xref: /openbmc/linux/fs/ext4/super.c (revision c71bb9f8)
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 
46 #include <linux/kthread.h>
47 #include <linux/freezer.h>
48 
49 #include "ext4.h"
50 #include "ext4_extents.h"	/* Needed for trace points definition */
51 #include "ext4_jbd2.h"
52 #include "xattr.h"
53 #include "acl.h"
54 #include "mballoc.h"
55 #include "fsmap.h"
56 
57 #define CREATE_TRACE_POINTS
58 #include <trace/events/ext4.h>
59 
60 static struct ext4_lazy_init *ext4_li_info;
61 static struct mutex ext4_li_mtx;
62 static struct ratelimit_state ext4_mount_msg_ratelimit;
63 
64 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
65 			     unsigned long journal_devnum);
66 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
67 static int ext4_commit_super(struct super_block *sb, int sync);
68 static void ext4_mark_recovery_complete(struct super_block *sb,
69 					struct ext4_super_block *es);
70 static void ext4_clear_journal_err(struct super_block *sb,
71 				   struct ext4_super_block *es);
72 static int ext4_sync_fs(struct super_block *sb, int wait);
73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
75 static int ext4_unfreeze(struct super_block *sb);
76 static int ext4_freeze(struct super_block *sb);
77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
78 		       const char *dev_name, void *data);
79 static inline int ext2_feature_set_ok(struct super_block *sb);
80 static inline int ext3_feature_set_ok(struct super_block *sb);
81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static struct inode *ext4_get_journal_inode(struct super_block *sb,
86 					    unsigned int journal_inum);
87 
88 /*
89  * Lock ordering
90  *
91  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
92  * i_mmap_rwsem (inode->i_mmap_rwsem)!
93  *
94  * page fault path:
95  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
96  *   page lock -> i_data_sem (rw)
97  *
98  * buffered write path:
99  * sb_start_write -> i_mutex -> mmap_sem
100  * sb_start_write -> i_mutex -> transaction start -> page lock ->
101  *   i_data_sem (rw)
102  *
103  * truncate:
104  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> i_mmap_rwsem (w) -> page lock
105  * sb_start_write -> i_mutex -> i_mmap_sem (w) -> transaction start ->
106  *   i_data_sem (rw)
107  *
108  * direct IO:
109  * sb_start_write -> i_mutex -> mmap_sem
110  * sb_start_write -> i_mutex -> transaction start -> i_data_sem (rw)
111  *
112  * writepages:
113  * transaction start -> page lock(s) -> i_data_sem (rw)
114  */
115 
116 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
117 static struct file_system_type ext2_fs_type = {
118 	.owner		= THIS_MODULE,
119 	.name		= "ext2",
120 	.mount		= ext4_mount,
121 	.kill_sb	= kill_block_super,
122 	.fs_flags	= FS_REQUIRES_DEV,
123 };
124 MODULE_ALIAS_FS("ext2");
125 MODULE_ALIAS("ext2");
126 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
127 #else
128 #define IS_EXT2_SB(sb) (0)
129 #endif
130 
131 
132 static struct file_system_type ext3_fs_type = {
133 	.owner		= THIS_MODULE,
134 	.name		= "ext3",
135 	.mount		= ext4_mount,
136 	.kill_sb	= kill_block_super,
137 	.fs_flags	= FS_REQUIRES_DEV,
138 };
139 MODULE_ALIAS_FS("ext3");
140 MODULE_ALIAS("ext3");
141 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
142 
143 /*
144  * This works like sb_bread() except it uses ERR_PTR for error
145  * returns.  Currently with sb_bread it's impossible to distinguish
146  * between ENOMEM and EIO situations (since both result in a NULL
147  * return.
148  */
149 struct buffer_head *
150 ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
151 {
152 	struct buffer_head *bh = sb_getblk(sb, block);
153 
154 	if (bh == NULL)
155 		return ERR_PTR(-ENOMEM);
156 	if (buffer_uptodate(bh))
157 		return bh;
158 	ll_rw_block(REQ_OP_READ, REQ_META | op_flags, 1, &bh);
159 	wait_on_buffer(bh);
160 	if (buffer_uptodate(bh))
161 		return bh;
162 	put_bh(bh);
163 	return ERR_PTR(-EIO);
164 }
165 
166 static int ext4_verify_csum_type(struct super_block *sb,
167 				 struct ext4_super_block *es)
168 {
169 	if (!ext4_has_feature_metadata_csum(sb))
170 		return 1;
171 
172 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
173 }
174 
175 static __le32 ext4_superblock_csum(struct super_block *sb,
176 				   struct ext4_super_block *es)
177 {
178 	struct ext4_sb_info *sbi = EXT4_SB(sb);
179 	int offset = offsetof(struct ext4_super_block, s_checksum);
180 	__u32 csum;
181 
182 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
183 
184 	return cpu_to_le32(csum);
185 }
186 
187 static int ext4_superblock_csum_verify(struct super_block *sb,
188 				       struct ext4_super_block *es)
189 {
190 	if (!ext4_has_metadata_csum(sb))
191 		return 1;
192 
193 	return es->s_checksum == ext4_superblock_csum(sb, es);
194 }
195 
196 void ext4_superblock_csum_set(struct super_block *sb)
197 {
198 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
199 
200 	if (!ext4_has_metadata_csum(sb))
201 		return;
202 
203 	es->s_checksum = ext4_superblock_csum(sb, es);
204 }
205 
206 void *ext4_kvmalloc(size_t size, gfp_t flags)
207 {
208 	void *ret;
209 
210 	ret = kmalloc(size, flags | __GFP_NOWARN);
211 	if (!ret)
212 		ret = __vmalloc(size, flags, PAGE_KERNEL);
213 	return ret;
214 }
215 
216 void *ext4_kvzalloc(size_t size, gfp_t flags)
217 {
218 	void *ret;
219 
220 	ret = kzalloc(size, flags | __GFP_NOWARN);
221 	if (!ret)
222 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
223 	return ret;
224 }
225 
226 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
227 			       struct ext4_group_desc *bg)
228 {
229 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
230 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
231 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
232 }
233 
234 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
235 			       struct ext4_group_desc *bg)
236 {
237 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
238 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
239 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
240 }
241 
242 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
243 			      struct ext4_group_desc *bg)
244 {
245 	return le32_to_cpu(bg->bg_inode_table_lo) |
246 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
247 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
248 }
249 
250 __u32 ext4_free_group_clusters(struct super_block *sb,
251 			       struct ext4_group_desc *bg)
252 {
253 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
254 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
255 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
256 }
257 
258 __u32 ext4_free_inodes_count(struct super_block *sb,
259 			      struct ext4_group_desc *bg)
260 {
261 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
262 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
263 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
264 }
265 
266 __u32 ext4_used_dirs_count(struct super_block *sb,
267 			      struct ext4_group_desc *bg)
268 {
269 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
270 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
271 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
272 }
273 
274 __u32 ext4_itable_unused_count(struct super_block *sb,
275 			      struct ext4_group_desc *bg)
276 {
277 	return le16_to_cpu(bg->bg_itable_unused_lo) |
278 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
279 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
280 }
281 
282 void ext4_block_bitmap_set(struct super_block *sb,
283 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
284 {
285 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
286 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
287 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
288 }
289 
290 void ext4_inode_bitmap_set(struct super_block *sb,
291 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
292 {
293 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
294 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
295 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
296 }
297 
298 void ext4_inode_table_set(struct super_block *sb,
299 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
300 {
301 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
302 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
303 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
304 }
305 
306 void ext4_free_group_clusters_set(struct super_block *sb,
307 				  struct ext4_group_desc *bg, __u32 count)
308 {
309 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
310 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
311 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
312 }
313 
314 void ext4_free_inodes_set(struct super_block *sb,
315 			  struct ext4_group_desc *bg, __u32 count)
316 {
317 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
318 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
319 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
320 }
321 
322 void ext4_used_dirs_set(struct super_block *sb,
323 			  struct ext4_group_desc *bg, __u32 count)
324 {
325 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
326 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
327 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
328 }
329 
330 void ext4_itable_unused_set(struct super_block *sb,
331 			  struct ext4_group_desc *bg, __u32 count)
332 {
333 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
334 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
335 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
336 }
337 
338 static void __ext4_update_tstamp(__le32 *lo, __u8 *hi)
339 {
340 	time64_t now = ktime_get_real_seconds();
341 
342 	now = clamp_val(now, 0, (1ull << 40) - 1);
343 
344 	*lo = cpu_to_le32(lower_32_bits(now));
345 	*hi = upper_32_bits(now);
346 }
347 
348 static time64_t __ext4_get_tstamp(__le32 *lo, __u8 *hi)
349 {
350 	return ((time64_t)(*hi) << 32) + le32_to_cpu(*lo);
351 }
352 #define ext4_update_tstamp(es, tstamp) \
353 	__ext4_update_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
354 #define ext4_get_tstamp(es, tstamp) \
355 	__ext4_get_tstamp(&(es)->tstamp, &(es)->tstamp ## _hi)
356 
357 static void __save_error_info(struct super_block *sb, const char *func,
358 			    unsigned int line)
359 {
360 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
361 
362 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
363 	if (bdev_read_only(sb->s_bdev))
364 		return;
365 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
366 	ext4_update_tstamp(es, s_last_error_time);
367 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
368 	es->s_last_error_line = cpu_to_le32(line);
369 	if (!es->s_first_error_time) {
370 		es->s_first_error_time = es->s_last_error_time;
371 		es->s_first_error_time_hi = es->s_last_error_time_hi;
372 		strncpy(es->s_first_error_func, func,
373 			sizeof(es->s_first_error_func));
374 		es->s_first_error_line = cpu_to_le32(line);
375 		es->s_first_error_ino = es->s_last_error_ino;
376 		es->s_first_error_block = es->s_last_error_block;
377 	}
378 	/*
379 	 * Start the daily error reporting function if it hasn't been
380 	 * started already
381 	 */
382 	if (!es->s_error_count)
383 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
384 	le32_add_cpu(&es->s_error_count, 1);
385 }
386 
387 static void save_error_info(struct super_block *sb, const char *func,
388 			    unsigned int line)
389 {
390 	__save_error_info(sb, func, line);
391 	ext4_commit_super(sb, 1);
392 }
393 
394 /*
395  * The del_gendisk() function uninitializes the disk-specific data
396  * structures, including the bdi structure, without telling anyone
397  * else.  Once this happens, any attempt to call mark_buffer_dirty()
398  * (for example, by ext4_commit_super), will cause a kernel OOPS.
399  * This is a kludge to prevent these oops until we can put in a proper
400  * hook in del_gendisk() to inform the VFS and file system layers.
401  */
402 static int block_device_ejected(struct super_block *sb)
403 {
404 	struct inode *bd_inode = sb->s_bdev->bd_inode;
405 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
406 
407 	return bdi->dev == NULL;
408 }
409 
410 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
411 {
412 	struct super_block		*sb = journal->j_private;
413 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
414 	int				error = is_journal_aborted(journal);
415 	struct ext4_journal_cb_entry	*jce;
416 
417 	BUG_ON(txn->t_state == T_FINISHED);
418 
419 	ext4_process_freed_data(sb, txn->t_tid);
420 
421 	spin_lock(&sbi->s_md_lock);
422 	while (!list_empty(&txn->t_private_list)) {
423 		jce = list_entry(txn->t_private_list.next,
424 				 struct ext4_journal_cb_entry, jce_list);
425 		list_del_init(&jce->jce_list);
426 		spin_unlock(&sbi->s_md_lock);
427 		jce->jce_func(sb, jce, error);
428 		spin_lock(&sbi->s_md_lock);
429 	}
430 	spin_unlock(&sbi->s_md_lock);
431 }
432 
433 /* Deal with the reporting of failure conditions on a filesystem such as
434  * inconsistencies detected or read IO failures.
435  *
436  * On ext2, we can store the error state of the filesystem in the
437  * superblock.  That is not possible on ext4, because we may have other
438  * write ordering constraints on the superblock which prevent us from
439  * writing it out straight away; and given that the journal is about to
440  * be aborted, we can't rely on the current, or future, transactions to
441  * write out the superblock safely.
442  *
443  * We'll just use the jbd2_journal_abort() error code to record an error in
444  * the journal instead.  On recovery, the journal will complain about
445  * that error until we've noted it down and cleared it.
446  */
447 
448 static void ext4_handle_error(struct super_block *sb)
449 {
450 	if (test_opt(sb, WARN_ON_ERROR))
451 		WARN_ON_ONCE(1);
452 
453 	if (sb_rdonly(sb))
454 		return;
455 
456 	if (!test_opt(sb, ERRORS_CONT)) {
457 		journal_t *journal = EXT4_SB(sb)->s_journal;
458 
459 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
460 		if (journal)
461 			jbd2_journal_abort(journal, -EIO);
462 	}
463 	if (test_opt(sb, ERRORS_RO)) {
464 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
465 		/*
466 		 * Make sure updated value of ->s_mount_flags will be visible
467 		 * before ->s_flags update
468 		 */
469 		smp_wmb();
470 		sb->s_flags |= SB_RDONLY;
471 	}
472 	if (test_opt(sb, ERRORS_PANIC)) {
473 		if (EXT4_SB(sb)->s_journal &&
474 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
475 			return;
476 		panic("EXT4-fs (device %s): panic forced after error\n",
477 			sb->s_id);
478 	}
479 }
480 
481 #define ext4_error_ratelimit(sb)					\
482 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
483 			     "EXT4-fs error")
484 
485 void __ext4_error(struct super_block *sb, const char *function,
486 		  unsigned int line, const char *fmt, ...)
487 {
488 	struct va_format vaf;
489 	va_list args;
490 
491 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
492 		return;
493 
494 	trace_ext4_error(sb, function, line);
495 	if (ext4_error_ratelimit(sb)) {
496 		va_start(args, fmt);
497 		vaf.fmt = fmt;
498 		vaf.va = &args;
499 		printk(KERN_CRIT
500 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
501 		       sb->s_id, function, line, current->comm, &vaf);
502 		va_end(args);
503 	}
504 	save_error_info(sb, function, line);
505 	ext4_handle_error(sb);
506 }
507 
508 void __ext4_error_inode(struct inode *inode, const char *function,
509 			unsigned int line, ext4_fsblk_t block,
510 			const char *fmt, ...)
511 {
512 	va_list args;
513 	struct va_format vaf;
514 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
515 
516 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
517 		return;
518 
519 	trace_ext4_error(inode->i_sb, function, line);
520 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
521 	es->s_last_error_block = cpu_to_le64(block);
522 	if (ext4_error_ratelimit(inode->i_sb)) {
523 		va_start(args, fmt);
524 		vaf.fmt = fmt;
525 		vaf.va = &args;
526 		if (block)
527 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
528 			       "inode #%lu: block %llu: comm %s: %pV\n",
529 			       inode->i_sb->s_id, function, line, inode->i_ino,
530 			       block, current->comm, &vaf);
531 		else
532 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
533 			       "inode #%lu: comm %s: %pV\n",
534 			       inode->i_sb->s_id, function, line, inode->i_ino,
535 			       current->comm, &vaf);
536 		va_end(args);
537 	}
538 	save_error_info(inode->i_sb, function, line);
539 	ext4_handle_error(inode->i_sb);
540 }
541 
542 void __ext4_error_file(struct file *file, const char *function,
543 		       unsigned int line, ext4_fsblk_t block,
544 		       const char *fmt, ...)
545 {
546 	va_list args;
547 	struct va_format vaf;
548 	struct ext4_super_block *es;
549 	struct inode *inode = file_inode(file);
550 	char pathname[80], *path;
551 
552 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
553 		return;
554 
555 	trace_ext4_error(inode->i_sb, function, line);
556 	es = EXT4_SB(inode->i_sb)->s_es;
557 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
558 	if (ext4_error_ratelimit(inode->i_sb)) {
559 		path = file_path(file, pathname, sizeof(pathname));
560 		if (IS_ERR(path))
561 			path = "(unknown)";
562 		va_start(args, fmt);
563 		vaf.fmt = fmt;
564 		vaf.va = &args;
565 		if (block)
566 			printk(KERN_CRIT
567 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
568 			       "block %llu: comm %s: path %s: %pV\n",
569 			       inode->i_sb->s_id, function, line, inode->i_ino,
570 			       block, current->comm, path, &vaf);
571 		else
572 			printk(KERN_CRIT
573 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
574 			       "comm %s: path %s: %pV\n",
575 			       inode->i_sb->s_id, function, line, inode->i_ino,
576 			       current->comm, path, &vaf);
577 		va_end(args);
578 	}
579 	save_error_info(inode->i_sb, function, line);
580 	ext4_handle_error(inode->i_sb);
581 }
582 
583 const char *ext4_decode_error(struct super_block *sb, int errno,
584 			      char nbuf[16])
585 {
586 	char *errstr = NULL;
587 
588 	switch (errno) {
589 	case -EFSCORRUPTED:
590 		errstr = "Corrupt filesystem";
591 		break;
592 	case -EFSBADCRC:
593 		errstr = "Filesystem failed CRC";
594 		break;
595 	case -EIO:
596 		errstr = "IO failure";
597 		break;
598 	case -ENOMEM:
599 		errstr = "Out of memory";
600 		break;
601 	case -EROFS:
602 		if (!sb || (EXT4_SB(sb)->s_journal &&
603 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
604 			errstr = "Journal has aborted";
605 		else
606 			errstr = "Readonly filesystem";
607 		break;
608 	default:
609 		/* If the caller passed in an extra buffer for unknown
610 		 * errors, textualise them now.  Else we just return
611 		 * NULL. */
612 		if (nbuf) {
613 			/* Check for truncated error codes... */
614 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
615 				errstr = nbuf;
616 		}
617 		break;
618 	}
619 
620 	return errstr;
621 }
622 
623 /* __ext4_std_error decodes expected errors from journaling functions
624  * automatically and invokes the appropriate error response.  */
625 
626 void __ext4_std_error(struct super_block *sb, const char *function,
627 		      unsigned int line, int errno)
628 {
629 	char nbuf[16];
630 	const char *errstr;
631 
632 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
633 		return;
634 
635 	/* Special case: if the error is EROFS, and we're not already
636 	 * inside a transaction, then there's really no point in logging
637 	 * an error. */
638 	if (errno == -EROFS && journal_current_handle() == NULL && sb_rdonly(sb))
639 		return;
640 
641 	if (ext4_error_ratelimit(sb)) {
642 		errstr = ext4_decode_error(sb, errno, nbuf);
643 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
644 		       sb->s_id, function, line, errstr);
645 	}
646 
647 	save_error_info(sb, function, line);
648 	ext4_handle_error(sb);
649 }
650 
651 /*
652  * ext4_abort is a much stronger failure handler than ext4_error.  The
653  * abort function may be used to deal with unrecoverable failures such
654  * as journal IO errors or ENOMEM at a critical moment in log management.
655  *
656  * We unconditionally force the filesystem into an ABORT|READONLY state,
657  * unless the error response on the fs has been set to panic in which
658  * case we take the easy way out and panic immediately.
659  */
660 
661 void __ext4_abort(struct super_block *sb, const char *function,
662 		unsigned int line, const char *fmt, ...)
663 {
664 	struct va_format vaf;
665 	va_list args;
666 
667 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
668 		return;
669 
670 	save_error_info(sb, function, line);
671 	va_start(args, fmt);
672 	vaf.fmt = fmt;
673 	vaf.va = &args;
674 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
675 	       sb->s_id, function, line, &vaf);
676 	va_end(args);
677 
678 	if (sb_rdonly(sb) == 0) {
679 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
680 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
681 		/*
682 		 * Make sure updated value of ->s_mount_flags will be visible
683 		 * before ->s_flags update
684 		 */
685 		smp_wmb();
686 		sb->s_flags |= SB_RDONLY;
687 		if (EXT4_SB(sb)->s_journal)
688 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
689 		save_error_info(sb, function, line);
690 	}
691 	if (test_opt(sb, ERRORS_PANIC)) {
692 		if (EXT4_SB(sb)->s_journal &&
693 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
694 			return;
695 		panic("EXT4-fs panic from previous error\n");
696 	}
697 }
698 
699 void __ext4_msg(struct super_block *sb,
700 		const char *prefix, const char *fmt, ...)
701 {
702 	struct va_format vaf;
703 	va_list args;
704 
705 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
706 		return;
707 
708 	va_start(args, fmt);
709 	vaf.fmt = fmt;
710 	vaf.va = &args;
711 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
712 	va_end(args);
713 }
714 
715 #define ext4_warning_ratelimit(sb)					\
716 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
717 			     "EXT4-fs warning")
718 
719 void __ext4_warning(struct super_block *sb, const char *function,
720 		    unsigned int line, const char *fmt, ...)
721 {
722 	struct va_format vaf;
723 	va_list args;
724 
725 	if (!ext4_warning_ratelimit(sb))
726 		return;
727 
728 	va_start(args, fmt);
729 	vaf.fmt = fmt;
730 	vaf.va = &args;
731 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
732 	       sb->s_id, function, line, &vaf);
733 	va_end(args);
734 }
735 
736 void __ext4_warning_inode(const struct inode *inode, const char *function,
737 			  unsigned int line, const char *fmt, ...)
738 {
739 	struct va_format vaf;
740 	va_list args;
741 
742 	if (!ext4_warning_ratelimit(inode->i_sb))
743 		return;
744 
745 	va_start(args, fmt);
746 	vaf.fmt = fmt;
747 	vaf.va = &args;
748 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
749 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
750 	       function, line, inode->i_ino, current->comm, &vaf);
751 	va_end(args);
752 }
753 
754 void __ext4_grp_locked_error(const char *function, unsigned int line,
755 			     struct super_block *sb, ext4_group_t grp,
756 			     unsigned long ino, ext4_fsblk_t block,
757 			     const char *fmt, ...)
758 __releases(bitlock)
759 __acquires(bitlock)
760 {
761 	struct va_format vaf;
762 	va_list args;
763 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
764 
765 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
766 		return;
767 
768 	trace_ext4_error(sb, function, line);
769 	es->s_last_error_ino = cpu_to_le32(ino);
770 	es->s_last_error_block = cpu_to_le64(block);
771 	__save_error_info(sb, function, line);
772 
773 	if (ext4_error_ratelimit(sb)) {
774 		va_start(args, fmt);
775 		vaf.fmt = fmt;
776 		vaf.va = &args;
777 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
778 		       sb->s_id, function, line, grp);
779 		if (ino)
780 			printk(KERN_CONT "inode %lu: ", ino);
781 		if (block)
782 			printk(KERN_CONT "block %llu:",
783 			       (unsigned long long) block);
784 		printk(KERN_CONT "%pV\n", &vaf);
785 		va_end(args);
786 	}
787 
788 	if (test_opt(sb, WARN_ON_ERROR))
789 		WARN_ON_ONCE(1);
790 
791 	if (test_opt(sb, ERRORS_CONT)) {
792 		ext4_commit_super(sb, 0);
793 		return;
794 	}
795 
796 	ext4_unlock_group(sb, grp);
797 	ext4_commit_super(sb, 1);
798 	ext4_handle_error(sb);
799 	/*
800 	 * We only get here in the ERRORS_RO case; relocking the group
801 	 * may be dangerous, but nothing bad will happen since the
802 	 * filesystem will have already been marked read/only and the
803 	 * journal has been aborted.  We return 1 as a hint to callers
804 	 * who might what to use the return value from
805 	 * ext4_grp_locked_error() to distinguish between the
806 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
807 	 * aggressively from the ext4 function in question, with a
808 	 * more appropriate error code.
809 	 */
810 	ext4_lock_group(sb, grp);
811 	return;
812 }
813 
814 void ext4_mark_group_bitmap_corrupted(struct super_block *sb,
815 				     ext4_group_t group,
816 				     unsigned int flags)
817 {
818 	struct ext4_sb_info *sbi = EXT4_SB(sb);
819 	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
820 	struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
821 	int ret;
822 
823 	if (flags & EXT4_GROUP_INFO_BBITMAP_CORRUPT) {
824 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
825 					    &grp->bb_state);
826 		if (!ret)
827 			percpu_counter_sub(&sbi->s_freeclusters_counter,
828 					   grp->bb_free);
829 	}
830 
831 	if (flags & EXT4_GROUP_INFO_IBITMAP_CORRUPT) {
832 		ret = ext4_test_and_set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT,
833 					    &grp->bb_state);
834 		if (!ret && gdp) {
835 			int count;
836 
837 			count = ext4_free_inodes_count(sb, gdp);
838 			percpu_counter_sub(&sbi->s_freeinodes_counter,
839 					   count);
840 		}
841 	}
842 }
843 
844 void ext4_update_dynamic_rev(struct super_block *sb)
845 {
846 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
847 
848 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
849 		return;
850 
851 	ext4_warning(sb,
852 		     "updating to rev %d because of new feature flag, "
853 		     "running e2fsck is recommended",
854 		     EXT4_DYNAMIC_REV);
855 
856 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
857 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
858 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
859 	/* leave es->s_feature_*compat flags alone */
860 	/* es->s_uuid will be set by e2fsck if empty */
861 
862 	/*
863 	 * The rest of the superblock fields should be zero, and if not it
864 	 * means they are likely already in use, so leave them alone.  We
865 	 * can leave it up to e2fsck to clean up any inconsistencies there.
866 	 */
867 }
868 
869 /*
870  * Open the external journal device
871  */
872 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
873 {
874 	struct block_device *bdev;
875 	char b[BDEVNAME_SIZE];
876 
877 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
878 	if (IS_ERR(bdev))
879 		goto fail;
880 	return bdev;
881 
882 fail:
883 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
884 			__bdevname(dev, b), PTR_ERR(bdev));
885 	return NULL;
886 }
887 
888 /*
889  * Release the journal device
890  */
891 static void ext4_blkdev_put(struct block_device *bdev)
892 {
893 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
894 }
895 
896 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
897 {
898 	struct block_device *bdev;
899 	bdev = sbi->journal_bdev;
900 	if (bdev) {
901 		ext4_blkdev_put(bdev);
902 		sbi->journal_bdev = NULL;
903 	}
904 }
905 
906 static inline struct inode *orphan_list_entry(struct list_head *l)
907 {
908 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
909 }
910 
911 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
912 {
913 	struct list_head *l;
914 
915 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
916 		 le32_to_cpu(sbi->s_es->s_last_orphan));
917 
918 	printk(KERN_ERR "sb_info orphan list:\n");
919 	list_for_each(l, &sbi->s_orphan) {
920 		struct inode *inode = orphan_list_entry(l);
921 		printk(KERN_ERR "  "
922 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
923 		       inode->i_sb->s_id, inode->i_ino, inode,
924 		       inode->i_mode, inode->i_nlink,
925 		       NEXT_ORPHAN(inode));
926 	}
927 }
928 
929 #ifdef CONFIG_QUOTA
930 static int ext4_quota_off(struct super_block *sb, int type);
931 
932 static inline void ext4_quota_off_umount(struct super_block *sb)
933 {
934 	int type;
935 
936 	/* Use our quota_off function to clear inode flags etc. */
937 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
938 		ext4_quota_off(sb, type);
939 }
940 
941 /*
942  * This is a helper function which is used in the mount/remount
943  * codepaths (which holds s_umount) to fetch the quota file name.
944  */
945 static inline char *get_qf_name(struct super_block *sb,
946 				struct ext4_sb_info *sbi,
947 				int type)
948 {
949 	return rcu_dereference_protected(sbi->s_qf_names[type],
950 					 lockdep_is_held(&sb->s_umount));
951 }
952 #else
953 static inline void ext4_quota_off_umount(struct super_block *sb)
954 {
955 }
956 #endif
957 
958 static void ext4_put_super(struct super_block *sb)
959 {
960 	struct ext4_sb_info *sbi = EXT4_SB(sb);
961 	struct ext4_super_block *es = sbi->s_es;
962 	int aborted = 0;
963 	int i, err;
964 
965 	ext4_unregister_li_request(sb);
966 	ext4_quota_off_umount(sb);
967 
968 	destroy_workqueue(sbi->rsv_conversion_wq);
969 
970 	if (sbi->s_journal) {
971 		aborted = is_journal_aborted(sbi->s_journal);
972 		err = jbd2_journal_destroy(sbi->s_journal);
973 		sbi->s_journal = NULL;
974 		if ((err < 0) && !aborted)
975 			ext4_abort(sb, "Couldn't clean up the journal");
976 	}
977 
978 	ext4_unregister_sysfs(sb);
979 	ext4_es_unregister_shrinker(sbi);
980 	del_timer_sync(&sbi->s_err_report);
981 	ext4_release_system_zone(sb);
982 	ext4_mb_release(sb);
983 	ext4_ext_release(sb);
984 
985 	if (!sb_rdonly(sb) && !aborted) {
986 		ext4_clear_feature_journal_needs_recovery(sb);
987 		es->s_state = cpu_to_le16(sbi->s_mount_state);
988 	}
989 	if (!sb_rdonly(sb))
990 		ext4_commit_super(sb, 1);
991 
992 	for (i = 0; i < sbi->s_gdb_count; i++)
993 		brelse(sbi->s_group_desc[i]);
994 	kvfree(sbi->s_group_desc);
995 	kvfree(sbi->s_flex_groups);
996 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
997 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
998 	percpu_counter_destroy(&sbi->s_dirs_counter);
999 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
1000 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
1001 #ifdef CONFIG_QUOTA
1002 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
1003 		kfree(get_qf_name(sb, sbi, i));
1004 #endif
1005 
1006 	/* Debugging code just in case the in-memory inode orphan list
1007 	 * isn't empty.  The on-disk one can be non-empty if we've
1008 	 * detected an error and taken the fs readonly, but the
1009 	 * in-memory list had better be clean by this point. */
1010 	if (!list_empty(&sbi->s_orphan))
1011 		dump_orphan_list(sb, sbi);
1012 	J_ASSERT(list_empty(&sbi->s_orphan));
1013 
1014 	sync_blockdev(sb->s_bdev);
1015 	invalidate_bdev(sb->s_bdev);
1016 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
1017 		/*
1018 		 * Invalidate the journal device's buffers.  We don't want them
1019 		 * floating about in memory - the physical journal device may
1020 		 * hotswapped, and it breaks the `ro-after' testing code.
1021 		 */
1022 		sync_blockdev(sbi->journal_bdev);
1023 		invalidate_bdev(sbi->journal_bdev);
1024 		ext4_blkdev_remove(sbi);
1025 	}
1026 
1027 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
1028 	sbi->s_ea_inode_cache = NULL;
1029 
1030 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
1031 	sbi->s_ea_block_cache = NULL;
1032 
1033 	if (sbi->s_mmp_tsk)
1034 		kthread_stop(sbi->s_mmp_tsk);
1035 	brelse(sbi->s_sbh);
1036 	sb->s_fs_info = NULL;
1037 	/*
1038 	 * Now that we are completely done shutting down the
1039 	 * superblock, we need to actually destroy the kobject.
1040 	 */
1041 	kobject_put(&sbi->s_kobj);
1042 	wait_for_completion(&sbi->s_kobj_unregister);
1043 	if (sbi->s_chksum_driver)
1044 		crypto_free_shash(sbi->s_chksum_driver);
1045 	kfree(sbi->s_blockgroup_lock);
1046 	fs_put_dax(sbi->s_daxdev);
1047 	kfree(sbi);
1048 }
1049 
1050 static struct kmem_cache *ext4_inode_cachep;
1051 
1052 /*
1053  * Called inside transaction, so use GFP_NOFS
1054  */
1055 static struct inode *ext4_alloc_inode(struct super_block *sb)
1056 {
1057 	struct ext4_inode_info *ei;
1058 
1059 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
1060 	if (!ei)
1061 		return NULL;
1062 
1063 	inode_set_iversion(&ei->vfs_inode, 1);
1064 	spin_lock_init(&ei->i_raw_lock);
1065 	INIT_LIST_HEAD(&ei->i_prealloc_list);
1066 	spin_lock_init(&ei->i_prealloc_lock);
1067 	ext4_es_init_tree(&ei->i_es_tree);
1068 	rwlock_init(&ei->i_es_lock);
1069 	INIT_LIST_HEAD(&ei->i_es_list);
1070 	ei->i_es_all_nr = 0;
1071 	ei->i_es_shk_nr = 0;
1072 	ei->i_es_shrink_lblk = 0;
1073 	ei->i_reserved_data_blocks = 0;
1074 	ei->i_da_metadata_calc_len = 0;
1075 	ei->i_da_metadata_calc_last_lblock = 0;
1076 	spin_lock_init(&(ei->i_block_reservation_lock));
1077 	ext4_init_pending_tree(&ei->i_pending_tree);
1078 #ifdef CONFIG_QUOTA
1079 	ei->i_reserved_quota = 0;
1080 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
1081 #endif
1082 	ei->jinode = NULL;
1083 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
1084 	spin_lock_init(&ei->i_completed_io_lock);
1085 	ei->i_sync_tid = 0;
1086 	ei->i_datasync_tid = 0;
1087 	atomic_set(&ei->i_unwritten, 0);
1088 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1089 	return &ei->vfs_inode;
1090 }
1091 
1092 static int ext4_drop_inode(struct inode *inode)
1093 {
1094 	int drop = generic_drop_inode(inode);
1095 
1096 	trace_ext4_drop_inode(inode, drop);
1097 	return drop;
1098 }
1099 
1100 static void ext4_i_callback(struct rcu_head *head)
1101 {
1102 	struct inode *inode = container_of(head, struct inode, i_rcu);
1103 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1104 }
1105 
1106 static void ext4_destroy_inode(struct inode *inode)
1107 {
1108 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1109 		ext4_msg(inode->i_sb, KERN_ERR,
1110 			 "Inode %lu (%p): orphan list check failed!",
1111 			 inode->i_ino, EXT4_I(inode));
1112 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1113 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1114 				true);
1115 		dump_stack();
1116 	}
1117 	call_rcu(&inode->i_rcu, ext4_i_callback);
1118 }
1119 
1120 static void init_once(void *foo)
1121 {
1122 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1123 
1124 	INIT_LIST_HEAD(&ei->i_orphan);
1125 	init_rwsem(&ei->xattr_sem);
1126 	init_rwsem(&ei->i_data_sem);
1127 	init_rwsem(&ei->i_mmap_sem);
1128 	inode_init_once(&ei->vfs_inode);
1129 }
1130 
1131 static int __init init_inodecache(void)
1132 {
1133 	ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache",
1134 				sizeof(struct ext4_inode_info), 0,
1135 				(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
1136 					SLAB_ACCOUNT),
1137 				offsetof(struct ext4_inode_info, i_data),
1138 				sizeof_field(struct ext4_inode_info, i_data),
1139 				init_once);
1140 	if (ext4_inode_cachep == NULL)
1141 		return -ENOMEM;
1142 	return 0;
1143 }
1144 
1145 static void destroy_inodecache(void)
1146 {
1147 	/*
1148 	 * Make sure all delayed rcu free inodes are flushed before we
1149 	 * destroy cache.
1150 	 */
1151 	rcu_barrier();
1152 	kmem_cache_destroy(ext4_inode_cachep);
1153 }
1154 
1155 void ext4_clear_inode(struct inode *inode)
1156 {
1157 	invalidate_inode_buffers(inode);
1158 	clear_inode(inode);
1159 	dquot_drop(inode);
1160 	ext4_discard_preallocations(inode);
1161 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1162 	if (EXT4_I(inode)->jinode) {
1163 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1164 					       EXT4_I(inode)->jinode);
1165 		jbd2_free_inode(EXT4_I(inode)->jinode);
1166 		EXT4_I(inode)->jinode = NULL;
1167 	}
1168 	fscrypt_put_encryption_info(inode);
1169 }
1170 
1171 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1172 					u64 ino, u32 generation)
1173 {
1174 	struct inode *inode;
1175 
1176 	/*
1177 	 * Currently we don't know the generation for parent directory, so
1178 	 * a generation of 0 means "accept any"
1179 	 */
1180 	inode = ext4_iget(sb, ino, EXT4_IGET_HANDLE);
1181 	if (IS_ERR(inode))
1182 		return ERR_CAST(inode);
1183 	if (generation && inode->i_generation != generation) {
1184 		iput(inode);
1185 		return ERR_PTR(-ESTALE);
1186 	}
1187 
1188 	return inode;
1189 }
1190 
1191 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1192 					int fh_len, int fh_type)
1193 {
1194 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1195 				    ext4_nfs_get_inode);
1196 }
1197 
1198 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1199 					int fh_len, int fh_type)
1200 {
1201 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1202 				    ext4_nfs_get_inode);
1203 }
1204 
1205 static int ext4_nfs_commit_metadata(struct inode *inode)
1206 {
1207 	struct writeback_control wbc = {
1208 		.sync_mode = WB_SYNC_ALL
1209 	};
1210 
1211 	trace_ext4_nfs_commit_metadata(inode);
1212 	return ext4_write_inode(inode, &wbc);
1213 }
1214 
1215 /*
1216  * Try to release metadata pages (indirect blocks, directories) which are
1217  * mapped via the block device.  Since these pages could have journal heads
1218  * which would prevent try_to_free_buffers() from freeing them, we must use
1219  * jbd2 layer's try_to_free_buffers() function to release them.
1220  */
1221 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1222 				 gfp_t wait)
1223 {
1224 	journal_t *journal = EXT4_SB(sb)->s_journal;
1225 
1226 	WARN_ON(PageChecked(page));
1227 	if (!page_has_buffers(page))
1228 		return 0;
1229 	if (journal)
1230 		return jbd2_journal_try_to_free_buffers(journal, page,
1231 						wait & ~__GFP_DIRECT_RECLAIM);
1232 	return try_to_free_buffers(page);
1233 }
1234 
1235 #ifdef CONFIG_FS_ENCRYPTION
1236 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1237 {
1238 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1239 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1240 }
1241 
1242 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1243 							void *fs_data)
1244 {
1245 	handle_t *handle = fs_data;
1246 	int res, res2, credits, retries = 0;
1247 
1248 	/*
1249 	 * Encrypting the root directory is not allowed because e2fsck expects
1250 	 * lost+found to exist and be unencrypted, and encrypting the root
1251 	 * directory would imply encrypting the lost+found directory as well as
1252 	 * the filename "lost+found" itself.
1253 	 */
1254 	if (inode->i_ino == EXT4_ROOT_INO)
1255 		return -EPERM;
1256 
1257 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1258 		return -EINVAL;
1259 
1260 	res = ext4_convert_inline_data(inode);
1261 	if (res)
1262 		return res;
1263 
1264 	/*
1265 	 * If a journal handle was specified, then the encryption context is
1266 	 * being set on a new inode via inheritance and is part of a larger
1267 	 * transaction to create the inode.  Otherwise the encryption context is
1268 	 * being set on an existing inode in its own transaction.  Only in the
1269 	 * latter case should the "retry on ENOSPC" logic be used.
1270 	 */
1271 
1272 	if (handle) {
1273 		res = ext4_xattr_set_handle(handle, inode,
1274 					    EXT4_XATTR_INDEX_ENCRYPTION,
1275 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1276 					    ctx, len, 0);
1277 		if (!res) {
1278 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1279 			ext4_clear_inode_state(inode,
1280 					EXT4_STATE_MAY_INLINE_DATA);
1281 			/*
1282 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1283 			 * S_DAX may be disabled
1284 			 */
1285 			ext4_set_inode_flags(inode);
1286 		}
1287 		return res;
1288 	}
1289 
1290 	res = dquot_initialize(inode);
1291 	if (res)
1292 		return res;
1293 retry:
1294 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1295 				     &credits);
1296 	if (res)
1297 		return res;
1298 
1299 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1300 	if (IS_ERR(handle))
1301 		return PTR_ERR(handle);
1302 
1303 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1304 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1305 				    ctx, len, 0);
1306 	if (!res) {
1307 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1308 		/*
1309 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1310 		 * S_DAX may be disabled
1311 		 */
1312 		ext4_set_inode_flags(inode);
1313 		res = ext4_mark_inode_dirty(handle, inode);
1314 		if (res)
1315 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1316 	}
1317 	res2 = ext4_journal_stop(handle);
1318 
1319 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1320 		goto retry;
1321 	if (!res)
1322 		res = res2;
1323 	return res;
1324 }
1325 
1326 static bool ext4_dummy_context(struct inode *inode)
1327 {
1328 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1329 }
1330 
1331 static const struct fscrypt_operations ext4_cryptops = {
1332 	.key_prefix		= "ext4:",
1333 	.get_context		= ext4_get_context,
1334 	.set_context		= ext4_set_context,
1335 	.dummy_context		= ext4_dummy_context,
1336 	.empty_dir		= ext4_empty_dir,
1337 	.max_namelen		= EXT4_NAME_LEN,
1338 };
1339 #endif
1340 
1341 #ifdef CONFIG_QUOTA
1342 static const char * const quotatypes[] = INITQFNAMES;
1343 #define QTYPE2NAME(t) (quotatypes[t])
1344 
1345 static int ext4_write_dquot(struct dquot *dquot);
1346 static int ext4_acquire_dquot(struct dquot *dquot);
1347 static int ext4_release_dquot(struct dquot *dquot);
1348 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1349 static int ext4_write_info(struct super_block *sb, int type);
1350 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1351 			 const struct path *path);
1352 static int ext4_quota_on_mount(struct super_block *sb, int type);
1353 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1354 			       size_t len, loff_t off);
1355 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1356 				const char *data, size_t len, loff_t off);
1357 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1358 			     unsigned int flags);
1359 static int ext4_enable_quotas(struct super_block *sb);
1360 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1361 
1362 static struct dquot **ext4_get_dquots(struct inode *inode)
1363 {
1364 	return EXT4_I(inode)->i_dquot;
1365 }
1366 
1367 static const struct dquot_operations ext4_quota_operations = {
1368 	.get_reserved_space	= ext4_get_reserved_space,
1369 	.write_dquot		= ext4_write_dquot,
1370 	.acquire_dquot		= ext4_acquire_dquot,
1371 	.release_dquot		= ext4_release_dquot,
1372 	.mark_dirty		= ext4_mark_dquot_dirty,
1373 	.write_info		= ext4_write_info,
1374 	.alloc_dquot		= dquot_alloc,
1375 	.destroy_dquot		= dquot_destroy,
1376 	.get_projid		= ext4_get_projid,
1377 	.get_inode_usage	= ext4_get_inode_usage,
1378 	.get_next_id		= ext4_get_next_id,
1379 };
1380 
1381 static const struct quotactl_ops ext4_qctl_operations = {
1382 	.quota_on	= ext4_quota_on,
1383 	.quota_off	= ext4_quota_off,
1384 	.quota_sync	= dquot_quota_sync,
1385 	.get_state	= dquot_get_state,
1386 	.set_info	= dquot_set_dqinfo,
1387 	.get_dqblk	= dquot_get_dqblk,
1388 	.set_dqblk	= dquot_set_dqblk,
1389 	.get_nextdqblk	= dquot_get_next_dqblk,
1390 };
1391 #endif
1392 
1393 static const struct super_operations ext4_sops = {
1394 	.alloc_inode	= ext4_alloc_inode,
1395 	.destroy_inode	= ext4_destroy_inode,
1396 	.write_inode	= ext4_write_inode,
1397 	.dirty_inode	= ext4_dirty_inode,
1398 	.drop_inode	= ext4_drop_inode,
1399 	.evict_inode	= ext4_evict_inode,
1400 	.put_super	= ext4_put_super,
1401 	.sync_fs	= ext4_sync_fs,
1402 	.freeze_fs	= ext4_freeze,
1403 	.unfreeze_fs	= ext4_unfreeze,
1404 	.statfs		= ext4_statfs,
1405 	.remount_fs	= ext4_remount,
1406 	.show_options	= ext4_show_options,
1407 #ifdef CONFIG_QUOTA
1408 	.quota_read	= ext4_quota_read,
1409 	.quota_write	= ext4_quota_write,
1410 	.get_dquots	= ext4_get_dquots,
1411 #endif
1412 	.bdev_try_to_free_page = bdev_try_to_free_page,
1413 };
1414 
1415 static const struct export_operations ext4_export_ops = {
1416 	.fh_to_dentry = ext4_fh_to_dentry,
1417 	.fh_to_parent = ext4_fh_to_parent,
1418 	.get_parent = ext4_get_parent,
1419 	.commit_metadata = ext4_nfs_commit_metadata,
1420 };
1421 
1422 enum {
1423 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1424 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1425 	Opt_nouid32, Opt_debug, Opt_removed,
1426 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1427 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1428 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1429 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1430 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1431 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1432 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1433 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1434 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1435 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1436 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1437 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1438 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1439 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1440 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1441 	Opt_dioread_nolock, Opt_dioread_lock,
1442 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1443 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1444 };
1445 
1446 static const match_table_t tokens = {
1447 	{Opt_bsd_df, "bsddf"},
1448 	{Opt_minix_df, "minixdf"},
1449 	{Opt_grpid, "grpid"},
1450 	{Opt_grpid, "bsdgroups"},
1451 	{Opt_nogrpid, "nogrpid"},
1452 	{Opt_nogrpid, "sysvgroups"},
1453 	{Opt_resgid, "resgid=%u"},
1454 	{Opt_resuid, "resuid=%u"},
1455 	{Opt_sb, "sb=%u"},
1456 	{Opt_err_cont, "errors=continue"},
1457 	{Opt_err_panic, "errors=panic"},
1458 	{Opt_err_ro, "errors=remount-ro"},
1459 	{Opt_nouid32, "nouid32"},
1460 	{Opt_debug, "debug"},
1461 	{Opt_removed, "oldalloc"},
1462 	{Opt_removed, "orlov"},
1463 	{Opt_user_xattr, "user_xattr"},
1464 	{Opt_nouser_xattr, "nouser_xattr"},
1465 	{Opt_acl, "acl"},
1466 	{Opt_noacl, "noacl"},
1467 	{Opt_noload, "norecovery"},
1468 	{Opt_noload, "noload"},
1469 	{Opt_removed, "nobh"},
1470 	{Opt_removed, "bh"},
1471 	{Opt_commit, "commit=%u"},
1472 	{Opt_min_batch_time, "min_batch_time=%u"},
1473 	{Opt_max_batch_time, "max_batch_time=%u"},
1474 	{Opt_journal_dev, "journal_dev=%u"},
1475 	{Opt_journal_path, "journal_path=%s"},
1476 	{Opt_journal_checksum, "journal_checksum"},
1477 	{Opt_nojournal_checksum, "nojournal_checksum"},
1478 	{Opt_journal_async_commit, "journal_async_commit"},
1479 	{Opt_abort, "abort"},
1480 	{Opt_data_journal, "data=journal"},
1481 	{Opt_data_ordered, "data=ordered"},
1482 	{Opt_data_writeback, "data=writeback"},
1483 	{Opt_data_err_abort, "data_err=abort"},
1484 	{Opt_data_err_ignore, "data_err=ignore"},
1485 	{Opt_offusrjquota, "usrjquota="},
1486 	{Opt_usrjquota, "usrjquota=%s"},
1487 	{Opt_offgrpjquota, "grpjquota="},
1488 	{Opt_grpjquota, "grpjquota=%s"},
1489 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1490 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1491 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1492 	{Opt_grpquota, "grpquota"},
1493 	{Opt_noquota, "noquota"},
1494 	{Opt_quota, "quota"},
1495 	{Opt_usrquota, "usrquota"},
1496 	{Opt_prjquota, "prjquota"},
1497 	{Opt_barrier, "barrier=%u"},
1498 	{Opt_barrier, "barrier"},
1499 	{Opt_nobarrier, "nobarrier"},
1500 	{Opt_i_version, "i_version"},
1501 	{Opt_dax, "dax"},
1502 	{Opt_stripe, "stripe=%u"},
1503 	{Opt_delalloc, "delalloc"},
1504 	{Opt_warn_on_error, "warn_on_error"},
1505 	{Opt_nowarn_on_error, "nowarn_on_error"},
1506 	{Opt_lazytime, "lazytime"},
1507 	{Opt_nolazytime, "nolazytime"},
1508 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1509 	{Opt_nodelalloc, "nodelalloc"},
1510 	{Opt_removed, "mblk_io_submit"},
1511 	{Opt_removed, "nomblk_io_submit"},
1512 	{Opt_block_validity, "block_validity"},
1513 	{Opt_noblock_validity, "noblock_validity"},
1514 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1515 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1516 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1517 	{Opt_auto_da_alloc, "auto_da_alloc"},
1518 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1519 	{Opt_dioread_nolock, "dioread_nolock"},
1520 	{Opt_dioread_lock, "dioread_lock"},
1521 	{Opt_discard, "discard"},
1522 	{Opt_nodiscard, "nodiscard"},
1523 	{Opt_init_itable, "init_itable=%u"},
1524 	{Opt_init_itable, "init_itable"},
1525 	{Opt_noinit_itable, "noinit_itable"},
1526 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1527 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1528 	{Opt_nombcache, "nombcache"},
1529 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1530 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1531 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1532 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1533 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1534 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1535 	{Opt_err, NULL},
1536 };
1537 
1538 static ext4_fsblk_t get_sb_block(void **data)
1539 {
1540 	ext4_fsblk_t	sb_block;
1541 	char		*options = (char *) *data;
1542 
1543 	if (!options || strncmp(options, "sb=", 3) != 0)
1544 		return 1;	/* Default location */
1545 
1546 	options += 3;
1547 	/* TODO: use simple_strtoll with >32bit ext4 */
1548 	sb_block = simple_strtoul(options, &options, 0);
1549 	if (*options && *options != ',') {
1550 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1551 		       (char *) *data);
1552 		return 1;
1553 	}
1554 	if (*options == ',')
1555 		options++;
1556 	*data = (void *) options;
1557 
1558 	return sb_block;
1559 }
1560 
1561 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1562 static const char deprecated_msg[] =
1563 	"Mount option \"%s\" will be removed by %s\n"
1564 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1565 
1566 #ifdef CONFIG_QUOTA
1567 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1568 {
1569 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1570 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1571 	int ret = -1;
1572 
1573 	if (sb_any_quota_loaded(sb) && !old_qname) {
1574 		ext4_msg(sb, KERN_ERR,
1575 			"Cannot change journaled "
1576 			"quota options when quota turned on");
1577 		return -1;
1578 	}
1579 	if (ext4_has_feature_quota(sb)) {
1580 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1581 			 "ignored when QUOTA feature is enabled");
1582 		return 1;
1583 	}
1584 	qname = match_strdup(args);
1585 	if (!qname) {
1586 		ext4_msg(sb, KERN_ERR,
1587 			"Not enough memory for storing quotafile name");
1588 		return -1;
1589 	}
1590 	if (old_qname) {
1591 		if (strcmp(old_qname, qname) == 0)
1592 			ret = 1;
1593 		else
1594 			ext4_msg(sb, KERN_ERR,
1595 				 "%s quota file already specified",
1596 				 QTYPE2NAME(qtype));
1597 		goto errout;
1598 	}
1599 	if (strchr(qname, '/')) {
1600 		ext4_msg(sb, KERN_ERR,
1601 			"quotafile must be on filesystem root");
1602 		goto errout;
1603 	}
1604 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1605 	set_opt(sb, QUOTA);
1606 	return 1;
1607 errout:
1608 	kfree(qname);
1609 	return ret;
1610 }
1611 
1612 static int clear_qf_name(struct super_block *sb, int qtype)
1613 {
1614 
1615 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1616 	char *old_qname = get_qf_name(sb, sbi, qtype);
1617 
1618 	if (sb_any_quota_loaded(sb) && old_qname) {
1619 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1620 			" when quota turned on");
1621 		return -1;
1622 	}
1623 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1624 	synchronize_rcu();
1625 	kfree(old_qname);
1626 	return 1;
1627 }
1628 #endif
1629 
1630 #define MOPT_SET	0x0001
1631 #define MOPT_CLEAR	0x0002
1632 #define MOPT_NOSUPPORT	0x0004
1633 #define MOPT_EXPLICIT	0x0008
1634 #define MOPT_CLEAR_ERR	0x0010
1635 #define MOPT_GTE0	0x0020
1636 #ifdef CONFIG_QUOTA
1637 #define MOPT_Q		0
1638 #define MOPT_QFMT	0x0040
1639 #else
1640 #define MOPT_Q		MOPT_NOSUPPORT
1641 #define MOPT_QFMT	MOPT_NOSUPPORT
1642 #endif
1643 #define MOPT_DATAJ	0x0080
1644 #define MOPT_NO_EXT2	0x0100
1645 #define MOPT_NO_EXT3	0x0200
1646 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1647 #define MOPT_STRING	0x0400
1648 
1649 static const struct mount_opts {
1650 	int	token;
1651 	int	mount_opt;
1652 	int	flags;
1653 } ext4_mount_opts[] = {
1654 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1655 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1656 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1657 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1658 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1659 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1660 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1661 	 MOPT_EXT4_ONLY | MOPT_SET},
1662 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1663 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1664 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1665 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1666 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1667 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1668 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1669 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1670 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1671 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1672 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1673 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1674 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1675 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1676 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1677 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1678 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1679 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1680 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1681 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1682 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1683 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1684 	 MOPT_NO_EXT2},
1685 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1686 	 MOPT_NO_EXT2},
1687 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1688 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1689 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1690 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1691 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1692 	{Opt_commit, 0, MOPT_GTE0},
1693 	{Opt_max_batch_time, 0, MOPT_GTE0},
1694 	{Opt_min_batch_time, 0, MOPT_GTE0},
1695 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1696 	{Opt_init_itable, 0, MOPT_GTE0},
1697 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1698 	{Opt_stripe, 0, MOPT_GTE0},
1699 	{Opt_resuid, 0, MOPT_GTE0},
1700 	{Opt_resgid, 0, MOPT_GTE0},
1701 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1702 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1703 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1704 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1705 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1706 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1707 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1708 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1709 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1710 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1711 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1712 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1713 #else
1714 	{Opt_acl, 0, MOPT_NOSUPPORT},
1715 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1716 #endif
1717 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1718 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1719 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1720 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1721 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1722 							MOPT_SET | MOPT_Q},
1723 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1724 							MOPT_SET | MOPT_Q},
1725 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1726 							MOPT_SET | MOPT_Q},
1727 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1728 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1729 							MOPT_CLEAR | MOPT_Q},
1730 	{Opt_usrjquota, 0, MOPT_Q},
1731 	{Opt_grpjquota, 0, MOPT_Q},
1732 	{Opt_offusrjquota, 0, MOPT_Q},
1733 	{Opt_offgrpjquota, 0, MOPT_Q},
1734 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1735 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1736 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1737 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1738 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1739 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1740 	{Opt_err, 0, 0}
1741 };
1742 
1743 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1744 			    substring_t *args, unsigned long *journal_devnum,
1745 			    unsigned int *journal_ioprio, int is_remount)
1746 {
1747 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1748 	const struct mount_opts *m;
1749 	kuid_t uid;
1750 	kgid_t gid;
1751 	int arg = 0;
1752 
1753 #ifdef CONFIG_QUOTA
1754 	if (token == Opt_usrjquota)
1755 		return set_qf_name(sb, USRQUOTA, &args[0]);
1756 	else if (token == Opt_grpjquota)
1757 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1758 	else if (token == Opt_offusrjquota)
1759 		return clear_qf_name(sb, USRQUOTA);
1760 	else if (token == Opt_offgrpjquota)
1761 		return clear_qf_name(sb, GRPQUOTA);
1762 #endif
1763 	switch (token) {
1764 	case Opt_noacl:
1765 	case Opt_nouser_xattr:
1766 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1767 		break;
1768 	case Opt_sb:
1769 		return 1;	/* handled by get_sb_block() */
1770 	case Opt_removed:
1771 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1772 		return 1;
1773 	case Opt_abort:
1774 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1775 		return 1;
1776 	case Opt_i_version:
1777 		sb->s_flags |= SB_I_VERSION;
1778 		return 1;
1779 	case Opt_lazytime:
1780 		sb->s_flags |= SB_LAZYTIME;
1781 		return 1;
1782 	case Opt_nolazytime:
1783 		sb->s_flags &= ~SB_LAZYTIME;
1784 		return 1;
1785 	}
1786 
1787 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1788 		if (token == m->token)
1789 			break;
1790 
1791 	if (m->token == Opt_err) {
1792 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1793 			 "or missing value", opt);
1794 		return -1;
1795 	}
1796 
1797 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1798 		ext4_msg(sb, KERN_ERR,
1799 			 "Mount option \"%s\" incompatible with ext2", opt);
1800 		return -1;
1801 	}
1802 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1803 		ext4_msg(sb, KERN_ERR,
1804 			 "Mount option \"%s\" incompatible with ext3", opt);
1805 		return -1;
1806 	}
1807 
1808 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1809 		return -1;
1810 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1811 		return -1;
1812 	if (m->flags & MOPT_EXPLICIT) {
1813 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1814 			set_opt2(sb, EXPLICIT_DELALLOC);
1815 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1816 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1817 		} else
1818 			return -1;
1819 	}
1820 	if (m->flags & MOPT_CLEAR_ERR)
1821 		clear_opt(sb, ERRORS_MASK);
1822 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1823 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1824 			 "options when quota turned on");
1825 		return -1;
1826 	}
1827 
1828 	if (m->flags & MOPT_NOSUPPORT) {
1829 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1830 	} else if (token == Opt_commit) {
1831 		if (arg == 0)
1832 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1833 		sbi->s_commit_interval = HZ * arg;
1834 	} else if (token == Opt_debug_want_extra_isize) {
1835 		sbi->s_want_extra_isize = arg;
1836 	} else if (token == Opt_max_batch_time) {
1837 		sbi->s_max_batch_time = arg;
1838 	} else if (token == Opt_min_batch_time) {
1839 		sbi->s_min_batch_time = arg;
1840 	} else if (token == Opt_inode_readahead_blks) {
1841 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1842 			ext4_msg(sb, KERN_ERR,
1843 				 "EXT4-fs: inode_readahead_blks must be "
1844 				 "0 or a power of 2 smaller than 2^31");
1845 			return -1;
1846 		}
1847 		sbi->s_inode_readahead_blks = arg;
1848 	} else if (token == Opt_init_itable) {
1849 		set_opt(sb, INIT_INODE_TABLE);
1850 		if (!args->from)
1851 			arg = EXT4_DEF_LI_WAIT_MULT;
1852 		sbi->s_li_wait_mult = arg;
1853 	} else if (token == Opt_max_dir_size_kb) {
1854 		sbi->s_max_dir_size_kb = arg;
1855 	} else if (token == Opt_stripe) {
1856 		sbi->s_stripe = arg;
1857 	} else if (token == Opt_resuid) {
1858 		uid = make_kuid(current_user_ns(), arg);
1859 		if (!uid_valid(uid)) {
1860 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1861 			return -1;
1862 		}
1863 		sbi->s_resuid = uid;
1864 	} else if (token == Opt_resgid) {
1865 		gid = make_kgid(current_user_ns(), arg);
1866 		if (!gid_valid(gid)) {
1867 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1868 			return -1;
1869 		}
1870 		sbi->s_resgid = gid;
1871 	} else if (token == Opt_journal_dev) {
1872 		if (is_remount) {
1873 			ext4_msg(sb, KERN_ERR,
1874 				 "Cannot specify journal on remount");
1875 			return -1;
1876 		}
1877 		*journal_devnum = arg;
1878 	} else if (token == Opt_journal_path) {
1879 		char *journal_path;
1880 		struct inode *journal_inode;
1881 		struct path path;
1882 		int error;
1883 
1884 		if (is_remount) {
1885 			ext4_msg(sb, KERN_ERR,
1886 				 "Cannot specify journal on remount");
1887 			return -1;
1888 		}
1889 		journal_path = match_strdup(&args[0]);
1890 		if (!journal_path) {
1891 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1892 				"journal device string");
1893 			return -1;
1894 		}
1895 
1896 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1897 		if (error) {
1898 			ext4_msg(sb, KERN_ERR, "error: could not find "
1899 				"journal device path: error %d", error);
1900 			kfree(journal_path);
1901 			return -1;
1902 		}
1903 
1904 		journal_inode = d_inode(path.dentry);
1905 		if (!S_ISBLK(journal_inode->i_mode)) {
1906 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1907 				"is not a block device", journal_path);
1908 			path_put(&path);
1909 			kfree(journal_path);
1910 			return -1;
1911 		}
1912 
1913 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1914 		path_put(&path);
1915 		kfree(journal_path);
1916 	} else if (token == Opt_journal_ioprio) {
1917 		if (arg > 7) {
1918 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1919 				 " (must be 0-7)");
1920 			return -1;
1921 		}
1922 		*journal_ioprio =
1923 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1924 	} else if (token == Opt_test_dummy_encryption) {
1925 #ifdef CONFIG_FS_ENCRYPTION
1926 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1927 		ext4_msg(sb, KERN_WARNING,
1928 			 "Test dummy encryption mode enabled");
1929 #else
1930 		ext4_msg(sb, KERN_WARNING,
1931 			 "Test dummy encryption mount option ignored");
1932 #endif
1933 	} else if (m->flags & MOPT_DATAJ) {
1934 		if (is_remount) {
1935 			if (!sbi->s_journal)
1936 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1937 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1938 				ext4_msg(sb, KERN_ERR,
1939 					 "Cannot change data mode on remount");
1940 				return -1;
1941 			}
1942 		} else {
1943 			clear_opt(sb, DATA_FLAGS);
1944 			sbi->s_mount_opt |= m->mount_opt;
1945 		}
1946 #ifdef CONFIG_QUOTA
1947 	} else if (m->flags & MOPT_QFMT) {
1948 		if (sb_any_quota_loaded(sb) &&
1949 		    sbi->s_jquota_fmt != m->mount_opt) {
1950 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1951 				 "quota options when quota turned on");
1952 			return -1;
1953 		}
1954 		if (ext4_has_feature_quota(sb)) {
1955 			ext4_msg(sb, KERN_INFO,
1956 				 "Quota format mount options ignored "
1957 				 "when QUOTA feature is enabled");
1958 			return 1;
1959 		}
1960 		sbi->s_jquota_fmt = m->mount_opt;
1961 #endif
1962 	} else if (token == Opt_dax) {
1963 #ifdef CONFIG_FS_DAX
1964 		ext4_msg(sb, KERN_WARNING,
1965 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1966 		sbi->s_mount_opt |= m->mount_opt;
1967 #else
1968 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1969 		return -1;
1970 #endif
1971 	} else if (token == Opt_data_err_abort) {
1972 		sbi->s_mount_opt |= m->mount_opt;
1973 	} else if (token == Opt_data_err_ignore) {
1974 		sbi->s_mount_opt &= ~m->mount_opt;
1975 	} else {
1976 		if (!args->from)
1977 			arg = 1;
1978 		if (m->flags & MOPT_CLEAR)
1979 			arg = !arg;
1980 		else if (unlikely(!(m->flags & MOPT_SET))) {
1981 			ext4_msg(sb, KERN_WARNING,
1982 				 "buggy handling of option %s", opt);
1983 			WARN_ON(1);
1984 			return -1;
1985 		}
1986 		if (arg != 0)
1987 			sbi->s_mount_opt |= m->mount_opt;
1988 		else
1989 			sbi->s_mount_opt &= ~m->mount_opt;
1990 	}
1991 	return 1;
1992 }
1993 
1994 static int parse_options(char *options, struct super_block *sb,
1995 			 unsigned long *journal_devnum,
1996 			 unsigned int *journal_ioprio,
1997 			 int is_remount)
1998 {
1999 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2000 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
2001 	substring_t args[MAX_OPT_ARGS];
2002 	int token;
2003 
2004 	if (!options)
2005 		return 1;
2006 
2007 	while ((p = strsep(&options, ",")) != NULL) {
2008 		if (!*p)
2009 			continue;
2010 		/*
2011 		 * Initialize args struct so we know whether arg was
2012 		 * found; some options take optional arguments.
2013 		 */
2014 		args[0].to = args[0].from = NULL;
2015 		token = match_token(p, tokens, args);
2016 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2017 				     journal_ioprio, is_remount) < 0)
2018 			return 0;
2019 	}
2020 #ifdef CONFIG_QUOTA
2021 	/*
2022 	 * We do the test below only for project quotas. 'usrquota' and
2023 	 * 'grpquota' mount options are allowed even without quota feature
2024 	 * to support legacy quotas in quota files.
2025 	 */
2026 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2027 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2028 			 "Cannot enable project quota enforcement.");
2029 		return 0;
2030 	}
2031 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2032 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2033 	if (usr_qf_name || grp_qf_name) {
2034 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2035 			clear_opt(sb, USRQUOTA);
2036 
2037 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2038 			clear_opt(sb, GRPQUOTA);
2039 
2040 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2041 			ext4_msg(sb, KERN_ERR, "old and new quota "
2042 					"format mixing");
2043 			return 0;
2044 		}
2045 
2046 		if (!sbi->s_jquota_fmt) {
2047 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2048 					"not specified");
2049 			return 0;
2050 		}
2051 	}
2052 #endif
2053 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2054 		int blocksize =
2055 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2056 
2057 		if (blocksize < PAGE_SIZE) {
2058 			ext4_msg(sb, KERN_ERR, "can't mount with "
2059 				 "dioread_nolock if block size != PAGE_SIZE");
2060 			return 0;
2061 		}
2062 	}
2063 	return 1;
2064 }
2065 
2066 static inline void ext4_show_quota_options(struct seq_file *seq,
2067 					   struct super_block *sb)
2068 {
2069 #if defined(CONFIG_QUOTA)
2070 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2071 	char *usr_qf_name, *grp_qf_name;
2072 
2073 	if (sbi->s_jquota_fmt) {
2074 		char *fmtname = "";
2075 
2076 		switch (sbi->s_jquota_fmt) {
2077 		case QFMT_VFS_OLD:
2078 			fmtname = "vfsold";
2079 			break;
2080 		case QFMT_VFS_V0:
2081 			fmtname = "vfsv0";
2082 			break;
2083 		case QFMT_VFS_V1:
2084 			fmtname = "vfsv1";
2085 			break;
2086 		}
2087 		seq_printf(seq, ",jqfmt=%s", fmtname);
2088 	}
2089 
2090 	rcu_read_lock();
2091 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2092 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2093 	if (usr_qf_name)
2094 		seq_show_option(seq, "usrjquota", usr_qf_name);
2095 	if (grp_qf_name)
2096 		seq_show_option(seq, "grpjquota", grp_qf_name);
2097 	rcu_read_unlock();
2098 #endif
2099 }
2100 
2101 static const char *token2str(int token)
2102 {
2103 	const struct match_token *t;
2104 
2105 	for (t = tokens; t->token != Opt_err; t++)
2106 		if (t->token == token && !strchr(t->pattern, '='))
2107 			break;
2108 	return t->pattern;
2109 }
2110 
2111 /*
2112  * Show an option if
2113  *  - it's set to a non-default value OR
2114  *  - if the per-sb default is different from the global default
2115  */
2116 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2117 			      int nodefs)
2118 {
2119 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2120 	struct ext4_super_block *es = sbi->s_es;
2121 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2122 	const struct mount_opts *m;
2123 	char sep = nodefs ? '\n' : ',';
2124 
2125 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2126 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2127 
2128 	if (sbi->s_sb_block != 1)
2129 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2130 
2131 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2132 		int want_set = m->flags & MOPT_SET;
2133 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2134 		    (m->flags & MOPT_CLEAR_ERR))
2135 			continue;
2136 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2137 			continue; /* skip if same as the default */
2138 		if ((want_set &&
2139 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2140 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2141 			continue; /* select Opt_noFoo vs Opt_Foo */
2142 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2143 	}
2144 
2145 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2146 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2147 		SEQ_OPTS_PRINT("resuid=%u",
2148 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2149 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2150 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2151 		SEQ_OPTS_PRINT("resgid=%u",
2152 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2153 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2154 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2155 		SEQ_OPTS_PUTS("errors=remount-ro");
2156 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2157 		SEQ_OPTS_PUTS("errors=continue");
2158 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2159 		SEQ_OPTS_PUTS("errors=panic");
2160 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2161 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2162 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2163 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2164 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2165 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2166 	if (sb->s_flags & SB_I_VERSION)
2167 		SEQ_OPTS_PUTS("i_version");
2168 	if (nodefs || sbi->s_stripe)
2169 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2170 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2171 			(sbi->s_mount_opt ^ def_mount_opt)) {
2172 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2173 			SEQ_OPTS_PUTS("data=journal");
2174 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2175 			SEQ_OPTS_PUTS("data=ordered");
2176 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2177 			SEQ_OPTS_PUTS("data=writeback");
2178 	}
2179 	if (nodefs ||
2180 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2181 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2182 			       sbi->s_inode_readahead_blks);
2183 
2184 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2185 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2186 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2187 	if (nodefs || sbi->s_max_dir_size_kb)
2188 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2189 	if (test_opt(sb, DATA_ERR_ABORT))
2190 		SEQ_OPTS_PUTS("data_err=abort");
2191 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2192 		SEQ_OPTS_PUTS("test_dummy_encryption");
2193 
2194 	ext4_show_quota_options(seq, sb);
2195 	return 0;
2196 }
2197 
2198 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2199 {
2200 	return _ext4_show_options(seq, root->d_sb, 0);
2201 }
2202 
2203 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2204 {
2205 	struct super_block *sb = seq->private;
2206 	int rc;
2207 
2208 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2209 	rc = _ext4_show_options(seq, sb, 1);
2210 	seq_puts(seq, "\n");
2211 	return rc;
2212 }
2213 
2214 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2215 			    int read_only)
2216 {
2217 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2218 	int err = 0;
2219 
2220 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2221 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2222 			 "forcing read-only mode");
2223 		err = -EROFS;
2224 	}
2225 	if (read_only)
2226 		goto done;
2227 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2228 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2229 			 "running e2fsck is recommended");
2230 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2231 		ext4_msg(sb, KERN_WARNING,
2232 			 "warning: mounting fs with errors, "
2233 			 "running e2fsck is recommended");
2234 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2235 		 le16_to_cpu(es->s_mnt_count) >=
2236 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2237 		ext4_msg(sb, KERN_WARNING,
2238 			 "warning: maximal mount count reached, "
2239 			 "running e2fsck is recommended");
2240 	else if (le32_to_cpu(es->s_checkinterval) &&
2241 		 (ext4_get_tstamp(es, s_lastcheck) +
2242 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2243 		ext4_msg(sb, KERN_WARNING,
2244 			 "warning: checktime reached, "
2245 			 "running e2fsck is recommended");
2246 	if (!sbi->s_journal)
2247 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2248 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2249 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2250 	le16_add_cpu(&es->s_mnt_count, 1);
2251 	ext4_update_tstamp(es, s_mtime);
2252 	if (sbi->s_journal)
2253 		ext4_set_feature_journal_needs_recovery(sb);
2254 
2255 	err = ext4_commit_super(sb, 1);
2256 done:
2257 	if (test_opt(sb, DEBUG))
2258 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2259 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2260 			sb->s_blocksize,
2261 			sbi->s_groups_count,
2262 			EXT4_BLOCKS_PER_GROUP(sb),
2263 			EXT4_INODES_PER_GROUP(sb),
2264 			sbi->s_mount_opt, sbi->s_mount_opt2);
2265 
2266 	cleancache_init_fs(sb);
2267 	return err;
2268 }
2269 
2270 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2271 {
2272 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2273 	struct flex_groups *new_groups;
2274 	int size;
2275 
2276 	if (!sbi->s_log_groups_per_flex)
2277 		return 0;
2278 
2279 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2280 	if (size <= sbi->s_flex_groups_allocated)
2281 		return 0;
2282 
2283 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2284 	new_groups = kvzalloc(size, GFP_KERNEL);
2285 	if (!new_groups) {
2286 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2287 			 size / (int) sizeof(struct flex_groups));
2288 		return -ENOMEM;
2289 	}
2290 
2291 	if (sbi->s_flex_groups) {
2292 		memcpy(new_groups, sbi->s_flex_groups,
2293 		       (sbi->s_flex_groups_allocated *
2294 			sizeof(struct flex_groups)));
2295 		kvfree(sbi->s_flex_groups);
2296 	}
2297 	sbi->s_flex_groups = new_groups;
2298 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2299 	return 0;
2300 }
2301 
2302 static int ext4_fill_flex_info(struct super_block *sb)
2303 {
2304 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2305 	struct ext4_group_desc *gdp = NULL;
2306 	ext4_group_t flex_group;
2307 	int i, err;
2308 
2309 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2310 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2311 		sbi->s_log_groups_per_flex = 0;
2312 		return 1;
2313 	}
2314 
2315 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2316 	if (err)
2317 		goto failed;
2318 
2319 	for (i = 0; i < sbi->s_groups_count; i++) {
2320 		gdp = ext4_get_group_desc(sb, i, NULL);
2321 
2322 		flex_group = ext4_flex_group(sbi, i);
2323 		atomic_add(ext4_free_inodes_count(sb, gdp),
2324 			   &sbi->s_flex_groups[flex_group].free_inodes);
2325 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2326 			     &sbi->s_flex_groups[flex_group].free_clusters);
2327 		atomic_add(ext4_used_dirs_count(sb, gdp),
2328 			   &sbi->s_flex_groups[flex_group].used_dirs);
2329 	}
2330 
2331 	return 1;
2332 failed:
2333 	return 0;
2334 }
2335 
2336 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2337 				   struct ext4_group_desc *gdp)
2338 {
2339 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2340 	__u16 crc = 0;
2341 	__le32 le_group = cpu_to_le32(block_group);
2342 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2343 
2344 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2345 		/* Use new metadata_csum algorithm */
2346 		__u32 csum32;
2347 		__u16 dummy_csum = 0;
2348 
2349 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2350 				     sizeof(le_group));
2351 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2352 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2353 				     sizeof(dummy_csum));
2354 		offset += sizeof(dummy_csum);
2355 		if (offset < sbi->s_desc_size)
2356 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2357 					     sbi->s_desc_size - offset);
2358 
2359 		crc = csum32 & 0xFFFF;
2360 		goto out;
2361 	}
2362 
2363 	/* old crc16 code */
2364 	if (!ext4_has_feature_gdt_csum(sb))
2365 		return 0;
2366 
2367 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2368 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2369 	crc = crc16(crc, (__u8 *)gdp, offset);
2370 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2371 	/* for checksum of struct ext4_group_desc do the rest...*/
2372 	if (ext4_has_feature_64bit(sb) &&
2373 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2374 		crc = crc16(crc, (__u8 *)gdp + offset,
2375 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2376 				offset);
2377 
2378 out:
2379 	return cpu_to_le16(crc);
2380 }
2381 
2382 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2383 				struct ext4_group_desc *gdp)
2384 {
2385 	if (ext4_has_group_desc_csum(sb) &&
2386 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2387 		return 0;
2388 
2389 	return 1;
2390 }
2391 
2392 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2393 			      struct ext4_group_desc *gdp)
2394 {
2395 	if (!ext4_has_group_desc_csum(sb))
2396 		return;
2397 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2398 }
2399 
2400 /* Called at mount-time, super-block is locked */
2401 static int ext4_check_descriptors(struct super_block *sb,
2402 				  ext4_fsblk_t sb_block,
2403 				  ext4_group_t *first_not_zeroed)
2404 {
2405 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2406 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2407 	ext4_fsblk_t last_block;
2408 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2409 	ext4_fsblk_t block_bitmap;
2410 	ext4_fsblk_t inode_bitmap;
2411 	ext4_fsblk_t inode_table;
2412 	int flexbg_flag = 0;
2413 	ext4_group_t i, grp = sbi->s_groups_count;
2414 
2415 	if (ext4_has_feature_flex_bg(sb))
2416 		flexbg_flag = 1;
2417 
2418 	ext4_debug("Checking group descriptors");
2419 
2420 	for (i = 0; i < sbi->s_groups_count; i++) {
2421 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2422 
2423 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2424 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2425 		else
2426 			last_block = first_block +
2427 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2428 
2429 		if ((grp == sbi->s_groups_count) &&
2430 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2431 			grp = i;
2432 
2433 		block_bitmap = ext4_block_bitmap(sb, gdp);
2434 		if (block_bitmap == sb_block) {
2435 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2436 				 "Block bitmap for group %u overlaps "
2437 				 "superblock", i);
2438 			if (!sb_rdonly(sb))
2439 				return 0;
2440 		}
2441 		if (block_bitmap >= sb_block + 1 &&
2442 		    block_bitmap <= last_bg_block) {
2443 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2444 				 "Block bitmap for group %u overlaps "
2445 				 "block group descriptors", i);
2446 			if (!sb_rdonly(sb))
2447 				return 0;
2448 		}
2449 		if (block_bitmap < first_block || block_bitmap > last_block) {
2450 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2451 			       "Block bitmap for group %u not in group "
2452 			       "(block %llu)!", i, block_bitmap);
2453 			return 0;
2454 		}
2455 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2456 		if (inode_bitmap == sb_block) {
2457 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2458 				 "Inode bitmap for group %u overlaps "
2459 				 "superblock", i);
2460 			if (!sb_rdonly(sb))
2461 				return 0;
2462 		}
2463 		if (inode_bitmap >= sb_block + 1 &&
2464 		    inode_bitmap <= last_bg_block) {
2465 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2466 				 "Inode bitmap for group %u overlaps "
2467 				 "block group descriptors", i);
2468 			if (!sb_rdonly(sb))
2469 				return 0;
2470 		}
2471 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2472 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2473 			       "Inode bitmap for group %u not in group "
2474 			       "(block %llu)!", i, inode_bitmap);
2475 			return 0;
2476 		}
2477 		inode_table = ext4_inode_table(sb, gdp);
2478 		if (inode_table == sb_block) {
2479 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2480 				 "Inode table for group %u overlaps "
2481 				 "superblock", i);
2482 			if (!sb_rdonly(sb))
2483 				return 0;
2484 		}
2485 		if (inode_table >= sb_block + 1 &&
2486 		    inode_table <= last_bg_block) {
2487 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2488 				 "Inode table for group %u overlaps "
2489 				 "block group descriptors", i);
2490 			if (!sb_rdonly(sb))
2491 				return 0;
2492 		}
2493 		if (inode_table < first_block ||
2494 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2495 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2496 			       "Inode table for group %u not in group "
2497 			       "(block %llu)!", i, inode_table);
2498 			return 0;
2499 		}
2500 		ext4_lock_group(sb, i);
2501 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2502 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2503 				 "Checksum for group %u failed (%u!=%u)",
2504 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2505 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2506 			if (!sb_rdonly(sb)) {
2507 				ext4_unlock_group(sb, i);
2508 				return 0;
2509 			}
2510 		}
2511 		ext4_unlock_group(sb, i);
2512 		if (!flexbg_flag)
2513 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2514 	}
2515 	if (NULL != first_not_zeroed)
2516 		*first_not_zeroed = grp;
2517 	return 1;
2518 }
2519 
2520 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2521  * the superblock) which were deleted from all directories, but held open by
2522  * a process at the time of a crash.  We walk the list and try to delete these
2523  * inodes at recovery time (only with a read-write filesystem).
2524  *
2525  * In order to keep the orphan inode chain consistent during traversal (in
2526  * case of crash during recovery), we link each inode into the superblock
2527  * orphan list_head and handle it the same way as an inode deletion during
2528  * normal operation (which journals the operations for us).
2529  *
2530  * We only do an iget() and an iput() on each inode, which is very safe if we
2531  * accidentally point at an in-use or already deleted inode.  The worst that
2532  * can happen in this case is that we get a "bit already cleared" message from
2533  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2534  * e2fsck was run on this filesystem, and it must have already done the orphan
2535  * inode cleanup for us, so we can safely abort without any further action.
2536  */
2537 static void ext4_orphan_cleanup(struct super_block *sb,
2538 				struct ext4_super_block *es)
2539 {
2540 	unsigned int s_flags = sb->s_flags;
2541 	int ret, nr_orphans = 0, nr_truncates = 0;
2542 #ifdef CONFIG_QUOTA
2543 	int quota_update = 0;
2544 	int i;
2545 #endif
2546 	if (!es->s_last_orphan) {
2547 		jbd_debug(4, "no orphan inodes to clean up\n");
2548 		return;
2549 	}
2550 
2551 	if (bdev_read_only(sb->s_bdev)) {
2552 		ext4_msg(sb, KERN_ERR, "write access "
2553 			"unavailable, skipping orphan cleanup");
2554 		return;
2555 	}
2556 
2557 	/* Check if feature set would not allow a r/w mount */
2558 	if (!ext4_feature_set_ok(sb, 0)) {
2559 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2560 			 "unknown ROCOMPAT features");
2561 		return;
2562 	}
2563 
2564 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2565 		/* don't clear list on RO mount w/ errors */
2566 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2567 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2568 				  "clearing orphan list.\n");
2569 			es->s_last_orphan = 0;
2570 		}
2571 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2572 		return;
2573 	}
2574 
2575 	if (s_flags & SB_RDONLY) {
2576 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2577 		sb->s_flags &= ~SB_RDONLY;
2578 	}
2579 #ifdef CONFIG_QUOTA
2580 	/* Needed for iput() to work correctly and not trash data */
2581 	sb->s_flags |= SB_ACTIVE;
2582 
2583 	/*
2584 	 * Turn on quotas which were not enabled for read-only mounts if
2585 	 * filesystem has quota feature, so that they are updated correctly.
2586 	 */
2587 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2588 		int ret = ext4_enable_quotas(sb);
2589 
2590 		if (!ret)
2591 			quota_update = 1;
2592 		else
2593 			ext4_msg(sb, KERN_ERR,
2594 				"Cannot turn on quotas: error %d", ret);
2595 	}
2596 
2597 	/* Turn on journaled quotas used for old sytle */
2598 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2599 		if (EXT4_SB(sb)->s_qf_names[i]) {
2600 			int ret = ext4_quota_on_mount(sb, i);
2601 
2602 			if (!ret)
2603 				quota_update = 1;
2604 			else
2605 				ext4_msg(sb, KERN_ERR,
2606 					"Cannot turn on journaled "
2607 					"quota: type %d: error %d", i, ret);
2608 		}
2609 	}
2610 #endif
2611 
2612 	while (es->s_last_orphan) {
2613 		struct inode *inode;
2614 
2615 		/*
2616 		 * We may have encountered an error during cleanup; if
2617 		 * so, skip the rest.
2618 		 */
2619 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2620 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2621 			es->s_last_orphan = 0;
2622 			break;
2623 		}
2624 
2625 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2626 		if (IS_ERR(inode)) {
2627 			es->s_last_orphan = 0;
2628 			break;
2629 		}
2630 
2631 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2632 		dquot_initialize(inode);
2633 		if (inode->i_nlink) {
2634 			if (test_opt(sb, DEBUG))
2635 				ext4_msg(sb, KERN_DEBUG,
2636 					"%s: truncating inode %lu to %lld bytes",
2637 					__func__, inode->i_ino, inode->i_size);
2638 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2639 				  inode->i_ino, inode->i_size);
2640 			inode_lock(inode);
2641 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2642 			ret = ext4_truncate(inode);
2643 			if (ret)
2644 				ext4_std_error(inode->i_sb, ret);
2645 			inode_unlock(inode);
2646 			nr_truncates++;
2647 		} else {
2648 			if (test_opt(sb, DEBUG))
2649 				ext4_msg(sb, KERN_DEBUG,
2650 					"%s: deleting unreferenced inode %lu",
2651 					__func__, inode->i_ino);
2652 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2653 				  inode->i_ino);
2654 			nr_orphans++;
2655 		}
2656 		iput(inode);  /* The delete magic happens here! */
2657 	}
2658 
2659 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2660 
2661 	if (nr_orphans)
2662 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2663 		       PLURAL(nr_orphans));
2664 	if (nr_truncates)
2665 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2666 		       PLURAL(nr_truncates));
2667 #ifdef CONFIG_QUOTA
2668 	/* Turn off quotas if they were enabled for orphan cleanup */
2669 	if (quota_update) {
2670 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2671 			if (sb_dqopt(sb)->files[i])
2672 				dquot_quota_off(sb, i);
2673 		}
2674 	}
2675 #endif
2676 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2677 }
2678 
2679 /*
2680  * Maximal extent format file size.
2681  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2682  * extent format containers, within a sector_t, and within i_blocks
2683  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2684  * so that won't be a limiting factor.
2685  *
2686  * However there is other limiting factor. We do store extents in the form
2687  * of starting block and length, hence the resulting length of the extent
2688  * covering maximum file size must fit into on-disk format containers as
2689  * well. Given that length is always by 1 unit bigger than max unit (because
2690  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2691  *
2692  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2693  */
2694 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2695 {
2696 	loff_t res;
2697 	loff_t upper_limit = MAX_LFS_FILESIZE;
2698 
2699 	/* small i_blocks in vfs inode? */
2700 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2701 		/*
2702 		 * CONFIG_LBDAF is not enabled implies the inode
2703 		 * i_block represent total blocks in 512 bytes
2704 		 * 32 == size of vfs inode i_blocks * 8
2705 		 */
2706 		upper_limit = (1LL << 32) - 1;
2707 
2708 		/* total blocks in file system block size */
2709 		upper_limit >>= (blkbits - 9);
2710 		upper_limit <<= blkbits;
2711 	}
2712 
2713 	/*
2714 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2715 	 * by one fs block, so ee_len can cover the extent of maximum file
2716 	 * size
2717 	 */
2718 	res = (1LL << 32) - 1;
2719 	res <<= blkbits;
2720 
2721 	/* Sanity check against vm- & vfs- imposed limits */
2722 	if (res > upper_limit)
2723 		res = upper_limit;
2724 
2725 	return res;
2726 }
2727 
2728 /*
2729  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2730  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2731  * We need to be 1 filesystem block less than the 2^48 sector limit.
2732  */
2733 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2734 {
2735 	loff_t res = EXT4_NDIR_BLOCKS;
2736 	int meta_blocks;
2737 	loff_t upper_limit;
2738 	/* This is calculated to be the largest file size for a dense, block
2739 	 * mapped file such that the file's total number of 512-byte sectors,
2740 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2741 	 *
2742 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2743 	 * number of 512-byte sectors of the file.
2744 	 */
2745 
2746 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2747 		/*
2748 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2749 		 * the inode i_block field represents total file blocks in
2750 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2751 		 */
2752 		upper_limit = (1LL << 32) - 1;
2753 
2754 		/* total blocks in file system block size */
2755 		upper_limit >>= (bits - 9);
2756 
2757 	} else {
2758 		/*
2759 		 * We use 48 bit ext4_inode i_blocks
2760 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2761 		 * represent total number of blocks in
2762 		 * file system block size
2763 		 */
2764 		upper_limit = (1LL << 48) - 1;
2765 
2766 	}
2767 
2768 	/* indirect blocks */
2769 	meta_blocks = 1;
2770 	/* double indirect blocks */
2771 	meta_blocks += 1 + (1LL << (bits-2));
2772 	/* tripple indirect blocks */
2773 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2774 
2775 	upper_limit -= meta_blocks;
2776 	upper_limit <<= bits;
2777 
2778 	res += 1LL << (bits-2);
2779 	res += 1LL << (2*(bits-2));
2780 	res += 1LL << (3*(bits-2));
2781 	res <<= bits;
2782 	if (res > upper_limit)
2783 		res = upper_limit;
2784 
2785 	if (res > MAX_LFS_FILESIZE)
2786 		res = MAX_LFS_FILESIZE;
2787 
2788 	return res;
2789 }
2790 
2791 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2792 				   ext4_fsblk_t logical_sb_block, int nr)
2793 {
2794 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2795 	ext4_group_t bg, first_meta_bg;
2796 	int has_super = 0;
2797 
2798 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2799 
2800 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2801 		return logical_sb_block + nr + 1;
2802 	bg = sbi->s_desc_per_block * nr;
2803 	if (ext4_bg_has_super(sb, bg))
2804 		has_super = 1;
2805 
2806 	/*
2807 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2808 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2809 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2810 	 * compensate.
2811 	 */
2812 	if (sb->s_blocksize == 1024 && nr == 0 &&
2813 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2814 		has_super++;
2815 
2816 	return (has_super + ext4_group_first_block_no(sb, bg));
2817 }
2818 
2819 /**
2820  * ext4_get_stripe_size: Get the stripe size.
2821  * @sbi: In memory super block info
2822  *
2823  * If we have specified it via mount option, then
2824  * use the mount option value. If the value specified at mount time is
2825  * greater than the blocks per group use the super block value.
2826  * If the super block value is greater than blocks per group return 0.
2827  * Allocator needs it be less than blocks per group.
2828  *
2829  */
2830 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2831 {
2832 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2833 	unsigned long stripe_width =
2834 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2835 	int ret;
2836 
2837 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2838 		ret = sbi->s_stripe;
2839 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2840 		ret = stripe_width;
2841 	else if (stride && stride <= sbi->s_blocks_per_group)
2842 		ret = stride;
2843 	else
2844 		ret = 0;
2845 
2846 	/*
2847 	 * If the stripe width is 1, this makes no sense and
2848 	 * we set it to 0 to turn off stripe handling code.
2849 	 */
2850 	if (ret <= 1)
2851 		ret = 0;
2852 
2853 	return ret;
2854 }
2855 
2856 /*
2857  * Check whether this filesystem can be mounted based on
2858  * the features present and the RDONLY/RDWR mount requested.
2859  * Returns 1 if this filesystem can be mounted as requested,
2860  * 0 if it cannot be.
2861  */
2862 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2863 {
2864 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2865 		ext4_msg(sb, KERN_ERR,
2866 			"Couldn't mount because of "
2867 			"unsupported optional features (%x)",
2868 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2869 			~EXT4_FEATURE_INCOMPAT_SUPP));
2870 		return 0;
2871 	}
2872 
2873 	if (readonly)
2874 		return 1;
2875 
2876 	if (ext4_has_feature_readonly(sb)) {
2877 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2878 		sb->s_flags |= SB_RDONLY;
2879 		return 1;
2880 	}
2881 
2882 	/* Check that feature set is OK for a read-write mount */
2883 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2884 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2885 			 "unsupported optional features (%x)",
2886 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2887 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2888 		return 0;
2889 	}
2890 	/*
2891 	 * Large file size enabled file system can only be mounted
2892 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2893 	 */
2894 	if (ext4_has_feature_huge_file(sb)) {
2895 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2896 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2897 				 "cannot be mounted RDWR without "
2898 				 "CONFIG_LBDAF");
2899 			return 0;
2900 		}
2901 	}
2902 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2903 		ext4_msg(sb, KERN_ERR,
2904 			 "Can't support bigalloc feature without "
2905 			 "extents feature\n");
2906 		return 0;
2907 	}
2908 
2909 #ifndef CONFIG_QUOTA
2910 	if (ext4_has_feature_quota(sb) && !readonly) {
2911 		ext4_msg(sb, KERN_ERR,
2912 			 "Filesystem with quota feature cannot be mounted RDWR "
2913 			 "without CONFIG_QUOTA");
2914 		return 0;
2915 	}
2916 	if (ext4_has_feature_project(sb) && !readonly) {
2917 		ext4_msg(sb, KERN_ERR,
2918 			 "Filesystem with project quota feature cannot be mounted RDWR "
2919 			 "without CONFIG_QUOTA");
2920 		return 0;
2921 	}
2922 #endif  /* CONFIG_QUOTA */
2923 	return 1;
2924 }
2925 
2926 /*
2927  * This function is called once a day if we have errors logged
2928  * on the file system
2929  */
2930 static void print_daily_error_info(struct timer_list *t)
2931 {
2932 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2933 	struct super_block *sb = sbi->s_sb;
2934 	struct ext4_super_block *es = sbi->s_es;
2935 
2936 	if (es->s_error_count)
2937 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2938 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2939 			 le32_to_cpu(es->s_error_count));
2940 	if (es->s_first_error_time) {
2941 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2942 		       sb->s_id,
2943 		       ext4_get_tstamp(es, s_first_error_time),
2944 		       (int) sizeof(es->s_first_error_func),
2945 		       es->s_first_error_func,
2946 		       le32_to_cpu(es->s_first_error_line));
2947 		if (es->s_first_error_ino)
2948 			printk(KERN_CONT ": inode %u",
2949 			       le32_to_cpu(es->s_first_error_ino));
2950 		if (es->s_first_error_block)
2951 			printk(KERN_CONT ": block %llu", (unsigned long long)
2952 			       le64_to_cpu(es->s_first_error_block));
2953 		printk(KERN_CONT "\n");
2954 	}
2955 	if (es->s_last_error_time) {
2956 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
2957 		       sb->s_id,
2958 		       ext4_get_tstamp(es, s_last_error_time),
2959 		       (int) sizeof(es->s_last_error_func),
2960 		       es->s_last_error_func,
2961 		       le32_to_cpu(es->s_last_error_line));
2962 		if (es->s_last_error_ino)
2963 			printk(KERN_CONT ": inode %u",
2964 			       le32_to_cpu(es->s_last_error_ino));
2965 		if (es->s_last_error_block)
2966 			printk(KERN_CONT ": block %llu", (unsigned long long)
2967 			       le64_to_cpu(es->s_last_error_block));
2968 		printk(KERN_CONT "\n");
2969 	}
2970 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2971 }
2972 
2973 /* Find next suitable group and run ext4_init_inode_table */
2974 static int ext4_run_li_request(struct ext4_li_request *elr)
2975 {
2976 	struct ext4_group_desc *gdp = NULL;
2977 	ext4_group_t group, ngroups;
2978 	struct super_block *sb;
2979 	unsigned long timeout = 0;
2980 	int ret = 0;
2981 
2982 	sb = elr->lr_super;
2983 	ngroups = EXT4_SB(sb)->s_groups_count;
2984 
2985 	for (group = elr->lr_next_group; group < ngroups; group++) {
2986 		gdp = ext4_get_group_desc(sb, group, NULL);
2987 		if (!gdp) {
2988 			ret = 1;
2989 			break;
2990 		}
2991 
2992 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2993 			break;
2994 	}
2995 
2996 	if (group >= ngroups)
2997 		ret = 1;
2998 
2999 	if (!ret) {
3000 		timeout = jiffies;
3001 		ret = ext4_init_inode_table(sb, group,
3002 					    elr->lr_timeout ? 0 : 1);
3003 		if (elr->lr_timeout == 0) {
3004 			timeout = (jiffies - timeout) *
3005 				  elr->lr_sbi->s_li_wait_mult;
3006 			elr->lr_timeout = timeout;
3007 		}
3008 		elr->lr_next_sched = jiffies + elr->lr_timeout;
3009 		elr->lr_next_group = group + 1;
3010 	}
3011 	return ret;
3012 }
3013 
3014 /*
3015  * Remove lr_request from the list_request and free the
3016  * request structure. Should be called with li_list_mtx held
3017  */
3018 static void ext4_remove_li_request(struct ext4_li_request *elr)
3019 {
3020 	struct ext4_sb_info *sbi;
3021 
3022 	if (!elr)
3023 		return;
3024 
3025 	sbi = elr->lr_sbi;
3026 
3027 	list_del(&elr->lr_request);
3028 	sbi->s_li_request = NULL;
3029 	kfree(elr);
3030 }
3031 
3032 static void ext4_unregister_li_request(struct super_block *sb)
3033 {
3034 	mutex_lock(&ext4_li_mtx);
3035 	if (!ext4_li_info) {
3036 		mutex_unlock(&ext4_li_mtx);
3037 		return;
3038 	}
3039 
3040 	mutex_lock(&ext4_li_info->li_list_mtx);
3041 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3042 	mutex_unlock(&ext4_li_info->li_list_mtx);
3043 	mutex_unlock(&ext4_li_mtx);
3044 }
3045 
3046 static struct task_struct *ext4_lazyinit_task;
3047 
3048 /*
3049  * This is the function where ext4lazyinit thread lives. It walks
3050  * through the request list searching for next scheduled filesystem.
3051  * When such a fs is found, run the lazy initialization request
3052  * (ext4_rn_li_request) and keep track of the time spend in this
3053  * function. Based on that time we compute next schedule time of
3054  * the request. When walking through the list is complete, compute
3055  * next waking time and put itself into sleep.
3056  */
3057 static int ext4_lazyinit_thread(void *arg)
3058 {
3059 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3060 	struct list_head *pos, *n;
3061 	struct ext4_li_request *elr;
3062 	unsigned long next_wakeup, cur;
3063 
3064 	BUG_ON(NULL == eli);
3065 
3066 cont_thread:
3067 	while (true) {
3068 		next_wakeup = MAX_JIFFY_OFFSET;
3069 
3070 		mutex_lock(&eli->li_list_mtx);
3071 		if (list_empty(&eli->li_request_list)) {
3072 			mutex_unlock(&eli->li_list_mtx);
3073 			goto exit_thread;
3074 		}
3075 		list_for_each_safe(pos, n, &eli->li_request_list) {
3076 			int err = 0;
3077 			int progress = 0;
3078 			elr = list_entry(pos, struct ext4_li_request,
3079 					 lr_request);
3080 
3081 			if (time_before(jiffies, elr->lr_next_sched)) {
3082 				if (time_before(elr->lr_next_sched, next_wakeup))
3083 					next_wakeup = elr->lr_next_sched;
3084 				continue;
3085 			}
3086 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3087 				if (sb_start_write_trylock(elr->lr_super)) {
3088 					progress = 1;
3089 					/*
3090 					 * We hold sb->s_umount, sb can not
3091 					 * be removed from the list, it is
3092 					 * now safe to drop li_list_mtx
3093 					 */
3094 					mutex_unlock(&eli->li_list_mtx);
3095 					err = ext4_run_li_request(elr);
3096 					sb_end_write(elr->lr_super);
3097 					mutex_lock(&eli->li_list_mtx);
3098 					n = pos->next;
3099 				}
3100 				up_read((&elr->lr_super->s_umount));
3101 			}
3102 			/* error, remove the lazy_init job */
3103 			if (err) {
3104 				ext4_remove_li_request(elr);
3105 				continue;
3106 			}
3107 			if (!progress) {
3108 				elr->lr_next_sched = jiffies +
3109 					(prandom_u32()
3110 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3111 			}
3112 			if (time_before(elr->lr_next_sched, next_wakeup))
3113 				next_wakeup = elr->lr_next_sched;
3114 		}
3115 		mutex_unlock(&eli->li_list_mtx);
3116 
3117 		try_to_freeze();
3118 
3119 		cur = jiffies;
3120 		if ((time_after_eq(cur, next_wakeup)) ||
3121 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3122 			cond_resched();
3123 			continue;
3124 		}
3125 
3126 		schedule_timeout_interruptible(next_wakeup - cur);
3127 
3128 		if (kthread_should_stop()) {
3129 			ext4_clear_request_list();
3130 			goto exit_thread;
3131 		}
3132 	}
3133 
3134 exit_thread:
3135 	/*
3136 	 * It looks like the request list is empty, but we need
3137 	 * to check it under the li_list_mtx lock, to prevent any
3138 	 * additions into it, and of course we should lock ext4_li_mtx
3139 	 * to atomically free the list and ext4_li_info, because at
3140 	 * this point another ext4 filesystem could be registering
3141 	 * new one.
3142 	 */
3143 	mutex_lock(&ext4_li_mtx);
3144 	mutex_lock(&eli->li_list_mtx);
3145 	if (!list_empty(&eli->li_request_list)) {
3146 		mutex_unlock(&eli->li_list_mtx);
3147 		mutex_unlock(&ext4_li_mtx);
3148 		goto cont_thread;
3149 	}
3150 	mutex_unlock(&eli->li_list_mtx);
3151 	kfree(ext4_li_info);
3152 	ext4_li_info = NULL;
3153 	mutex_unlock(&ext4_li_mtx);
3154 
3155 	return 0;
3156 }
3157 
3158 static void ext4_clear_request_list(void)
3159 {
3160 	struct list_head *pos, *n;
3161 	struct ext4_li_request *elr;
3162 
3163 	mutex_lock(&ext4_li_info->li_list_mtx);
3164 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3165 		elr = list_entry(pos, struct ext4_li_request,
3166 				 lr_request);
3167 		ext4_remove_li_request(elr);
3168 	}
3169 	mutex_unlock(&ext4_li_info->li_list_mtx);
3170 }
3171 
3172 static int ext4_run_lazyinit_thread(void)
3173 {
3174 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3175 					 ext4_li_info, "ext4lazyinit");
3176 	if (IS_ERR(ext4_lazyinit_task)) {
3177 		int err = PTR_ERR(ext4_lazyinit_task);
3178 		ext4_clear_request_list();
3179 		kfree(ext4_li_info);
3180 		ext4_li_info = NULL;
3181 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3182 				 "initialization thread\n",
3183 				 err);
3184 		return err;
3185 	}
3186 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3187 	return 0;
3188 }
3189 
3190 /*
3191  * Check whether it make sense to run itable init. thread or not.
3192  * If there is at least one uninitialized inode table, return
3193  * corresponding group number, else the loop goes through all
3194  * groups and return total number of groups.
3195  */
3196 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3197 {
3198 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3199 	struct ext4_group_desc *gdp = NULL;
3200 
3201 	if (!ext4_has_group_desc_csum(sb))
3202 		return ngroups;
3203 
3204 	for (group = 0; group < ngroups; group++) {
3205 		gdp = ext4_get_group_desc(sb, group, NULL);
3206 		if (!gdp)
3207 			continue;
3208 
3209 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3210 			break;
3211 	}
3212 
3213 	return group;
3214 }
3215 
3216 static int ext4_li_info_new(void)
3217 {
3218 	struct ext4_lazy_init *eli = NULL;
3219 
3220 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3221 	if (!eli)
3222 		return -ENOMEM;
3223 
3224 	INIT_LIST_HEAD(&eli->li_request_list);
3225 	mutex_init(&eli->li_list_mtx);
3226 
3227 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3228 
3229 	ext4_li_info = eli;
3230 
3231 	return 0;
3232 }
3233 
3234 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3235 					    ext4_group_t start)
3236 {
3237 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3238 	struct ext4_li_request *elr;
3239 
3240 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3241 	if (!elr)
3242 		return NULL;
3243 
3244 	elr->lr_super = sb;
3245 	elr->lr_sbi = sbi;
3246 	elr->lr_next_group = start;
3247 
3248 	/*
3249 	 * Randomize first schedule time of the request to
3250 	 * spread the inode table initialization requests
3251 	 * better.
3252 	 */
3253 	elr->lr_next_sched = jiffies + (prandom_u32() %
3254 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3255 	return elr;
3256 }
3257 
3258 int ext4_register_li_request(struct super_block *sb,
3259 			     ext4_group_t first_not_zeroed)
3260 {
3261 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3262 	struct ext4_li_request *elr = NULL;
3263 	ext4_group_t ngroups = sbi->s_groups_count;
3264 	int ret = 0;
3265 
3266 	mutex_lock(&ext4_li_mtx);
3267 	if (sbi->s_li_request != NULL) {
3268 		/*
3269 		 * Reset timeout so it can be computed again, because
3270 		 * s_li_wait_mult might have changed.
3271 		 */
3272 		sbi->s_li_request->lr_timeout = 0;
3273 		goto out;
3274 	}
3275 
3276 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3277 	    !test_opt(sb, INIT_INODE_TABLE))
3278 		goto out;
3279 
3280 	elr = ext4_li_request_new(sb, first_not_zeroed);
3281 	if (!elr) {
3282 		ret = -ENOMEM;
3283 		goto out;
3284 	}
3285 
3286 	if (NULL == ext4_li_info) {
3287 		ret = ext4_li_info_new();
3288 		if (ret)
3289 			goto out;
3290 	}
3291 
3292 	mutex_lock(&ext4_li_info->li_list_mtx);
3293 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3294 	mutex_unlock(&ext4_li_info->li_list_mtx);
3295 
3296 	sbi->s_li_request = elr;
3297 	/*
3298 	 * set elr to NULL here since it has been inserted to
3299 	 * the request_list and the removal and free of it is
3300 	 * handled by ext4_clear_request_list from now on.
3301 	 */
3302 	elr = NULL;
3303 
3304 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3305 		ret = ext4_run_lazyinit_thread();
3306 		if (ret)
3307 			goto out;
3308 	}
3309 out:
3310 	mutex_unlock(&ext4_li_mtx);
3311 	if (ret)
3312 		kfree(elr);
3313 	return ret;
3314 }
3315 
3316 /*
3317  * We do not need to lock anything since this is called on
3318  * module unload.
3319  */
3320 static void ext4_destroy_lazyinit_thread(void)
3321 {
3322 	/*
3323 	 * If thread exited earlier
3324 	 * there's nothing to be done.
3325 	 */
3326 	if (!ext4_li_info || !ext4_lazyinit_task)
3327 		return;
3328 
3329 	kthread_stop(ext4_lazyinit_task);
3330 }
3331 
3332 static int set_journal_csum_feature_set(struct super_block *sb)
3333 {
3334 	int ret = 1;
3335 	int compat, incompat;
3336 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3337 
3338 	if (ext4_has_metadata_csum(sb)) {
3339 		/* journal checksum v3 */
3340 		compat = 0;
3341 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3342 	} else {
3343 		/* journal checksum v1 */
3344 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3345 		incompat = 0;
3346 	}
3347 
3348 	jbd2_journal_clear_features(sbi->s_journal,
3349 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3350 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3351 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3352 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3353 		ret = jbd2_journal_set_features(sbi->s_journal,
3354 				compat, 0,
3355 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3356 				incompat);
3357 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3358 		ret = jbd2_journal_set_features(sbi->s_journal,
3359 				compat, 0,
3360 				incompat);
3361 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3362 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3363 	} else {
3364 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3365 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3366 	}
3367 
3368 	return ret;
3369 }
3370 
3371 /*
3372  * Note: calculating the overhead so we can be compatible with
3373  * historical BSD practice is quite difficult in the face of
3374  * clusters/bigalloc.  This is because multiple metadata blocks from
3375  * different block group can end up in the same allocation cluster.
3376  * Calculating the exact overhead in the face of clustered allocation
3377  * requires either O(all block bitmaps) in memory or O(number of block
3378  * groups**2) in time.  We will still calculate the superblock for
3379  * older file systems --- and if we come across with a bigalloc file
3380  * system with zero in s_overhead_clusters the estimate will be close to
3381  * correct especially for very large cluster sizes --- but for newer
3382  * file systems, it's better to calculate this figure once at mkfs
3383  * time, and store it in the superblock.  If the superblock value is
3384  * present (even for non-bigalloc file systems), we will use it.
3385  */
3386 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3387 			  char *buf)
3388 {
3389 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3390 	struct ext4_group_desc	*gdp;
3391 	ext4_fsblk_t		first_block, last_block, b;
3392 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3393 	int			s, j, count = 0;
3394 
3395 	if (!ext4_has_feature_bigalloc(sb))
3396 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3397 			sbi->s_itb_per_group + 2);
3398 
3399 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3400 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3401 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3402 	for (i = 0; i < ngroups; i++) {
3403 		gdp = ext4_get_group_desc(sb, i, NULL);
3404 		b = ext4_block_bitmap(sb, gdp);
3405 		if (b >= first_block && b <= last_block) {
3406 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3407 			count++;
3408 		}
3409 		b = ext4_inode_bitmap(sb, gdp);
3410 		if (b >= first_block && b <= last_block) {
3411 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3412 			count++;
3413 		}
3414 		b = ext4_inode_table(sb, gdp);
3415 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3416 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3417 				int c = EXT4_B2C(sbi, b - first_block);
3418 				ext4_set_bit(c, buf);
3419 				count++;
3420 			}
3421 		if (i != grp)
3422 			continue;
3423 		s = 0;
3424 		if (ext4_bg_has_super(sb, grp)) {
3425 			ext4_set_bit(s++, buf);
3426 			count++;
3427 		}
3428 		j = ext4_bg_num_gdb(sb, grp);
3429 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3430 			ext4_error(sb, "Invalid number of block group "
3431 				   "descriptor blocks: %d", j);
3432 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3433 		}
3434 		count += j;
3435 		for (; j > 0; j--)
3436 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3437 	}
3438 	if (!count)
3439 		return 0;
3440 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3441 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3442 }
3443 
3444 /*
3445  * Compute the overhead and stash it in sbi->s_overhead
3446  */
3447 int ext4_calculate_overhead(struct super_block *sb)
3448 {
3449 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3450 	struct ext4_super_block *es = sbi->s_es;
3451 	struct inode *j_inode;
3452 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3453 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3454 	ext4_fsblk_t overhead = 0;
3455 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3456 
3457 	if (!buf)
3458 		return -ENOMEM;
3459 
3460 	/*
3461 	 * Compute the overhead (FS structures).  This is constant
3462 	 * for a given filesystem unless the number of block groups
3463 	 * changes so we cache the previous value until it does.
3464 	 */
3465 
3466 	/*
3467 	 * All of the blocks before first_data_block are overhead
3468 	 */
3469 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3470 
3471 	/*
3472 	 * Add the overhead found in each block group
3473 	 */
3474 	for (i = 0; i < ngroups; i++) {
3475 		int blks;
3476 
3477 		blks = count_overhead(sb, i, buf);
3478 		overhead += blks;
3479 		if (blks)
3480 			memset(buf, 0, PAGE_SIZE);
3481 		cond_resched();
3482 	}
3483 
3484 	/*
3485 	 * Add the internal journal blocks whether the journal has been
3486 	 * loaded or not
3487 	 */
3488 	if (sbi->s_journal && !sbi->journal_bdev)
3489 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3490 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3491 		j_inode = ext4_get_journal_inode(sb, j_inum);
3492 		if (j_inode) {
3493 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3494 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3495 			iput(j_inode);
3496 		} else {
3497 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3498 		}
3499 	}
3500 	sbi->s_overhead = overhead;
3501 	smp_wmb();
3502 	free_page((unsigned long) buf);
3503 	return 0;
3504 }
3505 
3506 static void ext4_set_resv_clusters(struct super_block *sb)
3507 {
3508 	ext4_fsblk_t resv_clusters;
3509 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3510 
3511 	/*
3512 	 * There's no need to reserve anything when we aren't using extents.
3513 	 * The space estimates are exact, there are no unwritten extents,
3514 	 * hole punching doesn't need new metadata... This is needed especially
3515 	 * to keep ext2/3 backward compatibility.
3516 	 */
3517 	if (!ext4_has_feature_extents(sb))
3518 		return;
3519 	/*
3520 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3521 	 * This should cover the situations where we can not afford to run
3522 	 * out of space like for example punch hole, or converting
3523 	 * unwritten extents in delalloc path. In most cases such
3524 	 * allocation would require 1, or 2 blocks, higher numbers are
3525 	 * very rare.
3526 	 */
3527 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3528 			 sbi->s_cluster_bits);
3529 
3530 	do_div(resv_clusters, 50);
3531 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3532 
3533 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3534 }
3535 
3536 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3537 {
3538 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3539 	char *orig_data = kstrdup(data, GFP_KERNEL);
3540 	struct buffer_head *bh;
3541 	struct ext4_super_block *es = NULL;
3542 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3543 	ext4_fsblk_t block;
3544 	ext4_fsblk_t sb_block = get_sb_block(&data);
3545 	ext4_fsblk_t logical_sb_block;
3546 	unsigned long offset = 0;
3547 	unsigned long journal_devnum = 0;
3548 	unsigned long def_mount_opts;
3549 	struct inode *root;
3550 	const char *descr;
3551 	int ret = -ENOMEM;
3552 	int blocksize, clustersize;
3553 	unsigned int db_count;
3554 	unsigned int i;
3555 	int needs_recovery, has_huge_files, has_bigalloc;
3556 	__u64 blocks_count;
3557 	int err = 0;
3558 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3559 	ext4_group_t first_not_zeroed;
3560 
3561 	if ((data && !orig_data) || !sbi)
3562 		goto out_free_base;
3563 
3564 	sbi->s_daxdev = dax_dev;
3565 	sbi->s_blockgroup_lock =
3566 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3567 	if (!sbi->s_blockgroup_lock)
3568 		goto out_free_base;
3569 
3570 	sb->s_fs_info = sbi;
3571 	sbi->s_sb = sb;
3572 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3573 	sbi->s_sb_block = sb_block;
3574 	if (sb->s_bdev->bd_part)
3575 		sbi->s_sectors_written_start =
3576 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3577 
3578 	/* Cleanup superblock name */
3579 	strreplace(sb->s_id, '/', '!');
3580 
3581 	/* -EINVAL is default */
3582 	ret = -EINVAL;
3583 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3584 	if (!blocksize) {
3585 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3586 		goto out_fail;
3587 	}
3588 
3589 	/*
3590 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3591 	 * block sizes.  We need to calculate the offset from buffer start.
3592 	 */
3593 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3594 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3595 		offset = do_div(logical_sb_block, blocksize);
3596 	} else {
3597 		logical_sb_block = sb_block;
3598 	}
3599 
3600 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3601 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3602 		goto out_fail;
3603 	}
3604 	/*
3605 	 * Note: s_es must be initialized as soon as possible because
3606 	 *       some ext4 macro-instructions depend on its value
3607 	 */
3608 	es = (struct ext4_super_block *) (bh->b_data + offset);
3609 	sbi->s_es = es;
3610 	sb->s_magic = le16_to_cpu(es->s_magic);
3611 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3612 		goto cantfind_ext4;
3613 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3614 
3615 	/* Warn if metadata_csum and gdt_csum are both set. */
3616 	if (ext4_has_feature_metadata_csum(sb) &&
3617 	    ext4_has_feature_gdt_csum(sb))
3618 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3619 			     "redundant flags; please run fsck.");
3620 
3621 	/* Check for a known checksum algorithm */
3622 	if (!ext4_verify_csum_type(sb, es)) {
3623 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3624 			 "unknown checksum algorithm.");
3625 		silent = 1;
3626 		goto cantfind_ext4;
3627 	}
3628 
3629 	/* Load the checksum driver */
3630 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3631 	if (IS_ERR(sbi->s_chksum_driver)) {
3632 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3633 		ret = PTR_ERR(sbi->s_chksum_driver);
3634 		sbi->s_chksum_driver = NULL;
3635 		goto failed_mount;
3636 	}
3637 
3638 	/* Check superblock checksum */
3639 	if (!ext4_superblock_csum_verify(sb, es)) {
3640 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3641 			 "invalid superblock checksum.  Run e2fsck?");
3642 		silent = 1;
3643 		ret = -EFSBADCRC;
3644 		goto cantfind_ext4;
3645 	}
3646 
3647 	/* Precompute checksum seed for all metadata */
3648 	if (ext4_has_feature_csum_seed(sb))
3649 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3650 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3651 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3652 					       sizeof(es->s_uuid));
3653 
3654 	/* Set defaults before we parse the mount options */
3655 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3656 	set_opt(sb, INIT_INODE_TABLE);
3657 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3658 		set_opt(sb, DEBUG);
3659 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3660 		set_opt(sb, GRPID);
3661 	if (def_mount_opts & EXT4_DEFM_UID16)
3662 		set_opt(sb, NO_UID32);
3663 	/* xattr user namespace & acls are now defaulted on */
3664 	set_opt(sb, XATTR_USER);
3665 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3666 	set_opt(sb, POSIX_ACL);
3667 #endif
3668 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3669 	if (ext4_has_metadata_csum(sb))
3670 		set_opt(sb, JOURNAL_CHECKSUM);
3671 
3672 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3673 		set_opt(sb, JOURNAL_DATA);
3674 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3675 		set_opt(sb, ORDERED_DATA);
3676 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3677 		set_opt(sb, WRITEBACK_DATA);
3678 
3679 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3680 		set_opt(sb, ERRORS_PANIC);
3681 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3682 		set_opt(sb, ERRORS_CONT);
3683 	else
3684 		set_opt(sb, ERRORS_RO);
3685 	/* block_validity enabled by default; disable with noblock_validity */
3686 	set_opt(sb, BLOCK_VALIDITY);
3687 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3688 		set_opt(sb, DISCARD);
3689 
3690 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3691 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3692 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3693 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3694 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3695 
3696 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3697 		set_opt(sb, BARRIER);
3698 
3699 	/*
3700 	 * enable delayed allocation by default
3701 	 * Use -o nodelalloc to turn it off
3702 	 */
3703 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3704 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3705 		set_opt(sb, DELALLOC);
3706 
3707 	/*
3708 	 * set default s_li_wait_mult for lazyinit, for the case there is
3709 	 * no mount option specified.
3710 	 */
3711 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3712 
3713 	if (sbi->s_es->s_mount_opts[0]) {
3714 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3715 					      sizeof(sbi->s_es->s_mount_opts),
3716 					      GFP_KERNEL);
3717 		if (!s_mount_opts)
3718 			goto failed_mount;
3719 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3720 				   &journal_ioprio, 0)) {
3721 			ext4_msg(sb, KERN_WARNING,
3722 				 "failed to parse options in superblock: %s",
3723 				 s_mount_opts);
3724 		}
3725 		kfree(s_mount_opts);
3726 	}
3727 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3728 	if (!parse_options((char *) data, sb, &journal_devnum,
3729 			   &journal_ioprio, 0))
3730 		goto failed_mount;
3731 
3732 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3733 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3734 			    "with data=journal disables delayed "
3735 			    "allocation and O_DIRECT support!\n");
3736 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3737 			ext4_msg(sb, KERN_ERR, "can't mount with "
3738 				 "both data=journal and delalloc");
3739 			goto failed_mount;
3740 		}
3741 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3742 			ext4_msg(sb, KERN_ERR, "can't mount with "
3743 				 "both data=journal and dioread_nolock");
3744 			goto failed_mount;
3745 		}
3746 		if (test_opt(sb, DAX)) {
3747 			ext4_msg(sb, KERN_ERR, "can't mount with "
3748 				 "both data=journal and dax");
3749 			goto failed_mount;
3750 		}
3751 		if (ext4_has_feature_encrypt(sb)) {
3752 			ext4_msg(sb, KERN_WARNING,
3753 				 "encrypted files will use data=ordered "
3754 				 "instead of data journaling mode");
3755 		}
3756 		if (test_opt(sb, DELALLOC))
3757 			clear_opt(sb, DELALLOC);
3758 	} else {
3759 		sb->s_iflags |= SB_I_CGROUPWB;
3760 	}
3761 
3762 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3763 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3764 
3765 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3766 	    (ext4_has_compat_features(sb) ||
3767 	     ext4_has_ro_compat_features(sb) ||
3768 	     ext4_has_incompat_features(sb)))
3769 		ext4_msg(sb, KERN_WARNING,
3770 		       "feature flags set on rev 0 fs, "
3771 		       "running e2fsck is recommended");
3772 
3773 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3774 		set_opt2(sb, HURD_COMPAT);
3775 		if (ext4_has_feature_64bit(sb)) {
3776 			ext4_msg(sb, KERN_ERR,
3777 				 "The Hurd can't support 64-bit file systems");
3778 			goto failed_mount;
3779 		}
3780 
3781 		/*
3782 		 * ea_inode feature uses l_i_version field which is not
3783 		 * available in HURD_COMPAT mode.
3784 		 */
3785 		if (ext4_has_feature_ea_inode(sb)) {
3786 			ext4_msg(sb, KERN_ERR,
3787 				 "ea_inode feature is not supported for Hurd");
3788 			goto failed_mount;
3789 		}
3790 	}
3791 
3792 	if (IS_EXT2_SB(sb)) {
3793 		if (ext2_feature_set_ok(sb))
3794 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3795 				 "using the ext4 subsystem");
3796 		else {
3797 			/*
3798 			 * If we're probing be silent, if this looks like
3799 			 * it's actually an ext[34] filesystem.
3800 			 */
3801 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3802 				goto failed_mount;
3803 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3804 				 "to feature incompatibilities");
3805 			goto failed_mount;
3806 		}
3807 	}
3808 
3809 	if (IS_EXT3_SB(sb)) {
3810 		if (ext3_feature_set_ok(sb))
3811 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3812 				 "using the ext4 subsystem");
3813 		else {
3814 			/*
3815 			 * If we're probing be silent, if this looks like
3816 			 * it's actually an ext4 filesystem.
3817 			 */
3818 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3819 				goto failed_mount;
3820 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3821 				 "to feature incompatibilities");
3822 			goto failed_mount;
3823 		}
3824 	}
3825 
3826 	/*
3827 	 * Check feature flags regardless of the revision level, since we
3828 	 * previously didn't change the revision level when setting the flags,
3829 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3830 	 */
3831 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3832 		goto failed_mount;
3833 
3834 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3835 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3836 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3837 		ext4_msg(sb, KERN_ERR,
3838 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3839 			 blocksize, le32_to_cpu(es->s_log_block_size));
3840 		goto failed_mount;
3841 	}
3842 	if (le32_to_cpu(es->s_log_block_size) >
3843 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3844 		ext4_msg(sb, KERN_ERR,
3845 			 "Invalid log block size: %u",
3846 			 le32_to_cpu(es->s_log_block_size));
3847 		goto failed_mount;
3848 	}
3849 	if (le32_to_cpu(es->s_log_cluster_size) >
3850 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3851 		ext4_msg(sb, KERN_ERR,
3852 			 "Invalid log cluster size: %u",
3853 			 le32_to_cpu(es->s_log_cluster_size));
3854 		goto failed_mount;
3855 	}
3856 
3857 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3858 		ext4_msg(sb, KERN_ERR,
3859 			 "Number of reserved GDT blocks insanely large: %d",
3860 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3861 		goto failed_mount;
3862 	}
3863 
3864 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3865 		if (ext4_has_feature_inline_data(sb)) {
3866 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3867 					" that may contain inline data");
3868 			goto failed_mount;
3869 		}
3870 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3871 			ext4_msg(sb, KERN_ERR,
3872 				"DAX unsupported by block device.");
3873 			goto failed_mount;
3874 		}
3875 	}
3876 
3877 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3878 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3879 			 es->s_encryption_level);
3880 		goto failed_mount;
3881 	}
3882 
3883 	if (sb->s_blocksize != blocksize) {
3884 		/* Validate the filesystem blocksize */
3885 		if (!sb_set_blocksize(sb, blocksize)) {
3886 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3887 					blocksize);
3888 			goto failed_mount;
3889 		}
3890 
3891 		brelse(bh);
3892 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3893 		offset = do_div(logical_sb_block, blocksize);
3894 		bh = sb_bread_unmovable(sb, logical_sb_block);
3895 		if (!bh) {
3896 			ext4_msg(sb, KERN_ERR,
3897 			       "Can't read superblock on 2nd try");
3898 			goto failed_mount;
3899 		}
3900 		es = (struct ext4_super_block *)(bh->b_data + offset);
3901 		sbi->s_es = es;
3902 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3903 			ext4_msg(sb, KERN_ERR,
3904 			       "Magic mismatch, very weird!");
3905 			goto failed_mount;
3906 		}
3907 	}
3908 
3909 	has_huge_files = ext4_has_feature_huge_file(sb);
3910 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3911 						      has_huge_files);
3912 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3913 
3914 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3915 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3916 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3917 	} else {
3918 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3919 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3920 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3921 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3922 				 sbi->s_first_ino);
3923 			goto failed_mount;
3924 		}
3925 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3926 		    (!is_power_of_2(sbi->s_inode_size)) ||
3927 		    (sbi->s_inode_size > blocksize)) {
3928 			ext4_msg(sb, KERN_ERR,
3929 			       "unsupported inode size: %d",
3930 			       sbi->s_inode_size);
3931 			goto failed_mount;
3932 		}
3933 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3934 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3935 	}
3936 
3937 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3938 	if (ext4_has_feature_64bit(sb)) {
3939 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3940 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3941 		    !is_power_of_2(sbi->s_desc_size)) {
3942 			ext4_msg(sb, KERN_ERR,
3943 			       "unsupported descriptor size %lu",
3944 			       sbi->s_desc_size);
3945 			goto failed_mount;
3946 		}
3947 	} else
3948 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3949 
3950 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3951 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3952 
3953 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3954 	if (sbi->s_inodes_per_block == 0)
3955 		goto cantfind_ext4;
3956 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3957 	    sbi->s_inodes_per_group > blocksize * 8) {
3958 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3959 			 sbi->s_blocks_per_group);
3960 		goto failed_mount;
3961 	}
3962 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3963 					sbi->s_inodes_per_block;
3964 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3965 	sbi->s_sbh = bh;
3966 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3967 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3968 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3969 
3970 	for (i = 0; i < 4; i++)
3971 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3972 	sbi->s_def_hash_version = es->s_def_hash_version;
3973 	if (ext4_has_feature_dir_index(sb)) {
3974 		i = le32_to_cpu(es->s_flags);
3975 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3976 			sbi->s_hash_unsigned = 3;
3977 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3978 #ifdef __CHAR_UNSIGNED__
3979 			if (!sb_rdonly(sb))
3980 				es->s_flags |=
3981 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3982 			sbi->s_hash_unsigned = 3;
3983 #else
3984 			if (!sb_rdonly(sb))
3985 				es->s_flags |=
3986 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3987 #endif
3988 		}
3989 	}
3990 
3991 	/* Handle clustersize */
3992 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3993 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3994 	if (has_bigalloc) {
3995 		if (clustersize < blocksize) {
3996 			ext4_msg(sb, KERN_ERR,
3997 				 "cluster size (%d) smaller than "
3998 				 "block size (%d)", clustersize, blocksize);
3999 			goto failed_mount;
4000 		}
4001 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
4002 			le32_to_cpu(es->s_log_block_size);
4003 		sbi->s_clusters_per_group =
4004 			le32_to_cpu(es->s_clusters_per_group);
4005 		if (sbi->s_clusters_per_group > blocksize * 8) {
4006 			ext4_msg(sb, KERN_ERR,
4007 				 "#clusters per group too big: %lu",
4008 				 sbi->s_clusters_per_group);
4009 			goto failed_mount;
4010 		}
4011 		if (sbi->s_blocks_per_group !=
4012 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4013 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4014 				 "clusters per group (%lu) inconsistent",
4015 				 sbi->s_blocks_per_group,
4016 				 sbi->s_clusters_per_group);
4017 			goto failed_mount;
4018 		}
4019 	} else {
4020 		if (clustersize != blocksize) {
4021 			ext4_msg(sb, KERN_ERR,
4022 				 "fragment/cluster size (%d) != "
4023 				 "block size (%d)", clustersize, blocksize);
4024 			goto failed_mount;
4025 		}
4026 		if (sbi->s_blocks_per_group > blocksize * 8) {
4027 			ext4_msg(sb, KERN_ERR,
4028 				 "#blocks per group too big: %lu",
4029 				 sbi->s_blocks_per_group);
4030 			goto failed_mount;
4031 		}
4032 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4033 		sbi->s_cluster_bits = 0;
4034 	}
4035 	sbi->s_cluster_ratio = clustersize / blocksize;
4036 
4037 	/* Do we have standard group size of clustersize * 8 blocks ? */
4038 	if (sbi->s_blocks_per_group == clustersize << 3)
4039 		set_opt2(sb, STD_GROUP_SIZE);
4040 
4041 	/*
4042 	 * Test whether we have more sectors than will fit in sector_t,
4043 	 * and whether the max offset is addressable by the page cache.
4044 	 */
4045 	err = generic_check_addressable(sb->s_blocksize_bits,
4046 					ext4_blocks_count(es));
4047 	if (err) {
4048 		ext4_msg(sb, KERN_ERR, "filesystem"
4049 			 " too large to mount safely on this system");
4050 		if (sizeof(sector_t) < 8)
4051 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
4052 		goto failed_mount;
4053 	}
4054 
4055 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4056 		goto cantfind_ext4;
4057 
4058 	/* check blocks count against device size */
4059 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4060 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4061 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4062 		       "exceeds size of device (%llu blocks)",
4063 		       ext4_blocks_count(es), blocks_count);
4064 		goto failed_mount;
4065 	}
4066 
4067 	/*
4068 	 * It makes no sense for the first data block to be beyond the end
4069 	 * of the filesystem.
4070 	 */
4071 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4072 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4073 			 "block %u is beyond end of filesystem (%llu)",
4074 			 le32_to_cpu(es->s_first_data_block),
4075 			 ext4_blocks_count(es));
4076 		goto failed_mount;
4077 	}
4078 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4079 	    (sbi->s_cluster_ratio == 1)) {
4080 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4081 			 "block is 0 with a 1k block and cluster size");
4082 		goto failed_mount;
4083 	}
4084 
4085 	blocks_count = (ext4_blocks_count(es) -
4086 			le32_to_cpu(es->s_first_data_block) +
4087 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4088 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4089 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4090 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4091 		       "(block count %llu, first data block %u, "
4092 		       "blocks per group %lu)", sbi->s_groups_count,
4093 		       ext4_blocks_count(es),
4094 		       le32_to_cpu(es->s_first_data_block),
4095 		       EXT4_BLOCKS_PER_GROUP(sb));
4096 		goto failed_mount;
4097 	}
4098 	sbi->s_groups_count = blocks_count;
4099 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4100 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4101 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4102 	    le32_to_cpu(es->s_inodes_count)) {
4103 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4104 			 le32_to_cpu(es->s_inodes_count),
4105 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4106 		ret = -EINVAL;
4107 		goto failed_mount;
4108 	}
4109 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4110 		   EXT4_DESC_PER_BLOCK(sb);
4111 	if (ext4_has_feature_meta_bg(sb)) {
4112 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4113 			ext4_msg(sb, KERN_WARNING,
4114 				 "first meta block group too large: %u "
4115 				 "(group descriptor block count %u)",
4116 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4117 			goto failed_mount;
4118 		}
4119 	}
4120 	sbi->s_group_desc = kvmalloc_array(db_count,
4121 					   sizeof(struct buffer_head *),
4122 					   GFP_KERNEL);
4123 	if (sbi->s_group_desc == NULL) {
4124 		ext4_msg(sb, KERN_ERR, "not enough memory");
4125 		ret = -ENOMEM;
4126 		goto failed_mount;
4127 	}
4128 
4129 	bgl_lock_init(sbi->s_blockgroup_lock);
4130 
4131 	/* Pre-read the descriptors into the buffer cache */
4132 	for (i = 0; i < db_count; i++) {
4133 		block = descriptor_loc(sb, logical_sb_block, i);
4134 		sb_breadahead(sb, block);
4135 	}
4136 
4137 	for (i = 0; i < db_count; i++) {
4138 		block = descriptor_loc(sb, logical_sb_block, i);
4139 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4140 		if (!sbi->s_group_desc[i]) {
4141 			ext4_msg(sb, KERN_ERR,
4142 			       "can't read group descriptor %d", i);
4143 			db_count = i;
4144 			goto failed_mount2;
4145 		}
4146 	}
4147 	sbi->s_gdb_count = db_count;
4148 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4149 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4150 		ret = -EFSCORRUPTED;
4151 		goto failed_mount2;
4152 	}
4153 
4154 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4155 
4156 	/* Register extent status tree shrinker */
4157 	if (ext4_es_register_shrinker(sbi))
4158 		goto failed_mount3;
4159 
4160 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4161 	sbi->s_extent_max_zeroout_kb = 32;
4162 
4163 	/*
4164 	 * set up enough so that it can read an inode
4165 	 */
4166 	sb->s_op = &ext4_sops;
4167 	sb->s_export_op = &ext4_export_ops;
4168 	sb->s_xattr = ext4_xattr_handlers;
4169 #ifdef CONFIG_FS_ENCRYPTION
4170 	sb->s_cop = &ext4_cryptops;
4171 #endif
4172 #ifdef CONFIG_QUOTA
4173 	sb->dq_op = &ext4_quota_operations;
4174 	if (ext4_has_feature_quota(sb))
4175 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4176 	else
4177 		sb->s_qcop = &ext4_qctl_operations;
4178 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4179 #endif
4180 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4181 
4182 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4183 	mutex_init(&sbi->s_orphan_lock);
4184 
4185 	sb->s_root = NULL;
4186 
4187 	needs_recovery = (es->s_last_orphan != 0 ||
4188 			  ext4_has_feature_journal_needs_recovery(sb));
4189 
4190 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4191 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4192 			goto failed_mount3a;
4193 
4194 	/*
4195 	 * The first inode we look at is the journal inode.  Don't try
4196 	 * root first: it may be modified in the journal!
4197 	 */
4198 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4199 		err = ext4_load_journal(sb, es, journal_devnum);
4200 		if (err)
4201 			goto failed_mount3a;
4202 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4203 		   ext4_has_feature_journal_needs_recovery(sb)) {
4204 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4205 		       "suppressed and not mounted read-only");
4206 		goto failed_mount_wq;
4207 	} else {
4208 		/* Nojournal mode, all journal mount options are illegal */
4209 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4210 			ext4_msg(sb, KERN_ERR, "can't mount with "
4211 				 "journal_checksum, fs mounted w/o journal");
4212 			goto failed_mount_wq;
4213 		}
4214 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4215 			ext4_msg(sb, KERN_ERR, "can't mount with "
4216 				 "journal_async_commit, fs mounted w/o journal");
4217 			goto failed_mount_wq;
4218 		}
4219 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4220 			ext4_msg(sb, KERN_ERR, "can't mount with "
4221 				 "commit=%lu, fs mounted w/o journal",
4222 				 sbi->s_commit_interval / HZ);
4223 			goto failed_mount_wq;
4224 		}
4225 		if (EXT4_MOUNT_DATA_FLAGS &
4226 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4227 			ext4_msg(sb, KERN_ERR, "can't mount with "
4228 				 "data=, fs mounted w/o journal");
4229 			goto failed_mount_wq;
4230 		}
4231 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4232 		clear_opt(sb, JOURNAL_CHECKSUM);
4233 		clear_opt(sb, DATA_FLAGS);
4234 		sbi->s_journal = NULL;
4235 		needs_recovery = 0;
4236 		goto no_journal;
4237 	}
4238 
4239 	if (ext4_has_feature_64bit(sb) &&
4240 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4241 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4242 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4243 		goto failed_mount_wq;
4244 	}
4245 
4246 	if (!set_journal_csum_feature_set(sb)) {
4247 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4248 			 "feature set");
4249 		goto failed_mount_wq;
4250 	}
4251 
4252 	/* We have now updated the journal if required, so we can
4253 	 * validate the data journaling mode. */
4254 	switch (test_opt(sb, DATA_FLAGS)) {
4255 	case 0:
4256 		/* No mode set, assume a default based on the journal
4257 		 * capabilities: ORDERED_DATA if the journal can
4258 		 * cope, else JOURNAL_DATA
4259 		 */
4260 		if (jbd2_journal_check_available_features
4261 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4262 			set_opt(sb, ORDERED_DATA);
4263 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4264 		} else {
4265 			set_opt(sb, JOURNAL_DATA);
4266 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4267 		}
4268 		break;
4269 
4270 	case EXT4_MOUNT_ORDERED_DATA:
4271 	case EXT4_MOUNT_WRITEBACK_DATA:
4272 		if (!jbd2_journal_check_available_features
4273 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4274 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4275 			       "requested data journaling mode");
4276 			goto failed_mount_wq;
4277 		}
4278 	default:
4279 		break;
4280 	}
4281 
4282 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4283 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4284 		ext4_msg(sb, KERN_ERR, "can't mount with "
4285 			"journal_async_commit in data=ordered mode");
4286 		goto failed_mount_wq;
4287 	}
4288 
4289 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4290 
4291 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4292 
4293 no_journal:
4294 	if (!test_opt(sb, NO_MBCACHE)) {
4295 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4296 		if (!sbi->s_ea_block_cache) {
4297 			ext4_msg(sb, KERN_ERR,
4298 				 "Failed to create ea_block_cache");
4299 			goto failed_mount_wq;
4300 		}
4301 
4302 		if (ext4_has_feature_ea_inode(sb)) {
4303 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4304 			if (!sbi->s_ea_inode_cache) {
4305 				ext4_msg(sb, KERN_ERR,
4306 					 "Failed to create ea_inode_cache");
4307 				goto failed_mount_wq;
4308 			}
4309 		}
4310 	}
4311 
4312 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4313 	    (blocksize != PAGE_SIZE)) {
4314 		ext4_msg(sb, KERN_ERR,
4315 			 "Unsupported blocksize for fs encryption");
4316 		goto failed_mount_wq;
4317 	}
4318 
4319 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4320 	    !ext4_has_feature_encrypt(sb)) {
4321 		ext4_set_feature_encrypt(sb);
4322 		ext4_commit_super(sb, 1);
4323 	}
4324 
4325 	/*
4326 	 * Get the # of file system overhead blocks from the
4327 	 * superblock if present.
4328 	 */
4329 	if (es->s_overhead_clusters)
4330 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4331 	else {
4332 		err = ext4_calculate_overhead(sb);
4333 		if (err)
4334 			goto failed_mount_wq;
4335 	}
4336 
4337 	/*
4338 	 * The maximum number of concurrent works can be high and
4339 	 * concurrency isn't really necessary.  Limit it to 1.
4340 	 */
4341 	EXT4_SB(sb)->rsv_conversion_wq =
4342 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4343 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4344 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4345 		ret = -ENOMEM;
4346 		goto failed_mount4;
4347 	}
4348 
4349 	/*
4350 	 * The jbd2_journal_load will have done any necessary log recovery,
4351 	 * so we can safely mount the rest of the filesystem now.
4352 	 */
4353 
4354 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4355 	if (IS_ERR(root)) {
4356 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4357 		ret = PTR_ERR(root);
4358 		root = NULL;
4359 		goto failed_mount4;
4360 	}
4361 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4362 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4363 		iput(root);
4364 		goto failed_mount4;
4365 	}
4366 	sb->s_root = d_make_root(root);
4367 	if (!sb->s_root) {
4368 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4369 		ret = -ENOMEM;
4370 		goto failed_mount4;
4371 	}
4372 
4373 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4374 	if (ret == -EROFS) {
4375 		sb->s_flags |= SB_RDONLY;
4376 		ret = 0;
4377 	} else if (ret)
4378 		goto failed_mount4a;
4379 
4380 	/* determine the minimum size of new large inodes, if present */
4381 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4382 	    sbi->s_want_extra_isize == 0) {
4383 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4384 						     EXT4_GOOD_OLD_INODE_SIZE;
4385 		if (ext4_has_feature_extra_isize(sb)) {
4386 			if (sbi->s_want_extra_isize <
4387 			    le16_to_cpu(es->s_want_extra_isize))
4388 				sbi->s_want_extra_isize =
4389 					le16_to_cpu(es->s_want_extra_isize);
4390 			if (sbi->s_want_extra_isize <
4391 			    le16_to_cpu(es->s_min_extra_isize))
4392 				sbi->s_want_extra_isize =
4393 					le16_to_cpu(es->s_min_extra_isize);
4394 		}
4395 	}
4396 	/* Check if enough inode space is available */
4397 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4398 							sbi->s_inode_size) {
4399 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4400 						       EXT4_GOOD_OLD_INODE_SIZE;
4401 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4402 			 "available");
4403 	}
4404 
4405 	ext4_set_resv_clusters(sb);
4406 
4407 	err = ext4_setup_system_zone(sb);
4408 	if (err) {
4409 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4410 			 "zone (%d)", err);
4411 		goto failed_mount4a;
4412 	}
4413 
4414 	ext4_ext_init(sb);
4415 	err = ext4_mb_init(sb);
4416 	if (err) {
4417 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4418 			 err);
4419 		goto failed_mount5;
4420 	}
4421 
4422 	block = ext4_count_free_clusters(sb);
4423 	ext4_free_blocks_count_set(sbi->s_es,
4424 				   EXT4_C2B(sbi, block));
4425 	ext4_superblock_csum_set(sb);
4426 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4427 				  GFP_KERNEL);
4428 	if (!err) {
4429 		unsigned long freei = ext4_count_free_inodes(sb);
4430 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4431 		ext4_superblock_csum_set(sb);
4432 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4433 					  GFP_KERNEL);
4434 	}
4435 	if (!err)
4436 		err = percpu_counter_init(&sbi->s_dirs_counter,
4437 					  ext4_count_dirs(sb), GFP_KERNEL);
4438 	if (!err)
4439 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4440 					  GFP_KERNEL);
4441 	if (!err)
4442 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4443 
4444 	if (err) {
4445 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4446 		goto failed_mount6;
4447 	}
4448 
4449 	if (ext4_has_feature_flex_bg(sb))
4450 		if (!ext4_fill_flex_info(sb)) {
4451 			ext4_msg(sb, KERN_ERR,
4452 			       "unable to initialize "
4453 			       "flex_bg meta info!");
4454 			goto failed_mount6;
4455 		}
4456 
4457 	err = ext4_register_li_request(sb, first_not_zeroed);
4458 	if (err)
4459 		goto failed_mount6;
4460 
4461 	err = ext4_register_sysfs(sb);
4462 	if (err)
4463 		goto failed_mount7;
4464 
4465 #ifdef CONFIG_QUOTA
4466 	/* Enable quota usage during mount. */
4467 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4468 		err = ext4_enable_quotas(sb);
4469 		if (err)
4470 			goto failed_mount8;
4471 	}
4472 #endif  /* CONFIG_QUOTA */
4473 
4474 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4475 	ext4_orphan_cleanup(sb, es);
4476 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4477 	if (needs_recovery) {
4478 		ext4_msg(sb, KERN_INFO, "recovery complete");
4479 		ext4_mark_recovery_complete(sb, es);
4480 	}
4481 	if (EXT4_SB(sb)->s_journal) {
4482 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4483 			descr = " journalled data mode";
4484 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4485 			descr = " ordered data mode";
4486 		else
4487 			descr = " writeback data mode";
4488 	} else
4489 		descr = "out journal";
4490 
4491 	if (test_opt(sb, DISCARD)) {
4492 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4493 		if (!blk_queue_discard(q))
4494 			ext4_msg(sb, KERN_WARNING,
4495 				 "mounting with \"discard\" option, but "
4496 				 "the device does not support discard");
4497 	}
4498 
4499 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4500 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4501 			 "Opts: %.*s%s%s", descr,
4502 			 (int) sizeof(sbi->s_es->s_mount_opts),
4503 			 sbi->s_es->s_mount_opts,
4504 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4505 
4506 	if (es->s_error_count)
4507 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4508 
4509 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4510 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4511 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4512 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4513 
4514 	kfree(orig_data);
4515 	return 0;
4516 
4517 cantfind_ext4:
4518 	if (!silent)
4519 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4520 	goto failed_mount;
4521 
4522 #ifdef CONFIG_QUOTA
4523 failed_mount8:
4524 	ext4_unregister_sysfs(sb);
4525 #endif
4526 failed_mount7:
4527 	ext4_unregister_li_request(sb);
4528 failed_mount6:
4529 	ext4_mb_release(sb);
4530 	if (sbi->s_flex_groups)
4531 		kvfree(sbi->s_flex_groups);
4532 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4533 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4534 	percpu_counter_destroy(&sbi->s_dirs_counter);
4535 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4536 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4537 failed_mount5:
4538 	ext4_ext_release(sb);
4539 	ext4_release_system_zone(sb);
4540 failed_mount4a:
4541 	dput(sb->s_root);
4542 	sb->s_root = NULL;
4543 failed_mount4:
4544 	ext4_msg(sb, KERN_ERR, "mount failed");
4545 	if (EXT4_SB(sb)->rsv_conversion_wq)
4546 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4547 failed_mount_wq:
4548 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4549 	sbi->s_ea_inode_cache = NULL;
4550 
4551 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4552 	sbi->s_ea_block_cache = NULL;
4553 
4554 	if (sbi->s_journal) {
4555 		jbd2_journal_destroy(sbi->s_journal);
4556 		sbi->s_journal = NULL;
4557 	}
4558 failed_mount3a:
4559 	ext4_es_unregister_shrinker(sbi);
4560 failed_mount3:
4561 	del_timer_sync(&sbi->s_err_report);
4562 	if (sbi->s_mmp_tsk)
4563 		kthread_stop(sbi->s_mmp_tsk);
4564 failed_mount2:
4565 	for (i = 0; i < db_count; i++)
4566 		brelse(sbi->s_group_desc[i]);
4567 	kvfree(sbi->s_group_desc);
4568 failed_mount:
4569 	if (sbi->s_chksum_driver)
4570 		crypto_free_shash(sbi->s_chksum_driver);
4571 #ifdef CONFIG_QUOTA
4572 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4573 		kfree(sbi->s_qf_names[i]);
4574 #endif
4575 	ext4_blkdev_remove(sbi);
4576 	brelse(bh);
4577 out_fail:
4578 	sb->s_fs_info = NULL;
4579 	kfree(sbi->s_blockgroup_lock);
4580 out_free_base:
4581 	kfree(sbi);
4582 	kfree(orig_data);
4583 	fs_put_dax(dax_dev);
4584 	return err ? err : ret;
4585 }
4586 
4587 /*
4588  * Setup any per-fs journal parameters now.  We'll do this both on
4589  * initial mount, once the journal has been initialised but before we've
4590  * done any recovery; and again on any subsequent remount.
4591  */
4592 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4593 {
4594 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4595 
4596 	journal->j_commit_interval = sbi->s_commit_interval;
4597 	journal->j_min_batch_time = sbi->s_min_batch_time;
4598 	journal->j_max_batch_time = sbi->s_max_batch_time;
4599 
4600 	write_lock(&journal->j_state_lock);
4601 	if (test_opt(sb, BARRIER))
4602 		journal->j_flags |= JBD2_BARRIER;
4603 	else
4604 		journal->j_flags &= ~JBD2_BARRIER;
4605 	if (test_opt(sb, DATA_ERR_ABORT))
4606 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4607 	else
4608 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4609 	write_unlock(&journal->j_state_lock);
4610 }
4611 
4612 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4613 					     unsigned int journal_inum)
4614 {
4615 	struct inode *journal_inode;
4616 
4617 	/*
4618 	 * Test for the existence of a valid inode on disk.  Bad things
4619 	 * happen if we iget() an unused inode, as the subsequent iput()
4620 	 * will try to delete it.
4621 	 */
4622 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4623 	if (IS_ERR(journal_inode)) {
4624 		ext4_msg(sb, KERN_ERR, "no journal found");
4625 		return NULL;
4626 	}
4627 	if (!journal_inode->i_nlink) {
4628 		make_bad_inode(journal_inode);
4629 		iput(journal_inode);
4630 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4631 		return NULL;
4632 	}
4633 
4634 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4635 		  journal_inode, journal_inode->i_size);
4636 	if (!S_ISREG(journal_inode->i_mode)) {
4637 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4638 		iput(journal_inode);
4639 		return NULL;
4640 	}
4641 	return journal_inode;
4642 }
4643 
4644 static journal_t *ext4_get_journal(struct super_block *sb,
4645 				   unsigned int journal_inum)
4646 {
4647 	struct inode *journal_inode;
4648 	journal_t *journal;
4649 
4650 	BUG_ON(!ext4_has_feature_journal(sb));
4651 
4652 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4653 	if (!journal_inode)
4654 		return NULL;
4655 
4656 	journal = jbd2_journal_init_inode(journal_inode);
4657 	if (!journal) {
4658 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4659 		iput(journal_inode);
4660 		return NULL;
4661 	}
4662 	journal->j_private = sb;
4663 	ext4_init_journal_params(sb, journal);
4664 	return journal;
4665 }
4666 
4667 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4668 				       dev_t j_dev)
4669 {
4670 	struct buffer_head *bh;
4671 	journal_t *journal;
4672 	ext4_fsblk_t start;
4673 	ext4_fsblk_t len;
4674 	int hblock, blocksize;
4675 	ext4_fsblk_t sb_block;
4676 	unsigned long offset;
4677 	struct ext4_super_block *es;
4678 	struct block_device *bdev;
4679 
4680 	BUG_ON(!ext4_has_feature_journal(sb));
4681 
4682 	bdev = ext4_blkdev_get(j_dev, sb);
4683 	if (bdev == NULL)
4684 		return NULL;
4685 
4686 	blocksize = sb->s_blocksize;
4687 	hblock = bdev_logical_block_size(bdev);
4688 	if (blocksize < hblock) {
4689 		ext4_msg(sb, KERN_ERR,
4690 			"blocksize too small for journal device");
4691 		goto out_bdev;
4692 	}
4693 
4694 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4695 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4696 	set_blocksize(bdev, blocksize);
4697 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4698 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4699 		       "external journal");
4700 		goto out_bdev;
4701 	}
4702 
4703 	es = (struct ext4_super_block *) (bh->b_data + offset);
4704 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4705 	    !(le32_to_cpu(es->s_feature_incompat) &
4706 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4707 		ext4_msg(sb, KERN_ERR, "external journal has "
4708 					"bad superblock");
4709 		brelse(bh);
4710 		goto out_bdev;
4711 	}
4712 
4713 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4714 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4715 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4716 		ext4_msg(sb, KERN_ERR, "external journal has "
4717 				       "corrupt superblock");
4718 		brelse(bh);
4719 		goto out_bdev;
4720 	}
4721 
4722 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4723 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4724 		brelse(bh);
4725 		goto out_bdev;
4726 	}
4727 
4728 	len = ext4_blocks_count(es);
4729 	start = sb_block + 1;
4730 	brelse(bh);	/* we're done with the superblock */
4731 
4732 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4733 					start, len, blocksize);
4734 	if (!journal) {
4735 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4736 		goto out_bdev;
4737 	}
4738 	journal->j_private = sb;
4739 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4740 	wait_on_buffer(journal->j_sb_buffer);
4741 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4742 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4743 		goto out_journal;
4744 	}
4745 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4746 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4747 					"user (unsupported) - %d",
4748 			be32_to_cpu(journal->j_superblock->s_nr_users));
4749 		goto out_journal;
4750 	}
4751 	EXT4_SB(sb)->journal_bdev = bdev;
4752 	ext4_init_journal_params(sb, journal);
4753 	return journal;
4754 
4755 out_journal:
4756 	jbd2_journal_destroy(journal);
4757 out_bdev:
4758 	ext4_blkdev_put(bdev);
4759 	return NULL;
4760 }
4761 
4762 static int ext4_load_journal(struct super_block *sb,
4763 			     struct ext4_super_block *es,
4764 			     unsigned long journal_devnum)
4765 {
4766 	journal_t *journal;
4767 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4768 	dev_t journal_dev;
4769 	int err = 0;
4770 	int really_read_only;
4771 
4772 	BUG_ON(!ext4_has_feature_journal(sb));
4773 
4774 	if (journal_devnum &&
4775 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4776 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4777 			"numbers have changed");
4778 		journal_dev = new_decode_dev(journal_devnum);
4779 	} else
4780 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4781 
4782 	really_read_only = bdev_read_only(sb->s_bdev);
4783 
4784 	/*
4785 	 * Are we loading a blank journal or performing recovery after a
4786 	 * crash?  For recovery, we need to check in advance whether we
4787 	 * can get read-write access to the device.
4788 	 */
4789 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4790 		if (sb_rdonly(sb)) {
4791 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4792 					"required on readonly filesystem");
4793 			if (really_read_only) {
4794 				ext4_msg(sb, KERN_ERR, "write access "
4795 					"unavailable, cannot proceed "
4796 					"(try mounting with noload)");
4797 				return -EROFS;
4798 			}
4799 			ext4_msg(sb, KERN_INFO, "write access will "
4800 			       "be enabled during recovery");
4801 		}
4802 	}
4803 
4804 	if (journal_inum && journal_dev) {
4805 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4806 		       "and inode journals!");
4807 		return -EINVAL;
4808 	}
4809 
4810 	if (journal_inum) {
4811 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4812 			return -EINVAL;
4813 	} else {
4814 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4815 			return -EINVAL;
4816 	}
4817 
4818 	if (!(journal->j_flags & JBD2_BARRIER))
4819 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4820 
4821 	if (!ext4_has_feature_journal_needs_recovery(sb))
4822 		err = jbd2_journal_wipe(journal, !really_read_only);
4823 	if (!err) {
4824 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4825 		if (save)
4826 			memcpy(save, ((char *) es) +
4827 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4828 		err = jbd2_journal_load(journal);
4829 		if (save)
4830 			memcpy(((char *) es) + EXT4_S_ERR_START,
4831 			       save, EXT4_S_ERR_LEN);
4832 		kfree(save);
4833 	}
4834 
4835 	if (err) {
4836 		ext4_msg(sb, KERN_ERR, "error loading journal");
4837 		jbd2_journal_destroy(journal);
4838 		return err;
4839 	}
4840 
4841 	EXT4_SB(sb)->s_journal = journal;
4842 	ext4_clear_journal_err(sb, es);
4843 
4844 	if (!really_read_only && journal_devnum &&
4845 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4846 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4847 
4848 		/* Make sure we flush the recovery flag to disk. */
4849 		ext4_commit_super(sb, 1);
4850 	}
4851 
4852 	return 0;
4853 }
4854 
4855 static int ext4_commit_super(struct super_block *sb, int sync)
4856 {
4857 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4858 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4859 	int error = 0;
4860 
4861 	if (!sbh || block_device_ejected(sb))
4862 		return error;
4863 
4864 	/*
4865 	 * The superblock bh should be mapped, but it might not be if the
4866 	 * device was hot-removed. Not much we can do but fail the I/O.
4867 	 */
4868 	if (!buffer_mapped(sbh))
4869 		return error;
4870 
4871 	/*
4872 	 * If the file system is mounted read-only, don't update the
4873 	 * superblock write time.  This avoids updating the superblock
4874 	 * write time when we are mounting the root file system
4875 	 * read/only but we need to replay the journal; at that point,
4876 	 * for people who are east of GMT and who make their clock
4877 	 * tick in localtime for Windows bug-for-bug compatibility,
4878 	 * the clock is set in the future, and this will cause e2fsck
4879 	 * to complain and force a full file system check.
4880 	 */
4881 	if (!(sb->s_flags & SB_RDONLY))
4882 		ext4_update_tstamp(es, s_wtime);
4883 	if (sb->s_bdev->bd_part)
4884 		es->s_kbytes_written =
4885 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4886 			    ((part_stat_read(sb->s_bdev->bd_part,
4887 					     sectors[STAT_WRITE]) -
4888 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4889 	else
4890 		es->s_kbytes_written =
4891 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4892 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4893 		ext4_free_blocks_count_set(es,
4894 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4895 				&EXT4_SB(sb)->s_freeclusters_counter)));
4896 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4897 		es->s_free_inodes_count =
4898 			cpu_to_le32(percpu_counter_sum_positive(
4899 				&EXT4_SB(sb)->s_freeinodes_counter));
4900 	BUFFER_TRACE(sbh, "marking dirty");
4901 	ext4_superblock_csum_set(sb);
4902 	if (sync)
4903 		lock_buffer(sbh);
4904 	if (buffer_write_io_error(sbh) || !buffer_uptodate(sbh)) {
4905 		/*
4906 		 * Oh, dear.  A previous attempt to write the
4907 		 * superblock failed.  This could happen because the
4908 		 * USB device was yanked out.  Or it could happen to
4909 		 * be a transient write error and maybe the block will
4910 		 * be remapped.  Nothing we can do but to retry the
4911 		 * write and hope for the best.
4912 		 */
4913 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4914 		       "superblock detected");
4915 		clear_buffer_write_io_error(sbh);
4916 		set_buffer_uptodate(sbh);
4917 	}
4918 	mark_buffer_dirty(sbh);
4919 	if (sync) {
4920 		unlock_buffer(sbh);
4921 		error = __sync_dirty_buffer(sbh,
4922 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4923 		if (buffer_write_io_error(sbh)) {
4924 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4925 			       "superblock");
4926 			clear_buffer_write_io_error(sbh);
4927 			set_buffer_uptodate(sbh);
4928 		}
4929 	}
4930 	return error;
4931 }
4932 
4933 /*
4934  * Have we just finished recovery?  If so, and if we are mounting (or
4935  * remounting) the filesystem readonly, then we will end up with a
4936  * consistent fs on disk.  Record that fact.
4937  */
4938 static void ext4_mark_recovery_complete(struct super_block *sb,
4939 					struct ext4_super_block *es)
4940 {
4941 	journal_t *journal = EXT4_SB(sb)->s_journal;
4942 
4943 	if (!ext4_has_feature_journal(sb)) {
4944 		BUG_ON(journal != NULL);
4945 		return;
4946 	}
4947 	jbd2_journal_lock_updates(journal);
4948 	if (jbd2_journal_flush(journal) < 0)
4949 		goto out;
4950 
4951 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4952 		ext4_clear_feature_journal_needs_recovery(sb);
4953 		ext4_commit_super(sb, 1);
4954 	}
4955 
4956 out:
4957 	jbd2_journal_unlock_updates(journal);
4958 }
4959 
4960 /*
4961  * If we are mounting (or read-write remounting) a filesystem whose journal
4962  * has recorded an error from a previous lifetime, move that error to the
4963  * main filesystem now.
4964  */
4965 static void ext4_clear_journal_err(struct super_block *sb,
4966 				   struct ext4_super_block *es)
4967 {
4968 	journal_t *journal;
4969 	int j_errno;
4970 	const char *errstr;
4971 
4972 	BUG_ON(!ext4_has_feature_journal(sb));
4973 
4974 	journal = EXT4_SB(sb)->s_journal;
4975 
4976 	/*
4977 	 * Now check for any error status which may have been recorded in the
4978 	 * journal by a prior ext4_error() or ext4_abort()
4979 	 */
4980 
4981 	j_errno = jbd2_journal_errno(journal);
4982 	if (j_errno) {
4983 		char nbuf[16];
4984 
4985 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4986 		ext4_warning(sb, "Filesystem error recorded "
4987 			     "from previous mount: %s", errstr);
4988 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4989 
4990 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4991 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4992 		ext4_commit_super(sb, 1);
4993 
4994 		jbd2_journal_clear_err(journal);
4995 		jbd2_journal_update_sb_errno(journal);
4996 	}
4997 }
4998 
4999 /*
5000  * Force the running and committing transactions to commit,
5001  * and wait on the commit.
5002  */
5003 int ext4_force_commit(struct super_block *sb)
5004 {
5005 	journal_t *journal;
5006 
5007 	if (sb_rdonly(sb))
5008 		return 0;
5009 
5010 	journal = EXT4_SB(sb)->s_journal;
5011 	return ext4_journal_force_commit(journal);
5012 }
5013 
5014 static int ext4_sync_fs(struct super_block *sb, int wait)
5015 {
5016 	int ret = 0;
5017 	tid_t target;
5018 	bool needs_barrier = false;
5019 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5020 
5021 	if (unlikely(ext4_forced_shutdown(sbi)))
5022 		return 0;
5023 
5024 	trace_ext4_sync_fs(sb, wait);
5025 	flush_workqueue(sbi->rsv_conversion_wq);
5026 	/*
5027 	 * Writeback quota in non-journalled quota case - journalled quota has
5028 	 * no dirty dquots
5029 	 */
5030 	dquot_writeback_dquots(sb, -1);
5031 	/*
5032 	 * Data writeback is possible w/o journal transaction, so barrier must
5033 	 * being sent at the end of the function. But we can skip it if
5034 	 * transaction_commit will do it for us.
5035 	 */
5036 	if (sbi->s_journal) {
5037 		target = jbd2_get_latest_transaction(sbi->s_journal);
5038 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5039 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5040 			needs_barrier = true;
5041 
5042 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5043 			if (wait)
5044 				ret = jbd2_log_wait_commit(sbi->s_journal,
5045 							   target);
5046 		}
5047 	} else if (wait && test_opt(sb, BARRIER))
5048 		needs_barrier = true;
5049 	if (needs_barrier) {
5050 		int err;
5051 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5052 		if (!ret)
5053 			ret = err;
5054 	}
5055 
5056 	return ret;
5057 }
5058 
5059 /*
5060  * LVM calls this function before a (read-only) snapshot is created.  This
5061  * gives us a chance to flush the journal completely and mark the fs clean.
5062  *
5063  * Note that only this function cannot bring a filesystem to be in a clean
5064  * state independently. It relies on upper layer to stop all data & metadata
5065  * modifications.
5066  */
5067 static int ext4_freeze(struct super_block *sb)
5068 {
5069 	int error = 0;
5070 	journal_t *journal;
5071 
5072 	if (sb_rdonly(sb))
5073 		return 0;
5074 
5075 	journal = EXT4_SB(sb)->s_journal;
5076 
5077 	if (journal) {
5078 		/* Now we set up the journal barrier. */
5079 		jbd2_journal_lock_updates(journal);
5080 
5081 		/*
5082 		 * Don't clear the needs_recovery flag if we failed to
5083 		 * flush the journal.
5084 		 */
5085 		error = jbd2_journal_flush(journal);
5086 		if (error < 0)
5087 			goto out;
5088 
5089 		/* Journal blocked and flushed, clear needs_recovery flag. */
5090 		ext4_clear_feature_journal_needs_recovery(sb);
5091 	}
5092 
5093 	error = ext4_commit_super(sb, 1);
5094 out:
5095 	if (journal)
5096 		/* we rely on upper layer to stop further updates */
5097 		jbd2_journal_unlock_updates(journal);
5098 	return error;
5099 }
5100 
5101 /*
5102  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5103  * flag here, even though the filesystem is not technically dirty yet.
5104  */
5105 static int ext4_unfreeze(struct super_block *sb)
5106 {
5107 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5108 		return 0;
5109 
5110 	if (EXT4_SB(sb)->s_journal) {
5111 		/* Reset the needs_recovery flag before the fs is unlocked. */
5112 		ext4_set_feature_journal_needs_recovery(sb);
5113 	}
5114 
5115 	ext4_commit_super(sb, 1);
5116 	return 0;
5117 }
5118 
5119 /*
5120  * Structure to save mount options for ext4_remount's benefit
5121  */
5122 struct ext4_mount_options {
5123 	unsigned long s_mount_opt;
5124 	unsigned long s_mount_opt2;
5125 	kuid_t s_resuid;
5126 	kgid_t s_resgid;
5127 	unsigned long s_commit_interval;
5128 	u32 s_min_batch_time, s_max_batch_time;
5129 #ifdef CONFIG_QUOTA
5130 	int s_jquota_fmt;
5131 	char *s_qf_names[EXT4_MAXQUOTAS];
5132 #endif
5133 };
5134 
5135 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5136 {
5137 	struct ext4_super_block *es;
5138 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5139 	unsigned long old_sb_flags;
5140 	struct ext4_mount_options old_opts;
5141 	int enable_quota = 0;
5142 	ext4_group_t g;
5143 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5144 	int err = 0;
5145 #ifdef CONFIG_QUOTA
5146 	int i, j;
5147 	char *to_free[EXT4_MAXQUOTAS];
5148 #endif
5149 	char *orig_data = kstrdup(data, GFP_KERNEL);
5150 
5151 	if (data && !orig_data)
5152 		return -ENOMEM;
5153 
5154 	/* Store the original options */
5155 	old_sb_flags = sb->s_flags;
5156 	old_opts.s_mount_opt = sbi->s_mount_opt;
5157 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5158 	old_opts.s_resuid = sbi->s_resuid;
5159 	old_opts.s_resgid = sbi->s_resgid;
5160 	old_opts.s_commit_interval = sbi->s_commit_interval;
5161 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5162 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5163 #ifdef CONFIG_QUOTA
5164 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5165 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5166 		if (sbi->s_qf_names[i]) {
5167 			char *qf_name = get_qf_name(sb, sbi, i);
5168 
5169 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5170 			if (!old_opts.s_qf_names[i]) {
5171 				for (j = 0; j < i; j++)
5172 					kfree(old_opts.s_qf_names[j]);
5173 				kfree(orig_data);
5174 				return -ENOMEM;
5175 			}
5176 		} else
5177 			old_opts.s_qf_names[i] = NULL;
5178 #endif
5179 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5180 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5181 
5182 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5183 		err = -EINVAL;
5184 		goto restore_opts;
5185 	}
5186 
5187 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5188 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5189 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5190 			 "during remount not supported; ignoring");
5191 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5192 	}
5193 
5194 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5195 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5196 			ext4_msg(sb, KERN_ERR, "can't mount with "
5197 				 "both data=journal and delalloc");
5198 			err = -EINVAL;
5199 			goto restore_opts;
5200 		}
5201 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5202 			ext4_msg(sb, KERN_ERR, "can't mount with "
5203 				 "both data=journal and dioread_nolock");
5204 			err = -EINVAL;
5205 			goto restore_opts;
5206 		}
5207 		if (test_opt(sb, DAX)) {
5208 			ext4_msg(sb, KERN_ERR, "can't mount with "
5209 				 "both data=journal and dax");
5210 			err = -EINVAL;
5211 			goto restore_opts;
5212 		}
5213 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5214 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5215 			ext4_msg(sb, KERN_ERR, "can't mount with "
5216 				"journal_async_commit in data=ordered mode");
5217 			err = -EINVAL;
5218 			goto restore_opts;
5219 		}
5220 	}
5221 
5222 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5223 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5224 		err = -EINVAL;
5225 		goto restore_opts;
5226 	}
5227 
5228 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5229 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5230 			"dax flag with busy inodes while remounting");
5231 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5232 	}
5233 
5234 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5235 		ext4_abort(sb, "Abort forced by user");
5236 
5237 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5238 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5239 
5240 	es = sbi->s_es;
5241 
5242 	if (sbi->s_journal) {
5243 		ext4_init_journal_params(sb, sbi->s_journal);
5244 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5245 	}
5246 
5247 	if (*flags & SB_LAZYTIME)
5248 		sb->s_flags |= SB_LAZYTIME;
5249 
5250 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5251 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5252 			err = -EROFS;
5253 			goto restore_opts;
5254 		}
5255 
5256 		if (*flags & SB_RDONLY) {
5257 			err = sync_filesystem(sb);
5258 			if (err < 0)
5259 				goto restore_opts;
5260 			err = dquot_suspend(sb, -1);
5261 			if (err < 0)
5262 				goto restore_opts;
5263 
5264 			/*
5265 			 * First of all, the unconditional stuff we have to do
5266 			 * to disable replay of the journal when we next remount
5267 			 */
5268 			sb->s_flags |= SB_RDONLY;
5269 
5270 			/*
5271 			 * OK, test if we are remounting a valid rw partition
5272 			 * readonly, and if so set the rdonly flag and then
5273 			 * mark the partition as valid again.
5274 			 */
5275 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5276 			    (sbi->s_mount_state & EXT4_VALID_FS))
5277 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5278 
5279 			if (sbi->s_journal)
5280 				ext4_mark_recovery_complete(sb, es);
5281 			if (sbi->s_mmp_tsk)
5282 				kthread_stop(sbi->s_mmp_tsk);
5283 		} else {
5284 			/* Make sure we can mount this feature set readwrite */
5285 			if (ext4_has_feature_readonly(sb) ||
5286 			    !ext4_feature_set_ok(sb, 0)) {
5287 				err = -EROFS;
5288 				goto restore_opts;
5289 			}
5290 			/*
5291 			 * Make sure the group descriptor checksums
5292 			 * are sane.  If they aren't, refuse to remount r/w.
5293 			 */
5294 			for (g = 0; g < sbi->s_groups_count; g++) {
5295 				struct ext4_group_desc *gdp =
5296 					ext4_get_group_desc(sb, g, NULL);
5297 
5298 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5299 					ext4_msg(sb, KERN_ERR,
5300 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5301 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5302 					       le16_to_cpu(gdp->bg_checksum));
5303 					err = -EFSBADCRC;
5304 					goto restore_opts;
5305 				}
5306 			}
5307 
5308 			/*
5309 			 * If we have an unprocessed orphan list hanging
5310 			 * around from a previously readonly bdev mount,
5311 			 * require a full umount/remount for now.
5312 			 */
5313 			if (es->s_last_orphan) {
5314 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5315 				       "remount RDWR because of unprocessed "
5316 				       "orphan inode list.  Please "
5317 				       "umount/remount instead");
5318 				err = -EINVAL;
5319 				goto restore_opts;
5320 			}
5321 
5322 			/*
5323 			 * Mounting a RDONLY partition read-write, so reread
5324 			 * and store the current valid flag.  (It may have
5325 			 * been changed by e2fsck since we originally mounted
5326 			 * the partition.)
5327 			 */
5328 			if (sbi->s_journal)
5329 				ext4_clear_journal_err(sb, es);
5330 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5331 
5332 			err = ext4_setup_super(sb, es, 0);
5333 			if (err)
5334 				goto restore_opts;
5335 
5336 			sb->s_flags &= ~SB_RDONLY;
5337 			if (ext4_has_feature_mmp(sb))
5338 				if (ext4_multi_mount_protect(sb,
5339 						le64_to_cpu(es->s_mmp_block))) {
5340 					err = -EROFS;
5341 					goto restore_opts;
5342 				}
5343 			enable_quota = 1;
5344 		}
5345 	}
5346 
5347 	/*
5348 	 * Reinitialize lazy itable initialization thread based on
5349 	 * current settings
5350 	 */
5351 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5352 		ext4_unregister_li_request(sb);
5353 	else {
5354 		ext4_group_t first_not_zeroed;
5355 		first_not_zeroed = ext4_has_uninit_itable(sb);
5356 		ext4_register_li_request(sb, first_not_zeroed);
5357 	}
5358 
5359 	ext4_setup_system_zone(sb);
5360 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5361 		err = ext4_commit_super(sb, 1);
5362 		if (err)
5363 			goto restore_opts;
5364 	}
5365 
5366 #ifdef CONFIG_QUOTA
5367 	/* Release old quota file names */
5368 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5369 		kfree(old_opts.s_qf_names[i]);
5370 	if (enable_quota) {
5371 		if (sb_any_quota_suspended(sb))
5372 			dquot_resume(sb, -1);
5373 		else if (ext4_has_feature_quota(sb)) {
5374 			err = ext4_enable_quotas(sb);
5375 			if (err)
5376 				goto restore_opts;
5377 		}
5378 	}
5379 #endif
5380 
5381 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5382 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5383 	kfree(orig_data);
5384 	return 0;
5385 
5386 restore_opts:
5387 	sb->s_flags = old_sb_flags;
5388 	sbi->s_mount_opt = old_opts.s_mount_opt;
5389 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5390 	sbi->s_resuid = old_opts.s_resuid;
5391 	sbi->s_resgid = old_opts.s_resgid;
5392 	sbi->s_commit_interval = old_opts.s_commit_interval;
5393 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5394 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5395 #ifdef CONFIG_QUOTA
5396 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5397 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5398 		to_free[i] = get_qf_name(sb, sbi, i);
5399 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5400 	}
5401 	synchronize_rcu();
5402 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5403 		kfree(to_free[i]);
5404 #endif
5405 	kfree(orig_data);
5406 	return err;
5407 }
5408 
5409 #ifdef CONFIG_QUOTA
5410 static int ext4_statfs_project(struct super_block *sb,
5411 			       kprojid_t projid, struct kstatfs *buf)
5412 {
5413 	struct kqid qid;
5414 	struct dquot *dquot;
5415 	u64 limit;
5416 	u64 curblock;
5417 
5418 	qid = make_kqid_projid(projid);
5419 	dquot = dqget(sb, qid);
5420 	if (IS_ERR(dquot))
5421 		return PTR_ERR(dquot);
5422 	spin_lock(&dquot->dq_dqb_lock);
5423 
5424 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5425 		 dquot->dq_dqb.dqb_bsoftlimit :
5426 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5427 	if (limit && buf->f_blocks > limit) {
5428 		curblock = (dquot->dq_dqb.dqb_curspace +
5429 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5430 		buf->f_blocks = limit;
5431 		buf->f_bfree = buf->f_bavail =
5432 			(buf->f_blocks > curblock) ?
5433 			 (buf->f_blocks - curblock) : 0;
5434 	}
5435 
5436 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5437 		dquot->dq_dqb.dqb_isoftlimit :
5438 		dquot->dq_dqb.dqb_ihardlimit;
5439 	if (limit && buf->f_files > limit) {
5440 		buf->f_files = limit;
5441 		buf->f_ffree =
5442 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5443 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5444 	}
5445 
5446 	spin_unlock(&dquot->dq_dqb_lock);
5447 	dqput(dquot);
5448 	return 0;
5449 }
5450 #endif
5451 
5452 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5453 {
5454 	struct super_block *sb = dentry->d_sb;
5455 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5456 	struct ext4_super_block *es = sbi->s_es;
5457 	ext4_fsblk_t overhead = 0, resv_blocks;
5458 	u64 fsid;
5459 	s64 bfree;
5460 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5461 
5462 	if (!test_opt(sb, MINIX_DF))
5463 		overhead = sbi->s_overhead;
5464 
5465 	buf->f_type = EXT4_SUPER_MAGIC;
5466 	buf->f_bsize = sb->s_blocksize;
5467 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5468 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5469 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5470 	/* prevent underflow in case that few free space is available */
5471 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5472 	buf->f_bavail = buf->f_bfree -
5473 			(ext4_r_blocks_count(es) + resv_blocks);
5474 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5475 		buf->f_bavail = 0;
5476 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5477 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5478 	buf->f_namelen = EXT4_NAME_LEN;
5479 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5480 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5481 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5482 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5483 
5484 #ifdef CONFIG_QUOTA
5485 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5486 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5487 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5488 #endif
5489 	return 0;
5490 }
5491 
5492 
5493 #ifdef CONFIG_QUOTA
5494 
5495 /*
5496  * Helper functions so that transaction is started before we acquire dqio_sem
5497  * to keep correct lock ordering of transaction > dqio_sem
5498  */
5499 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5500 {
5501 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5502 }
5503 
5504 static int ext4_write_dquot(struct dquot *dquot)
5505 {
5506 	int ret, err;
5507 	handle_t *handle;
5508 	struct inode *inode;
5509 
5510 	inode = dquot_to_inode(dquot);
5511 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5512 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5513 	if (IS_ERR(handle))
5514 		return PTR_ERR(handle);
5515 	ret = dquot_commit(dquot);
5516 	err = ext4_journal_stop(handle);
5517 	if (!ret)
5518 		ret = err;
5519 	return ret;
5520 }
5521 
5522 static int ext4_acquire_dquot(struct dquot *dquot)
5523 {
5524 	int ret, err;
5525 	handle_t *handle;
5526 
5527 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5528 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5529 	if (IS_ERR(handle))
5530 		return PTR_ERR(handle);
5531 	ret = dquot_acquire(dquot);
5532 	err = ext4_journal_stop(handle);
5533 	if (!ret)
5534 		ret = err;
5535 	return ret;
5536 }
5537 
5538 static int ext4_release_dquot(struct dquot *dquot)
5539 {
5540 	int ret, err;
5541 	handle_t *handle;
5542 
5543 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5544 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5545 	if (IS_ERR(handle)) {
5546 		/* Release dquot anyway to avoid endless cycle in dqput() */
5547 		dquot_release(dquot);
5548 		return PTR_ERR(handle);
5549 	}
5550 	ret = dquot_release(dquot);
5551 	err = ext4_journal_stop(handle);
5552 	if (!ret)
5553 		ret = err;
5554 	return ret;
5555 }
5556 
5557 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5558 {
5559 	struct super_block *sb = dquot->dq_sb;
5560 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5561 
5562 	/* Are we journaling quotas? */
5563 	if (ext4_has_feature_quota(sb) ||
5564 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5565 		dquot_mark_dquot_dirty(dquot);
5566 		return ext4_write_dquot(dquot);
5567 	} else {
5568 		return dquot_mark_dquot_dirty(dquot);
5569 	}
5570 }
5571 
5572 static int ext4_write_info(struct super_block *sb, int type)
5573 {
5574 	int ret, err;
5575 	handle_t *handle;
5576 
5577 	/* Data block + inode block */
5578 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5579 	if (IS_ERR(handle))
5580 		return PTR_ERR(handle);
5581 	ret = dquot_commit_info(sb, type);
5582 	err = ext4_journal_stop(handle);
5583 	if (!ret)
5584 		ret = err;
5585 	return ret;
5586 }
5587 
5588 /*
5589  * Turn on quotas during mount time - we need to find
5590  * the quota file and such...
5591  */
5592 static int ext4_quota_on_mount(struct super_block *sb, int type)
5593 {
5594 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5595 					EXT4_SB(sb)->s_jquota_fmt, type);
5596 }
5597 
5598 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5599 {
5600 	struct ext4_inode_info *ei = EXT4_I(inode);
5601 
5602 	/* The first argument of lockdep_set_subclass has to be
5603 	 * *exactly* the same as the argument to init_rwsem() --- in
5604 	 * this case, in init_once() --- or lockdep gets unhappy
5605 	 * because the name of the lock is set using the
5606 	 * stringification of the argument to init_rwsem().
5607 	 */
5608 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5609 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5610 }
5611 
5612 /*
5613  * Standard function to be called on quota_on
5614  */
5615 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5616 			 const struct path *path)
5617 {
5618 	int err;
5619 
5620 	if (!test_opt(sb, QUOTA))
5621 		return -EINVAL;
5622 
5623 	/* Quotafile not on the same filesystem? */
5624 	if (path->dentry->d_sb != sb)
5625 		return -EXDEV;
5626 	/* Journaling quota? */
5627 	if (EXT4_SB(sb)->s_qf_names[type]) {
5628 		/* Quotafile not in fs root? */
5629 		if (path->dentry->d_parent != sb->s_root)
5630 			ext4_msg(sb, KERN_WARNING,
5631 				"Quota file not on filesystem root. "
5632 				"Journaled quota will not work");
5633 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5634 	} else {
5635 		/*
5636 		 * Clear the flag just in case mount options changed since
5637 		 * last time.
5638 		 */
5639 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5640 	}
5641 
5642 	/*
5643 	 * When we journal data on quota file, we have to flush journal to see
5644 	 * all updates to the file when we bypass pagecache...
5645 	 */
5646 	if (EXT4_SB(sb)->s_journal &&
5647 	    ext4_should_journal_data(d_inode(path->dentry))) {
5648 		/*
5649 		 * We don't need to lock updates but journal_flush() could
5650 		 * otherwise be livelocked...
5651 		 */
5652 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5653 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5654 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5655 		if (err)
5656 			return err;
5657 	}
5658 
5659 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5660 	err = dquot_quota_on(sb, type, format_id, path);
5661 	if (err) {
5662 		lockdep_set_quota_inode(path->dentry->d_inode,
5663 					     I_DATA_SEM_NORMAL);
5664 	} else {
5665 		struct inode *inode = d_inode(path->dentry);
5666 		handle_t *handle;
5667 
5668 		/*
5669 		 * Set inode flags to prevent userspace from messing with quota
5670 		 * files. If this fails, we return success anyway since quotas
5671 		 * are already enabled and this is not a hard failure.
5672 		 */
5673 		inode_lock(inode);
5674 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5675 		if (IS_ERR(handle))
5676 			goto unlock_inode;
5677 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5678 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5679 				S_NOATIME | S_IMMUTABLE);
5680 		ext4_mark_inode_dirty(handle, inode);
5681 		ext4_journal_stop(handle);
5682 	unlock_inode:
5683 		inode_unlock(inode);
5684 	}
5685 	return err;
5686 }
5687 
5688 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5689 			     unsigned int flags)
5690 {
5691 	int err;
5692 	struct inode *qf_inode;
5693 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5694 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5695 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5696 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5697 	};
5698 
5699 	BUG_ON(!ext4_has_feature_quota(sb));
5700 
5701 	if (!qf_inums[type])
5702 		return -EPERM;
5703 
5704 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5705 	if (IS_ERR(qf_inode)) {
5706 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5707 		return PTR_ERR(qf_inode);
5708 	}
5709 
5710 	/* Don't account quota for quota files to avoid recursion */
5711 	qf_inode->i_flags |= S_NOQUOTA;
5712 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5713 	err = dquot_enable(qf_inode, type, format_id, flags);
5714 	if (err)
5715 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5716 	iput(qf_inode);
5717 
5718 	return err;
5719 }
5720 
5721 /* Enable usage tracking for all quota types. */
5722 static int ext4_enable_quotas(struct super_block *sb)
5723 {
5724 	int type, err = 0;
5725 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5726 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5727 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5728 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5729 	};
5730 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5731 		test_opt(sb, USRQUOTA),
5732 		test_opt(sb, GRPQUOTA),
5733 		test_opt(sb, PRJQUOTA),
5734 	};
5735 
5736 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5737 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5738 		if (qf_inums[type]) {
5739 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5740 				DQUOT_USAGE_ENABLED |
5741 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5742 			if (err) {
5743 				ext4_warning(sb,
5744 					"Failed to enable quota tracking "
5745 					"(type=%d, err=%d). Please run "
5746 					"e2fsck to fix.", type, err);
5747 				for (type--; type >= 0; type--)
5748 					dquot_quota_off(sb, type);
5749 
5750 				return err;
5751 			}
5752 		}
5753 	}
5754 	return 0;
5755 }
5756 
5757 static int ext4_quota_off(struct super_block *sb, int type)
5758 {
5759 	struct inode *inode = sb_dqopt(sb)->files[type];
5760 	handle_t *handle;
5761 	int err;
5762 
5763 	/* Force all delayed allocation blocks to be allocated.
5764 	 * Caller already holds s_umount sem */
5765 	if (test_opt(sb, DELALLOC))
5766 		sync_filesystem(sb);
5767 
5768 	if (!inode || !igrab(inode))
5769 		goto out;
5770 
5771 	err = dquot_quota_off(sb, type);
5772 	if (err || ext4_has_feature_quota(sb))
5773 		goto out_put;
5774 
5775 	inode_lock(inode);
5776 	/*
5777 	 * Update modification times of quota files when userspace can
5778 	 * start looking at them. If we fail, we return success anyway since
5779 	 * this is not a hard failure and quotas are already disabled.
5780 	 */
5781 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5782 	if (IS_ERR(handle))
5783 		goto out_unlock;
5784 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5785 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5786 	inode->i_mtime = inode->i_ctime = current_time(inode);
5787 	ext4_mark_inode_dirty(handle, inode);
5788 	ext4_journal_stop(handle);
5789 out_unlock:
5790 	inode_unlock(inode);
5791 out_put:
5792 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5793 	iput(inode);
5794 	return err;
5795 out:
5796 	return dquot_quota_off(sb, type);
5797 }
5798 
5799 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5800  * acquiring the locks... As quota files are never truncated and quota code
5801  * itself serializes the operations (and no one else should touch the files)
5802  * we don't have to be afraid of races */
5803 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5804 			       size_t len, loff_t off)
5805 {
5806 	struct inode *inode = sb_dqopt(sb)->files[type];
5807 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5808 	int offset = off & (sb->s_blocksize - 1);
5809 	int tocopy;
5810 	size_t toread;
5811 	struct buffer_head *bh;
5812 	loff_t i_size = i_size_read(inode);
5813 
5814 	if (off > i_size)
5815 		return 0;
5816 	if (off+len > i_size)
5817 		len = i_size-off;
5818 	toread = len;
5819 	while (toread > 0) {
5820 		tocopy = sb->s_blocksize - offset < toread ?
5821 				sb->s_blocksize - offset : toread;
5822 		bh = ext4_bread(NULL, inode, blk, 0);
5823 		if (IS_ERR(bh))
5824 			return PTR_ERR(bh);
5825 		if (!bh)	/* A hole? */
5826 			memset(data, 0, tocopy);
5827 		else
5828 			memcpy(data, bh->b_data+offset, tocopy);
5829 		brelse(bh);
5830 		offset = 0;
5831 		toread -= tocopy;
5832 		data += tocopy;
5833 		blk++;
5834 	}
5835 	return len;
5836 }
5837 
5838 /* Write to quotafile (we know the transaction is already started and has
5839  * enough credits) */
5840 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5841 				const char *data, size_t len, loff_t off)
5842 {
5843 	struct inode *inode = sb_dqopt(sb)->files[type];
5844 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5845 	int err, offset = off & (sb->s_blocksize - 1);
5846 	int retries = 0;
5847 	struct buffer_head *bh;
5848 	handle_t *handle = journal_current_handle();
5849 
5850 	if (EXT4_SB(sb)->s_journal && !handle) {
5851 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5852 			" cancelled because transaction is not started",
5853 			(unsigned long long)off, (unsigned long long)len);
5854 		return -EIO;
5855 	}
5856 	/*
5857 	 * Since we account only one data block in transaction credits,
5858 	 * then it is impossible to cross a block boundary.
5859 	 */
5860 	if (sb->s_blocksize - offset < len) {
5861 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5862 			" cancelled because not block aligned",
5863 			(unsigned long long)off, (unsigned long long)len);
5864 		return -EIO;
5865 	}
5866 
5867 	do {
5868 		bh = ext4_bread(handle, inode, blk,
5869 				EXT4_GET_BLOCKS_CREATE |
5870 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5871 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5872 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5873 	if (IS_ERR(bh))
5874 		return PTR_ERR(bh);
5875 	if (!bh)
5876 		goto out;
5877 	BUFFER_TRACE(bh, "get write access");
5878 	err = ext4_journal_get_write_access(handle, bh);
5879 	if (err) {
5880 		brelse(bh);
5881 		return err;
5882 	}
5883 	lock_buffer(bh);
5884 	memcpy(bh->b_data+offset, data, len);
5885 	flush_dcache_page(bh->b_page);
5886 	unlock_buffer(bh);
5887 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5888 	brelse(bh);
5889 out:
5890 	if (inode->i_size < off + len) {
5891 		i_size_write(inode, off + len);
5892 		EXT4_I(inode)->i_disksize = inode->i_size;
5893 		ext4_mark_inode_dirty(handle, inode);
5894 	}
5895 	return len;
5896 }
5897 
5898 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5899 {
5900 	const struct quota_format_ops	*ops;
5901 
5902 	if (!sb_has_quota_loaded(sb, qid->type))
5903 		return -ESRCH;
5904 	ops = sb_dqopt(sb)->ops[qid->type];
5905 	if (!ops || !ops->get_next_id)
5906 		return -ENOSYS;
5907 	return dquot_get_next_id(sb, qid);
5908 }
5909 #endif
5910 
5911 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5912 		       const char *dev_name, void *data)
5913 {
5914 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5915 }
5916 
5917 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5918 static inline void register_as_ext2(void)
5919 {
5920 	int err = register_filesystem(&ext2_fs_type);
5921 	if (err)
5922 		printk(KERN_WARNING
5923 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5924 }
5925 
5926 static inline void unregister_as_ext2(void)
5927 {
5928 	unregister_filesystem(&ext2_fs_type);
5929 }
5930 
5931 static inline int ext2_feature_set_ok(struct super_block *sb)
5932 {
5933 	if (ext4_has_unknown_ext2_incompat_features(sb))
5934 		return 0;
5935 	if (sb_rdonly(sb))
5936 		return 1;
5937 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5938 		return 0;
5939 	return 1;
5940 }
5941 #else
5942 static inline void register_as_ext2(void) { }
5943 static inline void unregister_as_ext2(void) { }
5944 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5945 #endif
5946 
5947 static inline void register_as_ext3(void)
5948 {
5949 	int err = register_filesystem(&ext3_fs_type);
5950 	if (err)
5951 		printk(KERN_WARNING
5952 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5953 }
5954 
5955 static inline void unregister_as_ext3(void)
5956 {
5957 	unregister_filesystem(&ext3_fs_type);
5958 }
5959 
5960 static inline int ext3_feature_set_ok(struct super_block *sb)
5961 {
5962 	if (ext4_has_unknown_ext3_incompat_features(sb))
5963 		return 0;
5964 	if (!ext4_has_feature_journal(sb))
5965 		return 0;
5966 	if (sb_rdonly(sb))
5967 		return 1;
5968 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5969 		return 0;
5970 	return 1;
5971 }
5972 
5973 static struct file_system_type ext4_fs_type = {
5974 	.owner		= THIS_MODULE,
5975 	.name		= "ext4",
5976 	.mount		= ext4_mount,
5977 	.kill_sb	= kill_block_super,
5978 	.fs_flags	= FS_REQUIRES_DEV,
5979 };
5980 MODULE_ALIAS_FS("ext4");
5981 
5982 /* Shared across all ext4 file systems */
5983 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5984 
5985 static int __init ext4_init_fs(void)
5986 {
5987 	int i, err;
5988 
5989 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5990 	ext4_li_info = NULL;
5991 	mutex_init(&ext4_li_mtx);
5992 
5993 	/* Build-time check for flags consistency */
5994 	ext4_check_flag_values();
5995 
5996 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5997 		init_waitqueue_head(&ext4__ioend_wq[i]);
5998 
5999 	err = ext4_init_es();
6000 	if (err)
6001 		return err;
6002 
6003 	err = ext4_init_pending();
6004 	if (err)
6005 		goto out6;
6006 
6007 	err = ext4_init_pageio();
6008 	if (err)
6009 		goto out5;
6010 
6011 	err = ext4_init_system_zone();
6012 	if (err)
6013 		goto out4;
6014 
6015 	err = ext4_init_sysfs();
6016 	if (err)
6017 		goto out3;
6018 
6019 	err = ext4_init_mballoc();
6020 	if (err)
6021 		goto out2;
6022 	err = init_inodecache();
6023 	if (err)
6024 		goto out1;
6025 	register_as_ext3();
6026 	register_as_ext2();
6027 	err = register_filesystem(&ext4_fs_type);
6028 	if (err)
6029 		goto out;
6030 
6031 	return 0;
6032 out:
6033 	unregister_as_ext2();
6034 	unregister_as_ext3();
6035 	destroy_inodecache();
6036 out1:
6037 	ext4_exit_mballoc();
6038 out2:
6039 	ext4_exit_sysfs();
6040 out3:
6041 	ext4_exit_system_zone();
6042 out4:
6043 	ext4_exit_pageio();
6044 out5:
6045 	ext4_exit_pending();
6046 out6:
6047 	ext4_exit_es();
6048 
6049 	return err;
6050 }
6051 
6052 static void __exit ext4_exit_fs(void)
6053 {
6054 	ext4_destroy_lazyinit_thread();
6055 	unregister_as_ext2();
6056 	unregister_as_ext3();
6057 	unregister_filesystem(&ext4_fs_type);
6058 	destroy_inodecache();
6059 	ext4_exit_mballoc();
6060 	ext4_exit_sysfs();
6061 	ext4_exit_system_zone();
6062 	ext4_exit_pageio();
6063 	ext4_exit_es();
6064 	ext4_exit_pending();
6065 }
6066 
6067 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6068 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6069 MODULE_LICENSE("GPL");
6070 MODULE_SOFTDEP("pre: crc32c");
6071 module_init(ext4_init_fs)
6072 module_exit(ext4_exit_fs)
6073