xref: /openbmc/linux/fs/ext4/super.c (revision 8a363970d1dc38c4ec4ad575c862f776f468d057)
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 /*
1206  * Try to release metadata pages (indirect blocks, directories) which are
1207  * mapped via the block device.  Since these pages could have journal heads
1208  * which would prevent try_to_free_buffers() from freeing them, we must use
1209  * jbd2 layer's try_to_free_buffers() function to release them.
1210  */
1211 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1212 				 gfp_t wait)
1213 {
1214 	journal_t *journal = EXT4_SB(sb)->s_journal;
1215 
1216 	WARN_ON(PageChecked(page));
1217 	if (!page_has_buffers(page))
1218 		return 0;
1219 	if (journal)
1220 		return jbd2_journal_try_to_free_buffers(journal, page,
1221 						wait & ~__GFP_DIRECT_RECLAIM);
1222 	return try_to_free_buffers(page);
1223 }
1224 
1225 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1226 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1227 {
1228 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1229 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1230 }
1231 
1232 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1233 							void *fs_data)
1234 {
1235 	handle_t *handle = fs_data;
1236 	int res, res2, credits, retries = 0;
1237 
1238 	/*
1239 	 * Encrypting the root directory is not allowed because e2fsck expects
1240 	 * lost+found to exist and be unencrypted, and encrypting the root
1241 	 * directory would imply encrypting the lost+found directory as well as
1242 	 * the filename "lost+found" itself.
1243 	 */
1244 	if (inode->i_ino == EXT4_ROOT_INO)
1245 		return -EPERM;
1246 
1247 	if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
1248 		return -EINVAL;
1249 
1250 	res = ext4_convert_inline_data(inode);
1251 	if (res)
1252 		return res;
1253 
1254 	/*
1255 	 * If a journal handle was specified, then the encryption context is
1256 	 * being set on a new inode via inheritance and is part of a larger
1257 	 * transaction to create the inode.  Otherwise the encryption context is
1258 	 * being set on an existing inode in its own transaction.  Only in the
1259 	 * latter case should the "retry on ENOSPC" logic be used.
1260 	 */
1261 
1262 	if (handle) {
1263 		res = ext4_xattr_set_handle(handle, inode,
1264 					    EXT4_XATTR_INDEX_ENCRYPTION,
1265 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1266 					    ctx, len, 0);
1267 		if (!res) {
1268 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1269 			ext4_clear_inode_state(inode,
1270 					EXT4_STATE_MAY_INLINE_DATA);
1271 			/*
1272 			 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1273 			 * S_DAX may be disabled
1274 			 */
1275 			ext4_set_inode_flags(inode);
1276 		}
1277 		return res;
1278 	}
1279 
1280 	res = dquot_initialize(inode);
1281 	if (res)
1282 		return res;
1283 retry:
1284 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1285 				     &credits);
1286 	if (res)
1287 		return res;
1288 
1289 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1290 	if (IS_ERR(handle))
1291 		return PTR_ERR(handle);
1292 
1293 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1294 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1295 				    ctx, len, 0);
1296 	if (!res) {
1297 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1298 		/*
1299 		 * Update inode->i_flags - S_ENCRYPTED will be enabled,
1300 		 * S_DAX may be disabled
1301 		 */
1302 		ext4_set_inode_flags(inode);
1303 		res = ext4_mark_inode_dirty(handle, inode);
1304 		if (res)
1305 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1306 	}
1307 	res2 = ext4_journal_stop(handle);
1308 
1309 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1310 		goto retry;
1311 	if (!res)
1312 		res = res2;
1313 	return res;
1314 }
1315 
1316 static bool ext4_dummy_context(struct inode *inode)
1317 {
1318 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1319 }
1320 
1321 static const struct fscrypt_operations ext4_cryptops = {
1322 	.key_prefix		= "ext4:",
1323 	.get_context		= ext4_get_context,
1324 	.set_context		= ext4_set_context,
1325 	.dummy_context		= ext4_dummy_context,
1326 	.empty_dir		= ext4_empty_dir,
1327 	.max_namelen		= EXT4_NAME_LEN,
1328 };
1329 #endif
1330 
1331 #ifdef CONFIG_QUOTA
1332 static const char * const quotatypes[] = INITQFNAMES;
1333 #define QTYPE2NAME(t) (quotatypes[t])
1334 
1335 static int ext4_write_dquot(struct dquot *dquot);
1336 static int ext4_acquire_dquot(struct dquot *dquot);
1337 static int ext4_release_dquot(struct dquot *dquot);
1338 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1339 static int ext4_write_info(struct super_block *sb, int type);
1340 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1341 			 const struct path *path);
1342 static int ext4_quota_on_mount(struct super_block *sb, int type);
1343 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1344 			       size_t len, loff_t off);
1345 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1346 				const char *data, size_t len, loff_t off);
1347 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1348 			     unsigned int flags);
1349 static int ext4_enable_quotas(struct super_block *sb);
1350 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1351 
1352 static struct dquot **ext4_get_dquots(struct inode *inode)
1353 {
1354 	return EXT4_I(inode)->i_dquot;
1355 }
1356 
1357 static const struct dquot_operations ext4_quota_operations = {
1358 	.get_reserved_space	= ext4_get_reserved_space,
1359 	.write_dquot		= ext4_write_dquot,
1360 	.acquire_dquot		= ext4_acquire_dquot,
1361 	.release_dquot		= ext4_release_dquot,
1362 	.mark_dirty		= ext4_mark_dquot_dirty,
1363 	.write_info		= ext4_write_info,
1364 	.alloc_dquot		= dquot_alloc,
1365 	.destroy_dquot		= dquot_destroy,
1366 	.get_projid		= ext4_get_projid,
1367 	.get_inode_usage	= ext4_get_inode_usage,
1368 	.get_next_id		= ext4_get_next_id,
1369 };
1370 
1371 static const struct quotactl_ops ext4_qctl_operations = {
1372 	.quota_on	= ext4_quota_on,
1373 	.quota_off	= ext4_quota_off,
1374 	.quota_sync	= dquot_quota_sync,
1375 	.get_state	= dquot_get_state,
1376 	.set_info	= dquot_set_dqinfo,
1377 	.get_dqblk	= dquot_get_dqblk,
1378 	.set_dqblk	= dquot_set_dqblk,
1379 	.get_nextdqblk	= dquot_get_next_dqblk,
1380 };
1381 #endif
1382 
1383 static const struct super_operations ext4_sops = {
1384 	.alloc_inode	= ext4_alloc_inode,
1385 	.destroy_inode	= ext4_destroy_inode,
1386 	.write_inode	= ext4_write_inode,
1387 	.dirty_inode	= ext4_dirty_inode,
1388 	.drop_inode	= ext4_drop_inode,
1389 	.evict_inode	= ext4_evict_inode,
1390 	.put_super	= ext4_put_super,
1391 	.sync_fs	= ext4_sync_fs,
1392 	.freeze_fs	= ext4_freeze,
1393 	.unfreeze_fs	= ext4_unfreeze,
1394 	.statfs		= ext4_statfs,
1395 	.remount_fs	= ext4_remount,
1396 	.show_options	= ext4_show_options,
1397 #ifdef CONFIG_QUOTA
1398 	.quota_read	= ext4_quota_read,
1399 	.quota_write	= ext4_quota_write,
1400 	.get_dquots	= ext4_get_dquots,
1401 #endif
1402 	.bdev_try_to_free_page = bdev_try_to_free_page,
1403 };
1404 
1405 static const struct export_operations ext4_export_ops = {
1406 	.fh_to_dentry = ext4_fh_to_dentry,
1407 	.fh_to_parent = ext4_fh_to_parent,
1408 	.get_parent = ext4_get_parent,
1409 };
1410 
1411 enum {
1412 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1413 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1414 	Opt_nouid32, Opt_debug, Opt_removed,
1415 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1416 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1417 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1418 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1419 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1420 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1421 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1422 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1423 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1424 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1425 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error,
1426 	Opt_nowarn_on_error, Opt_mblk_io_submit,
1427 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1428 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1429 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1430 	Opt_dioread_nolock, Opt_dioread_lock,
1431 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1432 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1433 };
1434 
1435 static const match_table_t tokens = {
1436 	{Opt_bsd_df, "bsddf"},
1437 	{Opt_minix_df, "minixdf"},
1438 	{Opt_grpid, "grpid"},
1439 	{Opt_grpid, "bsdgroups"},
1440 	{Opt_nogrpid, "nogrpid"},
1441 	{Opt_nogrpid, "sysvgroups"},
1442 	{Opt_resgid, "resgid=%u"},
1443 	{Opt_resuid, "resuid=%u"},
1444 	{Opt_sb, "sb=%u"},
1445 	{Opt_err_cont, "errors=continue"},
1446 	{Opt_err_panic, "errors=panic"},
1447 	{Opt_err_ro, "errors=remount-ro"},
1448 	{Opt_nouid32, "nouid32"},
1449 	{Opt_debug, "debug"},
1450 	{Opt_removed, "oldalloc"},
1451 	{Opt_removed, "orlov"},
1452 	{Opt_user_xattr, "user_xattr"},
1453 	{Opt_nouser_xattr, "nouser_xattr"},
1454 	{Opt_acl, "acl"},
1455 	{Opt_noacl, "noacl"},
1456 	{Opt_noload, "norecovery"},
1457 	{Opt_noload, "noload"},
1458 	{Opt_removed, "nobh"},
1459 	{Opt_removed, "bh"},
1460 	{Opt_commit, "commit=%u"},
1461 	{Opt_min_batch_time, "min_batch_time=%u"},
1462 	{Opt_max_batch_time, "max_batch_time=%u"},
1463 	{Opt_journal_dev, "journal_dev=%u"},
1464 	{Opt_journal_path, "journal_path=%s"},
1465 	{Opt_journal_checksum, "journal_checksum"},
1466 	{Opt_nojournal_checksum, "nojournal_checksum"},
1467 	{Opt_journal_async_commit, "journal_async_commit"},
1468 	{Opt_abort, "abort"},
1469 	{Opt_data_journal, "data=journal"},
1470 	{Opt_data_ordered, "data=ordered"},
1471 	{Opt_data_writeback, "data=writeback"},
1472 	{Opt_data_err_abort, "data_err=abort"},
1473 	{Opt_data_err_ignore, "data_err=ignore"},
1474 	{Opt_offusrjquota, "usrjquota="},
1475 	{Opt_usrjquota, "usrjquota=%s"},
1476 	{Opt_offgrpjquota, "grpjquota="},
1477 	{Opt_grpjquota, "grpjquota=%s"},
1478 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1479 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1480 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1481 	{Opt_grpquota, "grpquota"},
1482 	{Opt_noquota, "noquota"},
1483 	{Opt_quota, "quota"},
1484 	{Opt_usrquota, "usrquota"},
1485 	{Opt_prjquota, "prjquota"},
1486 	{Opt_barrier, "barrier=%u"},
1487 	{Opt_barrier, "barrier"},
1488 	{Opt_nobarrier, "nobarrier"},
1489 	{Opt_i_version, "i_version"},
1490 	{Opt_dax, "dax"},
1491 	{Opt_stripe, "stripe=%u"},
1492 	{Opt_delalloc, "delalloc"},
1493 	{Opt_warn_on_error, "warn_on_error"},
1494 	{Opt_nowarn_on_error, "nowarn_on_error"},
1495 	{Opt_lazytime, "lazytime"},
1496 	{Opt_nolazytime, "nolazytime"},
1497 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1498 	{Opt_nodelalloc, "nodelalloc"},
1499 	{Opt_removed, "mblk_io_submit"},
1500 	{Opt_removed, "nomblk_io_submit"},
1501 	{Opt_block_validity, "block_validity"},
1502 	{Opt_noblock_validity, "noblock_validity"},
1503 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1504 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1505 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1506 	{Opt_auto_da_alloc, "auto_da_alloc"},
1507 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1508 	{Opt_dioread_nolock, "dioread_nolock"},
1509 	{Opt_dioread_lock, "dioread_lock"},
1510 	{Opt_discard, "discard"},
1511 	{Opt_nodiscard, "nodiscard"},
1512 	{Opt_init_itable, "init_itable=%u"},
1513 	{Opt_init_itable, "init_itable"},
1514 	{Opt_noinit_itable, "noinit_itable"},
1515 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1516 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1517 	{Opt_nombcache, "nombcache"},
1518 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1519 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1520 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1521 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1522 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1523 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1524 	{Opt_err, NULL},
1525 };
1526 
1527 static ext4_fsblk_t get_sb_block(void **data)
1528 {
1529 	ext4_fsblk_t	sb_block;
1530 	char		*options = (char *) *data;
1531 
1532 	if (!options || strncmp(options, "sb=", 3) != 0)
1533 		return 1;	/* Default location */
1534 
1535 	options += 3;
1536 	/* TODO: use simple_strtoll with >32bit ext4 */
1537 	sb_block = simple_strtoul(options, &options, 0);
1538 	if (*options && *options != ',') {
1539 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1540 		       (char *) *data);
1541 		return 1;
1542 	}
1543 	if (*options == ',')
1544 		options++;
1545 	*data = (void *) options;
1546 
1547 	return sb_block;
1548 }
1549 
1550 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1551 static const char deprecated_msg[] =
1552 	"Mount option \"%s\" will be removed by %s\n"
1553 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1554 
1555 #ifdef CONFIG_QUOTA
1556 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1557 {
1558 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1559 	char *qname, *old_qname = get_qf_name(sb, sbi, qtype);
1560 	int ret = -1;
1561 
1562 	if (sb_any_quota_loaded(sb) && !old_qname) {
1563 		ext4_msg(sb, KERN_ERR,
1564 			"Cannot change journaled "
1565 			"quota options when quota turned on");
1566 		return -1;
1567 	}
1568 	if (ext4_has_feature_quota(sb)) {
1569 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1570 			 "ignored when QUOTA feature is enabled");
1571 		return 1;
1572 	}
1573 	qname = match_strdup(args);
1574 	if (!qname) {
1575 		ext4_msg(sb, KERN_ERR,
1576 			"Not enough memory for storing quotafile name");
1577 		return -1;
1578 	}
1579 	if (old_qname) {
1580 		if (strcmp(old_qname, qname) == 0)
1581 			ret = 1;
1582 		else
1583 			ext4_msg(sb, KERN_ERR,
1584 				 "%s quota file already specified",
1585 				 QTYPE2NAME(qtype));
1586 		goto errout;
1587 	}
1588 	if (strchr(qname, '/')) {
1589 		ext4_msg(sb, KERN_ERR,
1590 			"quotafile must be on filesystem root");
1591 		goto errout;
1592 	}
1593 	rcu_assign_pointer(sbi->s_qf_names[qtype], qname);
1594 	set_opt(sb, QUOTA);
1595 	return 1;
1596 errout:
1597 	kfree(qname);
1598 	return ret;
1599 }
1600 
1601 static int clear_qf_name(struct super_block *sb, int qtype)
1602 {
1603 
1604 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1605 	char *old_qname = get_qf_name(sb, sbi, qtype);
1606 
1607 	if (sb_any_quota_loaded(sb) && old_qname) {
1608 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1609 			" when quota turned on");
1610 		return -1;
1611 	}
1612 	rcu_assign_pointer(sbi->s_qf_names[qtype], NULL);
1613 	synchronize_rcu();
1614 	kfree(old_qname);
1615 	return 1;
1616 }
1617 #endif
1618 
1619 #define MOPT_SET	0x0001
1620 #define MOPT_CLEAR	0x0002
1621 #define MOPT_NOSUPPORT	0x0004
1622 #define MOPT_EXPLICIT	0x0008
1623 #define MOPT_CLEAR_ERR	0x0010
1624 #define MOPT_GTE0	0x0020
1625 #ifdef CONFIG_QUOTA
1626 #define MOPT_Q		0
1627 #define MOPT_QFMT	0x0040
1628 #else
1629 #define MOPT_Q		MOPT_NOSUPPORT
1630 #define MOPT_QFMT	MOPT_NOSUPPORT
1631 #endif
1632 #define MOPT_DATAJ	0x0080
1633 #define MOPT_NO_EXT2	0x0100
1634 #define MOPT_NO_EXT3	0x0200
1635 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1636 #define MOPT_STRING	0x0400
1637 
1638 static const struct mount_opts {
1639 	int	token;
1640 	int	mount_opt;
1641 	int	flags;
1642 } ext4_mount_opts[] = {
1643 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1644 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1645 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1646 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1647 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1648 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1649 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1650 	 MOPT_EXT4_ONLY | MOPT_SET},
1651 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1652 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1653 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1654 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1655 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1656 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1657 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1658 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1659 	{Opt_warn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_SET},
1660 	{Opt_nowarn_on_error, EXT4_MOUNT_WARN_ON_ERROR, MOPT_CLEAR},
1661 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1662 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1663 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1664 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1665 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1666 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1667 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1668 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1669 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1670 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1671 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1672 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1673 	 MOPT_NO_EXT2},
1674 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1675 	 MOPT_NO_EXT2},
1676 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1677 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1678 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1679 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1680 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1681 	{Opt_commit, 0, MOPT_GTE0},
1682 	{Opt_max_batch_time, 0, MOPT_GTE0},
1683 	{Opt_min_batch_time, 0, MOPT_GTE0},
1684 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1685 	{Opt_init_itable, 0, MOPT_GTE0},
1686 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1687 	{Opt_stripe, 0, MOPT_GTE0},
1688 	{Opt_resuid, 0, MOPT_GTE0},
1689 	{Opt_resgid, 0, MOPT_GTE0},
1690 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1691 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1692 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1693 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1694 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1695 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1696 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1697 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1698 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1699 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1700 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1701 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1702 #else
1703 	{Opt_acl, 0, MOPT_NOSUPPORT},
1704 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1705 #endif
1706 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1707 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1708 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1709 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1710 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1711 							MOPT_SET | MOPT_Q},
1712 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1713 							MOPT_SET | MOPT_Q},
1714 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1715 							MOPT_SET | MOPT_Q},
1716 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1717 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1718 							MOPT_CLEAR | MOPT_Q},
1719 	{Opt_usrjquota, 0, MOPT_Q},
1720 	{Opt_grpjquota, 0, MOPT_Q},
1721 	{Opt_offusrjquota, 0, MOPT_Q},
1722 	{Opt_offgrpjquota, 0, MOPT_Q},
1723 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1724 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1725 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1726 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1727 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1728 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1729 	{Opt_err, 0, 0}
1730 };
1731 
1732 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1733 			    substring_t *args, unsigned long *journal_devnum,
1734 			    unsigned int *journal_ioprio, int is_remount)
1735 {
1736 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1737 	const struct mount_opts *m;
1738 	kuid_t uid;
1739 	kgid_t gid;
1740 	int arg = 0;
1741 
1742 #ifdef CONFIG_QUOTA
1743 	if (token == Opt_usrjquota)
1744 		return set_qf_name(sb, USRQUOTA, &args[0]);
1745 	else if (token == Opt_grpjquota)
1746 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1747 	else if (token == Opt_offusrjquota)
1748 		return clear_qf_name(sb, USRQUOTA);
1749 	else if (token == Opt_offgrpjquota)
1750 		return clear_qf_name(sb, GRPQUOTA);
1751 #endif
1752 	switch (token) {
1753 	case Opt_noacl:
1754 	case Opt_nouser_xattr:
1755 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1756 		break;
1757 	case Opt_sb:
1758 		return 1;	/* handled by get_sb_block() */
1759 	case Opt_removed:
1760 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1761 		return 1;
1762 	case Opt_abort:
1763 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1764 		return 1;
1765 	case Opt_i_version:
1766 		sb->s_flags |= SB_I_VERSION;
1767 		return 1;
1768 	case Opt_lazytime:
1769 		sb->s_flags |= SB_LAZYTIME;
1770 		return 1;
1771 	case Opt_nolazytime:
1772 		sb->s_flags &= ~SB_LAZYTIME;
1773 		return 1;
1774 	}
1775 
1776 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1777 		if (token == m->token)
1778 			break;
1779 
1780 	if (m->token == Opt_err) {
1781 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1782 			 "or missing value", opt);
1783 		return -1;
1784 	}
1785 
1786 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1787 		ext4_msg(sb, KERN_ERR,
1788 			 "Mount option \"%s\" incompatible with ext2", opt);
1789 		return -1;
1790 	}
1791 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1792 		ext4_msg(sb, KERN_ERR,
1793 			 "Mount option \"%s\" incompatible with ext3", opt);
1794 		return -1;
1795 	}
1796 
1797 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1798 		return -1;
1799 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1800 		return -1;
1801 	if (m->flags & MOPT_EXPLICIT) {
1802 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1803 			set_opt2(sb, EXPLICIT_DELALLOC);
1804 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1805 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1806 		} else
1807 			return -1;
1808 	}
1809 	if (m->flags & MOPT_CLEAR_ERR)
1810 		clear_opt(sb, ERRORS_MASK);
1811 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1812 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1813 			 "options when quota turned on");
1814 		return -1;
1815 	}
1816 
1817 	if (m->flags & MOPT_NOSUPPORT) {
1818 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1819 	} else if (token == Opt_commit) {
1820 		if (arg == 0)
1821 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1822 		sbi->s_commit_interval = HZ * arg;
1823 	} else if (token == Opt_debug_want_extra_isize) {
1824 		sbi->s_want_extra_isize = arg;
1825 	} else if (token == Opt_max_batch_time) {
1826 		sbi->s_max_batch_time = arg;
1827 	} else if (token == Opt_min_batch_time) {
1828 		sbi->s_min_batch_time = arg;
1829 	} else if (token == Opt_inode_readahead_blks) {
1830 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1831 			ext4_msg(sb, KERN_ERR,
1832 				 "EXT4-fs: inode_readahead_blks must be "
1833 				 "0 or a power of 2 smaller than 2^31");
1834 			return -1;
1835 		}
1836 		sbi->s_inode_readahead_blks = arg;
1837 	} else if (token == Opt_init_itable) {
1838 		set_opt(sb, INIT_INODE_TABLE);
1839 		if (!args->from)
1840 			arg = EXT4_DEF_LI_WAIT_MULT;
1841 		sbi->s_li_wait_mult = arg;
1842 	} else if (token == Opt_max_dir_size_kb) {
1843 		sbi->s_max_dir_size_kb = arg;
1844 	} else if (token == Opt_stripe) {
1845 		sbi->s_stripe = arg;
1846 	} else if (token == Opt_resuid) {
1847 		uid = make_kuid(current_user_ns(), arg);
1848 		if (!uid_valid(uid)) {
1849 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1850 			return -1;
1851 		}
1852 		sbi->s_resuid = uid;
1853 	} else if (token == Opt_resgid) {
1854 		gid = make_kgid(current_user_ns(), arg);
1855 		if (!gid_valid(gid)) {
1856 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1857 			return -1;
1858 		}
1859 		sbi->s_resgid = gid;
1860 	} else if (token == Opt_journal_dev) {
1861 		if (is_remount) {
1862 			ext4_msg(sb, KERN_ERR,
1863 				 "Cannot specify journal on remount");
1864 			return -1;
1865 		}
1866 		*journal_devnum = arg;
1867 	} else if (token == Opt_journal_path) {
1868 		char *journal_path;
1869 		struct inode *journal_inode;
1870 		struct path path;
1871 		int error;
1872 
1873 		if (is_remount) {
1874 			ext4_msg(sb, KERN_ERR,
1875 				 "Cannot specify journal on remount");
1876 			return -1;
1877 		}
1878 		journal_path = match_strdup(&args[0]);
1879 		if (!journal_path) {
1880 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1881 				"journal device string");
1882 			return -1;
1883 		}
1884 
1885 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1886 		if (error) {
1887 			ext4_msg(sb, KERN_ERR, "error: could not find "
1888 				"journal device path: error %d", error);
1889 			kfree(journal_path);
1890 			return -1;
1891 		}
1892 
1893 		journal_inode = d_inode(path.dentry);
1894 		if (!S_ISBLK(journal_inode->i_mode)) {
1895 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1896 				"is not a block device", journal_path);
1897 			path_put(&path);
1898 			kfree(journal_path);
1899 			return -1;
1900 		}
1901 
1902 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1903 		path_put(&path);
1904 		kfree(journal_path);
1905 	} else if (token == Opt_journal_ioprio) {
1906 		if (arg > 7) {
1907 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1908 				 " (must be 0-7)");
1909 			return -1;
1910 		}
1911 		*journal_ioprio =
1912 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1913 	} else if (token == Opt_test_dummy_encryption) {
1914 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1915 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1916 		ext4_msg(sb, KERN_WARNING,
1917 			 "Test dummy encryption mode enabled");
1918 #else
1919 		ext4_msg(sb, KERN_WARNING,
1920 			 "Test dummy encryption mount option ignored");
1921 #endif
1922 	} else if (m->flags & MOPT_DATAJ) {
1923 		if (is_remount) {
1924 			if (!sbi->s_journal)
1925 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1926 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1927 				ext4_msg(sb, KERN_ERR,
1928 					 "Cannot change data mode on remount");
1929 				return -1;
1930 			}
1931 		} else {
1932 			clear_opt(sb, DATA_FLAGS);
1933 			sbi->s_mount_opt |= m->mount_opt;
1934 		}
1935 #ifdef CONFIG_QUOTA
1936 	} else if (m->flags & MOPT_QFMT) {
1937 		if (sb_any_quota_loaded(sb) &&
1938 		    sbi->s_jquota_fmt != m->mount_opt) {
1939 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1940 				 "quota options when quota turned on");
1941 			return -1;
1942 		}
1943 		if (ext4_has_feature_quota(sb)) {
1944 			ext4_msg(sb, KERN_INFO,
1945 				 "Quota format mount options ignored "
1946 				 "when QUOTA feature is enabled");
1947 			return 1;
1948 		}
1949 		sbi->s_jquota_fmt = m->mount_opt;
1950 #endif
1951 	} else if (token == Opt_dax) {
1952 #ifdef CONFIG_FS_DAX
1953 		ext4_msg(sb, KERN_WARNING,
1954 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1955 		sbi->s_mount_opt |= m->mount_opt;
1956 #else
1957 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1958 		return -1;
1959 #endif
1960 	} else if (token == Opt_data_err_abort) {
1961 		sbi->s_mount_opt |= m->mount_opt;
1962 	} else if (token == Opt_data_err_ignore) {
1963 		sbi->s_mount_opt &= ~m->mount_opt;
1964 	} else {
1965 		if (!args->from)
1966 			arg = 1;
1967 		if (m->flags & MOPT_CLEAR)
1968 			arg = !arg;
1969 		else if (unlikely(!(m->flags & MOPT_SET))) {
1970 			ext4_msg(sb, KERN_WARNING,
1971 				 "buggy handling of option %s", opt);
1972 			WARN_ON(1);
1973 			return -1;
1974 		}
1975 		if (arg != 0)
1976 			sbi->s_mount_opt |= m->mount_opt;
1977 		else
1978 			sbi->s_mount_opt &= ~m->mount_opt;
1979 	}
1980 	return 1;
1981 }
1982 
1983 static int parse_options(char *options, struct super_block *sb,
1984 			 unsigned long *journal_devnum,
1985 			 unsigned int *journal_ioprio,
1986 			 int is_remount)
1987 {
1988 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1989 	char *p, __maybe_unused *usr_qf_name, __maybe_unused *grp_qf_name;
1990 	substring_t args[MAX_OPT_ARGS];
1991 	int token;
1992 
1993 	if (!options)
1994 		return 1;
1995 
1996 	while ((p = strsep(&options, ",")) != NULL) {
1997 		if (!*p)
1998 			continue;
1999 		/*
2000 		 * Initialize args struct so we know whether arg was
2001 		 * found; some options take optional arguments.
2002 		 */
2003 		args[0].to = args[0].from = NULL;
2004 		token = match_token(p, tokens, args);
2005 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
2006 				     journal_ioprio, is_remount) < 0)
2007 			return 0;
2008 	}
2009 #ifdef CONFIG_QUOTA
2010 	/*
2011 	 * We do the test below only for project quotas. 'usrquota' and
2012 	 * 'grpquota' mount options are allowed even without quota feature
2013 	 * to support legacy quotas in quota files.
2014 	 */
2015 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
2016 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
2017 			 "Cannot enable project quota enforcement.");
2018 		return 0;
2019 	}
2020 	usr_qf_name = get_qf_name(sb, sbi, USRQUOTA);
2021 	grp_qf_name = get_qf_name(sb, sbi, GRPQUOTA);
2022 	if (usr_qf_name || grp_qf_name) {
2023 		if (test_opt(sb, USRQUOTA) && usr_qf_name)
2024 			clear_opt(sb, USRQUOTA);
2025 
2026 		if (test_opt(sb, GRPQUOTA) && grp_qf_name)
2027 			clear_opt(sb, GRPQUOTA);
2028 
2029 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
2030 			ext4_msg(sb, KERN_ERR, "old and new quota "
2031 					"format mixing");
2032 			return 0;
2033 		}
2034 
2035 		if (!sbi->s_jquota_fmt) {
2036 			ext4_msg(sb, KERN_ERR, "journaled quota format "
2037 					"not specified");
2038 			return 0;
2039 		}
2040 	}
2041 #endif
2042 	if (test_opt(sb, DIOREAD_NOLOCK)) {
2043 		int blocksize =
2044 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
2045 
2046 		if (blocksize < PAGE_SIZE) {
2047 			ext4_msg(sb, KERN_ERR, "can't mount with "
2048 				 "dioread_nolock if block size != PAGE_SIZE");
2049 			return 0;
2050 		}
2051 	}
2052 	return 1;
2053 }
2054 
2055 static inline void ext4_show_quota_options(struct seq_file *seq,
2056 					   struct super_block *sb)
2057 {
2058 #if defined(CONFIG_QUOTA)
2059 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2060 	char *usr_qf_name, *grp_qf_name;
2061 
2062 	if (sbi->s_jquota_fmt) {
2063 		char *fmtname = "";
2064 
2065 		switch (sbi->s_jquota_fmt) {
2066 		case QFMT_VFS_OLD:
2067 			fmtname = "vfsold";
2068 			break;
2069 		case QFMT_VFS_V0:
2070 			fmtname = "vfsv0";
2071 			break;
2072 		case QFMT_VFS_V1:
2073 			fmtname = "vfsv1";
2074 			break;
2075 		}
2076 		seq_printf(seq, ",jqfmt=%s", fmtname);
2077 	}
2078 
2079 	rcu_read_lock();
2080 	usr_qf_name = rcu_dereference(sbi->s_qf_names[USRQUOTA]);
2081 	grp_qf_name = rcu_dereference(sbi->s_qf_names[GRPQUOTA]);
2082 	if (usr_qf_name)
2083 		seq_show_option(seq, "usrjquota", usr_qf_name);
2084 	if (grp_qf_name)
2085 		seq_show_option(seq, "grpjquota", grp_qf_name);
2086 	rcu_read_unlock();
2087 #endif
2088 }
2089 
2090 static const char *token2str(int token)
2091 {
2092 	const struct match_token *t;
2093 
2094 	for (t = tokens; t->token != Opt_err; t++)
2095 		if (t->token == token && !strchr(t->pattern, '='))
2096 			break;
2097 	return t->pattern;
2098 }
2099 
2100 /*
2101  * Show an option if
2102  *  - it's set to a non-default value OR
2103  *  - if the per-sb default is different from the global default
2104  */
2105 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2106 			      int nodefs)
2107 {
2108 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2109 	struct ext4_super_block *es = sbi->s_es;
2110 	int def_errors, def_mount_opt = sbi->s_def_mount_opt;
2111 	const struct mount_opts *m;
2112 	char sep = nodefs ? '\n' : ',';
2113 
2114 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2115 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2116 
2117 	if (sbi->s_sb_block != 1)
2118 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2119 
2120 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2121 		int want_set = m->flags & MOPT_SET;
2122 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2123 		    (m->flags & MOPT_CLEAR_ERR))
2124 			continue;
2125 		if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2126 			continue; /* skip if same as the default */
2127 		if ((want_set &&
2128 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2129 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2130 			continue; /* select Opt_noFoo vs Opt_Foo */
2131 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2132 	}
2133 
2134 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2135 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2136 		SEQ_OPTS_PRINT("resuid=%u",
2137 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2138 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2139 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2140 		SEQ_OPTS_PRINT("resgid=%u",
2141 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2142 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2143 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2144 		SEQ_OPTS_PUTS("errors=remount-ro");
2145 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2146 		SEQ_OPTS_PUTS("errors=continue");
2147 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2148 		SEQ_OPTS_PUTS("errors=panic");
2149 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2150 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2151 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2152 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2153 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2154 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2155 	if (sb->s_flags & SB_I_VERSION)
2156 		SEQ_OPTS_PUTS("i_version");
2157 	if (nodefs || sbi->s_stripe)
2158 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2159 	if (nodefs || EXT4_MOUNT_DATA_FLAGS &
2160 			(sbi->s_mount_opt ^ def_mount_opt)) {
2161 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2162 			SEQ_OPTS_PUTS("data=journal");
2163 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2164 			SEQ_OPTS_PUTS("data=ordered");
2165 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2166 			SEQ_OPTS_PUTS("data=writeback");
2167 	}
2168 	if (nodefs ||
2169 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2170 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2171 			       sbi->s_inode_readahead_blks);
2172 
2173 	if (test_opt(sb, INIT_INODE_TABLE) && (nodefs ||
2174 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2175 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2176 	if (nodefs || sbi->s_max_dir_size_kb)
2177 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2178 	if (test_opt(sb, DATA_ERR_ABORT))
2179 		SEQ_OPTS_PUTS("data_err=abort");
2180 	if (DUMMY_ENCRYPTION_ENABLED(sbi))
2181 		SEQ_OPTS_PUTS("test_dummy_encryption");
2182 
2183 	ext4_show_quota_options(seq, sb);
2184 	return 0;
2185 }
2186 
2187 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2188 {
2189 	return _ext4_show_options(seq, root->d_sb, 0);
2190 }
2191 
2192 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2193 {
2194 	struct super_block *sb = seq->private;
2195 	int rc;
2196 
2197 	seq_puts(seq, sb_rdonly(sb) ? "ro" : "rw");
2198 	rc = _ext4_show_options(seq, sb, 1);
2199 	seq_puts(seq, "\n");
2200 	return rc;
2201 }
2202 
2203 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2204 			    int read_only)
2205 {
2206 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2207 	int err = 0;
2208 
2209 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2210 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2211 			 "forcing read-only mode");
2212 		err = -EROFS;
2213 	}
2214 	if (read_only)
2215 		goto done;
2216 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2217 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2218 			 "running e2fsck is recommended");
2219 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2220 		ext4_msg(sb, KERN_WARNING,
2221 			 "warning: mounting fs with errors, "
2222 			 "running e2fsck is recommended");
2223 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2224 		 le16_to_cpu(es->s_mnt_count) >=
2225 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2226 		ext4_msg(sb, KERN_WARNING,
2227 			 "warning: maximal mount count reached, "
2228 			 "running e2fsck is recommended");
2229 	else if (le32_to_cpu(es->s_checkinterval) &&
2230 		 (ext4_get_tstamp(es, s_lastcheck) +
2231 		  le32_to_cpu(es->s_checkinterval) <= ktime_get_real_seconds()))
2232 		ext4_msg(sb, KERN_WARNING,
2233 			 "warning: checktime reached, "
2234 			 "running e2fsck is recommended");
2235 	if (!sbi->s_journal)
2236 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2237 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2238 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2239 	le16_add_cpu(&es->s_mnt_count, 1);
2240 	ext4_update_tstamp(es, s_mtime);
2241 	ext4_update_dynamic_rev(sb);
2242 	if (sbi->s_journal)
2243 		ext4_set_feature_journal_needs_recovery(sb);
2244 
2245 	err = ext4_commit_super(sb, 1);
2246 done:
2247 	if (test_opt(sb, DEBUG))
2248 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2249 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2250 			sb->s_blocksize,
2251 			sbi->s_groups_count,
2252 			EXT4_BLOCKS_PER_GROUP(sb),
2253 			EXT4_INODES_PER_GROUP(sb),
2254 			sbi->s_mount_opt, sbi->s_mount_opt2);
2255 
2256 	cleancache_init_fs(sb);
2257 	return err;
2258 }
2259 
2260 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2261 {
2262 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2263 	struct flex_groups *new_groups;
2264 	int size;
2265 
2266 	if (!sbi->s_log_groups_per_flex)
2267 		return 0;
2268 
2269 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2270 	if (size <= sbi->s_flex_groups_allocated)
2271 		return 0;
2272 
2273 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2274 	new_groups = kvzalloc(size, GFP_KERNEL);
2275 	if (!new_groups) {
2276 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2277 			 size / (int) sizeof(struct flex_groups));
2278 		return -ENOMEM;
2279 	}
2280 
2281 	if (sbi->s_flex_groups) {
2282 		memcpy(new_groups, sbi->s_flex_groups,
2283 		       (sbi->s_flex_groups_allocated *
2284 			sizeof(struct flex_groups)));
2285 		kvfree(sbi->s_flex_groups);
2286 	}
2287 	sbi->s_flex_groups = new_groups;
2288 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2289 	return 0;
2290 }
2291 
2292 static int ext4_fill_flex_info(struct super_block *sb)
2293 {
2294 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2295 	struct ext4_group_desc *gdp = NULL;
2296 	ext4_group_t flex_group;
2297 	int i, err;
2298 
2299 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2300 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2301 		sbi->s_log_groups_per_flex = 0;
2302 		return 1;
2303 	}
2304 
2305 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2306 	if (err)
2307 		goto failed;
2308 
2309 	for (i = 0; i < sbi->s_groups_count; i++) {
2310 		gdp = ext4_get_group_desc(sb, i, NULL);
2311 
2312 		flex_group = ext4_flex_group(sbi, i);
2313 		atomic_add(ext4_free_inodes_count(sb, gdp),
2314 			   &sbi->s_flex_groups[flex_group].free_inodes);
2315 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2316 			     &sbi->s_flex_groups[flex_group].free_clusters);
2317 		atomic_add(ext4_used_dirs_count(sb, gdp),
2318 			   &sbi->s_flex_groups[flex_group].used_dirs);
2319 	}
2320 
2321 	return 1;
2322 failed:
2323 	return 0;
2324 }
2325 
2326 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2327 				   struct ext4_group_desc *gdp)
2328 {
2329 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2330 	__u16 crc = 0;
2331 	__le32 le_group = cpu_to_le32(block_group);
2332 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2333 
2334 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2335 		/* Use new metadata_csum algorithm */
2336 		__u32 csum32;
2337 		__u16 dummy_csum = 0;
2338 
2339 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2340 				     sizeof(le_group));
2341 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2342 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2343 				     sizeof(dummy_csum));
2344 		offset += sizeof(dummy_csum);
2345 		if (offset < sbi->s_desc_size)
2346 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2347 					     sbi->s_desc_size - offset);
2348 
2349 		crc = csum32 & 0xFFFF;
2350 		goto out;
2351 	}
2352 
2353 	/* old crc16 code */
2354 	if (!ext4_has_feature_gdt_csum(sb))
2355 		return 0;
2356 
2357 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2358 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2359 	crc = crc16(crc, (__u8 *)gdp, offset);
2360 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2361 	/* for checksum of struct ext4_group_desc do the rest...*/
2362 	if (ext4_has_feature_64bit(sb) &&
2363 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2364 		crc = crc16(crc, (__u8 *)gdp + offset,
2365 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2366 				offset);
2367 
2368 out:
2369 	return cpu_to_le16(crc);
2370 }
2371 
2372 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2373 				struct ext4_group_desc *gdp)
2374 {
2375 	if (ext4_has_group_desc_csum(sb) &&
2376 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2377 		return 0;
2378 
2379 	return 1;
2380 }
2381 
2382 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2383 			      struct ext4_group_desc *gdp)
2384 {
2385 	if (!ext4_has_group_desc_csum(sb))
2386 		return;
2387 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2388 }
2389 
2390 /* Called at mount-time, super-block is locked */
2391 static int ext4_check_descriptors(struct super_block *sb,
2392 				  ext4_fsblk_t sb_block,
2393 				  ext4_group_t *first_not_zeroed)
2394 {
2395 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2396 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2397 	ext4_fsblk_t last_block;
2398 	ext4_fsblk_t last_bg_block = sb_block + ext4_bg_num_gdb(sb, 0);
2399 	ext4_fsblk_t block_bitmap;
2400 	ext4_fsblk_t inode_bitmap;
2401 	ext4_fsblk_t inode_table;
2402 	int flexbg_flag = 0;
2403 	ext4_group_t i, grp = sbi->s_groups_count;
2404 
2405 	if (ext4_has_feature_flex_bg(sb))
2406 		flexbg_flag = 1;
2407 
2408 	ext4_debug("Checking group descriptors");
2409 
2410 	for (i = 0; i < sbi->s_groups_count; i++) {
2411 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2412 
2413 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2414 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2415 		else
2416 			last_block = first_block +
2417 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2418 
2419 		if ((grp == sbi->s_groups_count) &&
2420 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2421 			grp = i;
2422 
2423 		block_bitmap = ext4_block_bitmap(sb, gdp);
2424 		if (block_bitmap == sb_block) {
2425 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2426 				 "Block bitmap for group %u overlaps "
2427 				 "superblock", i);
2428 			if (!sb_rdonly(sb))
2429 				return 0;
2430 		}
2431 		if (block_bitmap >= sb_block + 1 &&
2432 		    block_bitmap <= last_bg_block) {
2433 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2434 				 "Block bitmap for group %u overlaps "
2435 				 "block group descriptors", i);
2436 			if (!sb_rdonly(sb))
2437 				return 0;
2438 		}
2439 		if (block_bitmap < first_block || block_bitmap > last_block) {
2440 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2441 			       "Block bitmap for group %u not in group "
2442 			       "(block %llu)!", i, block_bitmap);
2443 			return 0;
2444 		}
2445 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2446 		if (inode_bitmap == sb_block) {
2447 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2448 				 "Inode bitmap for group %u overlaps "
2449 				 "superblock", i);
2450 			if (!sb_rdonly(sb))
2451 				return 0;
2452 		}
2453 		if (inode_bitmap >= sb_block + 1 &&
2454 		    inode_bitmap <= last_bg_block) {
2455 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2456 				 "Inode bitmap for group %u overlaps "
2457 				 "block group descriptors", i);
2458 			if (!sb_rdonly(sb))
2459 				return 0;
2460 		}
2461 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2462 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2463 			       "Inode bitmap for group %u not in group "
2464 			       "(block %llu)!", i, inode_bitmap);
2465 			return 0;
2466 		}
2467 		inode_table = ext4_inode_table(sb, gdp);
2468 		if (inode_table == sb_block) {
2469 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2470 				 "Inode table for group %u overlaps "
2471 				 "superblock", i);
2472 			if (!sb_rdonly(sb))
2473 				return 0;
2474 		}
2475 		if (inode_table >= sb_block + 1 &&
2476 		    inode_table <= last_bg_block) {
2477 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2478 				 "Inode table for group %u overlaps "
2479 				 "block group descriptors", i);
2480 			if (!sb_rdonly(sb))
2481 				return 0;
2482 		}
2483 		if (inode_table < first_block ||
2484 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2485 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2486 			       "Inode table for group %u not in group "
2487 			       "(block %llu)!", i, inode_table);
2488 			return 0;
2489 		}
2490 		ext4_lock_group(sb, i);
2491 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2492 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2493 				 "Checksum for group %u failed (%u!=%u)",
2494 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2495 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2496 			if (!sb_rdonly(sb)) {
2497 				ext4_unlock_group(sb, i);
2498 				return 0;
2499 			}
2500 		}
2501 		ext4_unlock_group(sb, i);
2502 		if (!flexbg_flag)
2503 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2504 	}
2505 	if (NULL != first_not_zeroed)
2506 		*first_not_zeroed = grp;
2507 	return 1;
2508 }
2509 
2510 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2511  * the superblock) which were deleted from all directories, but held open by
2512  * a process at the time of a crash.  We walk the list and try to delete these
2513  * inodes at recovery time (only with a read-write filesystem).
2514  *
2515  * In order to keep the orphan inode chain consistent during traversal (in
2516  * case of crash during recovery), we link each inode into the superblock
2517  * orphan list_head and handle it the same way as an inode deletion during
2518  * normal operation (which journals the operations for us).
2519  *
2520  * We only do an iget() and an iput() on each inode, which is very safe if we
2521  * accidentally point at an in-use or already deleted inode.  The worst that
2522  * can happen in this case is that we get a "bit already cleared" message from
2523  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2524  * e2fsck was run on this filesystem, and it must have already done the orphan
2525  * inode cleanup for us, so we can safely abort without any further action.
2526  */
2527 static void ext4_orphan_cleanup(struct super_block *sb,
2528 				struct ext4_super_block *es)
2529 {
2530 	unsigned int s_flags = sb->s_flags;
2531 	int ret, nr_orphans = 0, nr_truncates = 0;
2532 #ifdef CONFIG_QUOTA
2533 	int quota_update = 0;
2534 	int i;
2535 #endif
2536 	if (!es->s_last_orphan) {
2537 		jbd_debug(4, "no orphan inodes to clean up\n");
2538 		return;
2539 	}
2540 
2541 	if (bdev_read_only(sb->s_bdev)) {
2542 		ext4_msg(sb, KERN_ERR, "write access "
2543 			"unavailable, skipping orphan cleanup");
2544 		return;
2545 	}
2546 
2547 	/* Check if feature set would not allow a r/w mount */
2548 	if (!ext4_feature_set_ok(sb, 0)) {
2549 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2550 			 "unknown ROCOMPAT features");
2551 		return;
2552 	}
2553 
2554 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2555 		/* don't clear list on RO mount w/ errors */
2556 		if (es->s_last_orphan && !(s_flags & SB_RDONLY)) {
2557 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2558 				  "clearing orphan list.\n");
2559 			es->s_last_orphan = 0;
2560 		}
2561 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2562 		return;
2563 	}
2564 
2565 	if (s_flags & SB_RDONLY) {
2566 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2567 		sb->s_flags &= ~SB_RDONLY;
2568 	}
2569 #ifdef CONFIG_QUOTA
2570 	/* Needed for iput() to work correctly and not trash data */
2571 	sb->s_flags |= SB_ACTIVE;
2572 
2573 	/*
2574 	 * Turn on quotas which were not enabled for read-only mounts if
2575 	 * filesystem has quota feature, so that they are updated correctly.
2576 	 */
2577 	if (ext4_has_feature_quota(sb) && (s_flags & SB_RDONLY)) {
2578 		int ret = ext4_enable_quotas(sb);
2579 
2580 		if (!ret)
2581 			quota_update = 1;
2582 		else
2583 			ext4_msg(sb, KERN_ERR,
2584 				"Cannot turn on quotas: error %d", ret);
2585 	}
2586 
2587 	/* Turn on journaled quotas used for old sytle */
2588 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2589 		if (EXT4_SB(sb)->s_qf_names[i]) {
2590 			int ret = ext4_quota_on_mount(sb, i);
2591 
2592 			if (!ret)
2593 				quota_update = 1;
2594 			else
2595 				ext4_msg(sb, KERN_ERR,
2596 					"Cannot turn on journaled "
2597 					"quota: type %d: error %d", i, ret);
2598 		}
2599 	}
2600 #endif
2601 
2602 	while (es->s_last_orphan) {
2603 		struct inode *inode;
2604 
2605 		/*
2606 		 * We may have encountered an error during cleanup; if
2607 		 * so, skip the rest.
2608 		 */
2609 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2610 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2611 			es->s_last_orphan = 0;
2612 			break;
2613 		}
2614 
2615 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2616 		if (IS_ERR(inode)) {
2617 			es->s_last_orphan = 0;
2618 			break;
2619 		}
2620 
2621 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2622 		dquot_initialize(inode);
2623 		if (inode->i_nlink) {
2624 			if (test_opt(sb, DEBUG))
2625 				ext4_msg(sb, KERN_DEBUG,
2626 					"%s: truncating inode %lu to %lld bytes",
2627 					__func__, inode->i_ino, inode->i_size);
2628 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2629 				  inode->i_ino, inode->i_size);
2630 			inode_lock(inode);
2631 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2632 			ret = ext4_truncate(inode);
2633 			if (ret)
2634 				ext4_std_error(inode->i_sb, ret);
2635 			inode_unlock(inode);
2636 			nr_truncates++;
2637 		} else {
2638 			if (test_opt(sb, DEBUG))
2639 				ext4_msg(sb, KERN_DEBUG,
2640 					"%s: deleting unreferenced inode %lu",
2641 					__func__, inode->i_ino);
2642 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2643 				  inode->i_ino);
2644 			nr_orphans++;
2645 		}
2646 		iput(inode);  /* The delete magic happens here! */
2647 	}
2648 
2649 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2650 
2651 	if (nr_orphans)
2652 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2653 		       PLURAL(nr_orphans));
2654 	if (nr_truncates)
2655 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2656 		       PLURAL(nr_truncates));
2657 #ifdef CONFIG_QUOTA
2658 	/* Turn off quotas if they were enabled for orphan cleanup */
2659 	if (quota_update) {
2660 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2661 			if (sb_dqopt(sb)->files[i])
2662 				dquot_quota_off(sb, i);
2663 		}
2664 	}
2665 #endif
2666 	sb->s_flags = s_flags; /* Restore SB_RDONLY status */
2667 }
2668 
2669 /*
2670  * Maximal extent format file size.
2671  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2672  * extent format containers, within a sector_t, and within i_blocks
2673  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2674  * so that won't be a limiting factor.
2675  *
2676  * However there is other limiting factor. We do store extents in the form
2677  * of starting block and length, hence the resulting length of the extent
2678  * covering maximum file size must fit into on-disk format containers as
2679  * well. Given that length is always by 1 unit bigger than max unit (because
2680  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2681  *
2682  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2683  */
2684 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2685 {
2686 	loff_t res;
2687 	loff_t upper_limit = MAX_LFS_FILESIZE;
2688 
2689 	/* small i_blocks in vfs inode? */
2690 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2691 		/*
2692 		 * CONFIG_LBDAF is not enabled implies the inode
2693 		 * i_block represent total blocks in 512 bytes
2694 		 * 32 == size of vfs inode i_blocks * 8
2695 		 */
2696 		upper_limit = (1LL << 32) - 1;
2697 
2698 		/* total blocks in file system block size */
2699 		upper_limit >>= (blkbits - 9);
2700 		upper_limit <<= blkbits;
2701 	}
2702 
2703 	/*
2704 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2705 	 * by one fs block, so ee_len can cover the extent of maximum file
2706 	 * size
2707 	 */
2708 	res = (1LL << 32) - 1;
2709 	res <<= blkbits;
2710 
2711 	/* Sanity check against vm- & vfs- imposed limits */
2712 	if (res > upper_limit)
2713 		res = upper_limit;
2714 
2715 	return res;
2716 }
2717 
2718 /*
2719  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2720  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2721  * We need to be 1 filesystem block less than the 2^48 sector limit.
2722  */
2723 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2724 {
2725 	loff_t res = EXT4_NDIR_BLOCKS;
2726 	int meta_blocks;
2727 	loff_t upper_limit;
2728 	/* This is calculated to be the largest file size for a dense, block
2729 	 * mapped file such that the file's total number of 512-byte sectors,
2730 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2731 	 *
2732 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2733 	 * number of 512-byte sectors of the file.
2734 	 */
2735 
2736 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2737 		/*
2738 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2739 		 * the inode i_block field represents total file blocks in
2740 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2741 		 */
2742 		upper_limit = (1LL << 32) - 1;
2743 
2744 		/* total blocks in file system block size */
2745 		upper_limit >>= (bits - 9);
2746 
2747 	} else {
2748 		/*
2749 		 * We use 48 bit ext4_inode i_blocks
2750 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2751 		 * represent total number of blocks in
2752 		 * file system block size
2753 		 */
2754 		upper_limit = (1LL << 48) - 1;
2755 
2756 	}
2757 
2758 	/* indirect blocks */
2759 	meta_blocks = 1;
2760 	/* double indirect blocks */
2761 	meta_blocks += 1 + (1LL << (bits-2));
2762 	/* tripple indirect blocks */
2763 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2764 
2765 	upper_limit -= meta_blocks;
2766 	upper_limit <<= bits;
2767 
2768 	res += 1LL << (bits-2);
2769 	res += 1LL << (2*(bits-2));
2770 	res += 1LL << (3*(bits-2));
2771 	res <<= bits;
2772 	if (res > upper_limit)
2773 		res = upper_limit;
2774 
2775 	if (res > MAX_LFS_FILESIZE)
2776 		res = MAX_LFS_FILESIZE;
2777 
2778 	return res;
2779 }
2780 
2781 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2782 				   ext4_fsblk_t logical_sb_block, int nr)
2783 {
2784 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2785 	ext4_group_t bg, first_meta_bg;
2786 	int has_super = 0;
2787 
2788 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2789 
2790 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2791 		return logical_sb_block + nr + 1;
2792 	bg = sbi->s_desc_per_block * nr;
2793 	if (ext4_bg_has_super(sb, bg))
2794 		has_super = 1;
2795 
2796 	/*
2797 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2798 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2799 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2800 	 * compensate.
2801 	 */
2802 	if (sb->s_blocksize == 1024 && nr == 0 &&
2803 	    le32_to_cpu(sbi->s_es->s_first_data_block) == 0)
2804 		has_super++;
2805 
2806 	return (has_super + ext4_group_first_block_no(sb, bg));
2807 }
2808 
2809 /**
2810  * ext4_get_stripe_size: Get the stripe size.
2811  * @sbi: In memory super block info
2812  *
2813  * If we have specified it via mount option, then
2814  * use the mount option value. If the value specified at mount time is
2815  * greater than the blocks per group use the super block value.
2816  * If the super block value is greater than blocks per group return 0.
2817  * Allocator needs it be less than blocks per group.
2818  *
2819  */
2820 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2821 {
2822 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2823 	unsigned long stripe_width =
2824 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2825 	int ret;
2826 
2827 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2828 		ret = sbi->s_stripe;
2829 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2830 		ret = stripe_width;
2831 	else if (stride && stride <= sbi->s_blocks_per_group)
2832 		ret = stride;
2833 	else
2834 		ret = 0;
2835 
2836 	/*
2837 	 * If the stripe width is 1, this makes no sense and
2838 	 * we set it to 0 to turn off stripe handling code.
2839 	 */
2840 	if (ret <= 1)
2841 		ret = 0;
2842 
2843 	return ret;
2844 }
2845 
2846 /*
2847  * Check whether this filesystem can be mounted based on
2848  * the features present and the RDONLY/RDWR mount requested.
2849  * Returns 1 if this filesystem can be mounted as requested,
2850  * 0 if it cannot be.
2851  */
2852 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2853 {
2854 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2855 		ext4_msg(sb, KERN_ERR,
2856 			"Couldn't mount because of "
2857 			"unsupported optional features (%x)",
2858 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2859 			~EXT4_FEATURE_INCOMPAT_SUPP));
2860 		return 0;
2861 	}
2862 
2863 	if (readonly)
2864 		return 1;
2865 
2866 	if (ext4_has_feature_readonly(sb)) {
2867 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2868 		sb->s_flags |= SB_RDONLY;
2869 		return 1;
2870 	}
2871 
2872 	/* Check that feature set is OK for a read-write mount */
2873 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2874 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2875 			 "unsupported optional features (%x)",
2876 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2877 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2878 		return 0;
2879 	}
2880 	/*
2881 	 * Large file size enabled file system can only be mounted
2882 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2883 	 */
2884 	if (ext4_has_feature_huge_file(sb)) {
2885 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2886 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2887 				 "cannot be mounted RDWR without "
2888 				 "CONFIG_LBDAF");
2889 			return 0;
2890 		}
2891 	}
2892 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2893 		ext4_msg(sb, KERN_ERR,
2894 			 "Can't support bigalloc feature without "
2895 			 "extents feature\n");
2896 		return 0;
2897 	}
2898 
2899 #ifndef CONFIG_QUOTA
2900 	if (ext4_has_feature_quota(sb) && !readonly) {
2901 		ext4_msg(sb, KERN_ERR,
2902 			 "Filesystem with quota feature cannot be mounted RDWR "
2903 			 "without CONFIG_QUOTA");
2904 		return 0;
2905 	}
2906 	if (ext4_has_feature_project(sb) && !readonly) {
2907 		ext4_msg(sb, KERN_ERR,
2908 			 "Filesystem with project quota feature cannot be mounted RDWR "
2909 			 "without CONFIG_QUOTA");
2910 		return 0;
2911 	}
2912 #endif  /* CONFIG_QUOTA */
2913 	return 1;
2914 }
2915 
2916 /*
2917  * This function is called once a day if we have errors logged
2918  * on the file system
2919  */
2920 static void print_daily_error_info(struct timer_list *t)
2921 {
2922 	struct ext4_sb_info *sbi = from_timer(sbi, t, s_err_report);
2923 	struct super_block *sb = sbi->s_sb;
2924 	struct ext4_super_block *es = sbi->s_es;
2925 
2926 	if (es->s_error_count)
2927 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2928 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2929 			 le32_to_cpu(es->s_error_count));
2930 	if (es->s_first_error_time) {
2931 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %llu: %.*s:%d",
2932 		       sb->s_id,
2933 		       ext4_get_tstamp(es, s_first_error_time),
2934 		       (int) sizeof(es->s_first_error_func),
2935 		       es->s_first_error_func,
2936 		       le32_to_cpu(es->s_first_error_line));
2937 		if (es->s_first_error_ino)
2938 			printk(KERN_CONT ": inode %u",
2939 			       le32_to_cpu(es->s_first_error_ino));
2940 		if (es->s_first_error_block)
2941 			printk(KERN_CONT ": block %llu", (unsigned long long)
2942 			       le64_to_cpu(es->s_first_error_block));
2943 		printk(KERN_CONT "\n");
2944 	}
2945 	if (es->s_last_error_time) {
2946 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %llu: %.*s:%d",
2947 		       sb->s_id,
2948 		       ext4_get_tstamp(es, s_last_error_time),
2949 		       (int) sizeof(es->s_last_error_func),
2950 		       es->s_last_error_func,
2951 		       le32_to_cpu(es->s_last_error_line));
2952 		if (es->s_last_error_ino)
2953 			printk(KERN_CONT ": inode %u",
2954 			       le32_to_cpu(es->s_last_error_ino));
2955 		if (es->s_last_error_block)
2956 			printk(KERN_CONT ": block %llu", (unsigned long long)
2957 			       le64_to_cpu(es->s_last_error_block));
2958 		printk(KERN_CONT "\n");
2959 	}
2960 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2961 }
2962 
2963 /* Find next suitable group and run ext4_init_inode_table */
2964 static int ext4_run_li_request(struct ext4_li_request *elr)
2965 {
2966 	struct ext4_group_desc *gdp = NULL;
2967 	ext4_group_t group, ngroups;
2968 	struct super_block *sb;
2969 	unsigned long timeout = 0;
2970 	int ret = 0;
2971 
2972 	sb = elr->lr_super;
2973 	ngroups = EXT4_SB(sb)->s_groups_count;
2974 
2975 	for (group = elr->lr_next_group; group < ngroups; group++) {
2976 		gdp = ext4_get_group_desc(sb, group, NULL);
2977 		if (!gdp) {
2978 			ret = 1;
2979 			break;
2980 		}
2981 
2982 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2983 			break;
2984 	}
2985 
2986 	if (group >= ngroups)
2987 		ret = 1;
2988 
2989 	if (!ret) {
2990 		timeout = jiffies;
2991 		ret = ext4_init_inode_table(sb, group,
2992 					    elr->lr_timeout ? 0 : 1);
2993 		if (elr->lr_timeout == 0) {
2994 			timeout = (jiffies - timeout) *
2995 				  elr->lr_sbi->s_li_wait_mult;
2996 			elr->lr_timeout = timeout;
2997 		}
2998 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2999 		elr->lr_next_group = group + 1;
3000 	}
3001 	return ret;
3002 }
3003 
3004 /*
3005  * Remove lr_request from the list_request and free the
3006  * request structure. Should be called with li_list_mtx held
3007  */
3008 static void ext4_remove_li_request(struct ext4_li_request *elr)
3009 {
3010 	struct ext4_sb_info *sbi;
3011 
3012 	if (!elr)
3013 		return;
3014 
3015 	sbi = elr->lr_sbi;
3016 
3017 	list_del(&elr->lr_request);
3018 	sbi->s_li_request = NULL;
3019 	kfree(elr);
3020 }
3021 
3022 static void ext4_unregister_li_request(struct super_block *sb)
3023 {
3024 	mutex_lock(&ext4_li_mtx);
3025 	if (!ext4_li_info) {
3026 		mutex_unlock(&ext4_li_mtx);
3027 		return;
3028 	}
3029 
3030 	mutex_lock(&ext4_li_info->li_list_mtx);
3031 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
3032 	mutex_unlock(&ext4_li_info->li_list_mtx);
3033 	mutex_unlock(&ext4_li_mtx);
3034 }
3035 
3036 static struct task_struct *ext4_lazyinit_task;
3037 
3038 /*
3039  * This is the function where ext4lazyinit thread lives. It walks
3040  * through the request list searching for next scheduled filesystem.
3041  * When such a fs is found, run the lazy initialization request
3042  * (ext4_rn_li_request) and keep track of the time spend in this
3043  * function. Based on that time we compute next schedule time of
3044  * the request. When walking through the list is complete, compute
3045  * next waking time and put itself into sleep.
3046  */
3047 static int ext4_lazyinit_thread(void *arg)
3048 {
3049 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
3050 	struct list_head *pos, *n;
3051 	struct ext4_li_request *elr;
3052 	unsigned long next_wakeup, cur;
3053 
3054 	BUG_ON(NULL == eli);
3055 
3056 cont_thread:
3057 	while (true) {
3058 		next_wakeup = MAX_JIFFY_OFFSET;
3059 
3060 		mutex_lock(&eli->li_list_mtx);
3061 		if (list_empty(&eli->li_request_list)) {
3062 			mutex_unlock(&eli->li_list_mtx);
3063 			goto exit_thread;
3064 		}
3065 		list_for_each_safe(pos, n, &eli->li_request_list) {
3066 			int err = 0;
3067 			int progress = 0;
3068 			elr = list_entry(pos, struct ext4_li_request,
3069 					 lr_request);
3070 
3071 			if (time_before(jiffies, elr->lr_next_sched)) {
3072 				if (time_before(elr->lr_next_sched, next_wakeup))
3073 					next_wakeup = elr->lr_next_sched;
3074 				continue;
3075 			}
3076 			if (down_read_trylock(&elr->lr_super->s_umount)) {
3077 				if (sb_start_write_trylock(elr->lr_super)) {
3078 					progress = 1;
3079 					/*
3080 					 * We hold sb->s_umount, sb can not
3081 					 * be removed from the list, it is
3082 					 * now safe to drop li_list_mtx
3083 					 */
3084 					mutex_unlock(&eli->li_list_mtx);
3085 					err = ext4_run_li_request(elr);
3086 					sb_end_write(elr->lr_super);
3087 					mutex_lock(&eli->li_list_mtx);
3088 					n = pos->next;
3089 				}
3090 				up_read((&elr->lr_super->s_umount));
3091 			}
3092 			/* error, remove the lazy_init job */
3093 			if (err) {
3094 				ext4_remove_li_request(elr);
3095 				continue;
3096 			}
3097 			if (!progress) {
3098 				elr->lr_next_sched = jiffies +
3099 					(prandom_u32()
3100 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
3101 			}
3102 			if (time_before(elr->lr_next_sched, next_wakeup))
3103 				next_wakeup = elr->lr_next_sched;
3104 		}
3105 		mutex_unlock(&eli->li_list_mtx);
3106 
3107 		try_to_freeze();
3108 
3109 		cur = jiffies;
3110 		if ((time_after_eq(cur, next_wakeup)) ||
3111 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
3112 			cond_resched();
3113 			continue;
3114 		}
3115 
3116 		schedule_timeout_interruptible(next_wakeup - cur);
3117 
3118 		if (kthread_should_stop()) {
3119 			ext4_clear_request_list();
3120 			goto exit_thread;
3121 		}
3122 	}
3123 
3124 exit_thread:
3125 	/*
3126 	 * It looks like the request list is empty, but we need
3127 	 * to check it under the li_list_mtx lock, to prevent any
3128 	 * additions into it, and of course we should lock ext4_li_mtx
3129 	 * to atomically free the list and ext4_li_info, because at
3130 	 * this point another ext4 filesystem could be registering
3131 	 * new one.
3132 	 */
3133 	mutex_lock(&ext4_li_mtx);
3134 	mutex_lock(&eli->li_list_mtx);
3135 	if (!list_empty(&eli->li_request_list)) {
3136 		mutex_unlock(&eli->li_list_mtx);
3137 		mutex_unlock(&ext4_li_mtx);
3138 		goto cont_thread;
3139 	}
3140 	mutex_unlock(&eli->li_list_mtx);
3141 	kfree(ext4_li_info);
3142 	ext4_li_info = NULL;
3143 	mutex_unlock(&ext4_li_mtx);
3144 
3145 	return 0;
3146 }
3147 
3148 static void ext4_clear_request_list(void)
3149 {
3150 	struct list_head *pos, *n;
3151 	struct ext4_li_request *elr;
3152 
3153 	mutex_lock(&ext4_li_info->li_list_mtx);
3154 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3155 		elr = list_entry(pos, struct ext4_li_request,
3156 				 lr_request);
3157 		ext4_remove_li_request(elr);
3158 	}
3159 	mutex_unlock(&ext4_li_info->li_list_mtx);
3160 }
3161 
3162 static int ext4_run_lazyinit_thread(void)
3163 {
3164 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3165 					 ext4_li_info, "ext4lazyinit");
3166 	if (IS_ERR(ext4_lazyinit_task)) {
3167 		int err = PTR_ERR(ext4_lazyinit_task);
3168 		ext4_clear_request_list();
3169 		kfree(ext4_li_info);
3170 		ext4_li_info = NULL;
3171 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3172 				 "initialization thread\n",
3173 				 err);
3174 		return err;
3175 	}
3176 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3177 	return 0;
3178 }
3179 
3180 /*
3181  * Check whether it make sense to run itable init. thread or not.
3182  * If there is at least one uninitialized inode table, return
3183  * corresponding group number, else the loop goes through all
3184  * groups and return total number of groups.
3185  */
3186 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3187 {
3188 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3189 	struct ext4_group_desc *gdp = NULL;
3190 
3191 	if (!ext4_has_group_desc_csum(sb))
3192 		return ngroups;
3193 
3194 	for (group = 0; group < ngroups; group++) {
3195 		gdp = ext4_get_group_desc(sb, group, NULL);
3196 		if (!gdp)
3197 			continue;
3198 
3199 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3200 			break;
3201 	}
3202 
3203 	return group;
3204 }
3205 
3206 static int ext4_li_info_new(void)
3207 {
3208 	struct ext4_lazy_init *eli = NULL;
3209 
3210 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3211 	if (!eli)
3212 		return -ENOMEM;
3213 
3214 	INIT_LIST_HEAD(&eli->li_request_list);
3215 	mutex_init(&eli->li_list_mtx);
3216 
3217 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3218 
3219 	ext4_li_info = eli;
3220 
3221 	return 0;
3222 }
3223 
3224 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3225 					    ext4_group_t start)
3226 {
3227 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3228 	struct ext4_li_request *elr;
3229 
3230 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3231 	if (!elr)
3232 		return NULL;
3233 
3234 	elr->lr_super = sb;
3235 	elr->lr_sbi = sbi;
3236 	elr->lr_next_group = start;
3237 
3238 	/*
3239 	 * Randomize first schedule time of the request to
3240 	 * spread the inode table initialization requests
3241 	 * better.
3242 	 */
3243 	elr->lr_next_sched = jiffies + (prandom_u32() %
3244 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3245 	return elr;
3246 }
3247 
3248 int ext4_register_li_request(struct super_block *sb,
3249 			     ext4_group_t first_not_zeroed)
3250 {
3251 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3252 	struct ext4_li_request *elr = NULL;
3253 	ext4_group_t ngroups = sbi->s_groups_count;
3254 	int ret = 0;
3255 
3256 	mutex_lock(&ext4_li_mtx);
3257 	if (sbi->s_li_request != NULL) {
3258 		/*
3259 		 * Reset timeout so it can be computed again, because
3260 		 * s_li_wait_mult might have changed.
3261 		 */
3262 		sbi->s_li_request->lr_timeout = 0;
3263 		goto out;
3264 	}
3265 
3266 	if (first_not_zeroed == ngroups || sb_rdonly(sb) ||
3267 	    !test_opt(sb, INIT_INODE_TABLE))
3268 		goto out;
3269 
3270 	elr = ext4_li_request_new(sb, first_not_zeroed);
3271 	if (!elr) {
3272 		ret = -ENOMEM;
3273 		goto out;
3274 	}
3275 
3276 	if (NULL == ext4_li_info) {
3277 		ret = ext4_li_info_new();
3278 		if (ret)
3279 			goto out;
3280 	}
3281 
3282 	mutex_lock(&ext4_li_info->li_list_mtx);
3283 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3284 	mutex_unlock(&ext4_li_info->li_list_mtx);
3285 
3286 	sbi->s_li_request = elr;
3287 	/*
3288 	 * set elr to NULL here since it has been inserted to
3289 	 * the request_list and the removal and free of it is
3290 	 * handled by ext4_clear_request_list from now on.
3291 	 */
3292 	elr = NULL;
3293 
3294 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3295 		ret = ext4_run_lazyinit_thread();
3296 		if (ret)
3297 			goto out;
3298 	}
3299 out:
3300 	mutex_unlock(&ext4_li_mtx);
3301 	if (ret)
3302 		kfree(elr);
3303 	return ret;
3304 }
3305 
3306 /*
3307  * We do not need to lock anything since this is called on
3308  * module unload.
3309  */
3310 static void ext4_destroy_lazyinit_thread(void)
3311 {
3312 	/*
3313 	 * If thread exited earlier
3314 	 * there's nothing to be done.
3315 	 */
3316 	if (!ext4_li_info || !ext4_lazyinit_task)
3317 		return;
3318 
3319 	kthread_stop(ext4_lazyinit_task);
3320 }
3321 
3322 static int set_journal_csum_feature_set(struct super_block *sb)
3323 {
3324 	int ret = 1;
3325 	int compat, incompat;
3326 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3327 
3328 	if (ext4_has_metadata_csum(sb)) {
3329 		/* journal checksum v3 */
3330 		compat = 0;
3331 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3332 	} else {
3333 		/* journal checksum v1 */
3334 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3335 		incompat = 0;
3336 	}
3337 
3338 	jbd2_journal_clear_features(sbi->s_journal,
3339 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3340 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3341 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3342 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3343 		ret = jbd2_journal_set_features(sbi->s_journal,
3344 				compat, 0,
3345 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3346 				incompat);
3347 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3348 		ret = jbd2_journal_set_features(sbi->s_journal,
3349 				compat, 0,
3350 				incompat);
3351 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3352 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3353 	} else {
3354 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3355 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3356 	}
3357 
3358 	return ret;
3359 }
3360 
3361 /*
3362  * Note: calculating the overhead so we can be compatible with
3363  * historical BSD practice is quite difficult in the face of
3364  * clusters/bigalloc.  This is because multiple metadata blocks from
3365  * different block group can end up in the same allocation cluster.
3366  * Calculating the exact overhead in the face of clustered allocation
3367  * requires either O(all block bitmaps) in memory or O(number of block
3368  * groups**2) in time.  We will still calculate the superblock for
3369  * older file systems --- and if we come across with a bigalloc file
3370  * system with zero in s_overhead_clusters the estimate will be close to
3371  * correct especially for very large cluster sizes --- but for newer
3372  * file systems, it's better to calculate this figure once at mkfs
3373  * time, and store it in the superblock.  If the superblock value is
3374  * present (even for non-bigalloc file systems), we will use it.
3375  */
3376 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3377 			  char *buf)
3378 {
3379 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3380 	struct ext4_group_desc	*gdp;
3381 	ext4_fsblk_t		first_block, last_block, b;
3382 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3383 	int			s, j, count = 0;
3384 
3385 	if (!ext4_has_feature_bigalloc(sb))
3386 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3387 			sbi->s_itb_per_group + 2);
3388 
3389 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3390 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3391 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3392 	for (i = 0; i < ngroups; i++) {
3393 		gdp = ext4_get_group_desc(sb, i, NULL);
3394 		b = ext4_block_bitmap(sb, gdp);
3395 		if (b >= first_block && b <= last_block) {
3396 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3397 			count++;
3398 		}
3399 		b = ext4_inode_bitmap(sb, gdp);
3400 		if (b >= first_block && b <= last_block) {
3401 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3402 			count++;
3403 		}
3404 		b = ext4_inode_table(sb, gdp);
3405 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3406 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3407 				int c = EXT4_B2C(sbi, b - first_block);
3408 				ext4_set_bit(c, buf);
3409 				count++;
3410 			}
3411 		if (i != grp)
3412 			continue;
3413 		s = 0;
3414 		if (ext4_bg_has_super(sb, grp)) {
3415 			ext4_set_bit(s++, buf);
3416 			count++;
3417 		}
3418 		j = ext4_bg_num_gdb(sb, grp);
3419 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3420 			ext4_error(sb, "Invalid number of block group "
3421 				   "descriptor blocks: %d", j);
3422 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3423 		}
3424 		count += j;
3425 		for (; j > 0; j--)
3426 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3427 	}
3428 	if (!count)
3429 		return 0;
3430 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3431 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3432 }
3433 
3434 /*
3435  * Compute the overhead and stash it in sbi->s_overhead
3436  */
3437 int ext4_calculate_overhead(struct super_block *sb)
3438 {
3439 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3440 	struct ext4_super_block *es = sbi->s_es;
3441 	struct inode *j_inode;
3442 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3443 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3444 	ext4_fsblk_t overhead = 0;
3445 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3446 
3447 	if (!buf)
3448 		return -ENOMEM;
3449 
3450 	/*
3451 	 * Compute the overhead (FS structures).  This is constant
3452 	 * for a given filesystem unless the number of block groups
3453 	 * changes so we cache the previous value until it does.
3454 	 */
3455 
3456 	/*
3457 	 * All of the blocks before first_data_block are overhead
3458 	 */
3459 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3460 
3461 	/*
3462 	 * Add the overhead found in each block group
3463 	 */
3464 	for (i = 0; i < ngroups; i++) {
3465 		int blks;
3466 
3467 		blks = count_overhead(sb, i, buf);
3468 		overhead += blks;
3469 		if (blks)
3470 			memset(buf, 0, PAGE_SIZE);
3471 		cond_resched();
3472 	}
3473 
3474 	/*
3475 	 * Add the internal journal blocks whether the journal has been
3476 	 * loaded or not
3477 	 */
3478 	if (sbi->s_journal && !sbi->journal_bdev)
3479 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3480 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3481 		j_inode = ext4_get_journal_inode(sb, j_inum);
3482 		if (j_inode) {
3483 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3484 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3485 			iput(j_inode);
3486 		} else {
3487 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3488 		}
3489 	}
3490 	sbi->s_overhead = overhead;
3491 	smp_wmb();
3492 	free_page((unsigned long) buf);
3493 	return 0;
3494 }
3495 
3496 static void ext4_set_resv_clusters(struct super_block *sb)
3497 {
3498 	ext4_fsblk_t resv_clusters;
3499 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3500 
3501 	/*
3502 	 * There's no need to reserve anything when we aren't using extents.
3503 	 * The space estimates are exact, there are no unwritten extents,
3504 	 * hole punching doesn't need new metadata... This is needed especially
3505 	 * to keep ext2/3 backward compatibility.
3506 	 */
3507 	if (!ext4_has_feature_extents(sb))
3508 		return;
3509 	/*
3510 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3511 	 * This should cover the situations where we can not afford to run
3512 	 * out of space like for example punch hole, or converting
3513 	 * unwritten extents in delalloc path. In most cases such
3514 	 * allocation would require 1, or 2 blocks, higher numbers are
3515 	 * very rare.
3516 	 */
3517 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3518 			 sbi->s_cluster_bits);
3519 
3520 	do_div(resv_clusters, 50);
3521 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3522 
3523 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3524 }
3525 
3526 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3527 {
3528 	struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev);
3529 	char *orig_data = kstrdup(data, GFP_KERNEL);
3530 	struct buffer_head *bh;
3531 	struct ext4_super_block *es = NULL;
3532 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3533 	ext4_fsblk_t block;
3534 	ext4_fsblk_t sb_block = get_sb_block(&data);
3535 	ext4_fsblk_t logical_sb_block;
3536 	unsigned long offset = 0;
3537 	unsigned long journal_devnum = 0;
3538 	unsigned long def_mount_opts;
3539 	struct inode *root;
3540 	const char *descr;
3541 	int ret = -ENOMEM;
3542 	int blocksize, clustersize;
3543 	unsigned int db_count;
3544 	unsigned int i;
3545 	int needs_recovery, has_huge_files, has_bigalloc;
3546 	__u64 blocks_count;
3547 	int err = 0;
3548 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3549 	ext4_group_t first_not_zeroed;
3550 
3551 	if ((data && !orig_data) || !sbi)
3552 		goto out_free_base;
3553 
3554 	sbi->s_daxdev = dax_dev;
3555 	sbi->s_blockgroup_lock =
3556 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3557 	if (!sbi->s_blockgroup_lock)
3558 		goto out_free_base;
3559 
3560 	sb->s_fs_info = sbi;
3561 	sbi->s_sb = sb;
3562 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3563 	sbi->s_sb_block = sb_block;
3564 	if (sb->s_bdev->bd_part)
3565 		sbi->s_sectors_written_start =
3566 			part_stat_read(sb->s_bdev->bd_part, sectors[STAT_WRITE]);
3567 
3568 	/* Cleanup superblock name */
3569 	strreplace(sb->s_id, '/', '!');
3570 
3571 	/* -EINVAL is default */
3572 	ret = -EINVAL;
3573 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3574 	if (!blocksize) {
3575 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3576 		goto out_fail;
3577 	}
3578 
3579 	/*
3580 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3581 	 * block sizes.  We need to calculate the offset from buffer start.
3582 	 */
3583 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3584 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3585 		offset = do_div(logical_sb_block, blocksize);
3586 	} else {
3587 		logical_sb_block = sb_block;
3588 	}
3589 
3590 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3591 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3592 		goto out_fail;
3593 	}
3594 	/*
3595 	 * Note: s_es must be initialized as soon as possible because
3596 	 *       some ext4 macro-instructions depend on its value
3597 	 */
3598 	es = (struct ext4_super_block *) (bh->b_data + offset);
3599 	sbi->s_es = es;
3600 	sb->s_magic = le16_to_cpu(es->s_magic);
3601 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3602 		goto cantfind_ext4;
3603 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3604 
3605 	/* Warn if metadata_csum and gdt_csum are both set. */
3606 	if (ext4_has_feature_metadata_csum(sb) &&
3607 	    ext4_has_feature_gdt_csum(sb))
3608 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3609 			     "redundant flags; please run fsck.");
3610 
3611 	/* Check for a known checksum algorithm */
3612 	if (!ext4_verify_csum_type(sb, es)) {
3613 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3614 			 "unknown checksum algorithm.");
3615 		silent = 1;
3616 		goto cantfind_ext4;
3617 	}
3618 
3619 	/* Load the checksum driver */
3620 	sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3621 	if (IS_ERR(sbi->s_chksum_driver)) {
3622 		ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3623 		ret = PTR_ERR(sbi->s_chksum_driver);
3624 		sbi->s_chksum_driver = NULL;
3625 		goto failed_mount;
3626 	}
3627 
3628 	/* Check superblock checksum */
3629 	if (!ext4_superblock_csum_verify(sb, es)) {
3630 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3631 			 "invalid superblock checksum.  Run e2fsck?");
3632 		silent = 1;
3633 		ret = -EFSBADCRC;
3634 		goto cantfind_ext4;
3635 	}
3636 
3637 	/* Precompute checksum seed for all metadata */
3638 	if (ext4_has_feature_csum_seed(sb))
3639 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3640 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3641 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3642 					       sizeof(es->s_uuid));
3643 
3644 	/* Set defaults before we parse the mount options */
3645 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3646 	set_opt(sb, INIT_INODE_TABLE);
3647 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3648 		set_opt(sb, DEBUG);
3649 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3650 		set_opt(sb, GRPID);
3651 	if (def_mount_opts & EXT4_DEFM_UID16)
3652 		set_opt(sb, NO_UID32);
3653 	/* xattr user namespace & acls are now defaulted on */
3654 	set_opt(sb, XATTR_USER);
3655 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3656 	set_opt(sb, POSIX_ACL);
3657 #endif
3658 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3659 	if (ext4_has_metadata_csum(sb))
3660 		set_opt(sb, JOURNAL_CHECKSUM);
3661 
3662 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3663 		set_opt(sb, JOURNAL_DATA);
3664 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3665 		set_opt(sb, ORDERED_DATA);
3666 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3667 		set_opt(sb, WRITEBACK_DATA);
3668 
3669 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3670 		set_opt(sb, ERRORS_PANIC);
3671 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3672 		set_opt(sb, ERRORS_CONT);
3673 	else
3674 		set_opt(sb, ERRORS_RO);
3675 	/* block_validity enabled by default; disable with noblock_validity */
3676 	set_opt(sb, BLOCK_VALIDITY);
3677 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3678 		set_opt(sb, DISCARD);
3679 
3680 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3681 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3682 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3683 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3684 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3685 
3686 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3687 		set_opt(sb, BARRIER);
3688 
3689 	/*
3690 	 * enable delayed allocation by default
3691 	 * Use -o nodelalloc to turn it off
3692 	 */
3693 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3694 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3695 		set_opt(sb, DELALLOC);
3696 
3697 	/*
3698 	 * set default s_li_wait_mult for lazyinit, for the case there is
3699 	 * no mount option specified.
3700 	 */
3701 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3702 
3703 	if (sbi->s_es->s_mount_opts[0]) {
3704 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3705 					      sizeof(sbi->s_es->s_mount_opts),
3706 					      GFP_KERNEL);
3707 		if (!s_mount_opts)
3708 			goto failed_mount;
3709 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3710 				   &journal_ioprio, 0)) {
3711 			ext4_msg(sb, KERN_WARNING,
3712 				 "failed to parse options in superblock: %s",
3713 				 s_mount_opts);
3714 		}
3715 		kfree(s_mount_opts);
3716 	}
3717 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3718 	if (!parse_options((char *) data, sb, &journal_devnum,
3719 			   &journal_ioprio, 0))
3720 		goto failed_mount;
3721 
3722 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3723 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3724 			    "with data=journal disables delayed "
3725 			    "allocation and O_DIRECT support!\n");
3726 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3727 			ext4_msg(sb, KERN_ERR, "can't mount with "
3728 				 "both data=journal and delalloc");
3729 			goto failed_mount;
3730 		}
3731 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3732 			ext4_msg(sb, KERN_ERR, "can't mount with "
3733 				 "both data=journal and dioread_nolock");
3734 			goto failed_mount;
3735 		}
3736 		if (test_opt(sb, DAX)) {
3737 			ext4_msg(sb, KERN_ERR, "can't mount with "
3738 				 "both data=journal and dax");
3739 			goto failed_mount;
3740 		}
3741 		if (ext4_has_feature_encrypt(sb)) {
3742 			ext4_msg(sb, KERN_WARNING,
3743 				 "encrypted files will use data=ordered "
3744 				 "instead of data journaling mode");
3745 		}
3746 		if (test_opt(sb, DELALLOC))
3747 			clear_opt(sb, DELALLOC);
3748 	} else {
3749 		sb->s_iflags |= SB_I_CGROUPWB;
3750 	}
3751 
3752 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
3753 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
3754 
3755 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3756 	    (ext4_has_compat_features(sb) ||
3757 	     ext4_has_ro_compat_features(sb) ||
3758 	     ext4_has_incompat_features(sb)))
3759 		ext4_msg(sb, KERN_WARNING,
3760 		       "feature flags set on rev 0 fs, "
3761 		       "running e2fsck is recommended");
3762 
3763 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3764 		set_opt2(sb, HURD_COMPAT);
3765 		if (ext4_has_feature_64bit(sb)) {
3766 			ext4_msg(sb, KERN_ERR,
3767 				 "The Hurd can't support 64-bit file systems");
3768 			goto failed_mount;
3769 		}
3770 
3771 		/*
3772 		 * ea_inode feature uses l_i_version field which is not
3773 		 * available in HURD_COMPAT mode.
3774 		 */
3775 		if (ext4_has_feature_ea_inode(sb)) {
3776 			ext4_msg(sb, KERN_ERR,
3777 				 "ea_inode feature is not supported for Hurd");
3778 			goto failed_mount;
3779 		}
3780 	}
3781 
3782 	if (IS_EXT2_SB(sb)) {
3783 		if (ext2_feature_set_ok(sb))
3784 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3785 				 "using the ext4 subsystem");
3786 		else {
3787 			/*
3788 			 * If we're probing be silent, if this looks like
3789 			 * it's actually an ext[34] filesystem.
3790 			 */
3791 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3792 				goto failed_mount;
3793 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3794 				 "to feature incompatibilities");
3795 			goto failed_mount;
3796 		}
3797 	}
3798 
3799 	if (IS_EXT3_SB(sb)) {
3800 		if (ext3_feature_set_ok(sb))
3801 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3802 				 "using the ext4 subsystem");
3803 		else {
3804 			/*
3805 			 * If we're probing be silent, if this looks like
3806 			 * it's actually an ext4 filesystem.
3807 			 */
3808 			if (silent && ext4_feature_set_ok(sb, sb_rdonly(sb)))
3809 				goto failed_mount;
3810 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3811 				 "to feature incompatibilities");
3812 			goto failed_mount;
3813 		}
3814 	}
3815 
3816 	/*
3817 	 * Check feature flags regardless of the revision level, since we
3818 	 * previously didn't change the revision level when setting the flags,
3819 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3820 	 */
3821 	if (!ext4_feature_set_ok(sb, (sb_rdonly(sb))))
3822 		goto failed_mount;
3823 
3824 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3825 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3826 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3827 		ext4_msg(sb, KERN_ERR,
3828 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3829 			 blocksize, le32_to_cpu(es->s_log_block_size));
3830 		goto failed_mount;
3831 	}
3832 	if (le32_to_cpu(es->s_log_block_size) >
3833 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3834 		ext4_msg(sb, KERN_ERR,
3835 			 "Invalid log block size: %u",
3836 			 le32_to_cpu(es->s_log_block_size));
3837 		goto failed_mount;
3838 	}
3839 	if (le32_to_cpu(es->s_log_cluster_size) >
3840 	    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3841 		ext4_msg(sb, KERN_ERR,
3842 			 "Invalid log cluster size: %u",
3843 			 le32_to_cpu(es->s_log_cluster_size));
3844 		goto failed_mount;
3845 	}
3846 
3847 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3848 		ext4_msg(sb, KERN_ERR,
3849 			 "Number of reserved GDT blocks insanely large: %d",
3850 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3851 		goto failed_mount;
3852 	}
3853 
3854 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3855 		if (ext4_has_feature_inline_data(sb)) {
3856 			ext4_msg(sb, KERN_ERR, "Cannot use DAX on a filesystem"
3857 					" that may contain inline data");
3858 			goto failed_mount;
3859 		}
3860 		if (!bdev_dax_supported(sb->s_bdev, blocksize)) {
3861 			ext4_msg(sb, KERN_ERR,
3862 				"DAX unsupported by block device.");
3863 			goto failed_mount;
3864 		}
3865 	}
3866 
3867 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3868 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3869 			 es->s_encryption_level);
3870 		goto failed_mount;
3871 	}
3872 
3873 	if (sb->s_blocksize != blocksize) {
3874 		/* Validate the filesystem blocksize */
3875 		if (!sb_set_blocksize(sb, blocksize)) {
3876 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3877 					blocksize);
3878 			goto failed_mount;
3879 		}
3880 
3881 		brelse(bh);
3882 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3883 		offset = do_div(logical_sb_block, blocksize);
3884 		bh = sb_bread_unmovable(sb, logical_sb_block);
3885 		if (!bh) {
3886 			ext4_msg(sb, KERN_ERR,
3887 			       "Can't read superblock on 2nd try");
3888 			goto failed_mount;
3889 		}
3890 		es = (struct ext4_super_block *)(bh->b_data + offset);
3891 		sbi->s_es = es;
3892 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3893 			ext4_msg(sb, KERN_ERR,
3894 			       "Magic mismatch, very weird!");
3895 			goto failed_mount;
3896 		}
3897 	}
3898 
3899 	has_huge_files = ext4_has_feature_huge_file(sb);
3900 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3901 						      has_huge_files);
3902 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3903 
3904 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3905 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3906 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3907 	} else {
3908 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3909 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3910 		if (sbi->s_first_ino < EXT4_GOOD_OLD_FIRST_INO) {
3911 			ext4_msg(sb, KERN_ERR, "invalid first ino: %u",
3912 				 sbi->s_first_ino);
3913 			goto failed_mount;
3914 		}
3915 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3916 		    (!is_power_of_2(sbi->s_inode_size)) ||
3917 		    (sbi->s_inode_size > blocksize)) {
3918 			ext4_msg(sb, KERN_ERR,
3919 			       "unsupported inode size: %d",
3920 			       sbi->s_inode_size);
3921 			goto failed_mount;
3922 		}
3923 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3924 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3925 	}
3926 
3927 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3928 	if (ext4_has_feature_64bit(sb)) {
3929 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3930 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3931 		    !is_power_of_2(sbi->s_desc_size)) {
3932 			ext4_msg(sb, KERN_ERR,
3933 			       "unsupported descriptor size %lu",
3934 			       sbi->s_desc_size);
3935 			goto failed_mount;
3936 		}
3937 	} else
3938 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3939 
3940 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3941 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3942 
3943 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3944 	if (sbi->s_inodes_per_block == 0)
3945 		goto cantfind_ext4;
3946 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3947 	    sbi->s_inodes_per_group > blocksize * 8) {
3948 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3949 			 sbi->s_blocks_per_group);
3950 		goto failed_mount;
3951 	}
3952 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3953 					sbi->s_inodes_per_block;
3954 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3955 	sbi->s_sbh = bh;
3956 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3957 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3958 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3959 
3960 	for (i = 0; i < 4; i++)
3961 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3962 	sbi->s_def_hash_version = es->s_def_hash_version;
3963 	if (ext4_has_feature_dir_index(sb)) {
3964 		i = le32_to_cpu(es->s_flags);
3965 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3966 			sbi->s_hash_unsigned = 3;
3967 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3968 #ifdef __CHAR_UNSIGNED__
3969 			if (!sb_rdonly(sb))
3970 				es->s_flags |=
3971 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3972 			sbi->s_hash_unsigned = 3;
3973 #else
3974 			if (!sb_rdonly(sb))
3975 				es->s_flags |=
3976 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3977 #endif
3978 		}
3979 	}
3980 
3981 	/* Handle clustersize */
3982 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3983 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3984 	if (has_bigalloc) {
3985 		if (clustersize < blocksize) {
3986 			ext4_msg(sb, KERN_ERR,
3987 				 "cluster size (%d) smaller than "
3988 				 "block size (%d)", clustersize, blocksize);
3989 			goto failed_mount;
3990 		}
3991 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3992 			le32_to_cpu(es->s_log_block_size);
3993 		sbi->s_clusters_per_group =
3994 			le32_to_cpu(es->s_clusters_per_group);
3995 		if (sbi->s_clusters_per_group > blocksize * 8) {
3996 			ext4_msg(sb, KERN_ERR,
3997 				 "#clusters per group too big: %lu",
3998 				 sbi->s_clusters_per_group);
3999 			goto failed_mount;
4000 		}
4001 		if (sbi->s_blocks_per_group !=
4002 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
4003 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
4004 				 "clusters per group (%lu) inconsistent",
4005 				 sbi->s_blocks_per_group,
4006 				 sbi->s_clusters_per_group);
4007 			goto failed_mount;
4008 		}
4009 	} else {
4010 		if (clustersize != blocksize) {
4011 			ext4_msg(sb, KERN_ERR,
4012 				 "fragment/cluster size (%d) != "
4013 				 "block size (%d)", clustersize, blocksize);
4014 			goto failed_mount;
4015 		}
4016 		if (sbi->s_blocks_per_group > blocksize * 8) {
4017 			ext4_msg(sb, KERN_ERR,
4018 				 "#blocks per group too big: %lu",
4019 				 sbi->s_blocks_per_group);
4020 			goto failed_mount;
4021 		}
4022 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
4023 		sbi->s_cluster_bits = 0;
4024 	}
4025 	sbi->s_cluster_ratio = clustersize / blocksize;
4026 
4027 	/* Do we have standard group size of clustersize * 8 blocks ? */
4028 	if (sbi->s_blocks_per_group == clustersize << 3)
4029 		set_opt2(sb, STD_GROUP_SIZE);
4030 
4031 	/*
4032 	 * Test whether we have more sectors than will fit in sector_t,
4033 	 * and whether the max offset is addressable by the page cache.
4034 	 */
4035 	err = generic_check_addressable(sb->s_blocksize_bits,
4036 					ext4_blocks_count(es));
4037 	if (err) {
4038 		ext4_msg(sb, KERN_ERR, "filesystem"
4039 			 " too large to mount safely on this system");
4040 		if (sizeof(sector_t) < 8)
4041 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
4042 		goto failed_mount;
4043 	}
4044 
4045 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
4046 		goto cantfind_ext4;
4047 
4048 	/* check blocks count against device size */
4049 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
4050 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
4051 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
4052 		       "exceeds size of device (%llu blocks)",
4053 		       ext4_blocks_count(es), blocks_count);
4054 		goto failed_mount;
4055 	}
4056 
4057 	/*
4058 	 * It makes no sense for the first data block to be beyond the end
4059 	 * of the filesystem.
4060 	 */
4061 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
4062 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4063 			 "block %u is beyond end of filesystem (%llu)",
4064 			 le32_to_cpu(es->s_first_data_block),
4065 			 ext4_blocks_count(es));
4066 		goto failed_mount;
4067 	}
4068 	if ((es->s_first_data_block == 0) && (es->s_log_block_size == 0) &&
4069 	    (sbi->s_cluster_ratio == 1)) {
4070 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
4071 			 "block is 0 with a 1k block and cluster size");
4072 		goto failed_mount;
4073 	}
4074 
4075 	blocks_count = (ext4_blocks_count(es) -
4076 			le32_to_cpu(es->s_first_data_block) +
4077 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
4078 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
4079 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
4080 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
4081 		       "(block count %llu, first data block %u, "
4082 		       "blocks per group %lu)", sbi->s_groups_count,
4083 		       ext4_blocks_count(es),
4084 		       le32_to_cpu(es->s_first_data_block),
4085 		       EXT4_BLOCKS_PER_GROUP(sb));
4086 		goto failed_mount;
4087 	}
4088 	sbi->s_groups_count = blocks_count;
4089 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
4090 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
4091 	if (((u64)sbi->s_groups_count * sbi->s_inodes_per_group) !=
4092 	    le32_to_cpu(es->s_inodes_count)) {
4093 		ext4_msg(sb, KERN_ERR, "inodes count not valid: %u vs %llu",
4094 			 le32_to_cpu(es->s_inodes_count),
4095 			 ((u64)sbi->s_groups_count * sbi->s_inodes_per_group));
4096 		ret = -EINVAL;
4097 		goto failed_mount;
4098 	}
4099 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
4100 		   EXT4_DESC_PER_BLOCK(sb);
4101 	if (ext4_has_feature_meta_bg(sb)) {
4102 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
4103 			ext4_msg(sb, KERN_WARNING,
4104 				 "first meta block group too large: %u "
4105 				 "(group descriptor block count %u)",
4106 				 le32_to_cpu(es->s_first_meta_bg), db_count);
4107 			goto failed_mount;
4108 		}
4109 	}
4110 	sbi->s_group_desc = kvmalloc_array(db_count,
4111 					   sizeof(struct buffer_head *),
4112 					   GFP_KERNEL);
4113 	if (sbi->s_group_desc == NULL) {
4114 		ext4_msg(sb, KERN_ERR, "not enough memory");
4115 		ret = -ENOMEM;
4116 		goto failed_mount;
4117 	}
4118 
4119 	bgl_lock_init(sbi->s_blockgroup_lock);
4120 
4121 	/* Pre-read the descriptors into the buffer cache */
4122 	for (i = 0; i < db_count; i++) {
4123 		block = descriptor_loc(sb, logical_sb_block, i);
4124 		sb_breadahead(sb, block);
4125 	}
4126 
4127 	for (i = 0; i < db_count; i++) {
4128 		block = descriptor_loc(sb, logical_sb_block, i);
4129 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
4130 		if (!sbi->s_group_desc[i]) {
4131 			ext4_msg(sb, KERN_ERR,
4132 			       "can't read group descriptor %d", i);
4133 			db_count = i;
4134 			goto failed_mount2;
4135 		}
4136 	}
4137 	sbi->s_gdb_count = db_count;
4138 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
4139 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
4140 		ret = -EFSCORRUPTED;
4141 		goto failed_mount2;
4142 	}
4143 
4144 	timer_setup(&sbi->s_err_report, print_daily_error_info, 0);
4145 
4146 	/* Register extent status tree shrinker */
4147 	if (ext4_es_register_shrinker(sbi))
4148 		goto failed_mount3;
4149 
4150 	sbi->s_stripe = ext4_get_stripe_size(sbi);
4151 	sbi->s_extent_max_zeroout_kb = 32;
4152 
4153 	/*
4154 	 * set up enough so that it can read an inode
4155 	 */
4156 	sb->s_op = &ext4_sops;
4157 	sb->s_export_op = &ext4_export_ops;
4158 	sb->s_xattr = ext4_xattr_handlers;
4159 #ifdef CONFIG_EXT4_FS_ENCRYPTION
4160 	sb->s_cop = &ext4_cryptops;
4161 #endif
4162 #ifdef CONFIG_QUOTA
4163 	sb->dq_op = &ext4_quota_operations;
4164 	if (ext4_has_feature_quota(sb))
4165 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4166 	else
4167 		sb->s_qcop = &ext4_qctl_operations;
4168 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4169 #endif
4170 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4171 
4172 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4173 	mutex_init(&sbi->s_orphan_lock);
4174 
4175 	sb->s_root = NULL;
4176 
4177 	needs_recovery = (es->s_last_orphan != 0 ||
4178 			  ext4_has_feature_journal_needs_recovery(sb));
4179 
4180 	if (ext4_has_feature_mmp(sb) && !sb_rdonly(sb))
4181 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4182 			goto failed_mount3a;
4183 
4184 	/*
4185 	 * The first inode we look at is the journal inode.  Don't try
4186 	 * root first: it may be modified in the journal!
4187 	 */
4188 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4189 		err = ext4_load_journal(sb, es, journal_devnum);
4190 		if (err)
4191 			goto failed_mount3a;
4192 	} else if (test_opt(sb, NOLOAD) && !sb_rdonly(sb) &&
4193 		   ext4_has_feature_journal_needs_recovery(sb)) {
4194 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4195 		       "suppressed and not mounted read-only");
4196 		goto failed_mount_wq;
4197 	} else {
4198 		/* Nojournal mode, all journal mount options are illegal */
4199 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4200 			ext4_msg(sb, KERN_ERR, "can't mount with "
4201 				 "journal_checksum, fs mounted w/o journal");
4202 			goto failed_mount_wq;
4203 		}
4204 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4205 			ext4_msg(sb, KERN_ERR, "can't mount with "
4206 				 "journal_async_commit, fs mounted w/o journal");
4207 			goto failed_mount_wq;
4208 		}
4209 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4210 			ext4_msg(sb, KERN_ERR, "can't mount with "
4211 				 "commit=%lu, fs mounted w/o journal",
4212 				 sbi->s_commit_interval / HZ);
4213 			goto failed_mount_wq;
4214 		}
4215 		if (EXT4_MOUNT_DATA_FLAGS &
4216 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4217 			ext4_msg(sb, KERN_ERR, "can't mount with "
4218 				 "data=, fs mounted w/o journal");
4219 			goto failed_mount_wq;
4220 		}
4221 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4222 		clear_opt(sb, JOURNAL_CHECKSUM);
4223 		clear_opt(sb, DATA_FLAGS);
4224 		sbi->s_journal = NULL;
4225 		needs_recovery = 0;
4226 		goto no_journal;
4227 	}
4228 
4229 	if (ext4_has_feature_64bit(sb) &&
4230 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4231 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4232 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4233 		goto failed_mount_wq;
4234 	}
4235 
4236 	if (!set_journal_csum_feature_set(sb)) {
4237 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4238 			 "feature set");
4239 		goto failed_mount_wq;
4240 	}
4241 
4242 	/* We have now updated the journal if required, so we can
4243 	 * validate the data journaling mode. */
4244 	switch (test_opt(sb, DATA_FLAGS)) {
4245 	case 0:
4246 		/* No mode set, assume a default based on the journal
4247 		 * capabilities: ORDERED_DATA if the journal can
4248 		 * cope, else JOURNAL_DATA
4249 		 */
4250 		if (jbd2_journal_check_available_features
4251 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4252 			set_opt(sb, ORDERED_DATA);
4253 			sbi->s_def_mount_opt |= EXT4_MOUNT_ORDERED_DATA;
4254 		} else {
4255 			set_opt(sb, JOURNAL_DATA);
4256 			sbi->s_def_mount_opt |= EXT4_MOUNT_JOURNAL_DATA;
4257 		}
4258 		break;
4259 
4260 	case EXT4_MOUNT_ORDERED_DATA:
4261 	case EXT4_MOUNT_WRITEBACK_DATA:
4262 		if (!jbd2_journal_check_available_features
4263 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4264 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4265 			       "requested data journaling mode");
4266 			goto failed_mount_wq;
4267 		}
4268 	default:
4269 		break;
4270 	}
4271 
4272 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4273 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4274 		ext4_msg(sb, KERN_ERR, "can't mount with "
4275 			"journal_async_commit in data=ordered mode");
4276 		goto failed_mount_wq;
4277 	}
4278 
4279 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4280 
4281 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4282 
4283 no_journal:
4284 	if (!test_opt(sb, NO_MBCACHE)) {
4285 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4286 		if (!sbi->s_ea_block_cache) {
4287 			ext4_msg(sb, KERN_ERR,
4288 				 "Failed to create ea_block_cache");
4289 			goto failed_mount_wq;
4290 		}
4291 
4292 		if (ext4_has_feature_ea_inode(sb)) {
4293 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4294 			if (!sbi->s_ea_inode_cache) {
4295 				ext4_msg(sb, KERN_ERR,
4296 					 "Failed to create ea_inode_cache");
4297 				goto failed_mount_wq;
4298 			}
4299 		}
4300 	}
4301 
4302 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4303 	    (blocksize != PAGE_SIZE)) {
4304 		ext4_msg(sb, KERN_ERR,
4305 			 "Unsupported blocksize for fs encryption");
4306 		goto failed_mount_wq;
4307 	}
4308 
4309 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !sb_rdonly(sb) &&
4310 	    !ext4_has_feature_encrypt(sb)) {
4311 		ext4_set_feature_encrypt(sb);
4312 		ext4_commit_super(sb, 1);
4313 	}
4314 
4315 	/*
4316 	 * Get the # of file system overhead blocks from the
4317 	 * superblock if present.
4318 	 */
4319 	if (es->s_overhead_clusters)
4320 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4321 	else {
4322 		err = ext4_calculate_overhead(sb);
4323 		if (err)
4324 			goto failed_mount_wq;
4325 	}
4326 
4327 	/*
4328 	 * The maximum number of concurrent works can be high and
4329 	 * concurrency isn't really necessary.  Limit it to 1.
4330 	 */
4331 	EXT4_SB(sb)->rsv_conversion_wq =
4332 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4333 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4334 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4335 		ret = -ENOMEM;
4336 		goto failed_mount4;
4337 	}
4338 
4339 	/*
4340 	 * The jbd2_journal_load will have done any necessary log recovery,
4341 	 * so we can safely mount the rest of the filesystem now.
4342 	 */
4343 
4344 	root = ext4_iget(sb, EXT4_ROOT_INO, EXT4_IGET_SPECIAL);
4345 	if (IS_ERR(root)) {
4346 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4347 		ret = PTR_ERR(root);
4348 		root = NULL;
4349 		goto failed_mount4;
4350 	}
4351 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4352 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4353 		iput(root);
4354 		goto failed_mount4;
4355 	}
4356 	sb->s_root = d_make_root(root);
4357 	if (!sb->s_root) {
4358 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4359 		ret = -ENOMEM;
4360 		goto failed_mount4;
4361 	}
4362 
4363 	ret = ext4_setup_super(sb, es, sb_rdonly(sb));
4364 	if (ret == -EROFS) {
4365 		sb->s_flags |= SB_RDONLY;
4366 		ret = 0;
4367 	} else if (ret)
4368 		goto failed_mount4a;
4369 
4370 	/* determine the minimum size of new large inodes, if present */
4371 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4372 	    sbi->s_want_extra_isize == 0) {
4373 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4374 						     EXT4_GOOD_OLD_INODE_SIZE;
4375 		if (ext4_has_feature_extra_isize(sb)) {
4376 			if (sbi->s_want_extra_isize <
4377 			    le16_to_cpu(es->s_want_extra_isize))
4378 				sbi->s_want_extra_isize =
4379 					le16_to_cpu(es->s_want_extra_isize);
4380 			if (sbi->s_want_extra_isize <
4381 			    le16_to_cpu(es->s_min_extra_isize))
4382 				sbi->s_want_extra_isize =
4383 					le16_to_cpu(es->s_min_extra_isize);
4384 		}
4385 	}
4386 	/* Check if enough inode space is available */
4387 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4388 							sbi->s_inode_size) {
4389 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4390 						       EXT4_GOOD_OLD_INODE_SIZE;
4391 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4392 			 "available");
4393 	}
4394 
4395 	ext4_set_resv_clusters(sb);
4396 
4397 	err = ext4_setup_system_zone(sb);
4398 	if (err) {
4399 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4400 			 "zone (%d)", err);
4401 		goto failed_mount4a;
4402 	}
4403 
4404 	ext4_ext_init(sb);
4405 	err = ext4_mb_init(sb);
4406 	if (err) {
4407 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4408 			 err);
4409 		goto failed_mount5;
4410 	}
4411 
4412 	block = ext4_count_free_clusters(sb);
4413 	ext4_free_blocks_count_set(sbi->s_es,
4414 				   EXT4_C2B(sbi, block));
4415 	ext4_superblock_csum_set(sb);
4416 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4417 				  GFP_KERNEL);
4418 	if (!err) {
4419 		unsigned long freei = ext4_count_free_inodes(sb);
4420 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4421 		ext4_superblock_csum_set(sb);
4422 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4423 					  GFP_KERNEL);
4424 	}
4425 	if (!err)
4426 		err = percpu_counter_init(&sbi->s_dirs_counter,
4427 					  ext4_count_dirs(sb), GFP_KERNEL);
4428 	if (!err)
4429 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4430 					  GFP_KERNEL);
4431 	if (!err)
4432 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4433 
4434 	if (err) {
4435 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4436 		goto failed_mount6;
4437 	}
4438 
4439 	if (ext4_has_feature_flex_bg(sb))
4440 		if (!ext4_fill_flex_info(sb)) {
4441 			ext4_msg(sb, KERN_ERR,
4442 			       "unable to initialize "
4443 			       "flex_bg meta info!");
4444 			goto failed_mount6;
4445 		}
4446 
4447 	err = ext4_register_li_request(sb, first_not_zeroed);
4448 	if (err)
4449 		goto failed_mount6;
4450 
4451 	err = ext4_register_sysfs(sb);
4452 	if (err)
4453 		goto failed_mount7;
4454 
4455 #ifdef CONFIG_QUOTA
4456 	/* Enable quota usage during mount. */
4457 	if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) {
4458 		err = ext4_enable_quotas(sb);
4459 		if (err)
4460 			goto failed_mount8;
4461 	}
4462 #endif  /* CONFIG_QUOTA */
4463 
4464 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4465 	ext4_orphan_cleanup(sb, es);
4466 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4467 	if (needs_recovery) {
4468 		ext4_msg(sb, KERN_INFO, "recovery complete");
4469 		ext4_mark_recovery_complete(sb, es);
4470 	}
4471 	if (EXT4_SB(sb)->s_journal) {
4472 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4473 			descr = " journalled data mode";
4474 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4475 			descr = " ordered data mode";
4476 		else
4477 			descr = " writeback data mode";
4478 	} else
4479 		descr = "out journal";
4480 
4481 	if (test_opt(sb, DISCARD)) {
4482 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4483 		if (!blk_queue_discard(q))
4484 			ext4_msg(sb, KERN_WARNING,
4485 				 "mounting with \"discard\" option, but "
4486 				 "the device does not support discard");
4487 	}
4488 
4489 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4490 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4491 			 "Opts: %.*s%s%s", descr,
4492 			 (int) sizeof(sbi->s_es->s_mount_opts),
4493 			 sbi->s_es->s_mount_opts,
4494 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4495 
4496 	if (es->s_error_count)
4497 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4498 
4499 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4500 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4501 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4502 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4503 
4504 	kfree(orig_data);
4505 	return 0;
4506 
4507 cantfind_ext4:
4508 	if (!silent)
4509 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4510 	goto failed_mount;
4511 
4512 #ifdef CONFIG_QUOTA
4513 failed_mount8:
4514 	ext4_unregister_sysfs(sb);
4515 #endif
4516 failed_mount7:
4517 	ext4_unregister_li_request(sb);
4518 failed_mount6:
4519 	ext4_mb_release(sb);
4520 	if (sbi->s_flex_groups)
4521 		kvfree(sbi->s_flex_groups);
4522 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4523 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4524 	percpu_counter_destroy(&sbi->s_dirs_counter);
4525 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4526 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
4527 failed_mount5:
4528 	ext4_ext_release(sb);
4529 	ext4_release_system_zone(sb);
4530 failed_mount4a:
4531 	dput(sb->s_root);
4532 	sb->s_root = NULL;
4533 failed_mount4:
4534 	ext4_msg(sb, KERN_ERR, "mount failed");
4535 	if (EXT4_SB(sb)->rsv_conversion_wq)
4536 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4537 failed_mount_wq:
4538 	ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4539 	sbi->s_ea_inode_cache = NULL;
4540 
4541 	ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4542 	sbi->s_ea_block_cache = NULL;
4543 
4544 	if (sbi->s_journal) {
4545 		jbd2_journal_destroy(sbi->s_journal);
4546 		sbi->s_journal = NULL;
4547 	}
4548 failed_mount3a:
4549 	ext4_es_unregister_shrinker(sbi);
4550 failed_mount3:
4551 	del_timer_sync(&sbi->s_err_report);
4552 	if (sbi->s_mmp_tsk)
4553 		kthread_stop(sbi->s_mmp_tsk);
4554 failed_mount2:
4555 	for (i = 0; i < db_count; i++)
4556 		brelse(sbi->s_group_desc[i]);
4557 	kvfree(sbi->s_group_desc);
4558 failed_mount:
4559 	if (sbi->s_chksum_driver)
4560 		crypto_free_shash(sbi->s_chksum_driver);
4561 #ifdef CONFIG_QUOTA
4562 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4563 		kfree(sbi->s_qf_names[i]);
4564 #endif
4565 	ext4_blkdev_remove(sbi);
4566 	brelse(bh);
4567 out_fail:
4568 	sb->s_fs_info = NULL;
4569 	kfree(sbi->s_blockgroup_lock);
4570 out_free_base:
4571 	kfree(sbi);
4572 	kfree(orig_data);
4573 	fs_put_dax(dax_dev);
4574 	return err ? err : ret;
4575 }
4576 
4577 /*
4578  * Setup any per-fs journal parameters now.  We'll do this both on
4579  * initial mount, once the journal has been initialised but before we've
4580  * done any recovery; and again on any subsequent remount.
4581  */
4582 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4583 {
4584 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4585 
4586 	journal->j_commit_interval = sbi->s_commit_interval;
4587 	journal->j_min_batch_time = sbi->s_min_batch_time;
4588 	journal->j_max_batch_time = sbi->s_max_batch_time;
4589 
4590 	write_lock(&journal->j_state_lock);
4591 	if (test_opt(sb, BARRIER))
4592 		journal->j_flags |= JBD2_BARRIER;
4593 	else
4594 		journal->j_flags &= ~JBD2_BARRIER;
4595 	if (test_opt(sb, DATA_ERR_ABORT))
4596 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4597 	else
4598 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4599 	write_unlock(&journal->j_state_lock);
4600 }
4601 
4602 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4603 					     unsigned int journal_inum)
4604 {
4605 	struct inode *journal_inode;
4606 
4607 	/*
4608 	 * Test for the existence of a valid inode on disk.  Bad things
4609 	 * happen if we iget() an unused inode, as the subsequent iput()
4610 	 * will try to delete it.
4611 	 */
4612 	journal_inode = ext4_iget(sb, journal_inum, EXT4_IGET_SPECIAL);
4613 	if (IS_ERR(journal_inode)) {
4614 		ext4_msg(sb, KERN_ERR, "no journal found");
4615 		return NULL;
4616 	}
4617 	if (!journal_inode->i_nlink) {
4618 		make_bad_inode(journal_inode);
4619 		iput(journal_inode);
4620 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4621 		return NULL;
4622 	}
4623 
4624 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4625 		  journal_inode, journal_inode->i_size);
4626 	if (!S_ISREG(journal_inode->i_mode)) {
4627 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4628 		iput(journal_inode);
4629 		return NULL;
4630 	}
4631 	return journal_inode;
4632 }
4633 
4634 static journal_t *ext4_get_journal(struct super_block *sb,
4635 				   unsigned int journal_inum)
4636 {
4637 	struct inode *journal_inode;
4638 	journal_t *journal;
4639 
4640 	BUG_ON(!ext4_has_feature_journal(sb));
4641 
4642 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4643 	if (!journal_inode)
4644 		return NULL;
4645 
4646 	journal = jbd2_journal_init_inode(journal_inode);
4647 	if (!journal) {
4648 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4649 		iput(journal_inode);
4650 		return NULL;
4651 	}
4652 	journal->j_private = sb;
4653 	ext4_init_journal_params(sb, journal);
4654 	return journal;
4655 }
4656 
4657 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4658 				       dev_t j_dev)
4659 {
4660 	struct buffer_head *bh;
4661 	journal_t *journal;
4662 	ext4_fsblk_t start;
4663 	ext4_fsblk_t len;
4664 	int hblock, blocksize;
4665 	ext4_fsblk_t sb_block;
4666 	unsigned long offset;
4667 	struct ext4_super_block *es;
4668 	struct block_device *bdev;
4669 
4670 	BUG_ON(!ext4_has_feature_journal(sb));
4671 
4672 	bdev = ext4_blkdev_get(j_dev, sb);
4673 	if (bdev == NULL)
4674 		return NULL;
4675 
4676 	blocksize = sb->s_blocksize;
4677 	hblock = bdev_logical_block_size(bdev);
4678 	if (blocksize < hblock) {
4679 		ext4_msg(sb, KERN_ERR,
4680 			"blocksize too small for journal device");
4681 		goto out_bdev;
4682 	}
4683 
4684 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4685 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4686 	set_blocksize(bdev, blocksize);
4687 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4688 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4689 		       "external journal");
4690 		goto out_bdev;
4691 	}
4692 
4693 	es = (struct ext4_super_block *) (bh->b_data + offset);
4694 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4695 	    !(le32_to_cpu(es->s_feature_incompat) &
4696 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4697 		ext4_msg(sb, KERN_ERR, "external journal has "
4698 					"bad superblock");
4699 		brelse(bh);
4700 		goto out_bdev;
4701 	}
4702 
4703 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4704 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4705 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4706 		ext4_msg(sb, KERN_ERR, "external journal has "
4707 				       "corrupt superblock");
4708 		brelse(bh);
4709 		goto out_bdev;
4710 	}
4711 
4712 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4713 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4714 		brelse(bh);
4715 		goto out_bdev;
4716 	}
4717 
4718 	len = ext4_blocks_count(es);
4719 	start = sb_block + 1;
4720 	brelse(bh);	/* we're done with the superblock */
4721 
4722 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4723 					start, len, blocksize);
4724 	if (!journal) {
4725 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4726 		goto out_bdev;
4727 	}
4728 	journal->j_private = sb;
4729 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4730 	wait_on_buffer(journal->j_sb_buffer);
4731 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4732 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4733 		goto out_journal;
4734 	}
4735 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4736 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4737 					"user (unsupported) - %d",
4738 			be32_to_cpu(journal->j_superblock->s_nr_users));
4739 		goto out_journal;
4740 	}
4741 	EXT4_SB(sb)->journal_bdev = bdev;
4742 	ext4_init_journal_params(sb, journal);
4743 	return journal;
4744 
4745 out_journal:
4746 	jbd2_journal_destroy(journal);
4747 out_bdev:
4748 	ext4_blkdev_put(bdev);
4749 	return NULL;
4750 }
4751 
4752 static int ext4_load_journal(struct super_block *sb,
4753 			     struct ext4_super_block *es,
4754 			     unsigned long journal_devnum)
4755 {
4756 	journal_t *journal;
4757 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4758 	dev_t journal_dev;
4759 	int err = 0;
4760 	int really_read_only;
4761 
4762 	BUG_ON(!ext4_has_feature_journal(sb));
4763 
4764 	if (journal_devnum &&
4765 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4766 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4767 			"numbers have changed");
4768 		journal_dev = new_decode_dev(journal_devnum);
4769 	} else
4770 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4771 
4772 	really_read_only = bdev_read_only(sb->s_bdev);
4773 
4774 	/*
4775 	 * Are we loading a blank journal or performing recovery after a
4776 	 * crash?  For recovery, we need to check in advance whether we
4777 	 * can get read-write access to the device.
4778 	 */
4779 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4780 		if (sb_rdonly(sb)) {
4781 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4782 					"required on readonly filesystem");
4783 			if (really_read_only) {
4784 				ext4_msg(sb, KERN_ERR, "write access "
4785 					"unavailable, cannot proceed "
4786 					"(try mounting with noload)");
4787 				return -EROFS;
4788 			}
4789 			ext4_msg(sb, KERN_INFO, "write access will "
4790 			       "be enabled during recovery");
4791 		}
4792 	}
4793 
4794 	if (journal_inum && journal_dev) {
4795 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4796 		       "and inode journals!");
4797 		return -EINVAL;
4798 	}
4799 
4800 	if (journal_inum) {
4801 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4802 			return -EINVAL;
4803 	} else {
4804 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4805 			return -EINVAL;
4806 	}
4807 
4808 	if (!(journal->j_flags & JBD2_BARRIER))
4809 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4810 
4811 	if (!ext4_has_feature_journal_needs_recovery(sb))
4812 		err = jbd2_journal_wipe(journal, !really_read_only);
4813 	if (!err) {
4814 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4815 		if (save)
4816 			memcpy(save, ((char *) es) +
4817 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4818 		err = jbd2_journal_load(journal);
4819 		if (save)
4820 			memcpy(((char *) es) + EXT4_S_ERR_START,
4821 			       save, EXT4_S_ERR_LEN);
4822 		kfree(save);
4823 	}
4824 
4825 	if (err) {
4826 		ext4_msg(sb, KERN_ERR, "error loading journal");
4827 		jbd2_journal_destroy(journal);
4828 		return err;
4829 	}
4830 
4831 	EXT4_SB(sb)->s_journal = journal;
4832 	ext4_clear_journal_err(sb, es);
4833 
4834 	if (!really_read_only && journal_devnum &&
4835 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4836 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4837 
4838 		/* Make sure we flush the recovery flag to disk. */
4839 		ext4_commit_super(sb, 1);
4840 	}
4841 
4842 	return 0;
4843 }
4844 
4845 static int ext4_commit_super(struct super_block *sb, int sync)
4846 {
4847 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4848 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4849 	int error = 0;
4850 
4851 	if (!sbh || block_device_ejected(sb))
4852 		return error;
4853 
4854 	/*
4855 	 * The superblock bh should be mapped, but it might not be if the
4856 	 * device was hot-removed. Not much we can do but fail the I/O.
4857 	 */
4858 	if (!buffer_mapped(sbh))
4859 		return error;
4860 
4861 	/*
4862 	 * If the file system is mounted read-only, don't update the
4863 	 * superblock write time.  This avoids updating the superblock
4864 	 * write time when we are mounting the root file system
4865 	 * read/only but we need to replay the journal; at that point,
4866 	 * for people who are east of GMT and who make their clock
4867 	 * tick in localtime for Windows bug-for-bug compatibility,
4868 	 * the clock is set in the future, and this will cause e2fsck
4869 	 * to complain and force a full file system check.
4870 	 */
4871 	if (!(sb->s_flags & SB_RDONLY))
4872 		ext4_update_tstamp(es, s_wtime);
4873 	if (sb->s_bdev->bd_part)
4874 		es->s_kbytes_written =
4875 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4876 			    ((part_stat_read(sb->s_bdev->bd_part,
4877 					     sectors[STAT_WRITE]) -
4878 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4879 	else
4880 		es->s_kbytes_written =
4881 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4882 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4883 		ext4_free_blocks_count_set(es,
4884 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4885 				&EXT4_SB(sb)->s_freeclusters_counter)));
4886 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4887 		es->s_free_inodes_count =
4888 			cpu_to_le32(percpu_counter_sum_positive(
4889 				&EXT4_SB(sb)->s_freeinodes_counter));
4890 	BUFFER_TRACE(sbh, "marking dirty");
4891 	ext4_superblock_csum_set(sb);
4892 	if (sync)
4893 		lock_buffer(sbh);
4894 	if (buffer_write_io_error(sbh)) {
4895 		/*
4896 		 * Oh, dear.  A previous attempt to write the
4897 		 * superblock failed.  This could happen because the
4898 		 * USB device was yanked out.  Or it could happen to
4899 		 * be a transient write error and maybe the block will
4900 		 * be remapped.  Nothing we can do but to retry the
4901 		 * write and hope for the best.
4902 		 */
4903 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4904 		       "superblock detected");
4905 		clear_buffer_write_io_error(sbh);
4906 		set_buffer_uptodate(sbh);
4907 	}
4908 	mark_buffer_dirty(sbh);
4909 	if (sync) {
4910 		unlock_buffer(sbh);
4911 		error = __sync_dirty_buffer(sbh,
4912 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4913 		if (buffer_write_io_error(sbh)) {
4914 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4915 			       "superblock");
4916 			clear_buffer_write_io_error(sbh);
4917 			set_buffer_uptodate(sbh);
4918 		}
4919 	}
4920 	return error;
4921 }
4922 
4923 /*
4924  * Have we just finished recovery?  If so, and if we are mounting (or
4925  * remounting) the filesystem readonly, then we will end up with a
4926  * consistent fs on disk.  Record that fact.
4927  */
4928 static void ext4_mark_recovery_complete(struct super_block *sb,
4929 					struct ext4_super_block *es)
4930 {
4931 	journal_t *journal = EXT4_SB(sb)->s_journal;
4932 
4933 	if (!ext4_has_feature_journal(sb)) {
4934 		BUG_ON(journal != NULL);
4935 		return;
4936 	}
4937 	jbd2_journal_lock_updates(journal);
4938 	if (jbd2_journal_flush(journal) < 0)
4939 		goto out;
4940 
4941 	if (ext4_has_feature_journal_needs_recovery(sb) && sb_rdonly(sb)) {
4942 		ext4_clear_feature_journal_needs_recovery(sb);
4943 		ext4_commit_super(sb, 1);
4944 	}
4945 
4946 out:
4947 	jbd2_journal_unlock_updates(journal);
4948 }
4949 
4950 /*
4951  * If we are mounting (or read-write remounting) a filesystem whose journal
4952  * has recorded an error from a previous lifetime, move that error to the
4953  * main filesystem now.
4954  */
4955 static void ext4_clear_journal_err(struct super_block *sb,
4956 				   struct ext4_super_block *es)
4957 {
4958 	journal_t *journal;
4959 	int j_errno;
4960 	const char *errstr;
4961 
4962 	BUG_ON(!ext4_has_feature_journal(sb));
4963 
4964 	journal = EXT4_SB(sb)->s_journal;
4965 
4966 	/*
4967 	 * Now check for any error status which may have been recorded in the
4968 	 * journal by a prior ext4_error() or ext4_abort()
4969 	 */
4970 
4971 	j_errno = jbd2_journal_errno(journal);
4972 	if (j_errno) {
4973 		char nbuf[16];
4974 
4975 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4976 		ext4_warning(sb, "Filesystem error recorded "
4977 			     "from previous mount: %s", errstr);
4978 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4979 
4980 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4981 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4982 		ext4_commit_super(sb, 1);
4983 
4984 		jbd2_journal_clear_err(journal);
4985 		jbd2_journal_update_sb_errno(journal);
4986 	}
4987 }
4988 
4989 /*
4990  * Force the running and committing transactions to commit,
4991  * and wait on the commit.
4992  */
4993 int ext4_force_commit(struct super_block *sb)
4994 {
4995 	journal_t *journal;
4996 
4997 	if (sb_rdonly(sb))
4998 		return 0;
4999 
5000 	journal = EXT4_SB(sb)->s_journal;
5001 	return ext4_journal_force_commit(journal);
5002 }
5003 
5004 static int ext4_sync_fs(struct super_block *sb, int wait)
5005 {
5006 	int ret = 0;
5007 	tid_t target;
5008 	bool needs_barrier = false;
5009 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5010 
5011 	if (unlikely(ext4_forced_shutdown(sbi)))
5012 		return 0;
5013 
5014 	trace_ext4_sync_fs(sb, wait);
5015 	flush_workqueue(sbi->rsv_conversion_wq);
5016 	/*
5017 	 * Writeback quota in non-journalled quota case - journalled quota has
5018 	 * no dirty dquots
5019 	 */
5020 	dquot_writeback_dquots(sb, -1);
5021 	/*
5022 	 * Data writeback is possible w/o journal transaction, so barrier must
5023 	 * being sent at the end of the function. But we can skip it if
5024 	 * transaction_commit will do it for us.
5025 	 */
5026 	if (sbi->s_journal) {
5027 		target = jbd2_get_latest_transaction(sbi->s_journal);
5028 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
5029 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
5030 			needs_barrier = true;
5031 
5032 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
5033 			if (wait)
5034 				ret = jbd2_log_wait_commit(sbi->s_journal,
5035 							   target);
5036 		}
5037 	} else if (wait && test_opt(sb, BARRIER))
5038 		needs_barrier = true;
5039 	if (needs_barrier) {
5040 		int err;
5041 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
5042 		if (!ret)
5043 			ret = err;
5044 	}
5045 
5046 	return ret;
5047 }
5048 
5049 /*
5050  * LVM calls this function before a (read-only) snapshot is created.  This
5051  * gives us a chance to flush the journal completely and mark the fs clean.
5052  *
5053  * Note that only this function cannot bring a filesystem to be in a clean
5054  * state independently. It relies on upper layer to stop all data & metadata
5055  * modifications.
5056  */
5057 static int ext4_freeze(struct super_block *sb)
5058 {
5059 	int error = 0;
5060 	journal_t *journal;
5061 
5062 	if (sb_rdonly(sb))
5063 		return 0;
5064 
5065 	journal = EXT4_SB(sb)->s_journal;
5066 
5067 	if (journal) {
5068 		/* Now we set up the journal barrier. */
5069 		jbd2_journal_lock_updates(journal);
5070 
5071 		/*
5072 		 * Don't clear the needs_recovery flag if we failed to
5073 		 * flush the journal.
5074 		 */
5075 		error = jbd2_journal_flush(journal);
5076 		if (error < 0)
5077 			goto out;
5078 
5079 		/* Journal blocked and flushed, clear needs_recovery flag. */
5080 		ext4_clear_feature_journal_needs_recovery(sb);
5081 	}
5082 
5083 	error = ext4_commit_super(sb, 1);
5084 out:
5085 	if (journal)
5086 		/* we rely on upper layer to stop further updates */
5087 		jbd2_journal_unlock_updates(journal);
5088 	return error;
5089 }
5090 
5091 /*
5092  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
5093  * flag here, even though the filesystem is not technically dirty yet.
5094  */
5095 static int ext4_unfreeze(struct super_block *sb)
5096 {
5097 	if (sb_rdonly(sb) || ext4_forced_shutdown(EXT4_SB(sb)))
5098 		return 0;
5099 
5100 	if (EXT4_SB(sb)->s_journal) {
5101 		/* Reset the needs_recovery flag before the fs is unlocked. */
5102 		ext4_set_feature_journal_needs_recovery(sb);
5103 	}
5104 
5105 	ext4_commit_super(sb, 1);
5106 	return 0;
5107 }
5108 
5109 /*
5110  * Structure to save mount options for ext4_remount's benefit
5111  */
5112 struct ext4_mount_options {
5113 	unsigned long s_mount_opt;
5114 	unsigned long s_mount_opt2;
5115 	kuid_t s_resuid;
5116 	kgid_t s_resgid;
5117 	unsigned long s_commit_interval;
5118 	u32 s_min_batch_time, s_max_batch_time;
5119 #ifdef CONFIG_QUOTA
5120 	int s_jquota_fmt;
5121 	char *s_qf_names[EXT4_MAXQUOTAS];
5122 #endif
5123 };
5124 
5125 static int ext4_remount(struct super_block *sb, int *flags, char *data)
5126 {
5127 	struct ext4_super_block *es;
5128 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5129 	unsigned long old_sb_flags;
5130 	struct ext4_mount_options old_opts;
5131 	int enable_quota = 0;
5132 	ext4_group_t g;
5133 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
5134 	int err = 0;
5135 #ifdef CONFIG_QUOTA
5136 	int i, j;
5137 	char *to_free[EXT4_MAXQUOTAS];
5138 #endif
5139 	char *orig_data = kstrdup(data, GFP_KERNEL);
5140 
5141 	if (data && !orig_data)
5142 		return -ENOMEM;
5143 
5144 	/* Store the original options */
5145 	old_sb_flags = sb->s_flags;
5146 	old_opts.s_mount_opt = sbi->s_mount_opt;
5147 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
5148 	old_opts.s_resuid = sbi->s_resuid;
5149 	old_opts.s_resgid = sbi->s_resgid;
5150 	old_opts.s_commit_interval = sbi->s_commit_interval;
5151 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
5152 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
5153 #ifdef CONFIG_QUOTA
5154 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
5155 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5156 		if (sbi->s_qf_names[i]) {
5157 			char *qf_name = get_qf_name(sb, sbi, i);
5158 
5159 			old_opts.s_qf_names[i] = kstrdup(qf_name, GFP_KERNEL);
5160 			if (!old_opts.s_qf_names[i]) {
5161 				for (j = 0; j < i; j++)
5162 					kfree(old_opts.s_qf_names[j]);
5163 				kfree(orig_data);
5164 				return -ENOMEM;
5165 			}
5166 		} else
5167 			old_opts.s_qf_names[i] = NULL;
5168 #endif
5169 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
5170 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
5171 
5172 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
5173 		err = -EINVAL;
5174 		goto restore_opts;
5175 	}
5176 
5177 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
5178 	    test_opt(sb, JOURNAL_CHECKSUM)) {
5179 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
5180 			 "during remount not supported; ignoring");
5181 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5182 	}
5183 
5184 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5185 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5186 			ext4_msg(sb, KERN_ERR, "can't mount with "
5187 				 "both data=journal and delalloc");
5188 			err = -EINVAL;
5189 			goto restore_opts;
5190 		}
5191 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5192 			ext4_msg(sb, KERN_ERR, "can't mount with "
5193 				 "both data=journal and dioread_nolock");
5194 			err = -EINVAL;
5195 			goto restore_opts;
5196 		}
5197 		if (test_opt(sb, DAX)) {
5198 			ext4_msg(sb, KERN_ERR, "can't mount with "
5199 				 "both data=journal and dax");
5200 			err = -EINVAL;
5201 			goto restore_opts;
5202 		}
5203 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5204 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5205 			ext4_msg(sb, KERN_ERR, "can't mount with "
5206 				"journal_async_commit in data=ordered mode");
5207 			err = -EINVAL;
5208 			goto restore_opts;
5209 		}
5210 	}
5211 
5212 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5213 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5214 		err = -EINVAL;
5215 		goto restore_opts;
5216 	}
5217 
5218 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5219 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5220 			"dax flag with busy inodes while remounting");
5221 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5222 	}
5223 
5224 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5225 		ext4_abort(sb, "Abort forced by user");
5226 
5227 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
5228 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);
5229 
5230 	es = sbi->s_es;
5231 
5232 	if (sbi->s_journal) {
5233 		ext4_init_journal_params(sb, sbi->s_journal);
5234 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5235 	}
5236 
5237 	if (*flags & SB_LAZYTIME)
5238 		sb->s_flags |= SB_LAZYTIME;
5239 
5240 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
5241 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5242 			err = -EROFS;
5243 			goto restore_opts;
5244 		}
5245 
5246 		if (*flags & SB_RDONLY) {
5247 			err = sync_filesystem(sb);
5248 			if (err < 0)
5249 				goto restore_opts;
5250 			err = dquot_suspend(sb, -1);
5251 			if (err < 0)
5252 				goto restore_opts;
5253 
5254 			/*
5255 			 * First of all, the unconditional stuff we have to do
5256 			 * to disable replay of the journal when we next remount
5257 			 */
5258 			sb->s_flags |= SB_RDONLY;
5259 
5260 			/*
5261 			 * OK, test if we are remounting a valid rw partition
5262 			 * readonly, and if so set the rdonly flag and then
5263 			 * mark the partition as valid again.
5264 			 */
5265 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5266 			    (sbi->s_mount_state & EXT4_VALID_FS))
5267 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5268 
5269 			if (sbi->s_journal)
5270 				ext4_mark_recovery_complete(sb, es);
5271 			if (sbi->s_mmp_tsk)
5272 				kthread_stop(sbi->s_mmp_tsk);
5273 		} else {
5274 			/* Make sure we can mount this feature set readwrite */
5275 			if (ext4_has_feature_readonly(sb) ||
5276 			    !ext4_feature_set_ok(sb, 0)) {
5277 				err = -EROFS;
5278 				goto restore_opts;
5279 			}
5280 			/*
5281 			 * Make sure the group descriptor checksums
5282 			 * are sane.  If they aren't, refuse to remount r/w.
5283 			 */
5284 			for (g = 0; g < sbi->s_groups_count; g++) {
5285 				struct ext4_group_desc *gdp =
5286 					ext4_get_group_desc(sb, g, NULL);
5287 
5288 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5289 					ext4_msg(sb, KERN_ERR,
5290 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5291 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5292 					       le16_to_cpu(gdp->bg_checksum));
5293 					err = -EFSBADCRC;
5294 					goto restore_opts;
5295 				}
5296 			}
5297 
5298 			/*
5299 			 * If we have an unprocessed orphan list hanging
5300 			 * around from a previously readonly bdev mount,
5301 			 * require a full umount/remount for now.
5302 			 */
5303 			if (es->s_last_orphan) {
5304 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5305 				       "remount RDWR because of unprocessed "
5306 				       "orphan inode list.  Please "
5307 				       "umount/remount instead");
5308 				err = -EINVAL;
5309 				goto restore_opts;
5310 			}
5311 
5312 			/*
5313 			 * Mounting a RDONLY partition read-write, so reread
5314 			 * and store the current valid flag.  (It may have
5315 			 * been changed by e2fsck since we originally mounted
5316 			 * the partition.)
5317 			 */
5318 			if (sbi->s_journal)
5319 				ext4_clear_journal_err(sb, es);
5320 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5321 
5322 			err = ext4_setup_super(sb, es, 0);
5323 			if (err)
5324 				goto restore_opts;
5325 
5326 			sb->s_flags &= ~SB_RDONLY;
5327 			if (ext4_has_feature_mmp(sb))
5328 				if (ext4_multi_mount_protect(sb,
5329 						le64_to_cpu(es->s_mmp_block))) {
5330 					err = -EROFS;
5331 					goto restore_opts;
5332 				}
5333 			enable_quota = 1;
5334 		}
5335 	}
5336 
5337 	/*
5338 	 * Reinitialize lazy itable initialization thread based on
5339 	 * current settings
5340 	 */
5341 	if (sb_rdonly(sb) || !test_opt(sb, INIT_INODE_TABLE))
5342 		ext4_unregister_li_request(sb);
5343 	else {
5344 		ext4_group_t first_not_zeroed;
5345 		first_not_zeroed = ext4_has_uninit_itable(sb);
5346 		ext4_register_li_request(sb, first_not_zeroed);
5347 	}
5348 
5349 	ext4_setup_system_zone(sb);
5350 	if (sbi->s_journal == NULL && !(old_sb_flags & SB_RDONLY)) {
5351 		err = ext4_commit_super(sb, 1);
5352 		if (err)
5353 			goto restore_opts;
5354 	}
5355 
5356 #ifdef CONFIG_QUOTA
5357 	/* Release old quota file names */
5358 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5359 		kfree(old_opts.s_qf_names[i]);
5360 	if (enable_quota) {
5361 		if (sb_any_quota_suspended(sb))
5362 			dquot_resume(sb, -1);
5363 		else if (ext4_has_feature_quota(sb)) {
5364 			err = ext4_enable_quotas(sb);
5365 			if (err)
5366 				goto restore_opts;
5367 		}
5368 	}
5369 #endif
5370 
5371 	*flags = (*flags & ~SB_LAZYTIME) | (sb->s_flags & SB_LAZYTIME);
5372 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5373 	kfree(orig_data);
5374 	return 0;
5375 
5376 restore_opts:
5377 	sb->s_flags = old_sb_flags;
5378 	sbi->s_mount_opt = old_opts.s_mount_opt;
5379 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5380 	sbi->s_resuid = old_opts.s_resuid;
5381 	sbi->s_resgid = old_opts.s_resgid;
5382 	sbi->s_commit_interval = old_opts.s_commit_interval;
5383 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5384 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5385 #ifdef CONFIG_QUOTA
5386 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5387 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5388 		to_free[i] = get_qf_name(sb, sbi, i);
5389 		rcu_assign_pointer(sbi->s_qf_names[i], old_opts.s_qf_names[i]);
5390 	}
5391 	synchronize_rcu();
5392 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5393 		kfree(to_free[i]);
5394 #endif
5395 	kfree(orig_data);
5396 	return err;
5397 }
5398 
5399 #ifdef CONFIG_QUOTA
5400 static int ext4_statfs_project(struct super_block *sb,
5401 			       kprojid_t projid, struct kstatfs *buf)
5402 {
5403 	struct kqid qid;
5404 	struct dquot *dquot;
5405 	u64 limit;
5406 	u64 curblock;
5407 
5408 	qid = make_kqid_projid(projid);
5409 	dquot = dqget(sb, qid);
5410 	if (IS_ERR(dquot))
5411 		return PTR_ERR(dquot);
5412 	spin_lock(&dquot->dq_dqb_lock);
5413 
5414 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5415 		 dquot->dq_dqb.dqb_bsoftlimit :
5416 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5417 	if (limit && buf->f_blocks > limit) {
5418 		curblock = (dquot->dq_dqb.dqb_curspace +
5419 			    dquot->dq_dqb.dqb_rsvspace) >> sb->s_blocksize_bits;
5420 		buf->f_blocks = limit;
5421 		buf->f_bfree = buf->f_bavail =
5422 			(buf->f_blocks > curblock) ?
5423 			 (buf->f_blocks - curblock) : 0;
5424 	}
5425 
5426 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5427 		dquot->dq_dqb.dqb_isoftlimit :
5428 		dquot->dq_dqb.dqb_ihardlimit;
5429 	if (limit && buf->f_files > limit) {
5430 		buf->f_files = limit;
5431 		buf->f_ffree =
5432 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5433 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5434 	}
5435 
5436 	spin_unlock(&dquot->dq_dqb_lock);
5437 	dqput(dquot);
5438 	return 0;
5439 }
5440 #endif
5441 
5442 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5443 {
5444 	struct super_block *sb = dentry->d_sb;
5445 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5446 	struct ext4_super_block *es = sbi->s_es;
5447 	ext4_fsblk_t overhead = 0, resv_blocks;
5448 	u64 fsid;
5449 	s64 bfree;
5450 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5451 
5452 	if (!test_opt(sb, MINIX_DF))
5453 		overhead = sbi->s_overhead;
5454 
5455 	buf->f_type = EXT4_SUPER_MAGIC;
5456 	buf->f_bsize = sb->s_blocksize;
5457 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5458 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5459 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5460 	/* prevent underflow in case that few free space is available */
5461 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5462 	buf->f_bavail = buf->f_bfree -
5463 			(ext4_r_blocks_count(es) + resv_blocks);
5464 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5465 		buf->f_bavail = 0;
5466 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5467 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5468 	buf->f_namelen = EXT4_NAME_LEN;
5469 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5470 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5471 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5472 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5473 
5474 #ifdef CONFIG_QUOTA
5475 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5476 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5477 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5478 #endif
5479 	return 0;
5480 }
5481 
5482 
5483 #ifdef CONFIG_QUOTA
5484 
5485 /*
5486  * Helper functions so that transaction is started before we acquire dqio_sem
5487  * to keep correct lock ordering of transaction > dqio_sem
5488  */
5489 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5490 {
5491 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5492 }
5493 
5494 static int ext4_write_dquot(struct dquot *dquot)
5495 {
5496 	int ret, err;
5497 	handle_t *handle;
5498 	struct inode *inode;
5499 
5500 	inode = dquot_to_inode(dquot);
5501 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5502 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5503 	if (IS_ERR(handle))
5504 		return PTR_ERR(handle);
5505 	ret = dquot_commit(dquot);
5506 	err = ext4_journal_stop(handle);
5507 	if (!ret)
5508 		ret = err;
5509 	return ret;
5510 }
5511 
5512 static int ext4_acquire_dquot(struct dquot *dquot)
5513 {
5514 	int ret, err;
5515 	handle_t *handle;
5516 
5517 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5518 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5519 	if (IS_ERR(handle))
5520 		return PTR_ERR(handle);
5521 	ret = dquot_acquire(dquot);
5522 	err = ext4_journal_stop(handle);
5523 	if (!ret)
5524 		ret = err;
5525 	return ret;
5526 }
5527 
5528 static int ext4_release_dquot(struct dquot *dquot)
5529 {
5530 	int ret, err;
5531 	handle_t *handle;
5532 
5533 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5534 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5535 	if (IS_ERR(handle)) {
5536 		/* Release dquot anyway to avoid endless cycle in dqput() */
5537 		dquot_release(dquot);
5538 		return PTR_ERR(handle);
5539 	}
5540 	ret = dquot_release(dquot);
5541 	err = ext4_journal_stop(handle);
5542 	if (!ret)
5543 		ret = err;
5544 	return ret;
5545 }
5546 
5547 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5548 {
5549 	struct super_block *sb = dquot->dq_sb;
5550 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5551 
5552 	/* Are we journaling quotas? */
5553 	if (ext4_has_feature_quota(sb) ||
5554 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5555 		dquot_mark_dquot_dirty(dquot);
5556 		return ext4_write_dquot(dquot);
5557 	} else {
5558 		return dquot_mark_dquot_dirty(dquot);
5559 	}
5560 }
5561 
5562 static int ext4_write_info(struct super_block *sb, int type)
5563 {
5564 	int ret, err;
5565 	handle_t *handle;
5566 
5567 	/* Data block + inode block */
5568 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5569 	if (IS_ERR(handle))
5570 		return PTR_ERR(handle);
5571 	ret = dquot_commit_info(sb, type);
5572 	err = ext4_journal_stop(handle);
5573 	if (!ret)
5574 		ret = err;
5575 	return ret;
5576 }
5577 
5578 /*
5579  * Turn on quotas during mount time - we need to find
5580  * the quota file and such...
5581  */
5582 static int ext4_quota_on_mount(struct super_block *sb, int type)
5583 {
5584 	return dquot_quota_on_mount(sb, get_qf_name(sb, EXT4_SB(sb), type),
5585 					EXT4_SB(sb)->s_jquota_fmt, type);
5586 }
5587 
5588 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5589 {
5590 	struct ext4_inode_info *ei = EXT4_I(inode);
5591 
5592 	/* The first argument of lockdep_set_subclass has to be
5593 	 * *exactly* the same as the argument to init_rwsem() --- in
5594 	 * this case, in init_once() --- or lockdep gets unhappy
5595 	 * because the name of the lock is set using the
5596 	 * stringification of the argument to init_rwsem().
5597 	 */
5598 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5599 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5600 }
5601 
5602 /*
5603  * Standard function to be called on quota_on
5604  */
5605 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5606 			 const struct path *path)
5607 {
5608 	int err;
5609 
5610 	if (!test_opt(sb, QUOTA))
5611 		return -EINVAL;
5612 
5613 	/* Quotafile not on the same filesystem? */
5614 	if (path->dentry->d_sb != sb)
5615 		return -EXDEV;
5616 	/* Journaling quota? */
5617 	if (EXT4_SB(sb)->s_qf_names[type]) {
5618 		/* Quotafile not in fs root? */
5619 		if (path->dentry->d_parent != sb->s_root)
5620 			ext4_msg(sb, KERN_WARNING,
5621 				"Quota file not on filesystem root. "
5622 				"Journaled quota will not work");
5623 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5624 	} else {
5625 		/*
5626 		 * Clear the flag just in case mount options changed since
5627 		 * last time.
5628 		 */
5629 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5630 	}
5631 
5632 	/*
5633 	 * When we journal data on quota file, we have to flush journal to see
5634 	 * all updates to the file when we bypass pagecache...
5635 	 */
5636 	if (EXT4_SB(sb)->s_journal &&
5637 	    ext4_should_journal_data(d_inode(path->dentry))) {
5638 		/*
5639 		 * We don't need to lock updates but journal_flush() could
5640 		 * otherwise be livelocked...
5641 		 */
5642 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5643 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5644 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5645 		if (err)
5646 			return err;
5647 	}
5648 
5649 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5650 	err = dquot_quota_on(sb, type, format_id, path);
5651 	if (err) {
5652 		lockdep_set_quota_inode(path->dentry->d_inode,
5653 					     I_DATA_SEM_NORMAL);
5654 	} else {
5655 		struct inode *inode = d_inode(path->dentry);
5656 		handle_t *handle;
5657 
5658 		/*
5659 		 * Set inode flags to prevent userspace from messing with quota
5660 		 * files. If this fails, we return success anyway since quotas
5661 		 * are already enabled and this is not a hard failure.
5662 		 */
5663 		inode_lock(inode);
5664 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5665 		if (IS_ERR(handle))
5666 			goto unlock_inode;
5667 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5668 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5669 				S_NOATIME | S_IMMUTABLE);
5670 		ext4_mark_inode_dirty(handle, inode);
5671 		ext4_journal_stop(handle);
5672 	unlock_inode:
5673 		inode_unlock(inode);
5674 	}
5675 	return err;
5676 }
5677 
5678 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5679 			     unsigned int flags)
5680 {
5681 	int err;
5682 	struct inode *qf_inode;
5683 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5684 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5685 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5686 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5687 	};
5688 
5689 	BUG_ON(!ext4_has_feature_quota(sb));
5690 
5691 	if (!qf_inums[type])
5692 		return -EPERM;
5693 
5694 	qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL);
5695 	if (IS_ERR(qf_inode)) {
5696 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5697 		return PTR_ERR(qf_inode);
5698 	}
5699 
5700 	/* Don't account quota for quota files to avoid recursion */
5701 	qf_inode->i_flags |= S_NOQUOTA;
5702 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5703 	err = dquot_enable(qf_inode, type, format_id, flags);
5704 	if (err)
5705 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5706 	iput(qf_inode);
5707 
5708 	return err;
5709 }
5710 
5711 /* Enable usage tracking for all quota types. */
5712 static int ext4_enable_quotas(struct super_block *sb)
5713 {
5714 	int type, err = 0;
5715 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5716 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5717 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5718 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5719 	};
5720 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5721 		test_opt(sb, USRQUOTA),
5722 		test_opt(sb, GRPQUOTA),
5723 		test_opt(sb, PRJQUOTA),
5724 	};
5725 
5726 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5727 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5728 		if (qf_inums[type]) {
5729 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5730 				DQUOT_USAGE_ENABLED |
5731 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5732 			if (err) {
5733 				ext4_warning(sb,
5734 					"Failed to enable quota tracking "
5735 					"(type=%d, err=%d). Please run "
5736 					"e2fsck to fix.", type, err);
5737 				for (type--; type >= 0; type--)
5738 					dquot_quota_off(sb, type);
5739 
5740 				return err;
5741 			}
5742 		}
5743 	}
5744 	return 0;
5745 }
5746 
5747 static int ext4_quota_off(struct super_block *sb, int type)
5748 {
5749 	struct inode *inode = sb_dqopt(sb)->files[type];
5750 	handle_t *handle;
5751 	int err;
5752 
5753 	/* Force all delayed allocation blocks to be allocated.
5754 	 * Caller already holds s_umount sem */
5755 	if (test_opt(sb, DELALLOC))
5756 		sync_filesystem(sb);
5757 
5758 	if (!inode || !igrab(inode))
5759 		goto out;
5760 
5761 	err = dquot_quota_off(sb, type);
5762 	if (err || ext4_has_feature_quota(sb))
5763 		goto out_put;
5764 
5765 	inode_lock(inode);
5766 	/*
5767 	 * Update modification times of quota files when userspace can
5768 	 * start looking at them. If we fail, we return success anyway since
5769 	 * this is not a hard failure and quotas are already disabled.
5770 	 */
5771 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5772 	if (IS_ERR(handle))
5773 		goto out_unlock;
5774 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5775 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5776 	inode->i_mtime = inode->i_ctime = current_time(inode);
5777 	ext4_mark_inode_dirty(handle, inode);
5778 	ext4_journal_stop(handle);
5779 out_unlock:
5780 	inode_unlock(inode);
5781 out_put:
5782 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5783 	iput(inode);
5784 	return err;
5785 out:
5786 	return dquot_quota_off(sb, type);
5787 }
5788 
5789 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5790  * acquiring the locks... As quota files are never truncated and quota code
5791  * itself serializes the operations (and no one else should touch the files)
5792  * we don't have to be afraid of races */
5793 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5794 			       size_t len, loff_t off)
5795 {
5796 	struct inode *inode = sb_dqopt(sb)->files[type];
5797 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5798 	int offset = off & (sb->s_blocksize - 1);
5799 	int tocopy;
5800 	size_t toread;
5801 	struct buffer_head *bh;
5802 	loff_t i_size = i_size_read(inode);
5803 
5804 	if (off > i_size)
5805 		return 0;
5806 	if (off+len > i_size)
5807 		len = i_size-off;
5808 	toread = len;
5809 	while (toread > 0) {
5810 		tocopy = sb->s_blocksize - offset < toread ?
5811 				sb->s_blocksize - offset : toread;
5812 		bh = ext4_bread(NULL, inode, blk, 0);
5813 		if (IS_ERR(bh))
5814 			return PTR_ERR(bh);
5815 		if (!bh)	/* A hole? */
5816 			memset(data, 0, tocopy);
5817 		else
5818 			memcpy(data, bh->b_data+offset, tocopy);
5819 		brelse(bh);
5820 		offset = 0;
5821 		toread -= tocopy;
5822 		data += tocopy;
5823 		blk++;
5824 	}
5825 	return len;
5826 }
5827 
5828 /* Write to quotafile (we know the transaction is already started and has
5829  * enough credits) */
5830 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5831 				const char *data, size_t len, loff_t off)
5832 {
5833 	struct inode *inode = sb_dqopt(sb)->files[type];
5834 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5835 	int err, offset = off & (sb->s_blocksize - 1);
5836 	int retries = 0;
5837 	struct buffer_head *bh;
5838 	handle_t *handle = journal_current_handle();
5839 
5840 	if (EXT4_SB(sb)->s_journal && !handle) {
5841 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5842 			" cancelled because transaction is not started",
5843 			(unsigned long long)off, (unsigned long long)len);
5844 		return -EIO;
5845 	}
5846 	/*
5847 	 * Since we account only one data block in transaction credits,
5848 	 * then it is impossible to cross a block boundary.
5849 	 */
5850 	if (sb->s_blocksize - offset < len) {
5851 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5852 			" cancelled because not block aligned",
5853 			(unsigned long long)off, (unsigned long long)len);
5854 		return -EIO;
5855 	}
5856 
5857 	do {
5858 		bh = ext4_bread(handle, inode, blk,
5859 				EXT4_GET_BLOCKS_CREATE |
5860 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5861 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5862 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5863 	if (IS_ERR(bh))
5864 		return PTR_ERR(bh);
5865 	if (!bh)
5866 		goto out;
5867 	BUFFER_TRACE(bh, "get write access");
5868 	err = ext4_journal_get_write_access(handle, bh);
5869 	if (err) {
5870 		brelse(bh);
5871 		return err;
5872 	}
5873 	lock_buffer(bh);
5874 	memcpy(bh->b_data+offset, data, len);
5875 	flush_dcache_page(bh->b_page);
5876 	unlock_buffer(bh);
5877 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5878 	brelse(bh);
5879 out:
5880 	if (inode->i_size < off + len) {
5881 		i_size_write(inode, off + len);
5882 		EXT4_I(inode)->i_disksize = inode->i_size;
5883 		ext4_mark_inode_dirty(handle, inode);
5884 	}
5885 	return len;
5886 }
5887 
5888 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5889 {
5890 	const struct quota_format_ops	*ops;
5891 
5892 	if (!sb_has_quota_loaded(sb, qid->type))
5893 		return -ESRCH;
5894 	ops = sb_dqopt(sb)->ops[qid->type];
5895 	if (!ops || !ops->get_next_id)
5896 		return -ENOSYS;
5897 	return dquot_get_next_id(sb, qid);
5898 }
5899 #endif
5900 
5901 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5902 		       const char *dev_name, void *data)
5903 {
5904 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5905 }
5906 
5907 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5908 static inline void register_as_ext2(void)
5909 {
5910 	int err = register_filesystem(&ext2_fs_type);
5911 	if (err)
5912 		printk(KERN_WARNING
5913 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5914 }
5915 
5916 static inline void unregister_as_ext2(void)
5917 {
5918 	unregister_filesystem(&ext2_fs_type);
5919 }
5920 
5921 static inline int ext2_feature_set_ok(struct super_block *sb)
5922 {
5923 	if (ext4_has_unknown_ext2_incompat_features(sb))
5924 		return 0;
5925 	if (sb_rdonly(sb))
5926 		return 1;
5927 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5928 		return 0;
5929 	return 1;
5930 }
5931 #else
5932 static inline void register_as_ext2(void) { }
5933 static inline void unregister_as_ext2(void) { }
5934 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5935 #endif
5936 
5937 static inline void register_as_ext3(void)
5938 {
5939 	int err = register_filesystem(&ext3_fs_type);
5940 	if (err)
5941 		printk(KERN_WARNING
5942 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5943 }
5944 
5945 static inline void unregister_as_ext3(void)
5946 {
5947 	unregister_filesystem(&ext3_fs_type);
5948 }
5949 
5950 static inline int ext3_feature_set_ok(struct super_block *sb)
5951 {
5952 	if (ext4_has_unknown_ext3_incompat_features(sb))
5953 		return 0;
5954 	if (!ext4_has_feature_journal(sb))
5955 		return 0;
5956 	if (sb_rdonly(sb))
5957 		return 1;
5958 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5959 		return 0;
5960 	return 1;
5961 }
5962 
5963 static struct file_system_type ext4_fs_type = {
5964 	.owner		= THIS_MODULE,
5965 	.name		= "ext4",
5966 	.mount		= ext4_mount,
5967 	.kill_sb	= kill_block_super,
5968 	.fs_flags	= FS_REQUIRES_DEV,
5969 };
5970 MODULE_ALIAS_FS("ext4");
5971 
5972 /* Shared across all ext4 file systems */
5973 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5974 
5975 static int __init ext4_init_fs(void)
5976 {
5977 	int i, err;
5978 
5979 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5980 	ext4_li_info = NULL;
5981 	mutex_init(&ext4_li_mtx);
5982 
5983 	/* Build-time check for flags consistency */
5984 	ext4_check_flag_values();
5985 
5986 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5987 		init_waitqueue_head(&ext4__ioend_wq[i]);
5988 
5989 	err = ext4_init_es();
5990 	if (err)
5991 		return err;
5992 
5993 	err = ext4_init_pending();
5994 	if (err)
5995 		goto out6;
5996 
5997 	err = ext4_init_pageio();
5998 	if (err)
5999 		goto out5;
6000 
6001 	err = ext4_init_system_zone();
6002 	if (err)
6003 		goto out4;
6004 
6005 	err = ext4_init_sysfs();
6006 	if (err)
6007 		goto out3;
6008 
6009 	err = ext4_init_mballoc();
6010 	if (err)
6011 		goto out2;
6012 	err = init_inodecache();
6013 	if (err)
6014 		goto out1;
6015 	register_as_ext3();
6016 	register_as_ext2();
6017 	err = register_filesystem(&ext4_fs_type);
6018 	if (err)
6019 		goto out;
6020 
6021 	return 0;
6022 out:
6023 	unregister_as_ext2();
6024 	unregister_as_ext3();
6025 	destroy_inodecache();
6026 out1:
6027 	ext4_exit_mballoc();
6028 out2:
6029 	ext4_exit_sysfs();
6030 out3:
6031 	ext4_exit_system_zone();
6032 out4:
6033 	ext4_exit_pageio();
6034 out5:
6035 	ext4_exit_pending();
6036 out6:
6037 	ext4_exit_es();
6038 
6039 	return err;
6040 }
6041 
6042 static void __exit ext4_exit_fs(void)
6043 {
6044 	ext4_destroy_lazyinit_thread();
6045 	unregister_as_ext2();
6046 	unregister_as_ext3();
6047 	unregister_filesystem(&ext4_fs_type);
6048 	destroy_inodecache();
6049 	ext4_exit_mballoc();
6050 	ext4_exit_sysfs();
6051 	ext4_exit_system_zone();
6052 	ext4_exit_pageio();
6053 	ext4_exit_es();
6054 	ext4_exit_pending();
6055 }
6056 
6057 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
6058 MODULE_DESCRIPTION("Fourth Extended Filesystem");
6059 MODULE_LICENSE("GPL");
6060 MODULE_SOFTDEP("pre: crc32c");
6061 module_init(ext4_init_fs)
6062 module_exit(ext4_exit_fs)
6063