xref: /linux/fs/ext4/super.c (revision 92ce4c3ea7c44e61ca2b6ef3e5682bfcea851d87)
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/dax.h>
41 #include <linux/cleancache.h>
42 #include <linux/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 #include "fsmap.h"
54 
55 #define CREATE_TRACE_POINTS
56 #include <trace/events/ext4.h>
57 
58 static struct ext4_lazy_init *ext4_li_info;
59 static struct mutex ext4_li_mtx;
60 static struct ratelimit_state ext4_mount_msg_ratelimit;
61 
62 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
63 			     unsigned long journal_devnum);
64 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
65 static int ext4_commit_super(struct super_block *sb, int sync);
66 static void ext4_mark_recovery_complete(struct super_block *sb,
67 					struct ext4_super_block *es);
68 static void ext4_clear_journal_err(struct super_block *sb,
69 				   struct ext4_super_block *es);
70 static int ext4_sync_fs(struct super_block *sb, int wait);
71 static int ext4_remount(struct super_block *sb, int *flags, char *data);
72 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
73 static int ext4_unfreeze(struct super_block *sb);
74 static int ext4_freeze(struct super_block *sb);
75 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
76 		       const char *dev_name, void *data);
77 static inline int ext2_feature_set_ok(struct super_block *sb);
78 static inline int ext3_feature_set_ok(struct super_block *sb);
79 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
80 static void ext4_destroy_lazyinit_thread(void);
81 static void ext4_unregister_li_request(struct super_block *sb);
82 static void ext4_clear_request_list(void);
83 static struct inode *ext4_get_journal_inode(struct super_block *sb,
84 					    unsigned int journal_inum);
85 
86 /*
87  * Lock ordering
88  *
89  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
90  * i_mmap_rwsem (inode->i_mmap_rwsem)!
91  *
92  * page fault path:
93  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
94  *   page lock -> i_data_sem (rw)
95  *
96  * buffered write path:
97  * sb_start_write -> i_mutex -> mmap_sem
98  * sb_start_write -> i_mutex -> transaction start -> page lock ->
99  *   i_data_sem (rw)
100  *
101  * truncate:
102  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
103  *   i_mmap_rwsem (w) -> page lock
104  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
105  *   transaction start -> i_data_sem (rw)
106  *
107  * direct IO:
108  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
109  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
110  *   transaction start -> i_data_sem (rw)
111  *
112  * writepages:
113  * transaction start -> page lock(s) -> i_data_sem (rw)
114  */
115 
116 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
117 static struct file_system_type ext2_fs_type = {
118 	.owner		= THIS_MODULE,
119 	.name		= "ext2",
120 	.mount		= ext4_mount,
121 	.kill_sb	= kill_block_super,
122 	.fs_flags	= FS_REQUIRES_DEV,
123 };
124 MODULE_ALIAS_FS("ext2");
125 MODULE_ALIAS("ext2");
126 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
127 #else
128 #define IS_EXT2_SB(sb) (0)
129 #endif
130 
131 
132 static struct file_system_type ext3_fs_type = {
133 	.owner		= THIS_MODULE,
134 	.name		= "ext3",
135 	.mount		= ext4_mount,
136 	.kill_sb	= kill_block_super,
137 	.fs_flags	= FS_REQUIRES_DEV,
138 };
139 MODULE_ALIAS_FS("ext3");
140 MODULE_ALIAS("ext3");
141 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
142 
143 static int ext4_verify_csum_type(struct super_block *sb,
144 				 struct ext4_super_block *es)
145 {
146 	if (!ext4_has_feature_metadata_csum(sb))
147 		return 1;
148 
149 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
150 }
151 
152 static __le32 ext4_superblock_csum(struct super_block *sb,
153 				   struct ext4_super_block *es)
154 {
155 	struct ext4_sb_info *sbi = EXT4_SB(sb);
156 	int offset = offsetof(struct ext4_super_block, s_checksum);
157 	__u32 csum;
158 
159 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
160 
161 	return cpu_to_le32(csum);
162 }
163 
164 static int ext4_superblock_csum_verify(struct super_block *sb,
165 				       struct ext4_super_block *es)
166 {
167 	if (!ext4_has_metadata_csum(sb))
168 		return 1;
169 
170 	return es->s_checksum == ext4_superblock_csum(sb, es);
171 }
172 
173 void ext4_superblock_csum_set(struct super_block *sb)
174 {
175 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
176 
177 	if (!ext4_has_metadata_csum(sb))
178 		return;
179 
180 	es->s_checksum = ext4_superblock_csum(sb, es);
181 }
182 
183 void *ext4_kvmalloc(size_t size, gfp_t flags)
184 {
185 	void *ret;
186 
187 	ret = kmalloc(size, flags | __GFP_NOWARN);
188 	if (!ret)
189 		ret = __vmalloc(size, flags, PAGE_KERNEL);
190 	return ret;
191 }
192 
193 void *ext4_kvzalloc(size_t size, gfp_t flags)
194 {
195 	void *ret;
196 
197 	ret = kzalloc(size, flags | __GFP_NOWARN);
198 	if (!ret)
199 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
200 	return ret;
201 }
202 
203 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
204 			       struct ext4_group_desc *bg)
205 {
206 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
207 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
208 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
209 }
210 
211 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
212 			       struct ext4_group_desc *bg)
213 {
214 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
215 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
216 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
217 }
218 
219 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
220 			      struct ext4_group_desc *bg)
221 {
222 	return le32_to_cpu(bg->bg_inode_table_lo) |
223 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
224 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
225 }
226 
227 __u32 ext4_free_group_clusters(struct super_block *sb,
228 			       struct ext4_group_desc *bg)
229 {
230 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
231 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
232 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
233 }
234 
235 __u32 ext4_free_inodes_count(struct super_block *sb,
236 			      struct ext4_group_desc *bg)
237 {
238 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
239 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
240 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
241 }
242 
243 __u32 ext4_used_dirs_count(struct super_block *sb,
244 			      struct ext4_group_desc *bg)
245 {
246 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
247 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
248 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
249 }
250 
251 __u32 ext4_itable_unused_count(struct super_block *sb,
252 			      struct ext4_group_desc *bg)
253 {
254 	return le16_to_cpu(bg->bg_itable_unused_lo) |
255 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
256 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
257 }
258 
259 void ext4_block_bitmap_set(struct super_block *sb,
260 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
261 {
262 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
263 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
264 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
265 }
266 
267 void ext4_inode_bitmap_set(struct super_block *sb,
268 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
269 {
270 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
271 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
272 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
273 }
274 
275 void ext4_inode_table_set(struct super_block *sb,
276 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
277 {
278 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
279 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
280 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
281 }
282 
283 void ext4_free_group_clusters_set(struct super_block *sb,
284 				  struct ext4_group_desc *bg, __u32 count)
285 {
286 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
287 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
288 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
289 }
290 
291 void ext4_free_inodes_set(struct super_block *sb,
292 			  struct ext4_group_desc *bg, __u32 count)
293 {
294 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
295 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
296 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
297 }
298 
299 void ext4_used_dirs_set(struct super_block *sb,
300 			  struct ext4_group_desc *bg, __u32 count)
301 {
302 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
303 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
304 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
305 }
306 
307 void ext4_itable_unused_set(struct super_block *sb,
308 			  struct ext4_group_desc *bg, __u32 count)
309 {
310 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
311 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
312 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
313 }
314 
315 
316 static void __save_error_info(struct super_block *sb, const char *func,
317 			    unsigned int line)
318 {
319 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
320 
321 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
322 	if (bdev_read_only(sb->s_bdev))
323 		return;
324 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
325 	es->s_last_error_time = cpu_to_le32(get_seconds());
326 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
327 	es->s_last_error_line = cpu_to_le32(line);
328 	if (!es->s_first_error_time) {
329 		es->s_first_error_time = es->s_last_error_time;
330 		strncpy(es->s_first_error_func, func,
331 			sizeof(es->s_first_error_func));
332 		es->s_first_error_line = cpu_to_le32(line);
333 		es->s_first_error_ino = es->s_last_error_ino;
334 		es->s_first_error_block = es->s_last_error_block;
335 	}
336 	/*
337 	 * Start the daily error reporting function if it hasn't been
338 	 * started already
339 	 */
340 	if (!es->s_error_count)
341 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
342 	le32_add_cpu(&es->s_error_count, 1);
343 }
344 
345 static void save_error_info(struct super_block *sb, const char *func,
346 			    unsigned int line)
347 {
348 	__save_error_info(sb, func, line);
349 	ext4_commit_super(sb, 1);
350 }
351 
352 /*
353  * The del_gendisk() function uninitializes the disk-specific data
354  * structures, including the bdi structure, without telling anyone
355  * else.  Once this happens, any attempt to call mark_buffer_dirty()
356  * (for example, by ext4_commit_super), will cause a kernel OOPS.
357  * This is a kludge to prevent these oops until we can put in a proper
358  * hook in del_gendisk() to inform the VFS and file system layers.
359  */
360 static int block_device_ejected(struct super_block *sb)
361 {
362 	struct inode *bd_inode = sb->s_bdev->bd_inode;
363 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
364 
365 	return bdi->dev == NULL;
366 }
367 
368 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
369 {
370 	struct super_block		*sb = journal->j_private;
371 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
372 	int				error = is_journal_aborted(journal);
373 	struct ext4_journal_cb_entry	*jce;
374 
375 	BUG_ON(txn->t_state == T_FINISHED);
376 
377 	ext4_process_freed_data(sb, txn->t_tid);
378 
379 	spin_lock(&sbi->s_md_lock);
380 	while (!list_empty(&txn->t_private_list)) {
381 		jce = list_entry(txn->t_private_list.next,
382 				 struct ext4_journal_cb_entry, jce_list);
383 		list_del_init(&jce->jce_list);
384 		spin_unlock(&sbi->s_md_lock);
385 		jce->jce_func(sb, jce, error);
386 		spin_lock(&sbi->s_md_lock);
387 	}
388 	spin_unlock(&sbi->s_md_lock);
389 }
390 
391 /* Deal with the reporting of failure conditions on a filesystem such as
392  * inconsistencies detected or read IO failures.
393  *
394  * On ext2, we can store the error state of the filesystem in the
395  * superblock.  That is not possible on ext4, because we may have other
396  * write ordering constraints on the superblock which prevent us from
397  * writing it out straight away; and given that the journal is about to
398  * be aborted, we can't rely on the current, or future, transactions to
399  * write out the superblock safely.
400  *
401  * We'll just use the jbd2_journal_abort() error code to record an error in
402  * the journal instead.  On recovery, the journal will complain about
403  * that error until we've noted it down and cleared it.
404  */
405 
406 static void ext4_handle_error(struct super_block *sb)
407 {
408 	if (sb->s_flags & MS_RDONLY)
409 		return;
410 
411 	if (!test_opt(sb, ERRORS_CONT)) {
412 		journal_t *journal = EXT4_SB(sb)->s_journal;
413 
414 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
415 		if (journal)
416 			jbd2_journal_abort(journal, -EIO);
417 	}
418 	if (test_opt(sb, ERRORS_RO)) {
419 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
420 		/*
421 		 * Make sure updated value of ->s_mount_flags will be visible
422 		 * before ->s_flags update
423 		 */
424 		smp_wmb();
425 		sb->s_flags |= MS_RDONLY;
426 	}
427 	if (test_opt(sb, ERRORS_PANIC)) {
428 		if (EXT4_SB(sb)->s_journal &&
429 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
430 			return;
431 		panic("EXT4-fs (device %s): panic forced after error\n",
432 			sb->s_id);
433 	}
434 }
435 
436 #define ext4_error_ratelimit(sb)					\
437 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
438 			     "EXT4-fs error")
439 
440 void __ext4_error(struct super_block *sb, const char *function,
441 		  unsigned int line, const char *fmt, ...)
442 {
443 	struct va_format vaf;
444 	va_list args;
445 
446 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
447 		return;
448 
449 	if (ext4_error_ratelimit(sb)) {
450 		va_start(args, fmt);
451 		vaf.fmt = fmt;
452 		vaf.va = &args;
453 		printk(KERN_CRIT
454 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
455 		       sb->s_id, function, line, current->comm, &vaf);
456 		va_end(args);
457 	}
458 	save_error_info(sb, function, line);
459 	ext4_handle_error(sb);
460 }
461 
462 void __ext4_error_inode(struct inode *inode, const char *function,
463 			unsigned int line, ext4_fsblk_t block,
464 			const char *fmt, ...)
465 {
466 	va_list args;
467 	struct va_format vaf;
468 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
469 
470 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
471 		return;
472 
473 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
474 	es->s_last_error_block = cpu_to_le64(block);
475 	if (ext4_error_ratelimit(inode->i_sb)) {
476 		va_start(args, fmt);
477 		vaf.fmt = fmt;
478 		vaf.va = &args;
479 		if (block)
480 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
481 			       "inode #%lu: block %llu: comm %s: %pV\n",
482 			       inode->i_sb->s_id, function, line, inode->i_ino,
483 			       block, current->comm, &vaf);
484 		else
485 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
486 			       "inode #%lu: comm %s: %pV\n",
487 			       inode->i_sb->s_id, function, line, inode->i_ino,
488 			       current->comm, &vaf);
489 		va_end(args);
490 	}
491 	save_error_info(inode->i_sb, function, line);
492 	ext4_handle_error(inode->i_sb);
493 }
494 
495 void __ext4_error_file(struct file *file, const char *function,
496 		       unsigned int line, ext4_fsblk_t block,
497 		       const char *fmt, ...)
498 {
499 	va_list args;
500 	struct va_format vaf;
501 	struct ext4_super_block *es;
502 	struct inode *inode = file_inode(file);
503 	char pathname[80], *path;
504 
505 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
506 		return;
507 
508 	es = EXT4_SB(inode->i_sb)->s_es;
509 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
510 	if (ext4_error_ratelimit(inode->i_sb)) {
511 		path = file_path(file, pathname, sizeof(pathname));
512 		if (IS_ERR(path))
513 			path = "(unknown)";
514 		va_start(args, fmt);
515 		vaf.fmt = fmt;
516 		vaf.va = &args;
517 		if (block)
518 			printk(KERN_CRIT
519 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
520 			       "block %llu: comm %s: path %s: %pV\n",
521 			       inode->i_sb->s_id, function, line, inode->i_ino,
522 			       block, current->comm, path, &vaf);
523 		else
524 			printk(KERN_CRIT
525 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
526 			       "comm %s: path %s: %pV\n",
527 			       inode->i_sb->s_id, function, line, inode->i_ino,
528 			       current->comm, path, &vaf);
529 		va_end(args);
530 	}
531 	save_error_info(inode->i_sb, function, line);
532 	ext4_handle_error(inode->i_sb);
533 }
534 
535 const char *ext4_decode_error(struct super_block *sb, int errno,
536 			      char nbuf[16])
537 {
538 	char *errstr = NULL;
539 
540 	switch (errno) {
541 	case -EFSCORRUPTED:
542 		errstr = "Corrupt filesystem";
543 		break;
544 	case -EFSBADCRC:
545 		errstr = "Filesystem failed CRC";
546 		break;
547 	case -EIO:
548 		errstr = "IO failure";
549 		break;
550 	case -ENOMEM:
551 		errstr = "Out of memory";
552 		break;
553 	case -EROFS:
554 		if (!sb || (EXT4_SB(sb)->s_journal &&
555 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
556 			errstr = "Journal has aborted";
557 		else
558 			errstr = "Readonly filesystem";
559 		break;
560 	default:
561 		/* If the caller passed in an extra buffer for unknown
562 		 * errors, textualise them now.  Else we just return
563 		 * NULL. */
564 		if (nbuf) {
565 			/* Check for truncated error codes... */
566 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
567 				errstr = nbuf;
568 		}
569 		break;
570 	}
571 
572 	return errstr;
573 }
574 
575 /* __ext4_std_error decodes expected errors from journaling functions
576  * automatically and invokes the appropriate error response.  */
577 
578 void __ext4_std_error(struct super_block *sb, const char *function,
579 		      unsigned int line, int errno)
580 {
581 	char nbuf[16];
582 	const char *errstr;
583 
584 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
585 		return;
586 
587 	/* Special case: if the error is EROFS, and we're not already
588 	 * inside a transaction, then there's really no point in logging
589 	 * an error. */
590 	if (errno == -EROFS && journal_current_handle() == NULL &&
591 	    (sb->s_flags & MS_RDONLY))
592 		return;
593 
594 	if (ext4_error_ratelimit(sb)) {
595 		errstr = ext4_decode_error(sb, errno, nbuf);
596 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
597 		       sb->s_id, function, line, errstr);
598 	}
599 
600 	save_error_info(sb, function, line);
601 	ext4_handle_error(sb);
602 }
603 
604 /*
605  * ext4_abort is a much stronger failure handler than ext4_error.  The
606  * abort function may be used to deal with unrecoverable failures such
607  * as journal IO errors or ENOMEM at a critical moment in log management.
608  *
609  * We unconditionally force the filesystem into an ABORT|READONLY state,
610  * unless the error response on the fs has been set to panic in which
611  * case we take the easy way out and panic immediately.
612  */
613 
614 void __ext4_abort(struct super_block *sb, const char *function,
615 		unsigned int line, const char *fmt, ...)
616 {
617 	struct va_format vaf;
618 	va_list args;
619 
620 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
621 		return;
622 
623 	save_error_info(sb, function, line);
624 	va_start(args, fmt);
625 	vaf.fmt = fmt;
626 	vaf.va = &args;
627 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
628 	       sb->s_id, function, line, &vaf);
629 	va_end(args);
630 
631 	if ((sb->s_flags & MS_RDONLY) == 0) {
632 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
633 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
634 		/*
635 		 * Make sure updated value of ->s_mount_flags will be visible
636 		 * before ->s_flags update
637 		 */
638 		smp_wmb();
639 		sb->s_flags |= MS_RDONLY;
640 		if (EXT4_SB(sb)->s_journal)
641 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
642 		save_error_info(sb, function, line);
643 	}
644 	if (test_opt(sb, ERRORS_PANIC)) {
645 		if (EXT4_SB(sb)->s_journal &&
646 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
647 			return;
648 		panic("EXT4-fs panic from previous error\n");
649 	}
650 }
651 
652 void __ext4_msg(struct super_block *sb,
653 		const char *prefix, const char *fmt, ...)
654 {
655 	struct va_format vaf;
656 	va_list args;
657 
658 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
659 		return;
660 
661 	va_start(args, fmt);
662 	vaf.fmt = fmt;
663 	vaf.va = &args;
664 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
665 	va_end(args);
666 }
667 
668 #define ext4_warning_ratelimit(sb)					\
669 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
670 			     "EXT4-fs warning")
671 
672 void __ext4_warning(struct super_block *sb, const char *function,
673 		    unsigned int line, const char *fmt, ...)
674 {
675 	struct va_format vaf;
676 	va_list args;
677 
678 	if (!ext4_warning_ratelimit(sb))
679 		return;
680 
681 	va_start(args, fmt);
682 	vaf.fmt = fmt;
683 	vaf.va = &args;
684 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
685 	       sb->s_id, function, line, &vaf);
686 	va_end(args);
687 }
688 
689 void __ext4_warning_inode(const struct inode *inode, const char *function,
690 			  unsigned int line, const char *fmt, ...)
691 {
692 	struct va_format vaf;
693 	va_list args;
694 
695 	if (!ext4_warning_ratelimit(inode->i_sb))
696 		return;
697 
698 	va_start(args, fmt);
699 	vaf.fmt = fmt;
700 	vaf.va = &args;
701 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
702 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
703 	       function, line, inode->i_ino, current->comm, &vaf);
704 	va_end(args);
705 }
706 
707 void __ext4_grp_locked_error(const char *function, unsigned int line,
708 			     struct super_block *sb, ext4_group_t grp,
709 			     unsigned long ino, ext4_fsblk_t block,
710 			     const char *fmt, ...)
711 __releases(bitlock)
712 __acquires(bitlock)
713 {
714 	struct va_format vaf;
715 	va_list args;
716 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
717 
718 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
719 		return;
720 
721 	es->s_last_error_ino = cpu_to_le32(ino);
722 	es->s_last_error_block = cpu_to_le64(block);
723 	__save_error_info(sb, function, line);
724 
725 	if (ext4_error_ratelimit(sb)) {
726 		va_start(args, fmt);
727 		vaf.fmt = fmt;
728 		vaf.va = &args;
729 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
730 		       sb->s_id, function, line, grp);
731 		if (ino)
732 			printk(KERN_CONT "inode %lu: ", ino);
733 		if (block)
734 			printk(KERN_CONT "block %llu:",
735 			       (unsigned long long) block);
736 		printk(KERN_CONT "%pV\n", &vaf);
737 		va_end(args);
738 	}
739 
740 	if (test_opt(sb, ERRORS_CONT)) {
741 		ext4_commit_super(sb, 0);
742 		return;
743 	}
744 
745 	ext4_unlock_group(sb, grp);
746 	ext4_handle_error(sb);
747 	/*
748 	 * We only get here in the ERRORS_RO case; relocking the group
749 	 * may be dangerous, but nothing bad will happen since the
750 	 * filesystem will have already been marked read/only and the
751 	 * journal has been aborted.  We return 1 as a hint to callers
752 	 * who might what to use the return value from
753 	 * ext4_grp_locked_error() to distinguish between the
754 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
755 	 * aggressively from the ext4 function in question, with a
756 	 * more appropriate error code.
757 	 */
758 	ext4_lock_group(sb, grp);
759 	return;
760 }
761 
762 void ext4_update_dynamic_rev(struct super_block *sb)
763 {
764 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
765 
766 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
767 		return;
768 
769 	ext4_warning(sb,
770 		     "updating to rev %d because of new feature flag, "
771 		     "running e2fsck is recommended",
772 		     EXT4_DYNAMIC_REV);
773 
774 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
775 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
776 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
777 	/* leave es->s_feature_*compat flags alone */
778 	/* es->s_uuid will be set by e2fsck if empty */
779 
780 	/*
781 	 * The rest of the superblock fields should be zero, and if not it
782 	 * means they are likely already in use, so leave them alone.  We
783 	 * can leave it up to e2fsck to clean up any inconsistencies there.
784 	 */
785 }
786 
787 /*
788  * Open the external journal device
789  */
790 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
791 {
792 	struct block_device *bdev;
793 	char b[BDEVNAME_SIZE];
794 
795 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
796 	if (IS_ERR(bdev))
797 		goto fail;
798 	return bdev;
799 
800 fail:
801 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
802 			__bdevname(dev, b), PTR_ERR(bdev));
803 	return NULL;
804 }
805 
806 /*
807  * Release the journal device
808  */
809 static void ext4_blkdev_put(struct block_device *bdev)
810 {
811 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
812 }
813 
814 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
815 {
816 	struct block_device *bdev;
817 	bdev = sbi->journal_bdev;
818 	if (bdev) {
819 		ext4_blkdev_put(bdev);
820 		sbi->journal_bdev = NULL;
821 	}
822 }
823 
824 static inline struct inode *orphan_list_entry(struct list_head *l)
825 {
826 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
827 }
828 
829 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
830 {
831 	struct list_head *l;
832 
833 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
834 		 le32_to_cpu(sbi->s_es->s_last_orphan));
835 
836 	printk(KERN_ERR "sb_info orphan list:\n");
837 	list_for_each(l, &sbi->s_orphan) {
838 		struct inode *inode = orphan_list_entry(l);
839 		printk(KERN_ERR "  "
840 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
841 		       inode->i_sb->s_id, inode->i_ino, inode,
842 		       inode->i_mode, inode->i_nlink,
843 		       NEXT_ORPHAN(inode));
844 	}
845 }
846 
847 #ifdef CONFIG_QUOTA
848 static int ext4_quota_off(struct super_block *sb, int type);
849 
850 static inline void ext4_quota_off_umount(struct super_block *sb)
851 {
852 	int type;
853 
854 	/* Use our quota_off function to clear inode flags etc. */
855 	for (type = 0; type < EXT4_MAXQUOTAS; type++)
856 		ext4_quota_off(sb, type);
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_ea_inode_cache) {
934 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
935 		sbi->s_ea_inode_cache = NULL;
936 	}
937 	if (sbi->s_ea_block_cache) {
938 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
939 		sbi->s_ea_block_cache = NULL;
940 	}
941 	if (sbi->s_mmp_tsk)
942 		kthread_stop(sbi->s_mmp_tsk);
943 	brelse(sbi->s_sbh);
944 	sb->s_fs_info = NULL;
945 	/*
946 	 * Now that we are completely done shutting down the
947 	 * superblock, we need to actually destroy the kobject.
948 	 */
949 	kobject_put(&sbi->s_kobj);
950 	wait_for_completion(&sbi->s_kobj_unregister);
951 	if (sbi->s_chksum_driver)
952 		crypto_free_shash(sbi->s_chksum_driver);
953 	kfree(sbi->s_blockgroup_lock);
954 	kfree(sbi);
955 }
956 
957 static struct kmem_cache *ext4_inode_cachep;
958 
959 /*
960  * Called inside transaction, so use GFP_NOFS
961  */
962 static struct inode *ext4_alloc_inode(struct super_block *sb)
963 {
964 	struct ext4_inode_info *ei;
965 
966 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
967 	if (!ei)
968 		return NULL;
969 
970 	ei->vfs_inode.i_version = 1;
971 	spin_lock_init(&ei->i_raw_lock);
972 	INIT_LIST_HEAD(&ei->i_prealloc_list);
973 	spin_lock_init(&ei->i_prealloc_lock);
974 	ext4_es_init_tree(&ei->i_es_tree);
975 	rwlock_init(&ei->i_es_lock);
976 	INIT_LIST_HEAD(&ei->i_es_list);
977 	ei->i_es_all_nr = 0;
978 	ei->i_es_shk_nr = 0;
979 	ei->i_es_shrink_lblk = 0;
980 	ei->i_reserved_data_blocks = 0;
981 	ei->i_da_metadata_calc_len = 0;
982 	ei->i_da_metadata_calc_last_lblock = 0;
983 	spin_lock_init(&(ei->i_block_reservation_lock));
984 #ifdef CONFIG_QUOTA
985 	ei->i_reserved_quota = 0;
986 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
987 #endif
988 	ei->jinode = NULL;
989 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
990 	spin_lock_init(&ei->i_completed_io_lock);
991 	ei->i_sync_tid = 0;
992 	ei->i_datasync_tid = 0;
993 	atomic_set(&ei->i_unwritten, 0);
994 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
995 	return &ei->vfs_inode;
996 }
997 
998 static int ext4_drop_inode(struct inode *inode)
999 {
1000 	int drop = generic_drop_inode(inode);
1001 
1002 	trace_ext4_drop_inode(inode, drop);
1003 	return drop;
1004 }
1005 
1006 static void ext4_i_callback(struct rcu_head *head)
1007 {
1008 	struct inode *inode = container_of(head, struct inode, i_rcu);
1009 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1010 }
1011 
1012 static void ext4_destroy_inode(struct inode *inode)
1013 {
1014 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1015 		ext4_msg(inode->i_sb, KERN_ERR,
1016 			 "Inode %lu (%p): orphan list check failed!",
1017 			 inode->i_ino, EXT4_I(inode));
1018 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1019 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1020 				true);
1021 		dump_stack();
1022 	}
1023 	call_rcu(&inode->i_rcu, ext4_i_callback);
1024 }
1025 
1026 static void init_once(void *foo)
1027 {
1028 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1029 
1030 	INIT_LIST_HEAD(&ei->i_orphan);
1031 	init_rwsem(&ei->xattr_sem);
1032 	init_rwsem(&ei->i_data_sem);
1033 	init_rwsem(&ei->i_mmap_sem);
1034 	inode_init_once(&ei->vfs_inode);
1035 }
1036 
1037 static int __init init_inodecache(void)
1038 {
1039 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1040 					     sizeof(struct ext4_inode_info),
1041 					     0, (SLAB_RECLAIM_ACCOUNT|
1042 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1043 					     init_once);
1044 	if (ext4_inode_cachep == NULL)
1045 		return -ENOMEM;
1046 	return 0;
1047 }
1048 
1049 static void destroy_inodecache(void)
1050 {
1051 	/*
1052 	 * Make sure all delayed rcu free inodes are flushed before we
1053 	 * destroy cache.
1054 	 */
1055 	rcu_barrier();
1056 	kmem_cache_destroy(ext4_inode_cachep);
1057 }
1058 
1059 void ext4_clear_inode(struct inode *inode)
1060 {
1061 	invalidate_inode_buffers(inode);
1062 	clear_inode(inode);
1063 	dquot_drop(inode);
1064 	ext4_discard_preallocations(inode);
1065 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1066 	if (EXT4_I(inode)->jinode) {
1067 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1068 					       EXT4_I(inode)->jinode);
1069 		jbd2_free_inode(EXT4_I(inode)->jinode);
1070 		EXT4_I(inode)->jinode = NULL;
1071 	}
1072 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1073 	fscrypt_put_encryption_info(inode, NULL);
1074 #endif
1075 }
1076 
1077 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1078 					u64 ino, u32 generation)
1079 {
1080 	struct inode *inode;
1081 
1082 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1083 		return ERR_PTR(-ESTALE);
1084 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1085 		return ERR_PTR(-ESTALE);
1086 
1087 	/* iget isn't really right if the inode is currently unallocated!!
1088 	 *
1089 	 * ext4_read_inode will return a bad_inode if the inode had been
1090 	 * deleted, so we should be safe.
1091 	 *
1092 	 * Currently we don't know the generation for parent directory, so
1093 	 * a generation of 0 means "accept any"
1094 	 */
1095 	inode = ext4_iget_normal(sb, ino);
1096 	if (IS_ERR(inode))
1097 		return ERR_CAST(inode);
1098 	if (generation && inode->i_generation != generation) {
1099 		iput(inode);
1100 		return ERR_PTR(-ESTALE);
1101 	}
1102 
1103 	return inode;
1104 }
1105 
1106 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1107 					int fh_len, int fh_type)
1108 {
1109 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1110 				    ext4_nfs_get_inode);
1111 }
1112 
1113 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1114 					int fh_len, int fh_type)
1115 {
1116 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1117 				    ext4_nfs_get_inode);
1118 }
1119 
1120 /*
1121  * Try to release metadata pages (indirect blocks, directories) which are
1122  * mapped via the block device.  Since these pages could have journal heads
1123  * which would prevent try_to_free_buffers() from freeing them, we must use
1124  * jbd2 layer's try_to_free_buffers() function to release them.
1125  */
1126 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1127 				 gfp_t wait)
1128 {
1129 	journal_t *journal = EXT4_SB(sb)->s_journal;
1130 
1131 	WARN_ON(PageChecked(page));
1132 	if (!page_has_buffers(page))
1133 		return 0;
1134 	if (journal)
1135 		return jbd2_journal_try_to_free_buffers(journal, page,
1136 						wait & ~__GFP_DIRECT_RECLAIM);
1137 	return try_to_free_buffers(page);
1138 }
1139 
1140 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1141 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1142 {
1143 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1144 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1145 }
1146 
1147 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1148 							void *fs_data)
1149 {
1150 	handle_t *handle = fs_data;
1151 	int res, res2, credits, retries = 0;
1152 
1153 	/*
1154 	 * Encrypting the root directory is not allowed because e2fsck expects
1155 	 * lost+found to exist and be unencrypted, and encrypting the root
1156 	 * directory would imply encrypting the lost+found directory as well as
1157 	 * the filename "lost+found" itself.
1158 	 */
1159 	if (inode->i_ino == EXT4_ROOT_INO)
1160 		return -EPERM;
1161 
1162 	res = ext4_convert_inline_data(inode);
1163 	if (res)
1164 		return res;
1165 
1166 	/*
1167 	 * If a journal handle was specified, then the encryption context is
1168 	 * being set on a new inode via inheritance and is part of a larger
1169 	 * transaction to create the inode.  Otherwise the encryption context is
1170 	 * being set on an existing inode in its own transaction.  Only in the
1171 	 * latter case should the "retry on ENOSPC" logic be used.
1172 	 */
1173 
1174 	if (handle) {
1175 		res = ext4_xattr_set_handle(handle, inode,
1176 					    EXT4_XATTR_INDEX_ENCRYPTION,
1177 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1178 					    ctx, len, 0);
1179 		if (!res) {
1180 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1181 			ext4_clear_inode_state(inode,
1182 					EXT4_STATE_MAY_INLINE_DATA);
1183 			/*
1184 			 * Update inode->i_flags - e.g. S_DAX may get disabled
1185 			 */
1186 			ext4_set_inode_flags(inode);
1187 		}
1188 		return res;
1189 	}
1190 
1191 	res = dquot_initialize(inode);
1192 	if (res)
1193 		return res;
1194 retry:
1195 	res = ext4_xattr_set_credits(inode, len, false /* is_create */,
1196 				     &credits);
1197 	if (res)
1198 		return res;
1199 
1200 	handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
1201 	if (IS_ERR(handle))
1202 		return PTR_ERR(handle);
1203 
1204 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1205 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1206 				    ctx, len, 0);
1207 	if (!res) {
1208 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1209 		/* Update inode->i_flags - e.g. S_DAX may get disabled */
1210 		ext4_set_inode_flags(inode);
1211 		res = ext4_mark_inode_dirty(handle, inode);
1212 		if (res)
1213 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1214 	}
1215 	res2 = ext4_journal_stop(handle);
1216 
1217 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1218 		goto retry;
1219 	if (!res)
1220 		res = res2;
1221 	return res;
1222 }
1223 
1224 static bool ext4_dummy_context(struct inode *inode)
1225 {
1226 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1227 }
1228 
1229 static unsigned ext4_max_namelen(struct inode *inode)
1230 {
1231 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1232 		EXT4_NAME_LEN;
1233 }
1234 
1235 static const struct fscrypt_operations ext4_cryptops = {
1236 	.key_prefix		= "ext4:",
1237 	.get_context		= ext4_get_context,
1238 	.set_context		= ext4_set_context,
1239 	.dummy_context		= ext4_dummy_context,
1240 	.is_encrypted		= ext4_encrypted_inode,
1241 	.empty_dir		= ext4_empty_dir,
1242 	.max_namelen		= ext4_max_namelen,
1243 };
1244 #else
1245 static const struct fscrypt_operations ext4_cryptops = {
1246 	.is_encrypted		= ext4_encrypted_inode,
1247 };
1248 #endif
1249 
1250 #ifdef CONFIG_QUOTA
1251 static const char * const quotatypes[] = INITQFNAMES;
1252 #define QTYPE2NAME(t) (quotatypes[t])
1253 
1254 static int ext4_write_dquot(struct dquot *dquot);
1255 static int ext4_acquire_dquot(struct dquot *dquot);
1256 static int ext4_release_dquot(struct dquot *dquot);
1257 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1258 static int ext4_write_info(struct super_block *sb, int type);
1259 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1260 			 const struct path *path);
1261 static int ext4_quota_on_mount(struct super_block *sb, int type);
1262 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1263 			       size_t len, loff_t off);
1264 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1265 				const char *data, size_t len, loff_t off);
1266 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1267 			     unsigned int flags);
1268 static int ext4_enable_quotas(struct super_block *sb);
1269 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1270 
1271 static struct dquot **ext4_get_dquots(struct inode *inode)
1272 {
1273 	return EXT4_I(inode)->i_dquot;
1274 }
1275 
1276 static const struct dquot_operations ext4_quota_operations = {
1277 	.get_reserved_space	= ext4_get_reserved_space,
1278 	.write_dquot		= ext4_write_dquot,
1279 	.acquire_dquot		= ext4_acquire_dquot,
1280 	.release_dquot		= ext4_release_dquot,
1281 	.mark_dirty		= ext4_mark_dquot_dirty,
1282 	.write_info		= ext4_write_info,
1283 	.alloc_dquot		= dquot_alloc,
1284 	.destroy_dquot		= dquot_destroy,
1285 	.get_projid		= ext4_get_projid,
1286 	.get_inode_usage	= ext4_get_inode_usage,
1287 	.get_next_id		= ext4_get_next_id,
1288 };
1289 
1290 static const struct quotactl_ops ext4_qctl_operations = {
1291 	.quota_on	= ext4_quota_on,
1292 	.quota_off	= ext4_quota_off,
1293 	.quota_sync	= dquot_quota_sync,
1294 	.get_state	= dquot_get_state,
1295 	.set_info	= dquot_set_dqinfo,
1296 	.get_dqblk	= dquot_get_dqblk,
1297 	.set_dqblk	= dquot_set_dqblk,
1298 	.get_nextdqblk	= dquot_get_next_dqblk,
1299 };
1300 #endif
1301 
1302 static const struct super_operations ext4_sops = {
1303 	.alloc_inode	= ext4_alloc_inode,
1304 	.destroy_inode	= ext4_destroy_inode,
1305 	.write_inode	= ext4_write_inode,
1306 	.dirty_inode	= ext4_dirty_inode,
1307 	.drop_inode	= ext4_drop_inode,
1308 	.evict_inode	= ext4_evict_inode,
1309 	.put_super	= ext4_put_super,
1310 	.sync_fs	= ext4_sync_fs,
1311 	.freeze_fs	= ext4_freeze,
1312 	.unfreeze_fs	= ext4_unfreeze,
1313 	.statfs		= ext4_statfs,
1314 	.remount_fs	= ext4_remount,
1315 	.show_options	= ext4_show_options,
1316 #ifdef CONFIG_QUOTA
1317 	.quota_read	= ext4_quota_read,
1318 	.quota_write	= ext4_quota_write,
1319 	.get_dquots	= ext4_get_dquots,
1320 #endif
1321 	.bdev_try_to_free_page = bdev_try_to_free_page,
1322 };
1323 
1324 static const struct export_operations ext4_export_ops = {
1325 	.fh_to_dentry = ext4_fh_to_dentry,
1326 	.fh_to_parent = ext4_fh_to_parent,
1327 	.get_parent = ext4_get_parent,
1328 };
1329 
1330 enum {
1331 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1332 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1333 	Opt_nouid32, Opt_debug, Opt_removed,
1334 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1335 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1336 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1337 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1338 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1339 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1340 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1341 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1342 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1343 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1344 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1345 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1346 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1347 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1348 	Opt_dioread_nolock, Opt_dioread_lock,
1349 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1350 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
1351 };
1352 
1353 static const match_table_t tokens = {
1354 	{Opt_bsd_df, "bsddf"},
1355 	{Opt_minix_df, "minixdf"},
1356 	{Opt_grpid, "grpid"},
1357 	{Opt_grpid, "bsdgroups"},
1358 	{Opt_nogrpid, "nogrpid"},
1359 	{Opt_nogrpid, "sysvgroups"},
1360 	{Opt_resgid, "resgid=%u"},
1361 	{Opt_resuid, "resuid=%u"},
1362 	{Opt_sb, "sb=%u"},
1363 	{Opt_err_cont, "errors=continue"},
1364 	{Opt_err_panic, "errors=panic"},
1365 	{Opt_err_ro, "errors=remount-ro"},
1366 	{Opt_nouid32, "nouid32"},
1367 	{Opt_debug, "debug"},
1368 	{Opt_removed, "oldalloc"},
1369 	{Opt_removed, "orlov"},
1370 	{Opt_user_xattr, "user_xattr"},
1371 	{Opt_nouser_xattr, "nouser_xattr"},
1372 	{Opt_acl, "acl"},
1373 	{Opt_noacl, "noacl"},
1374 	{Opt_noload, "norecovery"},
1375 	{Opt_noload, "noload"},
1376 	{Opt_removed, "nobh"},
1377 	{Opt_removed, "bh"},
1378 	{Opt_commit, "commit=%u"},
1379 	{Opt_min_batch_time, "min_batch_time=%u"},
1380 	{Opt_max_batch_time, "max_batch_time=%u"},
1381 	{Opt_journal_dev, "journal_dev=%u"},
1382 	{Opt_journal_path, "journal_path=%s"},
1383 	{Opt_journal_checksum, "journal_checksum"},
1384 	{Opt_nojournal_checksum, "nojournal_checksum"},
1385 	{Opt_journal_async_commit, "journal_async_commit"},
1386 	{Opt_abort, "abort"},
1387 	{Opt_data_journal, "data=journal"},
1388 	{Opt_data_ordered, "data=ordered"},
1389 	{Opt_data_writeback, "data=writeback"},
1390 	{Opt_data_err_abort, "data_err=abort"},
1391 	{Opt_data_err_ignore, "data_err=ignore"},
1392 	{Opt_offusrjquota, "usrjquota="},
1393 	{Opt_usrjquota, "usrjquota=%s"},
1394 	{Opt_offgrpjquota, "grpjquota="},
1395 	{Opt_grpjquota, "grpjquota=%s"},
1396 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1397 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1398 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1399 	{Opt_grpquota, "grpquota"},
1400 	{Opt_noquota, "noquota"},
1401 	{Opt_quota, "quota"},
1402 	{Opt_usrquota, "usrquota"},
1403 	{Opt_prjquota, "prjquota"},
1404 	{Opt_barrier, "barrier=%u"},
1405 	{Opt_barrier, "barrier"},
1406 	{Opt_nobarrier, "nobarrier"},
1407 	{Opt_i_version, "i_version"},
1408 	{Opt_dax, "dax"},
1409 	{Opt_stripe, "stripe=%u"},
1410 	{Opt_delalloc, "delalloc"},
1411 	{Opt_lazytime, "lazytime"},
1412 	{Opt_nolazytime, "nolazytime"},
1413 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1414 	{Opt_nodelalloc, "nodelalloc"},
1415 	{Opt_removed, "mblk_io_submit"},
1416 	{Opt_removed, "nomblk_io_submit"},
1417 	{Opt_block_validity, "block_validity"},
1418 	{Opt_noblock_validity, "noblock_validity"},
1419 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1420 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1421 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1422 	{Opt_auto_da_alloc, "auto_da_alloc"},
1423 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1424 	{Opt_dioread_nolock, "dioread_nolock"},
1425 	{Opt_dioread_lock, "dioread_lock"},
1426 	{Opt_discard, "discard"},
1427 	{Opt_nodiscard, "nodiscard"},
1428 	{Opt_init_itable, "init_itable=%u"},
1429 	{Opt_init_itable, "init_itable"},
1430 	{Opt_noinit_itable, "noinit_itable"},
1431 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1432 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1433 	{Opt_nombcache, "nombcache"},
1434 	{Opt_nombcache, "no_mbcache"},	/* for backward compatibility */
1435 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1436 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1437 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1438 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1439 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1440 	{Opt_err, NULL},
1441 };
1442 
1443 static ext4_fsblk_t get_sb_block(void **data)
1444 {
1445 	ext4_fsblk_t	sb_block;
1446 	char		*options = (char *) *data;
1447 
1448 	if (!options || strncmp(options, "sb=", 3) != 0)
1449 		return 1;	/* Default location */
1450 
1451 	options += 3;
1452 	/* TODO: use simple_strtoll with >32bit ext4 */
1453 	sb_block = simple_strtoul(options, &options, 0);
1454 	if (*options && *options != ',') {
1455 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1456 		       (char *) *data);
1457 		return 1;
1458 	}
1459 	if (*options == ',')
1460 		options++;
1461 	*data = (void *) options;
1462 
1463 	return sb_block;
1464 }
1465 
1466 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1467 static const char deprecated_msg[] =
1468 	"Mount option \"%s\" will be removed by %s\n"
1469 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1470 
1471 #ifdef CONFIG_QUOTA
1472 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1473 {
1474 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1475 	char *qname;
1476 	int ret = -1;
1477 
1478 	if (sb_any_quota_loaded(sb) &&
1479 		!sbi->s_qf_names[qtype]) {
1480 		ext4_msg(sb, KERN_ERR,
1481 			"Cannot change journaled "
1482 			"quota options when quota turned on");
1483 		return -1;
1484 	}
1485 	if (ext4_has_feature_quota(sb)) {
1486 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1487 			 "ignored when QUOTA feature is enabled");
1488 		return 1;
1489 	}
1490 	qname = match_strdup(args);
1491 	if (!qname) {
1492 		ext4_msg(sb, KERN_ERR,
1493 			"Not enough memory for storing quotafile name");
1494 		return -1;
1495 	}
1496 	if (sbi->s_qf_names[qtype]) {
1497 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1498 			ret = 1;
1499 		else
1500 			ext4_msg(sb, KERN_ERR,
1501 				 "%s quota file already specified",
1502 				 QTYPE2NAME(qtype));
1503 		goto errout;
1504 	}
1505 	if (strchr(qname, '/')) {
1506 		ext4_msg(sb, KERN_ERR,
1507 			"quotafile must be on filesystem root");
1508 		goto errout;
1509 	}
1510 	sbi->s_qf_names[qtype] = qname;
1511 	set_opt(sb, QUOTA);
1512 	return 1;
1513 errout:
1514 	kfree(qname);
1515 	return ret;
1516 }
1517 
1518 static int clear_qf_name(struct super_block *sb, int qtype)
1519 {
1520 
1521 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1522 
1523 	if (sb_any_quota_loaded(sb) &&
1524 		sbi->s_qf_names[qtype]) {
1525 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1526 			" when quota turned on");
1527 		return -1;
1528 	}
1529 	kfree(sbi->s_qf_names[qtype]);
1530 	sbi->s_qf_names[qtype] = NULL;
1531 	return 1;
1532 }
1533 #endif
1534 
1535 #define MOPT_SET	0x0001
1536 #define MOPT_CLEAR	0x0002
1537 #define MOPT_NOSUPPORT	0x0004
1538 #define MOPT_EXPLICIT	0x0008
1539 #define MOPT_CLEAR_ERR	0x0010
1540 #define MOPT_GTE0	0x0020
1541 #ifdef CONFIG_QUOTA
1542 #define MOPT_Q		0
1543 #define MOPT_QFMT	0x0040
1544 #else
1545 #define MOPT_Q		MOPT_NOSUPPORT
1546 #define MOPT_QFMT	MOPT_NOSUPPORT
1547 #endif
1548 #define MOPT_DATAJ	0x0080
1549 #define MOPT_NO_EXT2	0x0100
1550 #define MOPT_NO_EXT3	0x0200
1551 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1552 #define MOPT_STRING	0x0400
1553 
1554 static const struct mount_opts {
1555 	int	token;
1556 	int	mount_opt;
1557 	int	flags;
1558 } ext4_mount_opts[] = {
1559 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1560 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1561 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1562 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1563 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1564 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1565 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1566 	 MOPT_EXT4_ONLY | MOPT_SET},
1567 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1568 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1569 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1570 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1571 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1572 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1573 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1574 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1575 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1576 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1577 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1578 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1579 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1580 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1581 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1582 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1583 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1584 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1585 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1586 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1587 	 MOPT_NO_EXT2},
1588 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1589 	 MOPT_NO_EXT2},
1590 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1591 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1592 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1593 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1594 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1595 	{Opt_commit, 0, MOPT_GTE0},
1596 	{Opt_max_batch_time, 0, MOPT_GTE0},
1597 	{Opt_min_batch_time, 0, MOPT_GTE0},
1598 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1599 	{Opt_init_itable, 0, MOPT_GTE0},
1600 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1601 	{Opt_stripe, 0, MOPT_GTE0},
1602 	{Opt_resuid, 0, MOPT_GTE0},
1603 	{Opt_resgid, 0, MOPT_GTE0},
1604 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1605 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1606 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1607 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1608 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1609 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1610 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1611 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1612 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1613 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1614 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1615 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1616 #else
1617 	{Opt_acl, 0, MOPT_NOSUPPORT},
1618 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1619 #endif
1620 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1621 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1622 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1623 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1624 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1625 							MOPT_SET | MOPT_Q},
1626 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1627 							MOPT_SET | MOPT_Q},
1628 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1629 							MOPT_SET | MOPT_Q},
1630 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1631 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1632 							MOPT_CLEAR | MOPT_Q},
1633 	{Opt_usrjquota, 0, MOPT_Q},
1634 	{Opt_grpjquota, 0, MOPT_Q},
1635 	{Opt_offusrjquota, 0, MOPT_Q},
1636 	{Opt_offgrpjquota, 0, MOPT_Q},
1637 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1638 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1639 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1640 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1641 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1642 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
1643 	{Opt_err, 0, 0}
1644 };
1645 
1646 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1647 			    substring_t *args, unsigned long *journal_devnum,
1648 			    unsigned int *journal_ioprio, int is_remount)
1649 {
1650 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1651 	const struct mount_opts *m;
1652 	kuid_t uid;
1653 	kgid_t gid;
1654 	int arg = 0;
1655 
1656 #ifdef CONFIG_QUOTA
1657 	if (token == Opt_usrjquota)
1658 		return set_qf_name(sb, USRQUOTA, &args[0]);
1659 	else if (token == Opt_grpjquota)
1660 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1661 	else if (token == Opt_offusrjquota)
1662 		return clear_qf_name(sb, USRQUOTA);
1663 	else if (token == Opt_offgrpjquota)
1664 		return clear_qf_name(sb, GRPQUOTA);
1665 #endif
1666 	switch (token) {
1667 	case Opt_noacl:
1668 	case Opt_nouser_xattr:
1669 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1670 		break;
1671 	case Opt_sb:
1672 		return 1;	/* handled by get_sb_block() */
1673 	case Opt_removed:
1674 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1675 		return 1;
1676 	case Opt_abort:
1677 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1678 		return 1;
1679 	case Opt_i_version:
1680 		sb->s_flags |= MS_I_VERSION;
1681 		return 1;
1682 	case Opt_lazytime:
1683 		sb->s_flags |= MS_LAZYTIME;
1684 		return 1;
1685 	case Opt_nolazytime:
1686 		sb->s_flags &= ~MS_LAZYTIME;
1687 		return 1;
1688 	}
1689 
1690 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1691 		if (token == m->token)
1692 			break;
1693 
1694 	if (m->token == Opt_err) {
1695 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1696 			 "or missing value", opt);
1697 		return -1;
1698 	}
1699 
1700 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1701 		ext4_msg(sb, KERN_ERR,
1702 			 "Mount option \"%s\" incompatible with ext2", opt);
1703 		return -1;
1704 	}
1705 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1706 		ext4_msg(sb, KERN_ERR,
1707 			 "Mount option \"%s\" incompatible with ext3", opt);
1708 		return -1;
1709 	}
1710 
1711 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1712 		return -1;
1713 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1714 		return -1;
1715 	if (m->flags & MOPT_EXPLICIT) {
1716 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1717 			set_opt2(sb, EXPLICIT_DELALLOC);
1718 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1719 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1720 		} else
1721 			return -1;
1722 	}
1723 	if (m->flags & MOPT_CLEAR_ERR)
1724 		clear_opt(sb, ERRORS_MASK);
1725 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1726 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1727 			 "options when quota turned on");
1728 		return -1;
1729 	}
1730 
1731 	if (m->flags & MOPT_NOSUPPORT) {
1732 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1733 	} else if (token == Opt_commit) {
1734 		if (arg == 0)
1735 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1736 		sbi->s_commit_interval = HZ * arg;
1737 	} else if (token == Opt_debug_want_extra_isize) {
1738 		sbi->s_want_extra_isize = arg;
1739 	} else if (token == Opt_max_batch_time) {
1740 		sbi->s_max_batch_time = arg;
1741 	} else if (token == Opt_min_batch_time) {
1742 		sbi->s_min_batch_time = arg;
1743 	} else if (token == Opt_inode_readahead_blks) {
1744 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1745 			ext4_msg(sb, KERN_ERR,
1746 				 "EXT4-fs: inode_readahead_blks must be "
1747 				 "0 or a power of 2 smaller than 2^31");
1748 			return -1;
1749 		}
1750 		sbi->s_inode_readahead_blks = arg;
1751 	} else if (token == Opt_init_itable) {
1752 		set_opt(sb, INIT_INODE_TABLE);
1753 		if (!args->from)
1754 			arg = EXT4_DEF_LI_WAIT_MULT;
1755 		sbi->s_li_wait_mult = arg;
1756 	} else if (token == Opt_max_dir_size_kb) {
1757 		sbi->s_max_dir_size_kb = arg;
1758 	} else if (token == Opt_stripe) {
1759 		sbi->s_stripe = arg;
1760 	} else if (token == Opt_resuid) {
1761 		uid = make_kuid(current_user_ns(), arg);
1762 		if (!uid_valid(uid)) {
1763 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1764 			return -1;
1765 		}
1766 		sbi->s_resuid = uid;
1767 	} else if (token == Opt_resgid) {
1768 		gid = make_kgid(current_user_ns(), arg);
1769 		if (!gid_valid(gid)) {
1770 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1771 			return -1;
1772 		}
1773 		sbi->s_resgid = gid;
1774 	} else if (token == Opt_journal_dev) {
1775 		if (is_remount) {
1776 			ext4_msg(sb, KERN_ERR,
1777 				 "Cannot specify journal on remount");
1778 			return -1;
1779 		}
1780 		*journal_devnum = arg;
1781 	} else if (token == Opt_journal_path) {
1782 		char *journal_path;
1783 		struct inode *journal_inode;
1784 		struct path path;
1785 		int error;
1786 
1787 		if (is_remount) {
1788 			ext4_msg(sb, KERN_ERR,
1789 				 "Cannot specify journal on remount");
1790 			return -1;
1791 		}
1792 		journal_path = match_strdup(&args[0]);
1793 		if (!journal_path) {
1794 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1795 				"journal device string");
1796 			return -1;
1797 		}
1798 
1799 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1800 		if (error) {
1801 			ext4_msg(sb, KERN_ERR, "error: could not find "
1802 				"journal device path: error %d", error);
1803 			kfree(journal_path);
1804 			return -1;
1805 		}
1806 
1807 		journal_inode = d_inode(path.dentry);
1808 		if (!S_ISBLK(journal_inode->i_mode)) {
1809 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1810 				"is not a block device", journal_path);
1811 			path_put(&path);
1812 			kfree(journal_path);
1813 			return -1;
1814 		}
1815 
1816 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1817 		path_put(&path);
1818 		kfree(journal_path);
1819 	} else if (token == Opt_journal_ioprio) {
1820 		if (arg > 7) {
1821 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1822 				 " (must be 0-7)");
1823 			return -1;
1824 		}
1825 		*journal_ioprio =
1826 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1827 	} else if (token == Opt_test_dummy_encryption) {
1828 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1829 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1830 		ext4_msg(sb, KERN_WARNING,
1831 			 "Test dummy encryption mode enabled");
1832 #else
1833 		ext4_msg(sb, KERN_WARNING,
1834 			 "Test dummy encryption mount option ignored");
1835 #endif
1836 	} else if (m->flags & MOPT_DATAJ) {
1837 		if (is_remount) {
1838 			if (!sbi->s_journal)
1839 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1840 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1841 				ext4_msg(sb, KERN_ERR,
1842 					 "Cannot change data mode on remount");
1843 				return -1;
1844 			}
1845 		} else {
1846 			clear_opt(sb, DATA_FLAGS);
1847 			sbi->s_mount_opt |= m->mount_opt;
1848 		}
1849 #ifdef CONFIG_QUOTA
1850 	} else if (m->flags & MOPT_QFMT) {
1851 		if (sb_any_quota_loaded(sb) &&
1852 		    sbi->s_jquota_fmt != m->mount_opt) {
1853 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1854 				 "quota options when quota turned on");
1855 			return -1;
1856 		}
1857 		if (ext4_has_feature_quota(sb)) {
1858 			ext4_msg(sb, KERN_INFO,
1859 				 "Quota format mount options ignored "
1860 				 "when QUOTA feature is enabled");
1861 			return 1;
1862 		}
1863 		sbi->s_jquota_fmt = m->mount_opt;
1864 #endif
1865 	} else if (token == Opt_dax) {
1866 #ifdef CONFIG_FS_DAX
1867 		ext4_msg(sb, KERN_WARNING,
1868 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1869 			sbi->s_mount_opt |= m->mount_opt;
1870 #else
1871 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1872 		return -1;
1873 #endif
1874 	} else if (token == Opt_data_err_abort) {
1875 		sbi->s_mount_opt |= m->mount_opt;
1876 	} else if (token == Opt_data_err_ignore) {
1877 		sbi->s_mount_opt &= ~m->mount_opt;
1878 	} else {
1879 		if (!args->from)
1880 			arg = 1;
1881 		if (m->flags & MOPT_CLEAR)
1882 			arg = !arg;
1883 		else if (unlikely(!(m->flags & MOPT_SET))) {
1884 			ext4_msg(sb, KERN_WARNING,
1885 				 "buggy handling of option %s", opt);
1886 			WARN_ON(1);
1887 			return -1;
1888 		}
1889 		if (arg != 0)
1890 			sbi->s_mount_opt |= m->mount_opt;
1891 		else
1892 			sbi->s_mount_opt &= ~m->mount_opt;
1893 	}
1894 	return 1;
1895 }
1896 
1897 static int parse_options(char *options, struct super_block *sb,
1898 			 unsigned long *journal_devnum,
1899 			 unsigned int *journal_ioprio,
1900 			 int is_remount)
1901 {
1902 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1903 	char *p;
1904 	substring_t args[MAX_OPT_ARGS];
1905 	int token;
1906 
1907 	if (!options)
1908 		return 1;
1909 
1910 	while ((p = strsep(&options, ",")) != NULL) {
1911 		if (!*p)
1912 			continue;
1913 		/*
1914 		 * Initialize args struct so we know whether arg was
1915 		 * found; some options take optional arguments.
1916 		 */
1917 		args[0].to = args[0].from = NULL;
1918 		token = match_token(p, tokens, args);
1919 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1920 				     journal_ioprio, is_remount) < 0)
1921 			return 0;
1922 	}
1923 #ifdef CONFIG_QUOTA
1924 	/*
1925 	 * We do the test below only for project quotas. 'usrquota' and
1926 	 * 'grpquota' mount options are allowed even without quota feature
1927 	 * to support legacy quotas in quota files.
1928 	 */
1929 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1930 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1931 			 "Cannot enable project quota enforcement.");
1932 		return 0;
1933 	}
1934 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1935 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1936 			clear_opt(sb, USRQUOTA);
1937 
1938 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1939 			clear_opt(sb, GRPQUOTA);
1940 
1941 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1942 			ext4_msg(sb, KERN_ERR, "old and new quota "
1943 					"format mixing");
1944 			return 0;
1945 		}
1946 
1947 		if (!sbi->s_jquota_fmt) {
1948 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1949 					"not specified");
1950 			return 0;
1951 		}
1952 	}
1953 #endif
1954 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1955 		int blocksize =
1956 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1957 
1958 		if (blocksize < PAGE_SIZE) {
1959 			ext4_msg(sb, KERN_ERR, "can't mount with "
1960 				 "dioread_nolock if block size != PAGE_SIZE");
1961 			return 0;
1962 		}
1963 	}
1964 	return 1;
1965 }
1966 
1967 static inline void ext4_show_quota_options(struct seq_file *seq,
1968 					   struct super_block *sb)
1969 {
1970 #if defined(CONFIG_QUOTA)
1971 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1972 
1973 	if (sbi->s_jquota_fmt) {
1974 		char *fmtname = "";
1975 
1976 		switch (sbi->s_jquota_fmt) {
1977 		case QFMT_VFS_OLD:
1978 			fmtname = "vfsold";
1979 			break;
1980 		case QFMT_VFS_V0:
1981 			fmtname = "vfsv0";
1982 			break;
1983 		case QFMT_VFS_V1:
1984 			fmtname = "vfsv1";
1985 			break;
1986 		}
1987 		seq_printf(seq, ",jqfmt=%s", fmtname);
1988 	}
1989 
1990 	if (sbi->s_qf_names[USRQUOTA])
1991 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1992 
1993 	if (sbi->s_qf_names[GRPQUOTA])
1994 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1995 #endif
1996 }
1997 
1998 static const char *token2str(int token)
1999 {
2000 	const struct match_token *t;
2001 
2002 	for (t = tokens; t->token != Opt_err; t++)
2003 		if (t->token == token && !strchr(t->pattern, '='))
2004 			break;
2005 	return t->pattern;
2006 }
2007 
2008 /*
2009  * Show an option if
2010  *  - it's set to a non-default value OR
2011  *  - if the per-sb default is different from the global default
2012  */
2013 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
2014 			      int nodefs)
2015 {
2016 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2017 	struct ext4_super_block *es = sbi->s_es;
2018 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
2019 	const struct mount_opts *m;
2020 	char sep = nodefs ? '\n' : ',';
2021 
2022 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2023 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2024 
2025 	if (sbi->s_sb_block != 1)
2026 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2027 
2028 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2029 		int want_set = m->flags & MOPT_SET;
2030 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2031 		    (m->flags & MOPT_CLEAR_ERR))
2032 			continue;
2033 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2034 			continue; /* skip if same as the default */
2035 		if ((want_set &&
2036 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2037 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2038 			continue; /* select Opt_noFoo vs Opt_Foo */
2039 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2040 	}
2041 
2042 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2043 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2044 		SEQ_OPTS_PRINT("resuid=%u",
2045 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2046 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2047 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2048 		SEQ_OPTS_PRINT("resgid=%u",
2049 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2050 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2051 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2052 		SEQ_OPTS_PUTS("errors=remount-ro");
2053 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2054 		SEQ_OPTS_PUTS("errors=continue");
2055 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2056 		SEQ_OPTS_PUTS("errors=panic");
2057 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2058 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2059 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2060 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2061 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2062 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2063 	if (sb->s_flags & MS_I_VERSION)
2064 		SEQ_OPTS_PUTS("i_version");
2065 	if (nodefs || sbi->s_stripe)
2066 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2067 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2068 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2069 			SEQ_OPTS_PUTS("data=journal");
2070 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2071 			SEQ_OPTS_PUTS("data=ordered");
2072 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2073 			SEQ_OPTS_PUTS("data=writeback");
2074 	}
2075 	if (nodefs ||
2076 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2077 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2078 			       sbi->s_inode_readahead_blks);
2079 
2080 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2081 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2082 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2083 	if (nodefs || sbi->s_max_dir_size_kb)
2084 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2085 	if (test_opt(sb, DATA_ERR_ABORT))
2086 		SEQ_OPTS_PUTS("data_err=abort");
2087 
2088 	ext4_show_quota_options(seq, sb);
2089 	return 0;
2090 }
2091 
2092 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2093 {
2094 	return _ext4_show_options(seq, root->d_sb, 0);
2095 }
2096 
2097 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2098 {
2099 	struct super_block *sb = seq->private;
2100 	int rc;
2101 
2102 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2103 	rc = _ext4_show_options(seq, sb, 1);
2104 	seq_puts(seq, "\n");
2105 	return rc;
2106 }
2107 
2108 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2109 			    int read_only)
2110 {
2111 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2112 	int res = 0;
2113 
2114 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2115 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2116 			 "forcing read-only mode");
2117 		res = MS_RDONLY;
2118 	}
2119 	if (read_only)
2120 		goto done;
2121 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2122 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2123 			 "running e2fsck is recommended");
2124 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2125 		ext4_msg(sb, KERN_WARNING,
2126 			 "warning: mounting fs with errors, "
2127 			 "running e2fsck is recommended");
2128 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2129 		 le16_to_cpu(es->s_mnt_count) >=
2130 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2131 		ext4_msg(sb, KERN_WARNING,
2132 			 "warning: maximal mount count reached, "
2133 			 "running e2fsck is recommended");
2134 	else if (le32_to_cpu(es->s_checkinterval) &&
2135 		(le32_to_cpu(es->s_lastcheck) +
2136 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2137 		ext4_msg(sb, KERN_WARNING,
2138 			 "warning: checktime reached, "
2139 			 "running e2fsck is recommended");
2140 	if (!sbi->s_journal)
2141 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2142 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2143 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2144 	le16_add_cpu(&es->s_mnt_count, 1);
2145 	es->s_mtime = cpu_to_le32(get_seconds());
2146 	ext4_update_dynamic_rev(sb);
2147 	if (sbi->s_journal)
2148 		ext4_set_feature_journal_needs_recovery(sb);
2149 
2150 	ext4_commit_super(sb, 1);
2151 done:
2152 	if (test_opt(sb, DEBUG))
2153 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2154 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2155 			sb->s_blocksize,
2156 			sbi->s_groups_count,
2157 			EXT4_BLOCKS_PER_GROUP(sb),
2158 			EXT4_INODES_PER_GROUP(sb),
2159 			sbi->s_mount_opt, sbi->s_mount_opt2);
2160 
2161 	cleancache_init_fs(sb);
2162 	return res;
2163 }
2164 
2165 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2166 {
2167 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2168 	struct flex_groups *new_groups;
2169 	int size;
2170 
2171 	if (!sbi->s_log_groups_per_flex)
2172 		return 0;
2173 
2174 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2175 	if (size <= sbi->s_flex_groups_allocated)
2176 		return 0;
2177 
2178 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2179 	new_groups = kvzalloc(size, GFP_KERNEL);
2180 	if (!new_groups) {
2181 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2182 			 size / (int) sizeof(struct flex_groups));
2183 		return -ENOMEM;
2184 	}
2185 
2186 	if (sbi->s_flex_groups) {
2187 		memcpy(new_groups, sbi->s_flex_groups,
2188 		       (sbi->s_flex_groups_allocated *
2189 			sizeof(struct flex_groups)));
2190 		kvfree(sbi->s_flex_groups);
2191 	}
2192 	sbi->s_flex_groups = new_groups;
2193 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2194 	return 0;
2195 }
2196 
2197 static int ext4_fill_flex_info(struct super_block *sb)
2198 {
2199 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2200 	struct ext4_group_desc *gdp = NULL;
2201 	ext4_group_t flex_group;
2202 	int i, err;
2203 
2204 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2205 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2206 		sbi->s_log_groups_per_flex = 0;
2207 		return 1;
2208 	}
2209 
2210 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2211 	if (err)
2212 		goto failed;
2213 
2214 	for (i = 0; i < sbi->s_groups_count; i++) {
2215 		gdp = ext4_get_group_desc(sb, i, NULL);
2216 
2217 		flex_group = ext4_flex_group(sbi, i);
2218 		atomic_add(ext4_free_inodes_count(sb, gdp),
2219 			   &sbi->s_flex_groups[flex_group].free_inodes);
2220 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2221 			     &sbi->s_flex_groups[flex_group].free_clusters);
2222 		atomic_add(ext4_used_dirs_count(sb, gdp),
2223 			   &sbi->s_flex_groups[flex_group].used_dirs);
2224 	}
2225 
2226 	return 1;
2227 failed:
2228 	return 0;
2229 }
2230 
2231 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2232 				   struct ext4_group_desc *gdp)
2233 {
2234 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2235 	__u16 crc = 0;
2236 	__le32 le_group = cpu_to_le32(block_group);
2237 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2238 
2239 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2240 		/* Use new metadata_csum algorithm */
2241 		__u32 csum32;
2242 		__u16 dummy_csum = 0;
2243 
2244 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2245 				     sizeof(le_group));
2246 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2247 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2248 				     sizeof(dummy_csum));
2249 		offset += sizeof(dummy_csum);
2250 		if (offset < sbi->s_desc_size)
2251 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2252 					     sbi->s_desc_size - offset);
2253 
2254 		crc = csum32 & 0xFFFF;
2255 		goto out;
2256 	}
2257 
2258 	/* old crc16 code */
2259 	if (!ext4_has_feature_gdt_csum(sb))
2260 		return 0;
2261 
2262 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2263 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2264 	crc = crc16(crc, (__u8 *)gdp, offset);
2265 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2266 	/* for checksum of struct ext4_group_desc do the rest...*/
2267 	if (ext4_has_feature_64bit(sb) &&
2268 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2269 		crc = crc16(crc, (__u8 *)gdp + offset,
2270 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2271 				offset);
2272 
2273 out:
2274 	return cpu_to_le16(crc);
2275 }
2276 
2277 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2278 				struct ext4_group_desc *gdp)
2279 {
2280 	if (ext4_has_group_desc_csum(sb) &&
2281 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2282 		return 0;
2283 
2284 	return 1;
2285 }
2286 
2287 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2288 			      struct ext4_group_desc *gdp)
2289 {
2290 	if (!ext4_has_group_desc_csum(sb))
2291 		return;
2292 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2293 }
2294 
2295 /* Called at mount-time, super-block is locked */
2296 static int ext4_check_descriptors(struct super_block *sb,
2297 				  ext4_fsblk_t sb_block,
2298 				  ext4_group_t *first_not_zeroed)
2299 {
2300 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2301 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2302 	ext4_fsblk_t last_block;
2303 	ext4_fsblk_t block_bitmap;
2304 	ext4_fsblk_t inode_bitmap;
2305 	ext4_fsblk_t inode_table;
2306 	int flexbg_flag = 0;
2307 	ext4_group_t i, grp = sbi->s_groups_count;
2308 
2309 	if (ext4_has_feature_flex_bg(sb))
2310 		flexbg_flag = 1;
2311 
2312 	ext4_debug("Checking group descriptors");
2313 
2314 	for (i = 0; i < sbi->s_groups_count; i++) {
2315 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2316 
2317 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2318 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2319 		else
2320 			last_block = first_block +
2321 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2322 
2323 		if ((grp == sbi->s_groups_count) &&
2324 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2325 			grp = i;
2326 
2327 		block_bitmap = ext4_block_bitmap(sb, gdp);
2328 		if (block_bitmap == sb_block) {
2329 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2330 				 "Block bitmap for group %u overlaps "
2331 				 "superblock", i);
2332 		}
2333 		if (block_bitmap < first_block || block_bitmap > last_block) {
2334 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2335 			       "Block bitmap for group %u not in group "
2336 			       "(block %llu)!", i, block_bitmap);
2337 			return 0;
2338 		}
2339 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2340 		if (inode_bitmap == sb_block) {
2341 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2342 				 "Inode bitmap for group %u overlaps "
2343 				 "superblock", i);
2344 		}
2345 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2346 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2347 			       "Inode bitmap for group %u not in group "
2348 			       "(block %llu)!", i, inode_bitmap);
2349 			return 0;
2350 		}
2351 		inode_table = ext4_inode_table(sb, gdp);
2352 		if (inode_table == sb_block) {
2353 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2354 				 "Inode table for group %u overlaps "
2355 				 "superblock", i);
2356 		}
2357 		if (inode_table < first_block ||
2358 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2359 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2360 			       "Inode table for group %u not in group "
2361 			       "(block %llu)!", i, inode_table);
2362 			return 0;
2363 		}
2364 		ext4_lock_group(sb, i);
2365 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2366 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2367 				 "Checksum for group %u failed (%u!=%u)",
2368 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2369 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2370 			if (!(sb->s_flags & MS_RDONLY)) {
2371 				ext4_unlock_group(sb, i);
2372 				return 0;
2373 			}
2374 		}
2375 		ext4_unlock_group(sb, i);
2376 		if (!flexbg_flag)
2377 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2378 	}
2379 	if (NULL != first_not_zeroed)
2380 		*first_not_zeroed = grp;
2381 	return 1;
2382 }
2383 
2384 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2385  * the superblock) which were deleted from all directories, but held open by
2386  * a process at the time of a crash.  We walk the list and try to delete these
2387  * inodes at recovery time (only with a read-write filesystem).
2388  *
2389  * In order to keep the orphan inode chain consistent during traversal (in
2390  * case of crash during recovery), we link each inode into the superblock
2391  * orphan list_head and handle it the same way as an inode deletion during
2392  * normal operation (which journals the operations for us).
2393  *
2394  * We only do an iget() and an iput() on each inode, which is very safe if we
2395  * accidentally point at an in-use or already deleted inode.  The worst that
2396  * can happen in this case is that we get a "bit already cleared" message from
2397  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2398  * e2fsck was run on this filesystem, and it must have already done the orphan
2399  * inode cleanup for us, so we can safely abort without any further action.
2400  */
2401 static void ext4_orphan_cleanup(struct super_block *sb,
2402 				struct ext4_super_block *es)
2403 {
2404 	unsigned int s_flags = sb->s_flags;
2405 	int ret, nr_orphans = 0, nr_truncates = 0;
2406 #ifdef CONFIG_QUOTA
2407 	int quota_update = 0;
2408 	int i;
2409 #endif
2410 	if (!es->s_last_orphan) {
2411 		jbd_debug(4, "no orphan inodes to clean up\n");
2412 		return;
2413 	}
2414 
2415 	if (bdev_read_only(sb->s_bdev)) {
2416 		ext4_msg(sb, KERN_ERR, "write access "
2417 			"unavailable, skipping orphan cleanup");
2418 		return;
2419 	}
2420 
2421 	/* Check if feature set would not allow a r/w mount */
2422 	if (!ext4_feature_set_ok(sb, 0)) {
2423 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2424 			 "unknown ROCOMPAT features");
2425 		return;
2426 	}
2427 
2428 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2429 		/* don't clear list on RO mount w/ errors */
2430 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2431 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2432 				  "clearing orphan list.\n");
2433 			es->s_last_orphan = 0;
2434 		}
2435 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2436 		return;
2437 	}
2438 
2439 	if (s_flags & MS_RDONLY) {
2440 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2441 		sb->s_flags &= ~MS_RDONLY;
2442 	}
2443 #ifdef CONFIG_QUOTA
2444 	/* Needed for iput() to work correctly and not trash data */
2445 	sb->s_flags |= MS_ACTIVE;
2446 
2447 	/*
2448 	 * Turn on quotas which were not enabled for read-only mounts if
2449 	 * filesystem has quota feature, so that they are updated correctly.
2450 	 */
2451 	if (ext4_has_feature_quota(sb) && (s_flags & MS_RDONLY)) {
2452 		int ret = ext4_enable_quotas(sb);
2453 
2454 		if (!ret)
2455 			quota_update = 1;
2456 		else
2457 			ext4_msg(sb, KERN_ERR,
2458 				"Cannot turn on quotas: error %d", ret);
2459 	}
2460 
2461 	/* Turn on journaled quotas used for old sytle */
2462 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2463 		if (EXT4_SB(sb)->s_qf_names[i]) {
2464 			int ret = ext4_quota_on_mount(sb, i);
2465 
2466 			if (!ret)
2467 				quota_update = 1;
2468 			else
2469 				ext4_msg(sb, KERN_ERR,
2470 					"Cannot turn on journaled "
2471 					"quota: type %d: error %d", i, ret);
2472 		}
2473 	}
2474 #endif
2475 
2476 	while (es->s_last_orphan) {
2477 		struct inode *inode;
2478 
2479 		/*
2480 		 * We may have encountered an error during cleanup; if
2481 		 * so, skip the rest.
2482 		 */
2483 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2484 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2485 			es->s_last_orphan = 0;
2486 			break;
2487 		}
2488 
2489 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2490 		if (IS_ERR(inode)) {
2491 			es->s_last_orphan = 0;
2492 			break;
2493 		}
2494 
2495 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2496 		dquot_initialize(inode);
2497 		if (inode->i_nlink) {
2498 			if (test_opt(sb, DEBUG))
2499 				ext4_msg(sb, KERN_DEBUG,
2500 					"%s: truncating inode %lu to %lld bytes",
2501 					__func__, inode->i_ino, inode->i_size);
2502 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2503 				  inode->i_ino, inode->i_size);
2504 			inode_lock(inode);
2505 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2506 			ret = ext4_truncate(inode);
2507 			if (ret)
2508 				ext4_std_error(inode->i_sb, ret);
2509 			inode_unlock(inode);
2510 			nr_truncates++;
2511 		} else {
2512 			if (test_opt(sb, DEBUG))
2513 				ext4_msg(sb, KERN_DEBUG,
2514 					"%s: deleting unreferenced inode %lu",
2515 					__func__, inode->i_ino);
2516 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2517 				  inode->i_ino);
2518 			nr_orphans++;
2519 		}
2520 		iput(inode);  /* The delete magic happens here! */
2521 	}
2522 
2523 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2524 
2525 	if (nr_orphans)
2526 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2527 		       PLURAL(nr_orphans));
2528 	if (nr_truncates)
2529 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2530 		       PLURAL(nr_truncates));
2531 #ifdef CONFIG_QUOTA
2532 	/* Turn off quotas if they were enabled for orphan cleanup */
2533 	if (quota_update) {
2534 		for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2535 			if (sb_dqopt(sb)->files[i])
2536 				dquot_quota_off(sb, i);
2537 		}
2538 	}
2539 #endif
2540 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2541 }
2542 
2543 /*
2544  * Maximal extent format file size.
2545  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2546  * extent format containers, within a sector_t, and within i_blocks
2547  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2548  * so that won't be a limiting factor.
2549  *
2550  * However there is other limiting factor. We do store extents in the form
2551  * of starting block and length, hence the resulting length of the extent
2552  * covering maximum file size must fit into on-disk format containers as
2553  * well. Given that length is always by 1 unit bigger than max unit (because
2554  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2555  *
2556  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2557  */
2558 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2559 {
2560 	loff_t res;
2561 	loff_t upper_limit = MAX_LFS_FILESIZE;
2562 
2563 	/* small i_blocks in vfs inode? */
2564 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2565 		/*
2566 		 * CONFIG_LBDAF is not enabled implies the inode
2567 		 * i_block represent total blocks in 512 bytes
2568 		 * 32 == size of vfs inode i_blocks * 8
2569 		 */
2570 		upper_limit = (1LL << 32) - 1;
2571 
2572 		/* total blocks in file system block size */
2573 		upper_limit >>= (blkbits - 9);
2574 		upper_limit <<= blkbits;
2575 	}
2576 
2577 	/*
2578 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2579 	 * by one fs block, so ee_len can cover the extent of maximum file
2580 	 * size
2581 	 */
2582 	res = (1LL << 32) - 1;
2583 	res <<= blkbits;
2584 
2585 	/* Sanity check against vm- & vfs- imposed limits */
2586 	if (res > upper_limit)
2587 		res = upper_limit;
2588 
2589 	return res;
2590 }
2591 
2592 /*
2593  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2594  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2595  * We need to be 1 filesystem block less than the 2^48 sector limit.
2596  */
2597 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2598 {
2599 	loff_t res = EXT4_NDIR_BLOCKS;
2600 	int meta_blocks;
2601 	loff_t upper_limit;
2602 	/* This is calculated to be the largest file size for a dense, block
2603 	 * mapped file such that the file's total number of 512-byte sectors,
2604 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2605 	 *
2606 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2607 	 * number of 512-byte sectors of the file.
2608 	 */
2609 
2610 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2611 		/*
2612 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2613 		 * the inode i_block field represents total file blocks in
2614 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2615 		 */
2616 		upper_limit = (1LL << 32) - 1;
2617 
2618 		/* total blocks in file system block size */
2619 		upper_limit >>= (bits - 9);
2620 
2621 	} else {
2622 		/*
2623 		 * We use 48 bit ext4_inode i_blocks
2624 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2625 		 * represent total number of blocks in
2626 		 * file system block size
2627 		 */
2628 		upper_limit = (1LL << 48) - 1;
2629 
2630 	}
2631 
2632 	/* indirect blocks */
2633 	meta_blocks = 1;
2634 	/* double indirect blocks */
2635 	meta_blocks += 1 + (1LL << (bits-2));
2636 	/* tripple indirect blocks */
2637 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2638 
2639 	upper_limit -= meta_blocks;
2640 	upper_limit <<= bits;
2641 
2642 	res += 1LL << (bits-2);
2643 	res += 1LL << (2*(bits-2));
2644 	res += 1LL << (3*(bits-2));
2645 	res <<= bits;
2646 	if (res > upper_limit)
2647 		res = upper_limit;
2648 
2649 	if (res > MAX_LFS_FILESIZE)
2650 		res = MAX_LFS_FILESIZE;
2651 
2652 	return res;
2653 }
2654 
2655 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2656 				   ext4_fsblk_t logical_sb_block, int nr)
2657 {
2658 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2659 	ext4_group_t bg, first_meta_bg;
2660 	int has_super = 0;
2661 
2662 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2663 
2664 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2665 		return logical_sb_block + nr + 1;
2666 	bg = sbi->s_desc_per_block * nr;
2667 	if (ext4_bg_has_super(sb, bg))
2668 		has_super = 1;
2669 
2670 	/*
2671 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2672 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2673 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2674 	 * compensate.
2675 	 */
2676 	if (sb->s_blocksize == 1024 && nr == 0 &&
2677 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2678 		has_super++;
2679 
2680 	return (has_super + ext4_group_first_block_no(sb, bg));
2681 }
2682 
2683 /**
2684  * ext4_get_stripe_size: Get the stripe size.
2685  * @sbi: In memory super block info
2686  *
2687  * If we have specified it via mount option, then
2688  * use the mount option value. If the value specified at mount time is
2689  * greater than the blocks per group use the super block value.
2690  * If the super block value is greater than blocks per group return 0.
2691  * Allocator needs it be less than blocks per group.
2692  *
2693  */
2694 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2695 {
2696 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2697 	unsigned long stripe_width =
2698 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2699 	int ret;
2700 
2701 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2702 		ret = sbi->s_stripe;
2703 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2704 		ret = stripe_width;
2705 	else if (stride && stride <= sbi->s_blocks_per_group)
2706 		ret = stride;
2707 	else
2708 		ret = 0;
2709 
2710 	/*
2711 	 * If the stripe width is 1, this makes no sense and
2712 	 * we set it to 0 to turn off stripe handling code.
2713 	 */
2714 	if (ret <= 1)
2715 		ret = 0;
2716 
2717 	return ret;
2718 }
2719 
2720 /*
2721  * Check whether this filesystem can be mounted based on
2722  * the features present and the RDONLY/RDWR mount requested.
2723  * Returns 1 if this filesystem can be mounted as requested,
2724  * 0 if it cannot be.
2725  */
2726 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2727 {
2728 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2729 		ext4_msg(sb, KERN_ERR,
2730 			"Couldn't mount because of "
2731 			"unsupported optional features (%x)",
2732 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2733 			~EXT4_FEATURE_INCOMPAT_SUPP));
2734 		return 0;
2735 	}
2736 
2737 	if (readonly)
2738 		return 1;
2739 
2740 	if (ext4_has_feature_readonly(sb)) {
2741 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2742 		sb->s_flags |= MS_RDONLY;
2743 		return 1;
2744 	}
2745 
2746 	/* Check that feature set is OK for a read-write mount */
2747 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2748 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2749 			 "unsupported optional features (%x)",
2750 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2751 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2752 		return 0;
2753 	}
2754 	/*
2755 	 * Large file size enabled file system can only be mounted
2756 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2757 	 */
2758 	if (ext4_has_feature_huge_file(sb)) {
2759 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2760 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2761 				 "cannot be mounted RDWR without "
2762 				 "CONFIG_LBDAF");
2763 			return 0;
2764 		}
2765 	}
2766 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2767 		ext4_msg(sb, KERN_ERR,
2768 			 "Can't support bigalloc feature without "
2769 			 "extents feature\n");
2770 		return 0;
2771 	}
2772 
2773 #ifndef CONFIG_QUOTA
2774 	if (ext4_has_feature_quota(sb) && !readonly) {
2775 		ext4_msg(sb, KERN_ERR,
2776 			 "Filesystem with quota feature cannot be mounted RDWR "
2777 			 "without CONFIG_QUOTA");
2778 		return 0;
2779 	}
2780 	if (ext4_has_feature_project(sb) && !readonly) {
2781 		ext4_msg(sb, KERN_ERR,
2782 			 "Filesystem with project quota feature cannot be mounted RDWR "
2783 			 "without CONFIG_QUOTA");
2784 		return 0;
2785 	}
2786 #endif  /* CONFIG_QUOTA */
2787 	return 1;
2788 }
2789 
2790 /*
2791  * This function is called once a day if we have errors logged
2792  * on the file system
2793  */
2794 static void print_daily_error_info(unsigned long arg)
2795 {
2796 	struct super_block *sb = (struct super_block *) arg;
2797 	struct ext4_sb_info *sbi;
2798 	struct ext4_super_block *es;
2799 
2800 	sbi = EXT4_SB(sb);
2801 	es = sbi->s_es;
2802 
2803 	if (es->s_error_count)
2804 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2805 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2806 			 le32_to_cpu(es->s_error_count));
2807 	if (es->s_first_error_time) {
2808 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2809 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2810 		       (int) sizeof(es->s_first_error_func),
2811 		       es->s_first_error_func,
2812 		       le32_to_cpu(es->s_first_error_line));
2813 		if (es->s_first_error_ino)
2814 			printk(KERN_CONT ": inode %u",
2815 			       le32_to_cpu(es->s_first_error_ino));
2816 		if (es->s_first_error_block)
2817 			printk(KERN_CONT ": block %llu", (unsigned long long)
2818 			       le64_to_cpu(es->s_first_error_block));
2819 		printk(KERN_CONT "\n");
2820 	}
2821 	if (es->s_last_error_time) {
2822 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2823 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2824 		       (int) sizeof(es->s_last_error_func),
2825 		       es->s_last_error_func,
2826 		       le32_to_cpu(es->s_last_error_line));
2827 		if (es->s_last_error_ino)
2828 			printk(KERN_CONT ": inode %u",
2829 			       le32_to_cpu(es->s_last_error_ino));
2830 		if (es->s_last_error_block)
2831 			printk(KERN_CONT ": block %llu", (unsigned long long)
2832 			       le64_to_cpu(es->s_last_error_block));
2833 		printk(KERN_CONT "\n");
2834 	}
2835 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2836 }
2837 
2838 /* Find next suitable group and run ext4_init_inode_table */
2839 static int ext4_run_li_request(struct ext4_li_request *elr)
2840 {
2841 	struct ext4_group_desc *gdp = NULL;
2842 	ext4_group_t group, ngroups;
2843 	struct super_block *sb;
2844 	unsigned long timeout = 0;
2845 	int ret = 0;
2846 
2847 	sb = elr->lr_super;
2848 	ngroups = EXT4_SB(sb)->s_groups_count;
2849 
2850 	for (group = elr->lr_next_group; group < ngroups; group++) {
2851 		gdp = ext4_get_group_desc(sb, group, NULL);
2852 		if (!gdp) {
2853 			ret = 1;
2854 			break;
2855 		}
2856 
2857 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2858 			break;
2859 	}
2860 
2861 	if (group >= ngroups)
2862 		ret = 1;
2863 
2864 	if (!ret) {
2865 		timeout = jiffies;
2866 		ret = ext4_init_inode_table(sb, group,
2867 					    elr->lr_timeout ? 0 : 1);
2868 		if (elr->lr_timeout == 0) {
2869 			timeout = (jiffies - timeout) *
2870 				  elr->lr_sbi->s_li_wait_mult;
2871 			elr->lr_timeout = timeout;
2872 		}
2873 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2874 		elr->lr_next_group = group + 1;
2875 	}
2876 	return ret;
2877 }
2878 
2879 /*
2880  * Remove lr_request from the list_request and free the
2881  * request structure. Should be called with li_list_mtx held
2882  */
2883 static void ext4_remove_li_request(struct ext4_li_request *elr)
2884 {
2885 	struct ext4_sb_info *sbi;
2886 
2887 	if (!elr)
2888 		return;
2889 
2890 	sbi = elr->lr_sbi;
2891 
2892 	list_del(&elr->lr_request);
2893 	sbi->s_li_request = NULL;
2894 	kfree(elr);
2895 }
2896 
2897 static void ext4_unregister_li_request(struct super_block *sb)
2898 {
2899 	mutex_lock(&ext4_li_mtx);
2900 	if (!ext4_li_info) {
2901 		mutex_unlock(&ext4_li_mtx);
2902 		return;
2903 	}
2904 
2905 	mutex_lock(&ext4_li_info->li_list_mtx);
2906 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2907 	mutex_unlock(&ext4_li_info->li_list_mtx);
2908 	mutex_unlock(&ext4_li_mtx);
2909 }
2910 
2911 static struct task_struct *ext4_lazyinit_task;
2912 
2913 /*
2914  * This is the function where ext4lazyinit thread lives. It walks
2915  * through the request list searching for next scheduled filesystem.
2916  * When such a fs is found, run the lazy initialization request
2917  * (ext4_rn_li_request) and keep track of the time spend in this
2918  * function. Based on that time we compute next schedule time of
2919  * the request. When walking through the list is complete, compute
2920  * next waking time and put itself into sleep.
2921  */
2922 static int ext4_lazyinit_thread(void *arg)
2923 {
2924 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2925 	struct list_head *pos, *n;
2926 	struct ext4_li_request *elr;
2927 	unsigned long next_wakeup, cur;
2928 
2929 	BUG_ON(NULL == eli);
2930 
2931 cont_thread:
2932 	while (true) {
2933 		next_wakeup = MAX_JIFFY_OFFSET;
2934 
2935 		mutex_lock(&eli->li_list_mtx);
2936 		if (list_empty(&eli->li_request_list)) {
2937 			mutex_unlock(&eli->li_list_mtx);
2938 			goto exit_thread;
2939 		}
2940 		list_for_each_safe(pos, n, &eli->li_request_list) {
2941 			int err = 0;
2942 			int progress = 0;
2943 			elr = list_entry(pos, struct ext4_li_request,
2944 					 lr_request);
2945 
2946 			if (time_before(jiffies, elr->lr_next_sched)) {
2947 				if (time_before(elr->lr_next_sched, next_wakeup))
2948 					next_wakeup = elr->lr_next_sched;
2949 				continue;
2950 			}
2951 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2952 				if (sb_start_write_trylock(elr->lr_super)) {
2953 					progress = 1;
2954 					/*
2955 					 * We hold sb->s_umount, sb can not
2956 					 * be removed from the list, it is
2957 					 * now safe to drop li_list_mtx
2958 					 */
2959 					mutex_unlock(&eli->li_list_mtx);
2960 					err = ext4_run_li_request(elr);
2961 					sb_end_write(elr->lr_super);
2962 					mutex_lock(&eli->li_list_mtx);
2963 					n = pos->next;
2964 				}
2965 				up_read((&elr->lr_super->s_umount));
2966 			}
2967 			/* error, remove the lazy_init job */
2968 			if (err) {
2969 				ext4_remove_li_request(elr);
2970 				continue;
2971 			}
2972 			if (!progress) {
2973 				elr->lr_next_sched = jiffies +
2974 					(prandom_u32()
2975 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2976 			}
2977 			if (time_before(elr->lr_next_sched, next_wakeup))
2978 				next_wakeup = elr->lr_next_sched;
2979 		}
2980 		mutex_unlock(&eli->li_list_mtx);
2981 
2982 		try_to_freeze();
2983 
2984 		cur = jiffies;
2985 		if ((time_after_eq(cur, next_wakeup)) ||
2986 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2987 			cond_resched();
2988 			continue;
2989 		}
2990 
2991 		schedule_timeout_interruptible(next_wakeup - cur);
2992 
2993 		if (kthread_should_stop()) {
2994 			ext4_clear_request_list();
2995 			goto exit_thread;
2996 		}
2997 	}
2998 
2999 exit_thread:
3000 	/*
3001 	 * It looks like the request list is empty, but we need
3002 	 * to check it under the li_list_mtx lock, to prevent any
3003 	 * additions into it, and of course we should lock ext4_li_mtx
3004 	 * to atomically free the list and ext4_li_info, because at
3005 	 * this point another ext4 filesystem could be registering
3006 	 * new one.
3007 	 */
3008 	mutex_lock(&ext4_li_mtx);
3009 	mutex_lock(&eli->li_list_mtx);
3010 	if (!list_empty(&eli->li_request_list)) {
3011 		mutex_unlock(&eli->li_list_mtx);
3012 		mutex_unlock(&ext4_li_mtx);
3013 		goto cont_thread;
3014 	}
3015 	mutex_unlock(&eli->li_list_mtx);
3016 	kfree(ext4_li_info);
3017 	ext4_li_info = NULL;
3018 	mutex_unlock(&ext4_li_mtx);
3019 
3020 	return 0;
3021 }
3022 
3023 static void ext4_clear_request_list(void)
3024 {
3025 	struct list_head *pos, *n;
3026 	struct ext4_li_request *elr;
3027 
3028 	mutex_lock(&ext4_li_info->li_list_mtx);
3029 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
3030 		elr = list_entry(pos, struct ext4_li_request,
3031 				 lr_request);
3032 		ext4_remove_li_request(elr);
3033 	}
3034 	mutex_unlock(&ext4_li_info->li_list_mtx);
3035 }
3036 
3037 static int ext4_run_lazyinit_thread(void)
3038 {
3039 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
3040 					 ext4_li_info, "ext4lazyinit");
3041 	if (IS_ERR(ext4_lazyinit_task)) {
3042 		int err = PTR_ERR(ext4_lazyinit_task);
3043 		ext4_clear_request_list();
3044 		kfree(ext4_li_info);
3045 		ext4_li_info = NULL;
3046 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3047 				 "initialization thread\n",
3048 				 err);
3049 		return err;
3050 	}
3051 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3052 	return 0;
3053 }
3054 
3055 /*
3056  * Check whether it make sense to run itable init. thread or not.
3057  * If there is at least one uninitialized inode table, return
3058  * corresponding group number, else the loop goes through all
3059  * groups and return total number of groups.
3060  */
3061 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3062 {
3063 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3064 	struct ext4_group_desc *gdp = NULL;
3065 
3066 	for (group = 0; group < ngroups; group++) {
3067 		gdp = ext4_get_group_desc(sb, group, NULL);
3068 		if (!gdp)
3069 			continue;
3070 
3071 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3072 			break;
3073 	}
3074 
3075 	return group;
3076 }
3077 
3078 static int ext4_li_info_new(void)
3079 {
3080 	struct ext4_lazy_init *eli = NULL;
3081 
3082 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3083 	if (!eli)
3084 		return -ENOMEM;
3085 
3086 	INIT_LIST_HEAD(&eli->li_request_list);
3087 	mutex_init(&eli->li_list_mtx);
3088 
3089 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3090 
3091 	ext4_li_info = eli;
3092 
3093 	return 0;
3094 }
3095 
3096 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3097 					    ext4_group_t start)
3098 {
3099 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3100 	struct ext4_li_request *elr;
3101 
3102 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3103 	if (!elr)
3104 		return NULL;
3105 
3106 	elr->lr_super = sb;
3107 	elr->lr_sbi = sbi;
3108 	elr->lr_next_group = start;
3109 
3110 	/*
3111 	 * Randomize first schedule time of the request to
3112 	 * spread the inode table initialization requests
3113 	 * better.
3114 	 */
3115 	elr->lr_next_sched = jiffies + (prandom_u32() %
3116 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3117 	return elr;
3118 }
3119 
3120 int ext4_register_li_request(struct super_block *sb,
3121 			     ext4_group_t first_not_zeroed)
3122 {
3123 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3124 	struct ext4_li_request *elr = NULL;
3125 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3126 	int ret = 0;
3127 
3128 	mutex_lock(&ext4_li_mtx);
3129 	if (sbi->s_li_request != NULL) {
3130 		/*
3131 		 * Reset timeout so it can be computed again, because
3132 		 * s_li_wait_mult might have changed.
3133 		 */
3134 		sbi->s_li_request->lr_timeout = 0;
3135 		goto out;
3136 	}
3137 
3138 	if (first_not_zeroed == ngroups ||
3139 	    (sb->s_flags & MS_RDONLY) ||
3140 	    !test_opt(sb, INIT_INODE_TABLE))
3141 		goto out;
3142 
3143 	elr = ext4_li_request_new(sb, first_not_zeroed);
3144 	if (!elr) {
3145 		ret = -ENOMEM;
3146 		goto out;
3147 	}
3148 
3149 	if (NULL == ext4_li_info) {
3150 		ret = ext4_li_info_new();
3151 		if (ret)
3152 			goto out;
3153 	}
3154 
3155 	mutex_lock(&ext4_li_info->li_list_mtx);
3156 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3157 	mutex_unlock(&ext4_li_info->li_list_mtx);
3158 
3159 	sbi->s_li_request = elr;
3160 	/*
3161 	 * set elr to NULL here since it has been inserted to
3162 	 * the request_list and the removal and free of it is
3163 	 * handled by ext4_clear_request_list from now on.
3164 	 */
3165 	elr = NULL;
3166 
3167 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3168 		ret = ext4_run_lazyinit_thread();
3169 		if (ret)
3170 			goto out;
3171 	}
3172 out:
3173 	mutex_unlock(&ext4_li_mtx);
3174 	if (ret)
3175 		kfree(elr);
3176 	return ret;
3177 }
3178 
3179 /*
3180  * We do not need to lock anything since this is called on
3181  * module unload.
3182  */
3183 static void ext4_destroy_lazyinit_thread(void)
3184 {
3185 	/*
3186 	 * If thread exited earlier
3187 	 * there's nothing to be done.
3188 	 */
3189 	if (!ext4_li_info || !ext4_lazyinit_task)
3190 		return;
3191 
3192 	kthread_stop(ext4_lazyinit_task);
3193 }
3194 
3195 static int set_journal_csum_feature_set(struct super_block *sb)
3196 {
3197 	int ret = 1;
3198 	int compat, incompat;
3199 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3200 
3201 	if (ext4_has_metadata_csum(sb)) {
3202 		/* journal checksum v3 */
3203 		compat = 0;
3204 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3205 	} else {
3206 		/* journal checksum v1 */
3207 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3208 		incompat = 0;
3209 	}
3210 
3211 	jbd2_journal_clear_features(sbi->s_journal,
3212 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3213 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3214 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3215 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3216 		ret = jbd2_journal_set_features(sbi->s_journal,
3217 				compat, 0,
3218 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3219 				incompat);
3220 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3221 		ret = jbd2_journal_set_features(sbi->s_journal,
3222 				compat, 0,
3223 				incompat);
3224 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3225 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3226 	} else {
3227 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3228 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3229 	}
3230 
3231 	return ret;
3232 }
3233 
3234 /*
3235  * Note: calculating the overhead so we can be compatible with
3236  * historical BSD practice is quite difficult in the face of
3237  * clusters/bigalloc.  This is because multiple metadata blocks from
3238  * different block group can end up in the same allocation cluster.
3239  * Calculating the exact overhead in the face of clustered allocation
3240  * requires either O(all block bitmaps) in memory or O(number of block
3241  * groups**2) in time.  We will still calculate the superblock for
3242  * older file systems --- and if we come across with a bigalloc file
3243  * system with zero in s_overhead_clusters the estimate will be close to
3244  * correct especially for very large cluster sizes --- but for newer
3245  * file systems, it's better to calculate this figure once at mkfs
3246  * time, and store it in the superblock.  If the superblock value is
3247  * present (even for non-bigalloc file systems), we will use it.
3248  */
3249 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3250 			  char *buf)
3251 {
3252 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3253 	struct ext4_group_desc	*gdp;
3254 	ext4_fsblk_t		first_block, last_block, b;
3255 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3256 	int			s, j, count = 0;
3257 
3258 	if (!ext4_has_feature_bigalloc(sb))
3259 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3260 			sbi->s_itb_per_group + 2);
3261 
3262 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3263 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3264 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3265 	for (i = 0; i < ngroups; i++) {
3266 		gdp = ext4_get_group_desc(sb, i, NULL);
3267 		b = ext4_block_bitmap(sb, gdp);
3268 		if (b >= first_block && b <= last_block) {
3269 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3270 			count++;
3271 		}
3272 		b = ext4_inode_bitmap(sb, gdp);
3273 		if (b >= first_block && b <= last_block) {
3274 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3275 			count++;
3276 		}
3277 		b = ext4_inode_table(sb, gdp);
3278 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3279 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3280 				int c = EXT4_B2C(sbi, b - first_block);
3281 				ext4_set_bit(c, buf);
3282 				count++;
3283 			}
3284 		if (i != grp)
3285 			continue;
3286 		s = 0;
3287 		if (ext4_bg_has_super(sb, grp)) {
3288 			ext4_set_bit(s++, buf);
3289 			count++;
3290 		}
3291 		j = ext4_bg_num_gdb(sb, grp);
3292 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3293 			ext4_error(sb, "Invalid number of block group "
3294 				   "descriptor blocks: %d", j);
3295 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3296 		}
3297 		count += j;
3298 		for (; j > 0; j--)
3299 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3300 	}
3301 	if (!count)
3302 		return 0;
3303 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3304 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3305 }
3306 
3307 /*
3308  * Compute the overhead and stash it in sbi->s_overhead
3309  */
3310 int ext4_calculate_overhead(struct super_block *sb)
3311 {
3312 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3313 	struct ext4_super_block *es = sbi->s_es;
3314 	struct inode *j_inode;
3315 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3316 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3317 	ext4_fsblk_t overhead = 0;
3318 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3319 
3320 	if (!buf)
3321 		return -ENOMEM;
3322 
3323 	/*
3324 	 * Compute the overhead (FS structures).  This is constant
3325 	 * for a given filesystem unless the number of block groups
3326 	 * changes so we cache the previous value until it does.
3327 	 */
3328 
3329 	/*
3330 	 * All of the blocks before first_data_block are overhead
3331 	 */
3332 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3333 
3334 	/*
3335 	 * Add the overhead found in each block group
3336 	 */
3337 	for (i = 0; i < ngroups; i++) {
3338 		int blks;
3339 
3340 		blks = count_overhead(sb, i, buf);
3341 		overhead += blks;
3342 		if (blks)
3343 			memset(buf, 0, PAGE_SIZE);
3344 		cond_resched();
3345 	}
3346 
3347 	/*
3348 	 * Add the internal journal blocks whether the journal has been
3349 	 * loaded or not
3350 	 */
3351 	if (sbi->s_journal && !sbi->journal_bdev)
3352 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3353 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3354 		j_inode = ext4_get_journal_inode(sb, j_inum);
3355 		if (j_inode) {
3356 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3357 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3358 			iput(j_inode);
3359 		} else {
3360 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3361 		}
3362 	}
3363 	sbi->s_overhead = overhead;
3364 	smp_wmb();
3365 	free_page((unsigned long) buf);
3366 	return 0;
3367 }
3368 
3369 static void ext4_set_resv_clusters(struct super_block *sb)
3370 {
3371 	ext4_fsblk_t resv_clusters;
3372 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3373 
3374 	/*
3375 	 * There's no need to reserve anything when we aren't using extents.
3376 	 * The space estimates are exact, there are no unwritten extents,
3377 	 * hole punching doesn't need new metadata... This is needed especially
3378 	 * to keep ext2/3 backward compatibility.
3379 	 */
3380 	if (!ext4_has_feature_extents(sb))
3381 		return;
3382 	/*
3383 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3384 	 * This should cover the situations where we can not afford to run
3385 	 * out of space like for example punch hole, or converting
3386 	 * unwritten extents in delalloc path. In most cases such
3387 	 * allocation would require 1, or 2 blocks, higher numbers are
3388 	 * very rare.
3389 	 */
3390 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3391 			 sbi->s_cluster_bits);
3392 
3393 	do_div(resv_clusters, 50);
3394 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3395 
3396 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3397 }
3398 
3399 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3400 {
3401 	char *orig_data = kstrdup(data, GFP_KERNEL);
3402 	struct buffer_head *bh;
3403 	struct ext4_super_block *es = NULL;
3404 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3405 	ext4_fsblk_t block;
3406 	ext4_fsblk_t sb_block = get_sb_block(&data);
3407 	ext4_fsblk_t logical_sb_block;
3408 	unsigned long offset = 0;
3409 	unsigned long journal_devnum = 0;
3410 	unsigned long def_mount_opts;
3411 	struct inode *root;
3412 	const char *descr;
3413 	int ret = -ENOMEM;
3414 	int blocksize, clustersize;
3415 	unsigned int db_count;
3416 	unsigned int i;
3417 	int needs_recovery, has_huge_files, has_bigalloc;
3418 	__u64 blocks_count;
3419 	int err = 0;
3420 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3421 	ext4_group_t first_not_zeroed;
3422 
3423 	if ((data && !orig_data) || !sbi)
3424 		goto out_free_base;
3425 
3426 	sbi->s_blockgroup_lock =
3427 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3428 	if (!sbi->s_blockgroup_lock)
3429 		goto out_free_base;
3430 
3431 	sb->s_fs_info = sbi;
3432 	sbi->s_sb = sb;
3433 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3434 	sbi->s_sb_block = sb_block;
3435 	if (sb->s_bdev->bd_part)
3436 		sbi->s_sectors_written_start =
3437 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3438 
3439 	/* Cleanup superblock name */
3440 	strreplace(sb->s_id, '/', '!');
3441 
3442 	/* -EINVAL is default */
3443 	ret = -EINVAL;
3444 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3445 	if (!blocksize) {
3446 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3447 		goto out_fail;
3448 	}
3449 
3450 	/*
3451 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3452 	 * block sizes.  We need to calculate the offset from buffer start.
3453 	 */
3454 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3455 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3456 		offset = do_div(logical_sb_block, blocksize);
3457 	} else {
3458 		logical_sb_block = sb_block;
3459 	}
3460 
3461 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3462 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3463 		goto out_fail;
3464 	}
3465 	/*
3466 	 * Note: s_es must be initialized as soon as possible because
3467 	 *       some ext4 macro-instructions depend on its value
3468 	 */
3469 	es = (struct ext4_super_block *) (bh->b_data + offset);
3470 	sbi->s_es = es;
3471 	sb->s_magic = le16_to_cpu(es->s_magic);
3472 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3473 		goto cantfind_ext4;
3474 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3475 
3476 	/* Warn if metadata_csum and gdt_csum are both set. */
3477 	if (ext4_has_feature_metadata_csum(sb) &&
3478 	    ext4_has_feature_gdt_csum(sb))
3479 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3480 			     "redundant flags; please run fsck.");
3481 
3482 	/* Check for a known checksum algorithm */
3483 	if (!ext4_verify_csum_type(sb, es)) {
3484 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3485 			 "unknown checksum algorithm.");
3486 		silent = 1;
3487 		goto cantfind_ext4;
3488 	}
3489 
3490 	/* Load the checksum driver */
3491 	if (ext4_has_feature_metadata_csum(sb) ||
3492 	    ext4_has_feature_ea_inode(sb)) {
3493 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3494 		if (IS_ERR(sbi->s_chksum_driver)) {
3495 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3496 			ret = PTR_ERR(sbi->s_chksum_driver);
3497 			sbi->s_chksum_driver = NULL;
3498 			goto failed_mount;
3499 		}
3500 	}
3501 
3502 	/* Check superblock checksum */
3503 	if (!ext4_superblock_csum_verify(sb, es)) {
3504 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3505 			 "invalid superblock checksum.  Run e2fsck?");
3506 		silent = 1;
3507 		ret = -EFSBADCRC;
3508 		goto cantfind_ext4;
3509 	}
3510 
3511 	/* Precompute checksum seed for all metadata */
3512 	if (ext4_has_feature_csum_seed(sb))
3513 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3514 	else if (ext4_has_metadata_csum(sb) || ext4_has_feature_ea_inode(sb))
3515 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3516 					       sizeof(es->s_uuid));
3517 
3518 	/* Set defaults before we parse the mount options */
3519 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3520 	set_opt(sb, INIT_INODE_TABLE);
3521 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3522 		set_opt(sb, DEBUG);
3523 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3524 		set_opt(sb, GRPID);
3525 	if (def_mount_opts & EXT4_DEFM_UID16)
3526 		set_opt(sb, NO_UID32);
3527 	/* xattr user namespace & acls are now defaulted on */
3528 	set_opt(sb, XATTR_USER);
3529 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3530 	set_opt(sb, POSIX_ACL);
3531 #endif
3532 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3533 	if (ext4_has_metadata_csum(sb))
3534 		set_opt(sb, JOURNAL_CHECKSUM);
3535 
3536 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3537 		set_opt(sb, JOURNAL_DATA);
3538 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3539 		set_opt(sb, ORDERED_DATA);
3540 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3541 		set_opt(sb, WRITEBACK_DATA);
3542 
3543 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3544 		set_opt(sb, ERRORS_PANIC);
3545 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3546 		set_opt(sb, ERRORS_CONT);
3547 	else
3548 		set_opt(sb, ERRORS_RO);
3549 	/* block_validity enabled by default; disable with noblock_validity */
3550 	set_opt(sb, BLOCK_VALIDITY);
3551 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3552 		set_opt(sb, DISCARD);
3553 
3554 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3555 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3556 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3557 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3558 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3559 
3560 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3561 		set_opt(sb, BARRIER);
3562 
3563 	/*
3564 	 * enable delayed allocation by default
3565 	 * Use -o nodelalloc to turn it off
3566 	 */
3567 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3568 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3569 		set_opt(sb, DELALLOC);
3570 
3571 	/*
3572 	 * set default s_li_wait_mult for lazyinit, for the case there is
3573 	 * no mount option specified.
3574 	 */
3575 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3576 
3577 	if (sbi->s_es->s_mount_opts[0]) {
3578 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3579 					      sizeof(sbi->s_es->s_mount_opts),
3580 					      GFP_KERNEL);
3581 		if (!s_mount_opts)
3582 			goto failed_mount;
3583 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3584 				   &journal_ioprio, 0)) {
3585 			ext4_msg(sb, KERN_WARNING,
3586 				 "failed to parse options in superblock: %s",
3587 				 s_mount_opts);
3588 		}
3589 		kfree(s_mount_opts);
3590 	}
3591 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3592 	if (!parse_options((char *) data, sb, &journal_devnum,
3593 			   &journal_ioprio, 0))
3594 		goto failed_mount;
3595 
3596 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3597 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3598 			    "with data=journal disables delayed "
3599 			    "allocation and O_DIRECT support!\n");
3600 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3601 			ext4_msg(sb, KERN_ERR, "can't mount with "
3602 				 "both data=journal and delalloc");
3603 			goto failed_mount;
3604 		}
3605 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3606 			ext4_msg(sb, KERN_ERR, "can't mount with "
3607 				 "both data=journal and dioread_nolock");
3608 			goto failed_mount;
3609 		}
3610 		if (test_opt(sb, DAX)) {
3611 			ext4_msg(sb, KERN_ERR, "can't mount with "
3612 				 "both data=journal and dax");
3613 			goto failed_mount;
3614 		}
3615 		if (ext4_has_feature_encrypt(sb)) {
3616 			ext4_msg(sb, KERN_WARNING,
3617 				 "encrypted files will use data=ordered "
3618 				 "instead of data journaling mode");
3619 		}
3620 		if (test_opt(sb, DELALLOC))
3621 			clear_opt(sb, DELALLOC);
3622 	} else {
3623 		sb->s_iflags |= SB_I_CGROUPWB;
3624 	}
3625 
3626 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3627 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3628 
3629 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3630 	    (ext4_has_compat_features(sb) ||
3631 	     ext4_has_ro_compat_features(sb) ||
3632 	     ext4_has_incompat_features(sb)))
3633 		ext4_msg(sb, KERN_WARNING,
3634 		       "feature flags set on rev 0 fs, "
3635 		       "running e2fsck is recommended");
3636 
3637 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3638 		set_opt2(sb, HURD_COMPAT);
3639 		if (ext4_has_feature_64bit(sb)) {
3640 			ext4_msg(sb, KERN_ERR,
3641 				 "The Hurd can't support 64-bit file systems");
3642 			goto failed_mount;
3643 		}
3644 
3645 		/*
3646 		 * ea_inode feature uses l_i_version field which is not
3647 		 * available in HURD_COMPAT mode.
3648 		 */
3649 		if (ext4_has_feature_ea_inode(sb)) {
3650 			ext4_msg(sb, KERN_ERR,
3651 				 "ea_inode feature is not supported for Hurd");
3652 			goto failed_mount;
3653 		}
3654 	}
3655 
3656 	if (IS_EXT2_SB(sb)) {
3657 		if (ext2_feature_set_ok(sb))
3658 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3659 				 "using the ext4 subsystem");
3660 		else {
3661 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3662 				 "to feature incompatibilities");
3663 			goto failed_mount;
3664 		}
3665 	}
3666 
3667 	if (IS_EXT3_SB(sb)) {
3668 		if (ext3_feature_set_ok(sb))
3669 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3670 				 "using the ext4 subsystem");
3671 		else {
3672 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3673 				 "to feature incompatibilities");
3674 			goto failed_mount;
3675 		}
3676 	}
3677 
3678 	/*
3679 	 * Check feature flags regardless of the revision level, since we
3680 	 * previously didn't change the revision level when setting the flags,
3681 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3682 	 */
3683 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3684 		goto failed_mount;
3685 
3686 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3687 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3688 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3689 		ext4_msg(sb, KERN_ERR,
3690 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3691 			 blocksize, le32_to_cpu(es->s_log_block_size));
3692 		goto failed_mount;
3693 	}
3694 	if (le32_to_cpu(es->s_log_block_size) >
3695 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3696 		ext4_msg(sb, KERN_ERR,
3697 			 "Invalid log block size: %u",
3698 			 le32_to_cpu(es->s_log_block_size));
3699 		goto failed_mount;
3700 	}
3701 
3702 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3703 		ext4_msg(sb, KERN_ERR,
3704 			 "Number of reserved GDT blocks insanely large: %d",
3705 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3706 		goto failed_mount;
3707 	}
3708 
3709 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3710 		err = bdev_dax_supported(sb, blocksize);
3711 		if (err)
3712 			goto failed_mount;
3713 	}
3714 
3715 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3716 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3717 			 es->s_encryption_level);
3718 		goto failed_mount;
3719 	}
3720 
3721 	if (sb->s_blocksize != blocksize) {
3722 		/* Validate the filesystem blocksize */
3723 		if (!sb_set_blocksize(sb, blocksize)) {
3724 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3725 					blocksize);
3726 			goto failed_mount;
3727 		}
3728 
3729 		brelse(bh);
3730 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3731 		offset = do_div(logical_sb_block, blocksize);
3732 		bh = sb_bread_unmovable(sb, logical_sb_block);
3733 		if (!bh) {
3734 			ext4_msg(sb, KERN_ERR,
3735 			       "Can't read superblock on 2nd try");
3736 			goto failed_mount;
3737 		}
3738 		es = (struct ext4_super_block *)(bh->b_data + offset);
3739 		sbi->s_es = es;
3740 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3741 			ext4_msg(sb, KERN_ERR,
3742 			       "Magic mismatch, very weird!");
3743 			goto failed_mount;
3744 		}
3745 	}
3746 
3747 	has_huge_files = ext4_has_feature_huge_file(sb);
3748 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3749 						      has_huge_files);
3750 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3751 
3752 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3753 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3754 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3755 	} else {
3756 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3757 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3758 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3759 		    (!is_power_of_2(sbi->s_inode_size)) ||
3760 		    (sbi->s_inode_size > blocksize)) {
3761 			ext4_msg(sb, KERN_ERR,
3762 			       "unsupported inode size: %d",
3763 			       sbi->s_inode_size);
3764 			goto failed_mount;
3765 		}
3766 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3767 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3768 	}
3769 
3770 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3771 	if (ext4_has_feature_64bit(sb)) {
3772 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3773 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3774 		    !is_power_of_2(sbi->s_desc_size)) {
3775 			ext4_msg(sb, KERN_ERR,
3776 			       "unsupported descriptor size %lu",
3777 			       sbi->s_desc_size);
3778 			goto failed_mount;
3779 		}
3780 	} else
3781 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3782 
3783 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3784 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3785 
3786 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3787 	if (sbi->s_inodes_per_block == 0)
3788 		goto cantfind_ext4;
3789 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3790 	    sbi->s_inodes_per_group > blocksize * 8) {
3791 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3792 			 sbi->s_blocks_per_group);
3793 		goto failed_mount;
3794 	}
3795 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3796 					sbi->s_inodes_per_block;
3797 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3798 	sbi->s_sbh = bh;
3799 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3800 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3801 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3802 
3803 	for (i = 0; i < 4; i++)
3804 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3805 	sbi->s_def_hash_version = es->s_def_hash_version;
3806 	if (ext4_has_feature_dir_index(sb)) {
3807 		i = le32_to_cpu(es->s_flags);
3808 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3809 			sbi->s_hash_unsigned = 3;
3810 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3811 #ifdef __CHAR_UNSIGNED__
3812 			if (!(sb->s_flags & MS_RDONLY))
3813 				es->s_flags |=
3814 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3815 			sbi->s_hash_unsigned = 3;
3816 #else
3817 			if (!(sb->s_flags & MS_RDONLY))
3818 				es->s_flags |=
3819 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3820 #endif
3821 		}
3822 	}
3823 
3824 	/* Handle clustersize */
3825 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3826 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3827 	if (has_bigalloc) {
3828 		if (clustersize < blocksize) {
3829 			ext4_msg(sb, KERN_ERR,
3830 				 "cluster size (%d) smaller than "
3831 				 "block size (%d)", clustersize, blocksize);
3832 			goto failed_mount;
3833 		}
3834 		if (le32_to_cpu(es->s_log_cluster_size) >
3835 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3836 			ext4_msg(sb, KERN_ERR,
3837 				 "Invalid log cluster size: %u",
3838 				 le32_to_cpu(es->s_log_cluster_size));
3839 			goto failed_mount;
3840 		}
3841 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3842 			le32_to_cpu(es->s_log_block_size);
3843 		sbi->s_clusters_per_group =
3844 			le32_to_cpu(es->s_clusters_per_group);
3845 		if (sbi->s_clusters_per_group > blocksize * 8) {
3846 			ext4_msg(sb, KERN_ERR,
3847 				 "#clusters per group too big: %lu",
3848 				 sbi->s_clusters_per_group);
3849 			goto failed_mount;
3850 		}
3851 		if (sbi->s_blocks_per_group !=
3852 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3853 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3854 				 "clusters per group (%lu) inconsistent",
3855 				 sbi->s_blocks_per_group,
3856 				 sbi->s_clusters_per_group);
3857 			goto failed_mount;
3858 		}
3859 	} else {
3860 		if (clustersize != blocksize) {
3861 			ext4_warning(sb, "fragment/cluster size (%d) != "
3862 				     "block size (%d)", clustersize,
3863 				     blocksize);
3864 			clustersize = blocksize;
3865 		}
3866 		if (sbi->s_blocks_per_group > blocksize * 8) {
3867 			ext4_msg(sb, KERN_ERR,
3868 				 "#blocks per group too big: %lu",
3869 				 sbi->s_blocks_per_group);
3870 			goto failed_mount;
3871 		}
3872 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3873 		sbi->s_cluster_bits = 0;
3874 	}
3875 	sbi->s_cluster_ratio = clustersize / blocksize;
3876 
3877 	/* Do we have standard group size of clustersize * 8 blocks ? */
3878 	if (sbi->s_blocks_per_group == clustersize << 3)
3879 		set_opt2(sb, STD_GROUP_SIZE);
3880 
3881 	/*
3882 	 * Test whether we have more sectors than will fit in sector_t,
3883 	 * and whether the max offset is addressable by the page cache.
3884 	 */
3885 	err = generic_check_addressable(sb->s_blocksize_bits,
3886 					ext4_blocks_count(es));
3887 	if (err) {
3888 		ext4_msg(sb, KERN_ERR, "filesystem"
3889 			 " too large to mount safely on this system");
3890 		if (sizeof(sector_t) < 8)
3891 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3892 		goto failed_mount;
3893 	}
3894 
3895 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3896 		goto cantfind_ext4;
3897 
3898 	/* check blocks count against device size */
3899 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3900 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3901 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3902 		       "exceeds size of device (%llu blocks)",
3903 		       ext4_blocks_count(es), blocks_count);
3904 		goto failed_mount;
3905 	}
3906 
3907 	/*
3908 	 * It makes no sense for the first data block to be beyond the end
3909 	 * of the filesystem.
3910 	 */
3911 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3912 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3913 			 "block %u is beyond end of filesystem (%llu)",
3914 			 le32_to_cpu(es->s_first_data_block),
3915 			 ext4_blocks_count(es));
3916 		goto failed_mount;
3917 	}
3918 	blocks_count = (ext4_blocks_count(es) -
3919 			le32_to_cpu(es->s_first_data_block) +
3920 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3921 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3922 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3923 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3924 		       "(block count %llu, first data block %u, "
3925 		       "blocks per group %lu)", sbi->s_groups_count,
3926 		       ext4_blocks_count(es),
3927 		       le32_to_cpu(es->s_first_data_block),
3928 		       EXT4_BLOCKS_PER_GROUP(sb));
3929 		goto failed_mount;
3930 	}
3931 	sbi->s_groups_count = blocks_count;
3932 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3933 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3934 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3935 		   EXT4_DESC_PER_BLOCK(sb);
3936 	if (ext4_has_feature_meta_bg(sb)) {
3937 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3938 			ext4_msg(sb, KERN_WARNING,
3939 				 "first meta block group too large: %u "
3940 				 "(group descriptor block count %u)",
3941 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3942 			goto failed_mount;
3943 		}
3944 	}
3945 	sbi->s_group_desc = kvmalloc(db_count *
3946 					  sizeof(struct buffer_head *),
3947 					  GFP_KERNEL);
3948 	if (sbi->s_group_desc == NULL) {
3949 		ext4_msg(sb, KERN_ERR, "not enough memory");
3950 		ret = -ENOMEM;
3951 		goto failed_mount;
3952 	}
3953 
3954 	bgl_lock_init(sbi->s_blockgroup_lock);
3955 
3956 	/* Pre-read the descriptors into the buffer cache */
3957 	for (i = 0; i < db_count; i++) {
3958 		block = descriptor_loc(sb, logical_sb_block, i);
3959 		sb_breadahead(sb, block);
3960 	}
3961 
3962 	for (i = 0; i < db_count; i++) {
3963 		block = descriptor_loc(sb, logical_sb_block, i);
3964 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3965 		if (!sbi->s_group_desc[i]) {
3966 			ext4_msg(sb, KERN_ERR,
3967 			       "can't read group descriptor %d", i);
3968 			db_count = i;
3969 			goto failed_mount2;
3970 		}
3971 	}
3972 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3973 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3974 		ret = -EFSCORRUPTED;
3975 		goto failed_mount2;
3976 	}
3977 
3978 	sbi->s_gdb_count = db_count;
3979 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3980 	spin_lock_init(&sbi->s_next_gen_lock);
3981 
3982 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3983 		(unsigned long) sb);
3984 
3985 	/* Register extent status tree shrinker */
3986 	if (ext4_es_register_shrinker(sbi))
3987 		goto failed_mount3;
3988 
3989 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3990 	sbi->s_extent_max_zeroout_kb = 32;
3991 
3992 	/*
3993 	 * set up enough so that it can read an inode
3994 	 */
3995 	sb->s_op = &ext4_sops;
3996 	sb->s_export_op = &ext4_export_ops;
3997 	sb->s_xattr = ext4_xattr_handlers;
3998 	sb->s_cop = &ext4_cryptops;
3999 #ifdef CONFIG_QUOTA
4000 	sb->dq_op = &ext4_quota_operations;
4001 	if (ext4_has_feature_quota(sb))
4002 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
4003 	else
4004 		sb->s_qcop = &ext4_qctl_operations;
4005 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
4006 #endif
4007 	memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
4008 
4009 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
4010 	mutex_init(&sbi->s_orphan_lock);
4011 
4012 	sb->s_root = NULL;
4013 
4014 	needs_recovery = (es->s_last_orphan != 0 ||
4015 			  ext4_has_feature_journal_needs_recovery(sb));
4016 
4017 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
4018 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
4019 			goto failed_mount3a;
4020 
4021 	/*
4022 	 * The first inode we look at is the journal inode.  Don't try
4023 	 * root first: it may be modified in the journal!
4024 	 */
4025 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
4026 		err = ext4_load_journal(sb, es, journal_devnum);
4027 		if (err)
4028 			goto failed_mount3a;
4029 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
4030 		   ext4_has_feature_journal_needs_recovery(sb)) {
4031 		ext4_msg(sb, KERN_ERR, "required journal recovery "
4032 		       "suppressed and not mounted read-only");
4033 		goto failed_mount_wq;
4034 	} else {
4035 		/* Nojournal mode, all journal mount options are illegal */
4036 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
4037 			ext4_msg(sb, KERN_ERR, "can't mount with "
4038 				 "journal_checksum, fs mounted w/o journal");
4039 			goto failed_mount_wq;
4040 		}
4041 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4042 			ext4_msg(sb, KERN_ERR, "can't mount with "
4043 				 "journal_async_commit, fs mounted w/o journal");
4044 			goto failed_mount_wq;
4045 		}
4046 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
4047 			ext4_msg(sb, KERN_ERR, "can't mount with "
4048 				 "commit=%lu, fs mounted w/o journal",
4049 				 sbi->s_commit_interval / HZ);
4050 			goto failed_mount_wq;
4051 		}
4052 		if (EXT4_MOUNT_DATA_FLAGS &
4053 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4054 			ext4_msg(sb, KERN_ERR, "can't mount with "
4055 				 "data=, fs mounted w/o journal");
4056 			goto failed_mount_wq;
4057 		}
4058 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4059 		clear_opt(sb, JOURNAL_CHECKSUM);
4060 		clear_opt(sb, DATA_FLAGS);
4061 		sbi->s_journal = NULL;
4062 		needs_recovery = 0;
4063 		goto no_journal;
4064 	}
4065 
4066 	if (ext4_has_feature_64bit(sb) &&
4067 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4068 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4069 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4070 		goto failed_mount_wq;
4071 	}
4072 
4073 	if (!set_journal_csum_feature_set(sb)) {
4074 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4075 			 "feature set");
4076 		goto failed_mount_wq;
4077 	}
4078 
4079 	/* We have now updated the journal if required, so we can
4080 	 * validate the data journaling mode. */
4081 	switch (test_opt(sb, DATA_FLAGS)) {
4082 	case 0:
4083 		/* No mode set, assume a default based on the journal
4084 		 * capabilities: ORDERED_DATA if the journal can
4085 		 * cope, else JOURNAL_DATA
4086 		 */
4087 		if (jbd2_journal_check_available_features
4088 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4089 			set_opt(sb, ORDERED_DATA);
4090 		else
4091 			set_opt(sb, JOURNAL_DATA);
4092 		break;
4093 
4094 	case EXT4_MOUNT_ORDERED_DATA:
4095 	case EXT4_MOUNT_WRITEBACK_DATA:
4096 		if (!jbd2_journal_check_available_features
4097 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4098 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4099 			       "requested data journaling mode");
4100 			goto failed_mount_wq;
4101 		}
4102 	default:
4103 		break;
4104 	}
4105 
4106 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4107 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4108 		ext4_msg(sb, KERN_ERR, "can't mount with "
4109 			"journal_async_commit in data=ordered mode");
4110 		goto failed_mount_wq;
4111 	}
4112 
4113 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4114 
4115 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4116 
4117 no_journal:
4118 	if (!test_opt(sb, NO_MBCACHE)) {
4119 		sbi->s_ea_block_cache = ext4_xattr_create_cache();
4120 		if (!sbi->s_ea_block_cache) {
4121 			ext4_msg(sb, KERN_ERR,
4122 				 "Failed to create ea_block_cache");
4123 			goto failed_mount_wq;
4124 		}
4125 
4126 		if (ext4_has_feature_ea_inode(sb)) {
4127 			sbi->s_ea_inode_cache = ext4_xattr_create_cache();
4128 			if (!sbi->s_ea_inode_cache) {
4129 				ext4_msg(sb, KERN_ERR,
4130 					 "Failed to create ea_inode_cache");
4131 				goto failed_mount_wq;
4132 			}
4133 		}
4134 	}
4135 
4136 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4137 	    (blocksize != PAGE_SIZE)) {
4138 		ext4_msg(sb, KERN_ERR,
4139 			 "Unsupported blocksize for fs encryption");
4140 		goto failed_mount_wq;
4141 	}
4142 
4143 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4144 	    !ext4_has_feature_encrypt(sb)) {
4145 		ext4_set_feature_encrypt(sb);
4146 		ext4_commit_super(sb, 1);
4147 	}
4148 
4149 	/*
4150 	 * Get the # of file system overhead blocks from the
4151 	 * superblock if present.
4152 	 */
4153 	if (es->s_overhead_clusters)
4154 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4155 	else {
4156 		err = ext4_calculate_overhead(sb);
4157 		if (err)
4158 			goto failed_mount_wq;
4159 	}
4160 
4161 	/*
4162 	 * The maximum number of concurrent works can be high and
4163 	 * concurrency isn't really necessary.  Limit it to 1.
4164 	 */
4165 	EXT4_SB(sb)->rsv_conversion_wq =
4166 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4167 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4168 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4169 		ret = -ENOMEM;
4170 		goto failed_mount4;
4171 	}
4172 
4173 	/*
4174 	 * The jbd2_journal_load will have done any necessary log recovery,
4175 	 * so we can safely mount the rest of the filesystem now.
4176 	 */
4177 
4178 	root = ext4_iget(sb, EXT4_ROOT_INO);
4179 	if (IS_ERR(root)) {
4180 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4181 		ret = PTR_ERR(root);
4182 		root = NULL;
4183 		goto failed_mount4;
4184 	}
4185 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4186 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4187 		iput(root);
4188 		goto failed_mount4;
4189 	}
4190 	sb->s_root = d_make_root(root);
4191 	if (!sb->s_root) {
4192 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4193 		ret = -ENOMEM;
4194 		goto failed_mount4;
4195 	}
4196 
4197 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4198 		sb->s_flags |= MS_RDONLY;
4199 
4200 	/* determine the minimum size of new large inodes, if present */
4201 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4202 	    sbi->s_want_extra_isize == 0) {
4203 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4204 						     EXT4_GOOD_OLD_INODE_SIZE;
4205 		if (ext4_has_feature_extra_isize(sb)) {
4206 			if (sbi->s_want_extra_isize <
4207 			    le16_to_cpu(es->s_want_extra_isize))
4208 				sbi->s_want_extra_isize =
4209 					le16_to_cpu(es->s_want_extra_isize);
4210 			if (sbi->s_want_extra_isize <
4211 			    le16_to_cpu(es->s_min_extra_isize))
4212 				sbi->s_want_extra_isize =
4213 					le16_to_cpu(es->s_min_extra_isize);
4214 		}
4215 	}
4216 	/* Check if enough inode space is available */
4217 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4218 							sbi->s_inode_size) {
4219 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4220 						       EXT4_GOOD_OLD_INODE_SIZE;
4221 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4222 			 "available");
4223 	}
4224 
4225 	ext4_set_resv_clusters(sb);
4226 
4227 	err = ext4_setup_system_zone(sb);
4228 	if (err) {
4229 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4230 			 "zone (%d)", err);
4231 		goto failed_mount4a;
4232 	}
4233 
4234 	ext4_ext_init(sb);
4235 	err = ext4_mb_init(sb);
4236 	if (err) {
4237 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4238 			 err);
4239 		goto failed_mount5;
4240 	}
4241 
4242 	block = ext4_count_free_clusters(sb);
4243 	ext4_free_blocks_count_set(sbi->s_es,
4244 				   EXT4_C2B(sbi, block));
4245 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4246 				  GFP_KERNEL);
4247 	if (!err) {
4248 		unsigned long freei = ext4_count_free_inodes(sb);
4249 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4250 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4251 					  GFP_KERNEL);
4252 	}
4253 	if (!err)
4254 		err = percpu_counter_init(&sbi->s_dirs_counter,
4255 					  ext4_count_dirs(sb), GFP_KERNEL);
4256 	if (!err)
4257 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4258 					  GFP_KERNEL);
4259 	if (!err)
4260 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4261 
4262 	if (err) {
4263 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4264 		goto failed_mount6;
4265 	}
4266 
4267 	if (ext4_has_feature_flex_bg(sb))
4268 		if (!ext4_fill_flex_info(sb)) {
4269 			ext4_msg(sb, KERN_ERR,
4270 			       "unable to initialize "
4271 			       "flex_bg meta info!");
4272 			goto failed_mount6;
4273 		}
4274 
4275 	err = ext4_register_li_request(sb, first_not_zeroed);
4276 	if (err)
4277 		goto failed_mount6;
4278 
4279 	err = ext4_register_sysfs(sb);
4280 	if (err)
4281 		goto failed_mount7;
4282 
4283 #ifdef CONFIG_QUOTA
4284 	/* Enable quota usage during mount. */
4285 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4286 		err = ext4_enable_quotas(sb);
4287 		if (err)
4288 			goto failed_mount8;
4289 	}
4290 #endif  /* CONFIG_QUOTA */
4291 
4292 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4293 	ext4_orphan_cleanup(sb, es);
4294 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4295 	if (needs_recovery) {
4296 		ext4_msg(sb, KERN_INFO, "recovery complete");
4297 		ext4_mark_recovery_complete(sb, es);
4298 	}
4299 	if (EXT4_SB(sb)->s_journal) {
4300 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4301 			descr = " journalled data mode";
4302 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4303 			descr = " ordered data mode";
4304 		else
4305 			descr = " writeback data mode";
4306 	} else
4307 		descr = "out journal";
4308 
4309 	if (test_opt(sb, DISCARD)) {
4310 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4311 		if (!blk_queue_discard(q))
4312 			ext4_msg(sb, KERN_WARNING,
4313 				 "mounting with \"discard\" option, but "
4314 				 "the device does not support discard");
4315 	}
4316 
4317 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4318 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4319 			 "Opts: %.*s%s%s", descr,
4320 			 (int) sizeof(sbi->s_es->s_mount_opts),
4321 			 sbi->s_es->s_mount_opts,
4322 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4323 
4324 	if (es->s_error_count)
4325 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4326 
4327 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4328 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4329 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4330 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4331 
4332 	kfree(orig_data);
4333 	return 0;
4334 
4335 cantfind_ext4:
4336 	if (!silent)
4337 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4338 	goto failed_mount;
4339 
4340 #ifdef CONFIG_QUOTA
4341 failed_mount8:
4342 	ext4_unregister_sysfs(sb);
4343 #endif
4344 failed_mount7:
4345 	ext4_unregister_li_request(sb);
4346 failed_mount6:
4347 	ext4_mb_release(sb);
4348 	if (sbi->s_flex_groups)
4349 		kvfree(sbi->s_flex_groups);
4350 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4351 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4352 	percpu_counter_destroy(&sbi->s_dirs_counter);
4353 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4354 failed_mount5:
4355 	ext4_ext_release(sb);
4356 	ext4_release_system_zone(sb);
4357 failed_mount4a:
4358 	dput(sb->s_root);
4359 	sb->s_root = NULL;
4360 failed_mount4:
4361 	ext4_msg(sb, KERN_ERR, "mount failed");
4362 	if (EXT4_SB(sb)->rsv_conversion_wq)
4363 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4364 failed_mount_wq:
4365 	if (sbi->s_ea_inode_cache) {
4366 		ext4_xattr_destroy_cache(sbi->s_ea_inode_cache);
4367 		sbi->s_ea_inode_cache = NULL;
4368 	}
4369 	if (sbi->s_ea_block_cache) {
4370 		ext4_xattr_destroy_cache(sbi->s_ea_block_cache);
4371 		sbi->s_ea_block_cache = NULL;
4372 	}
4373 	if (sbi->s_journal) {
4374 		jbd2_journal_destroy(sbi->s_journal);
4375 		sbi->s_journal = NULL;
4376 	}
4377 failed_mount3a:
4378 	ext4_es_unregister_shrinker(sbi);
4379 failed_mount3:
4380 	del_timer_sync(&sbi->s_err_report);
4381 	if (sbi->s_mmp_tsk)
4382 		kthread_stop(sbi->s_mmp_tsk);
4383 failed_mount2:
4384 	for (i = 0; i < db_count; i++)
4385 		brelse(sbi->s_group_desc[i]);
4386 	kvfree(sbi->s_group_desc);
4387 failed_mount:
4388 	if (sbi->s_chksum_driver)
4389 		crypto_free_shash(sbi->s_chksum_driver);
4390 #ifdef CONFIG_QUOTA
4391 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4392 		kfree(sbi->s_qf_names[i]);
4393 #endif
4394 	ext4_blkdev_remove(sbi);
4395 	brelse(bh);
4396 out_fail:
4397 	sb->s_fs_info = NULL;
4398 	kfree(sbi->s_blockgroup_lock);
4399 out_free_base:
4400 	kfree(sbi);
4401 	kfree(orig_data);
4402 	return err ? err : ret;
4403 }
4404 
4405 /*
4406  * Setup any per-fs journal parameters now.  We'll do this both on
4407  * initial mount, once the journal has been initialised but before we've
4408  * done any recovery; and again on any subsequent remount.
4409  */
4410 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4411 {
4412 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4413 
4414 	journal->j_commit_interval = sbi->s_commit_interval;
4415 	journal->j_min_batch_time = sbi->s_min_batch_time;
4416 	journal->j_max_batch_time = sbi->s_max_batch_time;
4417 
4418 	write_lock(&journal->j_state_lock);
4419 	if (test_opt(sb, BARRIER))
4420 		journal->j_flags |= JBD2_BARRIER;
4421 	else
4422 		journal->j_flags &= ~JBD2_BARRIER;
4423 	if (test_opt(sb, DATA_ERR_ABORT))
4424 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4425 	else
4426 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4427 	write_unlock(&journal->j_state_lock);
4428 }
4429 
4430 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4431 					     unsigned int journal_inum)
4432 {
4433 	struct inode *journal_inode;
4434 
4435 	/*
4436 	 * Test for the existence of a valid inode on disk.  Bad things
4437 	 * happen if we iget() an unused inode, as the subsequent iput()
4438 	 * will try to delete it.
4439 	 */
4440 	journal_inode = ext4_iget(sb, journal_inum);
4441 	if (IS_ERR(journal_inode)) {
4442 		ext4_msg(sb, KERN_ERR, "no journal found");
4443 		return NULL;
4444 	}
4445 	if (!journal_inode->i_nlink) {
4446 		make_bad_inode(journal_inode);
4447 		iput(journal_inode);
4448 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4449 		return NULL;
4450 	}
4451 
4452 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4453 		  journal_inode, journal_inode->i_size);
4454 	if (!S_ISREG(journal_inode->i_mode)) {
4455 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4456 		iput(journal_inode);
4457 		return NULL;
4458 	}
4459 	return journal_inode;
4460 }
4461 
4462 static journal_t *ext4_get_journal(struct super_block *sb,
4463 				   unsigned int journal_inum)
4464 {
4465 	struct inode *journal_inode;
4466 	journal_t *journal;
4467 
4468 	BUG_ON(!ext4_has_feature_journal(sb));
4469 
4470 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4471 	if (!journal_inode)
4472 		return NULL;
4473 
4474 	journal = jbd2_journal_init_inode(journal_inode);
4475 	if (!journal) {
4476 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4477 		iput(journal_inode);
4478 		return NULL;
4479 	}
4480 	journal->j_private = sb;
4481 	ext4_init_journal_params(sb, journal);
4482 	return journal;
4483 }
4484 
4485 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4486 				       dev_t j_dev)
4487 {
4488 	struct buffer_head *bh;
4489 	journal_t *journal;
4490 	ext4_fsblk_t start;
4491 	ext4_fsblk_t len;
4492 	int hblock, blocksize;
4493 	ext4_fsblk_t sb_block;
4494 	unsigned long offset;
4495 	struct ext4_super_block *es;
4496 	struct block_device *bdev;
4497 
4498 	BUG_ON(!ext4_has_feature_journal(sb));
4499 
4500 	bdev = ext4_blkdev_get(j_dev, sb);
4501 	if (bdev == NULL)
4502 		return NULL;
4503 
4504 	blocksize = sb->s_blocksize;
4505 	hblock = bdev_logical_block_size(bdev);
4506 	if (blocksize < hblock) {
4507 		ext4_msg(sb, KERN_ERR,
4508 			"blocksize too small for journal device");
4509 		goto out_bdev;
4510 	}
4511 
4512 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4513 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4514 	set_blocksize(bdev, blocksize);
4515 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4516 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4517 		       "external journal");
4518 		goto out_bdev;
4519 	}
4520 
4521 	es = (struct ext4_super_block *) (bh->b_data + offset);
4522 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4523 	    !(le32_to_cpu(es->s_feature_incompat) &
4524 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4525 		ext4_msg(sb, KERN_ERR, "external journal has "
4526 					"bad superblock");
4527 		brelse(bh);
4528 		goto out_bdev;
4529 	}
4530 
4531 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4532 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4533 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4534 		ext4_msg(sb, KERN_ERR, "external journal has "
4535 				       "corrupt superblock");
4536 		brelse(bh);
4537 		goto out_bdev;
4538 	}
4539 
4540 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4541 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4542 		brelse(bh);
4543 		goto out_bdev;
4544 	}
4545 
4546 	len = ext4_blocks_count(es);
4547 	start = sb_block + 1;
4548 	brelse(bh);	/* we're done with the superblock */
4549 
4550 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4551 					start, len, blocksize);
4552 	if (!journal) {
4553 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4554 		goto out_bdev;
4555 	}
4556 	journal->j_private = sb;
4557 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4558 	wait_on_buffer(journal->j_sb_buffer);
4559 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4560 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4561 		goto out_journal;
4562 	}
4563 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4564 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4565 					"user (unsupported) - %d",
4566 			be32_to_cpu(journal->j_superblock->s_nr_users));
4567 		goto out_journal;
4568 	}
4569 	EXT4_SB(sb)->journal_bdev = bdev;
4570 	ext4_init_journal_params(sb, journal);
4571 	return journal;
4572 
4573 out_journal:
4574 	jbd2_journal_destroy(journal);
4575 out_bdev:
4576 	ext4_blkdev_put(bdev);
4577 	return NULL;
4578 }
4579 
4580 static int ext4_load_journal(struct super_block *sb,
4581 			     struct ext4_super_block *es,
4582 			     unsigned long journal_devnum)
4583 {
4584 	journal_t *journal;
4585 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4586 	dev_t journal_dev;
4587 	int err = 0;
4588 	int really_read_only;
4589 
4590 	BUG_ON(!ext4_has_feature_journal(sb));
4591 
4592 	if (journal_devnum &&
4593 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4594 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4595 			"numbers have changed");
4596 		journal_dev = new_decode_dev(journal_devnum);
4597 	} else
4598 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4599 
4600 	really_read_only = bdev_read_only(sb->s_bdev);
4601 
4602 	/*
4603 	 * Are we loading a blank journal or performing recovery after a
4604 	 * crash?  For recovery, we need to check in advance whether we
4605 	 * can get read-write access to the device.
4606 	 */
4607 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4608 		if (sb->s_flags & MS_RDONLY) {
4609 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4610 					"required on readonly filesystem");
4611 			if (really_read_only) {
4612 				ext4_msg(sb, KERN_ERR, "write access "
4613 					"unavailable, cannot proceed");
4614 				return -EROFS;
4615 			}
4616 			ext4_msg(sb, KERN_INFO, "write access will "
4617 			       "be enabled during recovery");
4618 		}
4619 	}
4620 
4621 	if (journal_inum && journal_dev) {
4622 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4623 		       "and inode journals!");
4624 		return -EINVAL;
4625 	}
4626 
4627 	if (journal_inum) {
4628 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4629 			return -EINVAL;
4630 	} else {
4631 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4632 			return -EINVAL;
4633 	}
4634 
4635 	if (!(journal->j_flags & JBD2_BARRIER))
4636 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4637 
4638 	if (!ext4_has_feature_journal_needs_recovery(sb))
4639 		err = jbd2_journal_wipe(journal, !really_read_only);
4640 	if (!err) {
4641 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4642 		if (save)
4643 			memcpy(save, ((char *) es) +
4644 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4645 		err = jbd2_journal_load(journal);
4646 		if (save)
4647 			memcpy(((char *) es) + EXT4_S_ERR_START,
4648 			       save, EXT4_S_ERR_LEN);
4649 		kfree(save);
4650 	}
4651 
4652 	if (err) {
4653 		ext4_msg(sb, KERN_ERR, "error loading journal");
4654 		jbd2_journal_destroy(journal);
4655 		return err;
4656 	}
4657 
4658 	EXT4_SB(sb)->s_journal = journal;
4659 	ext4_clear_journal_err(sb, es);
4660 
4661 	if (!really_read_only && journal_devnum &&
4662 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4663 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4664 
4665 		/* Make sure we flush the recovery flag to disk. */
4666 		ext4_commit_super(sb, 1);
4667 	}
4668 
4669 	return 0;
4670 }
4671 
4672 static int ext4_commit_super(struct super_block *sb, int sync)
4673 {
4674 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4675 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4676 	int error = 0;
4677 
4678 	if (!sbh || block_device_ejected(sb))
4679 		return error;
4680 	/*
4681 	 * If the file system is mounted read-only, don't update the
4682 	 * superblock write time.  This avoids updating the superblock
4683 	 * write time when we are mounting the root file system
4684 	 * read/only but we need to replay the journal; at that point,
4685 	 * for people who are east of GMT and who make their clock
4686 	 * tick in localtime for Windows bug-for-bug compatibility,
4687 	 * the clock is set in the future, and this will cause e2fsck
4688 	 * to complain and force a full file system check.
4689 	 */
4690 	if (!(sb->s_flags & MS_RDONLY))
4691 		es->s_wtime = cpu_to_le32(get_seconds());
4692 	if (sb->s_bdev->bd_part)
4693 		es->s_kbytes_written =
4694 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4695 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4696 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4697 	else
4698 		es->s_kbytes_written =
4699 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4700 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4701 		ext4_free_blocks_count_set(es,
4702 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4703 				&EXT4_SB(sb)->s_freeclusters_counter)));
4704 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4705 		es->s_free_inodes_count =
4706 			cpu_to_le32(percpu_counter_sum_positive(
4707 				&EXT4_SB(sb)->s_freeinodes_counter));
4708 	BUFFER_TRACE(sbh, "marking dirty");
4709 	ext4_superblock_csum_set(sb);
4710 	if (sync)
4711 		lock_buffer(sbh);
4712 	if (buffer_write_io_error(sbh)) {
4713 		/*
4714 		 * Oh, dear.  A previous attempt to write the
4715 		 * superblock failed.  This could happen because the
4716 		 * USB device was yanked out.  Or it could happen to
4717 		 * be a transient write error and maybe the block will
4718 		 * be remapped.  Nothing we can do but to retry the
4719 		 * write and hope for the best.
4720 		 */
4721 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4722 		       "superblock detected");
4723 		clear_buffer_write_io_error(sbh);
4724 		set_buffer_uptodate(sbh);
4725 	}
4726 	mark_buffer_dirty(sbh);
4727 	if (sync) {
4728 		unlock_buffer(sbh);
4729 		error = __sync_dirty_buffer(sbh,
4730 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4731 		if (error)
4732 			return error;
4733 
4734 		error = buffer_write_io_error(sbh);
4735 		if (error) {
4736 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4737 			       "superblock");
4738 			clear_buffer_write_io_error(sbh);
4739 			set_buffer_uptodate(sbh);
4740 		}
4741 	}
4742 	return error;
4743 }
4744 
4745 /*
4746  * Have we just finished recovery?  If so, and if we are mounting (or
4747  * remounting) the filesystem readonly, then we will end up with a
4748  * consistent fs on disk.  Record that fact.
4749  */
4750 static void ext4_mark_recovery_complete(struct super_block *sb,
4751 					struct ext4_super_block *es)
4752 {
4753 	journal_t *journal = EXT4_SB(sb)->s_journal;
4754 
4755 	if (!ext4_has_feature_journal(sb)) {
4756 		BUG_ON(journal != NULL);
4757 		return;
4758 	}
4759 	jbd2_journal_lock_updates(journal);
4760 	if (jbd2_journal_flush(journal) < 0)
4761 		goto out;
4762 
4763 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4764 	    sb->s_flags & MS_RDONLY) {
4765 		ext4_clear_feature_journal_needs_recovery(sb);
4766 		ext4_commit_super(sb, 1);
4767 	}
4768 
4769 out:
4770 	jbd2_journal_unlock_updates(journal);
4771 }
4772 
4773 /*
4774  * If we are mounting (or read-write remounting) a filesystem whose journal
4775  * has recorded an error from a previous lifetime, move that error to the
4776  * main filesystem now.
4777  */
4778 static void ext4_clear_journal_err(struct super_block *sb,
4779 				   struct ext4_super_block *es)
4780 {
4781 	journal_t *journal;
4782 	int j_errno;
4783 	const char *errstr;
4784 
4785 	BUG_ON(!ext4_has_feature_journal(sb));
4786 
4787 	journal = EXT4_SB(sb)->s_journal;
4788 
4789 	/*
4790 	 * Now check for any error status which may have been recorded in the
4791 	 * journal by a prior ext4_error() or ext4_abort()
4792 	 */
4793 
4794 	j_errno = jbd2_journal_errno(journal);
4795 	if (j_errno) {
4796 		char nbuf[16];
4797 
4798 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4799 		ext4_warning(sb, "Filesystem error recorded "
4800 			     "from previous mount: %s", errstr);
4801 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4802 
4803 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4804 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4805 		ext4_commit_super(sb, 1);
4806 
4807 		jbd2_journal_clear_err(journal);
4808 		jbd2_journal_update_sb_errno(journal);
4809 	}
4810 }
4811 
4812 /*
4813  * Force the running and committing transactions to commit,
4814  * and wait on the commit.
4815  */
4816 int ext4_force_commit(struct super_block *sb)
4817 {
4818 	journal_t *journal;
4819 
4820 	if (sb->s_flags & MS_RDONLY)
4821 		return 0;
4822 
4823 	journal = EXT4_SB(sb)->s_journal;
4824 	return ext4_journal_force_commit(journal);
4825 }
4826 
4827 static int ext4_sync_fs(struct super_block *sb, int wait)
4828 {
4829 	int ret = 0;
4830 	tid_t target;
4831 	bool needs_barrier = false;
4832 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4833 
4834 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4835 		return 0;
4836 
4837 	trace_ext4_sync_fs(sb, wait);
4838 	flush_workqueue(sbi->rsv_conversion_wq);
4839 	/*
4840 	 * Writeback quota in non-journalled quota case - journalled quota has
4841 	 * no dirty dquots
4842 	 */
4843 	dquot_writeback_dquots(sb, -1);
4844 	/*
4845 	 * Data writeback is possible w/o journal transaction, so barrier must
4846 	 * being sent at the end of the function. But we can skip it if
4847 	 * transaction_commit will do it for us.
4848 	 */
4849 	if (sbi->s_journal) {
4850 		target = jbd2_get_latest_transaction(sbi->s_journal);
4851 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4852 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4853 			needs_barrier = true;
4854 
4855 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4856 			if (wait)
4857 				ret = jbd2_log_wait_commit(sbi->s_journal,
4858 							   target);
4859 		}
4860 	} else if (wait && test_opt(sb, BARRIER))
4861 		needs_barrier = true;
4862 	if (needs_barrier) {
4863 		int err;
4864 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4865 		if (!ret)
4866 			ret = err;
4867 	}
4868 
4869 	return ret;
4870 }
4871 
4872 /*
4873  * LVM calls this function before a (read-only) snapshot is created.  This
4874  * gives us a chance to flush the journal completely and mark the fs clean.
4875  *
4876  * Note that only this function cannot bring a filesystem to be in a clean
4877  * state independently. It relies on upper layer to stop all data & metadata
4878  * modifications.
4879  */
4880 static int ext4_freeze(struct super_block *sb)
4881 {
4882 	int error = 0;
4883 	journal_t *journal;
4884 
4885 	if (sb->s_flags & MS_RDONLY)
4886 		return 0;
4887 
4888 	journal = EXT4_SB(sb)->s_journal;
4889 
4890 	if (journal) {
4891 		/* Now we set up the journal barrier. */
4892 		jbd2_journal_lock_updates(journal);
4893 
4894 		/*
4895 		 * Don't clear the needs_recovery flag if we failed to
4896 		 * flush the journal.
4897 		 */
4898 		error = jbd2_journal_flush(journal);
4899 		if (error < 0)
4900 			goto out;
4901 
4902 		/* Journal blocked and flushed, clear needs_recovery flag. */
4903 		ext4_clear_feature_journal_needs_recovery(sb);
4904 	}
4905 
4906 	error = ext4_commit_super(sb, 1);
4907 out:
4908 	if (journal)
4909 		/* we rely on upper layer to stop further updates */
4910 		jbd2_journal_unlock_updates(journal);
4911 	return error;
4912 }
4913 
4914 /*
4915  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4916  * flag here, even though the filesystem is not technically dirty yet.
4917  */
4918 static int ext4_unfreeze(struct super_block *sb)
4919 {
4920 	if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4921 		return 0;
4922 
4923 	if (EXT4_SB(sb)->s_journal) {
4924 		/* Reset the needs_recovery flag before the fs is unlocked. */
4925 		ext4_set_feature_journal_needs_recovery(sb);
4926 	}
4927 
4928 	ext4_commit_super(sb, 1);
4929 	return 0;
4930 }
4931 
4932 /*
4933  * Structure to save mount options for ext4_remount's benefit
4934  */
4935 struct ext4_mount_options {
4936 	unsigned long s_mount_opt;
4937 	unsigned long s_mount_opt2;
4938 	kuid_t s_resuid;
4939 	kgid_t s_resgid;
4940 	unsigned long s_commit_interval;
4941 	u32 s_min_batch_time, s_max_batch_time;
4942 #ifdef CONFIG_QUOTA
4943 	int s_jquota_fmt;
4944 	char *s_qf_names[EXT4_MAXQUOTAS];
4945 #endif
4946 };
4947 
4948 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4949 {
4950 	struct ext4_super_block *es;
4951 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4952 	unsigned long old_sb_flags;
4953 	struct ext4_mount_options old_opts;
4954 	int enable_quota = 0;
4955 	ext4_group_t g;
4956 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4957 	int err = 0;
4958 #ifdef CONFIG_QUOTA
4959 	int i, j;
4960 #endif
4961 	char *orig_data = kstrdup(data, GFP_KERNEL);
4962 
4963 	/* Store the original options */
4964 	old_sb_flags = sb->s_flags;
4965 	old_opts.s_mount_opt = sbi->s_mount_opt;
4966 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4967 	old_opts.s_resuid = sbi->s_resuid;
4968 	old_opts.s_resgid = sbi->s_resgid;
4969 	old_opts.s_commit_interval = sbi->s_commit_interval;
4970 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4971 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4972 #ifdef CONFIG_QUOTA
4973 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4974 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4975 		if (sbi->s_qf_names[i]) {
4976 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4977 							 GFP_KERNEL);
4978 			if (!old_opts.s_qf_names[i]) {
4979 				for (j = 0; j < i; j++)
4980 					kfree(old_opts.s_qf_names[j]);
4981 				kfree(orig_data);
4982 				return -ENOMEM;
4983 			}
4984 		} else
4985 			old_opts.s_qf_names[i] = NULL;
4986 #endif
4987 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4988 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4989 
4990 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4991 		err = -EINVAL;
4992 		goto restore_opts;
4993 	}
4994 
4995 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4996 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4997 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4998 			 "during remount not supported; ignoring");
4999 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
5000 	}
5001 
5002 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
5003 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
5004 			ext4_msg(sb, KERN_ERR, "can't mount with "
5005 				 "both data=journal and delalloc");
5006 			err = -EINVAL;
5007 			goto restore_opts;
5008 		}
5009 		if (test_opt(sb, DIOREAD_NOLOCK)) {
5010 			ext4_msg(sb, KERN_ERR, "can't mount with "
5011 				 "both data=journal and dioread_nolock");
5012 			err = -EINVAL;
5013 			goto restore_opts;
5014 		}
5015 		if (test_opt(sb, DAX)) {
5016 			ext4_msg(sb, KERN_ERR, "can't mount with "
5017 				 "both data=journal and dax");
5018 			err = -EINVAL;
5019 			goto restore_opts;
5020 		}
5021 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
5022 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
5023 			ext4_msg(sb, KERN_ERR, "can't mount with "
5024 				"journal_async_commit in data=ordered mode");
5025 			err = -EINVAL;
5026 			goto restore_opts;
5027 		}
5028 	}
5029 
5030 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_NO_MBCACHE) {
5031 		ext4_msg(sb, KERN_ERR, "can't enable nombcache during remount");
5032 		err = -EINVAL;
5033 		goto restore_opts;
5034 	}
5035 
5036 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
5037 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
5038 			"dax flag with busy inodes while remounting");
5039 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
5040 	}
5041 
5042 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
5043 		ext4_abort(sb, "Abort forced by user");
5044 
5045 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
5046 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
5047 
5048 	es = sbi->s_es;
5049 
5050 	if (sbi->s_journal) {
5051 		ext4_init_journal_params(sb, sbi->s_journal);
5052 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
5053 	}
5054 
5055 	if (*flags & MS_LAZYTIME)
5056 		sb->s_flags |= MS_LAZYTIME;
5057 
5058 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
5059 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
5060 			err = -EROFS;
5061 			goto restore_opts;
5062 		}
5063 
5064 		if (*flags & MS_RDONLY) {
5065 			err = sync_filesystem(sb);
5066 			if (err < 0)
5067 				goto restore_opts;
5068 			err = dquot_suspend(sb, -1);
5069 			if (err < 0)
5070 				goto restore_opts;
5071 
5072 			/*
5073 			 * First of all, the unconditional stuff we have to do
5074 			 * to disable replay of the journal when we next remount
5075 			 */
5076 			sb->s_flags |= MS_RDONLY;
5077 
5078 			/*
5079 			 * OK, test if we are remounting a valid rw partition
5080 			 * readonly, and if so set the rdonly flag and then
5081 			 * mark the partition as valid again.
5082 			 */
5083 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5084 			    (sbi->s_mount_state & EXT4_VALID_FS))
5085 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5086 
5087 			if (sbi->s_journal)
5088 				ext4_mark_recovery_complete(sb, es);
5089 		} else {
5090 			/* Make sure we can mount this feature set readwrite */
5091 			if (ext4_has_feature_readonly(sb) ||
5092 			    !ext4_feature_set_ok(sb, 0)) {
5093 				err = -EROFS;
5094 				goto restore_opts;
5095 			}
5096 			/*
5097 			 * Make sure the group descriptor checksums
5098 			 * are sane.  If they aren't, refuse to remount r/w.
5099 			 */
5100 			for (g = 0; g < sbi->s_groups_count; g++) {
5101 				struct ext4_group_desc *gdp =
5102 					ext4_get_group_desc(sb, g, NULL);
5103 
5104 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5105 					ext4_msg(sb, KERN_ERR,
5106 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5107 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5108 					       le16_to_cpu(gdp->bg_checksum));
5109 					err = -EFSBADCRC;
5110 					goto restore_opts;
5111 				}
5112 			}
5113 
5114 			/*
5115 			 * If we have an unprocessed orphan list hanging
5116 			 * around from a previously readonly bdev mount,
5117 			 * require a full umount/remount for now.
5118 			 */
5119 			if (es->s_last_orphan) {
5120 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5121 				       "remount RDWR because of unprocessed "
5122 				       "orphan inode list.  Please "
5123 				       "umount/remount instead");
5124 				err = -EINVAL;
5125 				goto restore_opts;
5126 			}
5127 
5128 			/*
5129 			 * Mounting a RDONLY partition read-write, so reread
5130 			 * and store the current valid flag.  (It may have
5131 			 * been changed by e2fsck since we originally mounted
5132 			 * the partition.)
5133 			 */
5134 			if (sbi->s_journal)
5135 				ext4_clear_journal_err(sb, es);
5136 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5137 			if (!ext4_setup_super(sb, es, 0))
5138 				sb->s_flags &= ~MS_RDONLY;
5139 			if (ext4_has_feature_mmp(sb))
5140 				if (ext4_multi_mount_protect(sb,
5141 						le64_to_cpu(es->s_mmp_block))) {
5142 					err = -EROFS;
5143 					goto restore_opts;
5144 				}
5145 			enable_quota = 1;
5146 		}
5147 	}
5148 
5149 	/*
5150 	 * Reinitialize lazy itable initialization thread based on
5151 	 * current settings
5152 	 */
5153 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5154 		ext4_unregister_li_request(sb);
5155 	else {
5156 		ext4_group_t first_not_zeroed;
5157 		first_not_zeroed = ext4_has_uninit_itable(sb);
5158 		ext4_register_li_request(sb, first_not_zeroed);
5159 	}
5160 
5161 	ext4_setup_system_zone(sb);
5162 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5163 		ext4_commit_super(sb, 1);
5164 
5165 #ifdef CONFIG_QUOTA
5166 	/* Release old quota file names */
5167 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5168 		kfree(old_opts.s_qf_names[i]);
5169 	if (enable_quota) {
5170 		if (sb_any_quota_suspended(sb))
5171 			dquot_resume(sb, -1);
5172 		else if (ext4_has_feature_quota(sb)) {
5173 			err = ext4_enable_quotas(sb);
5174 			if (err)
5175 				goto restore_opts;
5176 		}
5177 	}
5178 #endif
5179 
5180 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5181 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5182 	kfree(orig_data);
5183 	return 0;
5184 
5185 restore_opts:
5186 	sb->s_flags = old_sb_flags;
5187 	sbi->s_mount_opt = old_opts.s_mount_opt;
5188 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5189 	sbi->s_resuid = old_opts.s_resuid;
5190 	sbi->s_resgid = old_opts.s_resgid;
5191 	sbi->s_commit_interval = old_opts.s_commit_interval;
5192 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5193 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5194 #ifdef CONFIG_QUOTA
5195 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5196 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5197 		kfree(sbi->s_qf_names[i]);
5198 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5199 	}
5200 #endif
5201 	kfree(orig_data);
5202 	return err;
5203 }
5204 
5205 #ifdef CONFIG_QUOTA
5206 static int ext4_statfs_project(struct super_block *sb,
5207 			       kprojid_t projid, struct kstatfs *buf)
5208 {
5209 	struct kqid qid;
5210 	struct dquot *dquot;
5211 	u64 limit;
5212 	u64 curblock;
5213 
5214 	qid = make_kqid_projid(projid);
5215 	dquot = dqget(sb, qid);
5216 	if (IS_ERR(dquot))
5217 		return PTR_ERR(dquot);
5218 	spin_lock(&dquot->dq_dqb_lock);
5219 
5220 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5221 		 dquot->dq_dqb.dqb_bsoftlimit :
5222 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5223 	if (limit && buf->f_blocks > limit) {
5224 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5225 		buf->f_blocks = limit;
5226 		buf->f_bfree = buf->f_bavail =
5227 			(buf->f_blocks > curblock) ?
5228 			 (buf->f_blocks - curblock) : 0;
5229 	}
5230 
5231 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5232 		dquot->dq_dqb.dqb_isoftlimit :
5233 		dquot->dq_dqb.dqb_ihardlimit;
5234 	if (limit && buf->f_files > limit) {
5235 		buf->f_files = limit;
5236 		buf->f_ffree =
5237 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5238 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5239 	}
5240 
5241 	spin_unlock(&dquot->dq_dqb_lock);
5242 	dqput(dquot);
5243 	return 0;
5244 }
5245 #endif
5246 
5247 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5248 {
5249 	struct super_block *sb = dentry->d_sb;
5250 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5251 	struct ext4_super_block *es = sbi->s_es;
5252 	ext4_fsblk_t overhead = 0, resv_blocks;
5253 	u64 fsid;
5254 	s64 bfree;
5255 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5256 
5257 	if (!test_opt(sb, MINIX_DF))
5258 		overhead = sbi->s_overhead;
5259 
5260 	buf->f_type = EXT4_SUPER_MAGIC;
5261 	buf->f_bsize = sb->s_blocksize;
5262 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5263 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5264 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5265 	/* prevent underflow in case that few free space is available */
5266 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5267 	buf->f_bavail = buf->f_bfree -
5268 			(ext4_r_blocks_count(es) + resv_blocks);
5269 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5270 		buf->f_bavail = 0;
5271 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5272 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5273 	buf->f_namelen = EXT4_NAME_LEN;
5274 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5275 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5276 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5277 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5278 
5279 #ifdef CONFIG_QUOTA
5280 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5281 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5282 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5283 #endif
5284 	return 0;
5285 }
5286 
5287 
5288 #ifdef CONFIG_QUOTA
5289 
5290 /*
5291  * Helper functions so that transaction is started before we acquire dqio_sem
5292  * to keep correct lock ordering of transaction > dqio_sem
5293  */
5294 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5295 {
5296 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5297 }
5298 
5299 static int ext4_write_dquot(struct dquot *dquot)
5300 {
5301 	int ret, err;
5302 	handle_t *handle;
5303 	struct inode *inode;
5304 
5305 	inode = dquot_to_inode(dquot);
5306 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5307 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5308 	if (IS_ERR(handle))
5309 		return PTR_ERR(handle);
5310 	ret = dquot_commit(dquot);
5311 	err = ext4_journal_stop(handle);
5312 	if (!ret)
5313 		ret = err;
5314 	return ret;
5315 }
5316 
5317 static int ext4_acquire_dquot(struct dquot *dquot)
5318 {
5319 	int ret, err;
5320 	handle_t *handle;
5321 
5322 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5323 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5324 	if (IS_ERR(handle))
5325 		return PTR_ERR(handle);
5326 	ret = dquot_acquire(dquot);
5327 	err = ext4_journal_stop(handle);
5328 	if (!ret)
5329 		ret = err;
5330 	return ret;
5331 }
5332 
5333 static int ext4_release_dquot(struct dquot *dquot)
5334 {
5335 	int ret, err;
5336 	handle_t *handle;
5337 
5338 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5339 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5340 	if (IS_ERR(handle)) {
5341 		/* Release dquot anyway to avoid endless cycle in dqput() */
5342 		dquot_release(dquot);
5343 		return PTR_ERR(handle);
5344 	}
5345 	ret = dquot_release(dquot);
5346 	err = ext4_journal_stop(handle);
5347 	if (!ret)
5348 		ret = err;
5349 	return ret;
5350 }
5351 
5352 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5353 {
5354 	struct super_block *sb = dquot->dq_sb;
5355 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5356 
5357 	/* Are we journaling quotas? */
5358 	if (ext4_has_feature_quota(sb) ||
5359 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5360 		dquot_mark_dquot_dirty(dquot);
5361 		return ext4_write_dquot(dquot);
5362 	} else {
5363 		return dquot_mark_dquot_dirty(dquot);
5364 	}
5365 }
5366 
5367 static int ext4_write_info(struct super_block *sb, int type)
5368 {
5369 	int ret, err;
5370 	handle_t *handle;
5371 
5372 	/* Data block + inode block */
5373 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5374 	if (IS_ERR(handle))
5375 		return PTR_ERR(handle);
5376 	ret = dquot_commit_info(sb, type);
5377 	err = ext4_journal_stop(handle);
5378 	if (!ret)
5379 		ret = err;
5380 	return ret;
5381 }
5382 
5383 /*
5384  * Turn on quotas during mount time - we need to find
5385  * the quota file and such...
5386  */
5387 static int ext4_quota_on_mount(struct super_block *sb, int type)
5388 {
5389 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5390 					EXT4_SB(sb)->s_jquota_fmt, type);
5391 }
5392 
5393 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5394 {
5395 	struct ext4_inode_info *ei = EXT4_I(inode);
5396 
5397 	/* The first argument of lockdep_set_subclass has to be
5398 	 * *exactly* the same as the argument to init_rwsem() --- in
5399 	 * this case, in init_once() --- or lockdep gets unhappy
5400 	 * because the name of the lock is set using the
5401 	 * stringification of the argument to init_rwsem().
5402 	 */
5403 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5404 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5405 }
5406 
5407 /*
5408  * Standard function to be called on quota_on
5409  */
5410 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5411 			 const struct path *path)
5412 {
5413 	int err;
5414 
5415 	if (!test_opt(sb, QUOTA))
5416 		return -EINVAL;
5417 
5418 	/* Quotafile not on the same filesystem? */
5419 	if (path->dentry->d_sb != sb)
5420 		return -EXDEV;
5421 	/* Journaling quota? */
5422 	if (EXT4_SB(sb)->s_qf_names[type]) {
5423 		/* Quotafile not in fs root? */
5424 		if (path->dentry->d_parent != sb->s_root)
5425 			ext4_msg(sb, KERN_WARNING,
5426 				"Quota file not on filesystem root. "
5427 				"Journaled quota will not work");
5428 		sb_dqopt(sb)->flags |= DQUOT_NOLIST_DIRTY;
5429 	} else {
5430 		/*
5431 		 * Clear the flag just in case mount options changed since
5432 		 * last time.
5433 		 */
5434 		sb_dqopt(sb)->flags &= ~DQUOT_NOLIST_DIRTY;
5435 	}
5436 
5437 	/*
5438 	 * When we journal data on quota file, we have to flush journal to see
5439 	 * all updates to the file when we bypass pagecache...
5440 	 */
5441 	if (EXT4_SB(sb)->s_journal &&
5442 	    ext4_should_journal_data(d_inode(path->dentry))) {
5443 		/*
5444 		 * We don't need to lock updates but journal_flush() could
5445 		 * otherwise be livelocked...
5446 		 */
5447 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5448 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5449 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5450 		if (err)
5451 			return err;
5452 	}
5453 
5454 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5455 	err = dquot_quota_on(sb, type, format_id, path);
5456 	if (err) {
5457 		lockdep_set_quota_inode(path->dentry->d_inode,
5458 					     I_DATA_SEM_NORMAL);
5459 	} else {
5460 		struct inode *inode = d_inode(path->dentry);
5461 		handle_t *handle;
5462 
5463 		/*
5464 		 * Set inode flags to prevent userspace from messing with quota
5465 		 * files. If this fails, we return success anyway since quotas
5466 		 * are already enabled and this is not a hard failure.
5467 		 */
5468 		inode_lock(inode);
5469 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5470 		if (IS_ERR(handle))
5471 			goto unlock_inode;
5472 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5473 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5474 				S_NOATIME | S_IMMUTABLE);
5475 		ext4_mark_inode_dirty(handle, inode);
5476 		ext4_journal_stop(handle);
5477 	unlock_inode:
5478 		inode_unlock(inode);
5479 	}
5480 	return err;
5481 }
5482 
5483 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5484 			     unsigned int flags)
5485 {
5486 	int err;
5487 	struct inode *qf_inode;
5488 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5489 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5490 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5491 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5492 	};
5493 
5494 	BUG_ON(!ext4_has_feature_quota(sb));
5495 
5496 	if (!qf_inums[type])
5497 		return -EPERM;
5498 
5499 	qf_inode = ext4_iget(sb, qf_inums[type]);
5500 	if (IS_ERR(qf_inode)) {
5501 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5502 		return PTR_ERR(qf_inode);
5503 	}
5504 
5505 	/* Don't account quota for quota files to avoid recursion */
5506 	qf_inode->i_flags |= S_NOQUOTA;
5507 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5508 	err = dquot_enable(qf_inode, type, format_id, flags);
5509 	iput(qf_inode);
5510 	if (err)
5511 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5512 
5513 	return err;
5514 }
5515 
5516 /* Enable usage tracking for all quota types. */
5517 static int ext4_enable_quotas(struct super_block *sb)
5518 {
5519 	int type, err = 0;
5520 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5521 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5522 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5523 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5524 	};
5525 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5526 		test_opt(sb, USRQUOTA),
5527 		test_opt(sb, GRPQUOTA),
5528 		test_opt(sb, PRJQUOTA),
5529 	};
5530 
5531 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
5532 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5533 		if (qf_inums[type]) {
5534 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5535 				DQUOT_USAGE_ENABLED |
5536 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5537 			if (err) {
5538 				for (type--; type >= 0; type--)
5539 					dquot_quota_off(sb, type);
5540 
5541 				ext4_warning(sb,
5542 					"Failed to enable quota tracking "
5543 					"(type=%d, err=%d). Please run "
5544 					"e2fsck to fix.", type, err);
5545 				return err;
5546 			}
5547 		}
5548 	}
5549 	return 0;
5550 }
5551 
5552 static int ext4_quota_off(struct super_block *sb, int type)
5553 {
5554 	struct inode *inode = sb_dqopt(sb)->files[type];
5555 	handle_t *handle;
5556 	int err;
5557 
5558 	/* Force all delayed allocation blocks to be allocated.
5559 	 * Caller already holds s_umount sem */
5560 	if (test_opt(sb, DELALLOC))
5561 		sync_filesystem(sb);
5562 
5563 	if (!inode || !igrab(inode))
5564 		goto out;
5565 
5566 	err = dquot_quota_off(sb, type);
5567 	if (err || ext4_has_feature_quota(sb))
5568 		goto out_put;
5569 
5570 	inode_lock(inode);
5571 	/*
5572 	 * Update modification times of quota files when userspace can
5573 	 * start looking at them. If we fail, we return success anyway since
5574 	 * this is not a hard failure and quotas are already disabled.
5575 	 */
5576 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5577 	if (IS_ERR(handle))
5578 		goto out_unlock;
5579 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5580 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5581 	inode->i_mtime = inode->i_ctime = current_time(inode);
5582 	ext4_mark_inode_dirty(handle, inode);
5583 	ext4_journal_stop(handle);
5584 out_unlock:
5585 	inode_unlock(inode);
5586 out_put:
5587 	lockdep_set_quota_inode(inode, I_DATA_SEM_NORMAL);
5588 	iput(inode);
5589 	return err;
5590 out:
5591 	return dquot_quota_off(sb, type);
5592 }
5593 
5594 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5595  * acquiring the locks... As quota files are never truncated and quota code
5596  * itself serializes the operations (and no one else should touch the files)
5597  * we don't have to be afraid of races */
5598 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5599 			       size_t len, loff_t off)
5600 {
5601 	struct inode *inode = sb_dqopt(sb)->files[type];
5602 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5603 	int offset = off & (sb->s_blocksize - 1);
5604 	int tocopy;
5605 	size_t toread;
5606 	struct buffer_head *bh;
5607 	loff_t i_size = i_size_read(inode);
5608 
5609 	if (off > i_size)
5610 		return 0;
5611 	if (off+len > i_size)
5612 		len = i_size-off;
5613 	toread = len;
5614 	while (toread > 0) {
5615 		tocopy = sb->s_blocksize - offset < toread ?
5616 				sb->s_blocksize - offset : toread;
5617 		bh = ext4_bread(NULL, inode, blk, 0);
5618 		if (IS_ERR(bh))
5619 			return PTR_ERR(bh);
5620 		if (!bh)	/* A hole? */
5621 			memset(data, 0, tocopy);
5622 		else
5623 			memcpy(data, bh->b_data+offset, tocopy);
5624 		brelse(bh);
5625 		offset = 0;
5626 		toread -= tocopy;
5627 		data += tocopy;
5628 		blk++;
5629 	}
5630 	return len;
5631 }
5632 
5633 /* Write to quotafile (we know the transaction is already started and has
5634  * enough credits) */
5635 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5636 				const char *data, size_t len, loff_t off)
5637 {
5638 	struct inode *inode = sb_dqopt(sb)->files[type];
5639 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5640 	int err, offset = off & (sb->s_blocksize - 1);
5641 	int retries = 0;
5642 	struct buffer_head *bh;
5643 	handle_t *handle = journal_current_handle();
5644 
5645 	if (EXT4_SB(sb)->s_journal && !handle) {
5646 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5647 			" cancelled because transaction is not started",
5648 			(unsigned long long)off, (unsigned long long)len);
5649 		return -EIO;
5650 	}
5651 	/*
5652 	 * Since we account only one data block in transaction credits,
5653 	 * then it is impossible to cross a block boundary.
5654 	 */
5655 	if (sb->s_blocksize - offset < len) {
5656 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5657 			" cancelled because not block aligned",
5658 			(unsigned long long)off, (unsigned long long)len);
5659 		return -EIO;
5660 	}
5661 
5662 	do {
5663 		bh = ext4_bread(handle, inode, blk,
5664 				EXT4_GET_BLOCKS_CREATE |
5665 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5666 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5667 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5668 	if (IS_ERR(bh))
5669 		return PTR_ERR(bh);
5670 	if (!bh)
5671 		goto out;
5672 	BUFFER_TRACE(bh, "get write access");
5673 	err = ext4_journal_get_write_access(handle, bh);
5674 	if (err) {
5675 		brelse(bh);
5676 		return err;
5677 	}
5678 	lock_buffer(bh);
5679 	memcpy(bh->b_data+offset, data, len);
5680 	flush_dcache_page(bh->b_page);
5681 	unlock_buffer(bh);
5682 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5683 	brelse(bh);
5684 out:
5685 	if (inode->i_size < off + len) {
5686 		i_size_write(inode, off + len);
5687 		EXT4_I(inode)->i_disksize = inode->i_size;
5688 		ext4_mark_inode_dirty(handle, inode);
5689 	}
5690 	return len;
5691 }
5692 
5693 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5694 {
5695 	const struct quota_format_ops	*ops;
5696 
5697 	if (!sb_has_quota_loaded(sb, qid->type))
5698 		return -ESRCH;
5699 	ops = sb_dqopt(sb)->ops[qid->type];
5700 	if (!ops || !ops->get_next_id)
5701 		return -ENOSYS;
5702 	return dquot_get_next_id(sb, qid);
5703 }
5704 #endif
5705 
5706 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5707 		       const char *dev_name, void *data)
5708 {
5709 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5710 }
5711 
5712 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5713 static inline void register_as_ext2(void)
5714 {
5715 	int err = register_filesystem(&ext2_fs_type);
5716 	if (err)
5717 		printk(KERN_WARNING
5718 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5719 }
5720 
5721 static inline void unregister_as_ext2(void)
5722 {
5723 	unregister_filesystem(&ext2_fs_type);
5724 }
5725 
5726 static inline int ext2_feature_set_ok(struct super_block *sb)
5727 {
5728 	if (ext4_has_unknown_ext2_incompat_features(sb))
5729 		return 0;
5730 	if (sb->s_flags & MS_RDONLY)
5731 		return 1;
5732 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5733 		return 0;
5734 	return 1;
5735 }
5736 #else
5737 static inline void register_as_ext2(void) { }
5738 static inline void unregister_as_ext2(void) { }
5739 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5740 #endif
5741 
5742 static inline void register_as_ext3(void)
5743 {
5744 	int err = register_filesystem(&ext3_fs_type);
5745 	if (err)
5746 		printk(KERN_WARNING
5747 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5748 }
5749 
5750 static inline void unregister_as_ext3(void)
5751 {
5752 	unregister_filesystem(&ext3_fs_type);
5753 }
5754 
5755 static inline int ext3_feature_set_ok(struct super_block *sb)
5756 {
5757 	if (ext4_has_unknown_ext3_incompat_features(sb))
5758 		return 0;
5759 	if (!ext4_has_feature_journal(sb))
5760 		return 0;
5761 	if (sb->s_flags & MS_RDONLY)
5762 		return 1;
5763 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5764 		return 0;
5765 	return 1;
5766 }
5767 
5768 static struct file_system_type ext4_fs_type = {
5769 	.owner		= THIS_MODULE,
5770 	.name		= "ext4",
5771 	.mount		= ext4_mount,
5772 	.kill_sb	= kill_block_super,
5773 	.fs_flags	= FS_REQUIRES_DEV,
5774 };
5775 MODULE_ALIAS_FS("ext4");
5776 
5777 /* Shared across all ext4 file systems */
5778 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5779 
5780 static int __init ext4_init_fs(void)
5781 {
5782 	int i, err;
5783 
5784 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5785 	ext4_li_info = NULL;
5786 	mutex_init(&ext4_li_mtx);
5787 
5788 	/* Build-time check for flags consistency */
5789 	ext4_check_flag_values();
5790 
5791 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5792 		init_waitqueue_head(&ext4__ioend_wq[i]);
5793 
5794 	err = ext4_init_es();
5795 	if (err)
5796 		return err;
5797 
5798 	err = ext4_init_pageio();
5799 	if (err)
5800 		goto out5;
5801 
5802 	err = ext4_init_system_zone();
5803 	if (err)
5804 		goto out4;
5805 
5806 	err = ext4_init_sysfs();
5807 	if (err)
5808 		goto out3;
5809 
5810 	err = ext4_init_mballoc();
5811 	if (err)
5812 		goto out2;
5813 	err = init_inodecache();
5814 	if (err)
5815 		goto out1;
5816 	register_as_ext3();
5817 	register_as_ext2();
5818 	err = register_filesystem(&ext4_fs_type);
5819 	if (err)
5820 		goto out;
5821 
5822 	return 0;
5823 out:
5824 	unregister_as_ext2();
5825 	unregister_as_ext3();
5826 	destroy_inodecache();
5827 out1:
5828 	ext4_exit_mballoc();
5829 out2:
5830 	ext4_exit_sysfs();
5831 out3:
5832 	ext4_exit_system_zone();
5833 out4:
5834 	ext4_exit_pageio();
5835 out5:
5836 	ext4_exit_es();
5837 
5838 	return err;
5839 }
5840 
5841 static void __exit ext4_exit_fs(void)
5842 {
5843 	ext4_destroy_lazyinit_thread();
5844 	unregister_as_ext2();
5845 	unregister_as_ext3();
5846 	unregister_filesystem(&ext4_fs_type);
5847 	destroy_inodecache();
5848 	ext4_exit_mballoc();
5849 	ext4_exit_sysfs();
5850 	ext4_exit_system_zone();
5851 	ext4_exit_pageio();
5852 	ext4_exit_es();
5853 }
5854 
5855 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5856 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5857 MODULE_LICENSE("GPL");
5858 module_init(ext4_init_fs)
5859 module_exit(ext4_exit_fs)
5860