xref: /linux/fs/ext4/super.c (revision a89988a6e00c5a099ee23619cd91dc8dc7ec9328)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/slab.h>
25 #include <linux/init.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/ctype.h>
38 #include <linux/log2.h>
39 #include <linux/crc16.h>
40 #include <linux/cleancache.h>
41 #include <linux/uaccess.h>
42 
43 #include <linux/kthread.h>
44 #include <linux/freezer.h>
45 
46 #include "ext4.h"
47 #include "ext4_extents.h"	/* Needed for trace points definition */
48 #include "ext4_jbd2.h"
49 #include "xattr.h"
50 #include "acl.h"
51 #include "mballoc.h"
52 
53 #define CREATE_TRACE_POINTS
54 #include <trace/events/ext4.h>
55 
56 static struct ext4_lazy_init *ext4_li_info;
57 static struct mutex ext4_li_mtx;
58 static struct ratelimit_state ext4_mount_msg_ratelimit;
59 
60 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
61 			     unsigned long journal_devnum);
62 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
63 static int ext4_commit_super(struct super_block *sb, int sync);
64 static void ext4_mark_recovery_complete(struct super_block *sb,
65 					struct ext4_super_block *es);
66 static void ext4_clear_journal_err(struct super_block *sb,
67 				   struct ext4_super_block *es);
68 static int ext4_sync_fs(struct super_block *sb, int wait);
69 static int ext4_remount(struct super_block *sb, int *flags, char *data);
70 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
71 static int ext4_unfreeze(struct super_block *sb);
72 static int ext4_freeze(struct super_block *sb);
73 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
74 		       const char *dev_name, void *data);
75 static inline int ext2_feature_set_ok(struct super_block *sb);
76 static inline int ext3_feature_set_ok(struct super_block *sb);
77 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
78 static void ext4_destroy_lazyinit_thread(void);
79 static void ext4_unregister_li_request(struct super_block *sb);
80 static void ext4_clear_request_list(void);
81 static struct inode *ext4_get_journal_inode(struct super_block *sb,
82 					    unsigned int journal_inum);
83 
84 /*
85  * Lock ordering
86  *
87  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
88  * i_mmap_rwsem (inode->i_mmap_rwsem)!
89  *
90  * page fault path:
91  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
92  *   page lock -> i_data_sem (rw)
93  *
94  * buffered write path:
95  * sb_start_write -> i_mutex -> mmap_sem
96  * sb_start_write -> i_mutex -> transaction start -> page lock ->
97  *   i_data_sem (rw)
98  *
99  * truncate:
100  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
101  *   i_mmap_rwsem (w) -> page lock
102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
103  *   transaction start -> i_data_sem (rw)
104  *
105  * direct IO:
106  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
107  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
108  *   transaction start -> i_data_sem (rw)
109  *
110  * writepages:
111  * transaction start -> page lock(s) -> i_data_sem (rw)
112  */
113 
114 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
115 static struct file_system_type ext2_fs_type = {
116 	.owner		= THIS_MODULE,
117 	.name		= "ext2",
118 	.mount		= ext4_mount,
119 	.kill_sb	= kill_block_super,
120 	.fs_flags	= FS_REQUIRES_DEV,
121 };
122 MODULE_ALIAS_FS("ext2");
123 MODULE_ALIAS("ext2");
124 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
125 #else
126 #define IS_EXT2_SB(sb) (0)
127 #endif
128 
129 
130 static struct file_system_type ext3_fs_type = {
131 	.owner		= THIS_MODULE,
132 	.name		= "ext3",
133 	.mount		= ext4_mount,
134 	.kill_sb	= kill_block_super,
135 	.fs_flags	= FS_REQUIRES_DEV,
136 };
137 MODULE_ALIAS_FS("ext3");
138 MODULE_ALIAS("ext3");
139 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
140 
141 static int ext4_verify_csum_type(struct super_block *sb,
142 				 struct ext4_super_block *es)
143 {
144 	if (!ext4_has_feature_metadata_csum(sb))
145 		return 1;
146 
147 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
148 }
149 
150 static __le32 ext4_superblock_csum(struct super_block *sb,
151 				   struct ext4_super_block *es)
152 {
153 	struct ext4_sb_info *sbi = EXT4_SB(sb);
154 	int offset = offsetof(struct ext4_super_block, s_checksum);
155 	__u32 csum;
156 
157 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
158 
159 	return cpu_to_le32(csum);
160 }
161 
162 static int ext4_superblock_csum_verify(struct super_block *sb,
163 				       struct ext4_super_block *es)
164 {
165 	if (!ext4_has_metadata_csum(sb))
166 		return 1;
167 
168 	return es->s_checksum == ext4_superblock_csum(sb, es);
169 }
170 
171 void ext4_superblock_csum_set(struct super_block *sb)
172 {
173 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
174 
175 	if (!ext4_has_metadata_csum(sb))
176 		return;
177 
178 	es->s_checksum = ext4_superblock_csum(sb, es);
179 }
180 
181 void *ext4_kvmalloc(size_t size, gfp_t flags)
182 {
183 	void *ret;
184 
185 	ret = kmalloc(size, flags | __GFP_NOWARN);
186 	if (!ret)
187 		ret = __vmalloc(size, flags, PAGE_KERNEL);
188 	return ret;
189 }
190 
191 void *ext4_kvzalloc(size_t size, gfp_t flags)
192 {
193 	void *ret;
194 
195 	ret = kzalloc(size, flags | __GFP_NOWARN);
196 	if (!ret)
197 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
198 	return ret;
199 }
200 
201 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
202 			       struct ext4_group_desc *bg)
203 {
204 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
205 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
206 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
207 }
208 
209 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
210 			       struct ext4_group_desc *bg)
211 {
212 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
213 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
214 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
215 }
216 
217 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
218 			      struct ext4_group_desc *bg)
219 {
220 	return le32_to_cpu(bg->bg_inode_table_lo) |
221 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
222 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
223 }
224 
225 __u32 ext4_free_group_clusters(struct super_block *sb,
226 			       struct ext4_group_desc *bg)
227 {
228 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
229 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
230 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
231 }
232 
233 __u32 ext4_free_inodes_count(struct super_block *sb,
234 			      struct ext4_group_desc *bg)
235 {
236 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
237 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
238 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
239 }
240 
241 __u32 ext4_used_dirs_count(struct super_block *sb,
242 			      struct ext4_group_desc *bg)
243 {
244 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
245 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
246 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
247 }
248 
249 __u32 ext4_itable_unused_count(struct super_block *sb,
250 			      struct ext4_group_desc *bg)
251 {
252 	return le16_to_cpu(bg->bg_itable_unused_lo) |
253 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
254 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
255 }
256 
257 void ext4_block_bitmap_set(struct super_block *sb,
258 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
259 {
260 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
261 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
262 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
263 }
264 
265 void ext4_inode_bitmap_set(struct super_block *sb,
266 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
267 {
268 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
269 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
270 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
271 }
272 
273 void ext4_inode_table_set(struct super_block *sb,
274 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
275 {
276 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
277 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
278 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
279 }
280 
281 void ext4_free_group_clusters_set(struct super_block *sb,
282 				  struct ext4_group_desc *bg, __u32 count)
283 {
284 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
285 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
286 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
287 }
288 
289 void ext4_free_inodes_set(struct super_block *sb,
290 			  struct ext4_group_desc *bg, __u32 count)
291 {
292 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
293 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
294 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
295 }
296 
297 void ext4_used_dirs_set(struct super_block *sb,
298 			  struct ext4_group_desc *bg, __u32 count)
299 {
300 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
301 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
302 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
303 }
304 
305 void ext4_itable_unused_set(struct super_block *sb,
306 			  struct ext4_group_desc *bg, __u32 count)
307 {
308 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
309 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
310 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
311 }
312 
313 
314 static void __save_error_info(struct super_block *sb, const char *func,
315 			    unsigned int line)
316 {
317 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
318 
319 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
320 	if (bdev_read_only(sb->s_bdev))
321 		return;
322 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
323 	es->s_last_error_time = cpu_to_le32(get_seconds());
324 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
325 	es->s_last_error_line = cpu_to_le32(line);
326 	if (!es->s_first_error_time) {
327 		es->s_first_error_time = es->s_last_error_time;
328 		strncpy(es->s_first_error_func, func,
329 			sizeof(es->s_first_error_func));
330 		es->s_first_error_line = cpu_to_le32(line);
331 		es->s_first_error_ino = es->s_last_error_ino;
332 		es->s_first_error_block = es->s_last_error_block;
333 	}
334 	/*
335 	 * Start the daily error reporting function if it hasn't been
336 	 * started already
337 	 */
338 	if (!es->s_error_count)
339 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
340 	le32_add_cpu(&es->s_error_count, 1);
341 }
342 
343 static void save_error_info(struct super_block *sb, const char *func,
344 			    unsigned int line)
345 {
346 	__save_error_info(sb, func, line);
347 	ext4_commit_super(sb, 1);
348 }
349 
350 /*
351  * The del_gendisk() function uninitializes the disk-specific data
352  * structures, including the bdi structure, without telling anyone
353  * else.  Once this happens, any attempt to call mark_buffer_dirty()
354  * (for example, by ext4_commit_super), will cause a kernel OOPS.
355  * This is a kludge to prevent these oops until we can put in a proper
356  * hook in del_gendisk() to inform the VFS and file system layers.
357  */
358 static int block_device_ejected(struct super_block *sb)
359 {
360 	struct inode *bd_inode = sb->s_bdev->bd_inode;
361 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
362 
363 	return bdi->dev == NULL;
364 }
365 
366 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
367 {
368 	struct super_block		*sb = journal->j_private;
369 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
370 	int				error = is_journal_aborted(journal);
371 	struct ext4_journal_cb_entry	*jce;
372 
373 	BUG_ON(txn->t_state == T_FINISHED);
374 	spin_lock(&sbi->s_md_lock);
375 	while (!list_empty(&txn->t_private_list)) {
376 		jce = list_entry(txn->t_private_list.next,
377 				 struct ext4_journal_cb_entry, jce_list);
378 		list_del_init(&jce->jce_list);
379 		spin_unlock(&sbi->s_md_lock);
380 		jce->jce_func(sb, jce, error);
381 		spin_lock(&sbi->s_md_lock);
382 	}
383 	spin_unlock(&sbi->s_md_lock);
384 }
385 
386 /* Deal with the reporting of failure conditions on a filesystem such as
387  * inconsistencies detected or read IO failures.
388  *
389  * On ext2, we can store the error state of the filesystem in the
390  * superblock.  That is not possible on ext4, because we may have other
391  * write ordering constraints on the superblock which prevent us from
392  * writing it out straight away; and given that the journal is about to
393  * be aborted, we can't rely on the current, or future, transactions to
394  * write out the superblock safely.
395  *
396  * We'll just use the jbd2_journal_abort() error code to record an error in
397  * the journal instead.  On recovery, the journal will complain about
398  * that error until we've noted it down and cleared it.
399  */
400 
401 static void ext4_handle_error(struct super_block *sb)
402 {
403 	if (sb->s_flags & MS_RDONLY)
404 		return;
405 
406 	if (!test_opt(sb, ERRORS_CONT)) {
407 		journal_t *journal = EXT4_SB(sb)->s_journal;
408 
409 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
410 		if (journal)
411 			jbd2_journal_abort(journal, -EIO);
412 	}
413 	if (test_opt(sb, ERRORS_RO)) {
414 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
415 		/*
416 		 * Make sure updated value of ->s_mount_flags will be visible
417 		 * before ->s_flags update
418 		 */
419 		smp_wmb();
420 		sb->s_flags |= MS_RDONLY;
421 	}
422 	if (test_opt(sb, ERRORS_PANIC)) {
423 		if (EXT4_SB(sb)->s_journal &&
424 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
425 			return;
426 		panic("EXT4-fs (device %s): panic forced after error\n",
427 			sb->s_id);
428 	}
429 }
430 
431 #define ext4_error_ratelimit(sb)					\
432 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
433 			     "EXT4-fs error")
434 
435 void __ext4_error(struct super_block *sb, const char *function,
436 		  unsigned int line, const char *fmt, ...)
437 {
438 	struct va_format vaf;
439 	va_list args;
440 
441 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
442 		return;
443 
444 	if (ext4_error_ratelimit(sb)) {
445 		va_start(args, fmt);
446 		vaf.fmt = fmt;
447 		vaf.va = &args;
448 		printk(KERN_CRIT
449 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
450 		       sb->s_id, function, line, current->comm, &vaf);
451 		va_end(args);
452 	}
453 	save_error_info(sb, function, line);
454 	ext4_handle_error(sb);
455 }
456 
457 void __ext4_error_inode(struct inode *inode, const char *function,
458 			unsigned int line, ext4_fsblk_t block,
459 			const char *fmt, ...)
460 {
461 	va_list args;
462 	struct va_format vaf;
463 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
464 
465 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
466 		return;
467 
468 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
469 	es->s_last_error_block = cpu_to_le64(block);
470 	if (ext4_error_ratelimit(inode->i_sb)) {
471 		va_start(args, fmt);
472 		vaf.fmt = fmt;
473 		vaf.va = &args;
474 		if (block)
475 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
476 			       "inode #%lu: block %llu: comm %s: %pV\n",
477 			       inode->i_sb->s_id, function, line, inode->i_ino,
478 			       block, current->comm, &vaf);
479 		else
480 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
481 			       "inode #%lu: comm %s: %pV\n",
482 			       inode->i_sb->s_id, function, line, inode->i_ino,
483 			       current->comm, &vaf);
484 		va_end(args);
485 	}
486 	save_error_info(inode->i_sb, function, line);
487 	ext4_handle_error(inode->i_sb);
488 }
489 
490 void __ext4_error_file(struct file *file, const char *function,
491 		       unsigned int line, ext4_fsblk_t block,
492 		       const char *fmt, ...)
493 {
494 	va_list args;
495 	struct va_format vaf;
496 	struct ext4_super_block *es;
497 	struct inode *inode = file_inode(file);
498 	char pathname[80], *path;
499 
500 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
501 		return;
502 
503 	es = EXT4_SB(inode->i_sb)->s_es;
504 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
505 	if (ext4_error_ratelimit(inode->i_sb)) {
506 		path = file_path(file, pathname, sizeof(pathname));
507 		if (IS_ERR(path))
508 			path = "(unknown)";
509 		va_start(args, fmt);
510 		vaf.fmt = fmt;
511 		vaf.va = &args;
512 		if (block)
513 			printk(KERN_CRIT
514 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
515 			       "block %llu: comm %s: path %s: %pV\n",
516 			       inode->i_sb->s_id, function, line, inode->i_ino,
517 			       block, current->comm, path, &vaf);
518 		else
519 			printk(KERN_CRIT
520 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
521 			       "comm %s: path %s: %pV\n",
522 			       inode->i_sb->s_id, function, line, inode->i_ino,
523 			       current->comm, path, &vaf);
524 		va_end(args);
525 	}
526 	save_error_info(inode->i_sb, function, line);
527 	ext4_handle_error(inode->i_sb);
528 }
529 
530 const char *ext4_decode_error(struct super_block *sb, int errno,
531 			      char nbuf[16])
532 {
533 	char *errstr = NULL;
534 
535 	switch (errno) {
536 	case -EFSCORRUPTED:
537 		errstr = "Corrupt filesystem";
538 		break;
539 	case -EFSBADCRC:
540 		errstr = "Filesystem failed CRC";
541 		break;
542 	case -EIO:
543 		errstr = "IO failure";
544 		break;
545 	case -ENOMEM:
546 		errstr = "Out of memory";
547 		break;
548 	case -EROFS:
549 		if (!sb || (EXT4_SB(sb)->s_journal &&
550 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
551 			errstr = "Journal has aborted";
552 		else
553 			errstr = "Readonly filesystem";
554 		break;
555 	default:
556 		/* If the caller passed in an extra buffer for unknown
557 		 * errors, textualise them now.  Else we just return
558 		 * NULL. */
559 		if (nbuf) {
560 			/* Check for truncated error codes... */
561 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
562 				errstr = nbuf;
563 		}
564 		break;
565 	}
566 
567 	return errstr;
568 }
569 
570 /* __ext4_std_error decodes expected errors from journaling functions
571  * automatically and invokes the appropriate error response.  */
572 
573 void __ext4_std_error(struct super_block *sb, const char *function,
574 		      unsigned int line, int errno)
575 {
576 	char nbuf[16];
577 	const char *errstr;
578 
579 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
580 		return;
581 
582 	/* Special case: if the error is EROFS, and we're not already
583 	 * inside a transaction, then there's really no point in logging
584 	 * an error. */
585 	if (errno == -EROFS && journal_current_handle() == NULL &&
586 	    (sb->s_flags & MS_RDONLY))
587 		return;
588 
589 	if (ext4_error_ratelimit(sb)) {
590 		errstr = ext4_decode_error(sb, errno, nbuf);
591 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
592 		       sb->s_id, function, line, errstr);
593 	}
594 
595 	save_error_info(sb, function, line);
596 	ext4_handle_error(sb);
597 }
598 
599 /*
600  * ext4_abort is a much stronger failure handler than ext4_error.  The
601  * abort function may be used to deal with unrecoverable failures such
602  * as journal IO errors or ENOMEM at a critical moment in log management.
603  *
604  * We unconditionally force the filesystem into an ABORT|READONLY state,
605  * unless the error response on the fs has been set to panic in which
606  * case we take the easy way out and panic immediately.
607  */
608 
609 void __ext4_abort(struct super_block *sb, const char *function,
610 		unsigned int line, const char *fmt, ...)
611 {
612 	struct va_format vaf;
613 	va_list args;
614 
615 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
616 		return;
617 
618 	save_error_info(sb, function, line);
619 	va_start(args, fmt);
620 	vaf.fmt = fmt;
621 	vaf.va = &args;
622 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
623 	       sb->s_id, function, line, &vaf);
624 	va_end(args);
625 
626 	if ((sb->s_flags & MS_RDONLY) == 0) {
627 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
628 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
629 		/*
630 		 * Make sure updated value of ->s_mount_flags will be visible
631 		 * before ->s_flags update
632 		 */
633 		smp_wmb();
634 		sb->s_flags |= MS_RDONLY;
635 		if (EXT4_SB(sb)->s_journal)
636 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
637 		save_error_info(sb, function, line);
638 	}
639 	if (test_opt(sb, ERRORS_PANIC)) {
640 		if (EXT4_SB(sb)->s_journal &&
641 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
642 			return;
643 		panic("EXT4-fs panic from previous error\n");
644 	}
645 }
646 
647 void __ext4_msg(struct super_block *sb,
648 		const char *prefix, const char *fmt, ...)
649 {
650 	struct va_format vaf;
651 	va_list args;
652 
653 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
654 		return;
655 
656 	va_start(args, fmt);
657 	vaf.fmt = fmt;
658 	vaf.va = &args;
659 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
660 	va_end(args);
661 }
662 
663 #define ext4_warning_ratelimit(sb)					\
664 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
665 			     "EXT4-fs warning")
666 
667 void __ext4_warning(struct super_block *sb, const char *function,
668 		    unsigned int line, const char *fmt, ...)
669 {
670 	struct va_format vaf;
671 	va_list args;
672 
673 	if (!ext4_warning_ratelimit(sb))
674 		return;
675 
676 	va_start(args, fmt);
677 	vaf.fmt = fmt;
678 	vaf.va = &args;
679 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
680 	       sb->s_id, function, line, &vaf);
681 	va_end(args);
682 }
683 
684 void __ext4_warning_inode(const struct inode *inode, const char *function,
685 			  unsigned int line, const char *fmt, ...)
686 {
687 	struct va_format vaf;
688 	va_list args;
689 
690 	if (!ext4_warning_ratelimit(inode->i_sb))
691 		return;
692 
693 	va_start(args, fmt);
694 	vaf.fmt = fmt;
695 	vaf.va = &args;
696 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
697 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
698 	       function, line, inode->i_ino, current->comm, &vaf);
699 	va_end(args);
700 }
701 
702 void __ext4_grp_locked_error(const char *function, unsigned int line,
703 			     struct super_block *sb, ext4_group_t grp,
704 			     unsigned long ino, ext4_fsblk_t block,
705 			     const char *fmt, ...)
706 __releases(bitlock)
707 __acquires(bitlock)
708 {
709 	struct va_format vaf;
710 	va_list args;
711 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
712 
713 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
714 		return;
715 
716 	es->s_last_error_ino = cpu_to_le32(ino);
717 	es->s_last_error_block = cpu_to_le64(block);
718 	__save_error_info(sb, function, line);
719 
720 	if (ext4_error_ratelimit(sb)) {
721 		va_start(args, fmt);
722 		vaf.fmt = fmt;
723 		vaf.va = &args;
724 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
725 		       sb->s_id, function, line, grp);
726 		if (ino)
727 			printk(KERN_CONT "inode %lu: ", ino);
728 		if (block)
729 			printk(KERN_CONT "block %llu:",
730 			       (unsigned long long) block);
731 		printk(KERN_CONT "%pV\n", &vaf);
732 		va_end(args);
733 	}
734 
735 	if (test_opt(sb, ERRORS_CONT)) {
736 		ext4_commit_super(sb, 0);
737 		return;
738 	}
739 
740 	ext4_unlock_group(sb, grp);
741 	ext4_handle_error(sb);
742 	/*
743 	 * We only get here in the ERRORS_RO case; relocking the group
744 	 * may be dangerous, but nothing bad will happen since the
745 	 * filesystem will have already been marked read/only and the
746 	 * journal has been aborted.  We return 1 as a hint to callers
747 	 * who might what to use the return value from
748 	 * ext4_grp_locked_error() to distinguish between the
749 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
750 	 * aggressively from the ext4 function in question, with a
751 	 * more appropriate error code.
752 	 */
753 	ext4_lock_group(sb, grp);
754 	return;
755 }
756 
757 void ext4_update_dynamic_rev(struct super_block *sb)
758 {
759 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
760 
761 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
762 		return;
763 
764 	ext4_warning(sb,
765 		     "updating to rev %d because of new feature flag, "
766 		     "running e2fsck is recommended",
767 		     EXT4_DYNAMIC_REV);
768 
769 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
770 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
771 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
772 	/* leave es->s_feature_*compat flags alone */
773 	/* es->s_uuid will be set by e2fsck if empty */
774 
775 	/*
776 	 * The rest of the superblock fields should be zero, and if not it
777 	 * means they are likely already in use, so leave them alone.  We
778 	 * can leave it up to e2fsck to clean up any inconsistencies there.
779 	 */
780 }
781 
782 /*
783  * Open the external journal device
784  */
785 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
786 {
787 	struct block_device *bdev;
788 	char b[BDEVNAME_SIZE];
789 
790 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
791 	if (IS_ERR(bdev))
792 		goto fail;
793 	return bdev;
794 
795 fail:
796 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
797 			__bdevname(dev, b), PTR_ERR(bdev));
798 	return NULL;
799 }
800 
801 /*
802  * Release the journal device
803  */
804 static void ext4_blkdev_put(struct block_device *bdev)
805 {
806 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
807 }
808 
809 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
810 {
811 	struct block_device *bdev;
812 	bdev = sbi->journal_bdev;
813 	if (bdev) {
814 		ext4_blkdev_put(bdev);
815 		sbi->journal_bdev = NULL;
816 	}
817 }
818 
819 static inline struct inode *orphan_list_entry(struct list_head *l)
820 {
821 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
822 }
823 
824 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
825 {
826 	struct list_head *l;
827 
828 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
829 		 le32_to_cpu(sbi->s_es->s_last_orphan));
830 
831 	printk(KERN_ERR "sb_info orphan list:\n");
832 	list_for_each(l, &sbi->s_orphan) {
833 		struct inode *inode = orphan_list_entry(l);
834 		printk(KERN_ERR "  "
835 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
836 		       inode->i_sb->s_id, inode->i_ino, inode,
837 		       inode->i_mode, inode->i_nlink,
838 		       NEXT_ORPHAN(inode));
839 	}
840 }
841 
842 #ifdef CONFIG_QUOTA
843 static int ext4_quota_off(struct super_block *sb, int type);
844 
845 static inline void ext4_quota_off_umount(struct super_block *sb)
846 {
847 	int type;
848 
849 	if (ext4_has_feature_quota(sb)) {
850 		dquot_disable(sb, -1,
851 			      DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
852 	} else {
853 		/* Use our quota_off function to clear inode flags etc. */
854 		for (type = 0; type < EXT4_MAXQUOTAS; type++)
855 			ext4_quota_off(sb, type);
856 	}
857 }
858 #else
859 static inline void ext4_quota_off_umount(struct super_block *sb)
860 {
861 }
862 #endif
863 
864 static void ext4_put_super(struct super_block *sb)
865 {
866 	struct ext4_sb_info *sbi = EXT4_SB(sb);
867 	struct ext4_super_block *es = sbi->s_es;
868 	int aborted = 0;
869 	int i, err;
870 
871 	ext4_unregister_li_request(sb);
872 	ext4_quota_off_umount(sb);
873 
874 	flush_workqueue(sbi->rsv_conversion_wq);
875 	destroy_workqueue(sbi->rsv_conversion_wq);
876 
877 	if (sbi->s_journal) {
878 		aborted = is_journal_aborted(sbi->s_journal);
879 		err = jbd2_journal_destroy(sbi->s_journal);
880 		sbi->s_journal = NULL;
881 		if ((err < 0) && !aborted)
882 			ext4_abort(sb, "Couldn't clean up the journal");
883 	}
884 
885 	ext4_unregister_sysfs(sb);
886 	ext4_es_unregister_shrinker(sbi);
887 	del_timer_sync(&sbi->s_err_report);
888 	ext4_release_system_zone(sb);
889 	ext4_mb_release(sb);
890 	ext4_ext_release(sb);
891 
892 	if (!(sb->s_flags & MS_RDONLY) && !aborted) {
893 		ext4_clear_feature_journal_needs_recovery(sb);
894 		es->s_state = cpu_to_le16(sbi->s_mount_state);
895 	}
896 	if (!(sb->s_flags & MS_RDONLY))
897 		ext4_commit_super(sb, 1);
898 
899 	for (i = 0; i < sbi->s_gdb_count; i++)
900 		brelse(sbi->s_group_desc[i]);
901 	kvfree(sbi->s_group_desc);
902 	kvfree(sbi->s_flex_groups);
903 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
904 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
905 	percpu_counter_destroy(&sbi->s_dirs_counter);
906 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
907 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
908 #ifdef CONFIG_QUOTA
909 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
910 		kfree(sbi->s_qf_names[i]);
911 #endif
912 
913 	/* Debugging code just in case the in-memory inode orphan list
914 	 * isn't empty.  The on-disk one can be non-empty if we've
915 	 * detected an error and taken the fs readonly, but the
916 	 * in-memory list had better be clean by this point. */
917 	if (!list_empty(&sbi->s_orphan))
918 		dump_orphan_list(sb, sbi);
919 	J_ASSERT(list_empty(&sbi->s_orphan));
920 
921 	sync_blockdev(sb->s_bdev);
922 	invalidate_bdev(sb->s_bdev);
923 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
924 		/*
925 		 * Invalidate the journal device's buffers.  We don't want them
926 		 * floating about in memory - the physical journal device may
927 		 * hotswapped, and it breaks the `ro-after' testing code.
928 		 */
929 		sync_blockdev(sbi->journal_bdev);
930 		invalidate_bdev(sbi->journal_bdev);
931 		ext4_blkdev_remove(sbi);
932 	}
933 	if (sbi->s_mb_cache) {
934 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
935 		sbi->s_mb_cache = NULL;
936 	}
937 	if (sbi->s_mmp_tsk)
938 		kthread_stop(sbi->s_mmp_tsk);
939 	brelse(sbi->s_sbh);
940 	sb->s_fs_info = NULL;
941 	/*
942 	 * Now that we are completely done shutting down the
943 	 * superblock, we need to actually destroy the kobject.
944 	 */
945 	kobject_put(&sbi->s_kobj);
946 	wait_for_completion(&sbi->s_kobj_unregister);
947 	if (sbi->s_chksum_driver)
948 		crypto_free_shash(sbi->s_chksum_driver);
949 	kfree(sbi->s_blockgroup_lock);
950 	kfree(sbi);
951 }
952 
953 static struct kmem_cache *ext4_inode_cachep;
954 
955 /*
956  * Called inside transaction, so use GFP_NOFS
957  */
958 static struct inode *ext4_alloc_inode(struct super_block *sb)
959 {
960 	struct ext4_inode_info *ei;
961 
962 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
963 	if (!ei)
964 		return NULL;
965 
966 	ei->vfs_inode.i_version = 1;
967 	spin_lock_init(&ei->i_raw_lock);
968 	INIT_LIST_HEAD(&ei->i_prealloc_list);
969 	spin_lock_init(&ei->i_prealloc_lock);
970 	ext4_es_init_tree(&ei->i_es_tree);
971 	rwlock_init(&ei->i_es_lock);
972 	INIT_LIST_HEAD(&ei->i_es_list);
973 	ei->i_es_all_nr = 0;
974 	ei->i_es_shk_nr = 0;
975 	ei->i_es_shrink_lblk = 0;
976 	ei->i_reserved_data_blocks = 0;
977 	ei->i_reserved_meta_blocks = 0;
978 	ei->i_allocated_meta_blocks = 0;
979 	ei->i_da_metadata_calc_len = 0;
980 	ei->i_da_metadata_calc_last_lblock = 0;
981 	spin_lock_init(&(ei->i_block_reservation_lock));
982 #ifdef CONFIG_QUOTA
983 	ei->i_reserved_quota = 0;
984 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
985 #endif
986 	ei->jinode = NULL;
987 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
988 	spin_lock_init(&ei->i_completed_io_lock);
989 	ei->i_sync_tid = 0;
990 	ei->i_datasync_tid = 0;
991 	atomic_set(&ei->i_unwritten, 0);
992 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
993 	return &ei->vfs_inode;
994 }
995 
996 static int ext4_drop_inode(struct inode *inode)
997 {
998 	int drop = generic_drop_inode(inode);
999 
1000 	trace_ext4_drop_inode(inode, drop);
1001 	return drop;
1002 }
1003 
1004 static void ext4_i_callback(struct rcu_head *head)
1005 {
1006 	struct inode *inode = container_of(head, struct inode, i_rcu);
1007 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1008 }
1009 
1010 static void ext4_destroy_inode(struct inode *inode)
1011 {
1012 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1013 		ext4_msg(inode->i_sb, KERN_ERR,
1014 			 "Inode %lu (%p): orphan list check failed!",
1015 			 inode->i_ino, EXT4_I(inode));
1016 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1017 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1018 				true);
1019 		dump_stack();
1020 	}
1021 	call_rcu(&inode->i_rcu, ext4_i_callback);
1022 }
1023 
1024 static void init_once(void *foo)
1025 {
1026 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1027 
1028 	INIT_LIST_HEAD(&ei->i_orphan);
1029 	init_rwsem(&ei->xattr_sem);
1030 	init_rwsem(&ei->i_data_sem);
1031 	init_rwsem(&ei->i_mmap_sem);
1032 	inode_init_once(&ei->vfs_inode);
1033 }
1034 
1035 static int __init init_inodecache(void)
1036 {
1037 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1038 					     sizeof(struct ext4_inode_info),
1039 					     0, (SLAB_RECLAIM_ACCOUNT|
1040 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1041 					     init_once);
1042 	if (ext4_inode_cachep == NULL)
1043 		return -ENOMEM;
1044 	return 0;
1045 }
1046 
1047 static void destroy_inodecache(void)
1048 {
1049 	/*
1050 	 * Make sure all delayed rcu free inodes are flushed before we
1051 	 * destroy cache.
1052 	 */
1053 	rcu_barrier();
1054 	kmem_cache_destroy(ext4_inode_cachep);
1055 }
1056 
1057 void ext4_clear_inode(struct inode *inode)
1058 {
1059 	invalidate_inode_buffers(inode);
1060 	clear_inode(inode);
1061 	dquot_drop(inode);
1062 	ext4_discard_preallocations(inode);
1063 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1064 	if (EXT4_I(inode)->jinode) {
1065 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1066 					       EXT4_I(inode)->jinode);
1067 		jbd2_free_inode(EXT4_I(inode)->jinode);
1068 		EXT4_I(inode)->jinode = NULL;
1069 	}
1070 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1071 	fscrypt_put_encryption_info(inode, NULL);
1072 #endif
1073 }
1074 
1075 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1076 					u64 ino, u32 generation)
1077 {
1078 	struct inode *inode;
1079 
1080 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1081 		return ERR_PTR(-ESTALE);
1082 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1083 		return ERR_PTR(-ESTALE);
1084 
1085 	/* iget isn't really right if the inode is currently unallocated!!
1086 	 *
1087 	 * ext4_read_inode will return a bad_inode if the inode had been
1088 	 * deleted, so we should be safe.
1089 	 *
1090 	 * Currently we don't know the generation for parent directory, so
1091 	 * a generation of 0 means "accept any"
1092 	 */
1093 	inode = ext4_iget_normal(sb, ino);
1094 	if (IS_ERR(inode))
1095 		return ERR_CAST(inode);
1096 	if (generation && inode->i_generation != generation) {
1097 		iput(inode);
1098 		return ERR_PTR(-ESTALE);
1099 	}
1100 
1101 	return inode;
1102 }
1103 
1104 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1105 					int fh_len, int fh_type)
1106 {
1107 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1108 				    ext4_nfs_get_inode);
1109 }
1110 
1111 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1112 					int fh_len, int fh_type)
1113 {
1114 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1115 				    ext4_nfs_get_inode);
1116 }
1117 
1118 /*
1119  * Try to release metadata pages (indirect blocks, directories) which are
1120  * mapped via the block device.  Since these pages could have journal heads
1121  * which would prevent try_to_free_buffers() from freeing them, we must use
1122  * jbd2 layer's try_to_free_buffers() function to release them.
1123  */
1124 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1125 				 gfp_t wait)
1126 {
1127 	journal_t *journal = EXT4_SB(sb)->s_journal;
1128 
1129 	WARN_ON(PageChecked(page));
1130 	if (!page_has_buffers(page))
1131 		return 0;
1132 	if (journal)
1133 		return jbd2_journal_try_to_free_buffers(journal, page,
1134 						wait & ~__GFP_DIRECT_RECLAIM);
1135 	return try_to_free_buffers(page);
1136 }
1137 
1138 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1139 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1140 {
1141 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1142 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1143 }
1144 
1145 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1146 							void *fs_data)
1147 {
1148 	handle_t *handle = fs_data;
1149 	int res, res2, retries = 0;
1150 
1151 	res = ext4_convert_inline_data(inode);
1152 	if (res)
1153 		return res;
1154 
1155 	/*
1156 	 * If a journal handle was specified, then the encryption context is
1157 	 * being set on a new inode via inheritance and is part of a larger
1158 	 * transaction to create the inode.  Otherwise the encryption context is
1159 	 * being set on an existing inode in its own transaction.  Only in the
1160 	 * latter case should the "retry on ENOSPC" logic be used.
1161 	 */
1162 
1163 	if (handle) {
1164 		res = ext4_xattr_set_handle(handle, inode,
1165 					    EXT4_XATTR_INDEX_ENCRYPTION,
1166 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1167 					    ctx, len, 0);
1168 		if (!res) {
1169 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1170 			ext4_clear_inode_state(inode,
1171 					EXT4_STATE_MAY_INLINE_DATA);
1172 			/*
1173 			 * Update inode->i_flags - e.g. S_DAX may get disabled
1174 			 */
1175 			ext4_set_inode_flags(inode);
1176 		}
1177 		return res;
1178 	}
1179 
1180 retry:
1181 	handle = ext4_journal_start(inode, EXT4_HT_MISC,
1182 			ext4_jbd2_credits_xattr(inode));
1183 	if (IS_ERR(handle))
1184 		return PTR_ERR(handle);
1185 
1186 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1187 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1188 				    ctx, len, 0);
1189 	if (!res) {
1190 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1191 		/* Update inode->i_flags - e.g. S_DAX may get disabled */
1192 		ext4_set_inode_flags(inode);
1193 		res = ext4_mark_inode_dirty(handle, inode);
1194 		if (res)
1195 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1196 	}
1197 	res2 = ext4_journal_stop(handle);
1198 
1199 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1200 		goto retry;
1201 	if (!res)
1202 		res = res2;
1203 	return res;
1204 }
1205 
1206 static int ext4_dummy_context(struct inode *inode)
1207 {
1208 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1209 }
1210 
1211 static unsigned ext4_max_namelen(struct inode *inode)
1212 {
1213 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1214 		EXT4_NAME_LEN;
1215 }
1216 
1217 static const struct fscrypt_operations ext4_cryptops = {
1218 	.key_prefix		= "ext4:",
1219 	.get_context		= ext4_get_context,
1220 	.set_context		= ext4_set_context,
1221 	.dummy_context		= ext4_dummy_context,
1222 	.is_encrypted		= ext4_encrypted_inode,
1223 	.empty_dir		= ext4_empty_dir,
1224 	.max_namelen		= ext4_max_namelen,
1225 };
1226 #else
1227 static const struct fscrypt_operations ext4_cryptops = {
1228 	.is_encrypted		= ext4_encrypted_inode,
1229 };
1230 #endif
1231 
1232 #ifdef CONFIG_QUOTA
1233 static char *quotatypes[] = INITQFNAMES;
1234 #define QTYPE2NAME(t) (quotatypes[t])
1235 
1236 static int ext4_write_dquot(struct dquot *dquot);
1237 static int ext4_acquire_dquot(struct dquot *dquot);
1238 static int ext4_release_dquot(struct dquot *dquot);
1239 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1240 static int ext4_write_info(struct super_block *sb, int type);
1241 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1242 			 const struct path *path);
1243 static int ext4_quota_on_mount(struct super_block *sb, int type);
1244 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1245 			       size_t len, loff_t off);
1246 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1247 				const char *data, size_t len, loff_t off);
1248 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1249 			     unsigned int flags);
1250 static int ext4_enable_quotas(struct super_block *sb);
1251 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1252 
1253 static struct dquot **ext4_get_dquots(struct inode *inode)
1254 {
1255 	return EXT4_I(inode)->i_dquot;
1256 }
1257 
1258 static const struct dquot_operations ext4_quota_operations = {
1259 	.get_reserved_space = ext4_get_reserved_space,
1260 	.write_dquot	= ext4_write_dquot,
1261 	.acquire_dquot	= ext4_acquire_dquot,
1262 	.release_dquot	= ext4_release_dquot,
1263 	.mark_dirty	= ext4_mark_dquot_dirty,
1264 	.write_info	= ext4_write_info,
1265 	.alloc_dquot	= dquot_alloc,
1266 	.destroy_dquot	= dquot_destroy,
1267 	.get_projid	= ext4_get_projid,
1268 	.get_next_id	= ext4_get_next_id,
1269 };
1270 
1271 static const struct quotactl_ops ext4_qctl_operations = {
1272 	.quota_on	= ext4_quota_on,
1273 	.quota_off	= ext4_quota_off,
1274 	.quota_sync	= dquot_quota_sync,
1275 	.get_state	= dquot_get_state,
1276 	.set_info	= dquot_set_dqinfo,
1277 	.get_dqblk	= dquot_get_dqblk,
1278 	.set_dqblk	= dquot_set_dqblk,
1279 	.get_nextdqblk	= dquot_get_next_dqblk,
1280 };
1281 #endif
1282 
1283 static const struct super_operations ext4_sops = {
1284 	.alloc_inode	= ext4_alloc_inode,
1285 	.destroy_inode	= ext4_destroy_inode,
1286 	.write_inode	= ext4_write_inode,
1287 	.dirty_inode	= ext4_dirty_inode,
1288 	.drop_inode	= ext4_drop_inode,
1289 	.evict_inode	= ext4_evict_inode,
1290 	.put_super	= ext4_put_super,
1291 	.sync_fs	= ext4_sync_fs,
1292 	.freeze_fs	= ext4_freeze,
1293 	.unfreeze_fs	= ext4_unfreeze,
1294 	.statfs		= ext4_statfs,
1295 	.remount_fs	= ext4_remount,
1296 	.show_options	= ext4_show_options,
1297 #ifdef CONFIG_QUOTA
1298 	.quota_read	= ext4_quota_read,
1299 	.quota_write	= ext4_quota_write,
1300 	.get_dquots	= ext4_get_dquots,
1301 #endif
1302 	.bdev_try_to_free_page = bdev_try_to_free_page,
1303 };
1304 
1305 static const struct export_operations ext4_export_ops = {
1306 	.fh_to_dentry = ext4_fh_to_dentry,
1307 	.fh_to_parent = ext4_fh_to_parent,
1308 	.get_parent = ext4_get_parent,
1309 };
1310 
1311 enum {
1312 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1313 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1314 	Opt_nouid32, Opt_debug, Opt_removed,
1315 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1316 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1317 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1318 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1319 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1320 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1321 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1322 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1323 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1324 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1325 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1326 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1327 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1328 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1329 	Opt_dioread_nolock, Opt_dioread_lock,
1330 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1331 	Opt_max_dir_size_kb, Opt_nojournal_checksum,
1332 };
1333 
1334 static const match_table_t tokens = {
1335 	{Opt_bsd_df, "bsddf"},
1336 	{Opt_minix_df, "minixdf"},
1337 	{Opt_grpid, "grpid"},
1338 	{Opt_grpid, "bsdgroups"},
1339 	{Opt_nogrpid, "nogrpid"},
1340 	{Opt_nogrpid, "sysvgroups"},
1341 	{Opt_resgid, "resgid=%u"},
1342 	{Opt_resuid, "resuid=%u"},
1343 	{Opt_sb, "sb=%u"},
1344 	{Opt_err_cont, "errors=continue"},
1345 	{Opt_err_panic, "errors=panic"},
1346 	{Opt_err_ro, "errors=remount-ro"},
1347 	{Opt_nouid32, "nouid32"},
1348 	{Opt_debug, "debug"},
1349 	{Opt_removed, "oldalloc"},
1350 	{Opt_removed, "orlov"},
1351 	{Opt_user_xattr, "user_xattr"},
1352 	{Opt_nouser_xattr, "nouser_xattr"},
1353 	{Opt_acl, "acl"},
1354 	{Opt_noacl, "noacl"},
1355 	{Opt_noload, "norecovery"},
1356 	{Opt_noload, "noload"},
1357 	{Opt_removed, "nobh"},
1358 	{Opt_removed, "bh"},
1359 	{Opt_commit, "commit=%u"},
1360 	{Opt_min_batch_time, "min_batch_time=%u"},
1361 	{Opt_max_batch_time, "max_batch_time=%u"},
1362 	{Opt_journal_dev, "journal_dev=%u"},
1363 	{Opt_journal_path, "journal_path=%s"},
1364 	{Opt_journal_checksum, "journal_checksum"},
1365 	{Opt_nojournal_checksum, "nojournal_checksum"},
1366 	{Opt_journal_async_commit, "journal_async_commit"},
1367 	{Opt_abort, "abort"},
1368 	{Opt_data_journal, "data=journal"},
1369 	{Opt_data_ordered, "data=ordered"},
1370 	{Opt_data_writeback, "data=writeback"},
1371 	{Opt_data_err_abort, "data_err=abort"},
1372 	{Opt_data_err_ignore, "data_err=ignore"},
1373 	{Opt_offusrjquota, "usrjquota="},
1374 	{Opt_usrjquota, "usrjquota=%s"},
1375 	{Opt_offgrpjquota, "grpjquota="},
1376 	{Opt_grpjquota, "grpjquota=%s"},
1377 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1378 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1379 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1380 	{Opt_grpquota, "grpquota"},
1381 	{Opt_noquota, "noquota"},
1382 	{Opt_quota, "quota"},
1383 	{Opt_usrquota, "usrquota"},
1384 	{Opt_prjquota, "prjquota"},
1385 	{Opt_barrier, "barrier=%u"},
1386 	{Opt_barrier, "barrier"},
1387 	{Opt_nobarrier, "nobarrier"},
1388 	{Opt_i_version, "i_version"},
1389 	{Opt_dax, "dax"},
1390 	{Opt_stripe, "stripe=%u"},
1391 	{Opt_delalloc, "delalloc"},
1392 	{Opt_lazytime, "lazytime"},
1393 	{Opt_nolazytime, "nolazytime"},
1394 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1395 	{Opt_nodelalloc, "nodelalloc"},
1396 	{Opt_removed, "mblk_io_submit"},
1397 	{Opt_removed, "nomblk_io_submit"},
1398 	{Opt_block_validity, "block_validity"},
1399 	{Opt_noblock_validity, "noblock_validity"},
1400 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1401 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1402 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1403 	{Opt_auto_da_alloc, "auto_da_alloc"},
1404 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1405 	{Opt_dioread_nolock, "dioread_nolock"},
1406 	{Opt_dioread_lock, "dioread_lock"},
1407 	{Opt_discard, "discard"},
1408 	{Opt_nodiscard, "nodiscard"},
1409 	{Opt_init_itable, "init_itable=%u"},
1410 	{Opt_init_itable, "init_itable"},
1411 	{Opt_noinit_itable, "noinit_itable"},
1412 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1413 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1414 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1415 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1416 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1417 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1418 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1419 	{Opt_err, NULL},
1420 };
1421 
1422 static ext4_fsblk_t get_sb_block(void **data)
1423 {
1424 	ext4_fsblk_t	sb_block;
1425 	char		*options = (char *) *data;
1426 
1427 	if (!options || strncmp(options, "sb=", 3) != 0)
1428 		return 1;	/* Default location */
1429 
1430 	options += 3;
1431 	/* TODO: use simple_strtoll with >32bit ext4 */
1432 	sb_block = simple_strtoul(options, &options, 0);
1433 	if (*options && *options != ',') {
1434 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1435 		       (char *) *data);
1436 		return 1;
1437 	}
1438 	if (*options == ',')
1439 		options++;
1440 	*data = (void *) options;
1441 
1442 	return sb_block;
1443 }
1444 
1445 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1446 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1447 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1448 
1449 #ifdef CONFIG_QUOTA
1450 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1451 {
1452 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1453 	char *qname;
1454 	int ret = -1;
1455 
1456 	if (sb_any_quota_loaded(sb) &&
1457 		!sbi->s_qf_names[qtype]) {
1458 		ext4_msg(sb, KERN_ERR,
1459 			"Cannot change journaled "
1460 			"quota options when quota turned on");
1461 		return -1;
1462 	}
1463 	if (ext4_has_feature_quota(sb)) {
1464 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1465 			 "ignored when QUOTA feature is enabled");
1466 		return 1;
1467 	}
1468 	qname = match_strdup(args);
1469 	if (!qname) {
1470 		ext4_msg(sb, KERN_ERR,
1471 			"Not enough memory for storing quotafile name");
1472 		return -1;
1473 	}
1474 	if (sbi->s_qf_names[qtype]) {
1475 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1476 			ret = 1;
1477 		else
1478 			ext4_msg(sb, KERN_ERR,
1479 				 "%s quota file already specified",
1480 				 QTYPE2NAME(qtype));
1481 		goto errout;
1482 	}
1483 	if (strchr(qname, '/')) {
1484 		ext4_msg(sb, KERN_ERR,
1485 			"quotafile must be on filesystem root");
1486 		goto errout;
1487 	}
1488 	sbi->s_qf_names[qtype] = qname;
1489 	set_opt(sb, QUOTA);
1490 	return 1;
1491 errout:
1492 	kfree(qname);
1493 	return ret;
1494 }
1495 
1496 static int clear_qf_name(struct super_block *sb, int qtype)
1497 {
1498 
1499 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1500 
1501 	if (sb_any_quota_loaded(sb) &&
1502 		sbi->s_qf_names[qtype]) {
1503 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1504 			" when quota turned on");
1505 		return -1;
1506 	}
1507 	kfree(sbi->s_qf_names[qtype]);
1508 	sbi->s_qf_names[qtype] = NULL;
1509 	return 1;
1510 }
1511 #endif
1512 
1513 #define MOPT_SET	0x0001
1514 #define MOPT_CLEAR	0x0002
1515 #define MOPT_NOSUPPORT	0x0004
1516 #define MOPT_EXPLICIT	0x0008
1517 #define MOPT_CLEAR_ERR	0x0010
1518 #define MOPT_GTE0	0x0020
1519 #ifdef CONFIG_QUOTA
1520 #define MOPT_Q		0
1521 #define MOPT_QFMT	0x0040
1522 #else
1523 #define MOPT_Q		MOPT_NOSUPPORT
1524 #define MOPT_QFMT	MOPT_NOSUPPORT
1525 #endif
1526 #define MOPT_DATAJ	0x0080
1527 #define MOPT_NO_EXT2	0x0100
1528 #define MOPT_NO_EXT3	0x0200
1529 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1530 #define MOPT_STRING	0x0400
1531 
1532 static const struct mount_opts {
1533 	int	token;
1534 	int	mount_opt;
1535 	int	flags;
1536 } ext4_mount_opts[] = {
1537 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1538 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1539 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1540 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1541 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1542 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1543 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1544 	 MOPT_EXT4_ONLY | MOPT_SET},
1545 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1546 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1547 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1548 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1549 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1550 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1551 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1552 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1553 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1554 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1555 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1556 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1557 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1558 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1559 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1560 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1561 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1562 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1563 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1564 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1565 	 MOPT_NO_EXT2},
1566 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1567 	 MOPT_NO_EXT2},
1568 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1569 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1570 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1571 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1572 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1573 	{Opt_commit, 0, MOPT_GTE0},
1574 	{Opt_max_batch_time, 0, MOPT_GTE0},
1575 	{Opt_min_batch_time, 0, MOPT_GTE0},
1576 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1577 	{Opt_init_itable, 0, MOPT_GTE0},
1578 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1579 	{Opt_stripe, 0, MOPT_GTE0},
1580 	{Opt_resuid, 0, MOPT_GTE0},
1581 	{Opt_resgid, 0, MOPT_GTE0},
1582 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1583 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1584 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1585 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1586 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1587 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1588 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1589 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1590 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1591 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1592 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1593 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1594 #else
1595 	{Opt_acl, 0, MOPT_NOSUPPORT},
1596 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1597 #endif
1598 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1599 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1600 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1601 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1602 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1603 							MOPT_SET | MOPT_Q},
1604 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1605 							MOPT_SET | MOPT_Q},
1606 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1607 							MOPT_SET | MOPT_Q},
1608 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1609 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1610 							MOPT_CLEAR | MOPT_Q},
1611 	{Opt_usrjquota, 0, MOPT_Q},
1612 	{Opt_grpjquota, 0, MOPT_Q},
1613 	{Opt_offusrjquota, 0, MOPT_Q},
1614 	{Opt_offgrpjquota, 0, MOPT_Q},
1615 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1616 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1617 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1618 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1619 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1620 	{Opt_err, 0, 0}
1621 };
1622 
1623 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1624 			    substring_t *args, unsigned long *journal_devnum,
1625 			    unsigned int *journal_ioprio, int is_remount)
1626 {
1627 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1628 	const struct mount_opts *m;
1629 	kuid_t uid;
1630 	kgid_t gid;
1631 	int arg = 0;
1632 
1633 #ifdef CONFIG_QUOTA
1634 	if (token == Opt_usrjquota)
1635 		return set_qf_name(sb, USRQUOTA, &args[0]);
1636 	else if (token == Opt_grpjquota)
1637 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1638 	else if (token == Opt_offusrjquota)
1639 		return clear_qf_name(sb, USRQUOTA);
1640 	else if (token == Opt_offgrpjquota)
1641 		return clear_qf_name(sb, GRPQUOTA);
1642 #endif
1643 	switch (token) {
1644 	case Opt_noacl:
1645 	case Opt_nouser_xattr:
1646 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1647 		break;
1648 	case Opt_sb:
1649 		return 1;	/* handled by get_sb_block() */
1650 	case Opt_removed:
1651 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1652 		return 1;
1653 	case Opt_abort:
1654 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1655 		return 1;
1656 	case Opt_i_version:
1657 		sb->s_flags |= MS_I_VERSION;
1658 		return 1;
1659 	case Opt_lazytime:
1660 		sb->s_flags |= MS_LAZYTIME;
1661 		return 1;
1662 	case Opt_nolazytime:
1663 		sb->s_flags &= ~MS_LAZYTIME;
1664 		return 1;
1665 	}
1666 
1667 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1668 		if (token == m->token)
1669 			break;
1670 
1671 	if (m->token == Opt_err) {
1672 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1673 			 "or missing value", opt);
1674 		return -1;
1675 	}
1676 
1677 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1678 		ext4_msg(sb, KERN_ERR,
1679 			 "Mount option \"%s\" incompatible with ext2", opt);
1680 		return -1;
1681 	}
1682 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1683 		ext4_msg(sb, KERN_ERR,
1684 			 "Mount option \"%s\" incompatible with ext3", opt);
1685 		return -1;
1686 	}
1687 
1688 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1689 		return -1;
1690 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1691 		return -1;
1692 	if (m->flags & MOPT_EXPLICIT) {
1693 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1694 			set_opt2(sb, EXPLICIT_DELALLOC);
1695 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1696 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1697 		} else
1698 			return -1;
1699 	}
1700 	if (m->flags & MOPT_CLEAR_ERR)
1701 		clear_opt(sb, ERRORS_MASK);
1702 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1703 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1704 			 "options when quota turned on");
1705 		return -1;
1706 	}
1707 
1708 	if (m->flags & MOPT_NOSUPPORT) {
1709 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1710 	} else if (token == Opt_commit) {
1711 		if (arg == 0)
1712 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1713 		sbi->s_commit_interval = HZ * arg;
1714 	} else if (token == Opt_debug_want_extra_isize) {
1715 		sbi->s_want_extra_isize = arg;
1716 	} else if (token == Opt_max_batch_time) {
1717 		sbi->s_max_batch_time = arg;
1718 	} else if (token == Opt_min_batch_time) {
1719 		sbi->s_min_batch_time = arg;
1720 	} else if (token == Opt_inode_readahead_blks) {
1721 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1722 			ext4_msg(sb, KERN_ERR,
1723 				 "EXT4-fs: inode_readahead_blks must be "
1724 				 "0 or a power of 2 smaller than 2^31");
1725 			return -1;
1726 		}
1727 		sbi->s_inode_readahead_blks = arg;
1728 	} else if (token == Opt_init_itable) {
1729 		set_opt(sb, INIT_INODE_TABLE);
1730 		if (!args->from)
1731 			arg = EXT4_DEF_LI_WAIT_MULT;
1732 		sbi->s_li_wait_mult = arg;
1733 	} else if (token == Opt_max_dir_size_kb) {
1734 		sbi->s_max_dir_size_kb = arg;
1735 	} else if (token == Opt_stripe) {
1736 		sbi->s_stripe = arg;
1737 	} else if (token == Opt_resuid) {
1738 		uid = make_kuid(current_user_ns(), arg);
1739 		if (!uid_valid(uid)) {
1740 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1741 			return -1;
1742 		}
1743 		sbi->s_resuid = uid;
1744 	} else if (token == Opt_resgid) {
1745 		gid = make_kgid(current_user_ns(), arg);
1746 		if (!gid_valid(gid)) {
1747 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1748 			return -1;
1749 		}
1750 		sbi->s_resgid = gid;
1751 	} else if (token == Opt_journal_dev) {
1752 		if (is_remount) {
1753 			ext4_msg(sb, KERN_ERR,
1754 				 "Cannot specify journal on remount");
1755 			return -1;
1756 		}
1757 		*journal_devnum = arg;
1758 	} else if (token == Opt_journal_path) {
1759 		char *journal_path;
1760 		struct inode *journal_inode;
1761 		struct path path;
1762 		int error;
1763 
1764 		if (is_remount) {
1765 			ext4_msg(sb, KERN_ERR,
1766 				 "Cannot specify journal on remount");
1767 			return -1;
1768 		}
1769 		journal_path = match_strdup(&args[0]);
1770 		if (!journal_path) {
1771 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1772 				"journal device string");
1773 			return -1;
1774 		}
1775 
1776 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1777 		if (error) {
1778 			ext4_msg(sb, KERN_ERR, "error: could not find "
1779 				"journal device path: error %d", error);
1780 			kfree(journal_path);
1781 			return -1;
1782 		}
1783 
1784 		journal_inode = d_inode(path.dentry);
1785 		if (!S_ISBLK(journal_inode->i_mode)) {
1786 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1787 				"is not a block device", journal_path);
1788 			path_put(&path);
1789 			kfree(journal_path);
1790 			return -1;
1791 		}
1792 
1793 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1794 		path_put(&path);
1795 		kfree(journal_path);
1796 	} else if (token == Opt_journal_ioprio) {
1797 		if (arg > 7) {
1798 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1799 				 " (must be 0-7)");
1800 			return -1;
1801 		}
1802 		*journal_ioprio =
1803 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1804 	} else if (token == Opt_test_dummy_encryption) {
1805 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1806 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1807 		ext4_msg(sb, KERN_WARNING,
1808 			 "Test dummy encryption mode enabled");
1809 #else
1810 		ext4_msg(sb, KERN_WARNING,
1811 			 "Test dummy encryption mount option ignored");
1812 #endif
1813 	} else if (m->flags & MOPT_DATAJ) {
1814 		if (is_remount) {
1815 			if (!sbi->s_journal)
1816 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1817 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1818 				ext4_msg(sb, KERN_ERR,
1819 					 "Cannot change data mode on remount");
1820 				return -1;
1821 			}
1822 		} else {
1823 			clear_opt(sb, DATA_FLAGS);
1824 			sbi->s_mount_opt |= m->mount_opt;
1825 		}
1826 #ifdef CONFIG_QUOTA
1827 	} else if (m->flags & MOPT_QFMT) {
1828 		if (sb_any_quota_loaded(sb) &&
1829 		    sbi->s_jquota_fmt != m->mount_opt) {
1830 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1831 				 "quota options when quota turned on");
1832 			return -1;
1833 		}
1834 		if (ext4_has_feature_quota(sb)) {
1835 			ext4_msg(sb, KERN_INFO,
1836 				 "Quota format mount options ignored "
1837 				 "when QUOTA feature is enabled");
1838 			return 1;
1839 		}
1840 		sbi->s_jquota_fmt = m->mount_opt;
1841 #endif
1842 	} else if (token == Opt_dax) {
1843 #ifdef CONFIG_FS_DAX
1844 		ext4_msg(sb, KERN_WARNING,
1845 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1846 			sbi->s_mount_opt |= m->mount_opt;
1847 #else
1848 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1849 		return -1;
1850 #endif
1851 	} else if (token == Opt_data_err_abort) {
1852 		sbi->s_mount_opt |= m->mount_opt;
1853 	} else if (token == Opt_data_err_ignore) {
1854 		sbi->s_mount_opt &= ~m->mount_opt;
1855 	} else {
1856 		if (!args->from)
1857 			arg = 1;
1858 		if (m->flags & MOPT_CLEAR)
1859 			arg = !arg;
1860 		else if (unlikely(!(m->flags & MOPT_SET))) {
1861 			ext4_msg(sb, KERN_WARNING,
1862 				 "buggy handling of option %s", opt);
1863 			WARN_ON(1);
1864 			return -1;
1865 		}
1866 		if (arg != 0)
1867 			sbi->s_mount_opt |= m->mount_opt;
1868 		else
1869 			sbi->s_mount_opt &= ~m->mount_opt;
1870 	}
1871 	return 1;
1872 }
1873 
1874 static int parse_options(char *options, struct super_block *sb,
1875 			 unsigned long *journal_devnum,
1876 			 unsigned int *journal_ioprio,
1877 			 int is_remount)
1878 {
1879 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1880 	char *p;
1881 	substring_t args[MAX_OPT_ARGS];
1882 	int token;
1883 
1884 	if (!options)
1885 		return 1;
1886 
1887 	while ((p = strsep(&options, ",")) != NULL) {
1888 		if (!*p)
1889 			continue;
1890 		/*
1891 		 * Initialize args struct so we know whether arg was
1892 		 * found; some options take optional arguments.
1893 		 */
1894 		args[0].to = args[0].from = NULL;
1895 		token = match_token(p, tokens, args);
1896 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1897 				     journal_ioprio, is_remount) < 0)
1898 			return 0;
1899 	}
1900 #ifdef CONFIG_QUOTA
1901 	/*
1902 	 * We do the test below only for project quotas. 'usrquota' and
1903 	 * 'grpquota' mount options are allowed even without quota feature
1904 	 * to support legacy quotas in quota files.
1905 	 */
1906 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1907 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1908 			 "Cannot enable project quota enforcement.");
1909 		return 0;
1910 	}
1911 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1912 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1913 			clear_opt(sb, USRQUOTA);
1914 
1915 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1916 			clear_opt(sb, GRPQUOTA);
1917 
1918 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1919 			ext4_msg(sb, KERN_ERR, "old and new quota "
1920 					"format mixing");
1921 			return 0;
1922 		}
1923 
1924 		if (!sbi->s_jquota_fmt) {
1925 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1926 					"not specified");
1927 			return 0;
1928 		}
1929 	}
1930 #endif
1931 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1932 		int blocksize =
1933 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1934 
1935 		if (blocksize < PAGE_SIZE) {
1936 			ext4_msg(sb, KERN_ERR, "can't mount with "
1937 				 "dioread_nolock if block size != PAGE_SIZE");
1938 			return 0;
1939 		}
1940 	}
1941 	return 1;
1942 }
1943 
1944 static inline void ext4_show_quota_options(struct seq_file *seq,
1945 					   struct super_block *sb)
1946 {
1947 #if defined(CONFIG_QUOTA)
1948 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1949 
1950 	if (sbi->s_jquota_fmt) {
1951 		char *fmtname = "";
1952 
1953 		switch (sbi->s_jquota_fmt) {
1954 		case QFMT_VFS_OLD:
1955 			fmtname = "vfsold";
1956 			break;
1957 		case QFMT_VFS_V0:
1958 			fmtname = "vfsv0";
1959 			break;
1960 		case QFMT_VFS_V1:
1961 			fmtname = "vfsv1";
1962 			break;
1963 		}
1964 		seq_printf(seq, ",jqfmt=%s", fmtname);
1965 	}
1966 
1967 	if (sbi->s_qf_names[USRQUOTA])
1968 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1969 
1970 	if (sbi->s_qf_names[GRPQUOTA])
1971 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1972 #endif
1973 }
1974 
1975 static const char *token2str(int token)
1976 {
1977 	const struct match_token *t;
1978 
1979 	for (t = tokens; t->token != Opt_err; t++)
1980 		if (t->token == token && !strchr(t->pattern, '='))
1981 			break;
1982 	return t->pattern;
1983 }
1984 
1985 /*
1986  * Show an option if
1987  *  - it's set to a non-default value OR
1988  *  - if the per-sb default is different from the global default
1989  */
1990 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1991 			      int nodefs)
1992 {
1993 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1994 	struct ext4_super_block *es = sbi->s_es;
1995 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1996 	const struct mount_opts *m;
1997 	char sep = nodefs ? '\n' : ',';
1998 
1999 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2000 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2001 
2002 	if (sbi->s_sb_block != 1)
2003 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2004 
2005 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2006 		int want_set = m->flags & MOPT_SET;
2007 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2008 		    (m->flags & MOPT_CLEAR_ERR))
2009 			continue;
2010 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2011 			continue; /* skip if same as the default */
2012 		if ((want_set &&
2013 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2014 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2015 			continue; /* select Opt_noFoo vs Opt_Foo */
2016 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2017 	}
2018 
2019 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2020 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2021 		SEQ_OPTS_PRINT("resuid=%u",
2022 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2023 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2024 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2025 		SEQ_OPTS_PRINT("resgid=%u",
2026 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2027 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2028 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2029 		SEQ_OPTS_PUTS("errors=remount-ro");
2030 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2031 		SEQ_OPTS_PUTS("errors=continue");
2032 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2033 		SEQ_OPTS_PUTS("errors=panic");
2034 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2035 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2036 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2037 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2038 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2039 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2040 	if (sb->s_flags & MS_I_VERSION)
2041 		SEQ_OPTS_PUTS("i_version");
2042 	if (nodefs || sbi->s_stripe)
2043 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2044 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2045 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2046 			SEQ_OPTS_PUTS("data=journal");
2047 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2048 			SEQ_OPTS_PUTS("data=ordered");
2049 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2050 			SEQ_OPTS_PUTS("data=writeback");
2051 	}
2052 	if (nodefs ||
2053 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2054 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2055 			       sbi->s_inode_readahead_blks);
2056 
2057 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2058 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2059 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2060 	if (nodefs || sbi->s_max_dir_size_kb)
2061 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2062 	if (test_opt(sb, DATA_ERR_ABORT))
2063 		SEQ_OPTS_PUTS("data_err=abort");
2064 
2065 	ext4_show_quota_options(seq, sb);
2066 	return 0;
2067 }
2068 
2069 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2070 {
2071 	return _ext4_show_options(seq, root->d_sb, 0);
2072 }
2073 
2074 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2075 {
2076 	struct super_block *sb = seq->private;
2077 	int rc;
2078 
2079 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2080 	rc = _ext4_show_options(seq, sb, 1);
2081 	seq_puts(seq, "\n");
2082 	return rc;
2083 }
2084 
2085 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2086 			    int read_only)
2087 {
2088 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2089 	int res = 0;
2090 
2091 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2092 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2093 			 "forcing read-only mode");
2094 		res = MS_RDONLY;
2095 	}
2096 	if (read_only)
2097 		goto done;
2098 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2099 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2100 			 "running e2fsck is recommended");
2101 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2102 		ext4_msg(sb, KERN_WARNING,
2103 			 "warning: mounting fs with errors, "
2104 			 "running e2fsck is recommended");
2105 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2106 		 le16_to_cpu(es->s_mnt_count) >=
2107 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2108 		ext4_msg(sb, KERN_WARNING,
2109 			 "warning: maximal mount count reached, "
2110 			 "running e2fsck is recommended");
2111 	else if (le32_to_cpu(es->s_checkinterval) &&
2112 		(le32_to_cpu(es->s_lastcheck) +
2113 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2114 		ext4_msg(sb, KERN_WARNING,
2115 			 "warning: checktime reached, "
2116 			 "running e2fsck is recommended");
2117 	if (!sbi->s_journal)
2118 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2119 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2120 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2121 	le16_add_cpu(&es->s_mnt_count, 1);
2122 	es->s_mtime = cpu_to_le32(get_seconds());
2123 	ext4_update_dynamic_rev(sb);
2124 	if (sbi->s_journal)
2125 		ext4_set_feature_journal_needs_recovery(sb);
2126 
2127 	ext4_commit_super(sb, 1);
2128 done:
2129 	if (test_opt(sb, DEBUG))
2130 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2131 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2132 			sb->s_blocksize,
2133 			sbi->s_groups_count,
2134 			EXT4_BLOCKS_PER_GROUP(sb),
2135 			EXT4_INODES_PER_GROUP(sb),
2136 			sbi->s_mount_opt, sbi->s_mount_opt2);
2137 
2138 	cleancache_init_fs(sb);
2139 	return res;
2140 }
2141 
2142 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2143 {
2144 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2145 	struct flex_groups *new_groups;
2146 	int size;
2147 
2148 	if (!sbi->s_log_groups_per_flex)
2149 		return 0;
2150 
2151 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2152 	if (size <= sbi->s_flex_groups_allocated)
2153 		return 0;
2154 
2155 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2156 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
2157 	if (!new_groups) {
2158 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2159 			 size / (int) sizeof(struct flex_groups));
2160 		return -ENOMEM;
2161 	}
2162 
2163 	if (sbi->s_flex_groups) {
2164 		memcpy(new_groups, sbi->s_flex_groups,
2165 		       (sbi->s_flex_groups_allocated *
2166 			sizeof(struct flex_groups)));
2167 		kvfree(sbi->s_flex_groups);
2168 	}
2169 	sbi->s_flex_groups = new_groups;
2170 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2171 	return 0;
2172 }
2173 
2174 static int ext4_fill_flex_info(struct super_block *sb)
2175 {
2176 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2177 	struct ext4_group_desc *gdp = NULL;
2178 	ext4_group_t flex_group;
2179 	int i, err;
2180 
2181 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2182 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2183 		sbi->s_log_groups_per_flex = 0;
2184 		return 1;
2185 	}
2186 
2187 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2188 	if (err)
2189 		goto failed;
2190 
2191 	for (i = 0; i < sbi->s_groups_count; i++) {
2192 		gdp = ext4_get_group_desc(sb, i, NULL);
2193 
2194 		flex_group = ext4_flex_group(sbi, i);
2195 		atomic_add(ext4_free_inodes_count(sb, gdp),
2196 			   &sbi->s_flex_groups[flex_group].free_inodes);
2197 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2198 			     &sbi->s_flex_groups[flex_group].free_clusters);
2199 		atomic_add(ext4_used_dirs_count(sb, gdp),
2200 			   &sbi->s_flex_groups[flex_group].used_dirs);
2201 	}
2202 
2203 	return 1;
2204 failed:
2205 	return 0;
2206 }
2207 
2208 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2209 				   struct ext4_group_desc *gdp)
2210 {
2211 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2212 	__u16 crc = 0;
2213 	__le32 le_group = cpu_to_le32(block_group);
2214 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2215 
2216 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2217 		/* Use new metadata_csum algorithm */
2218 		__u32 csum32;
2219 		__u16 dummy_csum = 0;
2220 
2221 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2222 				     sizeof(le_group));
2223 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2224 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2225 				     sizeof(dummy_csum));
2226 		offset += sizeof(dummy_csum);
2227 		if (offset < sbi->s_desc_size)
2228 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2229 					     sbi->s_desc_size - offset);
2230 
2231 		crc = csum32 & 0xFFFF;
2232 		goto out;
2233 	}
2234 
2235 	/* old crc16 code */
2236 	if (!ext4_has_feature_gdt_csum(sb))
2237 		return 0;
2238 
2239 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2240 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2241 	crc = crc16(crc, (__u8 *)gdp, offset);
2242 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2243 	/* for checksum of struct ext4_group_desc do the rest...*/
2244 	if (ext4_has_feature_64bit(sb) &&
2245 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2246 		crc = crc16(crc, (__u8 *)gdp + offset,
2247 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2248 				offset);
2249 
2250 out:
2251 	return cpu_to_le16(crc);
2252 }
2253 
2254 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2255 				struct ext4_group_desc *gdp)
2256 {
2257 	if (ext4_has_group_desc_csum(sb) &&
2258 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2259 		return 0;
2260 
2261 	return 1;
2262 }
2263 
2264 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2265 			      struct ext4_group_desc *gdp)
2266 {
2267 	if (!ext4_has_group_desc_csum(sb))
2268 		return;
2269 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2270 }
2271 
2272 /* Called at mount-time, super-block is locked */
2273 static int ext4_check_descriptors(struct super_block *sb,
2274 				  ext4_fsblk_t sb_block,
2275 				  ext4_group_t *first_not_zeroed)
2276 {
2277 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2278 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2279 	ext4_fsblk_t last_block;
2280 	ext4_fsblk_t block_bitmap;
2281 	ext4_fsblk_t inode_bitmap;
2282 	ext4_fsblk_t inode_table;
2283 	int flexbg_flag = 0;
2284 	ext4_group_t i, grp = sbi->s_groups_count;
2285 
2286 	if (ext4_has_feature_flex_bg(sb))
2287 		flexbg_flag = 1;
2288 
2289 	ext4_debug("Checking group descriptors");
2290 
2291 	for (i = 0; i < sbi->s_groups_count; i++) {
2292 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2293 
2294 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2295 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2296 		else
2297 			last_block = first_block +
2298 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2299 
2300 		if ((grp == sbi->s_groups_count) &&
2301 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2302 			grp = i;
2303 
2304 		block_bitmap = ext4_block_bitmap(sb, gdp);
2305 		if (block_bitmap == sb_block) {
2306 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2307 				 "Block bitmap for group %u overlaps "
2308 				 "superblock", i);
2309 		}
2310 		if (block_bitmap < first_block || block_bitmap > last_block) {
2311 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2312 			       "Block bitmap for group %u not in group "
2313 			       "(block %llu)!", i, block_bitmap);
2314 			return 0;
2315 		}
2316 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2317 		if (inode_bitmap == sb_block) {
2318 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2319 				 "Inode bitmap for group %u overlaps "
2320 				 "superblock", i);
2321 		}
2322 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2323 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2324 			       "Inode bitmap for group %u not in group "
2325 			       "(block %llu)!", i, inode_bitmap);
2326 			return 0;
2327 		}
2328 		inode_table = ext4_inode_table(sb, gdp);
2329 		if (inode_table == sb_block) {
2330 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2331 				 "Inode table for group %u overlaps "
2332 				 "superblock", i);
2333 		}
2334 		if (inode_table < first_block ||
2335 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2336 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2337 			       "Inode table for group %u not in group "
2338 			       "(block %llu)!", i, inode_table);
2339 			return 0;
2340 		}
2341 		ext4_lock_group(sb, i);
2342 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2343 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2344 				 "Checksum for group %u failed (%u!=%u)",
2345 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2346 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2347 			if (!(sb->s_flags & MS_RDONLY)) {
2348 				ext4_unlock_group(sb, i);
2349 				return 0;
2350 			}
2351 		}
2352 		ext4_unlock_group(sb, i);
2353 		if (!flexbg_flag)
2354 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2355 	}
2356 	if (NULL != first_not_zeroed)
2357 		*first_not_zeroed = grp;
2358 	return 1;
2359 }
2360 
2361 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2362  * the superblock) which were deleted from all directories, but held open by
2363  * a process at the time of a crash.  We walk the list and try to delete these
2364  * inodes at recovery time (only with a read-write filesystem).
2365  *
2366  * In order to keep the orphan inode chain consistent during traversal (in
2367  * case of crash during recovery), we link each inode into the superblock
2368  * orphan list_head and handle it the same way as an inode deletion during
2369  * normal operation (which journals the operations for us).
2370  *
2371  * We only do an iget() and an iput() on each inode, which is very safe if we
2372  * accidentally point at an in-use or already deleted inode.  The worst that
2373  * can happen in this case is that we get a "bit already cleared" message from
2374  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2375  * e2fsck was run on this filesystem, and it must have already done the orphan
2376  * inode cleanup for us, so we can safely abort without any further action.
2377  */
2378 static void ext4_orphan_cleanup(struct super_block *sb,
2379 				struct ext4_super_block *es)
2380 {
2381 	unsigned int s_flags = sb->s_flags;
2382 	int ret, nr_orphans = 0, nr_truncates = 0;
2383 #ifdef CONFIG_QUOTA
2384 	int i;
2385 #endif
2386 	if (!es->s_last_orphan) {
2387 		jbd_debug(4, "no orphan inodes to clean up\n");
2388 		return;
2389 	}
2390 
2391 	if (bdev_read_only(sb->s_bdev)) {
2392 		ext4_msg(sb, KERN_ERR, "write access "
2393 			"unavailable, skipping orphan cleanup");
2394 		return;
2395 	}
2396 
2397 	/* Check if feature set would not allow a r/w mount */
2398 	if (!ext4_feature_set_ok(sb, 0)) {
2399 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2400 			 "unknown ROCOMPAT features");
2401 		return;
2402 	}
2403 
2404 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2405 		/* don't clear list on RO mount w/ errors */
2406 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2407 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2408 				  "clearing orphan list.\n");
2409 			es->s_last_orphan = 0;
2410 		}
2411 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2412 		return;
2413 	}
2414 
2415 	if (s_flags & MS_RDONLY) {
2416 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2417 		sb->s_flags &= ~MS_RDONLY;
2418 	}
2419 #ifdef CONFIG_QUOTA
2420 	/* Needed for iput() to work correctly and not trash data */
2421 	sb->s_flags |= MS_ACTIVE;
2422 	/* Turn on quotas so that they are updated correctly */
2423 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2424 		if (EXT4_SB(sb)->s_qf_names[i]) {
2425 			int ret = ext4_quota_on_mount(sb, i);
2426 			if (ret < 0)
2427 				ext4_msg(sb, KERN_ERR,
2428 					"Cannot turn on journaled "
2429 					"quota: error %d", ret);
2430 		}
2431 	}
2432 #endif
2433 
2434 	while (es->s_last_orphan) {
2435 		struct inode *inode;
2436 
2437 		/*
2438 		 * We may have encountered an error during cleanup; if
2439 		 * so, skip the rest.
2440 		 */
2441 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2442 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2443 			es->s_last_orphan = 0;
2444 			break;
2445 		}
2446 
2447 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2448 		if (IS_ERR(inode)) {
2449 			es->s_last_orphan = 0;
2450 			break;
2451 		}
2452 
2453 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2454 		dquot_initialize(inode);
2455 		if (inode->i_nlink) {
2456 			if (test_opt(sb, DEBUG))
2457 				ext4_msg(sb, KERN_DEBUG,
2458 					"%s: truncating inode %lu to %lld bytes",
2459 					__func__, inode->i_ino, inode->i_size);
2460 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2461 				  inode->i_ino, inode->i_size);
2462 			inode_lock(inode);
2463 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2464 			ret = ext4_truncate(inode);
2465 			if (ret)
2466 				ext4_std_error(inode->i_sb, ret);
2467 			inode_unlock(inode);
2468 			nr_truncates++;
2469 		} else {
2470 			if (test_opt(sb, DEBUG))
2471 				ext4_msg(sb, KERN_DEBUG,
2472 					"%s: deleting unreferenced inode %lu",
2473 					__func__, inode->i_ino);
2474 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2475 				  inode->i_ino);
2476 			nr_orphans++;
2477 		}
2478 		iput(inode);  /* The delete magic happens here! */
2479 	}
2480 
2481 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2482 
2483 	if (nr_orphans)
2484 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2485 		       PLURAL(nr_orphans));
2486 	if (nr_truncates)
2487 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2488 		       PLURAL(nr_truncates));
2489 #ifdef CONFIG_QUOTA
2490 	/* Turn quotas off */
2491 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2492 		if (sb_dqopt(sb)->files[i])
2493 			dquot_quota_off(sb, i);
2494 	}
2495 #endif
2496 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2497 }
2498 
2499 /*
2500  * Maximal extent format file size.
2501  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2502  * extent format containers, within a sector_t, and within i_blocks
2503  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2504  * so that won't be a limiting factor.
2505  *
2506  * However there is other limiting factor. We do store extents in the form
2507  * of starting block and length, hence the resulting length of the extent
2508  * covering maximum file size must fit into on-disk format containers as
2509  * well. Given that length is always by 1 unit bigger than max unit (because
2510  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2511  *
2512  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2513  */
2514 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2515 {
2516 	loff_t res;
2517 	loff_t upper_limit = MAX_LFS_FILESIZE;
2518 
2519 	/* small i_blocks in vfs inode? */
2520 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2521 		/*
2522 		 * CONFIG_LBDAF is not enabled implies the inode
2523 		 * i_block represent total blocks in 512 bytes
2524 		 * 32 == size of vfs inode i_blocks * 8
2525 		 */
2526 		upper_limit = (1LL << 32) - 1;
2527 
2528 		/* total blocks in file system block size */
2529 		upper_limit >>= (blkbits - 9);
2530 		upper_limit <<= blkbits;
2531 	}
2532 
2533 	/*
2534 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2535 	 * by one fs block, so ee_len can cover the extent of maximum file
2536 	 * size
2537 	 */
2538 	res = (1LL << 32) - 1;
2539 	res <<= blkbits;
2540 
2541 	/* Sanity check against vm- & vfs- imposed limits */
2542 	if (res > upper_limit)
2543 		res = upper_limit;
2544 
2545 	return res;
2546 }
2547 
2548 /*
2549  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2550  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2551  * We need to be 1 filesystem block less than the 2^48 sector limit.
2552  */
2553 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2554 {
2555 	loff_t res = EXT4_NDIR_BLOCKS;
2556 	int meta_blocks;
2557 	loff_t upper_limit;
2558 	/* This is calculated to be the largest file size for a dense, block
2559 	 * mapped file such that the file's total number of 512-byte sectors,
2560 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2561 	 *
2562 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2563 	 * number of 512-byte sectors of the file.
2564 	 */
2565 
2566 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2567 		/*
2568 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2569 		 * the inode i_block field represents total file blocks in
2570 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2571 		 */
2572 		upper_limit = (1LL << 32) - 1;
2573 
2574 		/* total blocks in file system block size */
2575 		upper_limit >>= (bits - 9);
2576 
2577 	} else {
2578 		/*
2579 		 * We use 48 bit ext4_inode i_blocks
2580 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2581 		 * represent total number of blocks in
2582 		 * file system block size
2583 		 */
2584 		upper_limit = (1LL << 48) - 1;
2585 
2586 	}
2587 
2588 	/* indirect blocks */
2589 	meta_blocks = 1;
2590 	/* double indirect blocks */
2591 	meta_blocks += 1 + (1LL << (bits-2));
2592 	/* tripple indirect blocks */
2593 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2594 
2595 	upper_limit -= meta_blocks;
2596 	upper_limit <<= bits;
2597 
2598 	res += 1LL << (bits-2);
2599 	res += 1LL << (2*(bits-2));
2600 	res += 1LL << (3*(bits-2));
2601 	res <<= bits;
2602 	if (res > upper_limit)
2603 		res = upper_limit;
2604 
2605 	if (res > MAX_LFS_FILESIZE)
2606 		res = MAX_LFS_FILESIZE;
2607 
2608 	return res;
2609 }
2610 
2611 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2612 				   ext4_fsblk_t logical_sb_block, int nr)
2613 {
2614 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2615 	ext4_group_t bg, first_meta_bg;
2616 	int has_super = 0;
2617 
2618 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2619 
2620 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2621 		return logical_sb_block + nr + 1;
2622 	bg = sbi->s_desc_per_block * nr;
2623 	if (ext4_bg_has_super(sb, bg))
2624 		has_super = 1;
2625 
2626 	/*
2627 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2628 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2629 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2630 	 * compensate.
2631 	 */
2632 	if (sb->s_blocksize == 1024 && nr == 0 &&
2633 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2634 		has_super++;
2635 
2636 	return (has_super + ext4_group_first_block_no(sb, bg));
2637 }
2638 
2639 /**
2640  * ext4_get_stripe_size: Get the stripe size.
2641  * @sbi: In memory super block info
2642  *
2643  * If we have specified it via mount option, then
2644  * use the mount option value. If the value specified at mount time is
2645  * greater than the blocks per group use the super block value.
2646  * If the super block value is greater than blocks per group return 0.
2647  * Allocator needs it be less than blocks per group.
2648  *
2649  */
2650 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2651 {
2652 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2653 	unsigned long stripe_width =
2654 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2655 	int ret;
2656 
2657 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2658 		ret = sbi->s_stripe;
2659 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2660 		ret = stripe_width;
2661 	else if (stride && stride <= sbi->s_blocks_per_group)
2662 		ret = stride;
2663 	else
2664 		ret = 0;
2665 
2666 	/*
2667 	 * If the stripe width is 1, this makes no sense and
2668 	 * we set it to 0 to turn off stripe handling code.
2669 	 */
2670 	if (ret <= 1)
2671 		ret = 0;
2672 
2673 	return ret;
2674 }
2675 
2676 /*
2677  * Check whether this filesystem can be mounted based on
2678  * the features present and the RDONLY/RDWR mount requested.
2679  * Returns 1 if this filesystem can be mounted as requested,
2680  * 0 if it cannot be.
2681  */
2682 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2683 {
2684 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2685 		ext4_msg(sb, KERN_ERR,
2686 			"Couldn't mount because of "
2687 			"unsupported optional features (%x)",
2688 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2689 			~EXT4_FEATURE_INCOMPAT_SUPP));
2690 		return 0;
2691 	}
2692 
2693 	if (readonly)
2694 		return 1;
2695 
2696 	if (ext4_has_feature_readonly(sb)) {
2697 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2698 		sb->s_flags |= MS_RDONLY;
2699 		return 1;
2700 	}
2701 
2702 	/* Check that feature set is OK for a read-write mount */
2703 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2704 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2705 			 "unsupported optional features (%x)",
2706 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2707 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2708 		return 0;
2709 	}
2710 	/*
2711 	 * Large file size enabled file system can only be mounted
2712 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2713 	 */
2714 	if (ext4_has_feature_huge_file(sb)) {
2715 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2716 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2717 				 "cannot be mounted RDWR without "
2718 				 "CONFIG_LBDAF");
2719 			return 0;
2720 		}
2721 	}
2722 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2723 		ext4_msg(sb, KERN_ERR,
2724 			 "Can't support bigalloc feature without "
2725 			 "extents feature\n");
2726 		return 0;
2727 	}
2728 
2729 #ifndef CONFIG_QUOTA
2730 	if (ext4_has_feature_quota(sb) && !readonly) {
2731 		ext4_msg(sb, KERN_ERR,
2732 			 "Filesystem with quota feature cannot be mounted RDWR "
2733 			 "without CONFIG_QUOTA");
2734 		return 0;
2735 	}
2736 	if (ext4_has_feature_project(sb) && !readonly) {
2737 		ext4_msg(sb, KERN_ERR,
2738 			 "Filesystem with project quota feature cannot be mounted RDWR "
2739 			 "without CONFIG_QUOTA");
2740 		return 0;
2741 	}
2742 #endif  /* CONFIG_QUOTA */
2743 	return 1;
2744 }
2745 
2746 /*
2747  * This function is called once a day if we have errors logged
2748  * on the file system
2749  */
2750 static void print_daily_error_info(unsigned long arg)
2751 {
2752 	struct super_block *sb = (struct super_block *) arg;
2753 	struct ext4_sb_info *sbi;
2754 	struct ext4_super_block *es;
2755 
2756 	sbi = EXT4_SB(sb);
2757 	es = sbi->s_es;
2758 
2759 	if (es->s_error_count)
2760 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2761 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2762 			 le32_to_cpu(es->s_error_count));
2763 	if (es->s_first_error_time) {
2764 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2765 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2766 		       (int) sizeof(es->s_first_error_func),
2767 		       es->s_first_error_func,
2768 		       le32_to_cpu(es->s_first_error_line));
2769 		if (es->s_first_error_ino)
2770 			printk(KERN_CONT ": inode %u",
2771 			       le32_to_cpu(es->s_first_error_ino));
2772 		if (es->s_first_error_block)
2773 			printk(KERN_CONT ": block %llu", (unsigned long long)
2774 			       le64_to_cpu(es->s_first_error_block));
2775 		printk(KERN_CONT "\n");
2776 	}
2777 	if (es->s_last_error_time) {
2778 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2779 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2780 		       (int) sizeof(es->s_last_error_func),
2781 		       es->s_last_error_func,
2782 		       le32_to_cpu(es->s_last_error_line));
2783 		if (es->s_last_error_ino)
2784 			printk(KERN_CONT ": inode %u",
2785 			       le32_to_cpu(es->s_last_error_ino));
2786 		if (es->s_last_error_block)
2787 			printk(KERN_CONT ": block %llu", (unsigned long long)
2788 			       le64_to_cpu(es->s_last_error_block));
2789 		printk(KERN_CONT "\n");
2790 	}
2791 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2792 }
2793 
2794 /* Find next suitable group and run ext4_init_inode_table */
2795 static int ext4_run_li_request(struct ext4_li_request *elr)
2796 {
2797 	struct ext4_group_desc *gdp = NULL;
2798 	ext4_group_t group, ngroups;
2799 	struct super_block *sb;
2800 	unsigned long timeout = 0;
2801 	int ret = 0;
2802 
2803 	sb = elr->lr_super;
2804 	ngroups = EXT4_SB(sb)->s_groups_count;
2805 
2806 	for (group = elr->lr_next_group; group < ngroups; group++) {
2807 		gdp = ext4_get_group_desc(sb, group, NULL);
2808 		if (!gdp) {
2809 			ret = 1;
2810 			break;
2811 		}
2812 
2813 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2814 			break;
2815 	}
2816 
2817 	if (group >= ngroups)
2818 		ret = 1;
2819 
2820 	if (!ret) {
2821 		timeout = jiffies;
2822 		ret = ext4_init_inode_table(sb, group,
2823 					    elr->lr_timeout ? 0 : 1);
2824 		if (elr->lr_timeout == 0) {
2825 			timeout = (jiffies - timeout) *
2826 				  elr->lr_sbi->s_li_wait_mult;
2827 			elr->lr_timeout = timeout;
2828 		}
2829 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2830 		elr->lr_next_group = group + 1;
2831 	}
2832 	return ret;
2833 }
2834 
2835 /*
2836  * Remove lr_request from the list_request and free the
2837  * request structure. Should be called with li_list_mtx held
2838  */
2839 static void ext4_remove_li_request(struct ext4_li_request *elr)
2840 {
2841 	struct ext4_sb_info *sbi;
2842 
2843 	if (!elr)
2844 		return;
2845 
2846 	sbi = elr->lr_sbi;
2847 
2848 	list_del(&elr->lr_request);
2849 	sbi->s_li_request = NULL;
2850 	kfree(elr);
2851 }
2852 
2853 static void ext4_unregister_li_request(struct super_block *sb)
2854 {
2855 	mutex_lock(&ext4_li_mtx);
2856 	if (!ext4_li_info) {
2857 		mutex_unlock(&ext4_li_mtx);
2858 		return;
2859 	}
2860 
2861 	mutex_lock(&ext4_li_info->li_list_mtx);
2862 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2863 	mutex_unlock(&ext4_li_info->li_list_mtx);
2864 	mutex_unlock(&ext4_li_mtx);
2865 }
2866 
2867 static struct task_struct *ext4_lazyinit_task;
2868 
2869 /*
2870  * This is the function where ext4lazyinit thread lives. It walks
2871  * through the request list searching for next scheduled filesystem.
2872  * When such a fs is found, run the lazy initialization request
2873  * (ext4_rn_li_request) and keep track of the time spend in this
2874  * function. Based on that time we compute next schedule time of
2875  * the request. When walking through the list is complete, compute
2876  * next waking time and put itself into sleep.
2877  */
2878 static int ext4_lazyinit_thread(void *arg)
2879 {
2880 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2881 	struct list_head *pos, *n;
2882 	struct ext4_li_request *elr;
2883 	unsigned long next_wakeup, cur;
2884 
2885 	BUG_ON(NULL == eli);
2886 
2887 cont_thread:
2888 	while (true) {
2889 		next_wakeup = MAX_JIFFY_OFFSET;
2890 
2891 		mutex_lock(&eli->li_list_mtx);
2892 		if (list_empty(&eli->li_request_list)) {
2893 			mutex_unlock(&eli->li_list_mtx);
2894 			goto exit_thread;
2895 		}
2896 		list_for_each_safe(pos, n, &eli->li_request_list) {
2897 			int err = 0;
2898 			int progress = 0;
2899 			elr = list_entry(pos, struct ext4_li_request,
2900 					 lr_request);
2901 
2902 			if (time_before(jiffies, elr->lr_next_sched)) {
2903 				if (time_before(elr->lr_next_sched, next_wakeup))
2904 					next_wakeup = elr->lr_next_sched;
2905 				continue;
2906 			}
2907 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2908 				if (sb_start_write_trylock(elr->lr_super)) {
2909 					progress = 1;
2910 					/*
2911 					 * We hold sb->s_umount, sb can not
2912 					 * be removed from the list, it is
2913 					 * now safe to drop li_list_mtx
2914 					 */
2915 					mutex_unlock(&eli->li_list_mtx);
2916 					err = ext4_run_li_request(elr);
2917 					sb_end_write(elr->lr_super);
2918 					mutex_lock(&eli->li_list_mtx);
2919 					n = pos->next;
2920 				}
2921 				up_read((&elr->lr_super->s_umount));
2922 			}
2923 			/* error, remove the lazy_init job */
2924 			if (err) {
2925 				ext4_remove_li_request(elr);
2926 				continue;
2927 			}
2928 			if (!progress) {
2929 				elr->lr_next_sched = jiffies +
2930 					(prandom_u32()
2931 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2932 			}
2933 			if (time_before(elr->lr_next_sched, next_wakeup))
2934 				next_wakeup = elr->lr_next_sched;
2935 		}
2936 		mutex_unlock(&eli->li_list_mtx);
2937 
2938 		try_to_freeze();
2939 
2940 		cur = jiffies;
2941 		if ((time_after_eq(cur, next_wakeup)) ||
2942 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2943 			cond_resched();
2944 			continue;
2945 		}
2946 
2947 		schedule_timeout_interruptible(next_wakeup - cur);
2948 
2949 		if (kthread_should_stop()) {
2950 			ext4_clear_request_list();
2951 			goto exit_thread;
2952 		}
2953 	}
2954 
2955 exit_thread:
2956 	/*
2957 	 * It looks like the request list is empty, but we need
2958 	 * to check it under the li_list_mtx lock, to prevent any
2959 	 * additions into it, and of course we should lock ext4_li_mtx
2960 	 * to atomically free the list and ext4_li_info, because at
2961 	 * this point another ext4 filesystem could be registering
2962 	 * new one.
2963 	 */
2964 	mutex_lock(&ext4_li_mtx);
2965 	mutex_lock(&eli->li_list_mtx);
2966 	if (!list_empty(&eli->li_request_list)) {
2967 		mutex_unlock(&eli->li_list_mtx);
2968 		mutex_unlock(&ext4_li_mtx);
2969 		goto cont_thread;
2970 	}
2971 	mutex_unlock(&eli->li_list_mtx);
2972 	kfree(ext4_li_info);
2973 	ext4_li_info = NULL;
2974 	mutex_unlock(&ext4_li_mtx);
2975 
2976 	return 0;
2977 }
2978 
2979 static void ext4_clear_request_list(void)
2980 {
2981 	struct list_head *pos, *n;
2982 	struct ext4_li_request *elr;
2983 
2984 	mutex_lock(&ext4_li_info->li_list_mtx);
2985 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2986 		elr = list_entry(pos, struct ext4_li_request,
2987 				 lr_request);
2988 		ext4_remove_li_request(elr);
2989 	}
2990 	mutex_unlock(&ext4_li_info->li_list_mtx);
2991 }
2992 
2993 static int ext4_run_lazyinit_thread(void)
2994 {
2995 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2996 					 ext4_li_info, "ext4lazyinit");
2997 	if (IS_ERR(ext4_lazyinit_task)) {
2998 		int err = PTR_ERR(ext4_lazyinit_task);
2999 		ext4_clear_request_list();
3000 		kfree(ext4_li_info);
3001 		ext4_li_info = NULL;
3002 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3003 				 "initialization thread\n",
3004 				 err);
3005 		return err;
3006 	}
3007 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3008 	return 0;
3009 }
3010 
3011 /*
3012  * Check whether it make sense to run itable init. thread or not.
3013  * If there is at least one uninitialized inode table, return
3014  * corresponding group number, else the loop goes through all
3015  * groups and return total number of groups.
3016  */
3017 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3018 {
3019 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3020 	struct ext4_group_desc *gdp = NULL;
3021 
3022 	for (group = 0; group < ngroups; group++) {
3023 		gdp = ext4_get_group_desc(sb, group, NULL);
3024 		if (!gdp)
3025 			continue;
3026 
3027 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3028 			break;
3029 	}
3030 
3031 	return group;
3032 }
3033 
3034 static int ext4_li_info_new(void)
3035 {
3036 	struct ext4_lazy_init *eli = NULL;
3037 
3038 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3039 	if (!eli)
3040 		return -ENOMEM;
3041 
3042 	INIT_LIST_HEAD(&eli->li_request_list);
3043 	mutex_init(&eli->li_list_mtx);
3044 
3045 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3046 
3047 	ext4_li_info = eli;
3048 
3049 	return 0;
3050 }
3051 
3052 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3053 					    ext4_group_t start)
3054 {
3055 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3056 	struct ext4_li_request *elr;
3057 
3058 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3059 	if (!elr)
3060 		return NULL;
3061 
3062 	elr->lr_super = sb;
3063 	elr->lr_sbi = sbi;
3064 	elr->lr_next_group = start;
3065 
3066 	/*
3067 	 * Randomize first schedule time of the request to
3068 	 * spread the inode table initialization requests
3069 	 * better.
3070 	 */
3071 	elr->lr_next_sched = jiffies + (prandom_u32() %
3072 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3073 	return elr;
3074 }
3075 
3076 int ext4_register_li_request(struct super_block *sb,
3077 			     ext4_group_t first_not_zeroed)
3078 {
3079 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3080 	struct ext4_li_request *elr = NULL;
3081 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3082 	int ret = 0;
3083 
3084 	mutex_lock(&ext4_li_mtx);
3085 	if (sbi->s_li_request != NULL) {
3086 		/*
3087 		 * Reset timeout so it can be computed again, because
3088 		 * s_li_wait_mult might have changed.
3089 		 */
3090 		sbi->s_li_request->lr_timeout = 0;
3091 		goto out;
3092 	}
3093 
3094 	if (first_not_zeroed == ngroups ||
3095 	    (sb->s_flags & MS_RDONLY) ||
3096 	    !test_opt(sb, INIT_INODE_TABLE))
3097 		goto out;
3098 
3099 	elr = ext4_li_request_new(sb, first_not_zeroed);
3100 	if (!elr) {
3101 		ret = -ENOMEM;
3102 		goto out;
3103 	}
3104 
3105 	if (NULL == ext4_li_info) {
3106 		ret = ext4_li_info_new();
3107 		if (ret)
3108 			goto out;
3109 	}
3110 
3111 	mutex_lock(&ext4_li_info->li_list_mtx);
3112 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3113 	mutex_unlock(&ext4_li_info->li_list_mtx);
3114 
3115 	sbi->s_li_request = elr;
3116 	/*
3117 	 * set elr to NULL here since it has been inserted to
3118 	 * the request_list and the removal and free of it is
3119 	 * handled by ext4_clear_request_list from now on.
3120 	 */
3121 	elr = NULL;
3122 
3123 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3124 		ret = ext4_run_lazyinit_thread();
3125 		if (ret)
3126 			goto out;
3127 	}
3128 out:
3129 	mutex_unlock(&ext4_li_mtx);
3130 	if (ret)
3131 		kfree(elr);
3132 	return ret;
3133 }
3134 
3135 /*
3136  * We do not need to lock anything since this is called on
3137  * module unload.
3138  */
3139 static void ext4_destroy_lazyinit_thread(void)
3140 {
3141 	/*
3142 	 * If thread exited earlier
3143 	 * there's nothing to be done.
3144 	 */
3145 	if (!ext4_li_info || !ext4_lazyinit_task)
3146 		return;
3147 
3148 	kthread_stop(ext4_lazyinit_task);
3149 }
3150 
3151 static int set_journal_csum_feature_set(struct super_block *sb)
3152 {
3153 	int ret = 1;
3154 	int compat, incompat;
3155 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3156 
3157 	if (ext4_has_metadata_csum(sb)) {
3158 		/* journal checksum v3 */
3159 		compat = 0;
3160 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3161 	} else {
3162 		/* journal checksum v1 */
3163 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3164 		incompat = 0;
3165 	}
3166 
3167 	jbd2_journal_clear_features(sbi->s_journal,
3168 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3169 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3170 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3171 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3172 		ret = jbd2_journal_set_features(sbi->s_journal,
3173 				compat, 0,
3174 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3175 				incompat);
3176 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3177 		ret = jbd2_journal_set_features(sbi->s_journal,
3178 				compat, 0,
3179 				incompat);
3180 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3181 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3182 	} else {
3183 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3184 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3185 	}
3186 
3187 	return ret;
3188 }
3189 
3190 /*
3191  * Note: calculating the overhead so we can be compatible with
3192  * historical BSD practice is quite difficult in the face of
3193  * clusters/bigalloc.  This is because multiple metadata blocks from
3194  * different block group can end up in the same allocation cluster.
3195  * Calculating the exact overhead in the face of clustered allocation
3196  * requires either O(all block bitmaps) in memory or O(number of block
3197  * groups**2) in time.  We will still calculate the superblock for
3198  * older file systems --- and if we come across with a bigalloc file
3199  * system with zero in s_overhead_clusters the estimate will be close to
3200  * correct especially for very large cluster sizes --- but for newer
3201  * file systems, it's better to calculate this figure once at mkfs
3202  * time, and store it in the superblock.  If the superblock value is
3203  * present (even for non-bigalloc file systems), we will use it.
3204  */
3205 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3206 			  char *buf)
3207 {
3208 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3209 	struct ext4_group_desc	*gdp;
3210 	ext4_fsblk_t		first_block, last_block, b;
3211 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3212 	int			s, j, count = 0;
3213 
3214 	if (!ext4_has_feature_bigalloc(sb))
3215 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3216 			sbi->s_itb_per_group + 2);
3217 
3218 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3219 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3220 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3221 	for (i = 0; i < ngroups; i++) {
3222 		gdp = ext4_get_group_desc(sb, i, NULL);
3223 		b = ext4_block_bitmap(sb, gdp);
3224 		if (b >= first_block && b <= last_block) {
3225 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3226 			count++;
3227 		}
3228 		b = ext4_inode_bitmap(sb, gdp);
3229 		if (b >= first_block && b <= last_block) {
3230 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3231 			count++;
3232 		}
3233 		b = ext4_inode_table(sb, gdp);
3234 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3235 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3236 				int c = EXT4_B2C(sbi, b - first_block);
3237 				ext4_set_bit(c, buf);
3238 				count++;
3239 			}
3240 		if (i != grp)
3241 			continue;
3242 		s = 0;
3243 		if (ext4_bg_has_super(sb, grp)) {
3244 			ext4_set_bit(s++, buf);
3245 			count++;
3246 		}
3247 		j = ext4_bg_num_gdb(sb, grp);
3248 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3249 			ext4_error(sb, "Invalid number of block group "
3250 				   "descriptor blocks: %d", j);
3251 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3252 		}
3253 		count += j;
3254 		for (; j > 0; j--)
3255 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3256 	}
3257 	if (!count)
3258 		return 0;
3259 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3260 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3261 }
3262 
3263 /*
3264  * Compute the overhead and stash it in sbi->s_overhead
3265  */
3266 int ext4_calculate_overhead(struct super_block *sb)
3267 {
3268 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3269 	struct ext4_super_block *es = sbi->s_es;
3270 	struct inode *j_inode;
3271 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3272 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3273 	ext4_fsblk_t overhead = 0;
3274 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3275 
3276 	if (!buf)
3277 		return -ENOMEM;
3278 
3279 	/*
3280 	 * Compute the overhead (FS structures).  This is constant
3281 	 * for a given filesystem unless the number of block groups
3282 	 * changes so we cache the previous value until it does.
3283 	 */
3284 
3285 	/*
3286 	 * All of the blocks before first_data_block are overhead
3287 	 */
3288 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3289 
3290 	/*
3291 	 * Add the overhead found in each block group
3292 	 */
3293 	for (i = 0; i < ngroups; i++) {
3294 		int blks;
3295 
3296 		blks = count_overhead(sb, i, buf);
3297 		overhead += blks;
3298 		if (blks)
3299 			memset(buf, 0, PAGE_SIZE);
3300 		cond_resched();
3301 	}
3302 
3303 	/*
3304 	 * Add the internal journal blocks whether the journal has been
3305 	 * loaded or not
3306 	 */
3307 	if (sbi->s_journal && !sbi->journal_bdev)
3308 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3309 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3310 		j_inode = ext4_get_journal_inode(sb, j_inum);
3311 		if (j_inode) {
3312 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3313 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3314 			iput(j_inode);
3315 		} else {
3316 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3317 		}
3318 	}
3319 	sbi->s_overhead = overhead;
3320 	smp_wmb();
3321 	free_page((unsigned long) buf);
3322 	return 0;
3323 }
3324 
3325 static void ext4_set_resv_clusters(struct super_block *sb)
3326 {
3327 	ext4_fsblk_t resv_clusters;
3328 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3329 
3330 	/*
3331 	 * There's no need to reserve anything when we aren't using extents.
3332 	 * The space estimates are exact, there are no unwritten extents,
3333 	 * hole punching doesn't need new metadata... This is needed especially
3334 	 * to keep ext2/3 backward compatibility.
3335 	 */
3336 	if (!ext4_has_feature_extents(sb))
3337 		return;
3338 	/*
3339 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3340 	 * This should cover the situations where we can not afford to run
3341 	 * out of space like for example punch hole, or converting
3342 	 * unwritten extents in delalloc path. In most cases such
3343 	 * allocation would require 1, or 2 blocks, higher numbers are
3344 	 * very rare.
3345 	 */
3346 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3347 			 sbi->s_cluster_bits);
3348 
3349 	do_div(resv_clusters, 50);
3350 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3351 
3352 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3353 }
3354 
3355 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3356 {
3357 	char *orig_data = kstrdup(data, GFP_KERNEL);
3358 	struct buffer_head *bh;
3359 	struct ext4_super_block *es = NULL;
3360 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3361 	ext4_fsblk_t block;
3362 	ext4_fsblk_t sb_block = get_sb_block(&data);
3363 	ext4_fsblk_t logical_sb_block;
3364 	unsigned long offset = 0;
3365 	unsigned long journal_devnum = 0;
3366 	unsigned long def_mount_opts;
3367 	struct inode *root;
3368 	const char *descr;
3369 	int ret = -ENOMEM;
3370 	int blocksize, clustersize;
3371 	unsigned int db_count;
3372 	unsigned int i;
3373 	int needs_recovery, has_huge_files, has_bigalloc;
3374 	__u64 blocks_count;
3375 	int err = 0;
3376 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3377 	ext4_group_t first_not_zeroed;
3378 
3379 	if ((data && !orig_data) || !sbi)
3380 		goto out_free_base;
3381 
3382 	sbi->s_blockgroup_lock =
3383 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3384 	if (!sbi->s_blockgroup_lock)
3385 		goto out_free_base;
3386 
3387 	sb->s_fs_info = sbi;
3388 	sbi->s_sb = sb;
3389 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3390 	sbi->s_sb_block = sb_block;
3391 	if (sb->s_bdev->bd_part)
3392 		sbi->s_sectors_written_start =
3393 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3394 
3395 	/* Cleanup superblock name */
3396 	strreplace(sb->s_id, '/', '!');
3397 
3398 	/* -EINVAL is default */
3399 	ret = -EINVAL;
3400 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3401 	if (!blocksize) {
3402 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3403 		goto out_fail;
3404 	}
3405 
3406 	/*
3407 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3408 	 * block sizes.  We need to calculate the offset from buffer start.
3409 	 */
3410 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3411 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3412 		offset = do_div(logical_sb_block, blocksize);
3413 	} else {
3414 		logical_sb_block = sb_block;
3415 	}
3416 
3417 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3418 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3419 		goto out_fail;
3420 	}
3421 	/*
3422 	 * Note: s_es must be initialized as soon as possible because
3423 	 *       some ext4 macro-instructions depend on its value
3424 	 */
3425 	es = (struct ext4_super_block *) (bh->b_data + offset);
3426 	sbi->s_es = es;
3427 	sb->s_magic = le16_to_cpu(es->s_magic);
3428 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3429 		goto cantfind_ext4;
3430 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3431 
3432 	/* Warn if metadata_csum and gdt_csum are both set. */
3433 	if (ext4_has_feature_metadata_csum(sb) &&
3434 	    ext4_has_feature_gdt_csum(sb))
3435 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3436 			     "redundant flags; please run fsck.");
3437 
3438 	/* Check for a known checksum algorithm */
3439 	if (!ext4_verify_csum_type(sb, es)) {
3440 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3441 			 "unknown checksum algorithm.");
3442 		silent = 1;
3443 		goto cantfind_ext4;
3444 	}
3445 
3446 	/* Load the checksum driver */
3447 	if (ext4_has_feature_metadata_csum(sb)) {
3448 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3449 		if (IS_ERR(sbi->s_chksum_driver)) {
3450 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3451 			ret = PTR_ERR(sbi->s_chksum_driver);
3452 			sbi->s_chksum_driver = NULL;
3453 			goto failed_mount;
3454 		}
3455 	}
3456 
3457 	/* Check superblock checksum */
3458 	if (!ext4_superblock_csum_verify(sb, es)) {
3459 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3460 			 "invalid superblock checksum.  Run e2fsck?");
3461 		silent = 1;
3462 		ret = -EFSBADCRC;
3463 		goto cantfind_ext4;
3464 	}
3465 
3466 	/* Precompute checksum seed for all metadata */
3467 	if (ext4_has_feature_csum_seed(sb))
3468 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3469 	else if (ext4_has_metadata_csum(sb))
3470 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3471 					       sizeof(es->s_uuid));
3472 
3473 	/* Set defaults before we parse the mount options */
3474 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3475 	set_opt(sb, INIT_INODE_TABLE);
3476 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3477 		set_opt(sb, DEBUG);
3478 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3479 		set_opt(sb, GRPID);
3480 	if (def_mount_opts & EXT4_DEFM_UID16)
3481 		set_opt(sb, NO_UID32);
3482 	/* xattr user namespace & acls are now defaulted on */
3483 	set_opt(sb, XATTR_USER);
3484 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3485 	set_opt(sb, POSIX_ACL);
3486 #endif
3487 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3488 	if (ext4_has_metadata_csum(sb))
3489 		set_opt(sb, JOURNAL_CHECKSUM);
3490 
3491 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3492 		set_opt(sb, JOURNAL_DATA);
3493 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3494 		set_opt(sb, ORDERED_DATA);
3495 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3496 		set_opt(sb, WRITEBACK_DATA);
3497 
3498 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3499 		set_opt(sb, ERRORS_PANIC);
3500 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3501 		set_opt(sb, ERRORS_CONT);
3502 	else
3503 		set_opt(sb, ERRORS_RO);
3504 	/* block_validity enabled by default; disable with noblock_validity */
3505 	set_opt(sb, BLOCK_VALIDITY);
3506 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3507 		set_opt(sb, DISCARD);
3508 
3509 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3510 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3511 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3512 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3513 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3514 
3515 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3516 		set_opt(sb, BARRIER);
3517 
3518 	/*
3519 	 * enable delayed allocation by default
3520 	 * Use -o nodelalloc to turn it off
3521 	 */
3522 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3523 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3524 		set_opt(sb, DELALLOC);
3525 
3526 	/*
3527 	 * set default s_li_wait_mult for lazyinit, for the case there is
3528 	 * no mount option specified.
3529 	 */
3530 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3531 
3532 	if (sbi->s_es->s_mount_opts[0]) {
3533 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3534 					      sizeof(sbi->s_es->s_mount_opts),
3535 					      GFP_KERNEL);
3536 		if (!s_mount_opts)
3537 			goto failed_mount;
3538 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3539 				   &journal_ioprio, 0)) {
3540 			ext4_msg(sb, KERN_WARNING,
3541 				 "failed to parse options in superblock: %s",
3542 				 s_mount_opts);
3543 		}
3544 		kfree(s_mount_opts);
3545 	}
3546 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3547 	if (!parse_options((char *) data, sb, &journal_devnum,
3548 			   &journal_ioprio, 0))
3549 		goto failed_mount;
3550 
3551 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3552 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3553 			    "with data=journal disables delayed "
3554 			    "allocation and O_DIRECT support!\n");
3555 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3556 			ext4_msg(sb, KERN_ERR, "can't mount with "
3557 				 "both data=journal and delalloc");
3558 			goto failed_mount;
3559 		}
3560 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3561 			ext4_msg(sb, KERN_ERR, "can't mount with "
3562 				 "both data=journal and dioread_nolock");
3563 			goto failed_mount;
3564 		}
3565 		if (test_opt(sb, DAX)) {
3566 			ext4_msg(sb, KERN_ERR, "can't mount with "
3567 				 "both data=journal and dax");
3568 			goto failed_mount;
3569 		}
3570 		if (ext4_has_feature_encrypt(sb)) {
3571 			ext4_msg(sb, KERN_WARNING,
3572 				 "encrypted files will use data=ordered "
3573 				 "instead of data journaling mode");
3574 		}
3575 		if (test_opt(sb, DELALLOC))
3576 			clear_opt(sb, DELALLOC);
3577 	} else {
3578 		sb->s_iflags |= SB_I_CGROUPWB;
3579 	}
3580 
3581 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3582 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3583 
3584 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3585 	    (ext4_has_compat_features(sb) ||
3586 	     ext4_has_ro_compat_features(sb) ||
3587 	     ext4_has_incompat_features(sb)))
3588 		ext4_msg(sb, KERN_WARNING,
3589 		       "feature flags set on rev 0 fs, "
3590 		       "running e2fsck is recommended");
3591 
3592 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3593 		set_opt2(sb, HURD_COMPAT);
3594 		if (ext4_has_feature_64bit(sb)) {
3595 			ext4_msg(sb, KERN_ERR,
3596 				 "The Hurd can't support 64-bit file systems");
3597 			goto failed_mount;
3598 		}
3599 	}
3600 
3601 	if (IS_EXT2_SB(sb)) {
3602 		if (ext2_feature_set_ok(sb))
3603 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3604 				 "using the ext4 subsystem");
3605 		else {
3606 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3607 				 "to feature incompatibilities");
3608 			goto failed_mount;
3609 		}
3610 	}
3611 
3612 	if (IS_EXT3_SB(sb)) {
3613 		if (ext3_feature_set_ok(sb))
3614 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3615 				 "using the ext4 subsystem");
3616 		else {
3617 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3618 				 "to feature incompatibilities");
3619 			goto failed_mount;
3620 		}
3621 	}
3622 
3623 	/*
3624 	 * Check feature flags regardless of the revision level, since we
3625 	 * previously didn't change the revision level when setting the flags,
3626 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3627 	 */
3628 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3629 		goto failed_mount;
3630 
3631 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3632 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3633 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3634 		ext4_msg(sb, KERN_ERR,
3635 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3636 			 blocksize, le32_to_cpu(es->s_log_block_size));
3637 		goto failed_mount;
3638 	}
3639 	if (le32_to_cpu(es->s_log_block_size) >
3640 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3641 		ext4_msg(sb, KERN_ERR,
3642 			 "Invalid log block size: %u",
3643 			 le32_to_cpu(es->s_log_block_size));
3644 		goto failed_mount;
3645 	}
3646 
3647 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3648 		ext4_msg(sb, KERN_ERR,
3649 			 "Number of reserved GDT blocks insanely large: %d",
3650 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3651 		goto failed_mount;
3652 	}
3653 
3654 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3655 		err = bdev_dax_supported(sb, blocksize);
3656 		if (err)
3657 			goto failed_mount;
3658 	}
3659 
3660 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3661 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3662 			 es->s_encryption_level);
3663 		goto failed_mount;
3664 	}
3665 
3666 	if (sb->s_blocksize != blocksize) {
3667 		/* Validate the filesystem blocksize */
3668 		if (!sb_set_blocksize(sb, blocksize)) {
3669 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3670 					blocksize);
3671 			goto failed_mount;
3672 		}
3673 
3674 		brelse(bh);
3675 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3676 		offset = do_div(logical_sb_block, blocksize);
3677 		bh = sb_bread_unmovable(sb, logical_sb_block);
3678 		if (!bh) {
3679 			ext4_msg(sb, KERN_ERR,
3680 			       "Can't read superblock on 2nd try");
3681 			goto failed_mount;
3682 		}
3683 		es = (struct ext4_super_block *)(bh->b_data + offset);
3684 		sbi->s_es = es;
3685 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3686 			ext4_msg(sb, KERN_ERR,
3687 			       "Magic mismatch, very weird!");
3688 			goto failed_mount;
3689 		}
3690 	}
3691 
3692 	has_huge_files = ext4_has_feature_huge_file(sb);
3693 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3694 						      has_huge_files);
3695 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3696 
3697 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3698 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3699 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3700 	} else {
3701 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3702 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3703 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3704 		    (!is_power_of_2(sbi->s_inode_size)) ||
3705 		    (sbi->s_inode_size > blocksize)) {
3706 			ext4_msg(sb, KERN_ERR,
3707 			       "unsupported inode size: %d",
3708 			       sbi->s_inode_size);
3709 			goto failed_mount;
3710 		}
3711 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3712 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3713 	}
3714 
3715 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3716 	if (ext4_has_feature_64bit(sb)) {
3717 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3718 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3719 		    !is_power_of_2(sbi->s_desc_size)) {
3720 			ext4_msg(sb, KERN_ERR,
3721 			       "unsupported descriptor size %lu",
3722 			       sbi->s_desc_size);
3723 			goto failed_mount;
3724 		}
3725 	} else
3726 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3727 
3728 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3729 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3730 
3731 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3732 	if (sbi->s_inodes_per_block == 0)
3733 		goto cantfind_ext4;
3734 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3735 	    sbi->s_inodes_per_group > blocksize * 8) {
3736 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3737 			 sbi->s_blocks_per_group);
3738 		goto failed_mount;
3739 	}
3740 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3741 					sbi->s_inodes_per_block;
3742 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3743 	sbi->s_sbh = bh;
3744 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3745 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3746 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3747 
3748 	for (i = 0; i < 4; i++)
3749 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3750 	sbi->s_def_hash_version = es->s_def_hash_version;
3751 	if (ext4_has_feature_dir_index(sb)) {
3752 		i = le32_to_cpu(es->s_flags);
3753 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3754 			sbi->s_hash_unsigned = 3;
3755 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3756 #ifdef __CHAR_UNSIGNED__
3757 			if (!(sb->s_flags & MS_RDONLY))
3758 				es->s_flags |=
3759 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3760 			sbi->s_hash_unsigned = 3;
3761 #else
3762 			if (!(sb->s_flags & MS_RDONLY))
3763 				es->s_flags |=
3764 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3765 #endif
3766 		}
3767 	}
3768 
3769 	/* Handle clustersize */
3770 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3771 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3772 	if (has_bigalloc) {
3773 		if (clustersize < blocksize) {
3774 			ext4_msg(sb, KERN_ERR,
3775 				 "cluster size (%d) smaller than "
3776 				 "block size (%d)", clustersize, blocksize);
3777 			goto failed_mount;
3778 		}
3779 		if (le32_to_cpu(es->s_log_cluster_size) >
3780 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3781 			ext4_msg(sb, KERN_ERR,
3782 				 "Invalid log cluster size: %u",
3783 				 le32_to_cpu(es->s_log_cluster_size));
3784 			goto failed_mount;
3785 		}
3786 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3787 			le32_to_cpu(es->s_log_block_size);
3788 		sbi->s_clusters_per_group =
3789 			le32_to_cpu(es->s_clusters_per_group);
3790 		if (sbi->s_clusters_per_group > blocksize * 8) {
3791 			ext4_msg(sb, KERN_ERR,
3792 				 "#clusters per group too big: %lu",
3793 				 sbi->s_clusters_per_group);
3794 			goto failed_mount;
3795 		}
3796 		if (sbi->s_blocks_per_group !=
3797 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3798 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3799 				 "clusters per group (%lu) inconsistent",
3800 				 sbi->s_blocks_per_group,
3801 				 sbi->s_clusters_per_group);
3802 			goto failed_mount;
3803 		}
3804 	} else {
3805 		if (clustersize != blocksize) {
3806 			ext4_warning(sb, "fragment/cluster size (%d) != "
3807 				     "block size (%d)", clustersize,
3808 				     blocksize);
3809 			clustersize = blocksize;
3810 		}
3811 		if (sbi->s_blocks_per_group > blocksize * 8) {
3812 			ext4_msg(sb, KERN_ERR,
3813 				 "#blocks per group too big: %lu",
3814 				 sbi->s_blocks_per_group);
3815 			goto failed_mount;
3816 		}
3817 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3818 		sbi->s_cluster_bits = 0;
3819 	}
3820 	sbi->s_cluster_ratio = clustersize / blocksize;
3821 
3822 	/* Do we have standard group size of clustersize * 8 blocks ? */
3823 	if (sbi->s_blocks_per_group == clustersize << 3)
3824 		set_opt2(sb, STD_GROUP_SIZE);
3825 
3826 	/*
3827 	 * Test whether we have more sectors than will fit in sector_t,
3828 	 * and whether the max offset is addressable by the page cache.
3829 	 */
3830 	err = generic_check_addressable(sb->s_blocksize_bits,
3831 					ext4_blocks_count(es));
3832 	if (err) {
3833 		ext4_msg(sb, KERN_ERR, "filesystem"
3834 			 " too large to mount safely on this system");
3835 		if (sizeof(sector_t) < 8)
3836 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3837 		goto failed_mount;
3838 	}
3839 
3840 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3841 		goto cantfind_ext4;
3842 
3843 	/* check blocks count against device size */
3844 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3845 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3846 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3847 		       "exceeds size of device (%llu blocks)",
3848 		       ext4_blocks_count(es), blocks_count);
3849 		goto failed_mount;
3850 	}
3851 
3852 	/*
3853 	 * It makes no sense for the first data block to be beyond the end
3854 	 * of the filesystem.
3855 	 */
3856 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3857 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3858 			 "block %u is beyond end of filesystem (%llu)",
3859 			 le32_to_cpu(es->s_first_data_block),
3860 			 ext4_blocks_count(es));
3861 		goto failed_mount;
3862 	}
3863 	blocks_count = (ext4_blocks_count(es) -
3864 			le32_to_cpu(es->s_first_data_block) +
3865 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3866 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3867 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3868 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3869 		       "(block count %llu, first data block %u, "
3870 		       "blocks per group %lu)", sbi->s_groups_count,
3871 		       ext4_blocks_count(es),
3872 		       le32_to_cpu(es->s_first_data_block),
3873 		       EXT4_BLOCKS_PER_GROUP(sb));
3874 		goto failed_mount;
3875 	}
3876 	sbi->s_groups_count = blocks_count;
3877 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3878 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3879 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3880 		   EXT4_DESC_PER_BLOCK(sb);
3881 	if (ext4_has_feature_meta_bg(sb)) {
3882 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3883 			ext4_msg(sb, KERN_WARNING,
3884 				 "first meta block group too large: %u "
3885 				 "(group descriptor block count %u)",
3886 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3887 			goto failed_mount;
3888 		}
3889 	}
3890 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3891 					  sizeof(struct buffer_head *),
3892 					  GFP_KERNEL);
3893 	if (sbi->s_group_desc == NULL) {
3894 		ext4_msg(sb, KERN_ERR, "not enough memory");
3895 		ret = -ENOMEM;
3896 		goto failed_mount;
3897 	}
3898 
3899 	bgl_lock_init(sbi->s_blockgroup_lock);
3900 
3901 	for (i = 0; i < db_count; i++) {
3902 		block = descriptor_loc(sb, logical_sb_block, i);
3903 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3904 		if (!sbi->s_group_desc[i]) {
3905 			ext4_msg(sb, KERN_ERR,
3906 			       "can't read group descriptor %d", i);
3907 			db_count = i;
3908 			goto failed_mount2;
3909 		}
3910 	}
3911 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3912 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3913 		ret = -EFSCORRUPTED;
3914 		goto failed_mount2;
3915 	}
3916 
3917 	sbi->s_gdb_count = db_count;
3918 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3919 	spin_lock_init(&sbi->s_next_gen_lock);
3920 
3921 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3922 		(unsigned long) sb);
3923 
3924 	/* Register extent status tree shrinker */
3925 	if (ext4_es_register_shrinker(sbi))
3926 		goto failed_mount3;
3927 
3928 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3929 	sbi->s_extent_max_zeroout_kb = 32;
3930 
3931 	/*
3932 	 * set up enough so that it can read an inode
3933 	 */
3934 	sb->s_op = &ext4_sops;
3935 	sb->s_export_op = &ext4_export_ops;
3936 	sb->s_xattr = ext4_xattr_handlers;
3937 	sb->s_cop = &ext4_cryptops;
3938 #ifdef CONFIG_QUOTA
3939 	sb->dq_op = &ext4_quota_operations;
3940 	if (ext4_has_feature_quota(sb))
3941 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
3942 	else
3943 		sb->s_qcop = &ext4_qctl_operations;
3944 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3945 #endif
3946 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3947 
3948 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3949 	mutex_init(&sbi->s_orphan_lock);
3950 
3951 	sb->s_root = NULL;
3952 
3953 	needs_recovery = (es->s_last_orphan != 0 ||
3954 			  ext4_has_feature_journal_needs_recovery(sb));
3955 
3956 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3957 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3958 			goto failed_mount3a;
3959 
3960 	/*
3961 	 * The first inode we look at is the journal inode.  Don't try
3962 	 * root first: it may be modified in the journal!
3963 	 */
3964 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3965 		err = ext4_load_journal(sb, es, journal_devnum);
3966 		if (err)
3967 			goto failed_mount3a;
3968 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3969 		   ext4_has_feature_journal_needs_recovery(sb)) {
3970 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3971 		       "suppressed and not mounted read-only");
3972 		goto failed_mount_wq;
3973 	} else {
3974 		/* Nojournal mode, all journal mount options are illegal */
3975 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3976 			ext4_msg(sb, KERN_ERR, "can't mount with "
3977 				 "journal_checksum, fs mounted w/o journal");
3978 			goto failed_mount_wq;
3979 		}
3980 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3981 			ext4_msg(sb, KERN_ERR, "can't mount with "
3982 				 "journal_async_commit, fs mounted w/o journal");
3983 			goto failed_mount_wq;
3984 		}
3985 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3986 			ext4_msg(sb, KERN_ERR, "can't mount with "
3987 				 "commit=%lu, fs mounted w/o journal",
3988 				 sbi->s_commit_interval / HZ);
3989 			goto failed_mount_wq;
3990 		}
3991 		if (EXT4_MOUNT_DATA_FLAGS &
3992 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
3993 			ext4_msg(sb, KERN_ERR, "can't mount with "
3994 				 "data=, fs mounted w/o journal");
3995 			goto failed_mount_wq;
3996 		}
3997 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
3998 		clear_opt(sb, JOURNAL_CHECKSUM);
3999 		clear_opt(sb, DATA_FLAGS);
4000 		sbi->s_journal = NULL;
4001 		needs_recovery = 0;
4002 		goto no_journal;
4003 	}
4004 
4005 	if (ext4_has_feature_64bit(sb) &&
4006 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4007 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4008 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4009 		goto failed_mount_wq;
4010 	}
4011 
4012 	if (!set_journal_csum_feature_set(sb)) {
4013 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4014 			 "feature set");
4015 		goto failed_mount_wq;
4016 	}
4017 
4018 	/* We have now updated the journal if required, so we can
4019 	 * validate the data journaling mode. */
4020 	switch (test_opt(sb, DATA_FLAGS)) {
4021 	case 0:
4022 		/* No mode set, assume a default based on the journal
4023 		 * capabilities: ORDERED_DATA if the journal can
4024 		 * cope, else JOURNAL_DATA
4025 		 */
4026 		if (jbd2_journal_check_available_features
4027 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4028 			set_opt(sb, ORDERED_DATA);
4029 		else
4030 			set_opt(sb, JOURNAL_DATA);
4031 		break;
4032 
4033 	case EXT4_MOUNT_ORDERED_DATA:
4034 	case EXT4_MOUNT_WRITEBACK_DATA:
4035 		if (!jbd2_journal_check_available_features
4036 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4037 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4038 			       "requested data journaling mode");
4039 			goto failed_mount_wq;
4040 		}
4041 	default:
4042 		break;
4043 	}
4044 
4045 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4046 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4047 		ext4_msg(sb, KERN_ERR, "can't mount with "
4048 			"journal_async_commit in data=ordered mode");
4049 		goto failed_mount_wq;
4050 	}
4051 
4052 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4053 
4054 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4055 
4056 no_journal:
4057 	sbi->s_mb_cache = ext4_xattr_create_cache();
4058 	if (!sbi->s_mb_cache) {
4059 		ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4060 		goto failed_mount_wq;
4061 	}
4062 
4063 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4064 	    (blocksize != PAGE_SIZE)) {
4065 		ext4_msg(sb, KERN_ERR,
4066 			 "Unsupported blocksize for fs encryption");
4067 		goto failed_mount_wq;
4068 	}
4069 
4070 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4071 	    !ext4_has_feature_encrypt(sb)) {
4072 		ext4_set_feature_encrypt(sb);
4073 		ext4_commit_super(sb, 1);
4074 	}
4075 
4076 	/*
4077 	 * Get the # of file system overhead blocks from the
4078 	 * superblock if present.
4079 	 */
4080 	if (es->s_overhead_clusters)
4081 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4082 	else {
4083 		err = ext4_calculate_overhead(sb);
4084 		if (err)
4085 			goto failed_mount_wq;
4086 	}
4087 
4088 	/*
4089 	 * The maximum number of concurrent works can be high and
4090 	 * concurrency isn't really necessary.  Limit it to 1.
4091 	 */
4092 	EXT4_SB(sb)->rsv_conversion_wq =
4093 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4094 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4095 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4096 		ret = -ENOMEM;
4097 		goto failed_mount4;
4098 	}
4099 
4100 	/*
4101 	 * The jbd2_journal_load will have done any necessary log recovery,
4102 	 * so we can safely mount the rest of the filesystem now.
4103 	 */
4104 
4105 	root = ext4_iget(sb, EXT4_ROOT_INO);
4106 	if (IS_ERR(root)) {
4107 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4108 		ret = PTR_ERR(root);
4109 		root = NULL;
4110 		goto failed_mount4;
4111 	}
4112 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4113 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4114 		iput(root);
4115 		goto failed_mount4;
4116 	}
4117 	sb->s_root = d_make_root(root);
4118 	if (!sb->s_root) {
4119 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4120 		ret = -ENOMEM;
4121 		goto failed_mount4;
4122 	}
4123 
4124 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4125 		sb->s_flags |= MS_RDONLY;
4126 
4127 	/* determine the minimum size of new large inodes, if present */
4128 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4129 	    sbi->s_want_extra_isize == 0) {
4130 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4131 						     EXT4_GOOD_OLD_INODE_SIZE;
4132 		if (ext4_has_feature_extra_isize(sb)) {
4133 			if (sbi->s_want_extra_isize <
4134 			    le16_to_cpu(es->s_want_extra_isize))
4135 				sbi->s_want_extra_isize =
4136 					le16_to_cpu(es->s_want_extra_isize);
4137 			if (sbi->s_want_extra_isize <
4138 			    le16_to_cpu(es->s_min_extra_isize))
4139 				sbi->s_want_extra_isize =
4140 					le16_to_cpu(es->s_min_extra_isize);
4141 		}
4142 	}
4143 	/* Check if enough inode space is available */
4144 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4145 							sbi->s_inode_size) {
4146 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4147 						       EXT4_GOOD_OLD_INODE_SIZE;
4148 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4149 			 "available");
4150 	}
4151 
4152 	ext4_set_resv_clusters(sb);
4153 
4154 	err = ext4_setup_system_zone(sb);
4155 	if (err) {
4156 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4157 			 "zone (%d)", err);
4158 		goto failed_mount4a;
4159 	}
4160 
4161 	ext4_ext_init(sb);
4162 	err = ext4_mb_init(sb);
4163 	if (err) {
4164 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4165 			 err);
4166 		goto failed_mount5;
4167 	}
4168 
4169 	block = ext4_count_free_clusters(sb);
4170 	ext4_free_blocks_count_set(sbi->s_es,
4171 				   EXT4_C2B(sbi, block));
4172 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4173 				  GFP_KERNEL);
4174 	if (!err) {
4175 		unsigned long freei = ext4_count_free_inodes(sb);
4176 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4177 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4178 					  GFP_KERNEL);
4179 	}
4180 	if (!err)
4181 		err = percpu_counter_init(&sbi->s_dirs_counter,
4182 					  ext4_count_dirs(sb), GFP_KERNEL);
4183 	if (!err)
4184 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4185 					  GFP_KERNEL);
4186 	if (!err)
4187 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4188 
4189 	if (err) {
4190 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4191 		goto failed_mount6;
4192 	}
4193 
4194 	if (ext4_has_feature_flex_bg(sb))
4195 		if (!ext4_fill_flex_info(sb)) {
4196 			ext4_msg(sb, KERN_ERR,
4197 			       "unable to initialize "
4198 			       "flex_bg meta info!");
4199 			goto failed_mount6;
4200 		}
4201 
4202 	err = ext4_register_li_request(sb, first_not_zeroed);
4203 	if (err)
4204 		goto failed_mount6;
4205 
4206 	err = ext4_register_sysfs(sb);
4207 	if (err)
4208 		goto failed_mount7;
4209 
4210 #ifdef CONFIG_QUOTA
4211 	/* Enable quota usage during mount. */
4212 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4213 		err = ext4_enable_quotas(sb);
4214 		if (err)
4215 			goto failed_mount8;
4216 	}
4217 #endif  /* CONFIG_QUOTA */
4218 
4219 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4220 	ext4_orphan_cleanup(sb, es);
4221 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4222 	if (needs_recovery) {
4223 		ext4_msg(sb, KERN_INFO, "recovery complete");
4224 		ext4_mark_recovery_complete(sb, es);
4225 	}
4226 	if (EXT4_SB(sb)->s_journal) {
4227 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4228 			descr = " journalled data mode";
4229 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4230 			descr = " ordered data mode";
4231 		else
4232 			descr = " writeback data mode";
4233 	} else
4234 		descr = "out journal";
4235 
4236 	if (test_opt(sb, DISCARD)) {
4237 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4238 		if (!blk_queue_discard(q))
4239 			ext4_msg(sb, KERN_WARNING,
4240 				 "mounting with \"discard\" option, but "
4241 				 "the device does not support discard");
4242 	}
4243 
4244 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4245 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4246 			 "Opts: %.*s%s%s", descr,
4247 			 (int) sizeof(sbi->s_es->s_mount_opts),
4248 			 sbi->s_es->s_mount_opts,
4249 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4250 
4251 	if (es->s_error_count)
4252 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4253 
4254 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4255 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4256 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4257 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4258 
4259 	kfree(orig_data);
4260 	return 0;
4261 
4262 cantfind_ext4:
4263 	if (!silent)
4264 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4265 	goto failed_mount;
4266 
4267 #ifdef CONFIG_QUOTA
4268 failed_mount8:
4269 	ext4_unregister_sysfs(sb);
4270 #endif
4271 failed_mount7:
4272 	ext4_unregister_li_request(sb);
4273 failed_mount6:
4274 	ext4_mb_release(sb);
4275 	if (sbi->s_flex_groups)
4276 		kvfree(sbi->s_flex_groups);
4277 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4278 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4279 	percpu_counter_destroy(&sbi->s_dirs_counter);
4280 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4281 failed_mount5:
4282 	ext4_ext_release(sb);
4283 	ext4_release_system_zone(sb);
4284 failed_mount4a:
4285 	dput(sb->s_root);
4286 	sb->s_root = NULL;
4287 failed_mount4:
4288 	ext4_msg(sb, KERN_ERR, "mount failed");
4289 	if (EXT4_SB(sb)->rsv_conversion_wq)
4290 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4291 failed_mount_wq:
4292 	if (sbi->s_mb_cache) {
4293 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
4294 		sbi->s_mb_cache = NULL;
4295 	}
4296 	if (sbi->s_journal) {
4297 		jbd2_journal_destroy(sbi->s_journal);
4298 		sbi->s_journal = NULL;
4299 	}
4300 failed_mount3a:
4301 	ext4_es_unregister_shrinker(sbi);
4302 failed_mount3:
4303 	del_timer_sync(&sbi->s_err_report);
4304 	if (sbi->s_mmp_tsk)
4305 		kthread_stop(sbi->s_mmp_tsk);
4306 failed_mount2:
4307 	for (i = 0; i < db_count; i++)
4308 		brelse(sbi->s_group_desc[i]);
4309 	kvfree(sbi->s_group_desc);
4310 failed_mount:
4311 	if (sbi->s_chksum_driver)
4312 		crypto_free_shash(sbi->s_chksum_driver);
4313 #ifdef CONFIG_QUOTA
4314 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4315 		kfree(sbi->s_qf_names[i]);
4316 #endif
4317 	ext4_blkdev_remove(sbi);
4318 	brelse(bh);
4319 out_fail:
4320 	sb->s_fs_info = NULL;
4321 	kfree(sbi->s_blockgroup_lock);
4322 out_free_base:
4323 	kfree(sbi);
4324 	kfree(orig_data);
4325 	return err ? err : ret;
4326 }
4327 
4328 /*
4329  * Setup any per-fs journal parameters now.  We'll do this both on
4330  * initial mount, once the journal has been initialised but before we've
4331  * done any recovery; and again on any subsequent remount.
4332  */
4333 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4334 {
4335 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4336 
4337 	journal->j_commit_interval = sbi->s_commit_interval;
4338 	journal->j_min_batch_time = sbi->s_min_batch_time;
4339 	journal->j_max_batch_time = sbi->s_max_batch_time;
4340 
4341 	write_lock(&journal->j_state_lock);
4342 	if (test_opt(sb, BARRIER))
4343 		journal->j_flags |= JBD2_BARRIER;
4344 	else
4345 		journal->j_flags &= ~JBD2_BARRIER;
4346 	if (test_opt(sb, DATA_ERR_ABORT))
4347 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4348 	else
4349 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4350 	write_unlock(&journal->j_state_lock);
4351 }
4352 
4353 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4354 					     unsigned int journal_inum)
4355 {
4356 	struct inode *journal_inode;
4357 
4358 	/*
4359 	 * Test for the existence of a valid inode on disk.  Bad things
4360 	 * happen if we iget() an unused inode, as the subsequent iput()
4361 	 * will try to delete it.
4362 	 */
4363 	journal_inode = ext4_iget(sb, journal_inum);
4364 	if (IS_ERR(journal_inode)) {
4365 		ext4_msg(sb, KERN_ERR, "no journal found");
4366 		return NULL;
4367 	}
4368 	if (!journal_inode->i_nlink) {
4369 		make_bad_inode(journal_inode);
4370 		iput(journal_inode);
4371 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4372 		return NULL;
4373 	}
4374 
4375 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4376 		  journal_inode, journal_inode->i_size);
4377 	if (!S_ISREG(journal_inode->i_mode)) {
4378 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4379 		iput(journal_inode);
4380 		return NULL;
4381 	}
4382 	return journal_inode;
4383 }
4384 
4385 static journal_t *ext4_get_journal(struct super_block *sb,
4386 				   unsigned int journal_inum)
4387 {
4388 	struct inode *journal_inode;
4389 	journal_t *journal;
4390 
4391 	BUG_ON(!ext4_has_feature_journal(sb));
4392 
4393 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4394 	if (!journal_inode)
4395 		return NULL;
4396 
4397 	journal = jbd2_journal_init_inode(journal_inode);
4398 	if (!journal) {
4399 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4400 		iput(journal_inode);
4401 		return NULL;
4402 	}
4403 	journal->j_private = sb;
4404 	ext4_init_journal_params(sb, journal);
4405 	return journal;
4406 }
4407 
4408 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4409 				       dev_t j_dev)
4410 {
4411 	struct buffer_head *bh;
4412 	journal_t *journal;
4413 	ext4_fsblk_t start;
4414 	ext4_fsblk_t len;
4415 	int hblock, blocksize;
4416 	ext4_fsblk_t sb_block;
4417 	unsigned long offset;
4418 	struct ext4_super_block *es;
4419 	struct block_device *bdev;
4420 
4421 	BUG_ON(!ext4_has_feature_journal(sb));
4422 
4423 	bdev = ext4_blkdev_get(j_dev, sb);
4424 	if (bdev == NULL)
4425 		return NULL;
4426 
4427 	blocksize = sb->s_blocksize;
4428 	hblock = bdev_logical_block_size(bdev);
4429 	if (blocksize < hblock) {
4430 		ext4_msg(sb, KERN_ERR,
4431 			"blocksize too small for journal device");
4432 		goto out_bdev;
4433 	}
4434 
4435 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4436 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4437 	set_blocksize(bdev, blocksize);
4438 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4439 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4440 		       "external journal");
4441 		goto out_bdev;
4442 	}
4443 
4444 	es = (struct ext4_super_block *) (bh->b_data + offset);
4445 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4446 	    !(le32_to_cpu(es->s_feature_incompat) &
4447 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4448 		ext4_msg(sb, KERN_ERR, "external journal has "
4449 					"bad superblock");
4450 		brelse(bh);
4451 		goto out_bdev;
4452 	}
4453 
4454 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4455 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4456 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4457 		ext4_msg(sb, KERN_ERR, "external journal has "
4458 				       "corrupt superblock");
4459 		brelse(bh);
4460 		goto out_bdev;
4461 	}
4462 
4463 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4464 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4465 		brelse(bh);
4466 		goto out_bdev;
4467 	}
4468 
4469 	len = ext4_blocks_count(es);
4470 	start = sb_block + 1;
4471 	brelse(bh);	/* we're done with the superblock */
4472 
4473 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4474 					start, len, blocksize);
4475 	if (!journal) {
4476 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4477 		goto out_bdev;
4478 	}
4479 	journal->j_private = sb;
4480 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4481 	wait_on_buffer(journal->j_sb_buffer);
4482 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4483 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4484 		goto out_journal;
4485 	}
4486 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4487 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4488 					"user (unsupported) - %d",
4489 			be32_to_cpu(journal->j_superblock->s_nr_users));
4490 		goto out_journal;
4491 	}
4492 	EXT4_SB(sb)->journal_bdev = bdev;
4493 	ext4_init_journal_params(sb, journal);
4494 	return journal;
4495 
4496 out_journal:
4497 	jbd2_journal_destroy(journal);
4498 out_bdev:
4499 	ext4_blkdev_put(bdev);
4500 	return NULL;
4501 }
4502 
4503 static int ext4_load_journal(struct super_block *sb,
4504 			     struct ext4_super_block *es,
4505 			     unsigned long journal_devnum)
4506 {
4507 	journal_t *journal;
4508 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4509 	dev_t journal_dev;
4510 	int err = 0;
4511 	int really_read_only;
4512 
4513 	BUG_ON(!ext4_has_feature_journal(sb));
4514 
4515 	if (journal_devnum &&
4516 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4517 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4518 			"numbers have changed");
4519 		journal_dev = new_decode_dev(journal_devnum);
4520 	} else
4521 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4522 
4523 	really_read_only = bdev_read_only(sb->s_bdev);
4524 
4525 	/*
4526 	 * Are we loading a blank journal or performing recovery after a
4527 	 * crash?  For recovery, we need to check in advance whether we
4528 	 * can get read-write access to the device.
4529 	 */
4530 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4531 		if (sb->s_flags & MS_RDONLY) {
4532 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4533 					"required on readonly filesystem");
4534 			if (really_read_only) {
4535 				ext4_msg(sb, KERN_ERR, "write access "
4536 					"unavailable, cannot proceed");
4537 				return -EROFS;
4538 			}
4539 			ext4_msg(sb, KERN_INFO, "write access will "
4540 			       "be enabled during recovery");
4541 		}
4542 	}
4543 
4544 	if (journal_inum && journal_dev) {
4545 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4546 		       "and inode journals!");
4547 		return -EINVAL;
4548 	}
4549 
4550 	if (journal_inum) {
4551 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4552 			return -EINVAL;
4553 	} else {
4554 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4555 			return -EINVAL;
4556 	}
4557 
4558 	if (!(journal->j_flags & JBD2_BARRIER))
4559 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4560 
4561 	if (!ext4_has_feature_journal_needs_recovery(sb))
4562 		err = jbd2_journal_wipe(journal, !really_read_only);
4563 	if (!err) {
4564 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4565 		if (save)
4566 			memcpy(save, ((char *) es) +
4567 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4568 		err = jbd2_journal_load(journal);
4569 		if (save)
4570 			memcpy(((char *) es) + EXT4_S_ERR_START,
4571 			       save, EXT4_S_ERR_LEN);
4572 		kfree(save);
4573 	}
4574 
4575 	if (err) {
4576 		ext4_msg(sb, KERN_ERR, "error loading journal");
4577 		jbd2_journal_destroy(journal);
4578 		return err;
4579 	}
4580 
4581 	EXT4_SB(sb)->s_journal = journal;
4582 	ext4_clear_journal_err(sb, es);
4583 
4584 	if (!really_read_only && journal_devnum &&
4585 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4586 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4587 
4588 		/* Make sure we flush the recovery flag to disk. */
4589 		ext4_commit_super(sb, 1);
4590 	}
4591 
4592 	return 0;
4593 }
4594 
4595 static int ext4_commit_super(struct super_block *sb, int sync)
4596 {
4597 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4598 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4599 	int error = 0;
4600 
4601 	if (!sbh || block_device_ejected(sb))
4602 		return error;
4603 	/*
4604 	 * If the file system is mounted read-only, don't update the
4605 	 * superblock write time.  This avoids updating the superblock
4606 	 * write time when we are mounting the root file system
4607 	 * read/only but we need to replay the journal; at that point,
4608 	 * for people who are east of GMT and who make their clock
4609 	 * tick in localtime for Windows bug-for-bug compatibility,
4610 	 * the clock is set in the future, and this will cause e2fsck
4611 	 * to complain and force a full file system check.
4612 	 */
4613 	if (!(sb->s_flags & MS_RDONLY))
4614 		es->s_wtime = cpu_to_le32(get_seconds());
4615 	if (sb->s_bdev->bd_part)
4616 		es->s_kbytes_written =
4617 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4618 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4619 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4620 	else
4621 		es->s_kbytes_written =
4622 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4623 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4624 		ext4_free_blocks_count_set(es,
4625 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4626 				&EXT4_SB(sb)->s_freeclusters_counter)));
4627 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4628 		es->s_free_inodes_count =
4629 			cpu_to_le32(percpu_counter_sum_positive(
4630 				&EXT4_SB(sb)->s_freeinodes_counter));
4631 	BUFFER_TRACE(sbh, "marking dirty");
4632 	ext4_superblock_csum_set(sb);
4633 	if (sync)
4634 		lock_buffer(sbh);
4635 	if (buffer_write_io_error(sbh)) {
4636 		/*
4637 		 * Oh, dear.  A previous attempt to write the
4638 		 * superblock failed.  This could happen because the
4639 		 * USB device was yanked out.  Or it could happen to
4640 		 * be a transient write error and maybe the block will
4641 		 * be remapped.  Nothing we can do but to retry the
4642 		 * write and hope for the best.
4643 		 */
4644 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4645 		       "superblock detected");
4646 		clear_buffer_write_io_error(sbh);
4647 		set_buffer_uptodate(sbh);
4648 	}
4649 	mark_buffer_dirty(sbh);
4650 	if (sync) {
4651 		unlock_buffer(sbh);
4652 		error = __sync_dirty_buffer(sbh,
4653 			test_opt(sb, BARRIER) ? REQ_FUA : REQ_SYNC);
4654 		if (error)
4655 			return error;
4656 
4657 		error = buffer_write_io_error(sbh);
4658 		if (error) {
4659 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4660 			       "superblock");
4661 			clear_buffer_write_io_error(sbh);
4662 			set_buffer_uptodate(sbh);
4663 		}
4664 	}
4665 	return error;
4666 }
4667 
4668 /*
4669  * Have we just finished recovery?  If so, and if we are mounting (or
4670  * remounting) the filesystem readonly, then we will end up with a
4671  * consistent fs on disk.  Record that fact.
4672  */
4673 static void ext4_mark_recovery_complete(struct super_block *sb,
4674 					struct ext4_super_block *es)
4675 {
4676 	journal_t *journal = EXT4_SB(sb)->s_journal;
4677 
4678 	if (!ext4_has_feature_journal(sb)) {
4679 		BUG_ON(journal != NULL);
4680 		return;
4681 	}
4682 	jbd2_journal_lock_updates(journal);
4683 	if (jbd2_journal_flush(journal) < 0)
4684 		goto out;
4685 
4686 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4687 	    sb->s_flags & MS_RDONLY) {
4688 		ext4_clear_feature_journal_needs_recovery(sb);
4689 		ext4_commit_super(sb, 1);
4690 	}
4691 
4692 out:
4693 	jbd2_journal_unlock_updates(journal);
4694 }
4695 
4696 /*
4697  * If we are mounting (or read-write remounting) a filesystem whose journal
4698  * has recorded an error from a previous lifetime, move that error to the
4699  * main filesystem now.
4700  */
4701 static void ext4_clear_journal_err(struct super_block *sb,
4702 				   struct ext4_super_block *es)
4703 {
4704 	journal_t *journal;
4705 	int j_errno;
4706 	const char *errstr;
4707 
4708 	BUG_ON(!ext4_has_feature_journal(sb));
4709 
4710 	journal = EXT4_SB(sb)->s_journal;
4711 
4712 	/*
4713 	 * Now check for any error status which may have been recorded in the
4714 	 * journal by a prior ext4_error() or ext4_abort()
4715 	 */
4716 
4717 	j_errno = jbd2_journal_errno(journal);
4718 	if (j_errno) {
4719 		char nbuf[16];
4720 
4721 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4722 		ext4_warning(sb, "Filesystem error recorded "
4723 			     "from previous mount: %s", errstr);
4724 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4725 
4726 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4727 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4728 		ext4_commit_super(sb, 1);
4729 
4730 		jbd2_journal_clear_err(journal);
4731 		jbd2_journal_update_sb_errno(journal);
4732 	}
4733 }
4734 
4735 /*
4736  * Force the running and committing transactions to commit,
4737  * and wait on the commit.
4738  */
4739 int ext4_force_commit(struct super_block *sb)
4740 {
4741 	journal_t *journal;
4742 
4743 	if (sb->s_flags & MS_RDONLY)
4744 		return 0;
4745 
4746 	journal = EXT4_SB(sb)->s_journal;
4747 	return ext4_journal_force_commit(journal);
4748 }
4749 
4750 static int ext4_sync_fs(struct super_block *sb, int wait)
4751 {
4752 	int ret = 0;
4753 	tid_t target;
4754 	bool needs_barrier = false;
4755 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4756 
4757 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4758 		return 0;
4759 
4760 	trace_ext4_sync_fs(sb, wait);
4761 	flush_workqueue(sbi->rsv_conversion_wq);
4762 	/*
4763 	 * Writeback quota in non-journalled quota case - journalled quota has
4764 	 * no dirty dquots
4765 	 */
4766 	dquot_writeback_dquots(sb, -1);
4767 	/*
4768 	 * Data writeback is possible w/o journal transaction, so barrier must
4769 	 * being sent at the end of the function. But we can skip it if
4770 	 * transaction_commit will do it for us.
4771 	 */
4772 	if (sbi->s_journal) {
4773 		target = jbd2_get_latest_transaction(sbi->s_journal);
4774 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4775 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4776 			needs_barrier = true;
4777 
4778 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4779 			if (wait)
4780 				ret = jbd2_log_wait_commit(sbi->s_journal,
4781 							   target);
4782 		}
4783 	} else if (wait && test_opt(sb, BARRIER))
4784 		needs_barrier = true;
4785 	if (needs_barrier) {
4786 		int err;
4787 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4788 		if (!ret)
4789 			ret = err;
4790 	}
4791 
4792 	return ret;
4793 }
4794 
4795 /*
4796  * LVM calls this function before a (read-only) snapshot is created.  This
4797  * gives us a chance to flush the journal completely and mark the fs clean.
4798  *
4799  * Note that only this function cannot bring a filesystem to be in a clean
4800  * state independently. It relies on upper layer to stop all data & metadata
4801  * modifications.
4802  */
4803 static int ext4_freeze(struct super_block *sb)
4804 {
4805 	int error = 0;
4806 	journal_t *journal;
4807 
4808 	if (sb->s_flags & MS_RDONLY)
4809 		return 0;
4810 
4811 	journal = EXT4_SB(sb)->s_journal;
4812 
4813 	if (journal) {
4814 		/* Now we set up the journal barrier. */
4815 		jbd2_journal_lock_updates(journal);
4816 
4817 		/*
4818 		 * Don't clear the needs_recovery flag if we failed to
4819 		 * flush the journal.
4820 		 */
4821 		error = jbd2_journal_flush(journal);
4822 		if (error < 0)
4823 			goto out;
4824 
4825 		/* Journal blocked and flushed, clear needs_recovery flag. */
4826 		ext4_clear_feature_journal_needs_recovery(sb);
4827 	}
4828 
4829 	error = ext4_commit_super(sb, 1);
4830 out:
4831 	if (journal)
4832 		/* we rely on upper layer to stop further updates */
4833 		jbd2_journal_unlock_updates(journal);
4834 	return error;
4835 }
4836 
4837 /*
4838  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4839  * flag here, even though the filesystem is not technically dirty yet.
4840  */
4841 static int ext4_unfreeze(struct super_block *sb)
4842 {
4843 	if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4844 		return 0;
4845 
4846 	if (EXT4_SB(sb)->s_journal) {
4847 		/* Reset the needs_recovery flag before the fs is unlocked. */
4848 		ext4_set_feature_journal_needs_recovery(sb);
4849 	}
4850 
4851 	ext4_commit_super(sb, 1);
4852 	return 0;
4853 }
4854 
4855 /*
4856  * Structure to save mount options for ext4_remount's benefit
4857  */
4858 struct ext4_mount_options {
4859 	unsigned long s_mount_opt;
4860 	unsigned long s_mount_opt2;
4861 	kuid_t s_resuid;
4862 	kgid_t s_resgid;
4863 	unsigned long s_commit_interval;
4864 	u32 s_min_batch_time, s_max_batch_time;
4865 #ifdef CONFIG_QUOTA
4866 	int s_jquota_fmt;
4867 	char *s_qf_names[EXT4_MAXQUOTAS];
4868 #endif
4869 };
4870 
4871 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4872 {
4873 	struct ext4_super_block *es;
4874 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4875 	unsigned long old_sb_flags;
4876 	struct ext4_mount_options old_opts;
4877 	int enable_quota = 0;
4878 	ext4_group_t g;
4879 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4880 	int err = 0;
4881 #ifdef CONFIG_QUOTA
4882 	int i, j;
4883 #endif
4884 	char *orig_data = kstrdup(data, GFP_KERNEL);
4885 
4886 	/* Store the original options */
4887 	old_sb_flags = sb->s_flags;
4888 	old_opts.s_mount_opt = sbi->s_mount_opt;
4889 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4890 	old_opts.s_resuid = sbi->s_resuid;
4891 	old_opts.s_resgid = sbi->s_resgid;
4892 	old_opts.s_commit_interval = sbi->s_commit_interval;
4893 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4894 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4895 #ifdef CONFIG_QUOTA
4896 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4897 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4898 		if (sbi->s_qf_names[i]) {
4899 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4900 							 GFP_KERNEL);
4901 			if (!old_opts.s_qf_names[i]) {
4902 				for (j = 0; j < i; j++)
4903 					kfree(old_opts.s_qf_names[j]);
4904 				kfree(orig_data);
4905 				return -ENOMEM;
4906 			}
4907 		} else
4908 			old_opts.s_qf_names[i] = NULL;
4909 #endif
4910 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4911 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4912 
4913 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4914 		err = -EINVAL;
4915 		goto restore_opts;
4916 	}
4917 
4918 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4919 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4920 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4921 			 "during remount not supported; ignoring");
4922 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4923 	}
4924 
4925 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4926 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4927 			ext4_msg(sb, KERN_ERR, "can't mount with "
4928 				 "both data=journal and delalloc");
4929 			err = -EINVAL;
4930 			goto restore_opts;
4931 		}
4932 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4933 			ext4_msg(sb, KERN_ERR, "can't mount with "
4934 				 "both data=journal and dioread_nolock");
4935 			err = -EINVAL;
4936 			goto restore_opts;
4937 		}
4938 		if (test_opt(sb, DAX)) {
4939 			ext4_msg(sb, KERN_ERR, "can't mount with "
4940 				 "both data=journal and dax");
4941 			err = -EINVAL;
4942 			goto restore_opts;
4943 		}
4944 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
4945 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4946 			ext4_msg(sb, KERN_ERR, "can't mount with "
4947 				"journal_async_commit in data=ordered mode");
4948 			err = -EINVAL;
4949 			goto restore_opts;
4950 		}
4951 	}
4952 
4953 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4954 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4955 			"dax flag with busy inodes while remounting");
4956 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4957 	}
4958 
4959 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4960 		ext4_abort(sb, "Abort forced by user");
4961 
4962 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4963 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4964 
4965 	es = sbi->s_es;
4966 
4967 	if (sbi->s_journal) {
4968 		ext4_init_journal_params(sb, sbi->s_journal);
4969 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4970 	}
4971 
4972 	if (*flags & MS_LAZYTIME)
4973 		sb->s_flags |= MS_LAZYTIME;
4974 
4975 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4976 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4977 			err = -EROFS;
4978 			goto restore_opts;
4979 		}
4980 
4981 		if (*flags & MS_RDONLY) {
4982 			err = sync_filesystem(sb);
4983 			if (err < 0)
4984 				goto restore_opts;
4985 			err = dquot_suspend(sb, -1);
4986 			if (err < 0)
4987 				goto restore_opts;
4988 
4989 			/*
4990 			 * First of all, the unconditional stuff we have to do
4991 			 * to disable replay of the journal when we next remount
4992 			 */
4993 			sb->s_flags |= MS_RDONLY;
4994 
4995 			/*
4996 			 * OK, test if we are remounting a valid rw partition
4997 			 * readonly, and if so set the rdonly flag and then
4998 			 * mark the partition as valid again.
4999 			 */
5000 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5001 			    (sbi->s_mount_state & EXT4_VALID_FS))
5002 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5003 
5004 			if (sbi->s_journal)
5005 				ext4_mark_recovery_complete(sb, es);
5006 		} else {
5007 			/* Make sure we can mount this feature set readwrite */
5008 			if (ext4_has_feature_readonly(sb) ||
5009 			    !ext4_feature_set_ok(sb, 0)) {
5010 				err = -EROFS;
5011 				goto restore_opts;
5012 			}
5013 			/*
5014 			 * Make sure the group descriptor checksums
5015 			 * are sane.  If they aren't, refuse to remount r/w.
5016 			 */
5017 			for (g = 0; g < sbi->s_groups_count; g++) {
5018 				struct ext4_group_desc *gdp =
5019 					ext4_get_group_desc(sb, g, NULL);
5020 
5021 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5022 					ext4_msg(sb, KERN_ERR,
5023 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5024 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5025 					       le16_to_cpu(gdp->bg_checksum));
5026 					err = -EFSBADCRC;
5027 					goto restore_opts;
5028 				}
5029 			}
5030 
5031 			/*
5032 			 * If we have an unprocessed orphan list hanging
5033 			 * around from a previously readonly bdev mount,
5034 			 * require a full umount/remount for now.
5035 			 */
5036 			if (es->s_last_orphan) {
5037 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5038 				       "remount RDWR because of unprocessed "
5039 				       "orphan inode list.  Please "
5040 				       "umount/remount instead");
5041 				err = -EINVAL;
5042 				goto restore_opts;
5043 			}
5044 
5045 			/*
5046 			 * Mounting a RDONLY partition read-write, so reread
5047 			 * and store the current valid flag.  (It may have
5048 			 * been changed by e2fsck since we originally mounted
5049 			 * the partition.)
5050 			 */
5051 			if (sbi->s_journal)
5052 				ext4_clear_journal_err(sb, es);
5053 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5054 			if (!ext4_setup_super(sb, es, 0))
5055 				sb->s_flags &= ~MS_RDONLY;
5056 			if (ext4_has_feature_mmp(sb))
5057 				if (ext4_multi_mount_protect(sb,
5058 						le64_to_cpu(es->s_mmp_block))) {
5059 					err = -EROFS;
5060 					goto restore_opts;
5061 				}
5062 			enable_quota = 1;
5063 		}
5064 	}
5065 
5066 	/*
5067 	 * Reinitialize lazy itable initialization thread based on
5068 	 * current settings
5069 	 */
5070 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5071 		ext4_unregister_li_request(sb);
5072 	else {
5073 		ext4_group_t first_not_zeroed;
5074 		first_not_zeroed = ext4_has_uninit_itable(sb);
5075 		ext4_register_li_request(sb, first_not_zeroed);
5076 	}
5077 
5078 	ext4_setup_system_zone(sb);
5079 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5080 		ext4_commit_super(sb, 1);
5081 
5082 #ifdef CONFIG_QUOTA
5083 	/* Release old quota file names */
5084 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5085 		kfree(old_opts.s_qf_names[i]);
5086 	if (enable_quota) {
5087 		if (sb_any_quota_suspended(sb))
5088 			dquot_resume(sb, -1);
5089 		else if (ext4_has_feature_quota(sb)) {
5090 			err = ext4_enable_quotas(sb);
5091 			if (err)
5092 				goto restore_opts;
5093 		}
5094 	}
5095 #endif
5096 
5097 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5098 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5099 	kfree(orig_data);
5100 	return 0;
5101 
5102 restore_opts:
5103 	sb->s_flags = old_sb_flags;
5104 	sbi->s_mount_opt = old_opts.s_mount_opt;
5105 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5106 	sbi->s_resuid = old_opts.s_resuid;
5107 	sbi->s_resgid = old_opts.s_resgid;
5108 	sbi->s_commit_interval = old_opts.s_commit_interval;
5109 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5110 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5111 #ifdef CONFIG_QUOTA
5112 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5113 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5114 		kfree(sbi->s_qf_names[i]);
5115 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5116 	}
5117 #endif
5118 	kfree(orig_data);
5119 	return err;
5120 }
5121 
5122 #ifdef CONFIG_QUOTA
5123 static int ext4_statfs_project(struct super_block *sb,
5124 			       kprojid_t projid, struct kstatfs *buf)
5125 {
5126 	struct kqid qid;
5127 	struct dquot *dquot;
5128 	u64 limit;
5129 	u64 curblock;
5130 
5131 	qid = make_kqid_projid(projid);
5132 	dquot = dqget(sb, qid);
5133 	if (IS_ERR(dquot))
5134 		return PTR_ERR(dquot);
5135 	spin_lock(&dq_data_lock);
5136 
5137 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5138 		 dquot->dq_dqb.dqb_bsoftlimit :
5139 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5140 	if (limit && buf->f_blocks > limit) {
5141 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5142 		buf->f_blocks = limit;
5143 		buf->f_bfree = buf->f_bavail =
5144 			(buf->f_blocks > curblock) ?
5145 			 (buf->f_blocks - curblock) : 0;
5146 	}
5147 
5148 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5149 		dquot->dq_dqb.dqb_isoftlimit :
5150 		dquot->dq_dqb.dqb_ihardlimit;
5151 	if (limit && buf->f_files > limit) {
5152 		buf->f_files = limit;
5153 		buf->f_ffree =
5154 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5155 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5156 	}
5157 
5158 	spin_unlock(&dq_data_lock);
5159 	dqput(dquot);
5160 	return 0;
5161 }
5162 #endif
5163 
5164 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5165 {
5166 	struct super_block *sb = dentry->d_sb;
5167 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5168 	struct ext4_super_block *es = sbi->s_es;
5169 	ext4_fsblk_t overhead = 0, resv_blocks;
5170 	u64 fsid;
5171 	s64 bfree;
5172 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5173 
5174 	if (!test_opt(sb, MINIX_DF))
5175 		overhead = sbi->s_overhead;
5176 
5177 	buf->f_type = EXT4_SUPER_MAGIC;
5178 	buf->f_bsize = sb->s_blocksize;
5179 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5180 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5181 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5182 	/* prevent underflow in case that few free space is available */
5183 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5184 	buf->f_bavail = buf->f_bfree -
5185 			(ext4_r_blocks_count(es) + resv_blocks);
5186 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5187 		buf->f_bavail = 0;
5188 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5189 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5190 	buf->f_namelen = EXT4_NAME_LEN;
5191 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5192 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5193 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5194 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5195 
5196 #ifdef CONFIG_QUOTA
5197 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5198 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5199 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5200 #endif
5201 	return 0;
5202 }
5203 
5204 /* Helper function for writing quotas on sync - we need to start transaction
5205  * before quota file is locked for write. Otherwise the are possible deadlocks:
5206  * Process 1                         Process 2
5207  * ext4_create()                     quota_sync()
5208  *   jbd2_journal_start()                  write_dquot()
5209  *   dquot_initialize()                         down(dqio_mutex)
5210  *     down(dqio_mutex)                    jbd2_journal_start()
5211  *
5212  */
5213 
5214 #ifdef CONFIG_QUOTA
5215 
5216 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5217 {
5218 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5219 }
5220 
5221 static int ext4_write_dquot(struct dquot *dquot)
5222 {
5223 	int ret, err;
5224 	handle_t *handle;
5225 	struct inode *inode;
5226 
5227 	inode = dquot_to_inode(dquot);
5228 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5229 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5230 	if (IS_ERR(handle))
5231 		return PTR_ERR(handle);
5232 	ret = dquot_commit(dquot);
5233 	err = ext4_journal_stop(handle);
5234 	if (!ret)
5235 		ret = err;
5236 	return ret;
5237 }
5238 
5239 static int ext4_acquire_dquot(struct dquot *dquot)
5240 {
5241 	int ret, err;
5242 	handle_t *handle;
5243 
5244 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5245 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5246 	if (IS_ERR(handle))
5247 		return PTR_ERR(handle);
5248 	ret = dquot_acquire(dquot);
5249 	err = ext4_journal_stop(handle);
5250 	if (!ret)
5251 		ret = err;
5252 	return ret;
5253 }
5254 
5255 static int ext4_release_dquot(struct dquot *dquot)
5256 {
5257 	int ret, err;
5258 	handle_t *handle;
5259 
5260 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5261 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5262 	if (IS_ERR(handle)) {
5263 		/* Release dquot anyway to avoid endless cycle in dqput() */
5264 		dquot_release(dquot);
5265 		return PTR_ERR(handle);
5266 	}
5267 	ret = dquot_release(dquot);
5268 	err = ext4_journal_stop(handle);
5269 	if (!ret)
5270 		ret = err;
5271 	return ret;
5272 }
5273 
5274 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5275 {
5276 	struct super_block *sb = dquot->dq_sb;
5277 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5278 
5279 	/* Are we journaling quotas? */
5280 	if (ext4_has_feature_quota(sb) ||
5281 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5282 		dquot_mark_dquot_dirty(dquot);
5283 		return ext4_write_dquot(dquot);
5284 	} else {
5285 		return dquot_mark_dquot_dirty(dquot);
5286 	}
5287 }
5288 
5289 static int ext4_write_info(struct super_block *sb, int type)
5290 {
5291 	int ret, err;
5292 	handle_t *handle;
5293 
5294 	/* Data block + inode block */
5295 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5296 	if (IS_ERR(handle))
5297 		return PTR_ERR(handle);
5298 	ret = dquot_commit_info(sb, type);
5299 	err = ext4_journal_stop(handle);
5300 	if (!ret)
5301 		ret = err;
5302 	return ret;
5303 }
5304 
5305 /*
5306  * Turn on quotas during mount time - we need to find
5307  * the quota file and such...
5308  */
5309 static int ext4_quota_on_mount(struct super_block *sb, int type)
5310 {
5311 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5312 					EXT4_SB(sb)->s_jquota_fmt, type);
5313 }
5314 
5315 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5316 {
5317 	struct ext4_inode_info *ei = EXT4_I(inode);
5318 
5319 	/* The first argument of lockdep_set_subclass has to be
5320 	 * *exactly* the same as the argument to init_rwsem() --- in
5321 	 * this case, in init_once() --- or lockdep gets unhappy
5322 	 * because the name of the lock is set using the
5323 	 * stringification of the argument to init_rwsem().
5324 	 */
5325 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5326 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5327 }
5328 
5329 /*
5330  * Standard function to be called on quota_on
5331  */
5332 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5333 			 const struct path *path)
5334 {
5335 	int err;
5336 
5337 	if (!test_opt(sb, QUOTA))
5338 		return -EINVAL;
5339 
5340 	/* Quotafile not on the same filesystem? */
5341 	if (path->dentry->d_sb != sb)
5342 		return -EXDEV;
5343 	/* Journaling quota? */
5344 	if (EXT4_SB(sb)->s_qf_names[type]) {
5345 		/* Quotafile not in fs root? */
5346 		if (path->dentry->d_parent != sb->s_root)
5347 			ext4_msg(sb, KERN_WARNING,
5348 				"Quota file not on filesystem root. "
5349 				"Journaled quota will not work");
5350 	}
5351 
5352 	/*
5353 	 * When we journal data on quota file, we have to flush journal to see
5354 	 * all updates to the file when we bypass pagecache...
5355 	 */
5356 	if (EXT4_SB(sb)->s_journal &&
5357 	    ext4_should_journal_data(d_inode(path->dentry))) {
5358 		/*
5359 		 * We don't need to lock updates but journal_flush() could
5360 		 * otherwise be livelocked...
5361 		 */
5362 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5363 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5364 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5365 		if (err)
5366 			return err;
5367 	}
5368 
5369 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5370 	err = dquot_quota_on(sb, type, format_id, path);
5371 	if (err) {
5372 		lockdep_set_quota_inode(path->dentry->d_inode,
5373 					     I_DATA_SEM_NORMAL);
5374 	} else {
5375 		struct inode *inode = d_inode(path->dentry);
5376 		handle_t *handle;
5377 
5378 		/*
5379 		 * Set inode flags to prevent userspace from messing with quota
5380 		 * files. If this fails, we return success anyway since quotas
5381 		 * are already enabled and this is not a hard failure.
5382 		 */
5383 		inode_lock(inode);
5384 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5385 		if (IS_ERR(handle))
5386 			goto unlock_inode;
5387 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5388 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5389 				S_NOATIME | S_IMMUTABLE);
5390 		ext4_mark_inode_dirty(handle, inode);
5391 		ext4_journal_stop(handle);
5392 	unlock_inode:
5393 		inode_unlock(inode);
5394 	}
5395 	return err;
5396 }
5397 
5398 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5399 			     unsigned int flags)
5400 {
5401 	int err;
5402 	struct inode *qf_inode;
5403 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5404 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5405 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5406 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5407 	};
5408 
5409 	BUG_ON(!ext4_has_feature_quota(sb));
5410 
5411 	if (!qf_inums[type])
5412 		return -EPERM;
5413 
5414 	qf_inode = ext4_iget(sb, qf_inums[type]);
5415 	if (IS_ERR(qf_inode)) {
5416 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5417 		return PTR_ERR(qf_inode);
5418 	}
5419 
5420 	/* Don't account quota for quota files to avoid recursion */
5421 	qf_inode->i_flags |= S_NOQUOTA;
5422 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5423 	err = dquot_enable(qf_inode, type, format_id, flags);
5424 	iput(qf_inode);
5425 	if (err)
5426 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5427 
5428 	return err;
5429 }
5430 
5431 /* Enable usage tracking for all quota types. */
5432 static int ext4_enable_quotas(struct super_block *sb)
5433 {
5434 	int type, err = 0;
5435 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5436 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5437 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5438 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5439 	};
5440 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5441 		test_opt(sb, USRQUOTA),
5442 		test_opt(sb, GRPQUOTA),
5443 		test_opt(sb, PRJQUOTA),
5444 	};
5445 
5446 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5447 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5448 		if (qf_inums[type]) {
5449 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5450 				DQUOT_USAGE_ENABLED |
5451 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5452 			if (err) {
5453 				ext4_warning(sb,
5454 					"Failed to enable quota tracking "
5455 					"(type=%d, err=%d). Please run "
5456 					"e2fsck to fix.", type, err);
5457 				return err;
5458 			}
5459 		}
5460 	}
5461 	return 0;
5462 }
5463 
5464 static int ext4_quota_off(struct super_block *sb, int type)
5465 {
5466 	struct inode *inode = sb_dqopt(sb)->files[type];
5467 	handle_t *handle;
5468 	int err;
5469 
5470 	/* Force all delayed allocation blocks to be allocated.
5471 	 * Caller already holds s_umount sem */
5472 	if (test_opt(sb, DELALLOC))
5473 		sync_filesystem(sb);
5474 
5475 	if (!inode || !igrab(inode))
5476 		goto out;
5477 
5478 	err = dquot_quota_off(sb, type);
5479 	if (err)
5480 		goto out_put;
5481 
5482 	inode_lock(inode);
5483 	/*
5484 	 * Update modification times of quota files when userspace can
5485 	 * start looking at them. If we fail, we return success anyway since
5486 	 * this is not a hard failure and quotas are already disabled.
5487 	 */
5488 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5489 	if (IS_ERR(handle))
5490 		goto out_unlock;
5491 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5492 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5493 	inode->i_mtime = inode->i_ctime = current_time(inode);
5494 	ext4_mark_inode_dirty(handle, inode);
5495 	ext4_journal_stop(handle);
5496 out_unlock:
5497 	inode_unlock(inode);
5498 out_put:
5499 	iput(inode);
5500 	return err;
5501 out:
5502 	return dquot_quota_off(sb, type);
5503 }
5504 
5505 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5506  * acquiring the locks... As quota files are never truncated and quota code
5507  * itself serializes the operations (and no one else should touch the files)
5508  * we don't have to be afraid of races */
5509 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5510 			       size_t len, loff_t off)
5511 {
5512 	struct inode *inode = sb_dqopt(sb)->files[type];
5513 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5514 	int offset = off & (sb->s_blocksize - 1);
5515 	int tocopy;
5516 	size_t toread;
5517 	struct buffer_head *bh;
5518 	loff_t i_size = i_size_read(inode);
5519 
5520 	if (off > i_size)
5521 		return 0;
5522 	if (off+len > i_size)
5523 		len = i_size-off;
5524 	toread = len;
5525 	while (toread > 0) {
5526 		tocopy = sb->s_blocksize - offset < toread ?
5527 				sb->s_blocksize - offset : toread;
5528 		bh = ext4_bread(NULL, inode, blk, 0);
5529 		if (IS_ERR(bh))
5530 			return PTR_ERR(bh);
5531 		if (!bh)	/* A hole? */
5532 			memset(data, 0, tocopy);
5533 		else
5534 			memcpy(data, bh->b_data+offset, tocopy);
5535 		brelse(bh);
5536 		offset = 0;
5537 		toread -= tocopy;
5538 		data += tocopy;
5539 		blk++;
5540 	}
5541 	return len;
5542 }
5543 
5544 /* Write to quotafile (we know the transaction is already started and has
5545  * enough credits) */
5546 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5547 				const char *data, size_t len, loff_t off)
5548 {
5549 	struct inode *inode = sb_dqopt(sb)->files[type];
5550 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5551 	int err, offset = off & (sb->s_blocksize - 1);
5552 	int retries = 0;
5553 	struct buffer_head *bh;
5554 	handle_t *handle = journal_current_handle();
5555 
5556 	if (EXT4_SB(sb)->s_journal && !handle) {
5557 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5558 			" cancelled because transaction is not started",
5559 			(unsigned long long)off, (unsigned long long)len);
5560 		return -EIO;
5561 	}
5562 	/*
5563 	 * Since we account only one data block in transaction credits,
5564 	 * then it is impossible to cross a block boundary.
5565 	 */
5566 	if (sb->s_blocksize - offset < len) {
5567 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5568 			" cancelled because not block aligned",
5569 			(unsigned long long)off, (unsigned long long)len);
5570 		return -EIO;
5571 	}
5572 
5573 	do {
5574 		bh = ext4_bread(handle, inode, blk,
5575 				EXT4_GET_BLOCKS_CREATE |
5576 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5577 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5578 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5579 	if (IS_ERR(bh))
5580 		return PTR_ERR(bh);
5581 	if (!bh)
5582 		goto out;
5583 	BUFFER_TRACE(bh, "get write access");
5584 	err = ext4_journal_get_write_access(handle, bh);
5585 	if (err) {
5586 		brelse(bh);
5587 		return err;
5588 	}
5589 	lock_buffer(bh);
5590 	memcpy(bh->b_data+offset, data, len);
5591 	flush_dcache_page(bh->b_page);
5592 	unlock_buffer(bh);
5593 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5594 	brelse(bh);
5595 out:
5596 	if (inode->i_size < off + len) {
5597 		i_size_write(inode, off + len);
5598 		EXT4_I(inode)->i_disksize = inode->i_size;
5599 		ext4_mark_inode_dirty(handle, inode);
5600 	}
5601 	return len;
5602 }
5603 
5604 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5605 {
5606 	const struct quota_format_ops	*ops;
5607 
5608 	if (!sb_has_quota_loaded(sb, qid->type))
5609 		return -ESRCH;
5610 	ops = sb_dqopt(sb)->ops[qid->type];
5611 	if (!ops || !ops->get_next_id)
5612 		return -ENOSYS;
5613 	return dquot_get_next_id(sb, qid);
5614 }
5615 #endif
5616 
5617 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5618 		       const char *dev_name, void *data)
5619 {
5620 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5621 }
5622 
5623 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5624 static inline void register_as_ext2(void)
5625 {
5626 	int err = register_filesystem(&ext2_fs_type);
5627 	if (err)
5628 		printk(KERN_WARNING
5629 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5630 }
5631 
5632 static inline void unregister_as_ext2(void)
5633 {
5634 	unregister_filesystem(&ext2_fs_type);
5635 }
5636 
5637 static inline int ext2_feature_set_ok(struct super_block *sb)
5638 {
5639 	if (ext4_has_unknown_ext2_incompat_features(sb))
5640 		return 0;
5641 	if (sb->s_flags & MS_RDONLY)
5642 		return 1;
5643 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5644 		return 0;
5645 	return 1;
5646 }
5647 #else
5648 static inline void register_as_ext2(void) { }
5649 static inline void unregister_as_ext2(void) { }
5650 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5651 #endif
5652 
5653 static inline void register_as_ext3(void)
5654 {
5655 	int err = register_filesystem(&ext3_fs_type);
5656 	if (err)
5657 		printk(KERN_WARNING
5658 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5659 }
5660 
5661 static inline void unregister_as_ext3(void)
5662 {
5663 	unregister_filesystem(&ext3_fs_type);
5664 }
5665 
5666 static inline int ext3_feature_set_ok(struct super_block *sb)
5667 {
5668 	if (ext4_has_unknown_ext3_incompat_features(sb))
5669 		return 0;
5670 	if (!ext4_has_feature_journal(sb))
5671 		return 0;
5672 	if (sb->s_flags & MS_RDONLY)
5673 		return 1;
5674 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5675 		return 0;
5676 	return 1;
5677 }
5678 
5679 static struct file_system_type ext4_fs_type = {
5680 	.owner		= THIS_MODULE,
5681 	.name		= "ext4",
5682 	.mount		= ext4_mount,
5683 	.kill_sb	= kill_block_super,
5684 	.fs_flags	= FS_REQUIRES_DEV,
5685 };
5686 MODULE_ALIAS_FS("ext4");
5687 
5688 /* Shared across all ext4 file systems */
5689 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5690 
5691 static int __init ext4_init_fs(void)
5692 {
5693 	int i, err;
5694 
5695 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5696 	ext4_li_info = NULL;
5697 	mutex_init(&ext4_li_mtx);
5698 
5699 	/* Build-time check for flags consistency */
5700 	ext4_check_flag_values();
5701 
5702 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5703 		init_waitqueue_head(&ext4__ioend_wq[i]);
5704 
5705 	err = ext4_init_es();
5706 	if (err)
5707 		return err;
5708 
5709 	err = ext4_init_pageio();
5710 	if (err)
5711 		goto out5;
5712 
5713 	err = ext4_init_system_zone();
5714 	if (err)
5715 		goto out4;
5716 
5717 	err = ext4_init_sysfs();
5718 	if (err)
5719 		goto out3;
5720 
5721 	err = ext4_init_mballoc();
5722 	if (err)
5723 		goto out2;
5724 	err = init_inodecache();
5725 	if (err)
5726 		goto out1;
5727 	register_as_ext3();
5728 	register_as_ext2();
5729 	err = register_filesystem(&ext4_fs_type);
5730 	if (err)
5731 		goto out;
5732 
5733 	return 0;
5734 out:
5735 	unregister_as_ext2();
5736 	unregister_as_ext3();
5737 	destroy_inodecache();
5738 out1:
5739 	ext4_exit_mballoc();
5740 out2:
5741 	ext4_exit_sysfs();
5742 out3:
5743 	ext4_exit_system_zone();
5744 out4:
5745 	ext4_exit_pageio();
5746 out5:
5747 	ext4_exit_es();
5748 
5749 	return err;
5750 }
5751 
5752 static void __exit ext4_exit_fs(void)
5753 {
5754 	ext4_destroy_lazyinit_thread();
5755 	unregister_as_ext2();
5756 	unregister_as_ext3();
5757 	unregister_filesystem(&ext4_fs_type);
5758 	destroy_inodecache();
5759 	ext4_exit_mballoc();
5760 	ext4_exit_sysfs();
5761 	ext4_exit_system_zone();
5762 	ext4_exit_pageio();
5763 	ext4_exit_es();
5764 }
5765 
5766 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5767 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5768 MODULE_LICENSE("GPL");
5769 module_init(ext4_init_fs)
5770 module_exit(ext4_exit_fs)
5771