journal:
4430 	if (!test_opt(sb, NO_MBCACHE)) {
4431 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4432 		if (!sbi->s_ea_block_cache) {
4433 			ext4_msg(sb, KERN_ERR,
4434 				 "Failed to create ea_block_cache");
4435 			goto failed_mount_wq;
4436 		}
4437 
4438 		if (ext4_has_feature_ea_inode(sb)) {
4439 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4440 			if (!sbi->s_ea_inode_cache) {
4441 				ext4_msg(sb, KERN_ERR,
4442 					 "Failed to create ea_inode_cache");
4443 				goto failed_mount_wq;
4444 			}
4445 		}
4446 	}
4447 
4448 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4449 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4450 		goto failed_mount_wq;
4451 	}
4452 
4453 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4454 	    !ext4_has_feature_encrypt(sb)) {
4455 		ext4_set_feature_encrypt(sb);
4456 		ext4_commit_super(sb, 1);
4457 	}
4458 
4459 	/*
4460 	 * Get the # of file system overhead blocks from the
4461 	 * superblock if present.
4462 	 */
4463 	if (es->s_overhead_clusters)
4464 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4465 	else {
4466 		err = ext4_calculate_overhead(sb);
4467 		if (err)
4468 			goto failed_mount_wq;
4469 	}
4470 
4471 	/*
4472 	 * The maximum number of concurrent works can be high and
4473 	 * concurrency isn't really necessary.  Limit it to 1.
4474 	 */
4475 	EXT4_SB(sb)->rsv_conversion_wq =
4476 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4477 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4478 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4479 		ret = -ENOMEM;
4480 		goto failed_mount4;
4481 	}
4482 
4483 	/*
4484 	 * The jbd2_journal_load will have done any necessary log recovery,
4485 	 * so we can safely mount the rest of the filesystem now.
4486 	 */
4487 
4488 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4489 	if (IS_ERR(root)) {
4490 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4491 		ret = PTR_ERR(root);
4492 		root = NULL;
4493 		goto failed_mount4;
4494 	}
4495 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4496 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4497 		iput(root);
4498 		goto failed_mount4;
4499 	}
4500 
4501 #ifdef CONFIG_UNICODE
4502 	if (sbi->s_encoding)
4503 		sb->s_d_op = &ext4_dentry_ops;
4504 #endif
4505 
4506 	sb->s_root = d_make_root(root);
4507 	if (!sb->s_root) {
4508 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4509 		ret = -ENOMEM;
4510 		goto failed_mount4;
4511 	}
4512 
4513 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4514 	if (ret == -EROFS) {
4515 		sb->s_flags |= SB_RDONLY;
4516 		ret = 0;
4517 	} else if (ret)
4518 		goto failed_mount4a;
4519 
4520 	ext4_clamp_want_extra_isize(sb);
4521 
4522 	ext4_set_resv_clusters(sb);
4523 
4524 	err = ext4_setup_system_zone(sb);
4525 	if (err) {
4526 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4527 			 "zone (%d)", err);
4528 		goto failed_mount4a;
4529 	}
4530 
4531 	ext4_ext_init(sb);
4532 	err = ext4_mb_init(sb);
4533 	if (err) {
4534 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4535 			 err);
4536 		goto failed_mount5;
4537 	}
4538 
4539 	block = ext4_count_free_clusters(sb);
4540 	ext4_free_blocks_count_set(sbi->s_es,
4541 				   EXT4_C2B(sbi, block));
4542 	ext4_superblock_csum_set(sb);
4543 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4544 				  GFP_KERNEL);
4545 	if (!err) {
4546 		unsigned long freei = ext4_count_free_inodes(sb);
4547 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4548 		ext4_superblock_csum_set(sb);
4549 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4550 					  GFP_KERNEL);
4551 	}
4552 	if (!err)
4553 		err = percpu_counter_init(&sbi->s_dirs_counter,
4554 					  ext4_count_dirs(sb), GFP_KERNEL);
4555 	if (!err)
4556 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4557 					  GFP_KERNEL);
4558 	if (!err)
4559 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4560 
4561 	if (err) {
4562 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4563 		goto failed_mount6;
4564 	}
4565 
4566 	if (ext4_has_feature_flex_bg(sb))
4567 		if (!ext4_fill_flex_info(sb)) {
4568 			ext4_msg(sb, KERN_ERR,
4569 			       "unable to initialize "
4570 			       "flex_bg meta info!");
4571 			goto failed_mount6;
4572 		}
4573 
4574 	err = ext4_register_li_request(sb, first_not_zeroed);
4575 	if (err)
4576 		goto failed_mount6;
4577 
4578 	err = ext4_register_sysfs(sb);
4579 	if (err)
4580 		goto failed_mount7;
4581 
4582 #ifdef CONFIG_QUOTA
4583 	/* Enable quota usage during mount. */
4584 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4585 		err = ext4_enable_quotas(sb);
4586 		if (err)
4587 			goto failed_mount8;
4588 	}
4589 #endif  /* CONFIG_QUOTA */
4590 
4591 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4592 	ext4_orphan_cleanup(sb, es);
4593 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4594 	if (needs_recovery) {
4595 		ext4_msg(sb, KERN_INFO, "recovery complete");
4596 		ext4_mark_recovery_complete(sb, es);
4597 	}
4598 	if (EXT4_SB(sb)->s_journal) {
4599 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4600 			descr = " journalled data mode";
4601 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4602 			descr = " ordered data mode";
4603 		else
4604 			descr = " writeback data mode";
4605 	} else
4606 		descr = "out journal";
4607 
4608 	if (test_opt(sb, DISCARD)) {
4609 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4610 		if (!blk_queue_discard(q))
4611 			ext4_msg(sb, KERN_WARNING,
4612 				 "mounting with \"discard\" option, but "
4613 				 "the device does not support discard");
4614 	}
4615 
4616 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4617 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4618 			 "Opts: %.*s%s%s", descr,
4619 			 (int) sizeof(sbi->s_es->s_mount_opts),
4620 			 sbi->s_es->s_mount_opts,
4621 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4622 
4623 	if (es->s_error_count)
4624 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4625 
4626 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4627 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4628 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4629 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4630 
4631 	kfree(orig_data);
4632 	return 0;
4633 
4634 cantfind_ext4:
4635 	if (!silent)
4636 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4637 	goto failed_mount;
4638 
4639 #ifdef CONFIG_QUOTA
4640 failed_mount8:
4641 	ext4_unregister_sysfs(sb);
4642 #endif
4643 failed_mount7:
4644 	ext4_unregister_li_request(sb);
4645 failed_mount6:
4646 	ext4_mb_release(sb);
4647 	if (sbi->s_flex_groups)
4648 		kvfree(sbi->s_flex_groups);
4649 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4650 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4651 	percpu_counter_destroy(&sbi->s_dirs_counter);
4652 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4653 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4654 failed_mount5:
4655 	ext4_ext_release(sb);
4656 	ext4_release_system_zone(sb);
4657 failed_mount4a:
4658 	dput(sb->s_root);
4659 	sb->s_root = NULL;
4660 failed_mount4:
4661 	ext4_msg(sb, KERN_ERR, "mount failed");
4662 	if (EXT4_SB(sb)->rsv_conversion_wq)
4663 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4664 failed_mount_wq:
4665 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4666 	sbi->s_ea_inode_cache = NULL;
4667 
4668 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4669 	sbi->s_ea_block_cache = NULL;
4670 
4671 	if (sbi->s_journal) {
4672 		jbd2_journal_destroy(sbi->s_journal);
4673 		sbi->s_journal = NULL;
4674 	}
4675 failed_mount3a:
4676 	ext4_es_unregister_shrinker(sbi);
4677 failed_mount3:
4678 	del_timer_sync(&sbi->s_err_report);
4679 	if (sbi->s_mmp_tsk)
4680 		kthread_stop(sbi->s_mmp_tsk);
4681 failed_mount2:
4682 	for (i = 0; i < db_count; i++)
4683 		brelse(sbi->s_group_desc[i]);
4684 	kvfree(sbi->s_group_desc);
4685 failed_mount:
4686 	if (sbi->s_chksum_driver)
4687 		crypto_free_shash(sbi->s_chksum_driver);
4688 
4689 #ifdef CONFIG_UNICODE
4690 	utf8_unload(sbi->s_encoding);
4691 #endif
4692 
4693 #ifdef CONFIG_QUOTA
4694 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4695 		kfree(get_qf_name(sb, sbi, i));
4696 #endif
4697 	ext4_blkdev_remove(sbi);
4698 	brelse(bh);
4699 out_fail:
4700 	sb->s_fs_info = NULL;
4701 	kfree(sbi->s_blockgroup_lock);
4702 out_free_base:
4703 	kfree(sbi);
4704 	kfree(orig_data);
4705 	fs_put_dax(dax_dev);
4706 	return err ? err : ret;
4707 }
4708 
4709 /*
4710  * Setup any per-fs journal parameters now.  We'll do this both on
4711  * initial mount, once the journal has been initialised but before we've
4712  * done any recovery; and again on any subsequent remount.
4713  */
4714 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4715 {
4716 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4717 
4718 	journal->j_commit_interval = sbi->s_commit_interval;
4719 	journal->j_min_batch_time = sbi->s_min_batch_time;
4720 	journal->j_max_batch_time = sbi->s_max_batch_time;
4721 
4722 	write_lock(&journal->j_state_lock);
4723 	if (test_opt(sb, BARRIER))
4724 		journal->j_flags |= JBD2_BARRIER;
4725 	else
4726 		journal->j_flags &= ~JBD2_BARRIER;
4727 	if (test_opt(sb, DATA_ERR_ABORT))
4728 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4729 	else
4730 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4731 	write_unlock(&journal->j_state_lock);
4732 }
4733 
4734 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4735 					     unsigned int journal_inum)
4736 {
4737 	struct inode *journal_inode;
4738 
4739 	/*
4740 	 * Test for the existence of a valid inode on disk.  Bad things
4741 	 * happen if we iget() an unused inode, as the subsequent iput()
4742 	 * will try to delete it.
4743 	 */
4744 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4745 	if (IS_ERR(journal_inode)) {
4746 		ext4_msg(sb, KERN_ERR, "no journal found");
4747 		return NULL;
4748 	}
4749 	if (!journal_inode->i_nlink) {
4750 		make_bad_inode(journal_inode);
4751 		iput(journal_inode);
4752 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4753 		return NULL;
4754 	}
4755 
4756 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4757 		  journal_inode, journal_inode->i_size);
4758 	if (!S_ISREG(journal_inode->i_mode)) {
4759 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4760 		iput(journal_inode);
4761 		return NULL;
4762 	}
4763 	return journal_inode;
4764 }
4765 
4766 static journal_t *ext4_get_journal(struct super_block *sb,
4767 				   unsigned int journal_inum)
4768 {
4769 	struct inode *journal_inode;
4770 	journal_t *journal;
4771 
4772 	BUG_ON(!ext4_has_feature_journal(sb));
4773 
4774 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4775 	if (!journal_inode)
4776 		return NULL;
4777 
4778 	journal = jbd2_journal_init_inode(journal_inode);
4779 	if (!journal) {
4780 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4781 		iput(journal_inode);
4782 		return NULL;
4783 	}
4784 	journal->j_private = sb;
4785 	ext4_init_journal_params(sb, journal);
4786 	return journal;
4787 }
4788 
4789 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4790 				       dev_t j_dev)
4791 {
4792 	struct buffer_head *bh;
4793 	journal_t *journal;
4794 	ext4_fsblk_t start;
4795 	ext4_fsblk_t len;
4796 	int hblock, blocksize;
4797 	ext4_fsblk_t sb_block;
4798 	unsigned long offset;
4799 	struct ext4_super_block *es;
4800 	struct block_device *bdev;
4801 
4802 	BUG_ON(!ext4_has_feature_journal(sb));
4803 
4804 	bdev = ext4_blkdev_get(j_dev, sb);
4805 	if (bdev == NULL)
4806 		return NULL;
4807 
4808 	blocksize = sb->s_blocksize;
4809 	hblock = bdev_logical_block_size(bdev);
4810 	if (blocksize < hblock) {
4811 		ext4_msg(sb, KERN_ERR,
4812 			"blocksize too small for journal device");
4813 		goto out_bdev;
4814 	}
4815 
4816 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4817 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4818 	set_blocksize(bdev, blocksize);
4819 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4820 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4821 		       "external journal");
4822 		goto out_bdev;
4823 	}
4824 
4825 	es = (struct ext4_super_block *) (bh->b_data + offset);
4826 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4827 	    !(le32_to_cpu(es->s_feature_incompat) &
4828 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4829 		ext4_msg(sb, KERN_ERR, "external journal has "
4830 					"bad superblock");
4831 		brelse(bh);
4832 		goto out_bdev;
4833 	}
4834 
4835 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4836 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4837 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4838 		ext4_msg(sb, KERN_ERR, "external journal has "
4839 				       "corrupt superblock");
4840 		brelse(bh);
4841 		goto out_bdev;
4842 	}
4843 
4844 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4845 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4846 		brelse(bh);
4847 		goto out_bdev;
4848 	}
4849 
4850 	len = ext4_blocks_count(es);
4851 	start = sb_block + 1;
4852 	brelse(bh);	/* we're done with the superblock */
4853 
4854 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4855 					start, len, blocksize);
4856 	if (!journal) {
4857 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4858 		goto out_bdev;
4859 	}
4860 	journal->j_private = sb;
4861 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4862 	wait_on_buffer(journal->j_sb_buffer);
4863 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4864 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4865 		goto out_journal;
4866 	}
4867 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4868 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4869 					"user (unsupported) - %d",
4870 			be32_to_cpu(journal->j_superblock->s_nr_users));
4871 		goto out_journal;
4872 	}
4873 	EXT4_SB(sb)->journal_bdev = bdev;
4874 	ext4_init_journal_params(sb, journal);
4875 	return journal;
4876 
4877 out_journal:
4878 	jbd2_journal_destroy(journal);
4879 out_bdev:
4880 	ext4_blkdev_put(bdev);
4881 	return NULL;
4882 }
4883 
4884 static int ext4_load_journal(struct super_block *sb,
4885 			     struct ext4_super_block *es,
4886 			     unsigned long journal_devnum)
4887 {
4888 	journal_t *journal;
4889 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4890 	dev_t journal_dev;
4891 	int err = 0;
4892 	int really_read_only;
4893 
4894 	BUG_ON(!ext4_has_feature_journal(sb));
4895 
4896 	if (journal_devnum &&
4897 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4898 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4899 			"numbers have changed");
4900 		journal_dev = new_decode_dev(journal_devnum);
4901 	} else
4902 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4903 
4904 	really_read_only = bdev_read_only(sb->s_bdev);
4905 
4906 	/*
4907 	 * Are we loading a blank journal or performing recovery after a
4908 	 * crash?  For recovery, we need to check in advance whether we
4909 	 * can get read-write access to the device.
4910 	 */
4911 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4912 		if (sb_rdonly(sb)) {
4913 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4914 					"required on readonly filesystem");
4915 			if (really_read_only) {
4916 				ext4_msg(sb, KERN_ERR, "write access "
4917 					"unavailable, cannot proceed "
4918 					"(try mounting with noload)");
4919 				return -EROFS;
4920 			}
4921 			ext4_msg(sb, KERN_INFO, "write access will "
4922 			       "be enabled during recovery");
4923 		}
4924 	}
4925 
4926 	if (journal_inum && journal_dev) {
4927 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4928 		       "and inode journals!");
4929 		return -EINVAL;
4930 	}
4931 
4932 	if (journal_inum) {
4933 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4934 			return -EINVAL;
4935 	} else {
4936 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4937 			return -EINVAL;
4938 	}
4939 
4940 	if (!(journal->j_flags & JBD2_BARRIER))
4941 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4942 
4943 	if (!ext4_has_feature_journal_needs_recovery(sb))
4944 		err = jbd2_journal_wipe(journal, !really_read_only);
4945 	if (!err) {
4946 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4947 		if (save)
4948 			memcpy(save, ((char *) es) +
4949 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4950 		err = jbd2_journal_load(journal);
4951 		if (save)
4952 			memcpy(((char *) es) + EXT4_S_ERR_START,
4953 			       save, EXT4_S_ERR_LEN);
4954 		kfree(save);
4955 	}
4956 
4957 	if (err) {
4958 		ext4_msg(sb, KERN_ERR, "error loading journal");
4959 		jbd2_journal_destroy(journal);
4960 		return err;
4961 	}
4962 
4963 	EXT4_SB(sb)->s_journal = journal;
4964 	ext4_clear_journal_err(sb, es);
4965 
4966 	if (!really_read_only && journal_devnum &&
4967 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4968 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4969 
4970 		/* Make sure we flush the recovery flag to disk. */
4971 		ext4_commit_super(sb, 1);
4972 	}
4973 
4974 	return 0;
4975 }
4976 
4977 static int ext4_commit_super(struct super_block *sb, int sync)
4978 {
4979 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4980 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4981 	int error = 0;
4982 
4983 	if (!sbh || block_device_ejected(sb))
4984 		return error;
4985 
4986 	/*
4987 	 * The superblock bh should be mapped, but it might not be if the
4988 	 * device was hot-removed. Not much we can do but fail the I/O.
4989 	 */
4990 	if (!buffer_mapped(sbh))
4991 		return error;
4992 
4993 	/*
4994 	 * If the file system is mounted read-only, don't update the
4995 	 * superblock write time.  This avoids updating the superblock
4996 	 * write time when we are mounting the root file system
4997 	 * read/only but we need to replay the journal; at that point,
4998 	 * for people who are east of GMT and who make their clock
4999 	 * tick in localtime for Windows bug-for-bug compatibility,
5000 	 * the clock is set in the future, and this will cause e2fsck
5001 	 * to complain and force a full file system check.
5002 	 */
5003 	if (!(sb->s_flags & SB_RDONLY))
5004 		ext4_update_tstamp(es, s_wtime);
5005 	if (sb->s_bdev->bd_part)
5006 		es->s_kbytes_written =
5007 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5008 			    ((part_stat_read(sb->s_bdev->bd_part,
5009 					     sectors[STAT_WRITE]) -
5010 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5011 	else
5012 		es->s_kbytes_written =
5013 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5014 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5015 		ext4_free_blocks_count_set(es,
5016 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5017 				&EXT4_SB(sb)->s_freeclusters_counter)));
5018 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5019 		es->s_free_inodes_count =
5020 			cpu_to_le32(percpu_counter_sum_positive(
5021 				&EXT4_SB(sb)->s_freeinodes_counter));
5022 	BUFFER_TRACE(sbh, "marking dirty");
5023 	ext4_superblock_csum_set(sb);
5024 	if (sync)
5025 		lock_buffer(sbh);
5026 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5027 		/*
5028 		 * Oh, dear.  A previous attempt to write the
5029 		 * superblock failed.  This could happen because the
5030 		 * USB device was yanked out.  Or it could happen to
5031 		 * be a transient write error and maybe the block will
5032 		 * be remapped.  Nothing we can do but to retry the
5033 		 * write and hope for the best.
5034 		 */
5035 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5036 		       "superblock detected");
5037 		clear_buffer_write_io_error(sbh);
5038 		set_buffer_uptodate(sbh);
5039 	}
5040 	mark_buffer_dirty(sbh);
5041 	if (sync) {
5042 		unlock_buffer(sbh);
5043 		error = __sync_dirty_buffer(sbh,
5044 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5045 		if (buffer_write_io_error(sbh)) {
5046 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5047 			       "superblock");
5048 			clear_buffer_write_io_error(sbh);
5049 			set_buffer_uptodate(sbh);
5050 		}
5051 	}
5052 	return error;
5053 }
5054 
5055 /*
5056  * Have we just finished recovery?  If so, and if we are mounting (or
5057  * remounting) the filesystem readonly, then we will end up with a
5058  * consistent fs on disk.  Record that fact.
5059  */
5060 static void ext4_mark_recovery_complete(struct super_block *sb,
5061 					struct ext4_super_block *es)
5062 {
5063 	journal_t *journal = EXT4_SB(sb)->s_journal;
5064 
5065 	if (!ext4_has_feature_journal(sb)) {
5066 		BUG_ON(journal != NULL);
5067 		return;
5068 	}
5069 	jbd2_journal_lock_updates(journal);
5070 	if (jbd2_journal_flush(journal) < 0)
5071 		goto out;
5072 
5073 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5074 		ext4_clear_feature_journal_needs_recovery(sb);
5075 		ext4_commit_super(sb, 1);
5076 	}
5077 
5078 out:
5079 	jbd2_journal_unlock_updates(journal);
5080 }
5081 
5082 /*
5083  * If we are mounting (or read-write remounting) a filesystem whose journal
5084  * has recorded an error from a previous lifetime, move that error to the
5085  * main filesystem now.
5086  */
5087 static void ext4_clear_journal_err(struct super_block *sb,
5088 				   struct ext4_super_block *es)
5089 {
5090 	journal_t *journal;
5091 	int j_errno;
5092 	const char *errstr;
5093 
5094 	BUG_ON(!ext4_has_feature_journal(sb));
5095 
5096 	journal = EXT4_SB(sb)->s_journal;
5097 
5098 	/*
5099 	 * Now check for any error status which may have been recorded in the
5100 	 * journal by a prior ext4_error() or ext4_abort()
5101 	 */
5102 
5103 	j_errno = jbd2_journal_errno(journal);
5104 	if (j_errno) {
5105 		char nbuf[16];
5106 
5107 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5108 		ext4_warning(sb, "Filesystem error recorded "
5109 			     "from previous mount: %s", errstr);
5110 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5111 
5112 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5113 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5114 		ext4_commit_super(sb, 1);
5115 
5116 		jbd2_journal_clear_err(journal);
5117 		jbd2_journal_update_sb_errno(journal);
5118 	}
5119 }
5120 
5121 /*
5122  * Force the running and committing transactions to commit,
5123  * and wait on the commit.
5124  */
5125 int ext4_force_commit(struct super_block *sb)
5126 {
5127 	journal_t *journal;
5128 
5129 	if (sb_rdonly(sb))
5130 		return 0;
5131 
5132 	journal = EXT4_SB(sb)->s_journal;
5133 	return ext4_journal_force_commit(journal);
5134 }
5135 
5136 static int ext4_sync_fs(struct super_block *sb, int wait)
5137 {
5138 	int ret = 0;
5139 	tid_t target;
5140 	bool needs_barrier = false;
5141 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5142 
5143 	if (unlikely(ext4_forced_shutdown(sbi)))
5144 		return 0;
5145 
5146 	trace_ext4_sync_fs(sb, wait);
5147 	flush_workqueue(sbi->rsv_conversion_wq);
5148 	/*
5149 	 * Writeback quota in non-journalled quota case - journalled quota has
5150 	 * no dirty dquots
5151 	 */
5152 	dquot_writeback_dquots(sb, -1);
5153 	/*
5154 	 * Data writeback is possible w/o journal transaction, so barrier must
5155 	 * being sent at the end of the function. But we can skip it if
5156 	 * transaction_commit will do it for us.
5157 	 */
5158 	if (sbi->s_journal) {
5159 		target = jbd2_get_latest_transaction(sbi->s_journal);
5160 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5161 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5162 			needs_barrier = true;
5163 
5164 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5165 			if (wait)
5166 				ret = jbd2_log_wait_commit(sbi->s_journal,
5167 							   target);
5168 		}
5169 	} else if (wait && test_opt(sb, BARRIER))
5170 		needs_barrier = true;
5171 	if (needs_barrier) {
5172 		int err;
5173 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5174 		if (!ret)
5175 			ret = err;
5176 	}
5177 
5178 	return ret;
5179 }
5180 
5181 /*
5182  * LVM calls this function before a (read-only) snapshot is created.  This
5183  * gives us a chance to flush the journal completely and mark the fs clean.
5184  *
5185  * Note that only this function cannot bring a filesystem to be in a clean
5186  * state independently. It relies on upper layer to stop all data & metadata
5187  * modifications.
5188  */
5189 static int ext4_freeze(struct super_block *sb)
5190 {
5191 	int error = 0;
5192 	journal_t *journal;
5193 
5194 	if (sb_rdonly(sb))
5195 		return 0;
5196 
5197 	journal = EXT4_SB(sb)->s_journal;
5198 
5199 	if (journal) {
5200 		/* Now we set up the journal barrier. */
5201 		jbd2_journal_lock_updates(journal);
5202 
5203 		/*
5204 		 * Don't clear the needs_recovery flag if we failed to
5205 		 * flush the journal.
5206 		 */
5207 		error = jbd2_journal_flush(journal);
5208 		if (error < 0)
5209 			goto out;
5210 
5211 		/* Journal blocked and flushed, clear needs_recovery flag. */
5212 		ext4_clear_feature_journal_needs_recovery(sb);
5213 	}
5214 
5215 	error = ext4_commit_super(sb, 1);
5216 out:
5217 	if (journal)
5218 		/* we rely on upper layer to stop further updates */
5219 		jbd2_journal_unlock_updates(journal);
5220 	return error;
5221 }
5222 
5223 /*
5224  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5225  * flag here, even though the filesystem is not technically dirty yet.
5226  */
5227 static int ext4_unfreeze(struct super_block *sb)
5228 {
5229 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5230 		return 0;
5231 
5232 	if (EXT4_SB(sb)->s_journal) {
5233 		/* Reset the needs_recovery flag before the fs is unlocked. */
5234 		ext4_set_feature_journal_needs_recovery(sb);
5235 	}
5236 
5237 	ext4_commit_super(sb, 1);
5238 	return 0;
5239 }
5240 
5241 /*
5242  * Structure to save mount options for ext4_remount's benefit
5243  */
5244 struct ext4_mount_options {
5245 	unsigned long s_mount_opt;
5246 	unsigned long s_mount_opt2;
5247 	kuid_t s_resuid;
5248 	kgid_t s_resgid;
5249 	unsigned long s_commit_interval;
5250 	u32 s_min_batch_time, s_max_batch_time;
5251 #ifdef CONFIG_QUOTA
5252 	int s_jquota_fmt;
5253 	char *s_qf_names[EXT4_MAXQUOTAS];
5254 #endif
5255 };
5256 
5257 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5258 {
5259 	struct ext4_super_block *es;
5260 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5261 	unsigned long old_sb_flags;
5262 	struct ext4_mount_options old_opts;
5263 	int enable_quota = 0;
5264 	ext4_group_t g;
5265 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5266 	int err = 0;
5267 #ifdef CONFIG_QUOTA
5268 	int i, j;
5269 	char *to_free[EXT4_MAXQUOTAS];
5270 #endif
5271 	char *orig_data = kstrdup(data, GFP_KERNEL);
5272 
5273 	if (data && !orig_data)
5274 		return -ENOMEM;
5275 
5276 	/* Store the original options */
5277 	old_sb_flags = sb->s_flags;
5278 	old_opts.s_mount_opt = sbi->s_mount_opt;
5279 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5280 	old_opts.s_resuid = sbi->s_resuid;
5281 	old_opts.s_resgid = sbi->s_resgid;
5282 	old_opts.s_commit_interval = sbi->s_commit_interval;
5283 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5284 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5285 #ifdef CONFIG_QUOTA
5286 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5287 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5288 		if (sbi->s_qf_names[i]) {
5289 			char *qf_name = get_qf_name(sb, sbi, i);
5290 
5291 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5292 			if (!old_opts.s_qf_names[i]) {
5293 				for (j = 0; j < i; j++)
5294 					kfree(old_opts.s_qf_names[j]);
5295 				kfree(orig_data);
5296 				return -ENOMEM;
5297 			}
5298 		} else
5299 			old_opts.s_qf_names[i] = NULL;
5300 #endif
5301 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5302 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5303 
5304 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5305 		err = -EINVAL;
5306 		goto restore_opts;
5307 	}
5308 
5309 	ext4_clamp_want_extra_isize(sb);
5310 
5311 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5312 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5313 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5314 			 "during remount not supported; ignoring");
5315 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5316 	}
5317 
5318 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5319 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5320 			ext4_msg(sb, KERN_ERR, "can't mount with "
5321 				 "both data=journal and delalloc");
5322 			err = -EINVAL;
5323 			goto restore_opts;
5324 		}
5325 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5326 			ext4_msg(sb, KERN_ERR, "can't mount with "
5327 				 "both data=journal and dioread_nolock");
5328 			err = -EINVAL;
5329 			goto restore_opts;
5330 		}
5331 		if (test_opt(sb, DAX)) {
5332 			ext4_msg(sb, KERN_ERR, "can't mount with "
5333 				 "both data=journal and dax");
5334 			err = -EINVAL;
5335 			goto restore_opts;
5336 		}
5337 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5338 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5339 			ext4_msg(sb, KERN_ERR, "can't mount with "
5340 				"journal_async_commit in data=ordered mode");
5341 			err = -EINVAL;
5342 			goto restore_opts;
5343 		}
5344 	}
5345 
5346 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5347 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5348 		err = -EINVAL;
5349 		goto restore_opts;
5350 	}
5351 
5352 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5353 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5354 			"dax flag with busy inodes while remounting");
5355 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5356 	}
5357 
5358 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5359 		ext4_abort(sb, "Abort forced by user");
5360 
5361 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5362 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5363 
5364 	es = sbi->s_es;
5365 
5366 	if (sbi->s_journal) {
5367 		ext4_init_journal_params(sb, sbi->s_journal);
5368 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5369 	}
5370 
5371 	if (*flags & SB_LAZYTIME)
5372 		sb->s_flags |= SB_LAZYTIME;
5373 
5374 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5375 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5376 			err = -EROFS;
5377 			goto restore_opts;
5378 		}
5379 
5380 		if (*flags & SB_RDONLY) {
5381 			err = sync_filesystem(sb);
5382 			if (err < 0)
5383 				goto restore_opts;
5384 			err = dquot_suspend(sb, -1);
5385 			if (err < 0)
5386 				goto restore_opts;
5387 
5388 			/*
5389 			 * First of all, the unconditional stuff we have to do
5390 			 * to disable replay of the journal when we next remount
5391 			 */
5392 			sb->s_flags |= SB_RDONLY;
5393 
5394 			/*
5395 			 * OK, test if we are remounting a valid rw partition
5396 			 * readonly, and if so set the rdonly flag and then
5397 			 * mark the partition as valid again.
5398 			 */
5399 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5400 			    (sbi->s_mount_state & EXT4_VALID_FS))
5401 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5402 
5403 			if (sbi->s_journal)
5404 				ext4_mark_recovery_complete(sb, es);
5405 			if (sbi->s_mmp_tsk)
5406 				kthread_stop(sbi->s_mmp_tsk);
5407 		} else {
5408 			/* Make sure we can mount this feature set readwrite */
5409 			if (ext4_has_feature_readonly(sb) ||
5410 			    !ext4_feature_set_ok(sb, 0)) {
5411 				err = -EROFS;
5412 				goto restore_opts;
5413 			}
5414 			/*
5415 			 * Make sure the group descriptor checksums
5416 			 * are sane.  If they aren't, refuse to remount r/w.
5417 			 */
5418 			for (g = 0; g < sbi->s_groups_count; g++) {
5419 				struct ext4_group_desc *gdp =
5420 					ext4_get_group_desc(sb, g, NULL);
5421 
5422 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5423 					ext4_msg(sb, KERN_ERR,
5424 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5425 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5426 					       le16_to_cpu(gdp->bg_checksum));
5427 					err = -EFSBADCRC;
5428 					goto restore_opts;
5429 				}
5430 			}
5431 
5432 			/*
5433 			 * If we have an unprocessed orphan list hanging
5434 			 * around from a previously readonly bdev mount,
5435 			 * require a full umount/remount for now.
5436 			 */
5437 			if (es->s_last_orphan) {
5438 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5439 				       "remount RDWR because of unprocessed "
5440 				       "orphan inode list.  Please "
5441 				       "umount/remount instead");
5442 				err = -EINVAL;
5443 				goto restore_opts;
5444 			}
5445 
5446 			/*
5447 			 * Mounting a RDONLY partition read-write, so reread
5448 			 * and store the current valid flag.  (It may have
5449 			 * been changed by e2fsck since we originally mounted
5450 			 * the partition.)
5451 			 */
5452 			if (sbi->s_journal)
5453 				ext4_clear_journal_err(sb, es);
5454 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5455 
5456 			err = ext4_setup_super(sb, es, 0);
5457 			if (err)
5458 				goto restore_opts;
5459 
5460 			sb->s_flags &= ~SB_RDONLY;
5461 			if (ext4_has_feature_mmp(sb))
5462 				if (ext4_multi_mount_protect(sb,
5463 						le64_to_cpu(es->s_mmp_block))) {
5464 					err = -EROFS;
5465 					goto restore_opts;
5466 				}
5467 			enable_quota = 1;
5468 		}
5469 	}
5470 
5471 	/*
5472 	 * Reinitialize lazy itable initialization thread based on
5473 	 * current settings
5474 	 */
5475 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5476 		ext4_unregister_li_request(sb);
5477 	else {
5478 		ext4_group_t first_not_zeroed;
5479 		first_not_zeroed = ext4_has_uninit_itable(sb);
5480 		ext4_register_li_request(sb, first_not_zeroed);
5481 	}
5482 
5483 	ext4_setup_system_zone(sb);
5484 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5485 		err = ext4_commit_super(sb, 1);
5486 		if (err)
5487 			goto restore_opts;
5488 	}
5489 
5490 #ifdef CONFIG_QUOTA
5491 	/* Release old quota file names */
5492 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5493 		kfree(old_opts.s_qf_names[i]);
5494 	if (enable_quota) {
5495 		if (sb_any_quota_suspended(sb))
5496 			dquot_resume(sb, -1);
5497 		else if (ext4_has_feature_quota(sb)) {
5498 			err = ext4_enable_quotas(sb);
5499 			if (err)
5500 				goto restore_opts;
5501 		}
5502 	}
5503 #endif
5504 
5505 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5506 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5507 	kfree(orig_data);
5508 	return 0;
5509 
5510 restore_opts:
5511 	sb->s_flags = old_sb_flags;
5512 	sbi->s_mount_opt = old_opts.s_mount_opt;
5513 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5514 	sbi->s_resuid = old_opts.s_resuid;
5515 	sbi->s_resgid = old_opts.s_resgid;
5516 	sbi->s_commit_interval = old_opts.s_commit_interval;
5517 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5518 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5519 #ifdef CONFIG_QUOTA
5520 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5521 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5522 		to_free[i] = get_qf_name(sb, sbi, i);
5523 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5524 	}
5525 	synchronize_rcu();
5526 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5527 		kfree(to_free[i]);
5528 #endif
5529 	kfree(orig_data);
5530 	return err;
5531 }
5532 
5533 #ifdef CONFIG_QUOTA
5534 static int ext4_statfs_project(struct super_block *sb,
5535 			       kprojid_t projid, struct kstatfs *buf)
5536 {
5537 	struct kqid qid;
5538 	struct dquot *dquot;
5539 	u64 limit;
5540 	u64 curblock;
5541 
5542 	qid = make_kqid_projid(projid);
5543 	dquot = dqget(sb, qid);
5544 	if (IS_ERR(dquot))
5545 		return PTR_ERR(dquot);
5546 	spin_lock(&dquot->dq_dqb_lock);
5547 
5548 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5549 		 dquot->dq_dqb.dqb_bsoftlimit :
5550 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5551 	if (limit && buf->f_blocks > limit) {
5552 		curblock = (dquot->dq_dqb.dqb_curspace +
5553 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5554 		buf->f_blocks = limit;
5555 		buf->f_bfree = buf->f_bavail =
5556 			(buf->f_blocks > curblock) ?
5557 			 (buf->f_blocks - curblock) : 0;
5558 	}
5559 
5560 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5561 		dquot->dq_dqb.dqb_isoftlimit :
5562 		dquot->dq_dqb.dqb_ihardlimit;
5563 	if (limit && buf->f_files > limit) {
5564 		buf->f_files = limit;
5565 		buf->f_ffree =
5566 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5567 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5568 	}
5569 
5570 	spin_unlock(&dquot->dq_dqb_lock);
5571 	dqput(dquot);
5572 	return 0;
5573 }
5574 #endif
5575 
5576 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5577 {
5578 	struct super_block *sb = dentry->d_sb;
5579 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5580 	struct ext4_super_block *es = sbi->s_es;
5581 	ext4_fsblk_t overhead = 0, resv_blocks;
5582 	u64 fsid;
5583 	s64 bfree;
5584 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5585 
5586 	if (!test_opt(sb, MINIX_DF))
5587 		overhead = sbi->s_overhead;
5588 
5589 	buf->f_type = EXT4_SUPER_MAGIC;
5590 	buf->f_bsize = sb->s_blocksize;
5591 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5592 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5593 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5594 	/* prevent underflow in case that few free space is available */
5595 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5596 	buf->f_bavail = buf->f_bfree -
5597 			(ext4_r_blocks_count(es) + resv_blocks);
5598 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5599 		buf->f_bavail = 0;
5600 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5601 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5602 	buf->f_namelen = EXT4_NAME_LEN;
5603 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5604 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5605 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5606 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5607 
5608 #ifdef CONFIG_QUOTA
5609 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5610 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5611 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5612 #endif
5613 	return 0;
5614 }
5615 
5616 
5617 #ifdef CONFIG_QUOTA
5618 
5619 /*
5620  * Helper functions so that transaction is started before we acquire dqio_sem
5621  * to keep correct lock ordering of transaction > dqio_sem
5622  */
5623 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5624 {
5625 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5626 }
5627 
5628 static int ext4_write_dquot(struct dquot *dquot)
5629 {
5630 	int ret, err;
5631 	handle_t *handle;
5632 	struct inode *inode;
5633 
5634 	inode = dquot_to_inode(dquot);
5635 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5636 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5637 	if (IS_ERR(handle))
5638 		return PTR_ERR(handle);
5639 	ret = dquot_commit(dquot);
5640 	err = ext4_journal_stop(handle);
5641 	if (!ret)
5642 		ret = err;
5643 	return ret;
5644 }
5645 
5646 static int ext4_acquire_dquot(struct dquot *dquot)
5647 {
5648 	int ret, err;
5649 	handle_t *handle;
5650 
5651 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5652 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5653 	if (IS_ERR(handle))
5654 		return PTR_ERR(handle);
5655 	ret = dquot_acquire(dquot);
5656 	err = ext4_journal_stop(handle);
5657 	if (!ret)
5658 		ret = err;
5659 	return ret;
5660 }
5661 
5662 static int ext4_release_dquot(struct dquot *dquot)
5663 {
5664 	int ret, err;
5665 	handle_t *handle;
5666 
5667 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5668 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5669 	if (IS_ERR(handle)) {
5670 		/* Release dquot anyway to avoid endless cycle in dqput() */
5671 		dquot_release(dquot);
5672 		return PTR_ERR(handle);
5673 	}
5674 	ret = dquot_release(dquot);
5675 	err = ext4_journal_stop(handle);
5676 	if (!ret)
5677 		ret = err;
5678 	return ret;
5679 }
5680 
5681 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5682 {
5683 	struct super_block *sb = dquot->dq_sb;
5684 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5685 
5686 	/* Are we journaling quotas? */
5687 	if (ext4_has_feature_quota(sb) ||
5688 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5689 		dquot_mark_dquot_dirty(dquot);
5690 		return ext4_write_dquot(dquot);
5691 	} else {
5692 		return dquot_mark_dquot_dirty(dquot);
5693 	}
5694 }
5695 
5696 static int ext4_write_info(struct super_block *sb, int type)
5697 {
5698 	int ret, err;
5699 	handle_t *handle;
5700 
5701 	/* Data block + inode block */
5702 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5703 	if (IS_ERR(handle))
5704 		return PTR_ERR(handle);
5705 	ret = dquot_commit_info(sb, type);
5706 	err = ext4_journal_stop(handle);
5707 	if (!ret)
5708 		ret = err;
5709 	return ret;
5710 }
5711 
5712 /*
5713  * Turn on quotas during mount time - we need to find
5714  * the quota file and such...
5715  */
5716 static int ext4_quota_on_mount(struct super_block *sb, int type)
5717 {
5718 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5719 					EXT4_SB(sb)->s_jquota_fmt, type);
5720 }
5721 
5722 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5723 {
5724 	struct ext4_inode_info *ei = EXT4_I(inode);
5725 
5726 	/* The first argument of lockdep_set_subclass has to be
5727 	 * *exactly* the same as the argument to init_rwsem() --- in
5728 	 * this case, in init_once() --- or lockdep gets unhappy
5729 	 * because the name of the lock is set using the
5730 	 * stringification of the argument to init_rwsem().
5731 	 */
5732 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5733 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5734 }
5735 
5736 /*
5737  * Standard function to be called on quota_on
5738  */
5739 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5740 			 const struct path *path)
5741 {
5742 	int err;
5743 
5744 	if (!test_opt(sb, QUOTA))
5745 		return -EINVAL;
5746 
5747 	/* Quotafile not on the same filesystem? */
5748 	if (path->dentry->d_sb != sb)
5749 		return -EXDEV;
5750 	/* Journaling quota? */
5751 	if (EXT4_SB(sb)->s_qf_names[type]) {
5752 		/* Quotafile not in fs root? */
5753 		if (path->dentry->d_parent != sb->s_root)
5754 			ext4_msg(sb, KERN_WARNING,
5755 				"Quota file not on filesystem root. "
5756 				"Journaled quota will not work");
5757 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5758 	} else {
5759 		/*
5760 		 * Clear the flag just in case mount options changed since
5761 		 * last time.
5762 		 */
5763 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5764 	}
5765 
5766 	/*
5767 	 * When we journal data on quota file, we have to flush journal to see
5768 	 * all updates to the file when we bypass pagecache...
5769 	 */
5770 	if (EXT4_SB(sb)->s_journal &&
5771 	    ext4_should_journal_data(d_inode(path->dentry))) {
5772 		/*
5773 		 * We don't need to lock updates but journal_flush() could
5774 		 * otherwise be livelocked...
5775 		 */
5776 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5777 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5778 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5779 		if (err)
5780 			return err;
5781 	}
5782 
5783 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5784 	err = dquot_quota_on(sb, type, format_id, path);
5785 	if (err) {
5786 		lockdep_set_quota_inode(path->dentry->d_inode,
5787 					     I_DATA_SEM_NORMAL);
5788 	} else {
5789 		struct inode *inode = d_inode(path->dentry);
5790 		handle_t *handle;
5791 
5792 		/*
5793 		 * Set inode flags to prevent userspace from messing with quota
5794 		 * files. If this fails, we return success anyway since quotas
5795 		 * are already enabled and this is not a hard failure.
5796 		 */
5797 		inode_lock(inode);
5798 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5799 		if (IS_ERR(handle))
5800 			goto unlock_inode;
5801 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5802 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5803 				S_NOATIME | S_IMMUTABLE);
5804 		ext4_mark_inode_dirty(handle, inode);
5805 		ext4_journal_stop(handle);
5806 	unlock_inode:
5807 		inode_unlock(inode);
5808 	}
5809 	return err;
5810 }
5811 
5812 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5813 			     unsigned int flags)
5814 {
5815 	int err;
5816 	struct inode *qf_inode;
5817 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5818 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5819 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5820 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5821 	};
5822 
5823 	BUG_ON(!ext4_has_feature_quota(sb));
5824 
5825 	if (!qf_inums[type])
5826 		return -EPERM;
5827 
5828 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5829 	if (IS_ERR(qf_inode)) {
5830 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5831 		return PTR_ERR(qf_inode);
5832 	}
5833 
5834 	/* Don't account quota for quota files to avoid recursion */
5835 	qf_inode->i_flags |= S_NOQUOTA;
5836 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5837 	err = dquot_load_quota_inode(qf_inode, type, format_id, flags);
5838 	if (err)
5839 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5840 	iput(qf_inode);
5841 
5842 	return err;
5843 }
5844 
5845 /* Enable usage tracking for all quota types. */
5846 static int ext4_enable_quotas(struct super_block *sb)
5847 {
5848 	int type, err = 0;
5849 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5850 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5851 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5852 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5853 	};
5854 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5855 		test_opt(sb, USRQUOTA),
5856 		test_opt(sb, GRPQUOTA),
5857 		test_opt(sb, PRJQUOTA),
5858 	};
5859 
5860 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5861 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5862 		if (qf_inums[type]) {
5863 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5864 				DQUOT_USAGE_ENABLED |
5865 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5866 			if (err) {
5867 				ext4_warning(sb,
5868 					"Failed to enable quota tracking "
5869 					"(type=%d, err=%d). Please run "
5870 					"e2fsck to fix.", type, err);
5871 				for (type--; type >= 0; type--)
5872 					dquot_quota_off(sb, type);
5873 
5874 				return err;
5875 			}
5876 		}
5877 	}
5878 	return 0;
5879 }
5880 
5881 static int ext4_quota_off(struct super_block *sb, int type)
5882 {
5883 	struct inode *inode = sb_dqopt(sb)->files[type];
5884 	handle_t *handle;
5885 	int err;
5886 
5887 	/* Force all delayed allocation blocks to be allocated.
5888 	 * Caller already holds s_umount sem */
5889 	if (test_opt(sb, DELALLOC))
5890 		sync_filesystem(sb);
5891 
5892 	if (!inode || !igrab(inode))
5893 		goto out;
5894 
5895 	err = dquot_quota_off(sb, type);
5896 	if (err || ext4_has_feature_quota(sb))
5897 		goto out_put;
5898 
5899 	inode_lock(inode);
5900 	/*
5901 	 * Update modification times of quota files when userspace can
5902 	 * start looking at them. If we fail, we return success anyway since
5903 	 * this is not a hard failure and quotas are already disabled.
5904 	 */
5905 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5906 	if (IS_ERR(handle))
5907 		goto out_unlock;
5908 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5909 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5910 	inode->i_mtime = inode->i_ctime = current_time(inode);
5911 	ext4_mark_inode_dirty(handle, inode);
5912 	ext4_journal_stop(handle);
5913 out_unlock:
5914 	inode_unlock(inode);
5915 out_put:
5916 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5917 	iput(inode);
5918 	return err;
5919 out:
5920 	return dquot_quota_off(sb, type);
5921 }
5922 
5923 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5924  * acquiring the locks... As quota files are never truncated and quota code
5925  * itself serializes the operations (and no one else should touch the files)
5926  * we don't have to be afraid of races */
5927 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5928 			       size_t len, loff_t off)
5929 {
5930 	struct inode *inode = sb_dqopt(sb)->files[type];
5931 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5932 	int offset = off & (sb->s_blocksize - 1);
5933 	int tocopy;
5934 	size_t toread;
5935 	struct buffer_head *bh;
5936 	loff_t i_size = i_size_read(inode);
5937 
5938 	if (off > i_size)
5939 		return 0;
5940 	if (off+len > i_size)
5941 		len = i_size-off;
5942 	toread = len;
5943 	while (toread > 0) {
5944 		tocopy = sb->s_blocksize - offset < toread ?
5945 				sb->s_blocksize - offset : toread;
5946 		bh = ext4_bread(NULL, inode, blk, 0);
5947 		if (IS_ERR(bh))
5948 			return PTR_ERR(bh);
5949 		if (!bh)	/* A hole? */
5950 			memset(data, 0, tocopy);
5951 		else
5952 			memcpy(data, bh->b_data+offset, tocopy);
5953 		brelse(bh);
5954 		offset = 0;
5955 		toread -= tocopy;
5956 		data += tocopy;
5957 		blk++;
5958 	}
5959 	return len;
5960 }
5961 
5962 /* Write to quotafile (we know the transaction is already started and has
5963  * enough credits) */
5964 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5965 				const char *data, size_t len, loff_t off)
5966 {
5967 	struct inode *inode = sb_dqopt(sb)->files[type];
5968 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5969 	int err, offset = off & (sb->s_blocksize - 1);
5970 	int retries = 0;
5971 	struct buffer_head *bh;
5972 	handle_t *handle = journal_current_handle();
5973 
5974 	if (EXT4_SB(sb)->s_journal && !handle) {
5975 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5976 			" cancelled because transaction is not started",
5977 			(unsigned long long)off, (unsigned long long)len);
5978 		return -EIO;
5979 	}
5980 	/*
5981 	 * Since we account only one data block in transaction credits,
5982 	 * then it is impossible to cross a block boundary.
5983 	 */
5984 	if (sb->s_blocksize - offset < len) {
5985 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5986 			" cancelled because not block aligned",
5987 			(unsigned long long)off, (unsigned long long)len);
5988 		return -EIO;
5989 	}
5990 
5991 	do {
5992 		bh = ext4_bread(handle, inode, blk,
5993 				EXT4_GET_BLOCKS_CREATE |
5994 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5995 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5996 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5997 	if (IS_ERR(bh))
5998 		return PTR_ERR(bh);
5999 	if (!bh)
6000 		goto out;
6001 	BUFFER_TRACE(bh, "get write access");
6002 	err = ext4_journal_get_write_access(handle, bh);
6003 	if (err) {
6004 		brelse(bh);
6005 		return err;
6006 	}
6007 	lock_buffer(bh);
6008 	memcpy(bh->b_data+offset, data, len);
6009 	flush_dcache_page(bh->b_page);
6010 	unlock_buffer(bh);
6011 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6012 	brelse(bh);
6013 out:
6014 	if (inode->i_size < off + len) {
6015 		i_size_write(inode, off + len);
6016 		EXT4_I(inode)->i_disksize = inode->i_size;
6017 		ext4_mark_inode_dirty(handle, inode);
6018 	}
6019 	return len;
6020 }
6021 #endif
6022 
6023 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6024 		       const char *dev_name, void *data)
6025 {
6026 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6027 }
6028 
6029 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6030 static inline void register_as_ext2(void)
6031 {
6032 	int err = register_filesystem(&ext2_fs_type);
6033 	if (err)
6034 		printk(KERN_WARNING
6035 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6036 }
6037 
6038 static inline void unregister_as_ext2(void)
6039 {
6040 	unregister_filesystem(&ext2_fs_type);
6041 }
6042 
6043 static inline int ext2_feature_set_ok(struct super_block *sb)
6044 {
6045 	if (ext4_has_unknown_ext2_incompat_features(sb))
6046 		return 0;
6047 	if (sb_rdonly(sb))
6048 		return 1;
6049 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6050 		return 0;
6051 	return 1;
6052 }
6053 #else
6054 static inline void register_as_ext2(void) { }
6055 static inline void unregister_as_ext2(void) { }
6056 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6057 #endif
6058 
6059 static inline void register_as_ext3(void)
6060 {
6061 	int err = register_filesystem(&ext3_fs_type);
6062 	if (err)
6063 		printk(KERN_WARNING
6064 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6065 }
6066 
6067 static inline void unregister_as_ext3(void)
6068 {
6069 	unregister_filesystem(&ext3_fs_type);
6070 }
6071 
6072 static inline int ext3_feature_set_ok(struct super_block *sb)
6073 {
6074 	if (ext4_has_unknown_ext3_incompat_features(sb))
6075 		return 0;
6076 	if (!ext4_has_feature_journal(sb))
6077 		return 0;
6078 	if (sb_rdonly(sb))
6079 		return 1;
6080 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6081 		return 0;
6082 	return 1;
6083 }
6084 
6085 static struct file_system_type ext4_fs_type = {
6086 	.owner		= THIS_MODULE,
6087 	.name		= "ext4",
6088 	.mount		= ext4_mount,
6089 	.kill_sb	= kill_block_super,
6090 	.fs_flags	= FS_REQUIRES_DEV,
6091 };
6092 MODULE_ALIAS_FS("ext4");
6093 
6094 /* Shared across all ext4 file systems */
6095 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6096 
6097 static int __init ext4_init_fs(void)
6098 {
6099 	int i, err;
6100 
6101 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6102 	ext4_li_info = NULL;
6103 	mutex_init(&ext4_li_mtx);
6104 
6105 	/* Build-time check for flags consistency */
6106 	ext4_check_flag_values();
6107 
6108 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6109 		init_waitqueue_head(&ext4__ioend_wq[i]);
6110 
6111 	err = ext4_init_es();
6112 	if (err)
6113 		return err;
6114 
6115 	err = ext4_init_pending();
6116 	if (err)
6117 		goto out7;
6118 
6119 	err = ext4_init_post_read_processing();
6120 	if (err)
6121 		goto out6;
6122 
6123 	err = ext4_init_pageio();
6124 	if (err)
6125 		goto out5;
6126 
6127 	err = ext4_init_system_zone();
6128 	if (err)
6129 		goto out4;
6130 
6131 	err = ext4_init_sysfs();
6132 	if (err)
6133 		goto out3;
6134 
6135 	err = ext4_init_mballoc();
6136 	if (err)
6137 		goto out2;
6138 	err = init_inodecache();
6139 	if (err)
6140 		goto out1;
6141 	register_as_ext3();
6142 	register_as_ext2();
6143 	err = register_filesystem(&ext4_fs_type);
6144 	if (err)
6145 		goto out;
6146 
6147 	return 0;
6148 out:
6149 	unregister_as_ext2();
6150 	unregister_as_ext3();
6151 	destroy_inodecache();
6152 out1:
6153 	ext4_exit_mballoc();
6154 out2:
6155 	ext4_exit_sysfs();
6156 out3:
6157 	ext4_exit_system_zone();
6158 out4:
6159 	ext4_exit_pageio();
6160 out5:
6161 	ext4_exit_post_read_processing();
6162 out6:
6163 	ext4_exit_pending();
6164 out7:
6165 	ext4_exit_es();
6166 
6167 	return err;
6168 }
6169 
6170 static void __exit ext4_exit_fs(void)
6171 {
6172 	ext4_destroy_lazyinit_thread();
6173 	unregister_as_ext2();
6174 	unregister_as_ext3();
6175 	unregister_filesystem(&ext4_fs_type);
6176 	destroy_inodecache();
6177 	ext4_exit_mballoc();
6178 	ext4_exit_sysfs();
6179 	ext4_exit_system_zone();
6180 	ext4_exit_pageio();
6181 	ext4_exit_post_read_processing();
6182 	ext4_exit_es();
6183 	ext4_exit_pending();
6184 }
6185 
6186 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6187 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6188 MODULE_LICENSE("GPL");
6189 MODULE_SOFTDEP("pre: crc32c");
6190 module_init(ext4_init_fs)
6191 module_exit(ext4_exit_fs)
6192