xref: /openbmc/linux/fs/ext4/super.c (revision 08283d30)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext4/super.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/fs/minix/inode.c
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  *
16  *  Big-endian to little-endian byte-swapping/bitmaps by
17  *        David S. Miller (davem@caip.rutgers.edu), 1995
18  */
19 
20 #include <linux/module.h>
21 #include <linux/string.h>
22 #include <linux/fs.h>
23 #include <linux/time.h>
24 #include <linux/vmalloc.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/backing-dev.h>
29 #include <linux/parser.h>
30 #include <linux/buffer_head.h>
31 #include <linux/exportfs.h>
32 #include <linux/vfs.h>
33 #include <linux/random.h>
34 #include <linux/mount.h>
35 #include <linux/namei.h>
36 #include <linux/quotaops.h>
37 #include <linux/seq_file.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/dax.h>
42 #include <linux/cleancache.h>
43 #include <linux/uaccess.h>
44 #include <linux/iversion.h>
45 #include <linux/unicode.h>
46 
47 #include <linux/kthread.h>
48 #include <linux/freezer.h>
49 
50 #include "ext4.h"
51 #include "ext4_extents.h"	/* Needed for trace points definition */
52 #include "ext4_jbd2.h"
53 #include "xattr.h"
54 #include "acl.h"
55 #include "mballoc.h"
56 #include "fsmap.h"
57 
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/ext4.h>
60 
61 static struct ext4_lazy_init *ext4_li_info;
62 static struct mutex ext4_li_mtx;
63 static struct ratelimit_state ext4_mount_msg_ratelimit;
64 
65 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
66 			     unsigned long journal_devnum);
67 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
68 static int ext4_commit_super(struct super_block *sb, int sync);
69 static void ext4_mark_recovery_complete(struct super_block *sb,
70 					struct ext4_super_block *es);
71 static void ext4_clear_journal_err(struct super_block *sb,
72 				   struct ext4_super_block *es);
73 static int ext4_sync_fs(struct super_block *sb, int wait);
74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
76 static int ext4_unfreeze(struct super_block *sb);
77 static int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79 		       const char *dev_name, void *data);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86 static struct inode *ext4_get_journal_inode(struct super_block *sb,
87 					    unsigned int journal_inum);
88 
89 /*
90  * Lock ordering
91  *
92  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
93  * i_mmap_rwsem (inode->i_mmap_rwsem)!
94  *
95  * page fault path:
96  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
97  *   page lock -> i_data_sem (rw)
98  *
99  * buffered write path:
100  * sb_start_write -> i_mutex -> mmap_sem
101  * sb_start_write -> i_mutex -> transaction start -> page lock ->
102  *   i_data_sem (rw)
103  *
104  * truncate:
105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
106  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
107  *   i_data_sem (rw)
108  *
109  * direct IO:
110  * sb_start_write -> i_mutex -> mmap_sem
111  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
112  *
113  * writepages:
114  * transaction start -> page lock(s) -> i_data_sem (rw)
115  */
116 
117 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
118 static struct file_system_type ext2_fs_type = {
119 	.owner		= THIS_MODULE,
120 	.name		= "ext2",
121 	.mount		= ext4_mount,
122 	.kill_sb	= kill_block_super,
123 	.fs_flags	= FS_REQUIRES_DEV,
124 };
125 MODULE_ALIAS_FS("ext2");
126 MODULE_ALIAS("ext2");
127 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
128 #else
129 #define IS_EXT2_SB(sb) (0)
130 #endif
131 
132 
133 static struct file_system_type ext3_fs_type = {
134 	.owner		= THIS_MODULE,
135 	.name		= "ext3",
136 	.mount		= ext4_mount,
137 	.kill_sb	= kill_block_super,
138 	.fs_flags	= FS_REQUIRES_DEV,
139 };
140 MODULE_ALIAS_FS("ext3");
141 MODULE_ALIAS("ext3");
142 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
143 
144 /*
145  * This works like sb_bread() except it uses ERR_PTR for error
146  * returns.  Currently with sb_bread it's impossible to distinguish
147  * between ENOMEM and EIO situations (since both result in a NULL
148  * return.
149  */
150 struct buffer_head *
151 ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
152 {
153 	struct buffer_head *bh = sb_getblk(sb, block);
154 
155 	if (bh == NULL)
156 		return ERR_PTR(-ENOMEM);
157 	if (buffer_uptodate(bh))
158 		return bh;
159 	ll_rw_block(REQ_OP_READ, REQ_META | op_flags, 1, &bh);
160 	wait_on_buffer(bh);
161 	if (buffer_uptodate(bh))
162 		return bh;
163 	put_bh(bh);
164 	return ERR_PTR(-EIO);
165 }
166 
167 static int ext4_verify_csum_type(struct super_block *sb,
168 				 struct ext4_super_block *es)
169 {
170 	if (!ext4_has_feature_metadata_csum(sb))
171 		return 1;
172 
173 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
174 }
175 
176 static __le32 ext4_superblock_csum(struct super_block *sb,
177 				   struct ext4_super_block *es)
178 {
179 	struct ext4_sb_info *sbi = EXT4_SB(sb);
180 	int offset = offsetof(struct ext4_super_block, s_checksum);
181 	__u32 csum;
182 
183 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
184 
185 	return cpu_to_le32(csum);
186 }
187 
188 static int ext4_superblock_csum_verify(struct super_block *sb,
189 				       struct ext4_super_block *es)
190 {
191 	if (!ext4_has_metadata_csum(sb))
192 		return 1;
193 
194 	return es->s_checksum == ext4_superblock_csum(sb, es);
195 }
196 
197 void ext4_superblock_csum_set(struct super_block *sb)
198 {
199 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
200 
201 	if (!ext4_has_metadata_csum(sb))
202 		return;
203 
204 	es->s_checksum = ext4_superblock_csum(sb, es);
205 }
206 
207 void *ext4_kvmalloc(size_t size, gfp_t flags)
208 {
209 	void *ret;
210 
211 	ret = kmalloc(size, flags | __GFP_NOWARN);
212 	if (!ret)
213 		ret = __vmalloc(size, flags, PAGE_KERNEL);
214 	return ret;
215 }
216 
217 void *ext4_kvzalloc(size_t size, gfp_t flags)
218 {
219 	void *ret;
220 
221 	ret = kzalloc(size, flags | __GFP_NOWARN);
222 	if (!ret)
223 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
224 	return ret;
225 }
226 
227 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
228 			       struct ext4_group_desc *bg)
229 {
230 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
231 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
233 }
234 
235 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
236 			       struct ext4_group_desc *bg)
237 {
238 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
239 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
240 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
241 }
242 
243 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
244 			      struct ext4_group_desc *bg)
245 {
246 	return le32_to_cpu(bg->bg_inode_table_lo) |
247 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
248 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
249 }
250 
251 __u32 ext4_free_group_clusters(struct super_block *sb,
252 			       struct ext4_group_desc *bg)
253 {
254 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
255 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
256 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
257 }
258 
259 __u32 ext4_free_inodes_count(struct super_block *sb,
260 			      struct ext4_group_desc *bg)
261 {
262 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
263 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
264 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
265 }
266 
267 __u32 ext4_used_dirs_count(struct super_block *sb,
268 			      struct ext4_group_desc *bg)
269 {
270 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
271 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
272 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
273 }
274 
275 __u32 ext4_itable_unused_count(struct super_block *sb,
276 			      struct ext4_group_desc *bg)
277 {
278 	return le16_to_cpu(bg->bg_itable_unused_lo) |
279 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
280 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
281 }
282 
283 void ext4_block_bitmap_set(struct super_block *sb,
284 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
285 {
286 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
287 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
289 }
290 
291 void ext4_inode_bitmap_set(struct super_block *sb,
292 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
293 {
294 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
295 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
296 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
297 }
298 
299 void ext4_inode_table_set(struct super_block *sb,
300 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
301 {
302 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
303 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
304 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
305 }
306 
307 void ext4_free_group_clusters_set(struct super_block *sb,
308 				  struct ext4_group_desc *bg, __u32 count)
309 {
310 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
311 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
312 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
313 }
314 
315 void ext4_free_inodes_set(struct super_block *sb,
316 			  struct ext4_group_desc *bg, __u32 count)
317 {
318 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
319 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
320 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
321 }
322 
323 void ext4_used_dirs_set(struct super_block *sb,
324 			  struct ext4_group_desc *bg, __u32 count)
325 {
326 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
327 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
328 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
329 }
330 
331 void ext4_itable_unused_set(struct super_block *sb,
332 			  struct ext4_group_desc *bg, __u32 count)
333 {
334 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
335 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
336 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
337 }
338 
339 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
340 {
341 	time64_t now = ktime_get_real_seconds();
342 
343 	now = clamp_val(now, 0, (1ull << 40) - 1);
344 
345 	*lo = cpu_to_le32(lower_32_bits(now));
346 	*hi = upper_32_bits(now);
347 }
348 
349 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
350 {
351 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
352 }
353 #define ext4_update_tstamp(es, tstamp) \
354 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
355 #define ext4_get_tstamp(es, tstamp) \
356 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
357 
358 static void __save_error_info(struct super_block *sb, const char *func,
359 			    unsigned int line)
360 {
361 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
362 
363 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
364 	if (bdev_read_only(sb->s_bdev))
365 		return;
366 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
367 	ext4_update_tstamp(es, s_last_error_time);
368 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
369 	es->s_last_error_line = cpu_to_le32(line);
370 	if (!es->s_first_error_time) {
371 		es->s_first_error_time = es->s_last_error_time;
372 		es->s_first_error_time_hi = es->s_last_error_time_hi;
373 		strncpy(es->s_first_error_func, func,
374 			sizeof(es->s_first_error_func));
375 		es->s_first_error_line = cpu_to_le32(line);
376 		es->s_first_error_ino = es->s_last_error_ino;
377 		es->s_first_error_block = es->s_last_error_block;
378 	}
379 	/*
380 	 * Start the daily error reporting function if it hasn't been
381 	 * started already
382 	 */
383 	if (!es->s_error_count)
384 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
385 	le32_add_cpu(&es->s_error_count, 1);
386 }
387 
388 static void save_error_info(struct super_block *sb, const char *func,
389 			    unsigned int line)
390 {
391 	__save_error_info(sb, func, line);
392 	ext4_commit_super(sb, 1);
393 }
394 
395 /*
396  * The del_gendisk() function uninitializes the disk-specific data
397  * structures, including the bdi structure, without telling anyone
398  * else.  Once this happens, any attempt to call mark_buffer_dirty()
399  * (for example, by ext4_commit_super), will cause a kernel OOPS.
400  * This is a kludge to prevent these oops until we can put in a proper
401  * hook in del_gendisk() to inform the VFS and file system layers.
402  */
403 static int block_device_ejected(struct super_block *sb)
404 {
405 	struct inode *bd_inode = sb->s_bdev->bd_inode;
406 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
407 
408 	return bdi->dev == NULL;
409 }
410 
411 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
412 {
413 	struct super_block		*sb = journal->j_private;
414 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
415 	int				error = is_journal_aborted(journal);
416 	struct ext4_journal_cb_entry	*jce;
417 
418 	BUG_ON(txn->t_state == T_FINISHED);
419 
420 	ext4_process_freed_data(sb, txn->t_tid);
421 
422 	spin_lock(&sbi->s_md_lock);
423 	while (!list_empty(&txn->t_private_list)) {
424 		jce = list_entry(txn->t_private_list.next,
425 				 struct ext4_journal_cb_entry, jce_list);
426 		list_del_init(&jce->jce_list);
427 		spin_unlock(&sbi->s_md_lock);
428 		jce->jce_func(sb, jce, error);
429 		spin_lock(&sbi->s_md_lock);
430 	}
431 	spin_unlock(&sbi->s_md_lock);
432 }
433 
434 static bool system_going_down(void)
435 {
436 	return system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF
437 		|| system_state == SYSTEM_RESTART;
438 }
439 
440 /* Deal with the reporting of failure conditions on a filesystem such as
441  * inconsistencies detected or read IO failures.
442  *
443  * On ext2, we can store the error state of the filesystem in the
444  * superblock.  That is not possible on ext4, because we may have other
445  * write ordering constraints on the superblock which prevent us from
446  * writing it out straight away; and given that the journal is about to
447  * be aborted, we can't rely on the current, or future, transactions to
448  * write out the superblock safely.
449  *
450  * We'll just use the jbd2_journal_abort() error code to record an error in
451  * the journal instead.  On recovery, the journal will complain about
452  * that error until we've noted it down and cleared it.
453  */
454 
455 static void ext4_handle_error(struct super_block *sb)
456 {
457 	if (test_opt(sb, WARN_ON_ERROR))
458 		WARN_ON_ONCE(1);
459 
460 	if (sb_rdonly(sb))
461 		return;
462 
463 	if (!test_opt(sb, ERRORS_CONT)) {
464 		journal_t *journal = EXT4_SB(sb)->s_journal;
465 
466 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
467 		if (journal)
468 			jbd2_journal_abort(journal, -EIO);
469 	}
470 	/*
471 	 * We force ERRORS_RO behavior when system is rebooting. Otherwise we
472 	 * could panic during 'reboot -f' as the underlying device got already
473 	 * disabled.
474 	 */
475 	if (test_opt(sb, ERRORS_RO) || system_going_down()) {
476 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
477 		/*
478 		 * Make sure updated value of ->s_mount_flags will be visible
479 		 * before ->s_flags update
480 		 */
481 		smp_wmb();
482 		sb->s_flags |= SB_RDONLY;
483 	} else if (test_opt(sb, ERRORS_PANIC)) {
484 		if (EXT4_SB(sb)->s_journal &&
485 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
486 			return;
487 		panic("EXT4-fs (device %s): panic forced after error\n",
488 			sb->s_id);
489 	}
490 }
491 
492 #define ext4_error_ratelimit(sb)					\
493 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
494 			     "EXT4-fs error")
495 
496 void __ext4_error(struct super_block *sb, const char *function,
497 		  unsigned int line, const char *fmt, ...)
498 {
499 	struct va_format vaf;
500 	va_list args;
501 
502 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
503 		return;
504 
505 	trace_ext4_error(sb, function, line);
506 	if (ext4_error_ratelimit(sb)) {
507 		va_start(args, fmt);
508 		vaf.fmt = fmt;
509 		vaf.va = &args;
510 		printk(KERN_CRIT
511 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
512 		       sb->s_id, function, line, current->comm, &vaf);
513 		va_end(args);
514 	}
515 	save_error_info(sb, function, line);
516 	ext4_handle_error(sb);
517 }
518 
519 void __ext4_error_inode(struct inode *inode, const char *function,
520 			unsigned int line, ext4_fsblk_t block,
521 			const char *fmt, ...)
522 {
523 	va_list args;
524 	struct va_format vaf;
525 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
526 
527 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
528 		return;
529 
530 	trace_ext4_error(inode->i_sb, function, line);
531 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
532 	es->s_last_error_block = cpu_to_le64(block);
533 	if (ext4_error_ratelimit(inode->i_sb)) {
534 		va_start(args, fmt);
535 		vaf.fmt = fmt;
536 		vaf.va = &args;
537 		if (block)
538 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
539 			       "inode #%lu: block %llu: comm %s: %pV\n",
540 			       inode->i_sb->s_id, function, line, inode->i_ino,
541 			       block, current->comm, &vaf);
542 		else
543 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
544 			       "inode #%lu: comm %s: %pV\n",
545 			       inode->i_sb->s_id, function, line, inode->i_ino,
546 			       current->comm, &vaf);
547 		va_end(args);
548 	}
549 	save_error_info(inode->i_sb, function, line);
550 	ext4_handle_error(inode->i_sb);
551 }
552 
553 void __ext4_error_file(struct file *file, const char *function,
554 		       unsigned int line, ext4_fsblk_t block,
555 		       const char *fmt, ...)
556 {
557 	va_list args;
558 	struct va_format vaf;
559 	struct ext4_super_block *es;
560 	struct inode *inode = file_inode(file);
561 	char pathname[80], *path;
562 
563 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
564 		return;
565 
566 	trace_ext4_error(inode->i_sb, function, line);
567 	es = EXT4_SB(inode->i_sb)->s_es;
568 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
569 	if (ext4_error_ratelimit(inode->i_sb)) {
570 		path = file_path(file, pathname, sizeof(pathname));
571 		if (IS_ERR(path))
572 			path = "(unknown)";
573 		va_start(args, fmt);
574 		vaf.fmt = fmt;
575 		vaf.va = &args;
576 		if (block)
577 			printk(KERN_CRIT
578 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
579 			       "block %llu: comm %s: path %s: %pV\n",
580 			       inode->i_sb->s_id, function, line, inode->i_ino,
581 			       block, current->comm, path, &vaf);
582 		else
583 			printk(KERN_CRIT
584 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
585 			       "comm %s: path %s: %pV\n",
586 			       inode->i_sb->s_id, function, line, inode->i_ino,
587 			       current->comm, path, &vaf);
588 		va_end(args);
589 	}
590 	save_error_info(inode->i_sb, function, line);
591 	ext4_handle_error(inode->i_sb);
592 }
593 
594 const char *ext4_decode_error(struct super_block *sb, int errno,
595 			      char nbuf[16])
596 {
597 	char *errstr = NULL;
598 
599 	switch (errno) {
600 	case -EFSCORRUPTED:
601 		errstr = "Corrupt filesystem";
602 		break;
603 	case -EFSBADCRC:
604 		errstr = "Filesystem failed CRC";
605 		break;
606 	case -EIO:
607 		errstr = "IO failure";
608 		break;
609 	case -ENOMEM:
610 		errstr = "Out of memory";
611 		break;
612 	case -EROFS:
613 		if (!sb || (EXT4_SB(sb)->s_journal &&
614 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
615 			errstr = "Journal has aborted";
616 		else
617 			errstr = "Readonly filesystem";
618 		break;
619 	default:
620 		/* If the caller passed in an extra buffer for unknown
621 		 * errors, textualise them now.  Else we just return
622 		 * NULL. */
623 		if (nbuf) {
624 			/* Check for truncated error codes... */
625 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
626 				errstr = nbuf;
627 		}
628 		break;
629 	}
630 
631 	return errstr;
632 }
633 
634 /* __ext4_std_error decodes expected errors from journaling functions
635  * automatically and invokes the appropriate error response.  */
636 
637 void __ext4_std_error(struct super_block *sb, const char *function,
638 		      unsigned int line, int errno)
639 {
640 	char nbuf[16];
641 	const char *errstr;
642 
643 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
644 		return;
645 
646 	/* Special case: if the error is EROFS, and we're not already
647 	 * inside a transaction, then there's really no point in logging
648 	 * an error. */
649 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
650 		return;
651 
652 	if (ext4_error_ratelimit(sb)) {
653 		errstr = ext4_decode_error(sb, errno, nbuf);
654 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
655 		       sb->s_id, function, line, errstr);
656 	}
657 
658 	save_error_info(sb, function, line);
659 	ext4_handle_error(sb);
660 }
661 
662 /*
663  * ext4_abort is a much stronger failure handler than ext4_error.  The
664  * abort function may be used to deal with unrecoverable failures such
665  * as journal IO errors or ENOMEM at a critical moment in log management.
666  *
667  * We unconditionally force the filesystem into an ABORT|READONLY state,
668  * unless the error response on the fs has been set to panic in which
669  * case we take the easy way out and panic immediately.
670  */
671 
672 void __ext4_abort(struct super_block *sb, const char *function,
673 		unsigned int line, const char *fmt, ...)
674 {
675 	struct va_format vaf;
676 	va_list args;
677 
678 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
679 		return;
680 
681 	save_error_info(sb, function, line);
682 	va_start(args, fmt);
683 	vaf.fmt = fmt;
684 	vaf.va = &args;
685 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
686 	       sb->s_id, function, line, &vaf);
687 	va_end(args);
688 
689 	if (sb_rdonly(sb) == 0) {
690 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
691 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
692 		/*
693 		 * Make sure updated value of ->s_mount_flags will be visible
694 		 * before ->s_flags update
695 		 */
696 		smp_wmb();
697 		sb->s_flags |= SB_RDONLY;
698 		if (EXT4_SB(sb)->s_journal)
699 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
700 		save_error_info(sb, function, line);
701 	}
702 	if (test_opt(sb, ERRORS_PANIC) && !system_going_down()) {
703 		if (EXT4_SB(sb)->s_journal &&
704 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
705 			return;
706 		panic("EXT4-fs panic from previous error\n");
707 	}
708 }
709 
710 void __ext4_msg(struct super_block *sb,
711 		const char *prefix, const char *fmt, ...)
712 {
713 	struct va_format vaf;
714 	va_list args;
715 
716 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
717 		return;
718 
719 	va_start(args, fmt);
720 	vaf.fmt = fmt;
721 	vaf.va = &args;
722 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
723 	va_end(args);
724 }
725 
726 #define ext4_warning_ratelimit(sb)					\
727 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
728 			     "EXT4-fs warning")
729 
730 void __ext4_warning(struct super_block *sb, const char *function,
731 		    unsigned int line, const char *fmt, ...)
732 {
733 	struct va_format vaf;
734 	va_list args;
735 
736 	if (!ext4_warning_ratelimit(sb))
737 		return;
738 
739 	va_start(args, fmt);
740 	vaf.fmt = fmt;
741 	vaf.va = &args;
742 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
743 	       sb->s_id, function, line, &vaf);
744 	va_end(args);
745 }
746 
747 void __ext4_warning_inode(const struct inode *inode, const char *function,
748 			  unsigned int line, const char *fmt, ...)
749 {
750 	struct va_format vaf;
751 	va_list args;
752 
753 	if (!ext4_warning_ratelimit(inode->i_sb))
754 		return;
755 
756 	va_start(args, fmt);
757 	vaf.fmt = fmt;
758 	vaf.va = &args;
759 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
760 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
761 	       function, line, inode->i_ino, current->comm, &vaf);
762 	va_end(args);
763 }
764 
765 void __ext4_grp_locked_error(const char *function, unsigned int line,
766 			     struct super_block *sb, ext4_group_t grp,
767 			     unsigned long ino, ext4_fsblk_t block,
768 			     const char *fmt, ...)
769 __releases(bitlock)
770 __acquires(bitlock)
771 {
772 	struct va_format vaf;
773 	va_list args;
774 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
775 
776 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
777 		return;
778 
779 	trace_ext4_error(sb, function, line);
780 	es->s_last_error_ino = cpu_to_le32(ino);
781 	es->s_last_error_block = cpu_to_le64(block);
782 	__save_error_info(sb, function, line);
783 
784 	if (ext4_error_ratelimit(sb)) {
785 		va_start(args, fmt);
786 		vaf.fmt = fmt;
787 		vaf.va = &args;
788 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
789 		       sb->s_id, function, line, grp);
790 		if (ino)
791 			printk(KERN_CONT "inode %lu: ", ino);
792 		if (block)
793 			printk(KERN_CONT "block %llu:",
794 			       (unsigned long long) block);
795 		printk(KERN_CONT "%pV\n", &vaf);
796 		va_end(args);
797 	}
798 
799 	if (test_opt(sb, WARN_ON_ERROR))
800 		WARN_ON_ONCE(1);
801 
802 	if (test_opt(sb, ERRORS_CONT)) {
803 		ext4_commit_super(sb, 0);
804 		return;
805 	}
806 
807 	ext4_unlock_group(sb, grp);
808 	ext4_commit_super(sb, 1);
809 	ext4_handle_error(sb);
810 	/*
811 	 * We only get here in the ERRORS_RO case; relocking the group
812 	 * may be dangerous, but nothing bad will happen since the
813 	 * filesystem will have already been marked read/only and the
814 	 * journal has been aborted.  We return 1 as a hint to callers
815 	 * who might what to use the return value from
816 	 * ext4_grp_locked_error() to distinguish between the
817 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
818 	 * aggressively from the ext4 function in question, with a
819 	 * more appropriate error code.
820 	 */
821 	ext4_lock_group(sb, grp);
822 	return;
823 }
824 
825 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
826 				     ext4_group_t group,
827 				     unsigned int flags)
828 {
829 	struct ext4_sb_info *sbi = EXT4_SB(sb);
830 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
831 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
832 	int ret;
833 
834 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
835 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
836 					    &grp->bb_state);
837 		if (!ret)
838 			percpu_counter_sub(&sbi->s_freeclusters_counter,
839 					   grp->bb_free);
840 	}
841 
842 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
843 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
844 					    &grp->bb_state);
845 		if (!ret && gdp) {
846 			int count;
847 
848 			count = ext4_free_inodes_count(sb, gdp);
849 			percpu_counter_sub(&sbi->s_freeinodes_counter,
850 					   count);
851 		}
852 	}
853 }
854 
855 void ext4_update_dynamic_rev(struct super_block *sb)
856 {
857 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
858 
859 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
860 		return;
861 
862 	ext4_warning(sb,
863 		     "updating to rev %d because of new feature flag, "
864 		     "running e2fsck is recommended",
865 		     EXT4_DYNAMIC_REV);
866 
867 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
868 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
869 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
870 	/* leave es->s_feature_*compat flags alone */
871 	/* es->s_uuid will be set by e2fsck if empty */
872 
873 	/*
874 	 * The rest of the superblock fields should be zero, and if not it
875 	 * means they are likely already in use, so leave them alone.  We
876 	 * can leave it up to e2fsck to clean up any inconsistencies there.
877 	 */
878 }
879 
880 /*
881  * Open the external journal device
882  */
883 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
884 {
885 	struct block_device *bdev;
886 	char b[BDEVNAME_SIZE];
887 
888 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
889 	if (IS_ERR(bdev))
890 		goto fail;
891 	return bdev;
892 
893 fail:
894 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
895 			__bdevname(dev, b), PTR_ERR(bdev));
896 	return NULL;
897 }
898 
899 /*
900  * Release the journal device
901  */
902 static void ext4_blkdev_put(struct block_device *bdev)
903 {
904 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
905 }
906 
907 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
908 {
909 	struct block_device *bdev;
910 	bdev = sbi->journal_bdev;
911 	if (bdev) {
912 		ext4_blkdev_put(bdev);
913 		sbi->journal_bdev = NULL;
914 	}
915 }
916 
917 static inline struct inode *orphan_list_entry(struct list_head *l)
918 {
919 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
920 }
921 
922 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
923 {
924 	struct list_head *l;
925 
926 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
927 		 le32_to_cpu(sbi->s_es->s_last_orphan));
928 
929 	printk(KERN_ERR "sb_info orphan list:\n");
930 	list_for_each(l, &sbi->s_orphan) {
931 		struct inode *inode = orphan_list_entry(l);
932 		printk(KERN_ERR "  "
933 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
934 		       inode->i_sb->s_id, inode->i_ino, inode,
935 		       inode->i_mode, inode->i_nlink,
936 		       NEXT_ORPHAN(inode));
937 	}
938 }
939 
940 #ifdef CONFIG_QUOTA
941 static int ext4_quota_off(struct super_block *sb, int type);
942 
943 static inline void ext4_quota_off_umount(struct super_block *sb)
944 {
945 	int type;
946 
947 	/* Use our quota_off function to clear inode flags etc. */
948 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
949 		ext4_quota_off(sb, type);
950 }
951 
952 /*
953  * This is a helper function which is used in the mount/remount
954  * codepaths (which holds s_umount) to fetch the quota file name.
955  */
956 static inline char *get_qf_name(struct super_block *sb,
957 				struct ext4_sb_info *sbi,
958 				int type)
959 {
960 	return rcu_dereference_protected(sbi->s_qf_names[type],
961 					 lockdep_is_held(&sb->s_umount));
962 }
963 #else
964 static inline void ext4_quota_off_umount(struct super_block *sb)
965 {
966 }
967 #endif
968 
969 static void ext4_put_super(struct super_block *sb)
970 {
971 	struct ext4_sb_info *sbi = EXT4_SB(sb);
972 	struct ext4_super_block *es = sbi->s_es;
973 	int aborted = 0;
974 	int i, err;
975 
976 	ext4_unregister_li_request(sb);
977 	ext4_quota_off_umount(sb);
978 
979 	destroy_workqueue(sbi->rsv_conversion_wq);
980 
981 	if (sbi->s_journal) {
982 		aborted = is_journal_aborted(sbi->s_journal);
983 		err = jbd2_journal_destroy(sbi->s_journal);
984 		sbi->s_journal = NULL;
985 		if ((err < 0) && !aborted)
986 			ext4_abort(sb, "Couldn't clean up the journal");
987 	}
988 
989 	ext4_unregister_sysfs(sb);
990 	ext4_es_unregister_shrinker(sbi);
991 	del_timer_sync(&sbi->s_err_report);
992 	ext4_release_system_zone(sb);
993 	ext4_mb_release(sb);
994 	ext4_ext_release(sb);
995 
996 	if (!sb_rdonly(sb) && !aborted) {
997 		ext4_clear_feature_journal_needs_recovery(sb);
998 		es->s_state = cpu_to_le16(sbi->s_mount_state);
999 	}
1000 	if (!sb_rdonly(sb))
1001 		ext4_commit_super(sb, 1);
1002 
1003 	for (i = 0; i < sbi->s_gdb_count; i++)
1004 		brelse(sbi->s_group_desc[i]);
1005 	kvfree(sbi->s_group_desc);
1006 	kvfree(sbi->s_flex_groups);
1007 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
1008 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
1009 	percpu_counter_destroy(&sbi->s_dirs_counter);
1010 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1011 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
1012 #ifdef CONFIG_QUOTA
1013 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1014 		kfree(get_qf_name(sb, sbi, i));
1015 #endif
1016 
1017 	/* Debugging code just in case the in-memory inode orphan list
1018 	 * isn't empty.  The on-disk one can be non-empty if we've
1019 	 * detected an error and taken the fs readonly, but the
1020 	 * in-memory list had better be clean by this point. */
1021 	if (!list_empty(&sbi->s_orphan))
1022 		dump_orphan_list(sb, sbi);
1023 	J_ASSERT(list_empty(&sbi->s_orphan));
1024 
1025 	sync_blockdev(sb->s_bdev);
1026 	invalidate_bdev(sb->s_bdev);
1027 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1028 		/*
1029 		 * Invalidate the journal device's buffers.  We don't want them
1030 		 * floating about in memory - the physical journal device may
1031 		 * hotswapped, and it breaks the `ro-after' testing code.
1032 		 */
1033 		sync_blockdev(sbi->journal_bdev);
1034 		invalidate_bdev(sbi->journal_bdev);
1035 		ext4_blkdev_remove(sbi);
1036 	}
1037 
1038 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1039 	sbi->s_ea_inode_cache = NULL;
1040 
1041 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1042 	sbi->s_ea_block_cache = NULL;
1043 
1044 	if (sbi->s_mmp_tsk)
1045 		kthread_stop(sbi->s_mmp_tsk);
1046 	brelse(sbi->s_sbh);
1047 	sb->s_fs_info = NULL;
1048 	/*
1049 	 * Now that we are completely done shutting down the
1050 	 * superblock, we need to actually destroy the kobject.
1051 	 */
1052 	kobject_put(&sbi->s_kobj);
1053 	wait_for_completion(&sbi->s_kobj_unregister);
1054 	if (sbi->s_chksum_driver)
1055 		crypto_free_shash(sbi->s_chksum_driver);
1056 	kfree(sbi->s_blockgroup_lock);
1057 	fs_put_dax(sbi->s_daxdev);
1058 #ifdef CONFIG_UNICODE
1059 	utf8_unload(sbi->s_encoding);
1060 #endif
1061 	kfree(sbi);
1062 }
1063 
1064 static struct kmem_cache *ext4_inode_cachep;
1065 
1066 /*
1067  * Called inside transaction, so use GFP_NOFS
1068  */
1069 static struct inode *ext4_alloc_inode(struct super_block *sb)
1070 {
1071 	struct ext4_inode_info *ei;
1072 
1073 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1074 	if (!ei)
1075 		return NULL;
1076 
1077 	inode_set_iversion(&ei->vfs_inode, 1);
1078 	spin_lock_init(&ei->i_raw_lock);
1079 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1080 	spin_lock_init(&ei->i_prealloc_lock);
1081 	ext4_es_init_tree(&ei->i_es_tree);
1082 	rwlock_init(&ei->i_es_lock);
1083 	INIT_LIST_HEAD(&ei->i_es_list);
1084 	ei->i_es_all_nr = 0;
1085 	ei->i_es_shk_nr = 0;
1086 	ei->i_es_shrink_lblk = 0;
1087 	ei->i_reserved_data_blocks = 0;
1088 	ei->i_da_metadata_calc_len = 0;
1089 	ei->i_da_metadata_calc_last_lblock = 0;
1090 	spin_lock_init(&(ei->i_block_reservation_lock));
1091 	ext4_init_pending_tree(&ei->i_pending_tree);
1092 #ifdef CONFIG_QUOTA
1093 	ei->i_reserved_quota = 0;
1094 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1095 #endif
1096 	ei->jinode = NULL;
1097 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1098 	spin_lock_init(&ei->i_completed_io_lock);
1099 	ei->i_sync_tid = 0;
1100 	ei->i_datasync_tid = 0;
1101 	atomic_set(&ei->i_unwritten, 0);
1102 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1103 	return &ei->vfs_inode;
1104 }
1105 
1106 static int ext4_drop_inode(struct inode *inode)
1107 {
1108 	int drop = generic_drop_inode(inode);
1109 
1110 	if (!drop)
1111 		drop = fscrypt_drop_inode(inode);
1112 
1113 	trace_ext4_drop_inode(inode, drop);
1114 	return drop;
1115 }
1116 
1117 static void ext4_free_in_core_inode(struct inode *inode)
1118 {
1119 	fscrypt_free_inode(inode);
1120 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1121 }
1122 
1123 static void ext4_destroy_inode(struct inode *inode)
1124 {
1125 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1126 		ext4_msg(inode->i_sb, KERN_ERR,
1127 			 "Inode %lu (%p): orphan list check failed!",
1128 			 inode->i_ino, EXT4_I(inode));
1129 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1130 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1131 				true);
1132 		dump_stack();
1133 	}
1134 }
1135 
1136 static void init_once(void *foo)
1137 {
1138 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1139 
1140 	INIT_LIST_HEAD(&ei->i_orphan);
1141 	init_rwsem(&ei->xattr_sem);
1142 	init_rwsem(&ei->i_data_sem);
1143 	init_rwsem(&ei->i_mmap_sem);
1144 	inode_init_once(&ei->vfs_inode);
1145 }
1146 
1147 static int __init init_inodecache(void)
1148 {
1149 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1150 				sizeof(struct ext4_inode_info), 0,
1151 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1152 					SLAB_ACCOUNT),
1153 				offsetof(struct ext4_inode_info, i_data),
1154 				sizeof_field(struct ext4_inode_info, i_data),
1155 				init_once);
1156 	if (ext4_inode_cachep == NULL)
1157 		return -ENOMEM;
1158 	return 0;
1159 }
1160 
1161 static void destroy_inodecache(void)
1162 {
1163 	/*
1164 	 * Make sure all delayed rcu free inodes are flushed before we
1165 	 * destroy cache.
1166 	 */
1167 	rcu_barrier();
1168 	kmem_cache_destroy(ext4_inode_cachep);
1169 }
1170 
1171 void ext4_clear_inode(struct inode *inode)
1172 {
1173 	invalidate_inode_buffers(inode);
1174 	clear_inode(inode);
1175 	dquot_drop(inode);
1176 	ext4_discard_preallocations(inode);
1177 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1178 	if (EXT4_I(inode)->jinode) {
1179 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1180 					       EXT4_I(inode)->jinode);
1181 		jbd2_free_inode(EXT4_I(inode)->jinode);
1182 		EXT4_I(inode)->jinode = NULL;
1183 	}
1184 	fscrypt_put_encryption_info(inode);
1185 	fsverity_cleanup_inode(inode);
1186 }
1187 
1188 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1189 					u64 ino, u32 generation)
1190 {
1191 	struct inode *inode;
1192 
1193 	/*
1194 	 * Currently we don't know the generation for parent directory, so
1195 	 * a generation of 0 means "accept any"
1196 	 */
1197 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1198 	if (IS_ERR(inode))
1199 		return ERR_CAST(inode);
1200 	if (generation && inode->i_generation != generation) {
1201 		iput(inode);
1202 		return ERR_PTR(-ESTALE);
1203 	}
1204 
1205 	return inode;
1206 }
1207 
1208 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1209 					int fh_len, int fh_type)
1210 {
1211 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1212 				    ext4_nfs_get_inode);
1213 }
1214 
1215 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1216 					int fh_len, int fh_type)
1217 {
1218 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1219 				    ext4_nfs_get_inode);
1220 }
1221 
1222 static int ext4_nfs_commit_metadata(struct inode *inode)
1223 {
1224 	struct writeback_control wbc = {
1225 		.sync_mode = WB_SYNC_ALL
1226 	};
1227 
1228 	trace_ext4_nfs_commit_metadata(inode);
1229 	return ext4_write_inode(inode, &wbc);
1230 }
1231 
1232 /*
1233  * Try to release metadata pages (indirect blocks, directories) which are
1234  * mapped via the block device.  Since these pages could have journal heads
1235  * which would prevent try_to_free_buffers() from freeing them, we must use
1236  * jbd2 layer's try_to_free_buffers() function to release them.
1237  */
1238 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1239 				 gfp_t wait)
1240 {
1241 	journal_t *journal = EXT4_SB(sb)->s_journal;
1242 
1243 	WARN_ON(PageChecked(page));
1244 	if (!page_has_buffers(page))
1245 		return 0;
1246 	if (journal)
1247 		return jbd2_journal_try_to_free_buffers(journal, page,
1248 						wait & ~__GFP_DIRECT_RECLAIM);
1249 	return try_to_free_buffers(page);
1250 }
1251 
1252 #ifdef CONFIG_FS_ENCRYPTION
1253 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1254 {
1255 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1256 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1257 }
1258 
1259 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1260 							void *fs_data)
1261 {
1262 	handle_t *handle = fs_data;
1263 	int res, res2, credits, retries = 0;
1264 
1265 	/*
1266 	 * Encrypting the root directory is not allowed because e2fsck expects
1267 	 * lost+found to exist and be unencrypted, and encrypting the root
1268 	 * directory would imply encrypting the lost+found directory as well as
1269 	 * the filename "lost+found" itself.
1270 	 */
1271 	if (inode->i_ino == EXT4_ROOT_INO)
1272 		return -EPERM;
1273 
1274 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1275 		return -EINVAL;
1276 
1277 	res = ext4_convert_inline_data(inode);
1278 	if (res)
1279 		return res;
1280 
1281 	/*
1282 	 * If a journal handle was specified, then the encryption context is
1283 	 * being set on a new inode via inheritance and is part of a larger
1284 	 * transaction to create the inode.  Otherwise the encryption context is
1285 	 * being set on an existing inode in its own transaction.  Only in the
1286 	 * latter case should the "retry on ENOSPC" logic be used.
1287 	 */
1288 
1289 	if (handle) {
1290 		res = ext4_xattr_set_handle(handle, inode,
1291 					    EXT4_XATTR_INDEX_ENCRYPTION,
1292 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1293 					    ctx, len, 0);
1294 		if (!res) {
1295 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1296 			ext4_clear_inode_state(inode,
1297 					EXT4_STATE_MAY_INLINE_DATA);
1298 			/*
1299 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1300 			 * S_DAX may be disabled
1301 			 */
1302 			ext4_set_inode_flags(inode);
1303 		}
1304 		return res;
1305 	}
1306 
1307 	res = dquot_initialize(inode);
1308 	if (res)
1309 		return res;
1310 retry:
1311 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1312 				     &credits);
1313 	if (res)
1314 		return res;
1315 
1316 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1317 	if (IS_ERR(handle))
1318 		return PTR_ERR(handle);
1319 
1320 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1321 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1322 				    ctx, len, 0);
1323 	if (!res) {
1324 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1325 		/*
1326 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1327 		 * S_DAX may be disabled
1328 		 */
1329 		ext4_set_inode_flags(inode);
1330 		res = ext4_mark_inode_dirty(handle, inode);
1331 		if (res)
1332 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1333 	}
1334 	res2 = ext4_journal_stop(handle);
1335 
1336 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1337 		goto retry;
1338 	if (!res)
1339 		res = res2;
1340 	return res;
1341 }
1342 
1343 static bool ext4_dummy_context(struct inode *inode)
1344 {
1345 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1346 }
1347 
1348 static const struct fscrypt_operations ext4_cryptops = {
1349 	.key_prefix		= "ext4:",
1350 	.get_context		= ext4_get_context,
1351 	.set_context		= ext4_set_context,
1352 	.dummy_context		= ext4_dummy_context,
1353 	.empty_dir		= ext4_empty_dir,
1354 	.max_namelen		= EXT4_NAME_LEN,
1355 };
1356 #endif
1357 
1358 #ifdef CONFIG_QUOTA
1359 static const char * const quotatypes[] = INITQFNAMES;
1360 #define QTYPE2NAME(t) (quotatypes[t])
1361 
1362 static int ext4_write_dquot(struct dquot *dquot);
1363 static int ext4_acquire_dquot(struct dquot *dquot);
1364 static int ext4_release_dquot(struct dquot *dquot);
1365 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1366 static int ext4_write_info(struct super_block *sb, int type);
1367 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1368 			 const struct path *path);
1369 static int ext4_quota_on_mount(struct super_block *sb, int type);
1370 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1371 			       size_t len, loff_t off);
1372 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1373 				const char *data, size_t len, loff_t off);
1374 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1375 			     unsigned int flags);
1376 static int ext4_enable_quotas(struct super_block *sb);
1377 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1378 
1379 static struct dquot **ext4_get_dquots(struct inode *inode)
1380 {
1381 	return EXT4_I(inode)->i_dquot;
1382 }
1383 
1384 static const struct dquot_operations ext4_quota_operations = {
1385 	.get_reserved_space	= ext4_get_reserved_space,
1386 	.write_dquot		= ext4_write_dquot,
1387 	.acquire_dquot		= ext4_acquire_dquot,
1388 	.release_dquot		= ext4_release_dquot,
1389 	.mark_dirty		= ext4_mark_dquot_dirty,
1390 	.write_info		= ext4_write_info,
1391 	.alloc_dquot		= dquot_alloc,
1392 	.destroy_dquot		= dquot_destroy,
1393 	.get_projid		= ext4_get_projid,
1394 	.get_inode_usage	= ext4_get_inode_usage,
1395 	.get_next_id		= ext4_get_next_id,
1396 };
1397 
1398 static const struct quotactl_ops ext4_qctl_operations = {
1399 	.quota_on	= ext4_quota_on,
1400 	.quota_off	= ext4_quota_off,
1401 	.quota_sync	= dquot_quota_sync,
1402 	.get_state	= dquot_get_state,
1403 	.set_info	= dquot_set_dqinfo,
1404 	.get_dqblk	= dquot_get_dqblk,
1405 	.set_dqblk	= dquot_set_dqblk,
1406 	.get_nextdqblk	= dquot_get_next_dqblk,
1407 };
1408 #endif
1409 
1410 static const struct super_operations ext4_sops = {
1411 	.alloc_inode	= ext4_alloc_inode,
1412 	.free_inode	= ext4_free_in_core_inode,
1413 	.destroy_inode	= ext4_destroy_inode,
1414 	.write_inode	= ext4_write_inode,
1415 	.dirty_inode	= ext4_dirty_inode,
1416 	.drop_inode	= ext4_drop_inode,
1417 	.evict_inode	= ext4_evict_inode,
1418 	.put_super	= ext4_put_super,
1419 	.sync_fs	= ext4_sync_fs,
1420 	.freeze_fs	= ext4_freeze,
1421 	.unfreeze_fs	= ext4_unfreeze,
1422 	.statfs		= ext4_statfs,
1423 	.remount_fs	= ext4_remount,
1424 	.show_options	= ext4_show_options,
1425 #ifdef CONFIG_QUOTA
1426 	.quota_read	= ext4_quota_read,
1427 	.quota_write	= ext4_quota_write,
1428 	.get_dquots	= ext4_get_dquots,
1429 #endif
1430 	.bdev_try_to_free_page = bdev_try_to_free_page,
1431 };
1432 
1433 static const struct export_operations ext4_export_ops = {
1434 	.fh_to_dentry = ext4_fh_to_dentry,
1435 	.fh_to_parent = ext4_fh_to_parent,
1436 	.get_parent = ext4_get_parent,
1437 	.commit_metadata = ext4_nfs_commit_metadata,
1438 };
1439 
1440 enum {
1441 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1442 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1443 	Opt_nouid32, Opt_debug, Opt_removed,
1444 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1445 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1446 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1447 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1448 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1449 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1450 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1451 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1452 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1453 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1454 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1455 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1456 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1457 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1458 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1459 	Opt_dioread_nolock, Opt_dioread_lock,
1460 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1461 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1462 };
1463 
1464 static const match_table_t tokens = {
1465 	{Opt_bsd_df, "bsddf"},
1466 	{Opt_minix_df, "minixdf"},
1467 	{Opt_grpid, "grpid"},
1468 	{Opt_grpid, "bsdgroups"},
1469 	{Opt_nogrpid, "nogrpid"},
1470 	{Opt_nogrpid, "sysvgroups"},
1471 	{Opt_resgid, "resgid=%u"},
1472 	{Opt_resuid, "resuid=%u"},
1473 	{Opt_sb, "sb=%u"},
1474 	{Opt_err_cont, "errors=continue"},
1475 	{Opt_err_panic, "errors=panic"},
1476 	{Opt_err_ro, "errors=remount-ro"},
1477 	{Opt_nouid32, "nouid32"},
1478 	{Opt_debug, "debug"},
1479 	{Opt_removed, "oldalloc"},
1480 	{Opt_removed, "orlov"},
1481 	{Opt_user_xattr, "user_xattr"},
1482 	{Opt_nouser_xattr, "nouser_xattr"},
1483 	{Opt_acl, "acl"},
1484 	{Opt_noacl, "noacl"},
1485 	{Opt_noload, "norecovery"},
1486 	{Opt_noload, "noload"},
1487 	{Opt_removed, "nobh"},
1488 	{Opt_removed, "bh"},
1489 	{Opt_commit, "commit=%u"},
1490 	{Opt_min_batch_time, "min_batch_time=%u"},
1491 	{Opt_max_batch_time, "max_batch_time=%u"},
1492 	{Opt_journal_dev, "journal_dev=%u"},
1493 	{Opt_journal_path, "journal_path=%s"},
1494 	{Opt_journal_checksum, "journal_checksum"},
1495 	{Opt_nojournal_checksum, "nojournal_checksum"},
1496 	{Opt_journal_async_commit, "journal_async_commit"},
1497 	{Opt_abort, "abort"},
1498 	{Opt_data_journal, "data=journal"},
1499 	{Opt_data_ordered, "data=ordered"},
1500 	{Opt_data_writeback, "data=writeback"},
1501 	{Opt_data_err_abort, "data_err=abort"},
1502 	{Opt_data_err_ignore, "data_err=ignore"},
1503 	{Opt_offusrjquota, "usrjquota="},
1504 	{Opt_usrjquota, "usrjquota=%s"},
1505 	{Opt_offgrpjquota, "grpjquota="},
1506 	{Opt_grpjquota, "grpjquota=%s"},
1507 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1508 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1509 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1510 	{Opt_grpquota, "grpquota"},
1511 	{Opt_noquota, "noquota"},
1512 	{Opt_quota, "quota"},
1513 	{Opt_usrquota, "usrquota"},
1514 	{Opt_prjquota, "prjquota"},
1515 	{Opt_barrier, "barrier=%u"},
1516 	{Opt_barrier, "barrier"},
1517 	{Opt_nobarrier, "nobarrier"},
1518 	{Opt_i_version, "i_version"},
1519 	{Opt_dax, "dax"},
1520 	{Opt_stripe, "stripe=%u"},
1521 	{Opt_delalloc, "delalloc"},
1522 	{Opt_warn_on_error, "warn_on_error"},
1523 	{Opt_nowarn_on_error, "nowarn_on_error"},
1524 	{Opt_lazytime, "lazytime"},
1525 	{Opt_nolazytime, "nolazytime"},
1526 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1527 	{Opt_nodelalloc, "nodelalloc"},
1528 	{Opt_removed, "mblk_io_submit"},
1529 	{Opt_removed, "nomblk_io_submit"},
1530 	{Opt_block_validity, "block_validity"},
1531 	{Opt_noblock_validity, "noblock_validity"},
1532 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1533 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1534 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1535 	{Opt_auto_da_alloc, "auto_da_alloc"},
1536 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1537 	{Opt_dioread_nolock, "dioread_nolock"},
1538 	{Opt_dioread_lock, "dioread_lock"},
1539 	{Opt_discard, "discard"},
1540 	{Opt_nodiscard, "nodiscard"},
1541 	{Opt_init_itable, "init_itable=%u"},
1542 	{Opt_init_itable, "init_itable"},
1543 	{Opt_noinit_itable, "noinit_itable"},
1544 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1545 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1546 	{Opt_nombcache, "nombcache"},
1547 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1548 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1549 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1550 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1551 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1552 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1553 	{Opt_err, NULL},
1554 };
1555 
1556 static ext4_fsblk_t get_sb_block(void **data)
1557 {
1558 	ext4_fsblk_t	sb_block;
1559 	char		*options = (char *) *data;
1560 
1561 	if (!options || strncmp(options, "sb=", 3) != 0)
1562 		return 1;	/* Default location */
1563 
1564 	options += 3;
1565 	/* TODO: use simple_strtoll with >32bit ext4 */
1566 	sb_block = simple_strtoul(options, &options, 0);
1567 	if (*options && *options != ',') {
1568 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1569 		       (char *) *data);
1570 		return 1;
1571 	}
1572 	if (*options == ',')
1573 		options++;
1574 	*data = (void *) options;
1575 
1576 	return sb_block;
1577 }
1578 
1579 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1580 static const char deprecated_msg[] =
1581 	"Mount option \"%s\" will be removed by %s\n"
1582 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1583 
1584 #ifdef CONFIG_QUOTA
1585 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1586 {
1587 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1588 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1589 	int ret = -1;
1590 
1591 	if (sb_any_quota_loaded(sb) && !old_qname) {
1592 		ext4_msg(sb, KERN_ERR,
1593 			"Cannot change journaled "
1594 			"quota options when quota turned on");
1595 		return -1;
1596 	}
1597 	if (ext4_has_feature_quota(sb)) {
1598 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1599 			 "ignored when QUOTA feature is enabled");
1600 		return 1;
1601 	}
1602 	qname = match_strdup(args);
1603 	if (!qname) {
1604 		ext4_msg(sb, KERN_ERR,
1605 			"Not enough memory for storing quotafile name");
1606 		return -1;
1607 	}
1608 	if (old_qname) {
1609 		if (strcmp(old_qname, qname) == 0)
1610 			ret = 1;
1611 		else
1612 			ext4_msg(sb, KERN_ERR,
1613 				 "%s quota file already specified",
1614 				 QTYPE2NAME(qtype));
1615 		goto errout;
1616 	}
1617 	if (strchr(qname, '/')) {
1618 		ext4_msg(sb, KERN_ERR,
1619 			"quotafile must be on filesystem root");
1620 		goto errout;
1621 	}
1622 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1623 	set_opt(sb, QUOTA);
1624 	return 1;
1625 errout:
1626 	kfree(qname);
1627 	return ret;
1628 }
1629 
1630 static int clear_qf_name(struct super_block *sb, int qtype)
1631 {
1632 
1633 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1634 	char *old_qname = get_qf_name(sb, sbi, qtype);
1635 
1636 	if (sb_any_quota_loaded(sb) && old_qname) {
1637 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1638 			" when quota turned on");
1639 		return -1;
1640 	}
1641 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1642 	synchronize_rcu();
1643 	kfree(old_qname);
1644 	return 1;
1645 }
1646 #endif
1647 
1648 #define MOPT_SET	0x0001
1649 #define MOPT_CLEAR	0x0002
1650 #define MOPT_NOSUPPORT	0x0004
1651 #define MOPT_EXPLICIT	0x0008
1652 #define MOPT_CLEAR_ERR	0x0010
1653 #define MOPT_GTE0	0x0020
1654 #ifdef CONFIG_QUOTA
1655 #define MOPT_Q		0
1656 #define MOPT_QFMT	0x0040
1657 #else
1658 #define MOPT_Q		MOPT_NOSUPPORT
1659 #define MOPT_QFMT	MOPT_NOSUPPORT
1660 #endif
1661 #define MOPT_DATAJ	0x0080
1662 #define MOPT_NO_EXT2	0x0100
1663 #define MOPT_NO_EXT3	0x0200
1664 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1665 #define MOPT_STRING	0x0400
1666 
1667 static const struct mount_opts {
1668 	int	token;
1669 	int	mount_opt;
1670 	int	flags;
1671 } ext4_mount_opts[] = {
1672 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1673 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1674 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1675 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1676 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1677 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1678 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1679 	 MOPT_EXT4_ONLY | MOPT_SET},
1680 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1681 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1682 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1683 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1684 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1685 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1686 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1687 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1688 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1689 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1690 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1691 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1692 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1693 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1694 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1695 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1696 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1697 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1698 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1699 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1700 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1701 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1702 	 MOPT_NO_EXT2},
1703 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1704 	 MOPT_NO_EXT2},
1705 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1706 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1707 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1708 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1709 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1710 	{Opt_commit, 0, MOPT_GTE0},
1711 	{Opt_max_batch_time, 0, MOPT_GTE0},
1712 	{Opt_min_batch_time, 0, MOPT_GTE0},
1713 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1714 	{Opt_init_itable, 0, MOPT_GTE0},
1715 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1716 	{Opt_stripe, 0, MOPT_GTE0},
1717 	{Opt_resuid, 0, MOPT_GTE0},
1718 	{Opt_resgid, 0, MOPT_GTE0},
1719 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1720 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1721 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1722 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1723 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1724 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1725 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1726 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1727 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1728 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1729 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1730 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1731 #else
1732 	{Opt_acl, 0, MOPT_NOSUPPORT},
1733 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1734 #endif
1735 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1736 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1737 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1738 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1739 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1740 							MOPT_SET | MOPT_Q},
1741 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1742 							MOPT_SET | MOPT_Q},
1743 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1744 							MOPT_SET | MOPT_Q},
1745 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1746 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1747 							MOPT_CLEAR | MOPT_Q},
1748 	{Opt_usrjquota, 0, MOPT_Q},
1749 	{Opt_grpjquota, 0, MOPT_Q},
1750 	{Opt_offusrjquota, 0, MOPT_Q},
1751 	{Opt_offgrpjquota, 0, MOPT_Q},
1752 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1753 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1754 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1755 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1756 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1757 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1758 	{Opt_err, 0, 0}
1759 };
1760 
1761 #ifdef CONFIG_UNICODE
1762 static const struct ext4_sb_encodings {
1763 	__u16 magic;
1764 	char *name;
1765 	char *version;
1766 } ext4_sb_encoding_map[] = {
1767 	{EXT4_ENC_UTF8_12_1, "utf8", "12.1.0"},
1768 };
1769 
1770 static int ext4_sb_read_encoding(const struct ext4_super_block *es,
1771 				 const struct ext4_sb_encodings **encoding,
1772 				 __u16 *flags)
1773 {
1774 	__u16 magic = le16_to_cpu(es->s_encoding);
1775 	int i;
1776 
1777 	for (i = 0; i < ARRAY_SIZE(ext4_sb_encoding_map); i++)
1778 		if (magic == ext4_sb_encoding_map[i].magic)
1779 			break;
1780 
1781 	if (i >= ARRAY_SIZE(ext4_sb_encoding_map))
1782 		return -EINVAL;
1783 
1784 	*encoding = &ext4_sb_encoding_map[i];
1785 	*flags = le16_to_cpu(es->s_encoding_flags);
1786 
1787 	return 0;
1788 }
1789 #endif
1790 
1791 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1792 			    substring_t *args, unsigned long *journal_devnum,
1793 			    unsigned int *journal_ioprio, int is_remount)
1794 {
1795 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1796 	const struct mount_opts *m;
1797 	kuid_t uid;
1798 	kgid_t gid;
1799 	int arg = 0;
1800 
1801 #ifdef CONFIG_QUOTA
1802 	if (token == Opt_usrjquota)
1803 		return set_qf_name(sb, USRQUOTA, &args[0]);
1804 	else if (token == Opt_grpjquota)
1805 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1806 	else if (token == Opt_offusrjquota)
1807 		return clear_qf_name(sb, USRQUOTA);
1808 	else if (token == Opt_offgrpjquota)
1809 		return clear_qf_name(sb, GRPQUOTA);
1810 #endif
1811 	switch (token) {
1812 	case Opt_noacl:
1813 	case Opt_nouser_xattr:
1814 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1815 		break;
1816 	case Opt_sb:
1817 		return 1;	/* handled by get_sb_block() */
1818 	case Opt_removed:
1819 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1820 		return 1;
1821 	case Opt_abort:
1822 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1823 		return 1;
1824 	case Opt_i_version:
1825 		sb->s_flags |= SB_I_VERSION;
1826 		return 1;
1827 	case Opt_lazytime:
1828 		sb->s_flags |= SB_LAZYTIME;
1829 		return 1;
1830 	case Opt_nolazytime:
1831 		sb->s_flags &= ~SB_LAZYTIME;
1832 		return 1;
1833 	}
1834 
1835 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1836 		if (token == m->token)
1837 			break;
1838 
1839 	if (m->token == Opt_err) {
1840 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1841 			 "or missing value", opt);
1842 		return -1;
1843 	}
1844 
1845 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1846 		ext4_msg(sb, KERN_ERR,
1847 			 "Mount option \"%s\" incompatible with ext2", opt);
1848 		return -1;
1849 	}
1850 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1851 		ext4_msg(sb, KERN_ERR,
1852 			 "Mount option \"%s\" incompatible with ext3", opt);
1853 		return -1;
1854 	}
1855 
1856 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1857 		return -1;
1858 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1859 		return -1;
1860 	if (m->flags & MOPT_EXPLICIT) {
1861 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1862 			set_opt2(sb, EXPLICIT_DELALLOC);
1863 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1864 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1865 		} else
1866 			return -1;
1867 	}
1868 	if (m->flags & MOPT_CLEAR_ERR)
1869 		clear_opt(sb, ERRORS_MASK);
1870 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1871 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1872 			 "options when quota turned on");
1873 		return -1;
1874 	}
1875 
1876 	if (m->flags & MOPT_NOSUPPORT) {
1877 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1878 	} else if (token == Opt_commit) {
1879 		if (arg == 0)
1880 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1881 		else if (arg > INT_MAX / HZ) {
1882 			ext4_msg(sb, KERN_ERR,
1883 				 "Invalid commit interval %d, "
1884 				 "must be smaller than %d",
1885 				 arg, INT_MAX / HZ);
1886 			return -1;
1887 		}
1888 		sbi->s_commit_interval = HZ * arg;
1889 	} else if (token == Opt_debug_want_extra_isize) {
1890 		sbi->s_want_extra_isize = arg;
1891 	} else if (token == Opt_max_batch_time) {
1892 		sbi->s_max_batch_time = arg;
1893 	} else if (token == Opt_min_batch_time) {
1894 		sbi->s_min_batch_time = arg;
1895 	} else if (token == Opt_inode_readahead_blks) {
1896 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1897 			ext4_msg(sb, KERN_ERR,
1898 				 "EXT4-fs: inode_readahead_blks must be "
1899 				 "0 or a power of 2 smaller than 2^31");
1900 			return -1;
1901 		}
1902 		sbi->s_inode_readahead_blks = arg;
1903 	} else if (token == Opt_init_itable) {
1904 		set_opt(sb, INIT_INODE_TABLE);
1905 		if (!args->from)
1906 			arg = EXT4_DEF_LI_WAIT_MULT;
1907 		sbi->s_li_wait_mult = arg;
1908 	} else if (token == Opt_max_dir_size_kb) {
1909 		sbi->s_max_dir_size_kb = arg;
1910 	} else if (token == Opt_stripe) {
1911 		sbi->s_stripe = arg;
1912 	} else if (token == Opt_resuid) {
1913 		uid = make_kuid(current_user_ns(), arg);
1914 		if (!uid_valid(uid)) {
1915 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1916 			return -1;
1917 		}
1918 		sbi->s_resuid = uid;
1919 	} else if (token == Opt_resgid) {
1920 		gid = make_kgid(current_user_ns(), arg);
1921 		if (!gid_valid(gid)) {
1922 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1923 			return -1;
1924 		}
1925 		sbi->s_resgid = gid;
1926 	} else if (token == Opt_journal_dev) {
1927 		if (is_remount) {
1928 			ext4_msg(sb, KERN_ERR,
1929 				 "Cannot specify journal on remount");
1930 			return -1;
1931 		}
1932 		*journal_devnum = arg;
1933 	} else if (token == Opt_journal_path) {
1934 		char *journal_path;
1935 		struct inode *journal_inode;
1936 		struct path path;
1937 		int error;
1938 
1939 		if (is_remount) {
1940 			ext4_msg(sb, KERN_ERR,
1941 				 "Cannot specify journal on remount");
1942 			return -1;
1943 		}
1944 		journal_path = match_strdup(&args[0]);
1945 		if (!journal_path) {
1946 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1947 				"journal device string");
1948 			return -1;
1949 		}
1950 
1951 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1952 		if (error) {
1953 			ext4_msg(sb, KERN_ERR, "error: could not find "
1954 				"journal device path: error %d", error);
1955 			kfree(journal_path);
1956 			return -1;
1957 		}
1958 
1959 		journal_inode = d_inode(path.dentry);
1960 		if (!S_ISBLK(journal_inode->i_mode)) {
1961 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1962 				"is not a block device", journal_path);
1963 			path_put(&path);
1964 			kfree(journal_path);
1965 			return -1;
1966 		}
1967 
1968 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1969 		path_put(&path);
1970 		kfree(journal_path);
1971 	} else if (token == Opt_journal_ioprio) {
1972 		if (arg > 7) {
1973 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1974 				 " (must be 0-7)");
1975 			return -1;
1976 		}
1977 		*journal_ioprio =
1978 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1979 	} else if (token == Opt_test_dummy_encryption) {
1980 #ifdef CONFIG_FS_ENCRYPTION
1981 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1982 		ext4_msg(sb, KERN_WARNING,
1983 			 "Test dummy encryption mode enabled");
1984 #else
1985 		ext4_msg(sb, KERN_WARNING,
1986 			 "Test dummy encryption mount option ignored");
1987 #endif
1988 	} else if (m->flags & MOPT_DATAJ) {
1989 		if (is_remount) {
1990 			if (!sbi->s_journal)
1991 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1992 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1993 				ext4_msg(sb, KERN_ERR,
1994 					 "Cannot change data mode on remount");
1995 				return -1;
1996 			}
1997 		} else {
1998 			clear_opt(sb, DATA_FLAGS);
1999 			sbi->s_mount_opt |= m->mount_opt;
2000 		}
2001 #ifdef CONFIG_QUOTA
2002 	} else if (m->flags & MOPT_QFMT) {
2003 		if (sb_any_quota_loaded(sb) &&
2004 		    sbi->s_jquota_fmt != m->mount_opt) {
2005 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
2006 				 "quota options when quota turned on");
2007 			return -1;
2008 		}
2009 		if (ext4_has_feature_quota(sb)) {
2010 			ext4_msg(sb, KERN_INFO,
2011 				 "Quota format mount options ignored "
2012 				 "when QUOTA feature is enabled");
2013 			return 1;
2014 		}
2015 		sbi->s_jquota_fmt = m->mount_opt;
2016 #endif
2017 	} else if (token == Opt_dax) {
2018 #ifdef CONFIG_FS_DAX
2019 		ext4_msg(sb, KERN_WARNING,
2020 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
2021 		sbi->s_mount_opt |= m->mount_opt;
2022 #else
2023 		ext4_msg(sb, KERN_INFO, "dax option not supported");
2024 		return -1;
2025 #endif
2026 	} else if (token == Opt_data_err_abort) {
2027 		sbi->s_mount_opt |= m->mount_opt;
2028 	} else if (token == Opt_data_err_ignore) {
2029 		sbi->s_mount_opt &= ~m->mount_opt;
2030 	} else {
2031 		if (!args->from)
2032 			arg = 1;
2033 		if (m->flags & MOPT_CLEAR)
2034 			arg = !arg;
2035 		else if (unlikely(!(m->flags & MOPT_SET))) {
2036 			ext4_msg(sb, KERN_WARNING,
2037 				 "buggy handling of option %s", opt);
2038 			WARN_ON(1);
2039 			return -1;
2040 		}
2041 		if (arg != 0)
2042 			sbi->s_mount_opt |= m->mount_opt;
2043 		else
2044 			sbi->s_mount_opt &= ~m->mount_opt;
2045 	}
2046 	return 1;
2047 }
2048 
2049 static int parse_options(char *options, struct super_block *sb,
2050 			 unsigned long *journal_devnum,
2051 			 unsigned int *journal_ioprio,
2052 			 int is_remount)
2053 {
2054 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2055 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2056 	substring_t args[MAX_OPT_ARGS];
2057 	int token;
2058 
2059 	if (!options)
2060 		return 1;
2061 
2062 	while ((p = strsep(&options, ",")) != NULL) {
2063 		if (!*p)
2064 			continue;
2065 		/*
2066 		 * Initialize args struct so we know whether arg was
2067 		 * found; some options take optional arguments.
2068 		 */
2069 		args[0].to = args[0].from = NULL;
2070 		token = match_token(p, tokens, args);
2071 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2072 				     journal_ioprio, is_remount) < 0)
2073 			return 0;
2074 	}
2075 #ifdef CONFIG_QUOTA
2076 	/*
2077 	 * We do the test below only for project quotas. 'usrquota' and
2078 	 * 'grpquota' mount options are allowed even without quota feature
2079 	 * to support legacy quotas in quota files.
2080 	 */
2081 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2082 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2083 			 "Cannot enable project quota enforcement.");
2084 		return 0;
2085 	}
2086 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2087 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2088 	if (usr_qf_name || grp_qf_name) {
2089 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2090 			clear_opt(sb, USRQUOTA);
2091 
2092 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2093 			clear_opt(sb, GRPQUOTA);
2094 
2095 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2096 			ext4_msg(sb, KERN_ERR, "old and new quota "
2097 					"format mixing");
2098 			return 0;
2099 		}
2100 
2101 		if (!sbi->s_jquota_fmt) {
2102 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2103 					"not specified");
2104 			return 0;
2105 		}
2106 	}
2107 #endif
2108 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2109 		int blocksize =
2110 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2111 
2112 		if (blocksize < PAGE_SIZE) {
2113 			ext4_msg(sb, KERN_ERR, "can't mount with "
2114 				 "dioread_nolock if block size != PAGE_SIZE");
2115 			return 0;
2116 		}
2117 	}
2118 	return 1;
2119 }
2120 
2121 static inline void ext4_show_quota_options(struct seq_file *seq,
2122 					   struct super_block *sb)
2123 {
2124 #if defined(CONFIG_QUOTA)
2125 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2126 	char *usr_qf_name, *grp_qf_name;
2127 
2128 	if (sbi->s_jquota_fmt) {
2129 		char *fmtname = "";
2130 
2131 		switch (sbi->s_jquota_fmt) {
2132 		case QFMT_VFS_OLD:
2133 			fmtname = "vfsold";
2134 			break;
2135 		case QFMT_VFS_V0:
2136 			fmtname = "vfsv0";
2137 			break;
2138 		case QFMT_VFS_V1:
2139 			fmtname = "vfsv1";
2140 			break;
2141 		}
2142 		seq_printf(seq, ",jqfmt=%s", fmtname);
2143 	}
2144 
2145 	rcu_read_lock();
2146 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2147 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2148 	if (usr_qf_name)
2149 		seq_show_option(seq, "usrjquota", usr_qf_name);
2150 	if (grp_qf_name)
2151 		seq_show_option(seq, "grpjquota", grp_qf_name);
2152 	rcu_read_unlock();
2153 #endif
2154 }
2155 
2156 static const char *token2str(int token)
2157 {
2158 	const struct match_token *t;
2159 
2160 	for (t = tokens; t->token != Opt_err; t++)
2161 		if (t->token == token && !strchr(t->pattern, '='))
2162 			break;
2163 	return t->pattern;
2164 }
2165 
2166 /*
2167  * Show an option if
2168  *  - it's set to a non-default value OR
2169  *  - if the per-sb default is different from the global default
2170  */
2171 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2172 			      int nodefs)
2173 {
2174 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2175 	struct ext4_super_block *es = sbi->s_es;
2176 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2177 	const struct mount_opts *m;
2178 	char sep = nodefs ? '\n' : ',';
2179 
2180 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2181 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2182 
2183 	if (sbi->s_sb_block != 1)
2184 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2185 
2186 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2187 		int want_set = m->flags & MOPT_SET;
2188 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2189 		    (m->flags & MOPT_CLEAR_ERR))
2190 			continue;
2191 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2192 			continue; /* skip if same as the default */
2193 		if ((want_set &&
2194 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2195 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2196 			continue; /* select Opt_noFoo vs Opt_Foo */
2197 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2198 	}
2199 
2200 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2201 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2202 		SEQ_OPTS_PRINT("resuid=%u",
2203 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2204 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2205 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2206 		SEQ_OPTS_PRINT("resgid=%u",
2207 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2208 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2209 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2210 		SEQ_OPTS_PUTS("errors=remount-ro");
2211 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2212 		SEQ_OPTS_PUTS("errors=continue");
2213 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2214 		SEQ_OPTS_PUTS("errors=panic");
2215 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2216 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2217 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2218 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2219 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2220 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2221 	if (sb->s_flags & SB_I_VERSION)
2222 		SEQ_OPTS_PUTS("i_version");
2223 	if (nodefs || sbi->s_stripe)
2224 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2225 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2226 			(sbi->s_mount_opt ^ def_mount_opt)) {
2227 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2228 			SEQ_OPTS_PUTS("data=journal");
2229 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2230 			SEQ_OPTS_PUTS("data=ordered");
2231 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2232 			SEQ_OPTS_PUTS("data=writeback");
2233 	}
2234 	if (nodefs ||
2235 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2236 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2237 			       sbi->s_inode_readahead_blks);
2238 
2239 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2240 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2241 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2242 	if (nodefs || sbi->s_max_dir_size_kb)
2243 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2244 	if (test_opt(sb, DATA_ERR_ABORT))
2245 		SEQ_OPTS_PUTS("data_err=abort");
2246 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2247 		SEQ_OPTS_PUTS("test_dummy_encryption");
2248 
2249 	ext4_show_quota_options(seq, sb);
2250 	return 0;
2251 }
2252 
2253 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2254 {
2255 	return _ext4_show_options(seq, root->d_sb, 0);
2256 }
2257 
2258 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2259 {
2260 	struct super_block *sb = seq->private;
2261 	int rc;
2262 
2263 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2264 	rc = _ext4_show_options(seq, sb, 1);
2265 	seq_puts(seq, "\n");
2266 	return rc;
2267 }
2268 
2269 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2270 			    int read_only)
2271 {
2272 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2273 	int err = 0;
2274 
2275 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2276 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2277 			 "forcing read-only mode");
2278 		err = -EROFS;
2279 	}
2280 	if (read_only)
2281 		goto done;
2282 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2283 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2284 			 "running e2fsck is recommended");
2285 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2286 		ext4_msg(sb, KERN_WARNING,
2287 			 "warning: mounting fs with errors, "
2288 			 "running e2fsck is recommended");
2289 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2290 		 le16_to_cpu(es->s_mnt_count) >=
2291 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2292 		ext4_msg(sb, KERN_WARNING,
2293 			 "warning: maximal mount count reached, "
2294 			 "running e2fsck is recommended");
2295 	else if (le32_to_cpu(es->s_checkinterval) &&
2296 		 (ext4_get_tstamp(es, s_lastcheck) +
2297 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2298 		ext4_msg(sb, KERN_WARNING,
2299 			 "warning: checktime reached, "
2300 			 "running e2fsck is recommended");
2301 	if (!sbi->s_journal)
2302 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2303 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2304 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2305 	le16_add_cpu(&es->s_mnt_count, 1);
2306 	ext4_update_tstamp(es, s_mtime);
2307 	if (sbi->s_journal)
2308 		ext4_set_feature_journal_needs_recovery(sb);
2309 
2310 	err = ext4_commit_super(sb, 1);
2311 done:
2312 	if (test_opt(sb, DEBUG))
2313 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2314 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2315 			sb->s_blocksize,
2316 			sbi->s_groups_count,
2317 			EXT4_BLOCKS_PER_GROUP(sb),
2318 			EXT4_INODES_PER_GROUP(sb),
2319 			sbi->s_mount_opt, sbi->s_mount_opt2);
2320 
2321 	cleancache_init_fs(sb);
2322 	return err;
2323 }
2324 
2325 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2326 {
2327 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2328 	struct flex_groups *new_groups;
2329 	int size;
2330 
2331 	if (!sbi->s_log_groups_per_flex)
2332 		return 0;
2333 
2334 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2335 	if (size <= sbi->s_flex_groups_allocated)
2336 		return 0;
2337 
2338 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2339 	new_groups = kvzalloc(size, GFP_KERNEL);
2340 	if (!new_groups) {
2341 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2342 			 size / (int) sizeof(struct flex_groups));
2343 		return -ENOMEM;
2344 	}
2345 
2346 	if (sbi->s_flex_groups) {
2347 		memcpy(new_groups, sbi->s_flex_groups,
2348 		       (sbi->s_flex_groups_allocated *
2349 			sizeof(struct flex_groups)));
2350 		kvfree(sbi->s_flex_groups);
2351 	}
2352 	sbi->s_flex_groups = new_groups;
2353 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2354 	return 0;
2355 }
2356 
2357 static int ext4_fill_flex_info(struct super_block *sb)
2358 {
2359 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2360 	struct ext4_group_desc *gdp = NULL;
2361 	ext4_group_t flex_group;
2362 	int i, err;
2363 
2364 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2365 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2366 		sbi->s_log_groups_per_flex = 0;
2367 		return 1;
2368 	}
2369 
2370 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2371 	if (err)
2372 		goto failed;
2373 
2374 	for (i = 0; i < sbi->s_groups_count; i++) {
2375 		gdp = ext4_get_group_desc(sb, i, NULL);
2376 
2377 		flex_group = ext4_flex_group(sbi, i);
2378 		atomic_add(ext4_free_inodes_count(sb, gdp),
2379 			   &sbi->s_flex_groups[flex_group].free_inodes);
2380 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2381 			     &sbi->s_flex_groups[flex_group].free_clusters);
2382 		atomic_add(ext4_used_dirs_count(sb, gdp),
2383 			   &sbi->s_flex_groups[flex_group].used_dirs);
2384 	}
2385 
2386 	return 1;
2387 failed:
2388 	return 0;
2389 }
2390 
2391 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2392 				   struct ext4_group_desc *gdp)
2393 {
2394 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2395 	__u16 crc = 0;
2396 	__le32 le_group = cpu_to_le32(block_group);
2397 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2398 
2399 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2400 		/* Use new metadata_csum algorithm */
2401 		__u32 csum32;
2402 		__u16 dummy_csum = 0;
2403 
2404 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2405 				     sizeof(le_group));
2406 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2407 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2408 				     sizeof(dummy_csum));
2409 		offset += sizeof(dummy_csum);
2410 		if (offset < sbi->s_desc_size)
2411 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2412 					     sbi->s_desc_size - offset);
2413 
2414 		crc = csum32 & 0xFFFF;
2415 		goto out;
2416 	}
2417 
2418 	/* old crc16 code */
2419 	if (!ext4_has_feature_gdt_csum(sb))
2420 		return 0;
2421 
2422 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2423 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2424 	crc = crc16(crc, (__u8 *)gdp, offset);
2425 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2426 	/* for checksum of struct ext4_group_desc do the rest...*/
2427 	if (ext4_has_feature_64bit(sb) &&
2428 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2429 		crc = crc16(crc, (__u8 *)gdp + offset,
2430 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2431 				offset);
2432 
2433 out:
2434 	return cpu_to_le16(crc);
2435 }
2436 
2437 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2438 				struct ext4_group_desc *gdp)
2439 {
2440 	if (ext4_has_group_desc_csum(sb) &&
2441 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2442 		return 0;
2443 
2444 	return 1;
2445 }
2446 
2447 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2448 			      struct ext4_group_desc *gdp)
2449 {
2450 	if (!ext4_has_group_desc_csum(sb))
2451 		return;
2452 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2453 }
2454 
2455 /* Called at mount-time, super-block is locked */
2456 static int ext4_check_descriptors(struct super_block *sb,
2457 				  ext4_fsblk_t sb_block,
2458 				  ext4_group_t *first_not_zeroed)
2459 {
2460 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2461 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2462 	ext4_fsblk_t last_block;
2463 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2464 	ext4_fsblk_t block_bitmap;
2465 	ext4_fsblk_t inode_bitmap;
2466 	ext4_fsblk_t inode_table;
2467 	int flexbg_flag = 0;
2468 	ext4_group_t i, grp = sbi->s_groups_count;
2469 
2470 	if (ext4_has_feature_flex_bg(sb))
2471 		flexbg_flag = 1;
2472 
2473 	ext4_debug("Checking group descriptors");
2474 
2475 	for (i = 0; i < sbi->s_groups_count; i++) {
2476 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2477 
2478 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2479 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2480 		else
2481 			last_block = first_block +
2482 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2483 
2484 		if ((grp == sbi->s_groups_count) &&
2485 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2486 			grp = i;
2487 
2488 		block_bitmap = ext4_block_bitmap(sb, gdp);
2489 		if (block_bitmap == sb_block) {
2490 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2491 				 "Block bitmap for group %u overlaps "
2492 				 "superblock", i);
2493 			if (!sb_rdonly(sb))
2494 				return 0;
2495 		}
2496 		if (block_bitmap >= sb_block + 1 &&
2497 		    block_bitmap <= last_bg_block) {
2498 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2499 				 "Block bitmap for group %u overlaps "
2500 				 "block group descriptors", i);
2501 			if (!sb_rdonly(sb))
2502 				return 0;
2503 		}
2504 		if (block_bitmap < first_block || block_bitmap > last_block) {
2505 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2506 			       "Block bitmap for group %u not in group "
2507 			       "(block %llu)!", i, block_bitmap);
2508 			return 0;
2509 		}
2510 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2511 		if (inode_bitmap == sb_block) {
2512 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2513 				 "Inode bitmap for group %u overlaps "
2514 				 "superblock", i);
2515 			if (!sb_rdonly(sb))
2516 				return 0;
2517 		}
2518 		if (inode_bitmap >= sb_block + 1 &&
2519 		    inode_bitmap <= last_bg_block) {
2520 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2521 				 "Inode bitmap for group %u overlaps "
2522 				 "block group descriptors", i);
2523 			if (!sb_rdonly(sb))
2524 				return 0;
2525 		}
2526 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2527 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2528 			       "Inode bitmap for group %u not in group "
2529 			       "(block %llu)!", i, inode_bitmap);
2530 			return 0;
2531 		}
2532 		inode_table = ext4_inode_table(sb, gdp);
2533 		if (inode_table == sb_block) {
2534 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2535 				 "Inode table for group %u overlaps "
2536 				 "superblock", i);
2537 			if (!sb_rdonly(sb))
2538 				return 0;
2539 		}
2540 		if (inode_table >= sb_block + 1 &&
2541 		    inode_table <= last_bg_block) {
2542 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2543 				 "Inode table for group %u overlaps "
2544 				 "block group descriptors", i);
2545 			if (!sb_rdonly(sb))
2546 				return 0;
2547 		}
2548 		if (inode_table < first_block ||
2549 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2550 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2551 			       "Inode table for group %u not in group "
2552 			       "(block %llu)!", i, inode_table);
2553 			return 0;
2554 		}
2555 		ext4_lock_group(sb, i);
2556 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2557 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2558 				 "Checksum for group %u failed (%u!=%u)",
2559 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2560 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2561 			if (!sb_rdonly(sb)) {
2562 				ext4_unlock_group(sb, i);
2563 				return 0;
2564 			}
2565 		}
2566 		ext4_unlock_group(sb, i);
2567 		if (!flexbg_flag)
2568 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2569 	}
2570 	if (NULL != first_not_zeroed)
2571 		*first_not_zeroed = grp;
2572 	return 1;
2573 }
2574 
2575 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2576  * the superblock) which were deleted from all directories, but held open by
2577  * a process at the time of a crash.  We walk the list and try to delete these
2578  * inodes at recovery time (only with a read-write filesystem).
2579  *
2580  * In order to keep the orphan inode chain consistent during traversal (in
2581  * case of crash during recovery), we link each inode into the superblock
2582  * orphan list_head and handle it the same way as an inode deletion during
2583  * normal operation (which journals the operations for us).
2584  *
2585  * We only do an iget() and an iput() on each inode, which is very safe if we
2586  * accidentally point at an in-use or already deleted inode.  The worst that
2587  * can happen in this case is that we get a "bit already cleared" message from
2588  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2589  * e2fsck was run on this filesystem, and it must have already done the orphan
2590  * inode cleanup for us, so we can safely abort without any further action.
2591  */
2592 static void ext4_orphan_cleanup(struct super_block *sb,
2593 				struct ext4_super_block *es)
2594 {
2595 	unsigned int s_flags = sb->s_flags;
2596 	int ret, nr_orphans = 0, nr_truncates = 0;
2597 #ifdef CONFIG_QUOTA
2598 	int quota_update = 0;
2599 	int i;
2600 #endif
2601 	if (!es->s_last_orphan) {
2602 		jbd_debug(4, "no orphan inodes to clean up\n");
2603 		return;
2604 	}
2605 
2606 	if (bdev_read_only(sb->s_bdev)) {
2607 		ext4_msg(sb, KERN_ERR, "write access "
2608 			"unavailable, skipping orphan cleanup");
2609 		return;
2610 	}
2611 
2612 	/* Check if feature set would not allow a r/w mount */
2613 	if (!ext4_feature_set_ok(sb, 0)) {
2614 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2615 			 "unknown ROCOMPAT features");
2616 		return;
2617 	}
2618 
2619 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2620 		/* don't clear list on RO mount w/ errors */
2621 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2622 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2623 				  "clearing orphan list.\n");
2624 			es->s_last_orphan = 0;
2625 		}
2626 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2627 		return;
2628 	}
2629 
2630 	if (s_flags & SB_RDONLY) {
2631 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2632 		sb->s_flags &= ~SB_RDONLY;
2633 	}
2634 #ifdef CONFIG_QUOTA
2635 	/* Needed for iput() to work correctly and not trash data */
2636 	sb->s_flags |= SB_ACTIVE;
2637 
2638 	/*
2639 	 * Turn on quotas which were not enabled for read-only mounts if
2640 	 * filesystem has quota feature, so that they are updated correctly.
2641 	 */
2642 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2643 		int ret = ext4_enable_quotas(sb);
2644 
2645 		if (!ret)
2646 			quota_update = 1;
2647 		else
2648 			ext4_msg(sb, KERN_ERR,
2649 				"Cannot turn on quotas: error %d", ret);
2650 	}
2651 
2652 	/* Turn on journaled quotas used for old sytle */
2653 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2654 		if (EXT4_SB(sb)->s_qf_names[i]) {
2655 			int ret = ext4_quota_on_mount(sb, i);
2656 
2657 			if (!ret)
2658 				quota_update = 1;
2659 			else
2660 				ext4_msg(sb, KERN_ERR,
2661 					"Cannot turn on journaled "
2662 					"quota: type %d: error %d", i, ret);
2663 		}
2664 	}
2665 #endif
2666 
2667 	while (es->s_last_orphan) {
2668 		struct inode *inode;
2669 
2670 		/*
2671 		 * We may have encountered an error during cleanup; if
2672 		 * so, skip the rest.
2673 		 */
2674 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2675 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2676 			es->s_last_orphan = 0;
2677 			break;
2678 		}
2679 
2680 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2681 		if (IS_ERR(inode)) {
2682 			es->s_last_orphan = 0;
2683 			break;
2684 		}
2685 
2686 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2687 		dquot_initialize(inode);
2688 		if (inode->i_nlink) {
2689 			if (test_opt(sb, DEBUG))
2690 				ext4_msg(sb, KERN_DEBUG,
2691 					"%s: truncating inode %lu to %lld bytes",
2692 					__func__, inode->i_ino, inode->i_size);
2693 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2694 				  inode->i_ino, inode->i_size);
2695 			inode_lock(inode);
2696 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2697 			ret = ext4_truncate(inode);
2698 			if (ret)
2699 				ext4_std_error(inode->i_sb, ret);
2700 			inode_unlock(inode);
2701 			nr_truncates++;
2702 		} else {
2703 			if (test_opt(sb, DEBUG))
2704 				ext4_msg(sb, KERN_DEBUG,
2705 					"%s: deleting unreferenced inode %lu",
2706 					__func__, inode->i_ino);
2707 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2708 				  inode->i_ino);
2709 			nr_orphans++;
2710 		}
2711 		iput(inode);  /* The delete magic happens here! */
2712 	}
2713 
2714 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2715 
2716 	if (nr_orphans)
2717 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2718 		       PLURAL(nr_orphans));
2719 	if (nr_truncates)
2720 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2721 		       PLURAL(nr_truncates));
2722 #ifdef CONFIG_QUOTA
2723 	/* Turn off quotas if they were enabled for orphan cleanup */
2724 	if (quota_update) {
2725 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2726 			if (sb_dqopt(sb)->files[i])
2727 				dquot_quota_off(sb, i);
2728 		}
2729 	}
2730 #endif
2731 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2732 }
2733 
2734 /*
2735  * Maximal extent format file size.
2736  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2737  * extent format containers, within a sector_t, and within i_blocks
2738  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2739  * so that won't be a limiting factor.
2740  *
2741  * However there is other limiting factor. We do store extents in the form
2742  * of starting block and length, hence the resulting length of the extent
2743  * covering maximum file size must fit into on-disk format containers as
2744  * well. Given that length is always by 1 unit bigger than max unit (because
2745  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2746  *
2747  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2748  */
2749 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2750 {
2751 	loff_t res;
2752 	loff_t upper_limit = MAX_LFS_FILESIZE;
2753 
2754 	BUILD_BUG_ON(sizeof(blkcnt_t) < sizeof(u64));
2755 
2756 	if (!has_huge_files) {
2757 		upper_limit = (1LL << 32) - 1;
2758 
2759 		/* total blocks in file system block size */
2760 		upper_limit >>= (blkbits - 9);
2761 		upper_limit <<= blkbits;
2762 	}
2763 
2764 	/*
2765 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2766 	 * by one fs block, so ee_len can cover the extent of maximum file
2767 	 * size
2768 	 */
2769 	res = (1LL << 32) - 1;
2770 	res <<= blkbits;
2771 
2772 	/* Sanity check against vm- & vfs- imposed limits */
2773 	if (res > upper_limit)
2774 		res = upper_limit;
2775 
2776 	return res;
2777 }
2778 
2779 /*
2780  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2781  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2782  * We need to be 1 filesystem block less than the 2^48 sector limit.
2783  */
2784 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2785 {
2786 	loff_t res = EXT4_NDIR_BLOCKS;
2787 	int meta_blocks;
2788 	loff_t upper_limit;
2789 	/* This is calculated to be the largest file size for a dense, block
2790 	 * mapped file such that the file's total number of 512-byte sectors,
2791 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2792 	 *
2793 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2794 	 * number of 512-byte sectors of the file.
2795 	 */
2796 
2797 	if (!has_huge_files) {
2798 		/*
2799 		 * !has_huge_files or implies that the inode i_block field
2800 		 * represents total file blocks in 2^32 512-byte sectors ==
2801 		 * size of vfs inode i_blocks * 8
2802 		 */
2803 		upper_limit = (1LL << 32) - 1;
2804 
2805 		/* total blocks in file system block size */
2806 		upper_limit >>= (bits - 9);
2807 
2808 	} else {
2809 		/*
2810 		 * We use 48 bit ext4_inode i_blocks
2811 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2812 		 * represent total number of blocks in
2813 		 * file system block size
2814 		 */
2815 		upper_limit = (1LL << 48) - 1;
2816 
2817 	}
2818 
2819 	/* indirect blocks */
2820 	meta_blocks = 1;
2821 	/* double indirect blocks */
2822 	meta_blocks += 1 + (1LL << (bits-2));
2823 	/* tripple indirect blocks */
2824 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2825 
2826 	upper_limit -= meta_blocks;
2827 	upper_limit <<= bits;
2828 
2829 	res += 1LL << (bits-2);
2830 	res += 1LL << (2*(bits-2));
2831 	res += 1LL << (3*(bits-2));
2832 	res <<= bits;
2833 	if (res > upper_limit)
2834 		res = upper_limit;
2835 
2836 	if (res > MAX_LFS_FILESIZE)
2837 		res = MAX_LFS_FILESIZE;
2838 
2839 	return res;
2840 }
2841 
2842 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2843 				   ext4_fsblk_t logical_sb_block, int nr)
2844 {
2845 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2846 	ext4_group_t bg, first_meta_bg;
2847 	int has_super = 0;
2848 
2849 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2850 
2851 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2852 		return logical_sb_block + nr + 1;
2853 	bg = sbi->s_desc_per_block * nr;
2854 	if (ext4_bg_has_super(sb, bg))
2855 		has_super = 1;
2856 
2857 	/*
2858 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2859 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2860 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2861 	 * compensate.
2862 	 */
2863 	if (sb->s_blocksize == 1024 && nr == 0 &&
2864 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2865 		has_super++;
2866 
2867 	return (has_super + ext4_group_first_block_no(sb, bg));
2868 }
2869 
2870 /**
2871  * ext4_get_stripe_size: Get the stripe size.
2872  * @sbi: In memory super block info
2873  *
2874  * If we have specified it via mount option, then
2875  * use the mount option value. If the value specified at mount time is
2876  * greater than the blocks per group use the super block value.
2877  * If the super block value is greater than blocks per group return 0.
2878  * Allocator needs it be less than blocks per group.
2879  *
2880  */
2881 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2882 {
2883 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2884 	unsigned long stripe_width =
2885 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2886 	int ret;
2887 
2888 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2889 		ret = sbi->s_stripe;
2890 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2891 		ret = stripe_width;
2892 	else if (stride && stride <= sbi->s_blocks_per_group)
2893 		ret = stride;
2894 	else
2895 		ret = 0;
2896 
2897 	/*
2898 	 * If the stripe width is 1, this makes no sense and
2899 	 * we set it to 0 to turn off stripe handling code.
2900 	 */
2901 	if (ret <= 1)
2902 		ret = 0;
2903 
2904 	return ret;
2905 }
2906 
2907 /*
2908  * Check whether this filesystem can be mounted based on
2909  * the features present and the RDONLY/RDWR mount requested.
2910  * Returns 1 if this filesystem can be mounted as requested,
2911  * 0 if it cannot be.
2912  */
2913 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2914 {
2915 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2916 		ext4_msg(sb, KERN_ERR,
2917 			"Couldn't mount because of "
2918 			"unsupported optional features (%x)",
2919 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2920 			~EXT4_FEATURE_INCOMPAT_SUPP));
2921 		return 0;
2922 	}
2923 
2924 #ifndef CONFIG_UNICODE
2925 	if (ext4_has_feature_casefold(sb)) {
2926 		ext4_msg(sb, KERN_ERR,
2927 			 "Filesystem with casefold feature cannot be "
2928 			 "mounted without CONFIG_UNICODE");
2929 		return 0;
2930 	}
2931 #endif
2932 
2933 	if (readonly)
2934 		return 1;
2935 
2936 	if (ext4_has_feature_readonly(sb)) {
2937 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2938 		sb->s_flags |= SB_RDONLY;
2939 		return 1;
2940 	}
2941 
2942 	/* Check that feature set is OK for a read-write mount */
2943 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2944 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2945 			 "unsupported optional features (%x)",
2946 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2947 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2948 		return 0;
2949 	}
2950 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2951 		ext4_msg(sb, KERN_ERR,
2952 			 "Can't support bigalloc feature without "
2953 			 "extents feature\n");
2954 		return 0;
2955 	}
2956 
2957 #ifndef CONFIG_QUOTA
2958 	if (ext4_has_feature_quota(sb) && !readonly) {
2959 		ext4_msg(sb, KERN_ERR,
2960 			 "Filesystem with quota feature cannot be mounted RDWR "
2961 			 "without CONFIG_QUOTA");
2962 		return 0;
2963 	}
2964 	if (ext4_has_feature_project(sb) && !readonly) {
2965 		ext4_msg(sb, KERN_ERR,
2966 			 "Filesystem with project quota feature cannot be mounted RDWR "
2967 			 "without CONFIG_QUOTA");
2968 		return 0;
2969 	}
2970 #endif  /* CONFIG_QUOTA */
2971 	return 1;
2972 }
2973 
2974 /*
2975  * This function is called once a day if we have errors logged
2976  * on the file system
2977  */
2978 static void print_daily_error_info(struct timer_list *t)
2979 {
2980 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2981 	struct super_block *sb = sbi->s_sb;
2982 	struct ext4_super_block *es = sbi->s_es;
2983 
2984 	if (es->s_error_count)
2985 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2986 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2987 			 le32_to_cpu(es->s_error_count));
2988 	if (es->s_first_error_time) {
2989 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2990 		       sb->s_id,
2991 		       ext4_get_tstamp(es, s_first_error_time),
2992 		       (int) sizeof(es->s_first_error_func),
2993 		       es->s_first_error_func,
2994 		       le32_to_cpu(es->s_first_error_line));
2995 		if (es->s_first_error_ino)
2996 			printk(KERN_CONT ": inode %u",
2997 			       le32_to_cpu(es->s_first_error_ino));
2998 		if (es->s_first_error_block)
2999 			printk(KERN_CONT ": block %llu", (unsigned long long)
3000 			       le64_to_cpu(es->s_first_error_block));
3001 		printk(KERN_CONT "\n");
3002 	}
3003 	if (es->s_last_error_time) {
3004 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
3005 		       sb->s_id,
3006 		       ext4_get_tstamp(es, s_last_error_time),
3007 		       (int) sizeof(es->s_last_error_func),
3008 		       es->s_last_error_func,
3009 		       le32_to_cpu(es->s_last_error_line));
3010 		if (es->s_last_error_ino)
3011 			printk(KERN_CONT ": inode %u",
3012 			       le32_to_cpu(es->s_last_error_ino));
3013 		if (es->s_last_error_block)
3014 			printk(KERN_CONT ": block %llu", (unsigned long long)
3015 			       le64_to_cpu(es->s_last_error_block));
3016 		printk(KERN_CONT "\n");
3017 	}
3018 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
3019 }
3020 
3021 /* Find next suitable group and run ext4_init_inode_table */
3022 static int ext4_run_li_request(struct ext4_li_request *elr)
3023 {
3024 	struct ext4_group_desc *gdp = NULL;
3025 	ext4_group_t group, ngroups;
3026 	struct super_block *sb;
3027 	unsigned long timeout = 0;
3028 	int ret = 0;
3029 
3030 	sb = elr->lr_super;
3031 	ngroups = EXT4_SB(sb)->s_groups_count;
3032 
3033 	for (group = elr->lr_next_group; group < ngroups; group++) {
3034 		gdp = ext4_get_group_desc(sb, group, NULL);
3035 		if (!gdp) {
3036 			ret = 1;
3037 			break;
3038 		}
3039 
3040 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3041 			break;
3042 	}
3043 
3044 	if (group >= ngroups)
3045 		ret = 1;
3046 
3047 	if (!ret) {
3048 		timeout = jiffies;
3049 		ret = ext4_init_inode_table(sb, group,
3050 					    elr->lr_timeout ? 0 : 1);
3051 		if (elr->lr_timeout == 0) {
3052 			timeout = (jiffies - timeout) *
3053 				  elr->lr_sbi->s_li_wait_mult;
3054 			elr->lr_timeout = timeout;
3055 		}
3056 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3057 		elr->lr_next_group = group + 1;
3058 	}
3059 	return ret;
3060 }
3061 
3062 /*
3063  * Remove lr_request from the list_request and free the
3064  * request structure. Should be called with li_list_mtx held
3065  */
3066 static void ext4_remove_li_request(struct ext4_li_request *elr)
3067 {
3068 	struct ext4_sb_info *sbi;
3069 
3070 	if (!elr)
3071 		return;
3072 
3073 	sbi = elr->lr_sbi;
3074 
3075 	list_del(&elr->lr_request);
3076 	sbi->s_li_request = NULL;
3077 	kfree(elr);
3078 }
3079 
3080 static void ext4_unregister_li_request(struct super_block *sb)
3081 {
3082 	mutex_lock(&ext4_li_mtx);
3083 	if (!ext4_li_info) {
3084 		mutex_unlock(&ext4_li_mtx);
3085 		return;
3086 	}
3087 
3088 	mutex_lock(&ext4_li_info->li_list_mtx);
3089 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3090 	mutex_unlock(&ext4_li_info->li_list_mtx);
3091 	mutex_unlock(&ext4_li_mtx);
3092 }
3093 
3094 static struct task_struct *ext4_lazyinit_task;
3095 
3096 /*
3097  * This is the function where ext4lazyinit thread lives. It walks
3098  * through the request list searching for next scheduled filesystem.
3099  * When such a fs is found, run the lazy initialization request
3100  * (ext4_rn_li_request) and keep track of the time spend in this
3101  * function. Based on that time we compute next schedule time of
3102  * the request. When walking through the list is complete, compute
3103  * next waking time and put itself into sleep.
3104  */
3105 static int ext4_lazyinit_thread(void *arg)
3106 {
3107 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3108 	struct list_head *pos, *n;
3109 	struct ext4_li_request *elr;
3110 	unsigned long next_wakeup, cur;
3111 
3112 	BUG_ON(NULL == eli);
3113 
3114 cont_thread:
3115 	while (true) {
3116 		next_wakeup = MAX_JIFFY_OFFSET;
3117 
3118 		mutex_lock(&eli->li_list_mtx);
3119 		if (list_empty(&eli->li_request_list)) {
3120 			mutex_unlock(&eli->li_list_mtx);
3121 			goto exit_thread;
3122 		}
3123 		list_for_each_safe(pos, n, &eli->li_request_list) {
3124 			int err = 0;
3125 			int progress = 0;
3126 			elr = list_entry(pos, struct ext4_li_request,
3127 					 lr_request);
3128 
3129 			if (time_before(jiffies, elr->lr_next_sched)) {
3130 				if (time_before(elr->lr_next_sched, next_wakeup))
3131 					next_wakeup = elr->lr_next_sched;
3132 				continue;
3133 			}
3134 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3135 				if (sb_start_write_trylock(elr->lr_super)) {
3136 					progress = 1;
3137 					/*
3138 					 * We hold sb->s_umount, sb can not
3139 					 * be removed from the list, it is
3140 					 * now safe to drop li_list_mtx
3141 					 */
3142 					mutex_unlock(&eli->li_list_mtx);
3143 					err = ext4_run_li_request(elr);
3144 					sb_end_write(elr->lr_super);
3145 					mutex_lock(&eli->li_list_mtx);
3146 					n = pos->next;
3147 				}
3148 				up_read((&elr->lr_super->s_umount));
3149 			}
3150 			/* error, remove the lazy_init job */
3151 			if (err) {
3152 				ext4_remove_li_request(elr);
3153 				continue;
3154 			}
3155 			if (!progress) {
3156 				elr->lr_next_sched = jiffies +
3157 					(prandom_u32()
3158 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3159 			}
3160 			if (time_before(elr->lr_next_sched, next_wakeup))
3161 				next_wakeup = elr->lr_next_sched;
3162 		}
3163 		mutex_unlock(&eli->li_list_mtx);
3164 
3165 		try_to_freeze();
3166 
3167 		cur = jiffies;
3168 		if ((time_after_eq(cur, next_wakeup)) ||
3169 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3170 			cond_resched();
3171 			continue;
3172 		}
3173 
3174 		schedule_timeout_interruptible(next_wakeup - cur);
3175 
3176 		if (kthread_should_stop()) {
3177 			ext4_clear_request_list();
3178 			goto exit_thread;
3179 		}
3180 	}
3181 
3182 exit_thread:
3183 	/*
3184 	 * It looks like the request list is empty, but we need
3185 	 * to check it under the li_list_mtx lock, to prevent any
3186 	 * additions into it, and of course we should lock ext4_li_mtx
3187 	 * to atomically free the list and ext4_li_info, because at
3188 	 * this point another ext4 filesystem could be registering
3189 	 * new one.
3190 	 */
3191 	mutex_lock(&ext4_li_mtx);
3192 	mutex_lock(&eli->li_list_mtx);
3193 	if (!list_empty(&eli->li_request_list)) {
3194 		mutex_unlock(&eli->li_list_mtx);
3195 		mutex_unlock(&ext4_li_mtx);
3196 		goto cont_thread;
3197 	}
3198 	mutex_unlock(&eli->li_list_mtx);
3199 	kfree(ext4_li_info);
3200 	ext4_li_info = NULL;
3201 	mutex_unlock(&ext4_li_mtx);
3202 
3203 	return 0;
3204 }
3205 
3206 static void ext4_clear_request_list(void)
3207 {
3208 	struct list_head *pos, *n;
3209 	struct ext4_li_request *elr;
3210 
3211 	mutex_lock(&ext4_li_info->li_list_mtx);
3212 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3213 		elr = list_entry(pos, struct ext4_li_request,
3214 				 lr_request);
3215 		ext4_remove_li_request(elr);
3216 	}
3217 	mutex_unlock(&ext4_li_info->li_list_mtx);
3218 }
3219 
3220 static int ext4_run_lazyinit_thread(void)
3221 {
3222 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3223 					 ext4_li_info, "ext4lazyinit");
3224 	if (IS_ERR(ext4_lazyinit_task)) {
3225 		int err = PTR_ERR(ext4_lazyinit_task);
3226 		ext4_clear_request_list();
3227 		kfree(ext4_li_info);
3228 		ext4_li_info = NULL;
3229 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3230 				 "initialization thread\n",
3231 				 err);
3232 		return err;
3233 	}
3234 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3235 	return 0;
3236 }
3237 
3238 /*
3239  * Check whether it make sense to run itable init. thread or not.
3240  * If there is at least one uninitialized inode table, return
3241  * corresponding group number, else the loop goes through all
3242  * groups and return total number of groups.
3243  */
3244 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3245 {
3246 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3247 	struct ext4_group_desc *gdp = NULL;
3248 
3249 	if (!ext4_has_group_desc_csum(sb))
3250 		return ngroups;
3251 
3252 	for (group = 0; group < ngroups; group++) {
3253 		gdp = ext4_get_group_desc(sb, group, NULL);
3254 		if (!gdp)
3255 			continue;
3256 
3257 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3258 			break;
3259 	}
3260 
3261 	return group;
3262 }
3263 
3264 static int ext4_li_info_new(void)
3265 {
3266 	struct ext4_lazy_init *eli = NULL;
3267 
3268 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3269 	if (!eli)
3270 		return -ENOMEM;
3271 
3272 	INIT_LIST_HEAD(&eli->li_request_list);
3273 	mutex_init(&eli->li_list_mtx);
3274 
3275 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3276 
3277 	ext4_li_info = eli;
3278 
3279 	return 0;
3280 }
3281 
3282 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3283 					    ext4_group_t start)
3284 {
3285 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3286 	struct ext4_li_request *elr;
3287 
3288 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3289 	if (!elr)
3290 		return NULL;
3291 
3292 	elr->lr_super = sb;
3293 	elr->lr_sbi = sbi;
3294 	elr->lr_next_group = start;
3295 
3296 	/*
3297 	 * Randomize first schedule time of the request to
3298 	 * spread the inode table initialization requests
3299 	 * better.
3300 	 */
3301 	elr->lr_next_sched = jiffies + (prandom_u32() %
3302 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3303 	return elr;
3304 }
3305 
3306 int ext4_register_li_request(struct super_block *sb,
3307 			     ext4_group_t first_not_zeroed)
3308 {
3309 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3310 	struct ext4_li_request *elr = NULL;
3311 	ext4_group_t ngroups = sbi->s_groups_count;
3312 	int ret = 0;
3313 
3314 	mutex_lock(&ext4_li_mtx);
3315 	if (sbi->s_li_request != NULL) {
3316 		/*
3317 		 * Reset timeout so it can be computed again, because
3318 		 * s_li_wait_mult might have changed.
3319 		 */
3320 		sbi->s_li_request->lr_timeout = 0;
3321 		goto out;
3322 	}
3323 
3324 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3325 	    !test_opt(sb, INIT_INODE_TABLE))
3326 		goto out;
3327 
3328 	elr = ext4_li_request_new(sb, first_not_zeroed);
3329 	if (!elr) {
3330 		ret = -ENOMEM;
3331 		goto out;
3332 	}
3333 
3334 	if (NULL == ext4_li_info) {
3335 		ret = ext4_li_info_new();
3336 		if (ret)
3337 			goto out;
3338 	}
3339 
3340 	mutex_lock(&ext4_li_info->li_list_mtx);
3341 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3342 	mutex_unlock(&ext4_li_info->li_list_mtx);
3343 
3344 	sbi->s_li_request = elr;
3345 	/*
3346 	 * set elr to NULL here since it has been inserted to
3347 	 * the request_list and the removal and free of it is
3348 	 * handled by ext4_clear_request_list from now on.
3349 	 */
3350 	elr = NULL;
3351 
3352 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3353 		ret = ext4_run_lazyinit_thread();
3354 		if (ret)
3355 			goto out;
3356 	}
3357 out:
3358 	mutex_unlock(&ext4_li_mtx);
3359 	if (ret)
3360 		kfree(elr);
3361 	return ret;
3362 }
3363 
3364 /*
3365  * We do not need to lock anything since this is called on
3366  * module unload.
3367  */
3368 static void ext4_destroy_lazyinit_thread(void)
3369 {
3370 	/*
3371 	 * If thread exited earlier
3372 	 * there's nothing to be done.
3373 	 */
3374 	if (!ext4_li_info || !ext4_lazyinit_task)
3375 		return;
3376 
3377 	kthread_stop(ext4_lazyinit_task);
3378 }
3379 
3380 static int set_journal_csum_feature_set(struct super_block *sb)
3381 {
3382 	int ret = 1;
3383 	int compat, incompat;
3384 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3385 
3386 	if (ext4_has_metadata_csum(sb)) {
3387 		/* journal checksum v3 */
3388 		compat = 0;
3389 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3390 	} else {
3391 		/* journal checksum v1 */
3392 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3393 		incompat = 0;
3394 	}
3395 
3396 	jbd2_journal_clear_features(sbi->s_journal,
3397 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3398 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3399 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3400 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3401 		ret = jbd2_journal_set_features(sbi->s_journal,
3402 				compat, 0,
3403 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3404 				incompat);
3405 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3406 		ret = jbd2_journal_set_features(sbi->s_journal,
3407 				compat, 0,
3408 				incompat);
3409 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3410 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3411 	} else {
3412 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3413 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3414 	}
3415 
3416 	return ret;
3417 }
3418 
3419 /*
3420  * Note: calculating the overhead so we can be compatible with
3421  * historical BSD practice is quite difficult in the face of
3422  * clusters/bigalloc.  This is because multiple metadata blocks from
3423  * different block group can end up in the same allocation cluster.
3424  * Calculating the exact overhead in the face of clustered allocation
3425  * requires either O(all block bitmaps) in memory or O(number of block
3426  * groups**2) in time.  We will still calculate the superblock for
3427  * older file systems --- and if we come across with a bigalloc file
3428  * system with zero in s_overhead_clusters the estimate will be close to
3429  * correct especially for very large cluster sizes --- but for newer
3430  * file systems, it's better to calculate this figure once at mkfs
3431  * time, and store it in the superblock.  If the superblock value is
3432  * present (even for non-bigalloc file systems), we will use it.
3433  */
3434 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3435 			  char *buf)
3436 {
3437 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3438 	struct ext4_group_desc	*gdp;
3439 	ext4_fsblk_t		first_block, last_block, b;
3440 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3441 	int			s, j, count = 0;
3442 
3443 	if (!ext4_has_feature_bigalloc(sb))
3444 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3445 			sbi->s_itb_per_group + 2);
3446 
3447 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3448 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3449 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3450 	for (i = 0; i < ngroups; i++) {
3451 		gdp = ext4_get_group_desc(sb, i, NULL);
3452 		b = ext4_block_bitmap(sb, gdp);
3453 		if (b >= first_block && b <= last_block) {
3454 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3455 			count++;
3456 		}
3457 		b = ext4_inode_bitmap(sb, gdp);
3458 		if (b >= first_block && b <= last_block) {
3459 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3460 			count++;
3461 		}
3462 		b = ext4_inode_table(sb, gdp);
3463 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3464 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3465 				int c = EXT4_B2C(sbi, b - first_block);
3466 				ext4_set_bit(c, buf);
3467 				count++;
3468 			}
3469 		if (i != grp)
3470 			continue;
3471 		s = 0;
3472 		if (ext4_bg_has_super(sb, grp)) {
3473 			ext4_set_bit(s++, buf);
3474 			count++;
3475 		}
3476 		j = ext4_bg_num_gdb(sb, grp);
3477 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3478 			ext4_error(sb, "Invalid number of block group "
3479 				   "descriptor blocks: %d", j);
3480 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3481 		}
3482 		count += j;
3483 		for (; j > 0; j--)
3484 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3485 	}
3486 	if (!count)
3487 		return 0;
3488 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3489 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3490 }
3491 
3492 /*
3493  * Compute the overhead and stash it in sbi->s_overhead
3494  */
3495 int ext4_calculate_overhead(struct super_block *sb)
3496 {
3497 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3498 	struct ext4_super_block *es = sbi->s_es;
3499 	struct inode *j_inode;
3500 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3501 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3502 	ext4_fsblk_t overhead = 0;
3503 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3504 
3505 	if (!buf)
3506 		return -ENOMEM;
3507 
3508 	/*
3509 	 * Compute the overhead (FS structures).  This is constant
3510 	 * for a given filesystem unless the number of block groups
3511 	 * changes so we cache the previous value until it does.
3512 	 */
3513 
3514 	/*
3515 	 * All of the blocks before first_data_block are overhead
3516 	 */
3517 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3518 
3519 	/*
3520 	 * Add the overhead found in each block group
3521 	 */
3522 	for (i = 0; i < ngroups; i++) {
3523 		int blks;
3524 
3525 		blks = count_overhead(sb, i, buf);
3526 		overhead += blks;
3527 		if (blks)
3528 			memset(buf, 0, PAGE_SIZE);
3529 		cond_resched();
3530 	}
3531 
3532 	/*
3533 	 * Add the internal journal blocks whether the journal has been
3534 	 * loaded or not
3535 	 */
3536 	if (sbi->s_journal && !sbi->journal_bdev)
3537 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3538 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3539 		j_inode = ext4_get_journal_inode(sb, j_inum);
3540 		if (j_inode) {
3541 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3542 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3543 			iput(j_inode);
3544 		} else {
3545 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3546 		}
3547 	}
3548 	sbi->s_overhead = overhead;
3549 	smp_wmb();
3550 	free_page((unsigned long) buf);
3551 	return 0;
3552 }
3553 
3554 static void ext4_clamp_want_extra_isize(struct super_block *sb)
3555 {
3556 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3557 	struct ext4_super_block *es = sbi->s_es;
3558 
3559 	/* determine the minimum size of new large inodes, if present */
3560 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
3561 	    sbi->s_want_extra_isize == 0) {
3562 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3563 						     EXT4_GOOD_OLD_INODE_SIZE;
3564 		if (ext4_has_feature_extra_isize(sb)) {
3565 			if (sbi->s_want_extra_isize <
3566 			    le16_to_cpu(es->s_want_extra_isize))
3567 				sbi->s_want_extra_isize =
3568 					le16_to_cpu(es->s_want_extra_isize);
3569 			if (sbi->s_want_extra_isize <
3570 			    le16_to_cpu(es->s_min_extra_isize))
3571 				sbi->s_want_extra_isize =
3572 					le16_to_cpu(es->s_min_extra_isize);
3573 		}
3574 	}
3575 	/* Check if enough inode space is available */
3576 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3577 							sbi->s_inode_size) {
3578 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3579 						       EXT4_GOOD_OLD_INODE_SIZE;
3580 		ext4_msg(sb, KERN_INFO,
3581 			 "required extra inode space not available");
3582 	}
3583 }
3584 
3585 static void ext4_set_resv_clusters(struct super_block *sb)
3586 {
3587 	ext4_fsblk_t resv_clusters;
3588 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3589 
3590 	/*
3591 	 * There's no need to reserve anything when we aren't using extents.
3592 	 * The space estimates are exact, there are no unwritten extents,
3593 	 * hole punching doesn't need new metadata... This is needed especially
3594 	 * to keep ext2/3 backward compatibility.
3595 	 */
3596 	if (!ext4_has_feature_extents(sb))
3597 		return;
3598 	/*
3599 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3600 	 * This should cover the situations where we can not afford to run
3601 	 * out of space like for example punch hole, or converting
3602 	 * unwritten extents in delalloc path. In most cases such
3603 	 * allocation would require 1, or 2 blocks, higher numbers are
3604 	 * very rare.
3605 	 */
3606 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3607 			 sbi->s_cluster_bits);
3608 
3609 	do_div(resv_clusters, 50);
3610 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3611 
3612 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3613 }
3614 
3615 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3616 {
3617 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3618 	char *orig_data = kstrdup(data, GFP_KERNEL);
3619 	struct buffer_head *bh;
3620 	struct ext4_super_block *es = NULL;
3621 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3622 	ext4_fsblk_t block;
3623 	ext4_fsblk_t sb_block = get_sb_block(&data);
3624 	ext4_fsblk_t logical_sb_block;
3625 	unsigned long offset = 0;
3626 	unsigned long journal_devnum = 0;
3627 	unsigned long def_mount_opts;
3628 	struct inode *root;
3629 	const char *descr;
3630 	int ret = -ENOMEM;
3631 	int blocksize, clustersize;
3632 	unsigned int db_count;
3633 	unsigned int i;
3634 	int needs_recovery, has_huge_files, has_bigalloc;
3635 	__u64 blocks_count;
3636 	int err = 0;
3637 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3638 	ext4_group_t first_not_zeroed;
3639 
3640 	if ((data && !orig_data) || !sbi)
3641 		goto out_free_base;
3642 
3643 	sbi->s_daxdev = dax_dev;
3644 	sbi->s_blockgroup_lock =
3645 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3646 	if (!sbi->s_blockgroup_lock)
3647 		goto out_free_base;
3648 
3649 	sb->s_fs_info = sbi;
3650 	sbi->s_sb = sb;
3651 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3652 	sbi->s_sb_block = sb_block;
3653 	if (sb->s_bdev->bd_part)
3654 		sbi->s_sectors_written_start =
3655 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3656 
3657 	/* Cleanup superblock name */
3658 	strreplace(sb->s_id, '/', '!');
3659 
3660 	/* -EINVAL is default */
3661 	ret = -EINVAL;
3662 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3663 	if (!blocksize) {
3664 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3665 		goto out_fail;
3666 	}
3667 
3668 	/*
3669 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3670 	 * block sizes.  We need to calculate the offset from buffer start.
3671 	 */
3672 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3673 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3674 		offset = do_div(logical_sb_block, blocksize);
3675 	} else {
3676 		logical_sb_block = sb_block;
3677 	}
3678 
3679 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3680 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3681 		goto out_fail;
3682 	}
3683 	/*
3684 	 * Note: s_es must be initialized as soon as possible because
3685 	 *       some ext4 macro-instructions depend on its value
3686 	 */
3687 	es = (struct ext4_super_block *) (bh->b_data + offset);
3688 	sbi->s_es = es;
3689 	sb->s_magic = le16_to_cpu(es->s_magic);
3690 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3691 		goto cantfind_ext4;
3692 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3693 
3694 	/* Warn if metadata_csum and gdt_csum are both set. */
3695 	if (ext4_has_feature_metadata_csum(sb) &&
3696 	    ext4_has_feature_gdt_csum(sb))
3697 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3698 			     "redundant flags; please run fsck.");
3699 
3700 	/* Check for a known checksum algorithm */
3701 	if (!ext4_verify_csum_type(sb, es)) {
3702 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3703 			 "unknown checksum algorithm.");
3704 		silent = 1;
3705 		goto cantfind_ext4;
3706 	}
3707 
3708 	/* Load the checksum driver */
3709 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3710 	if (IS_ERR(sbi->s_chksum_driver)) {
3711 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3712 		ret = PTR_ERR(sbi->s_chksum_driver);
3713 		sbi->s_chksum_driver = NULL;
3714 		goto failed_mount;
3715 	}
3716 
3717 	/* Check superblock checksum */
3718 	if (!ext4_superblock_csum_verify(sb, es)) {
3719 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3720 			 "invalid superblock checksum.  Run e2fsck?");
3721 		silent = 1;
3722 		ret = -EFSBADCRC;
3723 		goto cantfind_ext4;
3724 	}
3725 
3726 	/* Precompute checksum seed for all metadata */
3727 	if (ext4_has_feature_csum_seed(sb))
3728 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3729 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3730 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3731 					       sizeof(es->s_uuid));
3732 
3733 	/* Set defaults before we parse the mount options */
3734 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3735 	set_opt(sb, INIT_INODE_TABLE);
3736 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3737 		set_opt(sb, DEBUG);
3738 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3739 		set_opt(sb, GRPID);
3740 	if (def_mount_opts & EXT4_DEFM_UID16)
3741 		set_opt(sb, NO_UID32);
3742 	/* xattr user namespace & acls are now defaulted on */
3743 	set_opt(sb, XATTR_USER);
3744 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3745 	set_opt(sb, POSIX_ACL);
3746 #endif
3747 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3748 	if (ext4_has_metadata_csum(sb))
3749 		set_opt(sb, JOURNAL_CHECKSUM);
3750 
3751 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3752 		set_opt(sb, JOURNAL_DATA);
3753 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3754 		set_opt(sb, ORDERED_DATA);
3755 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3756 		set_opt(sb, WRITEBACK_DATA);
3757 
3758 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3759 		set_opt(sb, ERRORS_PANIC);
3760 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3761 		set_opt(sb, ERRORS_CONT);
3762 	else
3763 		set_opt(sb, ERRORS_RO);
3764 	/* block_validity enabled by default; disable with noblock_validity */
3765 	set_opt(sb, BLOCK_VALIDITY);
3766 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3767 		set_opt(sb, DISCARD);
3768 
3769 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3770 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3771 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3772 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3773 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3774 
3775 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3776 		set_opt(sb, BARRIER);
3777 
3778 	/*
3779 	 * enable delayed allocation by default
3780 	 * Use -o nodelalloc to turn it off
3781 	 */
3782 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3783 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3784 		set_opt(sb, DELALLOC);
3785 
3786 	/*
3787 	 * set default s_li_wait_mult for lazyinit, for the case there is
3788 	 * no mount option specified.
3789 	 */
3790 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3791 
3792 	if (sbi->s_es->s_mount_opts[0]) {
3793 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3794 					      sizeof(sbi->s_es->s_mount_opts),
3795 					      GFP_KERNEL);
3796 		if (!s_mount_opts)
3797 			goto failed_mount;
3798 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3799 				   &journal_ioprio, 0)) {
3800 			ext4_msg(sb, KERN_WARNING,
3801 				 "failed to parse options in superblock: %s",
3802 				 s_mount_opts);
3803 		}
3804 		kfree(s_mount_opts);
3805 	}
3806 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3807 	if (!parse_options((char *) data, sb, &journal_devnum,
3808 			   &journal_ioprio, 0))
3809 		goto failed_mount;
3810 
3811 #ifdef CONFIG_UNICODE
3812 	if (ext4_has_feature_casefold(sb) && !sbi->s_encoding) {
3813 		const struct ext4_sb_encodings *encoding_info;
3814 		struct unicode_map *encoding;
3815 		__u16 encoding_flags;
3816 
3817 		if (ext4_has_feature_encrypt(sb)) {
3818 			ext4_msg(sb, KERN_ERR,
3819 				 "Can't mount with encoding and encryption");
3820 			goto failed_mount;
3821 		}
3822 
3823 		if (ext4_sb_read_encoding(es, &encoding_info,
3824 					  &encoding_flags)) {
3825 			ext4_msg(sb, KERN_ERR,
3826 				 "Encoding requested by superblock is unknown");
3827 			goto failed_mount;
3828 		}
3829 
3830 		encoding = utf8_load(encoding_info->version);
3831 		if (IS_ERR(encoding)) {
3832 			ext4_msg(sb, KERN_ERR,
3833 				 "can't mount with superblock charset: %s-%s "
3834 				 "not supported by the kernel. flags: 0x%x.",
3835 				 encoding_info->name, encoding_info->version,
3836 				 encoding_flags);
3837 			goto failed_mount;
3838 		}
3839 		ext4_msg(sb, KERN_INFO,"Using encoding defined by superblock: "
3840 			 "%s-%s with flags 0x%hx", encoding_info->name,
3841 			 encoding_info->version?:"\b", encoding_flags);
3842 
3843 		sbi->s_encoding = encoding;
3844 		sbi->s_encoding_flags = encoding_flags;
3845 	}
3846 #endif
3847 
3848 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3849 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3850 			    "with data=journal disables delayed "
3851 			    "allocation and O_DIRECT support!\n");
3852 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3853 			ext4_msg(sb, KERN_ERR, "can't mount with "
3854 				 "both data=journal and delalloc");
3855 			goto failed_mount;
3856 		}
3857 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3858 			ext4_msg(sb, KERN_ERR, "can't mount with "
3859 				 "both data=journal and dioread_nolock");
3860 			goto failed_mount;
3861 		}
3862 		if (test_opt(sb, DAX)) {
3863 			ext4_msg(sb, KERN_ERR, "can't mount with "
3864 				 "both data=journal and dax");
3865 			goto failed_mount;
3866 		}
3867 		if (ext4_has_feature_encrypt(sb)) {
3868 			ext4_msg(sb, KERN_WARNING,
3869 				 "encrypted files will use data=ordered "
3870 				 "instead of data journaling mode");
3871 		}
3872 		if (test_opt(sb, DELALLOC))
3873 			clear_opt(sb, DELALLOC);
3874 	} else {
3875 		sb->s_iflags |= SB_I_CGROUPWB;
3876 	}
3877 
3878 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3879 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3880 
3881 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3882 	    (ext4_has_compat_features(sb) ||
3883 	     ext4_has_ro_compat_features(sb) ||
3884 	     ext4_has_incompat_features(sb)))
3885 		ext4_msg(sb, KERN_WARNING,
3886 		       "feature flags set on rev 0 fs, "
3887 		       "running e2fsck is recommended");
3888 
3889 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3890 		set_opt2(sb, HURD_COMPAT);
3891 		if (ext4_has_feature_64bit(sb)) {
3892 			ext4_msg(sb, KERN_ERR,
3893 				 "The Hurd can't support 64-bit file systems");
3894 			goto failed_mount;
3895 		}
3896 
3897 		/*
3898 		 * ea_inode feature uses l_i_version field which is not
3899 		 * available in HURD_COMPAT mode.
3900 		 */
3901 		if (ext4_has_feature_ea_inode(sb)) {
3902 			ext4_msg(sb, KERN_ERR,
3903 				 "ea_inode feature is not supported for Hurd");
3904 			goto failed_mount;
3905 		}
3906 	}
3907 
3908 	if (IS_EXT2_SB(sb)) {
3909 		if (ext2_feature_set_ok(sb))
3910 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3911 				 "using the ext4 subsystem");
3912 		else {
3913 			/*
3914 			 * If we're probing be silent, if this looks like
3915 			 * it's actually an ext[34] filesystem.
3916 			 */
3917 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3918 				goto failed_mount;
3919 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3920 				 "to feature incompatibilities");
3921 			goto failed_mount;
3922 		}
3923 	}
3924 
3925 	if (IS_EXT3_SB(sb)) {
3926 		if (ext3_feature_set_ok(sb))
3927 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3928 				 "using the ext4 subsystem");
3929 		else {
3930 			/*
3931 			 * If we're probing be silent, if this looks like
3932 			 * it's actually an ext4 filesystem.
3933 			 */
3934 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3935 				goto failed_mount;
3936 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3937 				 "to feature incompatibilities");
3938 			goto failed_mount;
3939 		}
3940 	}
3941 
3942 	/*
3943 	 * Check feature flags regardless of the revision level, since we
3944 	 * previously didn't change the revision level when setting the flags,
3945 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3946 	 */
3947 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3948 		goto failed_mount;
3949 
3950 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3951 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3952 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3953 		ext4_msg(sb, KERN_ERR,
3954 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3955 			 blocksize, le32_to_cpu(es->s_log_block_size));
3956 		goto failed_mount;
3957 	}
3958 	if (le32_to_cpu(es->s_log_block_size) >
3959 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3960 		ext4_msg(sb, KERN_ERR,
3961 			 "Invalid log block size: %u",
3962 			 le32_to_cpu(es->s_log_block_size));
3963 		goto failed_mount;
3964 	}
3965 	if (le32_to_cpu(es->s_log_cluster_size) >
3966 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3967 		ext4_msg(sb, KERN_ERR,
3968 			 "Invalid log cluster size: %u",
3969 			 le32_to_cpu(es->s_log_cluster_size));
3970 		goto failed_mount;
3971 	}
3972 
3973 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3974 		ext4_msg(sb, KERN_ERR,
3975 			 "Number of reserved GDT blocks insanely large: %d",
3976 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3977 		goto failed_mount;
3978 	}
3979 
3980 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3981 		if (ext4_has_feature_inline_data(sb)) {
3982 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3983 					" that may contain inline data");
3984 			goto failed_mount;
3985 		}
3986 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3987 			ext4_msg(sb, KERN_ERR,
3988 				"DAX unsupported by block device.");
3989 			goto failed_mount;
3990 		}
3991 	}
3992 
3993 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3994 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3995 			 es->s_encryption_level);
3996 		goto failed_mount;
3997 	}
3998 
3999 	if (sb->s_blocksize != blocksize) {
4000 		/* Validate the filesystem blocksize */
4001 		if (!sb_set_blocksize(sb, blocksize)) {
4002 			ext4_msg(sb, KERN_ERR, "bad block size %d",
4003 					blocksize);
4004 			goto failed_mount;
4005 		}
4006 
4007 		brelse(bh);
4008 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
4009 		offset = do_div(logical_sb_block, blocksize);
4010 		bh = sb_bread_unmovable(sb, logical_sb_block);
4011 		if (!bh) {
4012 			ext4_msg(sb, KERN_ERR,
4013 			       "Can't read superblock on 2nd try");
4014 			goto failed_mount;
4015 		}
4016 		es = (struct ext4_super_block *)(bh->b_data + offset);
4017 		sbi->s_es = es;
4018 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
4019 			ext4_msg(sb, KERN_ERR,
4020 			       "Magic mismatch, very weird!");
4021 			goto failed_mount;
4022 		}
4023 	}
4024 
4025 	has_huge_files = ext4_has_feature_huge_file(sb);
4026 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
4027 						      has_huge_files);
4028 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
4029 
4030 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
4031 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
4032 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
4033 	} else {
4034 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
4035 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
4036 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
4037 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
4038 				 sbi->s_first_ino);
4039 			goto failed_mount;
4040 		}
4041 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
4042 		    (!is_power_of_2(sbi->s_inode_size)) ||
4043 		    (sbi->s_inode_size > blocksize)) {
4044 			ext4_msg(sb, KERN_ERR,
4045 			       "unsupported inode size: %d",
4046 			       sbi->s_inode_size);
4047 			goto failed_mount;
4048 		}
4049 		/*
4050 		 * i_atime_extra is the last extra field available for [acm]times in
4051 		 * struct ext4_inode. Checking for that field should suffice to ensure
4052 		 * we have extra space for all three.
4053 		 */
4054 		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
4055 			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
4056 			sb->s_time_gran = 1;
4057 			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
4058 		} else {
4059 			sb->s_time_gran = NSEC_PER_SEC;
4060 			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
4061 		}
4062 
4063 		sb->s_time_min = EXT4_TIMESTAMP_MIN;
4064 	}
4065 
4066 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
4067 	if (ext4_has_feature_64bit(sb)) {
4068 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
4069 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
4070 		    !is_power_of_2(sbi->s_desc_size)) {
4071 			ext4_msg(sb, KERN_ERR,
4072 			       "unsupported descriptor size %lu",
4073 			       sbi->s_desc_size);
4074 			goto failed_mount;
4075 		}
4076 	} else
4077 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
4078 
4079 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
4080 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
4081 
4082 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
4083 	if (sbi->s_inodes_per_block == 0)
4084 		goto cantfind_ext4;
4085 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
4086 	    sbi->s_inodes_per_group > blocksize * 8) {
4087 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
4088 			 sbi->s_blocks_per_group);
4089 		goto failed_mount;
4090 	}
4091 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
4092 					sbi->s_inodes_per_block;
4093 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
4094 	sbi->s_sbh = bh;
4095 	sbi->s_mount_state = le16_to_cpu(es->s_state);
4096 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
4097 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
4098 
4099 	for (i = 0; i < 4; i++)
4100 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
4101 	sbi->s_def_hash_version = es->s_def_hash_version;
4102 	if (ext4_has_feature_dir_index(sb)) {
4103 		i = le32_to_cpu(es->s_flags);
4104 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
4105 			sbi->s_hash_unsigned = 3;
4106 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
4107 #ifdef __CHAR_UNSIGNED__
4108 			if (!sb_rdonly(sb))
4109 				es->s_flags |=
4110 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
4111 			sbi->s_hash_unsigned = 3;
4112 #else
4113 			if (!sb_rdonly(sb))
4114 				es->s_flags |=
4115 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
4116 #endif
4117 		}
4118 	}
4119 
4120 	/* Handle clustersize */
4121 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
4122 	has_bigalloc = ext4_has_feature_bigalloc(sb);
4123 	if (has_bigalloc) {
4124 		if (clustersize < blocksize) {
4125 			ext4_msg(sb, KERN_ERR,
4126 				 "cluster size (%d) smaller than "
4127 				 "block size (%d)", clustersize, blocksize);
4128 			goto failed_mount;
4129 		}
4130 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4131 			le32_to_cpu(es->s_log_block_size);
4132 		sbi->s_clusters_per_group =
4133 			le32_to_cpu(es->s_clusters_per_group);
4134 		if (sbi->s_clusters_per_group > blocksize * 8) {
4135 			ext4_msg(sb, KERN_ERR,
4136 				 "#clusters per group too big: %lu",
4137 				 sbi->s_clusters_per_group);
4138 			goto failed_mount;
4139 		}
4140 		if (sbi->s_blocks_per_group !=
4141 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4142 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4143 				 "clusters per group (%lu) inconsistent",
4144 				 sbi->s_blocks_per_group,
4145 				 sbi->s_clusters_per_group);
4146 			goto failed_mount;
4147 		}
4148 	} else {
4149 		if (clustersize != blocksize) {
4150 			ext4_msg(sb, KERN_ERR,
4151 				 "fragment/cluster size (%d) != "
4152 				 "block size (%d)", clustersize, blocksize);
4153 			goto failed_mount;
4154 		}
4155 		if (sbi->s_blocks_per_group > blocksize * 8) {
4156 			ext4_msg(sb, KERN_ERR,
4157 				 "#blocks per group too big: %lu",
4158 				 sbi->s_blocks_per_group);
4159 			goto failed_mount;
4160 		}
4161 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4162 		sbi->s_cluster_bits = 0;
4163 	}
4164 	sbi->s_cluster_ratio = clustersize / blocksize;
4165 
4166 	/* Do we have standard group size of clustersize * 8 blocks ? */
4167 	if (sbi->s_blocks_per_group == clustersize << 3)
4168 		set_opt2(sb, STD_GROUP_SIZE);
4169 
4170 	/*
4171 	 * Test whether we have more sectors than will fit in sector_t,
4172 	 * and whether the max offset is addressable by the page cache.
4173 	 */
4174 	err = generic_check_addressable(sb->s_blocksize_bits,
4175 					ext4_blocks_count(es));
4176 	if (err) {
4177 		ext4_msg(sb, KERN_ERR, "filesystem"
4178 			 " too large to mount safely on this system");
4179 		goto failed_mount;
4180 	}
4181 
4182 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4183 		goto cantfind_ext4;
4184 
4185 	/* check blocks count against device size */
4186 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4187 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4188 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4189 		       "exceeds size of device (%llu blocks)",
4190 		       ext4_blocks_count(es), blocks_count);
4191 		goto failed_mount;
4192 	}
4193 
4194 	/*
4195 	 * It makes no sense for the first data block to be beyond the end
4196 	 * of the filesystem.
4197 	 */
4198 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4199 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4200 			 "block %u is beyond end of filesystem (%llu)",
4201 			 le32_to_cpu(es->s_first_data_block),
4202 			 ext4_blocks_count(es));
4203 		goto failed_mount;
4204 	}
4205 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4206 	    (sbi->s_cluster_ratio == 1)) {
4207 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4208 			 "block is 0 with a 1k block and cluster size");
4209 		goto failed_mount;
4210 	}
4211 
4212 	blocks_count = (ext4_blocks_count(es) -
4213 			le32_to_cpu(es->s_first_data_block) +
4214 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4215 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4216 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4217 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4218 		       "(block count %llu, first data block %u, "
4219 		       "blocks per group %lu)", sbi->s_groups_count,
4220 		       ext4_blocks_count(es),
4221 		       le32_to_cpu(es->s_first_data_block),
4222 		       EXT4_BLOCKS_PER_GROUP(sb));
4223 		goto failed_mount;
4224 	}
4225 	sbi->s_groups_count = blocks_count;
4226 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4227 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4228 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4229 	    le32_to_cpu(es->s_inodes_count)) {
4230 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4231 			 le32_to_cpu(es->s_inodes_count),
4232 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4233 		ret = -EINVAL;
4234 		goto failed_mount;
4235 	}
4236 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4237 		   EXT4_DESC_PER_BLOCK(sb);
4238 	if (ext4_has_feature_meta_bg(sb)) {
4239 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4240 			ext4_msg(sb, KERN_WARNING,
4241 				 "first meta block group too large: %u "
4242 				 "(group descriptor block count %u)",
4243 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4244 			goto failed_mount;
4245 		}
4246 	}
4247 	sbi->s_group_desc = kvmalloc_array(db_count,
4248 					   sizeof(struct buffer_head *),
4249 					   GFP_KERNEL);
4250 	if (sbi->s_group_desc == NULL) {
4251 		ext4_msg(sb, KERN_ERR, "not enough memory");
4252 		ret = -ENOMEM;
4253 		goto failed_mount;
4254 	}
4255 
4256 	bgl_lock_init(sbi->s_blockgroup_lock);
4257 
4258 	/* Pre-read the descriptors into the buffer cache */
4259 	for (i = 0; i < db_count; i++) {
4260 		block = descriptor_loc(sb, logical_sb_block, i);
4261 		sb_breadahead(sb, block);
4262 	}
4263 
4264 	for (i = 0; i < db_count; i++) {
4265 		block = descriptor_loc(sb, logical_sb_block, i);
4266 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4267 		if (!sbi->s_group_desc[i]) {
4268 			ext4_msg(sb, KERN_ERR,
4269 			       "can't read group descriptor %d", i);
4270 			db_count = i;
4271 			goto failed_mount2;
4272 		}
4273 	}
4274 	sbi->s_gdb_count = db_count;
4275 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4276 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4277 		ret = -EFSCORRUPTED;
4278 		goto failed_mount2;
4279 	}
4280 
4281 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4282 
4283 	/* Register extent status tree shrinker */
4284 	if (ext4_es_register_shrinker(sbi))
4285 		goto failed_mount3;
4286 
4287 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4288 	sbi->s_extent_max_zeroout_kb = 32;
4289 
4290 	/*
4291 	 * set up enough so that it can read an inode
4292 	 */
4293 	sb->s_op = &ext4_sops;
4294 	sb->s_export_op = &ext4_export_ops;
4295 	sb->s_xattr = ext4_xattr_handlers;
4296 #ifdef CONFIG_FS_ENCRYPTION
4297 	sb->s_cop = &ext4_cryptops;
4298 #endif
4299 #ifdef CONFIG_FS_VERITY
4300 	sb->s_vop = &ext4_verityops;
4301 #endif
4302 #ifdef CONFIG_QUOTA
4303 	sb->dq_op = &ext4_quota_operations;
4304 	if (ext4_has_feature_quota(sb))
4305 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4306 	else
4307 		sb->s_qcop = &ext4_qctl_operations;
4308 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4309 #endif
4310 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4311 
4312 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4313 	mutex_init(&sbi->s_orphan_lock);
4314 
4315 	sb->s_root = NULL;
4316 
4317 	needs_recovery = (es->s_last_orphan != 0 ||
4318 			  ext4_has_feature_journal_needs_recovery(sb));
4319 
4320 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4321 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4322 			goto failed_mount3a;
4323 
4324 	/*
4325 	 * The first inode we look at is the journal inode.  Don't try
4326 	 * root first: it may be modified in the journal!
4327 	 */
4328 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4329 		err = ext4_load_journal(sb, es, journal_devnum);
4330 		if (err)
4331 			goto failed_mount3a;
4332 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4333 		   ext4_has_feature_journal_needs_recovery(sb)) {
4334 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4335 		       "suppressed and not mounted read-only");
4336 		goto failed_mount_wq;
4337 	} else {
4338 		/* Nojournal mode, all journal mount options are illegal */
4339 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4340 			ext4_msg(sb, KERN_ERR, "can't mount with "
4341 				 "journal_checksum, fs mounted w/o journal");
4342 			goto failed_mount_wq;
4343 		}
4344 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4345 			ext4_msg(sb, KERN_ERR, "can't mount with "
4346 				 "journal_async_commit, fs mounted w/o journal");
4347 			goto failed_mount_wq;
4348 		}
4349 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4350 			ext4_msg(sb, KERN_ERR, "can't mount with "
4351 				 "commit=%lu, fs mounted w/o journal",
4352 				 sbi->s_commit_interval / HZ);
4353 			goto failed_mount_wq;
4354 		}
4355 		if (EXT4_MOUNT_DATA_FLAGS &
4356 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4357 			ext4_msg(sb, KERN_ERR, "can't mount with "
4358 				 "data=, fs mounted w/o journal");
4359 			goto failed_mount_wq;
4360 		}
4361 		sbi->s_def_mount_opt &= ~EXT4_MOUNT_JOURNAL_CHECKSUM;
4362 		clear_opt(sb, JOURNAL_CHECKSUM);
4363 		clear_opt(sb, DATA_FLAGS);
4364 		sbi->s_journal = NULL;
4365 		needs_recovery = 0;
4366 		goto no_journal;
4367 	}
4368 
4369 	if (ext4_has_feature_64bit(sb) &&
4370 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4371 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4372 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4373 		goto failed_mount_wq;
4374 	}
4375 
4376 	if (!set_journal_csum_feature_set(sb)) {
4377 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4378 			 "feature set");
4379 		goto failed_mount_wq;
4380 	}
4381 
4382 	/* We have now updated the journal if required, so we can
4383 	 * validate the data journaling mode. */
4384 	switch (test_opt(sb, DATA_FLAGS)) {
4385 	case 0:
4386 		/* No mode set, assume a default based on the journal
4387 		 * capabilities: ORDERED_DATA if the journal can
4388 		 * cope, else JOURNAL_DATA
4389 		 */
4390 		if (jbd2_journal_check_available_features
4391 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4392 			set_opt(sb, ORDERED_DATA);
4393 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4394 		} else {
4395 			set_opt(sb, JOURNAL_DATA);
4396 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4397 		}
4398 		break;
4399 
4400 	case EXT4_MOUNT_ORDERED_DATA:
4401 	case EXT4_MOUNT_WRITEBACK_DATA:
4402 		if (!jbd2_journal_check_available_features
4403 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4404 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4405 			       "requested data journaling mode");
4406 			goto failed_mount_wq;
4407 		}
4408 	default:
4409 		break;
4410 	}
4411 
4412 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4413 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4414 		ext4_msg(sb, KERN_ERR, "can't mount with "
4415 			"journal_async_commit in data=ordered mode");
4416 		goto failed_mount_wq;
4417 	}
4418 
4419 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4420 
4421 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4422 
4423 no_journal:
4424 	if (!test_opt(sb, NO_MBCACHE)) {
4425 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4426 		if (!sbi->s_ea_block_cache) {
4427 			ext4_msg(sb, KERN_ERR,
4428 				 "Failed to create ea_block_cache");
4429 			goto failed_mount_wq;
4430 		}
4431 
4432 		if (ext4_has_feature_ea_inode(sb)) {
4433 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4434 			if (!sbi->s_ea_inode_cache) {
4435 				ext4_msg(sb, KERN_ERR,
4436 					 "Failed to create ea_inode_cache");
4437 				goto failed_mount_wq;
4438 			}
4439 		}
4440 	}
4441 
4442 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4443 	    (blocksize != PAGE_SIZE)) {
4444 		ext4_msg(sb, KERN_ERR,
4445 			 "Unsupported blocksize for fs encryption");
4446 		goto failed_mount_wq;
4447 	}
4448 
4449 	if (ext4_has_feature_verity(sb) && blocksize != PAGE_SIZE) {
4450 		ext4_msg(sb, KERN_ERR, "Unsupported blocksize for fs-verity");
4451 		goto failed_mount_wq;
4452 	}
4453 
4454 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4455 	    !ext4_has_feature_encrypt(sb)) {
4456 		ext4_set_feature_encrypt(sb);
4457 		ext4_commit_super(sb, 1);
4458 	}
4459 
4460 	/*
4461 	 * Get the # of file system overhead blocks from the
4462 	 * superblock if present.
4463 	 */
4464 	if (es->s_overhead_clusters)
4465 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4466 	else {
4467 		err = ext4_calculate_overhead(sb);
4468 		if (err)
4469 			goto failed_mount_wq;
4470 	}
4471 
4472 	/*
4473 	 * The maximum number of concurrent works can be high and
4474 	 * concurrency isn't really necessary.  Limit it to 1.
4475 	 */
4476 	EXT4_SB(sb)->rsv_conversion_wq =
4477 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4478 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4479 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4480 		ret = -ENOMEM;
4481 		goto failed_mount4;
4482 	}
4483 
4484 	/*
4485 	 * The jbd2_journal_load will have done any necessary log recovery,
4486 	 * so we can safely mount the rest of the filesystem now.
4487 	 */
4488 
4489 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4490 	if (IS_ERR(root)) {
4491 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4492 		ret = PTR_ERR(root);
4493 		root = NULL;
4494 		goto failed_mount4;
4495 	}
4496 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4497 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4498 		iput(root);
4499 		goto failed_mount4;
4500 	}
4501 
4502 #ifdef CONFIG_UNICODE
4503 	if (sbi->s_encoding)
4504 		sb->s_d_op = &ext4_dentry_ops;
4505 #endif
4506 
4507 	sb->s_root = d_make_root(root);
4508 	if (!sb->s_root) {
4509 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4510 		ret = -ENOMEM;
4511 		goto failed_mount4;
4512 	}
4513 
4514 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4515 	if (ret == -EROFS) {
4516 		sb->s_flags |= SB_RDONLY;
4517 		ret = 0;
4518 	} else if (ret)
4519 		goto failed_mount4a;
4520 
4521 	ext4_clamp_want_extra_isize(sb);
4522 
4523 	ext4_set_resv_clusters(sb);
4524 
4525 	err = ext4_setup_system_zone(sb);
4526 	if (err) {
4527 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4528 			 "zone (%d)", err);
4529 		goto failed_mount4a;
4530 	}
4531 
4532 	ext4_ext_init(sb);
4533 	err = ext4_mb_init(sb);
4534 	if (err) {
4535 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4536 			 err);
4537 		goto failed_mount5;
4538 	}
4539 
4540 	block = ext4_count_free_clusters(sb);
4541 	ext4_free_blocks_count_set(sbi->s_es,
4542 				   EXT4_C2B(sbi, block));
4543 	ext4_superblock_csum_set(sb);
4544 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4545 				  GFP_KERNEL);
4546 	if (!err) {
4547 		unsigned long freei = ext4_count_free_inodes(sb);
4548 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4549 		ext4_superblock_csum_set(sb);
4550 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4551 					  GFP_KERNEL);
4552 	}
4553 	if (!err)
4554 		err = percpu_counter_init(&sbi->s_dirs_counter,
4555 					  ext4_count_dirs(sb), GFP_KERNEL);
4556 	if (!err)
4557 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4558 					  GFP_KERNEL);
4559 	if (!err)
4560 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4561 
4562 	if (err) {
4563 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4564 		goto failed_mount6;
4565 	}
4566 
4567 	if (ext4_has_feature_flex_bg(sb))
4568 		if (!ext4_fill_flex_info(sb)) {
4569 			ext4_msg(sb, KERN_ERR,
4570 			       "unable to initialize "
4571 			       "flex_bg meta info!");
4572 			goto failed_mount6;
4573 		}
4574 
4575 	err = ext4_register_li_request(sb, first_not_zeroed);
4576 	if (err)
4577 		goto failed_mount6;
4578 
4579 	err = ext4_register_sysfs(sb);
4580 	if (err)
4581 		goto failed_mount7;
4582 
4583 #ifdef CONFIG_QUOTA
4584 	/* Enable quota usage during mount. */
4585 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4586 		err = ext4_enable_quotas(sb);
4587 		if (err)
4588 			goto failed_mount8;
4589 	}
4590 #endif  /* CONFIG_QUOTA */
4591 
4592 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4593 	ext4_orphan_cleanup(sb, es);
4594 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4595 	if (needs_recovery) {
4596 		ext4_msg(sb, KERN_INFO, "recovery complete");
4597 		ext4_mark_recovery_complete(sb, es);
4598 	}
4599 	if (EXT4_SB(sb)->s_journal) {
4600 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4601 			descr = " journalled data mode";
4602 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4603 			descr = " ordered data mode";
4604 		else
4605 			descr = " writeback data mode";
4606 	} else
4607 		descr = "out journal";
4608 
4609 	if (test_opt(sb, DISCARD)) {
4610 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4611 		if (!blk_queue_discard(q))
4612 			ext4_msg(sb, KERN_WARNING,
4613 				 "mounting with \"discard\" option, but "
4614 				 "the device does not support discard");
4615 	}
4616 
4617 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4618 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4619 			 "Opts: %.*s%s%s", descr,
4620 			 (int) sizeof(sbi->s_es->s_mount_opts),
4621 			 sbi->s_es->s_mount_opts,
4622 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4623 
4624 	if (es->s_error_count)
4625 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4626 
4627 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4628 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4629 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4630 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4631 
4632 	kfree(orig_data);
4633 	return 0;
4634 
4635 cantfind_ext4:
4636 	if (!silent)
4637 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4638 	goto failed_mount;
4639 
4640 #ifdef CONFIG_QUOTA
4641 failed_mount8:
4642 	ext4_unregister_sysfs(sb);
4643 #endif
4644 failed_mount7:
4645 	ext4_unregister_li_request(sb);
4646 failed_mount6:
4647 	ext4_mb_release(sb);
4648 	if (sbi->s_flex_groups)
4649 		kvfree(sbi->s_flex_groups);
4650 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4651 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4652 	percpu_counter_destroy(&sbi->s_dirs_counter);
4653 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4654 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4655 failed_mount5:
4656 	ext4_ext_release(sb);
4657 	ext4_release_system_zone(sb);
4658 failed_mount4a:
4659 	dput(sb->s_root);
4660 	sb->s_root = NULL;
4661 failed_mount4:
4662 	ext4_msg(sb, KERN_ERR, "mount failed");
4663 	if (EXT4_SB(sb)->rsv_conversion_wq)
4664 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4665 failed_mount_wq:
4666 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4667 	sbi->s_ea_inode_cache = NULL;
4668 
4669 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4670 	sbi->s_ea_block_cache = NULL;
4671 
4672 	if (sbi->s_journal) {
4673 		jbd2_journal_destroy(sbi->s_journal);
4674 		sbi->s_journal = NULL;
4675 	}
4676 failed_mount3a:
4677 	ext4_es_unregister_shrinker(sbi);
4678 failed_mount3:
4679 	del_timer_sync(&sbi->s_err_report);
4680 	if (sbi->s_mmp_tsk)
4681 		kthread_stop(sbi->s_mmp_tsk);
4682 failed_mount2:
4683 	for (i = 0; i < db_count; i++)
4684 		brelse(sbi->s_group_desc[i]);
4685 	kvfree(sbi->s_group_desc);
4686 failed_mount:
4687 	if (sbi->s_chksum_driver)
4688 		crypto_free_shash(sbi->s_chksum_driver);
4689 
4690 #ifdef CONFIG_UNICODE
4691 	utf8_unload(sbi->s_encoding);
4692 #endif
4693 
4694 #ifdef CONFIG_QUOTA
4695 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4696 		kfree(get_qf_name(sb, sbi, i));
4697 #endif
4698 	ext4_blkdev_remove(sbi);
4699 	brelse(bh);
4700 out_fail:
4701 	sb->s_fs_info = NULL;
4702 	kfree(sbi->s_blockgroup_lock);
4703 out_free_base:
4704 	kfree(sbi);
4705 	kfree(orig_data);
4706 	fs_put_dax(dax_dev);
4707 	return err ? err : ret;
4708 }
4709 
4710 /*
4711  * Setup any per-fs journal parameters now.  We'll do this both on
4712  * initial mount, once the journal has been initialised but before we've
4713  * done any recovery; and again on any subsequent remount.
4714  */
4715 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4716 {
4717 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4718 
4719 	journal->j_commit_interval = sbi->s_commit_interval;
4720 	journal->j_min_batch_time = sbi->s_min_batch_time;
4721 	journal->j_max_batch_time = sbi->s_max_batch_time;
4722 
4723 	write_lock(&journal->j_state_lock);
4724 	if (test_opt(sb, BARRIER))
4725 		journal->j_flags |= JBD2_BARRIER;
4726 	else
4727 		journal->j_flags &= ~JBD2_BARRIER;
4728 	if (test_opt(sb, DATA_ERR_ABORT))
4729 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4730 	else
4731 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4732 	write_unlock(&journal->j_state_lock);
4733 }
4734 
4735 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4736 					     unsigned int journal_inum)
4737 {
4738 	struct inode *journal_inode;
4739 
4740 	/*
4741 	 * Test for the existence of a valid inode on disk.  Bad things
4742 	 * happen if we iget() an unused inode, as the subsequent iput()
4743 	 * will try to delete it.
4744 	 */
4745 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4746 	if (IS_ERR(journal_inode)) {
4747 		ext4_msg(sb, KERN_ERR, "no journal found");
4748 		return NULL;
4749 	}
4750 	if (!journal_inode->i_nlink) {
4751 		make_bad_inode(journal_inode);
4752 		iput(journal_inode);
4753 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4754 		return NULL;
4755 	}
4756 
4757 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4758 		  journal_inode, journal_inode->i_size);
4759 	if (!S_ISREG(journal_inode->i_mode)) {
4760 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4761 		iput(journal_inode);
4762 		return NULL;
4763 	}
4764 	return journal_inode;
4765 }
4766 
4767 static journal_t *ext4_get_journal(struct super_block *sb,
4768 				   unsigned int journal_inum)
4769 {
4770 	struct inode *journal_inode;
4771 	journal_t *journal;
4772 
4773 	BUG_ON(!ext4_has_feature_journal(sb));
4774 
4775 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4776 	if (!journal_inode)
4777 		return NULL;
4778 
4779 	journal = jbd2_journal_init_inode(journal_inode);
4780 	if (!journal) {
4781 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4782 		iput(journal_inode);
4783 		return NULL;
4784 	}
4785 	journal->j_private = sb;
4786 	ext4_init_journal_params(sb, journal);
4787 	return journal;
4788 }
4789 
4790 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4791 				       dev_t j_dev)
4792 {
4793 	struct buffer_head *bh;
4794 	journal_t *journal;
4795 	ext4_fsblk_t start;
4796 	ext4_fsblk_t len;
4797 	int hblock, blocksize;
4798 	ext4_fsblk_t sb_block;
4799 	unsigned long offset;
4800 	struct ext4_super_block *es;
4801 	struct block_device *bdev;
4802 
4803 	BUG_ON(!ext4_has_feature_journal(sb));
4804 
4805 	bdev = ext4_blkdev_get(j_dev, sb);
4806 	if (bdev == NULL)
4807 		return NULL;
4808 
4809 	blocksize = sb->s_blocksize;
4810 	hblock = bdev_logical_block_size(bdev);
4811 	if (blocksize < hblock) {
4812 		ext4_msg(sb, KERN_ERR,
4813 			"blocksize too small for journal device");
4814 		goto out_bdev;
4815 	}
4816 
4817 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4818 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4819 	set_blocksize(bdev, blocksize);
4820 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4821 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4822 		       "external journal");
4823 		goto out_bdev;
4824 	}
4825 
4826 	es = (struct ext4_super_block *) (bh->b_data + offset);
4827 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4828 	    !(le32_to_cpu(es->s_feature_incompat) &
4829 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4830 		ext4_msg(sb, KERN_ERR, "external journal has "
4831 					"bad superblock");
4832 		brelse(bh);
4833 		goto out_bdev;
4834 	}
4835 
4836 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4837 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4838 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4839 		ext4_msg(sb, KERN_ERR, "external journal has "
4840 				       "corrupt superblock");
4841 		brelse(bh);
4842 		goto out_bdev;
4843 	}
4844 
4845 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4846 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4847 		brelse(bh);
4848 		goto out_bdev;
4849 	}
4850 
4851 	len = ext4_blocks_count(es);
4852 	start = sb_block + 1;
4853 	brelse(bh);	/* we're done with the superblock */
4854 
4855 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4856 					start, len, blocksize);
4857 	if (!journal) {
4858 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4859 		goto out_bdev;
4860 	}
4861 	journal->j_private = sb;
4862 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4863 	wait_on_buffer(journal->j_sb_buffer);
4864 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4865 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4866 		goto out_journal;
4867 	}
4868 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4869 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4870 					"user (unsupported) - %d",
4871 			be32_to_cpu(journal->j_superblock->s_nr_users));
4872 		goto out_journal;
4873 	}
4874 	EXT4_SB(sb)->journal_bdev = bdev;
4875 	ext4_init_journal_params(sb, journal);
4876 	return journal;
4877 
4878 out_journal:
4879 	jbd2_journal_destroy(journal);
4880 out_bdev:
4881 	ext4_blkdev_put(bdev);
4882 	return NULL;
4883 }
4884 
4885 static int ext4_load_journal(struct super_block *sb,
4886 			     struct ext4_super_block *es,
4887 			     unsigned long journal_devnum)
4888 {
4889 	journal_t *journal;
4890 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4891 	dev_t journal_dev;
4892 	int err = 0;
4893 	int really_read_only;
4894 
4895 	BUG_ON(!ext4_has_feature_journal(sb));
4896 
4897 	if (journal_devnum &&
4898 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4899 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4900 			"numbers have changed");
4901 		journal_dev = new_decode_dev(journal_devnum);
4902 	} else
4903 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4904 
4905 	really_read_only = bdev_read_only(sb->s_bdev);
4906 
4907 	/*
4908 	 * Are we loading a blank journal or performing recovery after a
4909 	 * crash?  For recovery, we need to check in advance whether we
4910 	 * can get read-write access to the device.
4911 	 */
4912 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4913 		if (sb_rdonly(sb)) {
4914 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4915 					"required on readonly filesystem");
4916 			if (really_read_only) {
4917 				ext4_msg(sb, KERN_ERR, "write access "
4918 					"unavailable, cannot proceed "
4919 					"(try mounting with noload)");
4920 				return -EROFS;
4921 			}
4922 			ext4_msg(sb, KERN_INFO, "write access will "
4923 			       "be enabled during recovery");
4924 		}
4925 	}
4926 
4927 	if (journal_inum && journal_dev) {
4928 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4929 		       "and inode journals!");
4930 		return -EINVAL;
4931 	}
4932 
4933 	if (journal_inum) {
4934 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4935 			return -EINVAL;
4936 	} else {
4937 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4938 			return -EINVAL;
4939 	}
4940 
4941 	if (!(journal->j_flags & JBD2_BARRIER))
4942 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4943 
4944 	if (!ext4_has_feature_journal_needs_recovery(sb))
4945 		err = jbd2_journal_wipe(journal, !really_read_only);
4946 	if (!err) {
4947 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4948 		if (save)
4949 			memcpy(save, ((char *) es) +
4950 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4951 		err = jbd2_journal_load(journal);
4952 		if (save)
4953 			memcpy(((char *) es) + EXT4_S_ERR_START,
4954 			       save, EXT4_S_ERR_LEN);
4955 		kfree(save);
4956 	}
4957 
4958 	if (err) {
4959 		ext4_msg(sb, KERN_ERR, "error loading journal");
4960 		jbd2_journal_destroy(journal);
4961 		return err;
4962 	}
4963 
4964 	EXT4_SB(sb)->s_journal = journal;
4965 	ext4_clear_journal_err(sb, es);
4966 
4967 	if (!really_read_only && journal_devnum &&
4968 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4969 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4970 
4971 		/* Make sure we flush the recovery flag to disk. */
4972 		ext4_commit_super(sb, 1);
4973 	}
4974 
4975 	return 0;
4976 }
4977 
4978 static int ext4_commit_super(struct super_block *sb, int sync)
4979 {
4980 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4981 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4982 	int error = 0;
4983 
4984 	if (!sbh || block_device_ejected(sb))
4985 		return error;
4986 
4987 	/*
4988 	 * The superblock bh should be mapped, but it might not be if the
4989 	 * device was hot-removed. Not much we can do but fail the I/O.
4990 	 */
4991 	if (!buffer_mapped(sbh))
4992 		return error;
4993 
4994 	/*
4995 	 * If the file system is mounted read-only, don't update the
4996 	 * superblock write time.  This avoids updating the superblock
4997 	 * write time when we are mounting the root file system
4998 	 * read/only but we need to replay the journal; at that point,
4999 	 * for people who are east of GMT and who make their clock
5000 	 * tick in localtime for Windows bug-for-bug compatibility,
5001 	 * the clock is set in the future, and this will cause e2fsck
5002 	 * to complain and force a full file system check.
5003 	 */
5004 	if (!(sb->s_flags & SB_RDONLY))
5005 		ext4_update_tstamp(es, s_wtime);
5006 	if (sb->s_bdev->bd_part)
5007 		es->s_kbytes_written =
5008 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
5009 			    ((part_stat_read(sb->s_bdev->bd_part,
5010 					     sectors[STAT_WRITE]) -
5011 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
5012 	else
5013 		es->s_kbytes_written =
5014 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
5015 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
5016 		ext4_free_blocks_count_set(es,
5017 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
5018 				&EXT4_SB(sb)->s_freeclusters_counter)));
5019 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
5020 		es->s_free_inodes_count =
5021 			cpu_to_le32(percpu_counter_sum_positive(
5022 				&EXT4_SB(sb)->s_freeinodes_counter));
5023 	BUFFER_TRACE(sbh, "marking dirty");
5024 	ext4_superblock_csum_set(sb);
5025 	if (sync)
5026 		lock_buffer(sbh);
5027 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
5028 		/*
5029 		 * Oh, dear.  A previous attempt to write the
5030 		 * superblock failed.  This could happen because the
5031 		 * USB device was yanked out.  Or it could happen to
5032 		 * be a transient write error and maybe the block will
5033 		 * be remapped.  Nothing we can do but to retry the
5034 		 * write and hope for the best.
5035 		 */
5036 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
5037 		       "superblock detected");
5038 		clear_buffer_write_io_error(sbh);
5039 		set_buffer_uptodate(sbh);
5040 	}
5041 	mark_buffer_dirty(sbh);
5042 	if (sync) {
5043 		unlock_buffer(sbh);
5044 		error = __sync_dirty_buffer(sbh,
5045 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
5046 		if (buffer_write_io_error(sbh)) {
5047 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
5048 			       "superblock");
5049 			clear_buffer_write_io_error(sbh);
5050 			set_buffer_uptodate(sbh);
5051 		}
5052 	}
5053 	return error;
5054 }
5055 
5056 /*
5057  * Have we just finished recovery?  If so, and if we are mounting (or
5058  * remounting) the filesystem readonly, then we will end up with a
5059  * consistent fs on disk.  Record that fact.
5060  */
5061 static void ext4_mark_recovery_complete(struct super_block *sb,
5062 					struct ext4_super_block *es)
5063 {
5064 	journal_t *journal = EXT4_SB(sb)->s_journal;
5065 
5066 	if (!ext4_has_feature_journal(sb)) {
5067 		BUG_ON(journal != NULL);
5068 		return;
5069 	}
5070 	jbd2_journal_lock_updates(journal);
5071 	if (jbd2_journal_flush(journal) < 0)
5072 		goto out;
5073 
5074 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
5075 		ext4_clear_feature_journal_needs_recovery(sb);
5076 		ext4_commit_super(sb, 1);
5077 	}
5078 
5079 out:
5080 	jbd2_journal_unlock_updates(journal);
5081 }
5082 
5083 /*
5084  * If we are mounting (or read-write remounting) a filesystem whose journal
5085  * has recorded an error from a previous lifetime, move that error to the
5086  * main filesystem now.
5087  */
5088 static void ext4_clear_journal_err(struct super_block *sb,
5089 				   struct ext4_super_block *es)
5090 {
5091 	journal_t *journal;
5092 	int j_errno;
5093 	const char *errstr;
5094 
5095 	BUG_ON(!ext4_has_feature_journal(sb));
5096 
5097 	journal = EXT4_SB(sb)->s_journal;
5098 
5099 	/*
5100 	 * Now check for any error status which may have been recorded in the
5101 	 * journal by a prior ext4_error() or ext4_abort()
5102 	 */
5103 
5104 	j_errno = jbd2_journal_errno(journal);
5105 	if (j_errno) {
5106 		char nbuf[16];
5107 
5108 		errstr = ext4_decode_error(sb, j_errno, nbuf);
5109 		ext4_warning(sb, "Filesystem error recorded "
5110 			     "from previous mount: %s", errstr);
5111 		ext4_warning(sb, "Marking fs in need of filesystem check.");
5112 
5113 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
5114 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
5115 		ext4_commit_super(sb, 1);
5116 
5117 		jbd2_journal_clear_err(journal);
5118 		jbd2_journal_update_sb_errno(journal);
5119 	}
5120 }
5121 
5122 /*
5123  * Force the running and committing transactions to commit,
5124  * and wait on the commit.
5125  */
5126 int ext4_force_commit(struct super_block *sb)
5127 {
5128 	journal_t *journal;
5129 
5130 	if (sb_rdonly(sb))
5131 		return 0;
5132 
5133 	journal = EXT4_SB(sb)->s_journal;
5134 	return ext4_journal_force_commit(journal);
5135 }
5136 
5137 static int ext4_sync_fs(struct super_block *sb, int wait)
5138 {
5139 	int ret = 0;
5140 	tid_t target;
5141 	bool needs_barrier = false;
5142 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5143 
5144 	if (unlikely(ext4_forced_shutdown(sbi)))
5145 		return 0;
5146 
5147 	trace_ext4_sync_fs(sb, wait);
5148 	flush_workqueue(sbi->rsv_conversion_wq);
5149 	/*
5150 	 * Writeback quota in non-journalled quota case - journalled quota has
5151 	 * no dirty dquots
5152 	 */
5153 	dquot_writeback_dquots(sb, -1);
5154 	/*
5155 	 * Data writeback is possible w/o journal transaction, so barrier must
5156 	 * being sent at the end of the function. But we can skip it if
5157 	 * transaction_commit will do it for us.
5158 	 */
5159 	if (sbi->s_journal) {
5160 		target = jbd2_get_latest_transaction(sbi->s_journal);
5161 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5162 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5163 			needs_barrier = true;
5164 
5165 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5166 			if (wait)
5167 				ret = jbd2_log_wait_commit(sbi->s_journal,
5168 							   target);
5169 		}
5170 	} else if (wait && test_opt(sb, BARRIER))
5171 		needs_barrier = true;
5172 	if (needs_barrier) {
5173 		int err;
5174 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5175 		if (!ret)
5176 			ret = err;
5177 	}
5178 
5179 	return ret;
5180 }
5181 
5182 /*
5183  * LVM calls this function before a (read-only) snapshot is created.  This
5184  * gives us a chance to flush the journal completely and mark the fs clean.
5185  *
5186  * Note that only this function cannot bring a filesystem to be in a clean
5187  * state independently. It relies on upper layer to stop all data & metadata
5188  * modifications.
5189  */
5190 static int ext4_freeze(struct super_block *sb)
5191 {
5192 	int error = 0;
5193 	journal_t *journal;
5194 
5195 	if (sb_rdonly(sb))
5196 		return 0;
5197 
5198 	journal = EXT4_SB(sb)->s_journal;
5199 
5200 	if (journal) {
5201 		/* Now we set up the journal barrier. */
5202 		jbd2_journal_lock_updates(journal);
5203 
5204 		/*
5205 		 * Don't clear the needs_recovery flag if we failed to
5206 		 * flush the journal.
5207 		 */
5208 		error = jbd2_journal_flush(journal);
5209 		if (error < 0)
5210 			goto out;
5211 
5212 		/* Journal blocked and flushed, clear needs_recovery flag. */
5213 		ext4_clear_feature_journal_needs_recovery(sb);
5214 	}
5215 
5216 	error = ext4_commit_super(sb, 1);
5217 out:
5218 	if (journal)
5219 		/* we rely on upper layer to stop further updates */
5220 		jbd2_journal_unlock_updates(journal);
5221 	return error;
5222 }
5223 
5224 /*
5225  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5226  * flag here, even though the filesystem is not technically dirty yet.
5227  */
5228 static int ext4_unfreeze(struct super_block *sb)
5229 {
5230 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5231 		return 0;
5232 
5233 	if (EXT4_SB(sb)->s_journal) {
5234 		/* Reset the needs_recovery flag before the fs is unlocked. */
5235 		ext4_set_feature_journal_needs_recovery(sb);
5236 	}
5237 
5238 	ext4_commit_super(sb, 1);
5239 	return 0;
5240 }
5241 
5242 /*
5243  * Structure to save mount options for ext4_remount's benefit
5244  */
5245 struct ext4_mount_options {
5246 	unsigned long s_mount_opt;
5247 	unsigned long s_mount_opt2;
5248 	kuid_t s_resuid;
5249 	kgid_t s_resgid;
5250 	unsigned long s_commit_interval;
5251 	u32 s_min_batch_time, s_max_batch_time;
5252 #ifdef CONFIG_QUOTA
5253 	int s_jquota_fmt;
5254 	char *s_qf_names[EXT4_MAXQUOTAS];
5255 #endif
5256 };
5257 
5258 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5259 {
5260 	struct ext4_super_block *es;
5261 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5262 	unsigned long old_sb_flags;
5263 	struct ext4_mount_options old_opts;
5264 	int enable_quota = 0;
5265 	ext4_group_t g;
5266 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5267 	int err = 0;
5268 #ifdef CONFIG_QUOTA
5269 	int i, j;
5270 	char *to_free[EXT4_MAXQUOTAS];
5271 #endif
5272 	char *orig_data = kstrdup(data, GFP_KERNEL);
5273 
5274 	if (data && !orig_data)
5275 		return -ENOMEM;
5276 
5277 	/* Store the original options */
5278 	old_sb_flags = sb->s_flags;
5279 	old_opts.s_mount_opt = sbi->s_mount_opt;
5280 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5281 	old_opts.s_resuid = sbi->s_resuid;
5282 	old_opts.s_resgid = sbi->s_resgid;
5283 	old_opts.s_commit_interval = sbi->s_commit_interval;
5284 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5285 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5286 #ifdef CONFIG_QUOTA
5287 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5288 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5289 		if (sbi->s_qf_names[i]) {
5290 			char *qf_name = get_qf_name(sb, sbi, i);
5291 
5292 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5293 			if (!old_opts.s_qf_names[i]) {
5294 				for (j = 0; j < i; j++)
5295 					kfree(old_opts.s_qf_names[j]);
5296 				kfree(orig_data);
5297 				return -ENOMEM;
5298 			}
5299 		} else
5300 			old_opts.s_qf_names[i] = NULL;
5301 #endif
5302 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5303 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5304 
5305 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5306 		err = -EINVAL;
5307 		goto restore_opts;
5308 	}
5309 
5310 	ext4_clamp_want_extra_isize(sb);
5311 
5312 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5313 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5314 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5315 			 "during remount not supported; ignoring");
5316 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5317 	}
5318 
5319 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5320 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5321 			ext4_msg(sb, KERN_ERR, "can't mount with "
5322 				 "both data=journal and delalloc");
5323 			err = -EINVAL;
5324 			goto restore_opts;
5325 		}
5326 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5327 			ext4_msg(sb, KERN_ERR, "can't mount with "
5328 				 "both data=journal and dioread_nolock");
5329 			err = -EINVAL;
5330 			goto restore_opts;
5331 		}
5332 		if (test_opt(sb, DAX)) {
5333 			ext4_msg(sb, KERN_ERR, "can't mount with "
5334 				 "both data=journal and dax");
5335 			err = -EINVAL;
5336 			goto restore_opts;
5337 		}
5338 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5339 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5340 			ext4_msg(sb, KERN_ERR, "can't mount with "
5341 				"journal_async_commit in data=ordered mode");
5342 			err = -EINVAL;
5343 			goto restore_opts;
5344 		}
5345 	}
5346 
5347 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5348 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5349 		err = -EINVAL;
5350 		goto restore_opts;
5351 	}
5352 
5353 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5354 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5355 			"dax flag with busy inodes while remounting");
5356 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5357 	}
5358 
5359 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5360 		ext4_abort(sb, "Abort forced by user");
5361 
5362 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5363 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5364 
5365 	es = sbi->s_es;
5366 
5367 	if (sbi->s_journal) {
5368 		ext4_init_journal_params(sb, sbi->s_journal);
5369 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5370 	}
5371 
5372 	if (*flags & SB_LAZYTIME)
5373 		sb->s_flags |= SB_LAZYTIME;
5374 
5375 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5376 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5377 			err = -EROFS;
5378 			goto restore_opts;
5379 		}
5380 
5381 		if (*flags & SB_RDONLY) {
5382 			err = sync_filesystem(sb);
5383 			if (err < 0)
5384 				goto restore_opts;
5385 			err = dquot_suspend(sb, -1);
5386 			if (err < 0)
5387 				goto restore_opts;
5388 
5389 			/*
5390 			 * First of all, the unconditional stuff we have to do
5391 			 * to disable replay of the journal when we next remount
5392 			 */
5393 			sb->s_flags |= SB_RDONLY;
5394 
5395 			/*
5396 			 * OK, test if we are remounting a valid rw partition
5397 			 * readonly, and if so set the rdonly flag and then
5398 			 * mark the partition as valid again.
5399 			 */
5400 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5401 			    (sbi->s_mount_state & EXT4_VALID_FS))
5402 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5403 
5404 			if (sbi->s_journal)
5405 				ext4_mark_recovery_complete(sb, es);
5406 			if (sbi->s_mmp_tsk)
5407 				kthread_stop(sbi->s_mmp_tsk);
5408 		} else {
5409 			/* Make sure we can mount this feature set readwrite */
5410 			if (ext4_has_feature_readonly(sb) ||
5411 			    !ext4_feature_set_ok(sb, 0)) {
5412 				err = -EROFS;
5413 				goto restore_opts;
5414 			}
5415 			/*
5416 			 * Make sure the group descriptor checksums
5417 			 * are sane.  If they aren't, refuse to remount r/w.
5418 			 */
5419 			for (g = 0; g < sbi->s_groups_count; g++) {
5420 				struct ext4_group_desc *gdp =
5421 					ext4_get_group_desc(sb, g, NULL);
5422 
5423 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5424 					ext4_msg(sb, KERN_ERR,
5425 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5426 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5427 					       le16_to_cpu(gdp->bg_checksum));
5428 					err = -EFSBADCRC;
5429 					goto restore_opts;
5430 				}
5431 			}
5432 
5433 			/*
5434 			 * If we have an unprocessed orphan list hanging
5435 			 * around from a previously readonly bdev mount,
5436 			 * require a full umount/remount for now.
5437 			 */
5438 			if (es->s_last_orphan) {
5439 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5440 				       "remount RDWR because of unprocessed "
5441 				       "orphan inode list.  Please "
5442 				       "umount/remount instead");
5443 				err = -EINVAL;
5444 				goto restore_opts;
5445 			}
5446 
5447 			/*
5448 			 * Mounting a RDONLY partition read-write, so reread
5449 			 * and store the current valid flag.  (It may have
5450 			 * been changed by e2fsck since we originally mounted
5451 			 * the partition.)
5452 			 */
5453 			if (sbi->s_journal)
5454 				ext4_clear_journal_err(sb, es);
5455 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5456 
5457 			err = ext4_setup_super(sb, es, 0);
5458 			if (err)
5459 				goto restore_opts;
5460 
5461 			sb->s_flags &= ~SB_RDONLY;
5462 			if (ext4_has_feature_mmp(sb))
5463 				if (ext4_multi_mount_protect(sb,
5464 						le64_to_cpu(es->s_mmp_block))) {
5465 					err = -EROFS;
5466 					goto restore_opts;
5467 				}
5468 			enable_quota = 1;
5469 		}
5470 	}
5471 
5472 	/*
5473 	 * Reinitialize lazy itable initialization thread based on
5474 	 * current settings
5475 	 */
5476 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5477 		ext4_unregister_li_request(sb);
5478 	else {
5479 		ext4_group_t first_not_zeroed;
5480 		first_not_zeroed = ext4_has_uninit_itable(sb);
5481 		ext4_register_li_request(sb, first_not_zeroed);
5482 	}
5483 
5484 	ext4_setup_system_zone(sb);
5485 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5486 		err = ext4_commit_super(sb, 1);
5487 		if (err)
5488 			goto restore_opts;
5489 	}
5490 
5491 #ifdef CONFIG_QUOTA
5492 	/* Release old quota file names */
5493 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5494 		kfree(old_opts.s_qf_names[i]);
5495 	if (enable_quota) {
5496 		if (sb_any_quota_suspended(sb))
5497 			dquot_resume(sb, -1);
5498 		else if (ext4_has_feature_quota(sb)) {
5499 			err = ext4_enable_quotas(sb);
5500 			if (err)
5501 				goto restore_opts;
5502 		}
5503 	}
5504 #endif
5505 
5506 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5507 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5508 	kfree(orig_data);
5509 	return 0;
5510 
5511 restore_opts:
5512 	sb->s_flags = old_sb_flags;
5513 	sbi->s_mount_opt = old_opts.s_mount_opt;
5514 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5515 	sbi->s_resuid = old_opts.s_resuid;
5516 	sbi->s_resgid = old_opts.s_resgid;
5517 	sbi->s_commit_interval = old_opts.s_commit_interval;
5518 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5519 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5520 #ifdef CONFIG_QUOTA
5521 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5522 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5523 		to_free[i] = get_qf_name(sb, sbi, i);
5524 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5525 	}
5526 	synchronize_rcu();
5527 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5528 		kfree(to_free[i]);
5529 #endif
5530 	kfree(orig_data);
5531 	return err;
5532 }
5533 
5534 #ifdef CONFIG_QUOTA
5535 static int ext4_statfs_project(struct super_block *sb,
5536 			       kprojid_t projid, struct kstatfs *buf)
5537 {
5538 	struct kqid qid;
5539 	struct dquot *dquot;
5540 	u64 limit;
5541 	u64 curblock;
5542 
5543 	qid = make_kqid_projid(projid);
5544 	dquot = dqget(sb, qid);
5545 	if (IS_ERR(dquot))
5546 		return PTR_ERR(dquot);
5547 	spin_lock(&dquot->dq_dqb_lock);
5548 
5549 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5550 		 dquot->dq_dqb.dqb_bsoftlimit :
5551 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5552 	if (limit && buf->f_blocks > limit) {
5553 		curblock = (dquot->dq_dqb.dqb_curspace +
5554 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5555 		buf->f_blocks = limit;
5556 		buf->f_bfree = buf->f_bavail =
5557 			(buf->f_blocks > curblock) ?
5558 			 (buf->f_blocks - curblock) : 0;
5559 	}
5560 
5561 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5562 		dquot->dq_dqb.dqb_isoftlimit :
5563 		dquot->dq_dqb.dqb_ihardlimit;
5564 	if (limit && buf->f_files > limit) {
5565 		buf->f_files = limit;
5566 		buf->f_ffree =
5567 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5568 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5569 	}
5570 
5571 	spin_unlock(&dquot->dq_dqb_lock);
5572 	dqput(dquot);
5573 	return 0;
5574 }
5575 #endif
5576 
5577 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5578 {
5579 	struct super_block *sb = dentry->d_sb;
5580 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5581 	struct ext4_super_block *es = sbi->s_es;
5582 	ext4_fsblk_t overhead = 0, resv_blocks;
5583 	u64 fsid;
5584 	s64 bfree;
5585 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5586 
5587 	if (!test_opt(sb, MINIX_DF))
5588 		overhead = sbi->s_overhead;
5589 
5590 	buf->f_type = EXT4_SUPER_MAGIC;
5591 	buf->f_bsize = sb->s_blocksize;
5592 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5593 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5594 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5595 	/* prevent underflow in case that few free space is available */
5596 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5597 	buf->f_bavail = buf->f_bfree -
5598 			(ext4_r_blocks_count(es) + resv_blocks);
5599 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5600 		buf->f_bavail = 0;
5601 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5602 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5603 	buf->f_namelen = EXT4_NAME_LEN;
5604 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5605 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5606 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5607 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5608 
5609 #ifdef CONFIG_QUOTA
5610 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5611 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5612 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5613 #endif
5614 	return 0;
5615 }
5616 
5617 
5618 #ifdef CONFIG_QUOTA
5619 
5620 /*
5621  * Helper functions so that transaction is started before we acquire dqio_sem
5622  * to keep correct lock ordering of transaction > dqio_sem
5623  */
5624 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5625 {
5626 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5627 }
5628 
5629 static int ext4_write_dquot(struct dquot *dquot)
5630 {
5631 	int ret, err;
5632 	handle_t *handle;
5633 	struct inode *inode;
5634 
5635 	inode = dquot_to_inode(dquot);
5636 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5637 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5638 	if (IS_ERR(handle))
5639 		return PTR_ERR(handle);
5640 	ret = dquot_commit(dquot);
5641 	err = ext4_journal_stop(handle);
5642 	if (!ret)
5643 		ret = err;
5644 	return ret;
5645 }
5646 
5647 static int ext4_acquire_dquot(struct dquot *dquot)
5648 {
5649 	int ret, err;
5650 	handle_t *handle;
5651 
5652 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5653 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5654 	if (IS_ERR(handle))
5655 		return PTR_ERR(handle);
5656 	ret = dquot_acquire(dquot);
5657 	err = ext4_journal_stop(handle);
5658 	if (!ret)
5659 		ret = err;
5660 	return ret;
5661 }
5662 
5663 static int ext4_release_dquot(struct dquot *dquot)
5664 {
5665 	int ret, err;
5666 	handle_t *handle;
5667 
5668 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5669 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5670 	if (IS_ERR(handle)) {
5671 		/* Release dquot anyway to avoid endless cycle in dqput() */
5672 		dquot_release(dquot);
5673 		return PTR_ERR(handle);
5674 	}
5675 	ret = dquot_release(dquot);
5676 	err = ext4_journal_stop(handle);
5677 	if (!ret)
5678 		ret = err;
5679 	return ret;
5680 }
5681 
5682 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5683 {
5684 	struct super_block *sb = dquot->dq_sb;
5685 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5686 
5687 	/* Are we journaling quotas? */
5688 	if (ext4_has_feature_quota(sb) ||
5689 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5690 		dquot_mark_dquot_dirty(dquot);
5691 		return ext4_write_dquot(dquot);
5692 	} else {
5693 		return dquot_mark_dquot_dirty(dquot);
5694 	}
5695 }
5696 
5697 static int ext4_write_info(struct super_block *sb, int type)
5698 {
5699 	int ret, err;
5700 	handle_t *handle;
5701 
5702 	/* Data block + inode block */
5703 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5704 	if (IS_ERR(handle))
5705 		return PTR_ERR(handle);
5706 	ret = dquot_commit_info(sb, type);
5707 	err = ext4_journal_stop(handle);
5708 	if (!ret)
5709 		ret = err;
5710 	return ret;
5711 }
5712 
5713 /*
5714  * Turn on quotas during mount time - we need to find
5715  * the quota file and such...
5716  */
5717 static int ext4_quota_on_mount(struct super_block *sb, int type)
5718 {
5719 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5720 					EXT4_SB(sb)->s_jquota_fmt, type);
5721 }
5722 
5723 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5724 {
5725 	struct ext4_inode_info *ei = EXT4_I(inode);
5726 
5727 	/* The first argument of lockdep_set_subclass has to be
5728 	 * *exactly* the same as the argument to init_rwsem() --- in
5729 	 * this case, in init_once() --- or lockdep gets unhappy
5730 	 * because the name of the lock is set using the
5731 	 * stringification of the argument to init_rwsem().
5732 	 */
5733 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5734 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5735 }
5736 
5737 /*
5738  * Standard function to be called on quota_on
5739  */
5740 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5741 			 const struct path *path)
5742 {
5743 	int err;
5744 
5745 	if (!test_opt(sb, QUOTA))
5746 		return -EINVAL;
5747 
5748 	/* Quotafile not on the same filesystem? */
5749 	if (path->dentry->d_sb != sb)
5750 		return -EXDEV;
5751 	/* Journaling quota? */
5752 	if (EXT4_SB(sb)->s_qf_names[type]) {
5753 		/* Quotafile not in fs root? */
5754 		if (path->dentry->d_parent != sb->s_root)
5755 			ext4_msg(sb, KERN_WARNING,
5756 				"Quota file not on filesystem root. "
5757 				"Journaled quota will not work");
5758 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5759 	} else {
5760 		/*
5761 		 * Clear the flag just in case mount options changed since
5762 		 * last time.
5763 		 */
5764 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5765 	}
5766 
5767 	/*
5768 	 * When we journal data on quota file, we have to flush journal to see
5769 	 * all updates to the file when we bypass pagecache...
5770 	 */
5771 	if (EXT4_SB(sb)->s_journal &&
5772 	    ext4_should_journal_data(d_inode(path->dentry))) {
5773 		/*
5774 		 * We don't need to lock updates but journal_flush() could
5775 		 * otherwise be livelocked...
5776 		 */
5777 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5778 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5779 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5780 		if (err)
5781 			return err;
5782 	}
5783 
5784 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5785 	err = dquot_quota_on(sb, type, format_id, path);
5786 	if (err) {
5787 		lockdep_set_quota_inode(path->dentry->d_inode,
5788 					     I_DATA_SEM_NORMAL);
5789 	} else {
5790 		struct inode *inode = d_inode(path->dentry);
5791 		handle_t *handle;
5792 
5793 		/*
5794 		 * Set inode flags to prevent userspace from messing with quota
5795 		 * files. If this fails, we return success anyway since quotas
5796 		 * are already enabled and this is not a hard failure.
5797 		 */
5798 		inode_lock(inode);
5799 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5800 		if (IS_ERR(handle))
5801 			goto unlock_inode;
5802 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5803 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5804 				S_NOATIME | S_IMMUTABLE);
5805 		ext4_mark_inode_dirty(handle, inode);
5806 		ext4_journal_stop(handle);
5807 	unlock_inode:
5808 		inode_unlock(inode);
5809 	}
5810 	return err;
5811 }
5812 
5813 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5814 			     unsigned int flags)
5815 {
5816 	int err;
5817 	struct inode *qf_inode;
5818 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5819 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5820 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5821 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5822 	};
5823 
5824 	BUG_ON(!ext4_has_feature_quota(sb));
5825 
5826 	if (!qf_inums[type])
5827 		return -EPERM;
5828 
5829 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5830 	if (IS_ERR(qf_inode)) {
5831 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5832 		return PTR_ERR(qf_inode);
5833 	}
5834 
5835 	/* Don't account quota for quota files to avoid recursion */
5836 	qf_inode->i_flags |= S_NOQUOTA;
5837 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5838 	err = dquot_enable(qf_inode, type, format_id, flags);
5839 	if (err)
5840 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5841 	iput(qf_inode);
5842 
5843 	return err;
5844 }
5845 
5846 /* Enable usage tracking for all quota types. */
5847 static int ext4_enable_quotas(struct super_block *sb)
5848 {
5849 	int type, err = 0;
5850 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5851 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5852 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5853 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5854 	};
5855 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5856 		test_opt(sb, USRQUOTA),
5857 		test_opt(sb, GRPQUOTA),
5858 		test_opt(sb, PRJQUOTA),
5859 	};
5860 
5861 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5862 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5863 		if (qf_inums[type]) {
5864 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5865 				DQUOT_USAGE_ENABLED |
5866 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5867 			if (err) {
5868 				ext4_warning(sb,
5869 					"Failed to enable quota tracking "
5870 					"(type=%d, err=%d). Please run "
5871 					"e2fsck to fix.", type, err);
5872 				for (type--; type >= 0; type--)
5873 					dquot_quota_off(sb, type);
5874 
5875 				return err;
5876 			}
5877 		}
5878 	}
5879 	return 0;
5880 }
5881 
5882 static int ext4_quota_off(struct super_block *sb, int type)
5883 {
5884 	struct inode *inode = sb_dqopt(sb)->files[type];
5885 	handle_t *handle;
5886 	int err;
5887 
5888 	/* Force all delayed allocation blocks to be allocated.
5889 	 * Caller already holds s_umount sem */
5890 	if (test_opt(sb, DELALLOC))
5891 		sync_filesystem(sb);
5892 
5893 	if (!inode || !igrab(inode))
5894 		goto out;
5895 
5896 	err = dquot_quota_off(sb, type);
5897 	if (err || ext4_has_feature_quota(sb))
5898 		goto out_put;
5899 
5900 	inode_lock(inode);
5901 	/*
5902 	 * Update modification times of quota files when userspace can
5903 	 * start looking at them. If we fail, we return success anyway since
5904 	 * this is not a hard failure and quotas are already disabled.
5905 	 */
5906 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5907 	if (IS_ERR(handle))
5908 		goto out_unlock;
5909 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5910 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5911 	inode->i_mtime = inode->i_ctime = current_time(inode);
5912 	ext4_mark_inode_dirty(handle, inode);
5913 	ext4_journal_stop(handle);
5914 out_unlock:
5915 	inode_unlock(inode);
5916 out_put:
5917 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5918 	iput(inode);
5919 	return err;
5920 out:
5921 	return dquot_quota_off(sb, type);
5922 }
5923 
5924 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5925  * acquiring the locks... As quota files are never truncated and quota code
5926  * itself serializes the operations (and no one else should touch the files)
5927  * we don't have to be afraid of races */
5928 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5929 			       size_t len, loff_t off)
5930 {
5931 	struct inode *inode = sb_dqopt(sb)->files[type];
5932 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5933 	int offset = off & (sb->s_blocksize - 1);
5934 	int tocopy;
5935 	size_t toread;
5936 	struct buffer_head *bh;
5937 	loff_t i_size = i_size_read(inode);
5938 
5939 	if (off > i_size)
5940 		return 0;
5941 	if (off+len > i_size)
5942 		len = i_size-off;
5943 	toread = len;
5944 	while (toread > 0) {
5945 		tocopy = sb->s_blocksize - offset < toread ?
5946 				sb->s_blocksize - offset : toread;
5947 		bh = ext4_bread(NULL, inode, blk, 0);
5948 		if (IS_ERR(bh))
5949 			return PTR_ERR(bh);
5950 		if (!bh)	/* A hole? */
5951 			memset(data, 0, tocopy);
5952 		else
5953 			memcpy(data, bh->b_data+offset, tocopy);
5954 		brelse(bh);
5955 		offset = 0;
5956 		toread -= tocopy;
5957 		data += tocopy;
5958 		blk++;
5959 	}
5960 	return len;
5961 }
5962 
5963 /* Write to quotafile (we know the transaction is already started and has
5964  * enough credits) */
5965 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5966 				const char *data, size_t len, loff_t off)
5967 {
5968 	struct inode *inode = sb_dqopt(sb)->files[type];
5969 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5970 	int err, offset = off & (sb->s_blocksize - 1);
5971 	int retries = 0;
5972 	struct buffer_head *bh;
5973 	handle_t *handle = journal_current_handle();
5974 
5975 	if (EXT4_SB(sb)->s_journal && !handle) {
5976 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5977 			" cancelled because transaction is not started",
5978 			(unsigned long long)off, (unsigned long long)len);
5979 		return -EIO;
5980 	}
5981 	/*
5982 	 * Since we account only one data block in transaction credits,
5983 	 * then it is impossible to cross a block boundary.
5984 	 */
5985 	if (sb->s_blocksize - offset < len) {
5986 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5987 			" cancelled because not block aligned",
5988 			(unsigned long long)off, (unsigned long long)len);
5989 		return -EIO;
5990 	}
5991 
5992 	do {
5993 		bh = ext4_bread(handle, inode, blk,
5994 				EXT4_GET_BLOCKS_CREATE |
5995 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5996 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5997 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5998 	if (IS_ERR(bh))
5999 		return PTR_ERR(bh);
6000 	if (!bh)
6001 		goto out;
6002 	BUFFER_TRACE(bh, "get write access");
6003 	err = ext4_journal_get_write_access(handle, bh);
6004 	if (err) {
6005 		brelse(bh);
6006 		return err;
6007 	}
6008 	lock_buffer(bh);
6009 	memcpy(bh->b_data+offset, data, len);
6010 	flush_dcache_page(bh->b_page);
6011 	unlock_buffer(bh);
6012 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
6013 	brelse(bh);
6014 out:
6015 	if (inode->i_size < off + len) {
6016 		i_size_write(inode, off + len);
6017 		EXT4_I(inode)->i_disksize = inode->i_size;
6018 		ext4_mark_inode_dirty(handle, inode);
6019 	}
6020 	return len;
6021 }
6022 
6023 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
6024 {
6025 	const struct quota_format_ops	*ops;
6026 
6027 	if (!sb_has_quota_loaded(sb, qid->type))
6028 		return -ESRCH;
6029 	ops = sb_dqopt(sb)->ops[qid->type];
6030 	if (!ops || !ops->get_next_id)
6031 		return -ENOSYS;
6032 	return dquot_get_next_id(sb, qid);
6033 }
6034 #endif
6035 
6036 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
6037 		       const char *dev_name, void *data)
6038 {
6039 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
6040 }
6041 
6042 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
6043 static inline void register_as_ext2(void)
6044 {
6045 	int err = register_filesystem(&ext2_fs_type);
6046 	if (err)
6047 		printk(KERN_WARNING
6048 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
6049 }
6050 
6051 static inline void unregister_as_ext2(void)
6052 {
6053 	unregister_filesystem(&ext2_fs_type);
6054 }
6055 
6056 static inline int ext2_feature_set_ok(struct super_block *sb)
6057 {
6058 	if (ext4_has_unknown_ext2_incompat_features(sb))
6059 		return 0;
6060 	if (sb_rdonly(sb))
6061 		return 1;
6062 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
6063 		return 0;
6064 	return 1;
6065 }
6066 #else
6067 static inline void register_as_ext2(void) { }
6068 static inline void unregister_as_ext2(void) { }
6069 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
6070 #endif
6071 
6072 static inline void register_as_ext3(void)
6073 {
6074 	int err = register_filesystem(&ext3_fs_type);
6075 	if (err)
6076 		printk(KERN_WARNING
6077 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
6078 }
6079 
6080 static inline void unregister_as_ext3(void)
6081 {
6082 	unregister_filesystem(&ext3_fs_type);
6083 }
6084 
6085 static inline int ext3_feature_set_ok(struct super_block *sb)
6086 {
6087 	if (ext4_has_unknown_ext3_incompat_features(sb))
6088 		return 0;
6089 	if (!ext4_has_feature_journal(sb))
6090 		return 0;
6091 	if (sb_rdonly(sb))
6092 		return 1;
6093 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
6094 		return 0;
6095 	return 1;
6096 }
6097 
6098 static struct file_system_type ext4_fs_type = {
6099 	.owner		= THIS_MODULE,
6100 	.name		= "ext4",
6101 	.mount		= ext4_mount,
6102 	.kill_sb	= kill_block_super,
6103 	.fs_flags	= FS_REQUIRES_DEV,
6104 };
6105 MODULE_ALIAS_FS("ext4");
6106 
6107 /* Shared across all ext4 file systems */
6108 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
6109 
6110 static int __init ext4_init_fs(void)
6111 {
6112 	int i, err;
6113 
6114 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
6115 	ext4_li_info = NULL;
6116 	mutex_init(&ext4_li_mtx);
6117 
6118 	/* Build-time check for flags consistency */
6119 	ext4_check_flag_values();
6120 
6121 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
6122 		init_waitqueue_head(&ext4__ioend_wq[i]);
6123 
6124 	err = ext4_init_es();
6125 	if (err)
6126 		return err;
6127 
6128 	err = ext4_init_pending();
6129 	if (err)
6130 		goto out7;
6131 
6132 	err = ext4_init_post_read_processing();
6133 	if (err)
6134 		goto out6;
6135 
6136 	err = ext4_init_pageio();
6137 	if (err)
6138 		goto out5;
6139 
6140 	err = ext4_init_system_zone();
6141 	if (err)
6142 		goto out4;
6143 
6144 	err = ext4_init_sysfs();
6145 	if (err)
6146 		goto out3;
6147 
6148 	err = ext4_init_mballoc();
6149 	if (err)
6150 		goto out2;
6151 	err = init_inodecache();
6152 	if (err)
6153 		goto out1;
6154 	register_as_ext3();
6155 	register_as_ext2();
6156 	err = register_filesystem(&ext4_fs_type);
6157 	if (err)
6158 		goto out;
6159 
6160 	return 0;
6161 out:
6162 	unregister_as_ext2();
6163 	unregister_as_ext3();
6164 	destroy_inodecache();
6165 out1:
6166 	ext4_exit_mballoc();
6167 out2:
6168 	ext4_exit_sysfs();
6169 out3:
6170 	ext4_exit_system_zone();
6171 out4:
6172 	ext4_exit_pageio();
6173 out5:
6174 	ext4_exit_post_read_processing();
6175 out6:
6176 	ext4_exit_pending();
6177 out7:
6178 	ext4_exit_es();
6179 
6180 	return err;
6181 }
6182 
6183 static void __exit ext4_exit_fs(void)
6184 {
6185 	ext4_destroy_lazyinit_thread();
6186 	unregister_as_ext2();
6187 	unregister_as_ext3();
6188 	unregister_filesystem(&ext4_fs_type);
6189 	destroy_inodecache();
6190 	ext4_exit_mballoc();
6191 	ext4_exit_sysfs();
6192 	ext4_exit_system_zone();
6193 	ext4_exit_pageio();
6194 	ext4_exit_post_read_processing();
6195 	ext4_exit_es();
6196 	ext4_exit_pending();
6197 }
6198 
6199 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6200 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6201 MODULE_LICENSE("GPL");
6202 MODULE_SOFTDEP("pre: crc32c");
6203 module_init(ext4_init_fs)
6204 module_exit(ext4_exit_fs)
6205