xref: /linux/fs/ext4/super.c (revision 05384213436ab690c46d9dfec706b80ef8d671ab)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/slab.h>
25 #include <linux/init.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/ctype.h>
38 #include <linux/log2.h>
39 #include <linux/crc16.h>
40 #include <linux/cleancache.h>
41 #include <linux/uaccess.h>
42 
43 #include <linux/kthread.h>
44 #include <linux/freezer.h>
45 
46 #include "ext4.h"
47 #include "ext4_extents.h"	/* Needed for trace points definition */
48 #include "ext4_jbd2.h"
49 #include "xattr.h"
50 #include "acl.h"
51 #include "mballoc.h"
52 #include "fsmap.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct ext4_lazy_init *ext4_li_info;
58 static struct mutex ext4_li_mtx;
59 static struct ratelimit_state ext4_mount_msg_ratelimit;
60 
61 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
62 			     unsigned long journal_devnum);
63 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
64 static int ext4_commit_super(struct super_block *sb, int sync);
65 static void ext4_mark_recovery_complete(struct super_block *sb,
66 					struct ext4_super_block *es);
67 static void ext4_clear_journal_err(struct super_block *sb,
68 				   struct ext4_super_block *es);
69 static int ext4_sync_fs(struct super_block *sb, int wait);
70 static int ext4_remount(struct super_block *sb, int *flags, char *data);
71 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
72 static int ext4_unfreeze(struct super_block *sb);
73 static int ext4_freeze(struct super_block *sb);
74 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
75 		       const char *dev_name, void *data);
76 static inline int ext2_feature_set_ok(struct super_block *sb);
77 static inline int ext3_feature_set_ok(struct super_block *sb);
78 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
79 static void ext4_destroy_lazyinit_thread(void);
80 static void ext4_unregister_li_request(struct super_block *sb);
81 static void ext4_clear_request_list(void);
82 static struct inode *ext4_get_journal_inode(struct super_block *sb,
83 					    unsigned int journal_inum);
84 
85 /*
86  * Lock ordering
87  *
88  * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
89  * i_mmap_rwsem (inode->i_mmap_rwsem)!
90  *
91  * page fault path:
92  * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
93  *   page lock -> i_data_sem (rw)
94  *
95  * buffered write path:
96  * sb_start_write -> i_mutex -> mmap_sem
97  * sb_start_write -> i_mutex -> transaction start -> page lock ->
98  *   i_data_sem (rw)
99  *
100  * truncate:
101  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
102  *   i_mmap_rwsem (w) -> page lock
103  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
104  *   transaction start -> i_data_sem (rw)
105  *
106  * direct IO:
107  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
108  * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
109  *   transaction start -> i_data_sem (rw)
110  *
111  * writepages:
112  * transaction start -> page lock(s) -> i_data_sem (rw)
113  */
114 
115 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
116 static struct file_system_type ext2_fs_type = {
117 	.owner		= THIS_MODULE,
118 	.name		= "ext2",
119 	.mount		= ext4_mount,
120 	.kill_sb	= kill_block_super,
121 	.fs_flags	= FS_REQUIRES_DEV,
122 };
123 MODULE_ALIAS_FS("ext2");
124 MODULE_ALIAS("ext2");
125 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
126 #else
127 #define IS_EXT2_SB(sb) (0)
128 #endif
129 
130 
131 static struct file_system_type ext3_fs_type = {
132 	.owner		= THIS_MODULE,
133 	.name		= "ext3",
134 	.mount		= ext4_mount,
135 	.kill_sb	= kill_block_super,
136 	.fs_flags	= FS_REQUIRES_DEV,
137 };
138 MODULE_ALIAS_FS("ext3");
139 MODULE_ALIAS("ext3");
140 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
141 
142 static int ext4_verify_csum_type(struct super_block *sb,
143 				 struct ext4_super_block *es)
144 {
145 	if (!ext4_has_feature_metadata_csum(sb))
146 		return 1;
147 
148 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
149 }
150 
151 static __le32 ext4_superblock_csum(struct super_block *sb,
152 				   struct ext4_super_block *es)
153 {
154 	struct ext4_sb_info *sbi = EXT4_SB(sb);
155 	int offset = offsetof(struct ext4_super_block, s_checksum);
156 	__u32 csum;
157 
158 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
159 
160 	return cpu_to_le32(csum);
161 }
162 
163 static int ext4_superblock_csum_verify(struct super_block *sb,
164 				       struct ext4_super_block *es)
165 {
166 	if (!ext4_has_metadata_csum(sb))
167 		return 1;
168 
169 	return es->s_checksum == ext4_superblock_csum(sb, es);
170 }
171 
172 void ext4_superblock_csum_set(struct super_block *sb)
173 {
174 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
175 
176 	if (!ext4_has_metadata_csum(sb))
177 		return;
178 
179 	es->s_checksum = ext4_superblock_csum(sb, es);
180 }
181 
182 void *ext4_kvmalloc(size_t size, gfp_t flags)
183 {
184 	void *ret;
185 
186 	ret = kmalloc(size, flags | __GFP_NOWARN);
187 	if (!ret)
188 		ret = __vmalloc(size, flags, PAGE_KERNEL);
189 	return ret;
190 }
191 
192 void *ext4_kvzalloc(size_t size, gfp_t flags)
193 {
194 	void *ret;
195 
196 	ret = kzalloc(size, flags | __GFP_NOWARN);
197 	if (!ret)
198 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
199 	return ret;
200 }
201 
202 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
203 			       struct ext4_group_desc *bg)
204 {
205 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
206 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
207 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
208 }
209 
210 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
211 			       struct ext4_group_desc *bg)
212 {
213 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
214 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
215 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
216 }
217 
218 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
219 			      struct ext4_group_desc *bg)
220 {
221 	return le32_to_cpu(bg->bg_inode_table_lo) |
222 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
223 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
224 }
225 
226 __u32 ext4_free_group_clusters(struct super_block *sb,
227 			       struct ext4_group_desc *bg)
228 {
229 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
230 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
231 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
232 }
233 
234 __u32 ext4_free_inodes_count(struct super_block *sb,
235 			      struct ext4_group_desc *bg)
236 {
237 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
238 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
239 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
240 }
241 
242 __u32 ext4_used_dirs_count(struct super_block *sb,
243 			      struct ext4_group_desc *bg)
244 {
245 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
246 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
247 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
248 }
249 
250 __u32 ext4_itable_unused_count(struct super_block *sb,
251 			      struct ext4_group_desc *bg)
252 {
253 	return le16_to_cpu(bg->bg_itable_unused_lo) |
254 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
255 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
256 }
257 
258 void ext4_block_bitmap_set(struct super_block *sb,
259 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
260 {
261 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
262 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
263 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
264 }
265 
266 void ext4_inode_bitmap_set(struct super_block *sb,
267 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
268 {
269 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
270 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
271 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
272 }
273 
274 void ext4_inode_table_set(struct super_block *sb,
275 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
276 {
277 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
278 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
279 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
280 }
281 
282 void ext4_free_group_clusters_set(struct super_block *sb,
283 				  struct ext4_group_desc *bg, __u32 count)
284 {
285 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
286 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
287 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
288 }
289 
290 void ext4_free_inodes_set(struct super_block *sb,
291 			  struct ext4_group_desc *bg, __u32 count)
292 {
293 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
294 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
295 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
296 }
297 
298 void ext4_used_dirs_set(struct super_block *sb,
299 			  struct ext4_group_desc *bg, __u32 count)
300 {
301 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
302 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
303 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
304 }
305 
306 void ext4_itable_unused_set(struct super_block *sb,
307 			  struct ext4_group_desc *bg, __u32 count)
308 {
309 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
310 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
311 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
312 }
313 
314 
315 static void __save_error_info(struct super_block *sb, const char *func,
316 			    unsigned int line)
317 {
318 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
319 
320 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
321 	if (bdev_read_only(sb->s_bdev))
322 		return;
323 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
324 	es->s_last_error_time = cpu_to_le32(get_seconds());
325 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
326 	es->s_last_error_line = cpu_to_le32(line);
327 	if (!es->s_first_error_time) {
328 		es->s_first_error_time = es->s_last_error_time;
329 		strncpy(es->s_first_error_func, func,
330 			sizeof(es->s_first_error_func));
331 		es->s_first_error_line = cpu_to_le32(line);
332 		es->s_first_error_ino = es->s_last_error_ino;
333 		es->s_first_error_block = es->s_last_error_block;
334 	}
335 	/*
336 	 * Start the daily error reporting function if it hasn't been
337 	 * started already
338 	 */
339 	if (!es->s_error_count)
340 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
341 	le32_add_cpu(&es->s_error_count, 1);
342 }
343 
344 static void save_error_info(struct super_block *sb, const char *func,
345 			    unsigned int line)
346 {
347 	__save_error_info(sb, func, line);
348 	ext4_commit_super(sb, 1);
349 }
350 
351 /*
352  * The del_gendisk() function uninitializes the disk-specific data
353  * structures, including the bdi structure, without telling anyone
354  * else.  Once this happens, any attempt to call mark_buffer_dirty()
355  * (for example, by ext4_commit_super), will cause a kernel OOPS.
356  * This is a kludge to prevent these oops until we can put in a proper
357  * hook in del_gendisk() to inform the VFS and file system layers.
358  */
359 static int block_device_ejected(struct super_block *sb)
360 {
361 	struct inode *bd_inode = sb->s_bdev->bd_inode;
362 	struct backing_dev_info *bdi = inode_to_bdi(bd_inode);
363 
364 	return bdi->dev == NULL;
365 }
366 
367 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
368 {
369 	struct super_block		*sb = journal->j_private;
370 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
371 	int				error = is_journal_aborted(journal);
372 	struct ext4_journal_cb_entry	*jce;
373 
374 	BUG_ON(txn->t_state == T_FINISHED);
375 	spin_lock(&sbi->s_md_lock);
376 	while (!list_empty(&txn->t_private_list)) {
377 		jce = list_entry(txn->t_private_list.next,
378 				 struct ext4_journal_cb_entry, jce_list);
379 		list_del_init(&jce->jce_list);
380 		spin_unlock(&sbi->s_md_lock);
381 		jce->jce_func(sb, jce, error);
382 		spin_lock(&sbi->s_md_lock);
383 	}
384 	spin_unlock(&sbi->s_md_lock);
385 }
386 
387 /* Deal with the reporting of failure conditions on a filesystem such as
388  * inconsistencies detected or read IO failures.
389  *
390  * On ext2, we can store the error state of the filesystem in the
391  * superblock.  That is not possible on ext4, because we may have other
392  * write ordering constraints on the superblock which prevent us from
393  * writing it out straight away; and given that the journal is about to
394  * be aborted, we can't rely on the current, or future, transactions to
395  * write out the superblock safely.
396  *
397  * We'll just use the jbd2_journal_abort() error code to record an error in
398  * the journal instead.  On recovery, the journal will complain about
399  * that error until we've noted it down and cleared it.
400  */
401 
402 static void ext4_handle_error(struct super_block *sb)
403 {
404 	if (sb->s_flags & MS_RDONLY)
405 		return;
406 
407 	if (!test_opt(sb, ERRORS_CONT)) {
408 		journal_t *journal = EXT4_SB(sb)->s_journal;
409 
410 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
411 		if (journal)
412 			jbd2_journal_abort(journal, -EIO);
413 	}
414 	if (test_opt(sb, ERRORS_RO)) {
415 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
416 		/*
417 		 * Make sure updated value of ->s_mount_flags will be visible
418 		 * before ->s_flags update
419 		 */
420 		smp_wmb();
421 		sb->s_flags |= MS_RDONLY;
422 	}
423 	if (test_opt(sb, ERRORS_PANIC)) {
424 		if (EXT4_SB(sb)->s_journal &&
425 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
426 			return;
427 		panic("EXT4-fs (device %s): panic forced after error\n",
428 			sb->s_id);
429 	}
430 }
431 
432 #define ext4_error_ratelimit(sb)					\
433 		___ratelimit(&(EXT4_SB(sb)->s_err_ratelimit_state),	\
434 			     "EXT4-fs error")
435 
436 void __ext4_error(struct super_block *sb, const char *function,
437 		  unsigned int line, const char *fmt, ...)
438 {
439 	struct va_format vaf;
440 	va_list args;
441 
442 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
443 		return;
444 
445 	if (ext4_error_ratelimit(sb)) {
446 		va_start(args, fmt);
447 		vaf.fmt = fmt;
448 		vaf.va = &args;
449 		printk(KERN_CRIT
450 		       "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
451 		       sb->s_id, function, line, current->comm, &vaf);
452 		va_end(args);
453 	}
454 	save_error_info(sb, function, line);
455 	ext4_handle_error(sb);
456 }
457 
458 void __ext4_error_inode(struct inode *inode, const char *function,
459 			unsigned int line, ext4_fsblk_t block,
460 			const char *fmt, ...)
461 {
462 	va_list args;
463 	struct va_format vaf;
464 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
465 
466 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
467 		return;
468 
469 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
470 	es->s_last_error_block = cpu_to_le64(block);
471 	if (ext4_error_ratelimit(inode->i_sb)) {
472 		va_start(args, fmt);
473 		vaf.fmt = fmt;
474 		vaf.va = &args;
475 		if (block)
476 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
477 			       "inode #%lu: block %llu: comm %s: %pV\n",
478 			       inode->i_sb->s_id, function, line, inode->i_ino,
479 			       block, current->comm, &vaf);
480 		else
481 			printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
482 			       "inode #%lu: comm %s: %pV\n",
483 			       inode->i_sb->s_id, function, line, inode->i_ino,
484 			       current->comm, &vaf);
485 		va_end(args);
486 	}
487 	save_error_info(inode->i_sb, function, line);
488 	ext4_handle_error(inode->i_sb);
489 }
490 
491 void __ext4_error_file(struct file *file, const char *function,
492 		       unsigned int line, ext4_fsblk_t block,
493 		       const char *fmt, ...)
494 {
495 	va_list args;
496 	struct va_format vaf;
497 	struct ext4_super_block *es;
498 	struct inode *inode = file_inode(file);
499 	char pathname[80], *path;
500 
501 	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
502 		return;
503 
504 	es = EXT4_SB(inode->i_sb)->s_es;
505 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
506 	if (ext4_error_ratelimit(inode->i_sb)) {
507 		path = file_path(file, pathname, sizeof(pathname));
508 		if (IS_ERR(path))
509 			path = "(unknown)";
510 		va_start(args, fmt);
511 		vaf.fmt = fmt;
512 		vaf.va = &args;
513 		if (block)
514 			printk(KERN_CRIT
515 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
516 			       "block %llu: comm %s: path %s: %pV\n",
517 			       inode->i_sb->s_id, function, line, inode->i_ino,
518 			       block, current->comm, path, &vaf);
519 		else
520 			printk(KERN_CRIT
521 			       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
522 			       "comm %s: path %s: %pV\n",
523 			       inode->i_sb->s_id, function, line, inode->i_ino,
524 			       current->comm, path, &vaf);
525 		va_end(args);
526 	}
527 	save_error_info(inode->i_sb, function, line);
528 	ext4_handle_error(inode->i_sb);
529 }
530 
531 const char *ext4_decode_error(struct super_block *sb, int errno,
532 			      char nbuf[16])
533 {
534 	char *errstr = NULL;
535 
536 	switch (errno) {
537 	case -EFSCORRUPTED:
538 		errstr = "Corrupt filesystem";
539 		break;
540 	case -EFSBADCRC:
541 		errstr = "Filesystem failed CRC";
542 		break;
543 	case -EIO:
544 		errstr = "IO failure";
545 		break;
546 	case -ENOMEM:
547 		errstr = "Out of memory";
548 		break;
549 	case -EROFS:
550 		if (!sb || (EXT4_SB(sb)->s_journal &&
551 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
552 			errstr = "Journal has aborted";
553 		else
554 			errstr = "Readonly filesystem";
555 		break;
556 	default:
557 		/* If the caller passed in an extra buffer for unknown
558 		 * errors, textualise them now.  Else we just return
559 		 * NULL. */
560 		if (nbuf) {
561 			/* Check for truncated error codes... */
562 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
563 				errstr = nbuf;
564 		}
565 		break;
566 	}
567 
568 	return errstr;
569 }
570 
571 /* __ext4_std_error decodes expected errors from journaling functions
572  * automatically and invokes the appropriate error response.  */
573 
574 void __ext4_std_error(struct super_block *sb, const char *function,
575 		      unsigned int line, int errno)
576 {
577 	char nbuf[16];
578 	const char *errstr;
579 
580 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
581 		return;
582 
583 	/* Special case: if the error is EROFS, and we're not already
584 	 * inside a transaction, then there's really no point in logging
585 	 * an error. */
586 	if (errno == -EROFS && journal_current_handle() == NULL &&
587 	    (sb->s_flags & MS_RDONLY))
588 		return;
589 
590 	if (ext4_error_ratelimit(sb)) {
591 		errstr = ext4_decode_error(sb, errno, nbuf);
592 		printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
593 		       sb->s_id, function, line, errstr);
594 	}
595 
596 	save_error_info(sb, function, line);
597 	ext4_handle_error(sb);
598 }
599 
600 /*
601  * ext4_abort is a much stronger failure handler than ext4_error.  The
602  * abort function may be used to deal with unrecoverable failures such
603  * as journal IO errors or ENOMEM at a critical moment in log management.
604  *
605  * We unconditionally force the filesystem into an ABORT|READONLY state,
606  * unless the error response on the fs has been set to panic in which
607  * case we take the easy way out and panic immediately.
608  */
609 
610 void __ext4_abort(struct super_block *sb, const char *function,
611 		unsigned int line, const char *fmt, ...)
612 {
613 	struct va_format vaf;
614 	va_list args;
615 
616 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
617 		return;
618 
619 	save_error_info(sb, function, line);
620 	va_start(args, fmt);
621 	vaf.fmt = fmt;
622 	vaf.va = &args;
623 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: %pV\n",
624 	       sb->s_id, function, line, &vaf);
625 	va_end(args);
626 
627 	if ((sb->s_flags & MS_RDONLY) == 0) {
628 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
629 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
630 		/*
631 		 * Make sure updated value of ->s_mount_flags will be visible
632 		 * before ->s_flags update
633 		 */
634 		smp_wmb();
635 		sb->s_flags |= MS_RDONLY;
636 		if (EXT4_SB(sb)->s_journal)
637 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
638 		save_error_info(sb, function, line);
639 	}
640 	if (test_opt(sb, ERRORS_PANIC)) {
641 		if (EXT4_SB(sb)->s_journal &&
642 		  !(EXT4_SB(sb)->s_journal->j_flags & JBD2_REC_ERR))
643 			return;
644 		panic("EXT4-fs panic from previous error\n");
645 	}
646 }
647 
648 void __ext4_msg(struct super_block *sb,
649 		const char *prefix, const char *fmt, ...)
650 {
651 	struct va_format vaf;
652 	va_list args;
653 
654 	if (!___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state), "EXT4-fs"))
655 		return;
656 
657 	va_start(args, fmt);
658 	vaf.fmt = fmt;
659 	vaf.va = &args;
660 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
661 	va_end(args);
662 }
663 
664 #define ext4_warning_ratelimit(sb)					\
665 		___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state),	\
666 			     "EXT4-fs warning")
667 
668 void __ext4_warning(struct super_block *sb, const char *function,
669 		    unsigned int line, const char *fmt, ...)
670 {
671 	struct va_format vaf;
672 	va_list args;
673 
674 	if (!ext4_warning_ratelimit(sb))
675 		return;
676 
677 	va_start(args, fmt);
678 	vaf.fmt = fmt;
679 	vaf.va = &args;
680 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
681 	       sb->s_id, function, line, &vaf);
682 	va_end(args);
683 }
684 
685 void __ext4_warning_inode(const struct inode *inode, const char *function,
686 			  unsigned int line, const char *fmt, ...)
687 {
688 	struct va_format vaf;
689 	va_list args;
690 
691 	if (!ext4_warning_ratelimit(inode->i_sb))
692 		return;
693 
694 	va_start(args, fmt);
695 	vaf.fmt = fmt;
696 	vaf.va = &args;
697 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: "
698 	       "inode #%lu: comm %s: %pV\n", inode->i_sb->s_id,
699 	       function, line, inode->i_ino, current->comm, &vaf);
700 	va_end(args);
701 }
702 
703 void __ext4_grp_locked_error(const char *function, unsigned int line,
704 			     struct super_block *sb, ext4_group_t grp,
705 			     unsigned long ino, ext4_fsblk_t block,
706 			     const char *fmt, ...)
707 __releases(bitlock)
708 __acquires(bitlock)
709 {
710 	struct va_format vaf;
711 	va_list args;
712 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
713 
714 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
715 		return;
716 
717 	es->s_last_error_ino = cpu_to_le32(ino);
718 	es->s_last_error_block = cpu_to_le64(block);
719 	__save_error_info(sb, function, line);
720 
721 	if (ext4_error_ratelimit(sb)) {
722 		va_start(args, fmt);
723 		vaf.fmt = fmt;
724 		vaf.va = &args;
725 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
726 		       sb->s_id, function, line, grp);
727 		if (ino)
728 			printk(KERN_CONT "inode %lu: ", ino);
729 		if (block)
730 			printk(KERN_CONT "block %llu:",
731 			       (unsigned long long) block);
732 		printk(KERN_CONT "%pV\n", &vaf);
733 		va_end(args);
734 	}
735 
736 	if (test_opt(sb, ERRORS_CONT)) {
737 		ext4_commit_super(sb, 0);
738 		return;
739 	}
740 
741 	ext4_unlock_group(sb, grp);
742 	ext4_handle_error(sb);
743 	/*
744 	 * We only get here in the ERRORS_RO case; relocking the group
745 	 * may be dangerous, but nothing bad will happen since the
746 	 * filesystem will have already been marked read/only and the
747 	 * journal has been aborted.  We return 1 as a hint to callers
748 	 * who might what to use the return value from
749 	 * ext4_grp_locked_error() to distinguish between the
750 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
751 	 * aggressively from the ext4 function in question, with a
752 	 * more appropriate error code.
753 	 */
754 	ext4_lock_group(sb, grp);
755 	return;
756 }
757 
758 void ext4_update_dynamic_rev(struct super_block *sb)
759 {
760 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
761 
762 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
763 		return;
764 
765 	ext4_warning(sb,
766 		     "updating to rev %d because of new feature flag, "
767 		     "running e2fsck is recommended",
768 		     EXT4_DYNAMIC_REV);
769 
770 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
771 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
772 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
773 	/* leave es->s_feature_*compat flags alone */
774 	/* es->s_uuid will be set by e2fsck if empty */
775 
776 	/*
777 	 * The rest of the superblock fields should be zero, and if not it
778 	 * means they are likely already in use, so leave them alone.  We
779 	 * can leave it up to e2fsck to clean up any inconsistencies there.
780 	 */
781 }
782 
783 /*
784  * Open the external journal device
785  */
786 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
787 {
788 	struct block_device *bdev;
789 	char b[BDEVNAME_SIZE];
790 
791 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
792 	if (IS_ERR(bdev))
793 		goto fail;
794 	return bdev;
795 
796 fail:
797 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
798 			__bdevname(dev, b), PTR_ERR(bdev));
799 	return NULL;
800 }
801 
802 /*
803  * Release the journal device
804  */
805 static void ext4_blkdev_put(struct block_device *bdev)
806 {
807 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
808 }
809 
810 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
811 {
812 	struct block_device *bdev;
813 	bdev = sbi->journal_bdev;
814 	if (bdev) {
815 		ext4_blkdev_put(bdev);
816 		sbi->journal_bdev = NULL;
817 	}
818 }
819 
820 static inline struct inode *orphan_list_entry(struct list_head *l)
821 {
822 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
823 }
824 
825 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
826 {
827 	struct list_head *l;
828 
829 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
830 		 le32_to_cpu(sbi->s_es->s_last_orphan));
831 
832 	printk(KERN_ERR "sb_info orphan list:\n");
833 	list_for_each(l, &sbi->s_orphan) {
834 		struct inode *inode = orphan_list_entry(l);
835 		printk(KERN_ERR "  "
836 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
837 		       inode->i_sb->s_id, inode->i_ino, inode,
838 		       inode->i_mode, inode->i_nlink,
839 		       NEXT_ORPHAN(inode));
840 	}
841 }
842 
843 #ifdef CONFIG_QUOTA
844 static int ext4_quota_off(struct super_block *sb, int type);
845 
846 static inline void ext4_quota_off_umount(struct super_block *sb)
847 {
848 	int type;
849 
850 	if (ext4_has_feature_quota(sb)) {
851 		dquot_disable(sb, -1,
852 			      DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
853 	} else {
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 }
859 #else
860 static inline void ext4_quota_off_umount(struct super_block *sb)
861 {
862 }
863 #endif
864 
865 static void ext4_put_super(struct super_block *sb)
866 {
867 	struct ext4_sb_info *sbi = EXT4_SB(sb);
868 	struct ext4_super_block *es = sbi->s_es;
869 	int aborted = 0;
870 	int i, err;
871 
872 	ext4_unregister_li_request(sb);
873 	ext4_quota_off_umount(sb);
874 
875 	flush_workqueue(sbi->rsv_conversion_wq);
876 	destroy_workqueue(sbi->rsv_conversion_wq);
877 
878 	if (sbi->s_journal) {
879 		aborted = is_journal_aborted(sbi->s_journal);
880 		err = jbd2_journal_destroy(sbi->s_journal);
881 		sbi->s_journal = NULL;
882 		if ((err < 0) && !aborted)
883 			ext4_abort(sb, "Couldn't clean up the journal");
884 	}
885 
886 	ext4_unregister_sysfs(sb);
887 	ext4_es_unregister_shrinker(sbi);
888 	del_timer_sync(&sbi->s_err_report);
889 	ext4_release_system_zone(sb);
890 	ext4_mb_release(sb);
891 	ext4_ext_release(sb);
892 
893 	if (!(sb->s_flags & MS_RDONLY) && !aborted) {
894 		ext4_clear_feature_journal_needs_recovery(sb);
895 		es->s_state = cpu_to_le16(sbi->s_mount_state);
896 	}
897 	if (!(sb->s_flags & MS_RDONLY))
898 		ext4_commit_super(sb, 1);
899 
900 	for (i = 0; i < sbi->s_gdb_count; i++)
901 		brelse(sbi->s_group_desc[i]);
902 	kvfree(sbi->s_group_desc);
903 	kvfree(sbi->s_flex_groups);
904 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
905 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
906 	percpu_counter_destroy(&sbi->s_dirs_counter);
907 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
908 	percpu_free_rwsem(&sbi->s_journal_flag_rwsem);
909 #ifdef CONFIG_QUOTA
910 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
911 		kfree(sbi->s_qf_names[i]);
912 #endif
913 
914 	/* Debugging code just in case the in-memory inode orphan list
915 	 * isn't empty.  The on-disk one can be non-empty if we've
916 	 * detected an error and taken the fs readonly, but the
917 	 * in-memory list had better be clean by this point. */
918 	if (!list_empty(&sbi->s_orphan))
919 		dump_orphan_list(sb, sbi);
920 	J_ASSERT(list_empty(&sbi->s_orphan));
921 
922 	sync_blockdev(sb->s_bdev);
923 	invalidate_bdev(sb->s_bdev);
924 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
925 		/*
926 		 * Invalidate the journal device's buffers.  We don't want them
927 		 * floating about in memory - the physical journal device may
928 		 * hotswapped, and it breaks the `ro-after' testing code.
929 		 */
930 		sync_blockdev(sbi->journal_bdev);
931 		invalidate_bdev(sbi->journal_bdev);
932 		ext4_blkdev_remove(sbi);
933 	}
934 	if (sbi->s_mb_cache) {
935 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
936 		sbi->s_mb_cache = NULL;
937 	}
938 	if (sbi->s_mmp_tsk)
939 		kthread_stop(sbi->s_mmp_tsk);
940 	brelse(sbi->s_sbh);
941 	sb->s_fs_info = NULL;
942 	/*
943 	 * Now that we are completely done shutting down the
944 	 * superblock, we need to actually destroy the kobject.
945 	 */
946 	kobject_put(&sbi->s_kobj);
947 	wait_for_completion(&sbi->s_kobj_unregister);
948 	if (sbi->s_chksum_driver)
949 		crypto_free_shash(sbi->s_chksum_driver);
950 	kfree(sbi->s_blockgroup_lock);
951 	kfree(sbi);
952 }
953 
954 static struct kmem_cache *ext4_inode_cachep;
955 
956 /*
957  * Called inside transaction, so use GFP_NOFS
958  */
959 static struct inode *ext4_alloc_inode(struct super_block *sb)
960 {
961 	struct ext4_inode_info *ei;
962 
963 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
964 	if (!ei)
965 		return NULL;
966 
967 	ei->vfs_inode.i_version = 1;
968 	spin_lock_init(&ei->i_raw_lock);
969 	INIT_LIST_HEAD(&ei->i_prealloc_list);
970 	spin_lock_init(&ei->i_prealloc_lock);
971 	ext4_es_init_tree(&ei->i_es_tree);
972 	rwlock_init(&ei->i_es_lock);
973 	INIT_LIST_HEAD(&ei->i_es_list);
974 	ei->i_es_all_nr = 0;
975 	ei->i_es_shk_nr = 0;
976 	ei->i_es_shrink_lblk = 0;
977 	ei->i_reserved_data_blocks = 0;
978 	ei->i_reserved_meta_blocks = 0;
979 	ei->i_allocated_meta_blocks = 0;
980 	ei->i_da_metadata_calc_len = 0;
981 	ei->i_da_metadata_calc_last_lblock = 0;
982 	spin_lock_init(&(ei->i_block_reservation_lock));
983 #ifdef CONFIG_QUOTA
984 	ei->i_reserved_quota = 0;
985 	memset(&ei->i_dquot, 0, sizeof(ei->i_dquot));
986 #endif
987 	ei->jinode = NULL;
988 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
989 	spin_lock_init(&ei->i_completed_io_lock);
990 	ei->i_sync_tid = 0;
991 	ei->i_datasync_tid = 0;
992 	atomic_set(&ei->i_unwritten, 0);
993 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
994 	return &ei->vfs_inode;
995 }
996 
997 static int ext4_drop_inode(struct inode *inode)
998 {
999 	int drop = generic_drop_inode(inode);
1000 
1001 	trace_ext4_drop_inode(inode, drop);
1002 	return drop;
1003 }
1004 
1005 static void ext4_i_callback(struct rcu_head *head)
1006 {
1007 	struct inode *inode = container_of(head, struct inode, i_rcu);
1008 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
1009 }
1010 
1011 static void ext4_destroy_inode(struct inode *inode)
1012 {
1013 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
1014 		ext4_msg(inode->i_sb, KERN_ERR,
1015 			 "Inode %lu (%p): orphan list check failed!",
1016 			 inode->i_ino, EXT4_I(inode));
1017 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
1018 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1019 				true);
1020 		dump_stack();
1021 	}
1022 	call_rcu(&inode->i_rcu, ext4_i_callback);
1023 }
1024 
1025 static void init_once(void *foo)
1026 {
1027 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1028 
1029 	INIT_LIST_HEAD(&ei->i_orphan);
1030 	init_rwsem(&ei->xattr_sem);
1031 	init_rwsem(&ei->i_data_sem);
1032 	init_rwsem(&ei->i_mmap_sem);
1033 	inode_init_once(&ei->vfs_inode);
1034 }
1035 
1036 static int __init init_inodecache(void)
1037 {
1038 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1039 					     sizeof(struct ext4_inode_info),
1040 					     0, (SLAB_RECLAIM_ACCOUNT|
1041 						SLAB_MEM_SPREAD|SLAB_ACCOUNT),
1042 					     init_once);
1043 	if (ext4_inode_cachep == NULL)
1044 		return -ENOMEM;
1045 	return 0;
1046 }
1047 
1048 static void destroy_inodecache(void)
1049 {
1050 	/*
1051 	 * Make sure all delayed rcu free inodes are flushed before we
1052 	 * destroy cache.
1053 	 */
1054 	rcu_barrier();
1055 	kmem_cache_destroy(ext4_inode_cachep);
1056 }
1057 
1058 void ext4_clear_inode(struct inode *inode)
1059 {
1060 	invalidate_inode_buffers(inode);
1061 	clear_inode(inode);
1062 	dquot_drop(inode);
1063 	ext4_discard_preallocations(inode);
1064 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1065 	if (EXT4_I(inode)->jinode) {
1066 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1067 					       EXT4_I(inode)->jinode);
1068 		jbd2_free_inode(EXT4_I(inode)->jinode);
1069 		EXT4_I(inode)->jinode = NULL;
1070 	}
1071 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1072 	fscrypt_put_encryption_info(inode, NULL);
1073 #endif
1074 }
1075 
1076 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1077 					u64 ino, u32 generation)
1078 {
1079 	struct inode *inode;
1080 
1081 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1082 		return ERR_PTR(-ESTALE);
1083 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1084 		return ERR_PTR(-ESTALE);
1085 
1086 	/* iget isn't really right if the inode is currently unallocated!!
1087 	 *
1088 	 * ext4_read_inode will return a bad_inode if the inode had been
1089 	 * deleted, so we should be safe.
1090 	 *
1091 	 * Currently we don't know the generation for parent directory, so
1092 	 * a generation of 0 means "accept any"
1093 	 */
1094 	inode = ext4_iget_normal(sb, ino);
1095 	if (IS_ERR(inode))
1096 		return ERR_CAST(inode);
1097 	if (generation && inode->i_generation != generation) {
1098 		iput(inode);
1099 		return ERR_PTR(-ESTALE);
1100 	}
1101 
1102 	return inode;
1103 }
1104 
1105 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1106 					int fh_len, int fh_type)
1107 {
1108 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1109 				    ext4_nfs_get_inode);
1110 }
1111 
1112 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1113 					int fh_len, int fh_type)
1114 {
1115 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1116 				    ext4_nfs_get_inode);
1117 }
1118 
1119 /*
1120  * Try to release metadata pages (indirect blocks, directories) which are
1121  * mapped via the block device.  Since these pages could have journal heads
1122  * which would prevent try_to_free_buffers() from freeing them, we must use
1123  * jbd2 layer's try_to_free_buffers() function to release them.
1124  */
1125 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1126 				 gfp_t wait)
1127 {
1128 	journal_t *journal = EXT4_SB(sb)->s_journal;
1129 
1130 	WARN_ON(PageChecked(page));
1131 	if (!page_has_buffers(page))
1132 		return 0;
1133 	if (journal)
1134 		return jbd2_journal_try_to_free_buffers(journal, page,
1135 						wait & ~__GFP_DIRECT_RECLAIM);
1136 	return try_to_free_buffers(page);
1137 }
1138 
1139 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1140 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
1141 {
1142 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
1143 				 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
1144 }
1145 
1146 static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
1147 							void *fs_data)
1148 {
1149 	handle_t *handle = fs_data;
1150 	int res, res2, retries = 0;
1151 
1152 	res = ext4_convert_inline_data(inode);
1153 	if (res)
1154 		return res;
1155 
1156 	/*
1157 	 * If a journal handle was specified, then the encryption context is
1158 	 * being set on a new inode via inheritance and is part of a larger
1159 	 * transaction to create the inode.  Otherwise the encryption context is
1160 	 * being set on an existing inode in its own transaction.  Only in the
1161 	 * latter case should the "retry on ENOSPC" logic be used.
1162 	 */
1163 
1164 	if (handle) {
1165 		res = ext4_xattr_set_handle(handle, inode,
1166 					    EXT4_XATTR_INDEX_ENCRYPTION,
1167 					    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1168 					    ctx, len, 0);
1169 		if (!res) {
1170 			ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1171 			ext4_clear_inode_state(inode,
1172 					EXT4_STATE_MAY_INLINE_DATA);
1173 			/*
1174 			 * Update inode->i_flags - e.g. S_DAX may get disabled
1175 			 */
1176 			ext4_set_inode_flags(inode);
1177 		}
1178 		return res;
1179 	}
1180 
1181 retry:
1182 	handle = ext4_journal_start(inode, EXT4_HT_MISC,
1183 			ext4_jbd2_credits_xattr(inode));
1184 	if (IS_ERR(handle))
1185 		return PTR_ERR(handle);
1186 
1187 	res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
1188 				    EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
1189 				    ctx, len, 0);
1190 	if (!res) {
1191 		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
1192 		/* Update inode->i_flags - e.g. S_DAX may get disabled */
1193 		ext4_set_inode_flags(inode);
1194 		res = ext4_mark_inode_dirty(handle, inode);
1195 		if (res)
1196 			EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
1197 	}
1198 	res2 = ext4_journal_stop(handle);
1199 
1200 	if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
1201 		goto retry;
1202 	if (!res)
1203 		res = res2;
1204 	return res;
1205 }
1206 
1207 static int ext4_dummy_context(struct inode *inode)
1208 {
1209 	return DUMMY_ENCRYPTION_ENABLED(EXT4_SB(inode->i_sb));
1210 }
1211 
1212 static unsigned ext4_max_namelen(struct inode *inode)
1213 {
1214 	return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
1215 		EXT4_NAME_LEN;
1216 }
1217 
1218 static const struct fscrypt_operations ext4_cryptops = {
1219 	.key_prefix		= "ext4:",
1220 	.get_context		= ext4_get_context,
1221 	.set_context		= ext4_set_context,
1222 	.dummy_context		= ext4_dummy_context,
1223 	.is_encrypted		= ext4_encrypted_inode,
1224 	.empty_dir		= ext4_empty_dir,
1225 	.max_namelen		= ext4_max_namelen,
1226 };
1227 #else
1228 static const struct fscrypt_operations ext4_cryptops = {
1229 	.is_encrypted		= ext4_encrypted_inode,
1230 };
1231 #endif
1232 
1233 #ifdef CONFIG_QUOTA
1234 static const char * const quotatypes[] = INITQFNAMES;
1235 #define QTYPE2NAME(t) (quotatypes[t])
1236 
1237 static int ext4_write_dquot(struct dquot *dquot);
1238 static int ext4_acquire_dquot(struct dquot *dquot);
1239 static int ext4_release_dquot(struct dquot *dquot);
1240 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1241 static int ext4_write_info(struct super_block *sb, int type);
1242 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1243 			 const struct path *path);
1244 static int ext4_quota_on_mount(struct super_block *sb, int type);
1245 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1246 			       size_t len, loff_t off);
1247 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1248 				const char *data, size_t len, loff_t off);
1249 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1250 			     unsigned int flags);
1251 static int ext4_enable_quotas(struct super_block *sb);
1252 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid);
1253 
1254 static struct dquot **ext4_get_dquots(struct inode *inode)
1255 {
1256 	return EXT4_I(inode)->i_dquot;
1257 }
1258 
1259 static const struct dquot_operations ext4_quota_operations = {
1260 	.get_reserved_space = ext4_get_reserved_space,
1261 	.write_dquot	= ext4_write_dquot,
1262 	.acquire_dquot	= ext4_acquire_dquot,
1263 	.release_dquot	= ext4_release_dquot,
1264 	.mark_dirty	= ext4_mark_dquot_dirty,
1265 	.write_info	= ext4_write_info,
1266 	.alloc_dquot	= dquot_alloc,
1267 	.destroy_dquot	= dquot_destroy,
1268 	.get_projid	= ext4_get_projid,
1269 	.get_next_id	= ext4_get_next_id,
1270 };
1271 
1272 static const struct quotactl_ops ext4_qctl_operations = {
1273 	.quota_on	= ext4_quota_on,
1274 	.quota_off	= ext4_quota_off,
1275 	.quota_sync	= dquot_quota_sync,
1276 	.get_state	= dquot_get_state,
1277 	.set_info	= dquot_set_dqinfo,
1278 	.get_dqblk	= dquot_get_dqblk,
1279 	.set_dqblk	= dquot_set_dqblk,
1280 	.get_nextdqblk	= dquot_get_next_dqblk,
1281 };
1282 #endif
1283 
1284 static const struct super_operations ext4_sops = {
1285 	.alloc_inode	= ext4_alloc_inode,
1286 	.destroy_inode	= ext4_destroy_inode,
1287 	.write_inode	= ext4_write_inode,
1288 	.dirty_inode	= ext4_dirty_inode,
1289 	.drop_inode	= ext4_drop_inode,
1290 	.evict_inode	= ext4_evict_inode,
1291 	.put_super	= ext4_put_super,
1292 	.sync_fs	= ext4_sync_fs,
1293 	.freeze_fs	= ext4_freeze,
1294 	.unfreeze_fs	= ext4_unfreeze,
1295 	.statfs		= ext4_statfs,
1296 	.remount_fs	= ext4_remount,
1297 	.show_options	= ext4_show_options,
1298 #ifdef CONFIG_QUOTA
1299 	.quota_read	= ext4_quota_read,
1300 	.quota_write	= ext4_quota_write,
1301 	.get_dquots	= ext4_get_dquots,
1302 #endif
1303 	.bdev_try_to_free_page = bdev_try_to_free_page,
1304 };
1305 
1306 static const struct export_operations ext4_export_ops = {
1307 	.fh_to_dentry = ext4_fh_to_dentry,
1308 	.fh_to_parent = ext4_fh_to_parent,
1309 	.get_parent = ext4_get_parent,
1310 };
1311 
1312 enum {
1313 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1314 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1315 	Opt_nouid32, Opt_debug, Opt_removed,
1316 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1317 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1318 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_dev,
1319 	Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
1320 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1321 	Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
1322 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1323 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1324 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1325 	Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax,
1326 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1327 	Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize,
1328 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1329 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1330 	Opt_dioread_nolock, Opt_dioread_lock,
1331 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1332 	Opt_max_dir_size_kb, Opt_nojournal_checksum,
1333 };
1334 
1335 static const match_table_t tokens = {
1336 	{Opt_bsd_df, "bsddf"},
1337 	{Opt_minix_df, "minixdf"},
1338 	{Opt_grpid, "grpid"},
1339 	{Opt_grpid, "bsdgroups"},
1340 	{Opt_nogrpid, "nogrpid"},
1341 	{Opt_nogrpid, "sysvgroups"},
1342 	{Opt_resgid, "resgid=%u"},
1343 	{Opt_resuid, "resuid=%u"},
1344 	{Opt_sb, "sb=%u"},
1345 	{Opt_err_cont, "errors=continue"},
1346 	{Opt_err_panic, "errors=panic"},
1347 	{Opt_err_ro, "errors=remount-ro"},
1348 	{Opt_nouid32, "nouid32"},
1349 	{Opt_debug, "debug"},
1350 	{Opt_removed, "oldalloc"},
1351 	{Opt_removed, "orlov"},
1352 	{Opt_user_xattr, "user_xattr"},
1353 	{Opt_nouser_xattr, "nouser_xattr"},
1354 	{Opt_acl, "acl"},
1355 	{Opt_noacl, "noacl"},
1356 	{Opt_noload, "norecovery"},
1357 	{Opt_noload, "noload"},
1358 	{Opt_removed, "nobh"},
1359 	{Opt_removed, "bh"},
1360 	{Opt_commit, "commit=%u"},
1361 	{Opt_min_batch_time, "min_batch_time=%u"},
1362 	{Opt_max_batch_time, "max_batch_time=%u"},
1363 	{Opt_journal_dev, "journal_dev=%u"},
1364 	{Opt_journal_path, "journal_path=%s"},
1365 	{Opt_journal_checksum, "journal_checksum"},
1366 	{Opt_nojournal_checksum, "nojournal_checksum"},
1367 	{Opt_journal_async_commit, "journal_async_commit"},
1368 	{Opt_abort, "abort"},
1369 	{Opt_data_journal, "data=journal"},
1370 	{Opt_data_ordered, "data=ordered"},
1371 	{Opt_data_writeback, "data=writeback"},
1372 	{Opt_data_err_abort, "data_err=abort"},
1373 	{Opt_data_err_ignore, "data_err=ignore"},
1374 	{Opt_offusrjquota, "usrjquota="},
1375 	{Opt_usrjquota, "usrjquota=%s"},
1376 	{Opt_offgrpjquota, "grpjquota="},
1377 	{Opt_grpjquota, "grpjquota=%s"},
1378 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1379 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1380 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1381 	{Opt_grpquota, "grpquota"},
1382 	{Opt_noquota, "noquota"},
1383 	{Opt_quota, "quota"},
1384 	{Opt_usrquota, "usrquota"},
1385 	{Opt_prjquota, "prjquota"},
1386 	{Opt_barrier, "barrier=%u"},
1387 	{Opt_barrier, "barrier"},
1388 	{Opt_nobarrier, "nobarrier"},
1389 	{Opt_i_version, "i_version"},
1390 	{Opt_dax, "dax"},
1391 	{Opt_stripe, "stripe=%u"},
1392 	{Opt_delalloc, "delalloc"},
1393 	{Opt_lazytime, "lazytime"},
1394 	{Opt_nolazytime, "nolazytime"},
1395 	{Opt_debug_want_extra_isize, "debug_want_extra_isize=%u"},
1396 	{Opt_nodelalloc, "nodelalloc"},
1397 	{Opt_removed, "mblk_io_submit"},
1398 	{Opt_removed, "nomblk_io_submit"},
1399 	{Opt_block_validity, "block_validity"},
1400 	{Opt_noblock_validity, "noblock_validity"},
1401 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1402 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1403 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1404 	{Opt_auto_da_alloc, "auto_da_alloc"},
1405 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1406 	{Opt_dioread_nolock, "dioread_nolock"},
1407 	{Opt_dioread_lock, "dioread_lock"},
1408 	{Opt_discard, "discard"},
1409 	{Opt_nodiscard, "nodiscard"},
1410 	{Opt_init_itable, "init_itable=%u"},
1411 	{Opt_init_itable, "init_itable"},
1412 	{Opt_noinit_itable, "noinit_itable"},
1413 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1414 	{Opt_test_dummy_encryption, "test_dummy_encryption"},
1415 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1416 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1417 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1418 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1419 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1420 	{Opt_err, NULL},
1421 };
1422 
1423 static ext4_fsblk_t get_sb_block(void **data)
1424 {
1425 	ext4_fsblk_t	sb_block;
1426 	char		*options = (char *) *data;
1427 
1428 	if (!options || strncmp(options, "sb=", 3) != 0)
1429 		return 1;	/* Default location */
1430 
1431 	options += 3;
1432 	/* TODO: use simple_strtoll with >32bit ext4 */
1433 	sb_block = simple_strtoul(options, &options, 0);
1434 	if (*options && *options != ',') {
1435 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1436 		       (char *) *data);
1437 		return 1;
1438 	}
1439 	if (*options == ',')
1440 		options++;
1441 	*data = (void *) options;
1442 
1443 	return sb_block;
1444 }
1445 
1446 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1447 static const char deprecated_msg[] =
1448 	"Mount option \"%s\" will be removed by %s\n"
1449 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1450 
1451 #ifdef CONFIG_QUOTA
1452 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1453 {
1454 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1455 	char *qname;
1456 	int ret = -1;
1457 
1458 	if (sb_any_quota_loaded(sb) &&
1459 		!sbi->s_qf_names[qtype]) {
1460 		ext4_msg(sb, KERN_ERR,
1461 			"Cannot change journaled "
1462 			"quota options when quota turned on");
1463 		return -1;
1464 	}
1465 	if (ext4_has_feature_quota(sb)) {
1466 		ext4_msg(sb, KERN_INFO, "Journaled quota options "
1467 			 "ignored when QUOTA feature is enabled");
1468 		return 1;
1469 	}
1470 	qname = match_strdup(args);
1471 	if (!qname) {
1472 		ext4_msg(sb, KERN_ERR,
1473 			"Not enough memory for storing quotafile name");
1474 		return -1;
1475 	}
1476 	if (sbi->s_qf_names[qtype]) {
1477 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1478 			ret = 1;
1479 		else
1480 			ext4_msg(sb, KERN_ERR,
1481 				 "%s quota file already specified",
1482 				 QTYPE2NAME(qtype));
1483 		goto errout;
1484 	}
1485 	if (strchr(qname, '/')) {
1486 		ext4_msg(sb, KERN_ERR,
1487 			"quotafile must be on filesystem root");
1488 		goto errout;
1489 	}
1490 	sbi->s_qf_names[qtype] = qname;
1491 	set_opt(sb, QUOTA);
1492 	return 1;
1493 errout:
1494 	kfree(qname);
1495 	return ret;
1496 }
1497 
1498 static int clear_qf_name(struct super_block *sb, int qtype)
1499 {
1500 
1501 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1502 
1503 	if (sb_any_quota_loaded(sb) &&
1504 		sbi->s_qf_names[qtype]) {
1505 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1506 			" when quota turned on");
1507 		return -1;
1508 	}
1509 	kfree(sbi->s_qf_names[qtype]);
1510 	sbi->s_qf_names[qtype] = NULL;
1511 	return 1;
1512 }
1513 #endif
1514 
1515 #define MOPT_SET	0x0001
1516 #define MOPT_CLEAR	0x0002
1517 #define MOPT_NOSUPPORT	0x0004
1518 #define MOPT_EXPLICIT	0x0008
1519 #define MOPT_CLEAR_ERR	0x0010
1520 #define MOPT_GTE0	0x0020
1521 #ifdef CONFIG_QUOTA
1522 #define MOPT_Q		0
1523 #define MOPT_QFMT	0x0040
1524 #else
1525 #define MOPT_Q		MOPT_NOSUPPORT
1526 #define MOPT_QFMT	MOPT_NOSUPPORT
1527 #endif
1528 #define MOPT_DATAJ	0x0080
1529 #define MOPT_NO_EXT2	0x0100
1530 #define MOPT_NO_EXT3	0x0200
1531 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1532 #define MOPT_STRING	0x0400
1533 
1534 static const struct mount_opts {
1535 	int	token;
1536 	int	mount_opt;
1537 	int	flags;
1538 } ext4_mount_opts[] = {
1539 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1540 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1541 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1542 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1543 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1544 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1545 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1546 	 MOPT_EXT4_ONLY | MOPT_SET},
1547 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1548 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1549 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1550 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1551 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1552 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1553 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1554 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1555 	{Opt_nojournal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1556 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1557 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1558 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1559 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1560 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1561 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1562 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1563 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1564 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1565 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1566 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1567 	 MOPT_NO_EXT2},
1568 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1569 	 MOPT_NO_EXT2},
1570 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1571 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1572 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1573 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1574 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1575 	{Opt_commit, 0, MOPT_GTE0},
1576 	{Opt_max_batch_time, 0, MOPT_GTE0},
1577 	{Opt_min_batch_time, 0, MOPT_GTE0},
1578 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1579 	{Opt_init_itable, 0, MOPT_GTE0},
1580 	{Opt_dax, EXT4_MOUNT_DAX, MOPT_SET},
1581 	{Opt_stripe, 0, MOPT_GTE0},
1582 	{Opt_resuid, 0, MOPT_GTE0},
1583 	{Opt_resgid, 0, MOPT_GTE0},
1584 	{Opt_journal_dev, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1585 	{Opt_journal_path, 0, MOPT_NO_EXT2 | MOPT_STRING},
1586 	{Opt_journal_ioprio, 0, MOPT_NO_EXT2 | MOPT_GTE0},
1587 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1588 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1589 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1590 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1591 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1592 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1593 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1594 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1595 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1596 #else
1597 	{Opt_acl, 0, MOPT_NOSUPPORT},
1598 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1599 #endif
1600 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1601 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1602 	{Opt_debug_want_extra_isize, 0, MOPT_GTE0},
1603 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1604 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1605 							MOPT_SET | MOPT_Q},
1606 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1607 							MOPT_SET | MOPT_Q},
1608 	{Opt_prjquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_PRJQUOTA,
1609 							MOPT_SET | MOPT_Q},
1610 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1611 		       EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA),
1612 							MOPT_CLEAR | MOPT_Q},
1613 	{Opt_usrjquota, 0, MOPT_Q},
1614 	{Opt_grpjquota, 0, MOPT_Q},
1615 	{Opt_offusrjquota, 0, MOPT_Q},
1616 	{Opt_offgrpjquota, 0, MOPT_Q},
1617 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1618 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1619 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1620 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1621 	{Opt_test_dummy_encryption, 0, MOPT_GTE0},
1622 	{Opt_err, 0, 0}
1623 };
1624 
1625 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1626 			    substring_t *args, unsigned long *journal_devnum,
1627 			    unsigned int *journal_ioprio, int is_remount)
1628 {
1629 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1630 	const struct mount_opts *m;
1631 	kuid_t uid;
1632 	kgid_t gid;
1633 	int arg = 0;
1634 
1635 #ifdef CONFIG_QUOTA
1636 	if (token == Opt_usrjquota)
1637 		return set_qf_name(sb, USRQUOTA, &args[0]);
1638 	else if (token == Opt_grpjquota)
1639 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1640 	else if (token == Opt_offusrjquota)
1641 		return clear_qf_name(sb, USRQUOTA);
1642 	else if (token == Opt_offgrpjquota)
1643 		return clear_qf_name(sb, GRPQUOTA);
1644 #endif
1645 	switch (token) {
1646 	case Opt_noacl:
1647 	case Opt_nouser_xattr:
1648 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1649 		break;
1650 	case Opt_sb:
1651 		return 1;	/* handled by get_sb_block() */
1652 	case Opt_removed:
1653 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1654 		return 1;
1655 	case Opt_abort:
1656 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1657 		return 1;
1658 	case Opt_i_version:
1659 		sb->s_flags |= MS_I_VERSION;
1660 		return 1;
1661 	case Opt_lazytime:
1662 		sb->s_flags |= MS_LAZYTIME;
1663 		return 1;
1664 	case Opt_nolazytime:
1665 		sb->s_flags &= ~MS_LAZYTIME;
1666 		return 1;
1667 	}
1668 
1669 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1670 		if (token == m->token)
1671 			break;
1672 
1673 	if (m->token == Opt_err) {
1674 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1675 			 "or missing value", opt);
1676 		return -1;
1677 	}
1678 
1679 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1680 		ext4_msg(sb, KERN_ERR,
1681 			 "Mount option \"%s\" incompatible with ext2", opt);
1682 		return -1;
1683 	}
1684 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1685 		ext4_msg(sb, KERN_ERR,
1686 			 "Mount option \"%s\" incompatible with ext3", opt);
1687 		return -1;
1688 	}
1689 
1690 	if (args->from && !(m->flags & MOPT_STRING) && match_int(args, &arg))
1691 		return -1;
1692 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1693 		return -1;
1694 	if (m->flags & MOPT_EXPLICIT) {
1695 		if (m->mount_opt & EXT4_MOUNT_DELALLOC) {
1696 			set_opt2(sb, EXPLICIT_DELALLOC);
1697 		} else if (m->mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) {
1698 			set_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM);
1699 		} else
1700 			return -1;
1701 	}
1702 	if (m->flags & MOPT_CLEAR_ERR)
1703 		clear_opt(sb, ERRORS_MASK);
1704 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1705 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1706 			 "options when quota turned on");
1707 		return -1;
1708 	}
1709 
1710 	if (m->flags & MOPT_NOSUPPORT) {
1711 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1712 	} else if (token == Opt_commit) {
1713 		if (arg == 0)
1714 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1715 		sbi->s_commit_interval = HZ * arg;
1716 	} else if (token == Opt_debug_want_extra_isize) {
1717 		sbi->s_want_extra_isize = arg;
1718 	} else if (token == Opt_max_batch_time) {
1719 		sbi->s_max_batch_time = arg;
1720 	} else if (token == Opt_min_batch_time) {
1721 		sbi->s_min_batch_time = arg;
1722 	} else if (token == Opt_inode_readahead_blks) {
1723 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1724 			ext4_msg(sb, KERN_ERR,
1725 				 "EXT4-fs: inode_readahead_blks must be "
1726 				 "0 or a power of 2 smaller than 2^31");
1727 			return -1;
1728 		}
1729 		sbi->s_inode_readahead_blks = arg;
1730 	} else if (token == Opt_init_itable) {
1731 		set_opt(sb, INIT_INODE_TABLE);
1732 		if (!args->from)
1733 			arg = EXT4_DEF_LI_WAIT_MULT;
1734 		sbi->s_li_wait_mult = arg;
1735 	} else if (token == Opt_max_dir_size_kb) {
1736 		sbi->s_max_dir_size_kb = arg;
1737 	} else if (token == Opt_stripe) {
1738 		sbi->s_stripe = arg;
1739 	} else if (token == Opt_resuid) {
1740 		uid = make_kuid(current_user_ns(), arg);
1741 		if (!uid_valid(uid)) {
1742 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1743 			return -1;
1744 		}
1745 		sbi->s_resuid = uid;
1746 	} else if (token == Opt_resgid) {
1747 		gid = make_kgid(current_user_ns(), arg);
1748 		if (!gid_valid(gid)) {
1749 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1750 			return -1;
1751 		}
1752 		sbi->s_resgid = gid;
1753 	} else if (token == Opt_journal_dev) {
1754 		if (is_remount) {
1755 			ext4_msg(sb, KERN_ERR,
1756 				 "Cannot specify journal on remount");
1757 			return -1;
1758 		}
1759 		*journal_devnum = arg;
1760 	} else if (token == Opt_journal_path) {
1761 		char *journal_path;
1762 		struct inode *journal_inode;
1763 		struct path path;
1764 		int error;
1765 
1766 		if (is_remount) {
1767 			ext4_msg(sb, KERN_ERR,
1768 				 "Cannot specify journal on remount");
1769 			return -1;
1770 		}
1771 		journal_path = match_strdup(&args[0]);
1772 		if (!journal_path) {
1773 			ext4_msg(sb, KERN_ERR, "error: could not dup "
1774 				"journal device string");
1775 			return -1;
1776 		}
1777 
1778 		error = kern_path(journal_path, LOOKUP_FOLLOW, &path);
1779 		if (error) {
1780 			ext4_msg(sb, KERN_ERR, "error: could not find "
1781 				"journal device path: error %d", error);
1782 			kfree(journal_path);
1783 			return -1;
1784 		}
1785 
1786 		journal_inode = d_inode(path.dentry);
1787 		if (!S_ISBLK(journal_inode->i_mode)) {
1788 			ext4_msg(sb, KERN_ERR, "error: journal path %s "
1789 				"is not a block device", journal_path);
1790 			path_put(&path);
1791 			kfree(journal_path);
1792 			return -1;
1793 		}
1794 
1795 		*journal_devnum = new_encode_dev(journal_inode->i_rdev);
1796 		path_put(&path);
1797 		kfree(journal_path);
1798 	} else if (token == Opt_journal_ioprio) {
1799 		if (arg > 7) {
1800 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1801 				 " (must be 0-7)");
1802 			return -1;
1803 		}
1804 		*journal_ioprio =
1805 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1806 	} else if (token == Opt_test_dummy_encryption) {
1807 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1808 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
1809 		ext4_msg(sb, KERN_WARNING,
1810 			 "Test dummy encryption mode enabled");
1811 #else
1812 		ext4_msg(sb, KERN_WARNING,
1813 			 "Test dummy encryption mount option ignored");
1814 #endif
1815 	} else if (m->flags & MOPT_DATAJ) {
1816 		if (is_remount) {
1817 			if (!sbi->s_journal)
1818 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1819 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1820 				ext4_msg(sb, KERN_ERR,
1821 					 "Cannot change data mode on remount");
1822 				return -1;
1823 			}
1824 		} else {
1825 			clear_opt(sb, DATA_FLAGS);
1826 			sbi->s_mount_opt |= m->mount_opt;
1827 		}
1828 #ifdef CONFIG_QUOTA
1829 	} else if (m->flags & MOPT_QFMT) {
1830 		if (sb_any_quota_loaded(sb) &&
1831 		    sbi->s_jquota_fmt != m->mount_opt) {
1832 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1833 				 "quota options when quota turned on");
1834 			return -1;
1835 		}
1836 		if (ext4_has_feature_quota(sb)) {
1837 			ext4_msg(sb, KERN_INFO,
1838 				 "Quota format mount options ignored "
1839 				 "when QUOTA feature is enabled");
1840 			return 1;
1841 		}
1842 		sbi->s_jquota_fmt = m->mount_opt;
1843 #endif
1844 	} else if (token == Opt_dax) {
1845 #ifdef CONFIG_FS_DAX
1846 		ext4_msg(sb, KERN_WARNING,
1847 		"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");
1848 			sbi->s_mount_opt |= m->mount_opt;
1849 #else
1850 		ext4_msg(sb, KERN_INFO, "dax option not supported");
1851 		return -1;
1852 #endif
1853 	} else if (token == Opt_data_err_abort) {
1854 		sbi->s_mount_opt |= m->mount_opt;
1855 	} else if (token == Opt_data_err_ignore) {
1856 		sbi->s_mount_opt &= ~m->mount_opt;
1857 	} else {
1858 		if (!args->from)
1859 			arg = 1;
1860 		if (m->flags & MOPT_CLEAR)
1861 			arg = !arg;
1862 		else if (unlikely(!(m->flags & MOPT_SET))) {
1863 			ext4_msg(sb, KERN_WARNING,
1864 				 "buggy handling of option %s", opt);
1865 			WARN_ON(1);
1866 			return -1;
1867 		}
1868 		if (arg != 0)
1869 			sbi->s_mount_opt |= m->mount_opt;
1870 		else
1871 			sbi->s_mount_opt &= ~m->mount_opt;
1872 	}
1873 	return 1;
1874 }
1875 
1876 static int parse_options(char *options, struct super_block *sb,
1877 			 unsigned long *journal_devnum,
1878 			 unsigned int *journal_ioprio,
1879 			 int is_remount)
1880 {
1881 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1882 	char *p;
1883 	substring_t args[MAX_OPT_ARGS];
1884 	int token;
1885 
1886 	if (!options)
1887 		return 1;
1888 
1889 	while ((p = strsep(&options, ",")) != NULL) {
1890 		if (!*p)
1891 			continue;
1892 		/*
1893 		 * Initialize args struct so we know whether arg was
1894 		 * found; some options take optional arguments.
1895 		 */
1896 		args[0].to = args[0].from = NULL;
1897 		token = match_token(p, tokens, args);
1898 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1899 				     journal_ioprio, is_remount) < 0)
1900 			return 0;
1901 	}
1902 #ifdef CONFIG_QUOTA
1903 	/*
1904 	 * We do the test below only for project quotas. 'usrquota' and
1905 	 * 'grpquota' mount options are allowed even without quota feature
1906 	 * to support legacy quotas in quota files.
1907 	 */
1908 	if (test_opt(sb, PRJQUOTA) && !ext4_has_feature_project(sb)) {
1909 		ext4_msg(sb, KERN_ERR, "Project quota feature not enabled. "
1910 			 "Cannot enable project quota enforcement.");
1911 		return 0;
1912 	}
1913 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1914 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1915 			clear_opt(sb, USRQUOTA);
1916 
1917 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1918 			clear_opt(sb, GRPQUOTA);
1919 
1920 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1921 			ext4_msg(sb, KERN_ERR, "old and new quota "
1922 					"format mixing");
1923 			return 0;
1924 		}
1925 
1926 		if (!sbi->s_jquota_fmt) {
1927 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1928 					"not specified");
1929 			return 0;
1930 		}
1931 	}
1932 #endif
1933 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1934 		int blocksize =
1935 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1936 
1937 		if (blocksize < PAGE_SIZE) {
1938 			ext4_msg(sb, KERN_ERR, "can't mount with "
1939 				 "dioread_nolock if block size != PAGE_SIZE");
1940 			return 0;
1941 		}
1942 	}
1943 	return 1;
1944 }
1945 
1946 static inline void ext4_show_quota_options(struct seq_file *seq,
1947 					   struct super_block *sb)
1948 {
1949 #if defined(CONFIG_QUOTA)
1950 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1951 
1952 	if (sbi->s_jquota_fmt) {
1953 		char *fmtname = "";
1954 
1955 		switch (sbi->s_jquota_fmt) {
1956 		case QFMT_VFS_OLD:
1957 			fmtname = "vfsold";
1958 			break;
1959 		case QFMT_VFS_V0:
1960 			fmtname = "vfsv0";
1961 			break;
1962 		case QFMT_VFS_V1:
1963 			fmtname = "vfsv1";
1964 			break;
1965 		}
1966 		seq_printf(seq, ",jqfmt=%s", fmtname);
1967 	}
1968 
1969 	if (sbi->s_qf_names[USRQUOTA])
1970 		seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
1971 
1972 	if (sbi->s_qf_names[GRPQUOTA])
1973 		seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
1974 #endif
1975 }
1976 
1977 static const char *token2str(int token)
1978 {
1979 	const struct match_token *t;
1980 
1981 	for (t = tokens; t->token != Opt_err; t++)
1982 		if (t->token == token && !strchr(t->pattern, '='))
1983 			break;
1984 	return t->pattern;
1985 }
1986 
1987 /*
1988  * Show an option if
1989  *  - it's set to a non-default value OR
1990  *  - if the per-sb default is different from the global default
1991  */
1992 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1993 			      int nodefs)
1994 {
1995 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1996 	struct ext4_super_block *es = sbi->s_es;
1997 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1998 	const struct mount_opts *m;
1999 	char sep = nodefs ? '\n' : ',';
2000 
2001 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
2002 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
2003 
2004 	if (sbi->s_sb_block != 1)
2005 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
2006 
2007 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
2008 		int want_set = m->flags & MOPT_SET;
2009 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
2010 		    (m->flags & MOPT_CLEAR_ERR))
2011 			continue;
2012 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
2013 			continue; /* skip if same as the default */
2014 		if ((want_set &&
2015 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
2016 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
2017 			continue; /* select Opt_noFoo vs Opt_Foo */
2018 		SEQ_OPTS_PRINT("%s", token2str(m->token));
2019 	}
2020 
2021 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
2022 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
2023 		SEQ_OPTS_PRINT("resuid=%u",
2024 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
2025 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
2026 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
2027 		SEQ_OPTS_PRINT("resgid=%u",
2028 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
2029 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
2030 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
2031 		SEQ_OPTS_PUTS("errors=remount-ro");
2032 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
2033 		SEQ_OPTS_PUTS("errors=continue");
2034 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
2035 		SEQ_OPTS_PUTS("errors=panic");
2036 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
2037 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
2038 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
2039 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
2040 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
2041 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
2042 	if (sb->s_flags & MS_I_VERSION)
2043 		SEQ_OPTS_PUTS("i_version");
2044 	if (nodefs || sbi->s_stripe)
2045 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
2046 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
2047 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
2048 			SEQ_OPTS_PUTS("data=journal");
2049 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
2050 			SEQ_OPTS_PUTS("data=ordered");
2051 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
2052 			SEQ_OPTS_PUTS("data=writeback");
2053 	}
2054 	if (nodefs ||
2055 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
2056 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
2057 			       sbi->s_inode_readahead_blks);
2058 
2059 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
2060 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
2061 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
2062 	if (nodefs || sbi->s_max_dir_size_kb)
2063 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
2064 	if (test_opt(sb, DATA_ERR_ABORT))
2065 		SEQ_OPTS_PUTS("data_err=abort");
2066 
2067 	ext4_show_quota_options(seq, sb);
2068 	return 0;
2069 }
2070 
2071 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
2072 {
2073 	return _ext4_show_options(seq, root->d_sb, 0);
2074 }
2075 
2076 int ext4_seq_options_show(struct seq_file *seq, void *offset)
2077 {
2078 	struct super_block *sb = seq->private;
2079 	int rc;
2080 
2081 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
2082 	rc = _ext4_show_options(seq, sb, 1);
2083 	seq_puts(seq, "\n");
2084 	return rc;
2085 }
2086 
2087 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
2088 			    int read_only)
2089 {
2090 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2091 	int res = 0;
2092 
2093 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
2094 		ext4_msg(sb, KERN_ERR, "revision level too high, "
2095 			 "forcing read-only mode");
2096 		res = MS_RDONLY;
2097 	}
2098 	if (read_only)
2099 		goto done;
2100 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
2101 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
2102 			 "running e2fsck is recommended");
2103 	else if (sbi->s_mount_state & EXT4_ERROR_FS)
2104 		ext4_msg(sb, KERN_WARNING,
2105 			 "warning: mounting fs with errors, "
2106 			 "running e2fsck is recommended");
2107 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
2108 		 le16_to_cpu(es->s_mnt_count) >=
2109 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
2110 		ext4_msg(sb, KERN_WARNING,
2111 			 "warning: maximal mount count reached, "
2112 			 "running e2fsck is recommended");
2113 	else if (le32_to_cpu(es->s_checkinterval) &&
2114 		(le32_to_cpu(es->s_lastcheck) +
2115 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
2116 		ext4_msg(sb, KERN_WARNING,
2117 			 "warning: checktime reached, "
2118 			 "running e2fsck is recommended");
2119 	if (!sbi->s_journal)
2120 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
2121 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
2122 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
2123 	le16_add_cpu(&es->s_mnt_count, 1);
2124 	es->s_mtime = cpu_to_le32(get_seconds());
2125 	ext4_update_dynamic_rev(sb);
2126 	if (sbi->s_journal)
2127 		ext4_set_feature_journal_needs_recovery(sb);
2128 
2129 	ext4_commit_super(sb, 1);
2130 done:
2131 	if (test_opt(sb, DEBUG))
2132 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
2133 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
2134 			sb->s_blocksize,
2135 			sbi->s_groups_count,
2136 			EXT4_BLOCKS_PER_GROUP(sb),
2137 			EXT4_INODES_PER_GROUP(sb),
2138 			sbi->s_mount_opt, sbi->s_mount_opt2);
2139 
2140 	cleancache_init_fs(sb);
2141 	return res;
2142 }
2143 
2144 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
2145 {
2146 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2147 	struct flex_groups *new_groups;
2148 	int size;
2149 
2150 	if (!sbi->s_log_groups_per_flex)
2151 		return 0;
2152 
2153 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
2154 	if (size <= sbi->s_flex_groups_allocated)
2155 		return 0;
2156 
2157 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
2158 	new_groups = kvzalloc(size, GFP_KERNEL);
2159 	if (!new_groups) {
2160 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
2161 			 size / (int) sizeof(struct flex_groups));
2162 		return -ENOMEM;
2163 	}
2164 
2165 	if (sbi->s_flex_groups) {
2166 		memcpy(new_groups, sbi->s_flex_groups,
2167 		       (sbi->s_flex_groups_allocated *
2168 			sizeof(struct flex_groups)));
2169 		kvfree(sbi->s_flex_groups);
2170 	}
2171 	sbi->s_flex_groups = new_groups;
2172 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
2173 	return 0;
2174 }
2175 
2176 static int ext4_fill_flex_info(struct super_block *sb)
2177 {
2178 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2179 	struct ext4_group_desc *gdp = NULL;
2180 	ext4_group_t flex_group;
2181 	int i, err;
2182 
2183 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
2184 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
2185 		sbi->s_log_groups_per_flex = 0;
2186 		return 1;
2187 	}
2188 
2189 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
2190 	if (err)
2191 		goto failed;
2192 
2193 	for (i = 0; i < sbi->s_groups_count; i++) {
2194 		gdp = ext4_get_group_desc(sb, i, NULL);
2195 
2196 		flex_group = ext4_flex_group(sbi, i);
2197 		atomic_add(ext4_free_inodes_count(sb, gdp),
2198 			   &sbi->s_flex_groups[flex_group].free_inodes);
2199 		atomic64_add(ext4_free_group_clusters(sb, gdp),
2200 			     &sbi->s_flex_groups[flex_group].free_clusters);
2201 		atomic_add(ext4_used_dirs_count(sb, gdp),
2202 			   &sbi->s_flex_groups[flex_group].used_dirs);
2203 	}
2204 
2205 	return 1;
2206 failed:
2207 	return 0;
2208 }
2209 
2210 static __le16 ext4_group_desc_csum(struct super_block *sb, __u32 block_group,
2211 				   struct ext4_group_desc *gdp)
2212 {
2213 	int offset = offsetof(struct ext4_group_desc, bg_checksum);
2214 	__u16 crc = 0;
2215 	__le32 le_group = cpu_to_le32(block_group);
2216 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2217 
2218 	if (ext4_has_metadata_csum(sbi->s_sb)) {
2219 		/* Use new metadata_csum algorithm */
2220 		__u32 csum32;
2221 		__u16 dummy_csum = 0;
2222 
2223 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2224 				     sizeof(le_group));
2225 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp, offset);
2226 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)&dummy_csum,
2227 				     sizeof(dummy_csum));
2228 		offset += sizeof(dummy_csum);
2229 		if (offset < sbi->s_desc_size)
2230 			csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp + offset,
2231 					     sbi->s_desc_size - offset);
2232 
2233 		crc = csum32 & 0xFFFF;
2234 		goto out;
2235 	}
2236 
2237 	/* old crc16 code */
2238 	if (!ext4_has_feature_gdt_csum(sb))
2239 		return 0;
2240 
2241 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2242 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2243 	crc = crc16(crc, (__u8 *)gdp, offset);
2244 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2245 	/* for checksum of struct ext4_group_desc do the rest...*/
2246 	if (ext4_has_feature_64bit(sb) &&
2247 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2248 		crc = crc16(crc, (__u8 *)gdp + offset,
2249 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2250 				offset);
2251 
2252 out:
2253 	return cpu_to_le16(crc);
2254 }
2255 
2256 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2257 				struct ext4_group_desc *gdp)
2258 {
2259 	if (ext4_has_group_desc_csum(sb) &&
2260 	    (gdp->bg_checksum != ext4_group_desc_csum(sb, block_group, gdp)))
2261 		return 0;
2262 
2263 	return 1;
2264 }
2265 
2266 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2267 			      struct ext4_group_desc *gdp)
2268 {
2269 	if (!ext4_has_group_desc_csum(sb))
2270 		return;
2271 	gdp->bg_checksum = ext4_group_desc_csum(sb, block_group, gdp);
2272 }
2273 
2274 /* Called at mount-time, super-block is locked */
2275 static int ext4_check_descriptors(struct super_block *sb,
2276 				  ext4_fsblk_t sb_block,
2277 				  ext4_group_t *first_not_zeroed)
2278 {
2279 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2280 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2281 	ext4_fsblk_t last_block;
2282 	ext4_fsblk_t block_bitmap;
2283 	ext4_fsblk_t inode_bitmap;
2284 	ext4_fsblk_t inode_table;
2285 	int flexbg_flag = 0;
2286 	ext4_group_t i, grp = sbi->s_groups_count;
2287 
2288 	if (ext4_has_feature_flex_bg(sb))
2289 		flexbg_flag = 1;
2290 
2291 	ext4_debug("Checking group descriptors");
2292 
2293 	for (i = 0; i < sbi->s_groups_count; i++) {
2294 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2295 
2296 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2297 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2298 		else
2299 			last_block = first_block +
2300 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2301 
2302 		if ((grp == sbi->s_groups_count) &&
2303 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2304 			grp = i;
2305 
2306 		block_bitmap = ext4_block_bitmap(sb, gdp);
2307 		if (block_bitmap == sb_block) {
2308 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2309 				 "Block bitmap for group %u overlaps "
2310 				 "superblock", i);
2311 		}
2312 		if (block_bitmap < first_block || block_bitmap > last_block) {
2313 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2314 			       "Block bitmap for group %u not in group "
2315 			       "(block %llu)!", i, block_bitmap);
2316 			return 0;
2317 		}
2318 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2319 		if (inode_bitmap == sb_block) {
2320 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2321 				 "Inode bitmap for group %u overlaps "
2322 				 "superblock", i);
2323 		}
2324 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2325 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2326 			       "Inode bitmap for group %u not in group "
2327 			       "(block %llu)!", i, inode_bitmap);
2328 			return 0;
2329 		}
2330 		inode_table = ext4_inode_table(sb, gdp);
2331 		if (inode_table == sb_block) {
2332 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2333 				 "Inode table for group %u overlaps "
2334 				 "superblock", i);
2335 		}
2336 		if (inode_table < first_block ||
2337 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2338 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2339 			       "Inode table for group %u not in group "
2340 			       "(block %llu)!", i, inode_table);
2341 			return 0;
2342 		}
2343 		ext4_lock_group(sb, i);
2344 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2345 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2346 				 "Checksum for group %u failed (%u!=%u)",
2347 				 i, le16_to_cpu(ext4_group_desc_csum(sb, i,
2348 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2349 			if (!(sb->s_flags & MS_RDONLY)) {
2350 				ext4_unlock_group(sb, i);
2351 				return 0;
2352 			}
2353 		}
2354 		ext4_unlock_group(sb, i);
2355 		if (!flexbg_flag)
2356 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2357 	}
2358 	if (NULL != first_not_zeroed)
2359 		*first_not_zeroed = grp;
2360 	return 1;
2361 }
2362 
2363 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2364  * the superblock) which were deleted from all directories, but held open by
2365  * a process at the time of a crash.  We walk the list and try to delete these
2366  * inodes at recovery time (only with a read-write filesystem).
2367  *
2368  * In order to keep the orphan inode chain consistent during traversal (in
2369  * case of crash during recovery), we link each inode into the superblock
2370  * orphan list_head and handle it the same way as an inode deletion during
2371  * normal operation (which journals the operations for us).
2372  *
2373  * We only do an iget() and an iput() on each inode, which is very safe if we
2374  * accidentally point at an in-use or already deleted inode.  The worst that
2375  * can happen in this case is that we get a "bit already cleared" message from
2376  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2377  * e2fsck was run on this filesystem, and it must have already done the orphan
2378  * inode cleanup for us, so we can safely abort without any further action.
2379  */
2380 static void ext4_orphan_cleanup(struct super_block *sb,
2381 				struct ext4_super_block *es)
2382 {
2383 	unsigned int s_flags = sb->s_flags;
2384 	int ret, nr_orphans = 0, nr_truncates = 0;
2385 #ifdef CONFIG_QUOTA
2386 	int i;
2387 #endif
2388 	if (!es->s_last_orphan) {
2389 		jbd_debug(4, "no orphan inodes to clean up\n");
2390 		return;
2391 	}
2392 
2393 	if (bdev_read_only(sb->s_bdev)) {
2394 		ext4_msg(sb, KERN_ERR, "write access "
2395 			"unavailable, skipping orphan cleanup");
2396 		return;
2397 	}
2398 
2399 	/* Check if feature set would not allow a r/w mount */
2400 	if (!ext4_feature_set_ok(sb, 0)) {
2401 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2402 			 "unknown ROCOMPAT features");
2403 		return;
2404 	}
2405 
2406 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2407 		/* don't clear list on RO mount w/ errors */
2408 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2409 			ext4_msg(sb, KERN_INFO, "Errors on filesystem, "
2410 				  "clearing orphan list.\n");
2411 			es->s_last_orphan = 0;
2412 		}
2413 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2414 		return;
2415 	}
2416 
2417 	if (s_flags & MS_RDONLY) {
2418 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2419 		sb->s_flags &= ~MS_RDONLY;
2420 	}
2421 #ifdef CONFIG_QUOTA
2422 	/* Needed for iput() to work correctly and not trash data */
2423 	sb->s_flags |= MS_ACTIVE;
2424 	/* Turn on quotas so that they are updated correctly */
2425 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2426 		if (EXT4_SB(sb)->s_qf_names[i]) {
2427 			int ret = ext4_quota_on_mount(sb, i);
2428 			if (ret < 0)
2429 				ext4_msg(sb, KERN_ERR,
2430 					"Cannot turn on journaled "
2431 					"quota: error %d", ret);
2432 		}
2433 	}
2434 #endif
2435 
2436 	while (es->s_last_orphan) {
2437 		struct inode *inode;
2438 
2439 		/*
2440 		 * We may have encountered an error during cleanup; if
2441 		 * so, skip the rest.
2442 		 */
2443 		if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2444 			jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2445 			es->s_last_orphan = 0;
2446 			break;
2447 		}
2448 
2449 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2450 		if (IS_ERR(inode)) {
2451 			es->s_last_orphan = 0;
2452 			break;
2453 		}
2454 
2455 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2456 		dquot_initialize(inode);
2457 		if (inode->i_nlink) {
2458 			if (test_opt(sb, DEBUG))
2459 				ext4_msg(sb, KERN_DEBUG,
2460 					"%s: truncating inode %lu to %lld bytes",
2461 					__func__, inode->i_ino, inode->i_size);
2462 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2463 				  inode->i_ino, inode->i_size);
2464 			inode_lock(inode);
2465 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2466 			ret = ext4_truncate(inode);
2467 			if (ret)
2468 				ext4_std_error(inode->i_sb, ret);
2469 			inode_unlock(inode);
2470 			nr_truncates++;
2471 		} else {
2472 			if (test_opt(sb, DEBUG))
2473 				ext4_msg(sb, KERN_DEBUG,
2474 					"%s: deleting unreferenced inode %lu",
2475 					__func__, inode->i_ino);
2476 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2477 				  inode->i_ino);
2478 			nr_orphans++;
2479 		}
2480 		iput(inode);  /* The delete magic happens here! */
2481 	}
2482 
2483 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2484 
2485 	if (nr_orphans)
2486 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2487 		       PLURAL(nr_orphans));
2488 	if (nr_truncates)
2489 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2490 		       PLURAL(nr_truncates));
2491 #ifdef CONFIG_QUOTA
2492 	/* Turn quotas off */
2493 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
2494 		if (sb_dqopt(sb)->files[i])
2495 			dquot_quota_off(sb, i);
2496 	}
2497 #endif
2498 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2499 }
2500 
2501 /*
2502  * Maximal extent format file size.
2503  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2504  * extent format containers, within a sector_t, and within i_blocks
2505  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2506  * so that won't be a limiting factor.
2507  *
2508  * However there is other limiting factor. We do store extents in the form
2509  * of starting block and length, hence the resulting length of the extent
2510  * covering maximum file size must fit into on-disk format containers as
2511  * well. Given that length is always by 1 unit bigger than max unit (because
2512  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2513  *
2514  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2515  */
2516 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2517 {
2518 	loff_t res;
2519 	loff_t upper_limit = MAX_LFS_FILESIZE;
2520 
2521 	/* small i_blocks in vfs inode? */
2522 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2523 		/*
2524 		 * CONFIG_LBDAF is not enabled implies the inode
2525 		 * i_block represent total blocks in 512 bytes
2526 		 * 32 == size of vfs inode i_blocks * 8
2527 		 */
2528 		upper_limit = (1LL << 32) - 1;
2529 
2530 		/* total blocks in file system block size */
2531 		upper_limit >>= (blkbits - 9);
2532 		upper_limit <<= blkbits;
2533 	}
2534 
2535 	/*
2536 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2537 	 * by one fs block, so ee_len can cover the extent of maximum file
2538 	 * size
2539 	 */
2540 	res = (1LL << 32) - 1;
2541 	res <<= blkbits;
2542 
2543 	/* Sanity check against vm- & vfs- imposed limits */
2544 	if (res > upper_limit)
2545 		res = upper_limit;
2546 
2547 	return res;
2548 }
2549 
2550 /*
2551  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2552  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2553  * We need to be 1 filesystem block less than the 2^48 sector limit.
2554  */
2555 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2556 {
2557 	loff_t res = EXT4_NDIR_BLOCKS;
2558 	int meta_blocks;
2559 	loff_t upper_limit;
2560 	/* This is calculated to be the largest file size for a dense, block
2561 	 * mapped file such that the file's total number of 512-byte sectors,
2562 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2563 	 *
2564 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2565 	 * number of 512-byte sectors of the file.
2566 	 */
2567 
2568 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2569 		/*
2570 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2571 		 * the inode i_block field represents total file blocks in
2572 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2573 		 */
2574 		upper_limit = (1LL << 32) - 1;
2575 
2576 		/* total blocks in file system block size */
2577 		upper_limit >>= (bits - 9);
2578 
2579 	} else {
2580 		/*
2581 		 * We use 48 bit ext4_inode i_blocks
2582 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2583 		 * represent total number of blocks in
2584 		 * file system block size
2585 		 */
2586 		upper_limit = (1LL << 48) - 1;
2587 
2588 	}
2589 
2590 	/* indirect blocks */
2591 	meta_blocks = 1;
2592 	/* double indirect blocks */
2593 	meta_blocks += 1 + (1LL << (bits-2));
2594 	/* tripple indirect blocks */
2595 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2596 
2597 	upper_limit -= meta_blocks;
2598 	upper_limit <<= bits;
2599 
2600 	res += 1LL << (bits-2);
2601 	res += 1LL << (2*(bits-2));
2602 	res += 1LL << (3*(bits-2));
2603 	res <<= bits;
2604 	if (res > upper_limit)
2605 		res = upper_limit;
2606 
2607 	if (res > MAX_LFS_FILESIZE)
2608 		res = MAX_LFS_FILESIZE;
2609 
2610 	return res;
2611 }
2612 
2613 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2614 				   ext4_fsblk_t logical_sb_block, int nr)
2615 {
2616 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2617 	ext4_group_t bg, first_meta_bg;
2618 	int has_super = 0;
2619 
2620 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2621 
2622 	if (!ext4_has_feature_meta_bg(sb) || nr < first_meta_bg)
2623 		return logical_sb_block + nr + 1;
2624 	bg = sbi->s_desc_per_block * nr;
2625 	if (ext4_bg_has_super(sb, bg))
2626 		has_super = 1;
2627 
2628 	/*
2629 	 * If we have a meta_bg fs with 1k blocks, group 0's GDT is at
2630 	 * block 2, not 1.  If s_first_data_block == 0 (bigalloc is enabled
2631 	 * on modern mke2fs or blksize > 1k on older mke2fs) then we must
2632 	 * compensate.
2633 	 */
2634 	if (sb->s_blocksize == 1024 && nr == 0 &&
2635 	    le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) == 0)
2636 		has_super++;
2637 
2638 	return (has_super + ext4_group_first_block_no(sb, bg));
2639 }
2640 
2641 /**
2642  * ext4_get_stripe_size: Get the stripe size.
2643  * @sbi: In memory super block info
2644  *
2645  * If we have specified it via mount option, then
2646  * use the mount option value. If the value specified at mount time is
2647  * greater than the blocks per group use the super block value.
2648  * If the super block value is greater than blocks per group return 0.
2649  * Allocator needs it be less than blocks per group.
2650  *
2651  */
2652 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2653 {
2654 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2655 	unsigned long stripe_width =
2656 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2657 	int ret;
2658 
2659 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2660 		ret = sbi->s_stripe;
2661 	else if (stripe_width && stripe_width <= sbi->s_blocks_per_group)
2662 		ret = stripe_width;
2663 	else if (stride && stride <= sbi->s_blocks_per_group)
2664 		ret = stride;
2665 	else
2666 		ret = 0;
2667 
2668 	/*
2669 	 * If the stripe width is 1, this makes no sense and
2670 	 * we set it to 0 to turn off stripe handling code.
2671 	 */
2672 	if (ret <= 1)
2673 		ret = 0;
2674 
2675 	return ret;
2676 }
2677 
2678 /*
2679  * Check whether this filesystem can be mounted based on
2680  * the features present and the RDONLY/RDWR mount requested.
2681  * Returns 1 if this filesystem can be mounted as requested,
2682  * 0 if it cannot be.
2683  */
2684 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2685 {
2686 	if (ext4_has_unknown_ext4_incompat_features(sb)) {
2687 		ext4_msg(sb, KERN_ERR,
2688 			"Couldn't mount because of "
2689 			"unsupported optional features (%x)",
2690 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2691 			~EXT4_FEATURE_INCOMPAT_SUPP));
2692 		return 0;
2693 	}
2694 
2695 	if (readonly)
2696 		return 1;
2697 
2698 	if (ext4_has_feature_readonly(sb)) {
2699 		ext4_msg(sb, KERN_INFO, "filesystem is read-only");
2700 		sb->s_flags |= MS_RDONLY;
2701 		return 1;
2702 	}
2703 
2704 	/* Check that feature set is OK for a read-write mount */
2705 	if (ext4_has_unknown_ext4_ro_compat_features(sb)) {
2706 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2707 			 "unsupported optional features (%x)",
2708 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2709 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2710 		return 0;
2711 	}
2712 	/*
2713 	 * Large file size enabled file system can only be mounted
2714 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2715 	 */
2716 	if (ext4_has_feature_huge_file(sb)) {
2717 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2718 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2719 				 "cannot be mounted RDWR without "
2720 				 "CONFIG_LBDAF");
2721 			return 0;
2722 		}
2723 	}
2724 	if (ext4_has_feature_bigalloc(sb) && !ext4_has_feature_extents(sb)) {
2725 		ext4_msg(sb, KERN_ERR,
2726 			 "Can't support bigalloc feature without "
2727 			 "extents feature\n");
2728 		return 0;
2729 	}
2730 
2731 #ifndef CONFIG_QUOTA
2732 	if (ext4_has_feature_quota(sb) && !readonly) {
2733 		ext4_msg(sb, KERN_ERR,
2734 			 "Filesystem with quota feature cannot be mounted RDWR "
2735 			 "without CONFIG_QUOTA");
2736 		return 0;
2737 	}
2738 	if (ext4_has_feature_project(sb) && !readonly) {
2739 		ext4_msg(sb, KERN_ERR,
2740 			 "Filesystem with project quota feature cannot be mounted RDWR "
2741 			 "without CONFIG_QUOTA");
2742 		return 0;
2743 	}
2744 #endif  /* CONFIG_QUOTA */
2745 	return 1;
2746 }
2747 
2748 /*
2749  * This function is called once a day if we have errors logged
2750  * on the file system
2751  */
2752 static void print_daily_error_info(unsigned long arg)
2753 {
2754 	struct super_block *sb = (struct super_block *) arg;
2755 	struct ext4_sb_info *sbi;
2756 	struct ext4_super_block *es;
2757 
2758 	sbi = EXT4_SB(sb);
2759 	es = sbi->s_es;
2760 
2761 	if (es->s_error_count)
2762 		/* fsck newer than v1.41.13 is needed to clean this condition. */
2763 		ext4_msg(sb, KERN_NOTICE, "error count since last fsck: %u",
2764 			 le32_to_cpu(es->s_error_count));
2765 	if (es->s_first_error_time) {
2766 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at time %u: %.*s:%d",
2767 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2768 		       (int) sizeof(es->s_first_error_func),
2769 		       es->s_first_error_func,
2770 		       le32_to_cpu(es->s_first_error_line));
2771 		if (es->s_first_error_ino)
2772 			printk(KERN_CONT ": inode %u",
2773 			       le32_to_cpu(es->s_first_error_ino));
2774 		if (es->s_first_error_block)
2775 			printk(KERN_CONT ": block %llu", (unsigned long long)
2776 			       le64_to_cpu(es->s_first_error_block));
2777 		printk(KERN_CONT "\n");
2778 	}
2779 	if (es->s_last_error_time) {
2780 		printk(KERN_NOTICE "EXT4-fs (%s): last error at time %u: %.*s:%d",
2781 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2782 		       (int) sizeof(es->s_last_error_func),
2783 		       es->s_last_error_func,
2784 		       le32_to_cpu(es->s_last_error_line));
2785 		if (es->s_last_error_ino)
2786 			printk(KERN_CONT ": inode %u",
2787 			       le32_to_cpu(es->s_last_error_ino));
2788 		if (es->s_last_error_block)
2789 			printk(KERN_CONT ": block %llu", (unsigned long long)
2790 			       le64_to_cpu(es->s_last_error_block));
2791 		printk(KERN_CONT "\n");
2792 	}
2793 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2794 }
2795 
2796 /* Find next suitable group and run ext4_init_inode_table */
2797 static int ext4_run_li_request(struct ext4_li_request *elr)
2798 {
2799 	struct ext4_group_desc *gdp = NULL;
2800 	ext4_group_t group, ngroups;
2801 	struct super_block *sb;
2802 	unsigned long timeout = 0;
2803 	int ret = 0;
2804 
2805 	sb = elr->lr_super;
2806 	ngroups = EXT4_SB(sb)->s_groups_count;
2807 
2808 	for (group = elr->lr_next_group; group < ngroups; group++) {
2809 		gdp = ext4_get_group_desc(sb, group, NULL);
2810 		if (!gdp) {
2811 			ret = 1;
2812 			break;
2813 		}
2814 
2815 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2816 			break;
2817 	}
2818 
2819 	if (group >= ngroups)
2820 		ret = 1;
2821 
2822 	if (!ret) {
2823 		timeout = jiffies;
2824 		ret = ext4_init_inode_table(sb, group,
2825 					    elr->lr_timeout ? 0 : 1);
2826 		if (elr->lr_timeout == 0) {
2827 			timeout = (jiffies - timeout) *
2828 				  elr->lr_sbi->s_li_wait_mult;
2829 			elr->lr_timeout = timeout;
2830 		}
2831 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2832 		elr->lr_next_group = group + 1;
2833 	}
2834 	return ret;
2835 }
2836 
2837 /*
2838  * Remove lr_request from the list_request and free the
2839  * request structure. Should be called with li_list_mtx held
2840  */
2841 static void ext4_remove_li_request(struct ext4_li_request *elr)
2842 {
2843 	struct ext4_sb_info *sbi;
2844 
2845 	if (!elr)
2846 		return;
2847 
2848 	sbi = elr->lr_sbi;
2849 
2850 	list_del(&elr->lr_request);
2851 	sbi->s_li_request = NULL;
2852 	kfree(elr);
2853 }
2854 
2855 static void ext4_unregister_li_request(struct super_block *sb)
2856 {
2857 	mutex_lock(&ext4_li_mtx);
2858 	if (!ext4_li_info) {
2859 		mutex_unlock(&ext4_li_mtx);
2860 		return;
2861 	}
2862 
2863 	mutex_lock(&ext4_li_info->li_list_mtx);
2864 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2865 	mutex_unlock(&ext4_li_info->li_list_mtx);
2866 	mutex_unlock(&ext4_li_mtx);
2867 }
2868 
2869 static struct task_struct *ext4_lazyinit_task;
2870 
2871 /*
2872  * This is the function where ext4lazyinit thread lives. It walks
2873  * through the request list searching for next scheduled filesystem.
2874  * When such a fs is found, run the lazy initialization request
2875  * (ext4_rn_li_request) and keep track of the time spend in this
2876  * function. Based on that time we compute next schedule time of
2877  * the request. When walking through the list is complete, compute
2878  * next waking time and put itself into sleep.
2879  */
2880 static int ext4_lazyinit_thread(void *arg)
2881 {
2882 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2883 	struct list_head *pos, *n;
2884 	struct ext4_li_request *elr;
2885 	unsigned long next_wakeup, cur;
2886 
2887 	BUG_ON(NULL == eli);
2888 
2889 cont_thread:
2890 	while (true) {
2891 		next_wakeup = MAX_JIFFY_OFFSET;
2892 
2893 		mutex_lock(&eli->li_list_mtx);
2894 		if (list_empty(&eli->li_request_list)) {
2895 			mutex_unlock(&eli->li_list_mtx);
2896 			goto exit_thread;
2897 		}
2898 		list_for_each_safe(pos, n, &eli->li_request_list) {
2899 			int err = 0;
2900 			int progress = 0;
2901 			elr = list_entry(pos, struct ext4_li_request,
2902 					 lr_request);
2903 
2904 			if (time_before(jiffies, elr->lr_next_sched)) {
2905 				if (time_before(elr->lr_next_sched, next_wakeup))
2906 					next_wakeup = elr->lr_next_sched;
2907 				continue;
2908 			}
2909 			if (down_read_trylock(&elr->lr_super->s_umount)) {
2910 				if (sb_start_write_trylock(elr->lr_super)) {
2911 					progress = 1;
2912 					/*
2913 					 * We hold sb->s_umount, sb can not
2914 					 * be removed from the list, it is
2915 					 * now safe to drop li_list_mtx
2916 					 */
2917 					mutex_unlock(&eli->li_list_mtx);
2918 					err = ext4_run_li_request(elr);
2919 					sb_end_write(elr->lr_super);
2920 					mutex_lock(&eli->li_list_mtx);
2921 					n = pos->next;
2922 				}
2923 				up_read((&elr->lr_super->s_umount));
2924 			}
2925 			/* error, remove the lazy_init job */
2926 			if (err) {
2927 				ext4_remove_li_request(elr);
2928 				continue;
2929 			}
2930 			if (!progress) {
2931 				elr->lr_next_sched = jiffies +
2932 					(prandom_u32()
2933 					 % (EXT4_DEF_LI_MAX_START_DELAY * HZ));
2934 			}
2935 			if (time_before(elr->lr_next_sched, next_wakeup))
2936 				next_wakeup = elr->lr_next_sched;
2937 		}
2938 		mutex_unlock(&eli->li_list_mtx);
2939 
2940 		try_to_freeze();
2941 
2942 		cur = jiffies;
2943 		if ((time_after_eq(cur, next_wakeup)) ||
2944 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2945 			cond_resched();
2946 			continue;
2947 		}
2948 
2949 		schedule_timeout_interruptible(next_wakeup - cur);
2950 
2951 		if (kthread_should_stop()) {
2952 			ext4_clear_request_list();
2953 			goto exit_thread;
2954 		}
2955 	}
2956 
2957 exit_thread:
2958 	/*
2959 	 * It looks like the request list is empty, but we need
2960 	 * to check it under the li_list_mtx lock, to prevent any
2961 	 * additions into it, and of course we should lock ext4_li_mtx
2962 	 * to atomically free the list and ext4_li_info, because at
2963 	 * this point another ext4 filesystem could be registering
2964 	 * new one.
2965 	 */
2966 	mutex_lock(&ext4_li_mtx);
2967 	mutex_lock(&eli->li_list_mtx);
2968 	if (!list_empty(&eli->li_request_list)) {
2969 		mutex_unlock(&eli->li_list_mtx);
2970 		mutex_unlock(&ext4_li_mtx);
2971 		goto cont_thread;
2972 	}
2973 	mutex_unlock(&eli->li_list_mtx);
2974 	kfree(ext4_li_info);
2975 	ext4_li_info = NULL;
2976 	mutex_unlock(&ext4_li_mtx);
2977 
2978 	return 0;
2979 }
2980 
2981 static void ext4_clear_request_list(void)
2982 {
2983 	struct list_head *pos, *n;
2984 	struct ext4_li_request *elr;
2985 
2986 	mutex_lock(&ext4_li_info->li_list_mtx);
2987 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2988 		elr = list_entry(pos, struct ext4_li_request,
2989 				 lr_request);
2990 		ext4_remove_li_request(elr);
2991 	}
2992 	mutex_unlock(&ext4_li_info->li_list_mtx);
2993 }
2994 
2995 static int ext4_run_lazyinit_thread(void)
2996 {
2997 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2998 					 ext4_li_info, "ext4lazyinit");
2999 	if (IS_ERR(ext4_lazyinit_task)) {
3000 		int err = PTR_ERR(ext4_lazyinit_task);
3001 		ext4_clear_request_list();
3002 		kfree(ext4_li_info);
3003 		ext4_li_info = NULL;
3004 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
3005 				 "initialization thread\n",
3006 				 err);
3007 		return err;
3008 	}
3009 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
3010 	return 0;
3011 }
3012 
3013 /*
3014  * Check whether it make sense to run itable init. thread or not.
3015  * If there is at least one uninitialized inode table, return
3016  * corresponding group number, else the loop goes through all
3017  * groups and return total number of groups.
3018  */
3019 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
3020 {
3021 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
3022 	struct ext4_group_desc *gdp = NULL;
3023 
3024 	for (group = 0; group < ngroups; group++) {
3025 		gdp = ext4_get_group_desc(sb, group, NULL);
3026 		if (!gdp)
3027 			continue;
3028 
3029 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
3030 			break;
3031 	}
3032 
3033 	return group;
3034 }
3035 
3036 static int ext4_li_info_new(void)
3037 {
3038 	struct ext4_lazy_init *eli = NULL;
3039 
3040 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
3041 	if (!eli)
3042 		return -ENOMEM;
3043 
3044 	INIT_LIST_HEAD(&eli->li_request_list);
3045 	mutex_init(&eli->li_list_mtx);
3046 
3047 	eli->li_state |= EXT4_LAZYINIT_QUIT;
3048 
3049 	ext4_li_info = eli;
3050 
3051 	return 0;
3052 }
3053 
3054 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
3055 					    ext4_group_t start)
3056 {
3057 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3058 	struct ext4_li_request *elr;
3059 
3060 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3061 	if (!elr)
3062 		return NULL;
3063 
3064 	elr->lr_super = sb;
3065 	elr->lr_sbi = sbi;
3066 	elr->lr_next_group = start;
3067 
3068 	/*
3069 	 * Randomize first schedule time of the request to
3070 	 * spread the inode table initialization requests
3071 	 * better.
3072 	 */
3073 	elr->lr_next_sched = jiffies + (prandom_u32() %
3074 				(EXT4_DEF_LI_MAX_START_DELAY * HZ));
3075 	return elr;
3076 }
3077 
3078 int ext4_register_li_request(struct super_block *sb,
3079 			     ext4_group_t first_not_zeroed)
3080 {
3081 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3082 	struct ext4_li_request *elr = NULL;
3083 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3084 	int ret = 0;
3085 
3086 	mutex_lock(&ext4_li_mtx);
3087 	if (sbi->s_li_request != NULL) {
3088 		/*
3089 		 * Reset timeout so it can be computed again, because
3090 		 * s_li_wait_mult might have changed.
3091 		 */
3092 		sbi->s_li_request->lr_timeout = 0;
3093 		goto out;
3094 	}
3095 
3096 	if (first_not_zeroed == ngroups ||
3097 	    (sb->s_flags & MS_RDONLY) ||
3098 	    !test_opt(sb, INIT_INODE_TABLE))
3099 		goto out;
3100 
3101 	elr = ext4_li_request_new(sb, first_not_zeroed);
3102 	if (!elr) {
3103 		ret = -ENOMEM;
3104 		goto out;
3105 	}
3106 
3107 	if (NULL == ext4_li_info) {
3108 		ret = ext4_li_info_new();
3109 		if (ret)
3110 			goto out;
3111 	}
3112 
3113 	mutex_lock(&ext4_li_info->li_list_mtx);
3114 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3115 	mutex_unlock(&ext4_li_info->li_list_mtx);
3116 
3117 	sbi->s_li_request = elr;
3118 	/*
3119 	 * set elr to NULL here since it has been inserted to
3120 	 * the request_list and the removal and free of it is
3121 	 * handled by ext4_clear_request_list from now on.
3122 	 */
3123 	elr = NULL;
3124 
3125 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3126 		ret = ext4_run_lazyinit_thread();
3127 		if (ret)
3128 			goto out;
3129 	}
3130 out:
3131 	mutex_unlock(&ext4_li_mtx);
3132 	if (ret)
3133 		kfree(elr);
3134 	return ret;
3135 }
3136 
3137 /*
3138  * We do not need to lock anything since this is called on
3139  * module unload.
3140  */
3141 static void ext4_destroy_lazyinit_thread(void)
3142 {
3143 	/*
3144 	 * If thread exited earlier
3145 	 * there's nothing to be done.
3146 	 */
3147 	if (!ext4_li_info || !ext4_lazyinit_task)
3148 		return;
3149 
3150 	kthread_stop(ext4_lazyinit_task);
3151 }
3152 
3153 static int set_journal_csum_feature_set(struct super_block *sb)
3154 {
3155 	int ret = 1;
3156 	int compat, incompat;
3157 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3158 
3159 	if (ext4_has_metadata_csum(sb)) {
3160 		/* journal checksum v3 */
3161 		compat = 0;
3162 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
3163 	} else {
3164 		/* journal checksum v1 */
3165 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3166 		incompat = 0;
3167 	}
3168 
3169 	jbd2_journal_clear_features(sbi->s_journal,
3170 			JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3171 			JBD2_FEATURE_INCOMPAT_CSUM_V3 |
3172 			JBD2_FEATURE_INCOMPAT_CSUM_V2);
3173 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3174 		ret = jbd2_journal_set_features(sbi->s_journal,
3175 				compat, 0,
3176 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3177 				incompat);
3178 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3179 		ret = jbd2_journal_set_features(sbi->s_journal,
3180 				compat, 0,
3181 				incompat);
3182 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3183 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3184 	} else {
3185 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3186 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3187 	}
3188 
3189 	return ret;
3190 }
3191 
3192 /*
3193  * Note: calculating the overhead so we can be compatible with
3194  * historical BSD practice is quite difficult in the face of
3195  * clusters/bigalloc.  This is because multiple metadata blocks from
3196  * different block group can end up in the same allocation cluster.
3197  * Calculating the exact overhead in the face of clustered allocation
3198  * requires either O(all block bitmaps) in memory or O(number of block
3199  * groups**2) in time.  We will still calculate the superblock for
3200  * older file systems --- and if we come across with a bigalloc file
3201  * system with zero in s_overhead_clusters the estimate will be close to
3202  * correct especially for very large cluster sizes --- but for newer
3203  * file systems, it's better to calculate this figure once at mkfs
3204  * time, and store it in the superblock.  If the superblock value is
3205  * present (even for non-bigalloc file systems), we will use it.
3206  */
3207 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3208 			  char *buf)
3209 {
3210 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3211 	struct ext4_group_desc	*gdp;
3212 	ext4_fsblk_t		first_block, last_block, b;
3213 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3214 	int			s, j, count = 0;
3215 
3216 	if (!ext4_has_feature_bigalloc(sb))
3217 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3218 			sbi->s_itb_per_group + 2);
3219 
3220 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3221 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3222 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3223 	for (i = 0; i < ngroups; i++) {
3224 		gdp = ext4_get_group_desc(sb, i, NULL);
3225 		b = ext4_block_bitmap(sb, gdp);
3226 		if (b >= first_block && b <= last_block) {
3227 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3228 			count++;
3229 		}
3230 		b = ext4_inode_bitmap(sb, gdp);
3231 		if (b >= first_block && b <= last_block) {
3232 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3233 			count++;
3234 		}
3235 		b = ext4_inode_table(sb, gdp);
3236 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3237 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3238 				int c = EXT4_B2C(sbi, b - first_block);
3239 				ext4_set_bit(c, buf);
3240 				count++;
3241 			}
3242 		if (i != grp)
3243 			continue;
3244 		s = 0;
3245 		if (ext4_bg_has_super(sb, grp)) {
3246 			ext4_set_bit(s++, buf);
3247 			count++;
3248 		}
3249 		j = ext4_bg_num_gdb(sb, grp);
3250 		if (s + j > EXT4_BLOCKS_PER_GROUP(sb)) {
3251 			ext4_error(sb, "Invalid number of block group "
3252 				   "descriptor blocks: %d", j);
3253 			j = EXT4_BLOCKS_PER_GROUP(sb) - s;
3254 		}
3255 		count += j;
3256 		for (; j > 0; j--)
3257 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3258 	}
3259 	if (!count)
3260 		return 0;
3261 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3262 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3263 }
3264 
3265 /*
3266  * Compute the overhead and stash it in sbi->s_overhead
3267  */
3268 int ext4_calculate_overhead(struct super_block *sb)
3269 {
3270 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3271 	struct ext4_super_block *es = sbi->s_es;
3272 	struct inode *j_inode;
3273 	unsigned int j_blocks, j_inum = le32_to_cpu(es->s_journal_inum);
3274 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3275 	ext4_fsblk_t overhead = 0;
3276 	char *buf = (char *) get_zeroed_page(GFP_NOFS);
3277 
3278 	if (!buf)
3279 		return -ENOMEM;
3280 
3281 	/*
3282 	 * Compute the overhead (FS structures).  This is constant
3283 	 * for a given filesystem unless the number of block groups
3284 	 * changes so we cache the previous value until it does.
3285 	 */
3286 
3287 	/*
3288 	 * All of the blocks before first_data_block are overhead
3289 	 */
3290 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3291 
3292 	/*
3293 	 * Add the overhead found in each block group
3294 	 */
3295 	for (i = 0; i < ngroups; i++) {
3296 		int blks;
3297 
3298 		blks = count_overhead(sb, i, buf);
3299 		overhead += blks;
3300 		if (blks)
3301 			memset(buf, 0, PAGE_SIZE);
3302 		cond_resched();
3303 	}
3304 
3305 	/*
3306 	 * Add the internal journal blocks whether the journal has been
3307 	 * loaded or not
3308 	 */
3309 	if (sbi->s_journal && !sbi->journal_bdev)
3310 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3311 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal) {
3312 		j_inode = ext4_get_journal_inode(sb, j_inum);
3313 		if (j_inode) {
3314 			j_blocks = j_inode->i_size >> sb->s_blocksize_bits;
3315 			overhead += EXT4_NUM_B2C(sbi, j_blocks);
3316 			iput(j_inode);
3317 		} else {
3318 			ext4_msg(sb, KERN_ERR, "can't get journal size");
3319 		}
3320 	}
3321 	sbi->s_overhead = overhead;
3322 	smp_wmb();
3323 	free_page((unsigned long) buf);
3324 	return 0;
3325 }
3326 
3327 static void ext4_set_resv_clusters(struct super_block *sb)
3328 {
3329 	ext4_fsblk_t resv_clusters;
3330 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3331 
3332 	/*
3333 	 * There's no need to reserve anything when we aren't using extents.
3334 	 * The space estimates are exact, there are no unwritten extents,
3335 	 * hole punching doesn't need new metadata... This is needed especially
3336 	 * to keep ext2/3 backward compatibility.
3337 	 */
3338 	if (!ext4_has_feature_extents(sb))
3339 		return;
3340 	/*
3341 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3342 	 * This should cover the situations where we can not afford to run
3343 	 * out of space like for example punch hole, or converting
3344 	 * unwritten extents in delalloc path. In most cases such
3345 	 * allocation would require 1, or 2 blocks, higher numbers are
3346 	 * very rare.
3347 	 */
3348 	resv_clusters = (ext4_blocks_count(sbi->s_es) >>
3349 			 sbi->s_cluster_bits);
3350 
3351 	do_div(resv_clusters, 50);
3352 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3353 
3354 	atomic64_set(&sbi->s_resv_clusters, resv_clusters);
3355 }
3356 
3357 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3358 {
3359 	char *orig_data = kstrdup(data, GFP_KERNEL);
3360 	struct buffer_head *bh;
3361 	struct ext4_super_block *es = NULL;
3362 	struct ext4_sb_info *sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3363 	ext4_fsblk_t block;
3364 	ext4_fsblk_t sb_block = get_sb_block(&data);
3365 	ext4_fsblk_t logical_sb_block;
3366 	unsigned long offset = 0;
3367 	unsigned long journal_devnum = 0;
3368 	unsigned long def_mount_opts;
3369 	struct inode *root;
3370 	const char *descr;
3371 	int ret = -ENOMEM;
3372 	int blocksize, clustersize;
3373 	unsigned int db_count;
3374 	unsigned int i;
3375 	int needs_recovery, has_huge_files, has_bigalloc;
3376 	__u64 blocks_count;
3377 	int err = 0;
3378 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3379 	ext4_group_t first_not_zeroed;
3380 
3381 	if ((data && !orig_data) || !sbi)
3382 		goto out_free_base;
3383 
3384 	sbi->s_blockgroup_lock =
3385 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3386 	if (!sbi->s_blockgroup_lock)
3387 		goto out_free_base;
3388 
3389 	sb->s_fs_info = sbi;
3390 	sbi->s_sb = sb;
3391 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3392 	sbi->s_sb_block = sb_block;
3393 	if (sb->s_bdev->bd_part)
3394 		sbi->s_sectors_written_start =
3395 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3396 
3397 	/* Cleanup superblock name */
3398 	strreplace(sb->s_id, '/', '!');
3399 
3400 	/* -EINVAL is default */
3401 	ret = -EINVAL;
3402 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3403 	if (!blocksize) {
3404 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3405 		goto out_fail;
3406 	}
3407 
3408 	/*
3409 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3410 	 * block sizes.  We need to calculate the offset from buffer start.
3411 	 */
3412 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3413 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3414 		offset = do_div(logical_sb_block, blocksize);
3415 	} else {
3416 		logical_sb_block = sb_block;
3417 	}
3418 
3419 	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
3420 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3421 		goto out_fail;
3422 	}
3423 	/*
3424 	 * Note: s_es must be initialized as soon as possible because
3425 	 *       some ext4 macro-instructions depend on its value
3426 	 */
3427 	es = (struct ext4_super_block *) (bh->b_data + offset);
3428 	sbi->s_es = es;
3429 	sb->s_magic = le16_to_cpu(es->s_magic);
3430 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3431 		goto cantfind_ext4;
3432 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3433 
3434 	/* Warn if metadata_csum and gdt_csum are both set. */
3435 	if (ext4_has_feature_metadata_csum(sb) &&
3436 	    ext4_has_feature_gdt_csum(sb))
3437 		ext4_warning(sb, "metadata_csum and uninit_bg are "
3438 			     "redundant flags; please run fsck.");
3439 
3440 	/* Check for a known checksum algorithm */
3441 	if (!ext4_verify_csum_type(sb, es)) {
3442 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3443 			 "unknown checksum algorithm.");
3444 		silent = 1;
3445 		goto cantfind_ext4;
3446 	}
3447 
3448 	/* Load the checksum driver */
3449 	if (ext4_has_feature_metadata_csum(sb)) {
3450 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3451 		if (IS_ERR(sbi->s_chksum_driver)) {
3452 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3453 			ret = PTR_ERR(sbi->s_chksum_driver);
3454 			sbi->s_chksum_driver = NULL;
3455 			goto failed_mount;
3456 		}
3457 	}
3458 
3459 	/* Check superblock checksum */
3460 	if (!ext4_superblock_csum_verify(sb, es)) {
3461 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3462 			 "invalid superblock checksum.  Run e2fsck?");
3463 		silent = 1;
3464 		ret = -EFSBADCRC;
3465 		goto cantfind_ext4;
3466 	}
3467 
3468 	/* Precompute checksum seed for all metadata */
3469 	if (ext4_has_feature_csum_seed(sb))
3470 		sbi->s_csum_seed = le32_to_cpu(es->s_checksum_seed);
3471 	else if (ext4_has_metadata_csum(sb))
3472 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3473 					       sizeof(es->s_uuid));
3474 
3475 	/* Set defaults before we parse the mount options */
3476 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3477 	set_opt(sb, INIT_INODE_TABLE);
3478 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3479 		set_opt(sb, DEBUG);
3480 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3481 		set_opt(sb, GRPID);
3482 	if (def_mount_opts & EXT4_DEFM_UID16)
3483 		set_opt(sb, NO_UID32);
3484 	/* xattr user namespace & acls are now defaulted on */
3485 	set_opt(sb, XATTR_USER);
3486 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3487 	set_opt(sb, POSIX_ACL);
3488 #endif
3489 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
3490 	if (ext4_has_metadata_csum(sb))
3491 		set_opt(sb, JOURNAL_CHECKSUM);
3492 
3493 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3494 		set_opt(sb, JOURNAL_DATA);
3495 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3496 		set_opt(sb, ORDERED_DATA);
3497 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3498 		set_opt(sb, WRITEBACK_DATA);
3499 
3500 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3501 		set_opt(sb, ERRORS_PANIC);
3502 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3503 		set_opt(sb, ERRORS_CONT);
3504 	else
3505 		set_opt(sb, ERRORS_RO);
3506 	/* block_validity enabled by default; disable with noblock_validity */
3507 	set_opt(sb, BLOCK_VALIDITY);
3508 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3509 		set_opt(sb, DISCARD);
3510 
3511 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3512 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3513 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3514 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3515 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3516 
3517 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3518 		set_opt(sb, BARRIER);
3519 
3520 	/*
3521 	 * enable delayed allocation by default
3522 	 * Use -o nodelalloc to turn it off
3523 	 */
3524 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3525 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3526 		set_opt(sb, DELALLOC);
3527 
3528 	/*
3529 	 * set default s_li_wait_mult for lazyinit, for the case there is
3530 	 * no mount option specified.
3531 	 */
3532 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3533 
3534 	if (sbi->s_es->s_mount_opts[0]) {
3535 		char *s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
3536 					      sizeof(sbi->s_es->s_mount_opts),
3537 					      GFP_KERNEL);
3538 		if (!s_mount_opts)
3539 			goto failed_mount;
3540 		if (!parse_options(s_mount_opts, sb, &journal_devnum,
3541 				   &journal_ioprio, 0)) {
3542 			ext4_msg(sb, KERN_WARNING,
3543 				 "failed to parse options in superblock: %s",
3544 				 s_mount_opts);
3545 		}
3546 		kfree(s_mount_opts);
3547 	}
3548 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3549 	if (!parse_options((char *) data, sb, &journal_devnum,
3550 			   &journal_ioprio, 0))
3551 		goto failed_mount;
3552 
3553 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3554 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3555 			    "with data=journal disables delayed "
3556 			    "allocation and O_DIRECT support!\n");
3557 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3558 			ext4_msg(sb, KERN_ERR, "can't mount with "
3559 				 "both data=journal and delalloc");
3560 			goto failed_mount;
3561 		}
3562 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3563 			ext4_msg(sb, KERN_ERR, "can't mount with "
3564 				 "both data=journal and dioread_nolock");
3565 			goto failed_mount;
3566 		}
3567 		if (test_opt(sb, DAX)) {
3568 			ext4_msg(sb, KERN_ERR, "can't mount with "
3569 				 "both data=journal and dax");
3570 			goto failed_mount;
3571 		}
3572 		if (ext4_has_feature_encrypt(sb)) {
3573 			ext4_msg(sb, KERN_WARNING,
3574 				 "encrypted files will use data=ordered "
3575 				 "instead of data journaling mode");
3576 		}
3577 		if (test_opt(sb, DELALLOC))
3578 			clear_opt(sb, DELALLOC);
3579 	} else {
3580 		sb->s_iflags |= SB_I_CGROUPWB;
3581 	}
3582 
3583 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3584 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3585 
3586 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3587 	    (ext4_has_compat_features(sb) ||
3588 	     ext4_has_ro_compat_features(sb) ||
3589 	     ext4_has_incompat_features(sb)))
3590 		ext4_msg(sb, KERN_WARNING,
3591 		       "feature flags set on rev 0 fs, "
3592 		       "running e2fsck is recommended");
3593 
3594 	if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
3595 		set_opt2(sb, HURD_COMPAT);
3596 		if (ext4_has_feature_64bit(sb)) {
3597 			ext4_msg(sb, KERN_ERR,
3598 				 "The Hurd can't support 64-bit file systems");
3599 			goto failed_mount;
3600 		}
3601 	}
3602 
3603 	if (IS_EXT2_SB(sb)) {
3604 		if (ext2_feature_set_ok(sb))
3605 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3606 				 "using the ext4 subsystem");
3607 		else {
3608 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3609 				 "to feature incompatibilities");
3610 			goto failed_mount;
3611 		}
3612 	}
3613 
3614 	if (IS_EXT3_SB(sb)) {
3615 		if (ext3_feature_set_ok(sb))
3616 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3617 				 "using the ext4 subsystem");
3618 		else {
3619 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3620 				 "to feature incompatibilities");
3621 			goto failed_mount;
3622 		}
3623 	}
3624 
3625 	/*
3626 	 * Check feature flags regardless of the revision level, since we
3627 	 * previously didn't change the revision level when setting the flags,
3628 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3629 	 */
3630 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3631 		goto failed_mount;
3632 
3633 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3634 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3635 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3636 		ext4_msg(sb, KERN_ERR,
3637 		       "Unsupported filesystem blocksize %d (%d log_block_size)",
3638 			 blocksize, le32_to_cpu(es->s_log_block_size));
3639 		goto failed_mount;
3640 	}
3641 	if (le32_to_cpu(es->s_log_block_size) >
3642 	    (EXT4_MAX_BLOCK_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3643 		ext4_msg(sb, KERN_ERR,
3644 			 "Invalid log block size: %u",
3645 			 le32_to_cpu(es->s_log_block_size));
3646 		goto failed_mount;
3647 	}
3648 
3649 	if (le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) > (blocksize / 4)) {
3650 		ext4_msg(sb, KERN_ERR,
3651 			 "Number of reserved GDT blocks insanely large: %d",
3652 			 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks));
3653 		goto failed_mount;
3654 	}
3655 
3656 	if (sbi->s_mount_opt & EXT4_MOUNT_DAX) {
3657 		err = bdev_dax_supported(sb, blocksize);
3658 		if (err)
3659 			goto failed_mount;
3660 	}
3661 
3662 	if (ext4_has_feature_encrypt(sb) && es->s_encryption_level) {
3663 		ext4_msg(sb, KERN_ERR, "Unsupported encryption level %d",
3664 			 es->s_encryption_level);
3665 		goto failed_mount;
3666 	}
3667 
3668 	if (sb->s_blocksize != blocksize) {
3669 		/* Validate the filesystem blocksize */
3670 		if (!sb_set_blocksize(sb, blocksize)) {
3671 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3672 					blocksize);
3673 			goto failed_mount;
3674 		}
3675 
3676 		brelse(bh);
3677 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3678 		offset = do_div(logical_sb_block, blocksize);
3679 		bh = sb_bread_unmovable(sb, logical_sb_block);
3680 		if (!bh) {
3681 			ext4_msg(sb, KERN_ERR,
3682 			       "Can't read superblock on 2nd try");
3683 			goto failed_mount;
3684 		}
3685 		es = (struct ext4_super_block *)(bh->b_data + offset);
3686 		sbi->s_es = es;
3687 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3688 			ext4_msg(sb, KERN_ERR,
3689 			       "Magic mismatch, very weird!");
3690 			goto failed_mount;
3691 		}
3692 	}
3693 
3694 	has_huge_files = ext4_has_feature_huge_file(sb);
3695 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3696 						      has_huge_files);
3697 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3698 
3699 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3700 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3701 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3702 	} else {
3703 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3704 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3705 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3706 		    (!is_power_of_2(sbi->s_inode_size)) ||
3707 		    (sbi->s_inode_size > blocksize)) {
3708 			ext4_msg(sb, KERN_ERR,
3709 			       "unsupported inode size: %d",
3710 			       sbi->s_inode_size);
3711 			goto failed_mount;
3712 		}
3713 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3714 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3715 	}
3716 
3717 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3718 	if (ext4_has_feature_64bit(sb)) {
3719 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3720 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3721 		    !is_power_of_2(sbi->s_desc_size)) {
3722 			ext4_msg(sb, KERN_ERR,
3723 			       "unsupported descriptor size %lu",
3724 			       sbi->s_desc_size);
3725 			goto failed_mount;
3726 		}
3727 	} else
3728 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3729 
3730 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3731 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3732 
3733 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3734 	if (sbi->s_inodes_per_block == 0)
3735 		goto cantfind_ext4;
3736 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
3737 	    sbi->s_inodes_per_group > blocksize * 8) {
3738 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
3739 			 sbi->s_blocks_per_group);
3740 		goto failed_mount;
3741 	}
3742 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3743 					sbi->s_inodes_per_block;
3744 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3745 	sbi->s_sbh = bh;
3746 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3747 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3748 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3749 
3750 	for (i = 0; i < 4; i++)
3751 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3752 	sbi->s_def_hash_version = es->s_def_hash_version;
3753 	if (ext4_has_feature_dir_index(sb)) {
3754 		i = le32_to_cpu(es->s_flags);
3755 		if (i & EXT2_FLAGS_UNSIGNED_HASH)
3756 			sbi->s_hash_unsigned = 3;
3757 		else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3758 #ifdef __CHAR_UNSIGNED__
3759 			if (!(sb->s_flags & MS_RDONLY))
3760 				es->s_flags |=
3761 					cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3762 			sbi->s_hash_unsigned = 3;
3763 #else
3764 			if (!(sb->s_flags & MS_RDONLY))
3765 				es->s_flags |=
3766 					cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3767 #endif
3768 		}
3769 	}
3770 
3771 	/* Handle clustersize */
3772 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3773 	has_bigalloc = ext4_has_feature_bigalloc(sb);
3774 	if (has_bigalloc) {
3775 		if (clustersize < blocksize) {
3776 			ext4_msg(sb, KERN_ERR,
3777 				 "cluster size (%d) smaller than "
3778 				 "block size (%d)", clustersize, blocksize);
3779 			goto failed_mount;
3780 		}
3781 		if (le32_to_cpu(es->s_log_cluster_size) >
3782 		    (EXT4_MAX_CLUSTER_LOG_SIZE - EXT4_MIN_BLOCK_LOG_SIZE)) {
3783 			ext4_msg(sb, KERN_ERR,
3784 				 "Invalid log cluster size: %u",
3785 				 le32_to_cpu(es->s_log_cluster_size));
3786 			goto failed_mount;
3787 		}
3788 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3789 			le32_to_cpu(es->s_log_block_size);
3790 		sbi->s_clusters_per_group =
3791 			le32_to_cpu(es->s_clusters_per_group);
3792 		if (sbi->s_clusters_per_group > blocksize * 8) {
3793 			ext4_msg(sb, KERN_ERR,
3794 				 "#clusters per group too big: %lu",
3795 				 sbi->s_clusters_per_group);
3796 			goto failed_mount;
3797 		}
3798 		if (sbi->s_blocks_per_group !=
3799 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3800 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3801 				 "clusters per group (%lu) inconsistent",
3802 				 sbi->s_blocks_per_group,
3803 				 sbi->s_clusters_per_group);
3804 			goto failed_mount;
3805 		}
3806 	} else {
3807 		if (clustersize != blocksize) {
3808 			ext4_warning(sb, "fragment/cluster size (%d) != "
3809 				     "block size (%d)", clustersize,
3810 				     blocksize);
3811 			clustersize = blocksize;
3812 		}
3813 		if (sbi->s_blocks_per_group > blocksize * 8) {
3814 			ext4_msg(sb, KERN_ERR,
3815 				 "#blocks per group too big: %lu",
3816 				 sbi->s_blocks_per_group);
3817 			goto failed_mount;
3818 		}
3819 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3820 		sbi->s_cluster_bits = 0;
3821 	}
3822 	sbi->s_cluster_ratio = clustersize / blocksize;
3823 
3824 	/* Do we have standard group size of clustersize * 8 blocks ? */
3825 	if (sbi->s_blocks_per_group == clustersize << 3)
3826 		set_opt2(sb, STD_GROUP_SIZE);
3827 
3828 	/*
3829 	 * Test whether we have more sectors than will fit in sector_t,
3830 	 * and whether the max offset is addressable by the page cache.
3831 	 */
3832 	err = generic_check_addressable(sb->s_blocksize_bits,
3833 					ext4_blocks_count(es));
3834 	if (err) {
3835 		ext4_msg(sb, KERN_ERR, "filesystem"
3836 			 " too large to mount safely on this system");
3837 		if (sizeof(sector_t) < 8)
3838 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3839 		goto failed_mount;
3840 	}
3841 
3842 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3843 		goto cantfind_ext4;
3844 
3845 	/* check blocks count against device size */
3846 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3847 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3848 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3849 		       "exceeds size of device (%llu blocks)",
3850 		       ext4_blocks_count(es), blocks_count);
3851 		goto failed_mount;
3852 	}
3853 
3854 	/*
3855 	 * It makes no sense for the first data block to be beyond the end
3856 	 * of the filesystem.
3857 	 */
3858 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3859 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3860 			 "block %u is beyond end of filesystem (%llu)",
3861 			 le32_to_cpu(es->s_first_data_block),
3862 			 ext4_blocks_count(es));
3863 		goto failed_mount;
3864 	}
3865 	blocks_count = (ext4_blocks_count(es) -
3866 			le32_to_cpu(es->s_first_data_block) +
3867 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3868 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3869 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3870 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3871 		       "(block count %llu, first data block %u, "
3872 		       "blocks per group %lu)", sbi->s_groups_count,
3873 		       ext4_blocks_count(es),
3874 		       le32_to_cpu(es->s_first_data_block),
3875 		       EXT4_BLOCKS_PER_GROUP(sb));
3876 		goto failed_mount;
3877 	}
3878 	sbi->s_groups_count = blocks_count;
3879 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3880 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3881 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3882 		   EXT4_DESC_PER_BLOCK(sb);
3883 	if (ext4_has_feature_meta_bg(sb)) {
3884 		if (le32_to_cpu(es->s_first_meta_bg) > db_count) {
3885 			ext4_msg(sb, KERN_WARNING,
3886 				 "first meta block group too large: %u "
3887 				 "(group descriptor block count %u)",
3888 				 le32_to_cpu(es->s_first_meta_bg), db_count);
3889 			goto failed_mount;
3890 		}
3891 	}
3892 	sbi->s_group_desc = kvmalloc(db_count *
3893 					  sizeof(struct buffer_head *),
3894 					  GFP_KERNEL);
3895 	if (sbi->s_group_desc == NULL) {
3896 		ext4_msg(sb, KERN_ERR, "not enough memory");
3897 		ret = -ENOMEM;
3898 		goto failed_mount;
3899 	}
3900 
3901 	bgl_lock_init(sbi->s_blockgroup_lock);
3902 
3903 	/* Pre-read the descriptors into the buffer cache */
3904 	for (i = 0; i < db_count; i++) {
3905 		block = descriptor_loc(sb, logical_sb_block, i);
3906 		sb_breadahead(sb, block);
3907 	}
3908 
3909 	for (i = 0; i < db_count; i++) {
3910 		block = descriptor_loc(sb, logical_sb_block, i);
3911 		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
3912 		if (!sbi->s_group_desc[i]) {
3913 			ext4_msg(sb, KERN_ERR,
3914 			       "can't read group descriptor %d", i);
3915 			db_count = i;
3916 			goto failed_mount2;
3917 		}
3918 	}
3919 	if (!ext4_check_descriptors(sb, logical_sb_block, &first_not_zeroed)) {
3920 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3921 		ret = -EFSCORRUPTED;
3922 		goto failed_mount2;
3923 	}
3924 
3925 	sbi->s_gdb_count = db_count;
3926 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3927 	spin_lock_init(&sbi->s_next_gen_lock);
3928 
3929 	setup_timer(&sbi->s_err_report, print_daily_error_info,
3930 		(unsigned long) sb);
3931 
3932 	/* Register extent status tree shrinker */
3933 	if (ext4_es_register_shrinker(sbi))
3934 		goto failed_mount3;
3935 
3936 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3937 	sbi->s_extent_max_zeroout_kb = 32;
3938 
3939 	/*
3940 	 * set up enough so that it can read an inode
3941 	 */
3942 	sb->s_op = &ext4_sops;
3943 	sb->s_export_op = &ext4_export_ops;
3944 	sb->s_xattr = ext4_xattr_handlers;
3945 	sb->s_cop = &ext4_cryptops;
3946 #ifdef CONFIG_QUOTA
3947 	sb->dq_op = &ext4_quota_operations;
3948 	if (ext4_has_feature_quota(sb))
3949 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
3950 	else
3951 		sb->s_qcop = &ext4_qctl_operations;
3952 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
3953 #endif
3954 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3955 
3956 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3957 	mutex_init(&sbi->s_orphan_lock);
3958 
3959 	sb->s_root = NULL;
3960 
3961 	needs_recovery = (es->s_last_orphan != 0 ||
3962 			  ext4_has_feature_journal_needs_recovery(sb));
3963 
3964 	if (ext4_has_feature_mmp(sb) && !(sb->s_flags & MS_RDONLY))
3965 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3966 			goto failed_mount3a;
3967 
3968 	/*
3969 	 * The first inode we look at is the journal inode.  Don't try
3970 	 * root first: it may be modified in the journal!
3971 	 */
3972 	if (!test_opt(sb, NOLOAD) && ext4_has_feature_journal(sb)) {
3973 		err = ext4_load_journal(sb, es, journal_devnum);
3974 		if (err)
3975 			goto failed_mount3a;
3976 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3977 		   ext4_has_feature_journal_needs_recovery(sb)) {
3978 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3979 		       "suppressed and not mounted read-only");
3980 		goto failed_mount_wq;
3981 	} else {
3982 		/* Nojournal mode, all journal mount options are illegal */
3983 		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
3984 			ext4_msg(sb, KERN_ERR, "can't mount with "
3985 				 "journal_checksum, fs mounted w/o journal");
3986 			goto failed_mount_wq;
3987 		}
3988 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3989 			ext4_msg(sb, KERN_ERR, "can't mount with "
3990 				 "journal_async_commit, fs mounted w/o journal");
3991 			goto failed_mount_wq;
3992 		}
3993 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
3994 			ext4_msg(sb, KERN_ERR, "can't mount with "
3995 				 "commit=%lu, fs mounted w/o journal",
3996 				 sbi->s_commit_interval / HZ);
3997 			goto failed_mount_wq;
3998 		}
3999 		if (EXT4_MOUNT_DATA_FLAGS &
4000 		    (sbi->s_mount_opt ^ sbi->s_def_mount_opt)) {
4001 			ext4_msg(sb, KERN_ERR, "can't mount with "
4002 				 "data=, fs mounted w/o journal");
4003 			goto failed_mount_wq;
4004 		}
4005 		sbi->s_def_mount_opt &= EXT4_MOUNT_JOURNAL_CHECKSUM;
4006 		clear_opt(sb, JOURNAL_CHECKSUM);
4007 		clear_opt(sb, DATA_FLAGS);
4008 		sbi->s_journal = NULL;
4009 		needs_recovery = 0;
4010 		goto no_journal;
4011 	}
4012 
4013 	if (ext4_has_feature_64bit(sb) &&
4014 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
4015 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
4016 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
4017 		goto failed_mount_wq;
4018 	}
4019 
4020 	if (!set_journal_csum_feature_set(sb)) {
4021 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
4022 			 "feature set");
4023 		goto failed_mount_wq;
4024 	}
4025 
4026 	/* We have now updated the journal if required, so we can
4027 	 * validate the data journaling mode. */
4028 	switch (test_opt(sb, DATA_FLAGS)) {
4029 	case 0:
4030 		/* No mode set, assume a default based on the journal
4031 		 * capabilities: ORDERED_DATA if the journal can
4032 		 * cope, else JOURNAL_DATA
4033 		 */
4034 		if (jbd2_journal_check_available_features
4035 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
4036 			set_opt(sb, ORDERED_DATA);
4037 		else
4038 			set_opt(sb, JOURNAL_DATA);
4039 		break;
4040 
4041 	case EXT4_MOUNT_ORDERED_DATA:
4042 	case EXT4_MOUNT_WRITEBACK_DATA:
4043 		if (!jbd2_journal_check_available_features
4044 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
4045 			ext4_msg(sb, KERN_ERR, "Journal does not support "
4046 			       "requested data journaling mode");
4047 			goto failed_mount_wq;
4048 		}
4049 	default:
4050 		break;
4051 	}
4052 
4053 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA &&
4054 	    test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4055 		ext4_msg(sb, KERN_ERR, "can't mount with "
4056 			"journal_async_commit in data=ordered mode");
4057 		goto failed_mount_wq;
4058 	}
4059 
4060 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4061 
4062 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
4063 
4064 no_journal:
4065 	sbi->s_mb_cache = ext4_xattr_create_cache();
4066 	if (!sbi->s_mb_cache) {
4067 		ext4_msg(sb, KERN_ERR, "Failed to create an mb_cache");
4068 		goto failed_mount_wq;
4069 	}
4070 
4071 	if ((DUMMY_ENCRYPTION_ENABLED(sbi) || ext4_has_feature_encrypt(sb)) &&
4072 	    (blocksize != PAGE_SIZE)) {
4073 		ext4_msg(sb, KERN_ERR,
4074 			 "Unsupported blocksize for fs encryption");
4075 		goto failed_mount_wq;
4076 	}
4077 
4078 	if (DUMMY_ENCRYPTION_ENABLED(sbi) && !(sb->s_flags & MS_RDONLY) &&
4079 	    !ext4_has_feature_encrypt(sb)) {
4080 		ext4_set_feature_encrypt(sb);
4081 		ext4_commit_super(sb, 1);
4082 	}
4083 
4084 	/*
4085 	 * Get the # of file system overhead blocks from the
4086 	 * superblock if present.
4087 	 */
4088 	if (es->s_overhead_clusters)
4089 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
4090 	else {
4091 		err = ext4_calculate_overhead(sb);
4092 		if (err)
4093 			goto failed_mount_wq;
4094 	}
4095 
4096 	/*
4097 	 * The maximum number of concurrent works can be high and
4098 	 * concurrency isn't really necessary.  Limit it to 1.
4099 	 */
4100 	EXT4_SB(sb)->rsv_conversion_wq =
4101 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
4102 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
4103 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
4104 		ret = -ENOMEM;
4105 		goto failed_mount4;
4106 	}
4107 
4108 	/*
4109 	 * The jbd2_journal_load will have done any necessary log recovery,
4110 	 * so we can safely mount the rest of the filesystem now.
4111 	 */
4112 
4113 	root = ext4_iget(sb, EXT4_ROOT_INO);
4114 	if (IS_ERR(root)) {
4115 		ext4_msg(sb, KERN_ERR, "get root inode failed");
4116 		ret = PTR_ERR(root);
4117 		root = NULL;
4118 		goto failed_mount4;
4119 	}
4120 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
4121 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
4122 		iput(root);
4123 		goto failed_mount4;
4124 	}
4125 	sb->s_root = d_make_root(root);
4126 	if (!sb->s_root) {
4127 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
4128 		ret = -ENOMEM;
4129 		goto failed_mount4;
4130 	}
4131 
4132 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
4133 		sb->s_flags |= MS_RDONLY;
4134 
4135 	/* determine the minimum size of new large inodes, if present */
4136 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE &&
4137 	    sbi->s_want_extra_isize == 0) {
4138 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4139 						     EXT4_GOOD_OLD_INODE_SIZE;
4140 		if (ext4_has_feature_extra_isize(sb)) {
4141 			if (sbi->s_want_extra_isize <
4142 			    le16_to_cpu(es->s_want_extra_isize))
4143 				sbi->s_want_extra_isize =
4144 					le16_to_cpu(es->s_want_extra_isize);
4145 			if (sbi->s_want_extra_isize <
4146 			    le16_to_cpu(es->s_min_extra_isize))
4147 				sbi->s_want_extra_isize =
4148 					le16_to_cpu(es->s_min_extra_isize);
4149 		}
4150 	}
4151 	/* Check if enough inode space is available */
4152 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4153 							sbi->s_inode_size) {
4154 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4155 						       EXT4_GOOD_OLD_INODE_SIZE;
4156 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4157 			 "available");
4158 	}
4159 
4160 	ext4_set_resv_clusters(sb);
4161 
4162 	err = ext4_setup_system_zone(sb);
4163 	if (err) {
4164 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4165 			 "zone (%d)", err);
4166 		goto failed_mount4a;
4167 	}
4168 
4169 	ext4_ext_init(sb);
4170 	err = ext4_mb_init(sb);
4171 	if (err) {
4172 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4173 			 err);
4174 		goto failed_mount5;
4175 	}
4176 
4177 	block = ext4_count_free_clusters(sb);
4178 	ext4_free_blocks_count_set(sbi->s_es,
4179 				   EXT4_C2B(sbi, block));
4180 	err = percpu_counter_init(&sbi->s_freeclusters_counter, block,
4181 				  GFP_KERNEL);
4182 	if (!err) {
4183 		unsigned long freei = ext4_count_free_inodes(sb);
4184 		sbi->s_es->s_free_inodes_count = cpu_to_le32(freei);
4185 		err = percpu_counter_init(&sbi->s_freeinodes_counter, freei,
4186 					  GFP_KERNEL);
4187 	}
4188 	if (!err)
4189 		err = percpu_counter_init(&sbi->s_dirs_counter,
4190 					  ext4_count_dirs(sb), GFP_KERNEL);
4191 	if (!err)
4192 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0,
4193 					  GFP_KERNEL);
4194 	if (!err)
4195 		err = percpu_init_rwsem(&sbi->s_journal_flag_rwsem);
4196 
4197 	if (err) {
4198 		ext4_msg(sb, KERN_ERR, "insufficient memory");
4199 		goto failed_mount6;
4200 	}
4201 
4202 	if (ext4_has_feature_flex_bg(sb))
4203 		if (!ext4_fill_flex_info(sb)) {
4204 			ext4_msg(sb, KERN_ERR,
4205 			       "unable to initialize "
4206 			       "flex_bg meta info!");
4207 			goto failed_mount6;
4208 		}
4209 
4210 	err = ext4_register_li_request(sb, first_not_zeroed);
4211 	if (err)
4212 		goto failed_mount6;
4213 
4214 	err = ext4_register_sysfs(sb);
4215 	if (err)
4216 		goto failed_mount7;
4217 
4218 #ifdef CONFIG_QUOTA
4219 	/* Enable quota usage during mount. */
4220 	if (ext4_has_feature_quota(sb) && !(sb->s_flags & MS_RDONLY)) {
4221 		err = ext4_enable_quotas(sb);
4222 		if (err)
4223 			goto failed_mount8;
4224 	}
4225 #endif  /* CONFIG_QUOTA */
4226 
4227 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4228 	ext4_orphan_cleanup(sb, es);
4229 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4230 	if (needs_recovery) {
4231 		ext4_msg(sb, KERN_INFO, "recovery complete");
4232 		ext4_mark_recovery_complete(sb, es);
4233 	}
4234 	if (EXT4_SB(sb)->s_journal) {
4235 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4236 			descr = " journalled data mode";
4237 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4238 			descr = " ordered data mode";
4239 		else
4240 			descr = " writeback data mode";
4241 	} else
4242 		descr = "out journal";
4243 
4244 	if (test_opt(sb, DISCARD)) {
4245 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4246 		if (!blk_queue_discard(q))
4247 			ext4_msg(sb, KERN_WARNING,
4248 				 "mounting with \"discard\" option, but "
4249 				 "the device does not support discard");
4250 	}
4251 
4252 	if (___ratelimit(&ext4_mount_msg_ratelimit, "EXT4-fs mount"))
4253 		ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4254 			 "Opts: %.*s%s%s", descr,
4255 			 (int) sizeof(sbi->s_es->s_mount_opts),
4256 			 sbi->s_es->s_mount_opts,
4257 			 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4258 
4259 	if (es->s_error_count)
4260 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4261 
4262 	/* Enable message ratelimiting. Default is 10 messages per 5 secs. */
4263 	ratelimit_state_init(&sbi->s_err_ratelimit_state, 5 * HZ, 10);
4264 	ratelimit_state_init(&sbi->s_warning_ratelimit_state, 5 * HZ, 10);
4265 	ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10);
4266 
4267 	kfree(orig_data);
4268 	return 0;
4269 
4270 cantfind_ext4:
4271 	if (!silent)
4272 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4273 	goto failed_mount;
4274 
4275 #ifdef CONFIG_QUOTA
4276 failed_mount8:
4277 	ext4_unregister_sysfs(sb);
4278 #endif
4279 failed_mount7:
4280 	ext4_unregister_li_request(sb);
4281 failed_mount6:
4282 	ext4_mb_release(sb);
4283 	if (sbi->s_flex_groups)
4284 		kvfree(sbi->s_flex_groups);
4285 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4286 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4287 	percpu_counter_destroy(&sbi->s_dirs_counter);
4288 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4289 failed_mount5:
4290 	ext4_ext_release(sb);
4291 	ext4_release_system_zone(sb);
4292 failed_mount4a:
4293 	dput(sb->s_root);
4294 	sb->s_root = NULL;
4295 failed_mount4:
4296 	ext4_msg(sb, KERN_ERR, "mount failed");
4297 	if (EXT4_SB(sb)->rsv_conversion_wq)
4298 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4299 failed_mount_wq:
4300 	if (sbi->s_mb_cache) {
4301 		ext4_xattr_destroy_cache(sbi->s_mb_cache);
4302 		sbi->s_mb_cache = NULL;
4303 	}
4304 	if (sbi->s_journal) {
4305 		jbd2_journal_destroy(sbi->s_journal);
4306 		sbi->s_journal = NULL;
4307 	}
4308 failed_mount3a:
4309 	ext4_es_unregister_shrinker(sbi);
4310 failed_mount3:
4311 	del_timer_sync(&sbi->s_err_report);
4312 	if (sbi->s_mmp_tsk)
4313 		kthread_stop(sbi->s_mmp_tsk);
4314 failed_mount2:
4315 	for (i = 0; i < db_count; i++)
4316 		brelse(sbi->s_group_desc[i]);
4317 	kvfree(sbi->s_group_desc);
4318 failed_mount:
4319 	if (sbi->s_chksum_driver)
4320 		crypto_free_shash(sbi->s_chksum_driver);
4321 #ifdef CONFIG_QUOTA
4322 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4323 		kfree(sbi->s_qf_names[i]);
4324 #endif
4325 	ext4_blkdev_remove(sbi);
4326 	brelse(bh);
4327 out_fail:
4328 	sb->s_fs_info = NULL;
4329 	kfree(sbi->s_blockgroup_lock);
4330 out_free_base:
4331 	kfree(sbi);
4332 	kfree(orig_data);
4333 	return err ? err : ret;
4334 }
4335 
4336 /*
4337  * Setup any per-fs journal parameters now.  We'll do this both on
4338  * initial mount, once the journal has been initialised but before we've
4339  * done any recovery; and again on any subsequent remount.
4340  */
4341 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4342 {
4343 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4344 
4345 	journal->j_commit_interval = sbi->s_commit_interval;
4346 	journal->j_min_batch_time = sbi->s_min_batch_time;
4347 	journal->j_max_batch_time = sbi->s_max_batch_time;
4348 
4349 	write_lock(&journal->j_state_lock);
4350 	if (test_opt(sb, BARRIER))
4351 		journal->j_flags |= JBD2_BARRIER;
4352 	else
4353 		journal->j_flags &= ~JBD2_BARRIER;
4354 	if (test_opt(sb, DATA_ERR_ABORT))
4355 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4356 	else
4357 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4358 	write_unlock(&journal->j_state_lock);
4359 }
4360 
4361 static struct inode *ext4_get_journal_inode(struct super_block *sb,
4362 					     unsigned int journal_inum)
4363 {
4364 	struct inode *journal_inode;
4365 
4366 	/*
4367 	 * Test for the existence of a valid inode on disk.  Bad things
4368 	 * happen if we iget() an unused inode, as the subsequent iput()
4369 	 * will try to delete it.
4370 	 */
4371 	journal_inode = ext4_iget(sb, journal_inum);
4372 	if (IS_ERR(journal_inode)) {
4373 		ext4_msg(sb, KERN_ERR, "no journal found");
4374 		return NULL;
4375 	}
4376 	if (!journal_inode->i_nlink) {
4377 		make_bad_inode(journal_inode);
4378 		iput(journal_inode);
4379 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4380 		return NULL;
4381 	}
4382 
4383 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4384 		  journal_inode, journal_inode->i_size);
4385 	if (!S_ISREG(journal_inode->i_mode)) {
4386 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4387 		iput(journal_inode);
4388 		return NULL;
4389 	}
4390 	return journal_inode;
4391 }
4392 
4393 static journal_t *ext4_get_journal(struct super_block *sb,
4394 				   unsigned int journal_inum)
4395 {
4396 	struct inode *journal_inode;
4397 	journal_t *journal;
4398 
4399 	BUG_ON(!ext4_has_feature_journal(sb));
4400 
4401 	journal_inode = ext4_get_journal_inode(sb, journal_inum);
4402 	if (!journal_inode)
4403 		return NULL;
4404 
4405 	journal = jbd2_journal_init_inode(journal_inode);
4406 	if (!journal) {
4407 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4408 		iput(journal_inode);
4409 		return NULL;
4410 	}
4411 	journal->j_private = sb;
4412 	ext4_init_journal_params(sb, journal);
4413 	return journal;
4414 }
4415 
4416 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4417 				       dev_t j_dev)
4418 {
4419 	struct buffer_head *bh;
4420 	journal_t *journal;
4421 	ext4_fsblk_t start;
4422 	ext4_fsblk_t len;
4423 	int hblock, blocksize;
4424 	ext4_fsblk_t sb_block;
4425 	unsigned long offset;
4426 	struct ext4_super_block *es;
4427 	struct block_device *bdev;
4428 
4429 	BUG_ON(!ext4_has_feature_journal(sb));
4430 
4431 	bdev = ext4_blkdev_get(j_dev, sb);
4432 	if (bdev == NULL)
4433 		return NULL;
4434 
4435 	blocksize = sb->s_blocksize;
4436 	hblock = bdev_logical_block_size(bdev);
4437 	if (blocksize < hblock) {
4438 		ext4_msg(sb, KERN_ERR,
4439 			"blocksize too small for journal device");
4440 		goto out_bdev;
4441 	}
4442 
4443 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4444 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4445 	set_blocksize(bdev, blocksize);
4446 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4447 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4448 		       "external journal");
4449 		goto out_bdev;
4450 	}
4451 
4452 	es = (struct ext4_super_block *) (bh->b_data + offset);
4453 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4454 	    !(le32_to_cpu(es->s_feature_incompat) &
4455 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4456 		ext4_msg(sb, KERN_ERR, "external journal has "
4457 					"bad superblock");
4458 		brelse(bh);
4459 		goto out_bdev;
4460 	}
4461 
4462 	if ((le32_to_cpu(es->s_feature_ro_compat) &
4463 	     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
4464 	    es->s_checksum != ext4_superblock_csum(sb, es)) {
4465 		ext4_msg(sb, KERN_ERR, "external journal has "
4466 				       "corrupt superblock");
4467 		brelse(bh);
4468 		goto out_bdev;
4469 	}
4470 
4471 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4472 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4473 		brelse(bh);
4474 		goto out_bdev;
4475 	}
4476 
4477 	len = ext4_blocks_count(es);
4478 	start = sb_block + 1;
4479 	brelse(bh);	/* we're done with the superblock */
4480 
4481 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4482 					start, len, blocksize);
4483 	if (!journal) {
4484 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4485 		goto out_bdev;
4486 	}
4487 	journal->j_private = sb;
4488 	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4489 	wait_on_buffer(journal->j_sb_buffer);
4490 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4491 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4492 		goto out_journal;
4493 	}
4494 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4495 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4496 					"user (unsupported) - %d",
4497 			be32_to_cpu(journal->j_superblock->s_nr_users));
4498 		goto out_journal;
4499 	}
4500 	EXT4_SB(sb)->journal_bdev = bdev;
4501 	ext4_init_journal_params(sb, journal);
4502 	return journal;
4503 
4504 out_journal:
4505 	jbd2_journal_destroy(journal);
4506 out_bdev:
4507 	ext4_blkdev_put(bdev);
4508 	return NULL;
4509 }
4510 
4511 static int ext4_load_journal(struct super_block *sb,
4512 			     struct ext4_super_block *es,
4513 			     unsigned long journal_devnum)
4514 {
4515 	journal_t *journal;
4516 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4517 	dev_t journal_dev;
4518 	int err = 0;
4519 	int really_read_only;
4520 
4521 	BUG_ON(!ext4_has_feature_journal(sb));
4522 
4523 	if (journal_devnum &&
4524 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4525 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4526 			"numbers have changed");
4527 		journal_dev = new_decode_dev(journal_devnum);
4528 	} else
4529 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4530 
4531 	really_read_only = bdev_read_only(sb->s_bdev);
4532 
4533 	/*
4534 	 * Are we loading a blank journal or performing recovery after a
4535 	 * crash?  For recovery, we need to check in advance whether we
4536 	 * can get read-write access to the device.
4537 	 */
4538 	if (ext4_has_feature_journal_needs_recovery(sb)) {
4539 		if (sb->s_flags & MS_RDONLY) {
4540 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4541 					"required on readonly filesystem");
4542 			if (really_read_only) {
4543 				ext4_msg(sb, KERN_ERR, "write access "
4544 					"unavailable, cannot proceed");
4545 				return -EROFS;
4546 			}
4547 			ext4_msg(sb, KERN_INFO, "write access will "
4548 			       "be enabled during recovery");
4549 		}
4550 	}
4551 
4552 	if (journal_inum && journal_dev) {
4553 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4554 		       "and inode journals!");
4555 		return -EINVAL;
4556 	}
4557 
4558 	if (journal_inum) {
4559 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4560 			return -EINVAL;
4561 	} else {
4562 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4563 			return -EINVAL;
4564 	}
4565 
4566 	if (!(journal->j_flags & JBD2_BARRIER))
4567 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4568 
4569 	if (!ext4_has_feature_journal_needs_recovery(sb))
4570 		err = jbd2_journal_wipe(journal, !really_read_only);
4571 	if (!err) {
4572 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4573 		if (save)
4574 			memcpy(save, ((char *) es) +
4575 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4576 		err = jbd2_journal_load(journal);
4577 		if (save)
4578 			memcpy(((char *) es) + EXT4_S_ERR_START,
4579 			       save, EXT4_S_ERR_LEN);
4580 		kfree(save);
4581 	}
4582 
4583 	if (err) {
4584 		ext4_msg(sb, KERN_ERR, "error loading journal");
4585 		jbd2_journal_destroy(journal);
4586 		return err;
4587 	}
4588 
4589 	EXT4_SB(sb)->s_journal = journal;
4590 	ext4_clear_journal_err(sb, es);
4591 
4592 	if (!really_read_only && journal_devnum &&
4593 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4594 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4595 
4596 		/* Make sure we flush the recovery flag to disk. */
4597 		ext4_commit_super(sb, 1);
4598 	}
4599 
4600 	return 0;
4601 }
4602 
4603 static int ext4_commit_super(struct super_block *sb, int sync)
4604 {
4605 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4606 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4607 	int error = 0;
4608 
4609 	if (!sbh || block_device_ejected(sb))
4610 		return error;
4611 	/*
4612 	 * If the file system is mounted read-only, don't update the
4613 	 * superblock write time.  This avoids updating the superblock
4614 	 * write time when we are mounting the root file system
4615 	 * read/only but we need to replay the journal; at that point,
4616 	 * for people who are east of GMT and who make their clock
4617 	 * tick in localtime for Windows bug-for-bug compatibility,
4618 	 * the clock is set in the future, and this will cause e2fsck
4619 	 * to complain and force a full file system check.
4620 	 */
4621 	if (!(sb->s_flags & MS_RDONLY))
4622 		es->s_wtime = cpu_to_le32(get_seconds());
4623 	if (sb->s_bdev->bd_part)
4624 		es->s_kbytes_written =
4625 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4626 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4627 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4628 	else
4629 		es->s_kbytes_written =
4630 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4631 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
4632 		ext4_free_blocks_count_set(es,
4633 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4634 				&EXT4_SB(sb)->s_freeclusters_counter)));
4635 	if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeinodes_counter))
4636 		es->s_free_inodes_count =
4637 			cpu_to_le32(percpu_counter_sum_positive(
4638 				&EXT4_SB(sb)->s_freeinodes_counter));
4639 	BUFFER_TRACE(sbh, "marking dirty");
4640 	ext4_superblock_csum_set(sb);
4641 	if (sync)
4642 		lock_buffer(sbh);
4643 	if (buffer_write_io_error(sbh)) {
4644 		/*
4645 		 * Oh, dear.  A previous attempt to write the
4646 		 * superblock failed.  This could happen because the
4647 		 * USB device was yanked out.  Or it could happen to
4648 		 * be a transient write error and maybe the block will
4649 		 * be remapped.  Nothing we can do but to retry the
4650 		 * write and hope for the best.
4651 		 */
4652 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4653 		       "superblock detected");
4654 		clear_buffer_write_io_error(sbh);
4655 		set_buffer_uptodate(sbh);
4656 	}
4657 	mark_buffer_dirty(sbh);
4658 	if (sync) {
4659 		unlock_buffer(sbh);
4660 		error = __sync_dirty_buffer(sbh,
4661 			REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
4662 		if (error)
4663 			return error;
4664 
4665 		error = buffer_write_io_error(sbh);
4666 		if (error) {
4667 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4668 			       "superblock");
4669 			clear_buffer_write_io_error(sbh);
4670 			set_buffer_uptodate(sbh);
4671 		}
4672 	}
4673 	return error;
4674 }
4675 
4676 /*
4677  * Have we just finished recovery?  If so, and if we are mounting (or
4678  * remounting) the filesystem readonly, then we will end up with a
4679  * consistent fs on disk.  Record that fact.
4680  */
4681 static void ext4_mark_recovery_complete(struct super_block *sb,
4682 					struct ext4_super_block *es)
4683 {
4684 	journal_t *journal = EXT4_SB(sb)->s_journal;
4685 
4686 	if (!ext4_has_feature_journal(sb)) {
4687 		BUG_ON(journal != NULL);
4688 		return;
4689 	}
4690 	jbd2_journal_lock_updates(journal);
4691 	if (jbd2_journal_flush(journal) < 0)
4692 		goto out;
4693 
4694 	if (ext4_has_feature_journal_needs_recovery(sb) &&
4695 	    sb->s_flags & MS_RDONLY) {
4696 		ext4_clear_feature_journal_needs_recovery(sb);
4697 		ext4_commit_super(sb, 1);
4698 	}
4699 
4700 out:
4701 	jbd2_journal_unlock_updates(journal);
4702 }
4703 
4704 /*
4705  * If we are mounting (or read-write remounting) a filesystem whose journal
4706  * has recorded an error from a previous lifetime, move that error to the
4707  * main filesystem now.
4708  */
4709 static void ext4_clear_journal_err(struct super_block *sb,
4710 				   struct ext4_super_block *es)
4711 {
4712 	journal_t *journal;
4713 	int j_errno;
4714 	const char *errstr;
4715 
4716 	BUG_ON(!ext4_has_feature_journal(sb));
4717 
4718 	journal = EXT4_SB(sb)->s_journal;
4719 
4720 	/*
4721 	 * Now check for any error status which may have been recorded in the
4722 	 * journal by a prior ext4_error() or ext4_abort()
4723 	 */
4724 
4725 	j_errno = jbd2_journal_errno(journal);
4726 	if (j_errno) {
4727 		char nbuf[16];
4728 
4729 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4730 		ext4_warning(sb, "Filesystem error recorded "
4731 			     "from previous mount: %s", errstr);
4732 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4733 
4734 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4735 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4736 		ext4_commit_super(sb, 1);
4737 
4738 		jbd2_journal_clear_err(journal);
4739 		jbd2_journal_update_sb_errno(journal);
4740 	}
4741 }
4742 
4743 /*
4744  * Force the running and committing transactions to commit,
4745  * and wait on the commit.
4746  */
4747 int ext4_force_commit(struct super_block *sb)
4748 {
4749 	journal_t *journal;
4750 
4751 	if (sb->s_flags & MS_RDONLY)
4752 		return 0;
4753 
4754 	journal = EXT4_SB(sb)->s_journal;
4755 	return ext4_journal_force_commit(journal);
4756 }
4757 
4758 static int ext4_sync_fs(struct super_block *sb, int wait)
4759 {
4760 	int ret = 0;
4761 	tid_t target;
4762 	bool needs_barrier = false;
4763 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4764 
4765 	if (unlikely(ext4_forced_shutdown(EXT4_SB(sb))))
4766 		return 0;
4767 
4768 	trace_ext4_sync_fs(sb, wait);
4769 	flush_workqueue(sbi->rsv_conversion_wq);
4770 	/*
4771 	 * Writeback quota in non-journalled quota case - journalled quota has
4772 	 * no dirty dquots
4773 	 */
4774 	dquot_writeback_dquots(sb, -1);
4775 	/*
4776 	 * Data writeback is possible w/o journal transaction, so barrier must
4777 	 * being sent at the end of the function. But we can skip it if
4778 	 * transaction_commit will do it for us.
4779 	 */
4780 	if (sbi->s_journal) {
4781 		target = jbd2_get_latest_transaction(sbi->s_journal);
4782 		if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4783 		    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4784 			needs_barrier = true;
4785 
4786 		if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4787 			if (wait)
4788 				ret = jbd2_log_wait_commit(sbi->s_journal,
4789 							   target);
4790 		}
4791 	} else if (wait && test_opt(sb, BARRIER))
4792 		needs_barrier = true;
4793 	if (needs_barrier) {
4794 		int err;
4795 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4796 		if (!ret)
4797 			ret = err;
4798 	}
4799 
4800 	return ret;
4801 }
4802 
4803 /*
4804  * LVM calls this function before a (read-only) snapshot is created.  This
4805  * gives us a chance to flush the journal completely and mark the fs clean.
4806  *
4807  * Note that only this function cannot bring a filesystem to be in a clean
4808  * state independently. It relies on upper layer to stop all data & metadata
4809  * modifications.
4810  */
4811 static int ext4_freeze(struct super_block *sb)
4812 {
4813 	int error = 0;
4814 	journal_t *journal;
4815 
4816 	if (sb->s_flags & MS_RDONLY)
4817 		return 0;
4818 
4819 	journal = EXT4_SB(sb)->s_journal;
4820 
4821 	if (journal) {
4822 		/* Now we set up the journal barrier. */
4823 		jbd2_journal_lock_updates(journal);
4824 
4825 		/*
4826 		 * Don't clear the needs_recovery flag if we failed to
4827 		 * flush the journal.
4828 		 */
4829 		error = jbd2_journal_flush(journal);
4830 		if (error < 0)
4831 			goto out;
4832 
4833 		/* Journal blocked and flushed, clear needs_recovery flag. */
4834 		ext4_clear_feature_journal_needs_recovery(sb);
4835 	}
4836 
4837 	error = ext4_commit_super(sb, 1);
4838 out:
4839 	if (journal)
4840 		/* we rely on upper layer to stop further updates */
4841 		jbd2_journal_unlock_updates(journal);
4842 	return error;
4843 }
4844 
4845 /*
4846  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4847  * flag here, even though the filesystem is not technically dirty yet.
4848  */
4849 static int ext4_unfreeze(struct super_block *sb)
4850 {
4851 	if ((sb->s_flags & MS_RDONLY) || ext4_forced_shutdown(EXT4_SB(sb)))
4852 		return 0;
4853 
4854 	if (EXT4_SB(sb)->s_journal) {
4855 		/* Reset the needs_recovery flag before the fs is unlocked. */
4856 		ext4_set_feature_journal_needs_recovery(sb);
4857 	}
4858 
4859 	ext4_commit_super(sb, 1);
4860 	return 0;
4861 }
4862 
4863 /*
4864  * Structure to save mount options for ext4_remount's benefit
4865  */
4866 struct ext4_mount_options {
4867 	unsigned long s_mount_opt;
4868 	unsigned long s_mount_opt2;
4869 	kuid_t s_resuid;
4870 	kgid_t s_resgid;
4871 	unsigned long s_commit_interval;
4872 	u32 s_min_batch_time, s_max_batch_time;
4873 #ifdef CONFIG_QUOTA
4874 	int s_jquota_fmt;
4875 	char *s_qf_names[EXT4_MAXQUOTAS];
4876 #endif
4877 };
4878 
4879 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4880 {
4881 	struct ext4_super_block *es;
4882 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4883 	unsigned long old_sb_flags;
4884 	struct ext4_mount_options old_opts;
4885 	int enable_quota = 0;
4886 	ext4_group_t g;
4887 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4888 	int err = 0;
4889 #ifdef CONFIG_QUOTA
4890 	int i, j;
4891 #endif
4892 	char *orig_data = kstrdup(data, GFP_KERNEL);
4893 
4894 	/* Store the original options */
4895 	old_sb_flags = sb->s_flags;
4896 	old_opts.s_mount_opt = sbi->s_mount_opt;
4897 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4898 	old_opts.s_resuid = sbi->s_resuid;
4899 	old_opts.s_resgid = sbi->s_resgid;
4900 	old_opts.s_commit_interval = sbi->s_commit_interval;
4901 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4902 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4903 #ifdef CONFIG_QUOTA
4904 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4905 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
4906 		if (sbi->s_qf_names[i]) {
4907 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4908 							 GFP_KERNEL);
4909 			if (!old_opts.s_qf_names[i]) {
4910 				for (j = 0; j < i; j++)
4911 					kfree(old_opts.s_qf_names[j]);
4912 				kfree(orig_data);
4913 				return -ENOMEM;
4914 			}
4915 		} else
4916 			old_opts.s_qf_names[i] = NULL;
4917 #endif
4918 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4919 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4920 
4921 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4922 		err = -EINVAL;
4923 		goto restore_opts;
4924 	}
4925 
4926 	if ((old_opts.s_mount_opt & EXT4_MOUNT_JOURNAL_CHECKSUM) ^
4927 	    test_opt(sb, JOURNAL_CHECKSUM)) {
4928 		ext4_msg(sb, KERN_ERR, "changing journal_checksum "
4929 			 "during remount not supported; ignoring");
4930 		sbi->s_mount_opt ^= EXT4_MOUNT_JOURNAL_CHECKSUM;
4931 	}
4932 
4933 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4934 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4935 			ext4_msg(sb, KERN_ERR, "can't mount with "
4936 				 "both data=journal and delalloc");
4937 			err = -EINVAL;
4938 			goto restore_opts;
4939 		}
4940 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4941 			ext4_msg(sb, KERN_ERR, "can't mount with "
4942 				 "both data=journal and dioread_nolock");
4943 			err = -EINVAL;
4944 			goto restore_opts;
4945 		}
4946 		if (test_opt(sb, DAX)) {
4947 			ext4_msg(sb, KERN_ERR, "can't mount with "
4948 				 "both data=journal and dax");
4949 			err = -EINVAL;
4950 			goto restore_opts;
4951 		}
4952 	} else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA) {
4953 		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
4954 			ext4_msg(sb, KERN_ERR, "can't mount with "
4955 				"journal_async_commit in data=ordered mode");
4956 			err = -EINVAL;
4957 			goto restore_opts;
4958 		}
4959 	}
4960 
4961 	if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX) {
4962 		ext4_msg(sb, KERN_WARNING, "warning: refusing change of "
4963 			"dax flag with busy inodes while remounting");
4964 		sbi->s_mount_opt ^= EXT4_MOUNT_DAX;
4965 	}
4966 
4967 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4968 		ext4_abort(sb, "Abort forced by user");
4969 
4970 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4971 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4972 
4973 	es = sbi->s_es;
4974 
4975 	if (sbi->s_journal) {
4976 		ext4_init_journal_params(sb, sbi->s_journal);
4977 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4978 	}
4979 
4980 	if (*flags & MS_LAZYTIME)
4981 		sb->s_flags |= MS_LAZYTIME;
4982 
4983 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4984 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4985 			err = -EROFS;
4986 			goto restore_opts;
4987 		}
4988 
4989 		if (*flags & MS_RDONLY) {
4990 			err = sync_filesystem(sb);
4991 			if (err < 0)
4992 				goto restore_opts;
4993 			err = dquot_suspend(sb, -1);
4994 			if (err < 0)
4995 				goto restore_opts;
4996 
4997 			/*
4998 			 * First of all, the unconditional stuff we have to do
4999 			 * to disable replay of the journal when we next remount
5000 			 */
5001 			sb->s_flags |= MS_RDONLY;
5002 
5003 			/*
5004 			 * OK, test if we are remounting a valid rw partition
5005 			 * readonly, and if so set the rdonly flag and then
5006 			 * mark the partition as valid again.
5007 			 */
5008 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
5009 			    (sbi->s_mount_state & EXT4_VALID_FS))
5010 				es->s_state = cpu_to_le16(sbi->s_mount_state);
5011 
5012 			if (sbi->s_journal)
5013 				ext4_mark_recovery_complete(sb, es);
5014 		} else {
5015 			/* Make sure we can mount this feature set readwrite */
5016 			if (ext4_has_feature_readonly(sb) ||
5017 			    !ext4_feature_set_ok(sb, 0)) {
5018 				err = -EROFS;
5019 				goto restore_opts;
5020 			}
5021 			/*
5022 			 * Make sure the group descriptor checksums
5023 			 * are sane.  If they aren't, refuse to remount r/w.
5024 			 */
5025 			for (g = 0; g < sbi->s_groups_count; g++) {
5026 				struct ext4_group_desc *gdp =
5027 					ext4_get_group_desc(sb, g, NULL);
5028 
5029 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
5030 					ext4_msg(sb, KERN_ERR,
5031 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
5032 		g, le16_to_cpu(ext4_group_desc_csum(sb, g, gdp)),
5033 					       le16_to_cpu(gdp->bg_checksum));
5034 					err = -EFSBADCRC;
5035 					goto restore_opts;
5036 				}
5037 			}
5038 
5039 			/*
5040 			 * If we have an unprocessed orphan list hanging
5041 			 * around from a previously readonly bdev mount,
5042 			 * require a full umount/remount for now.
5043 			 */
5044 			if (es->s_last_orphan) {
5045 				ext4_msg(sb, KERN_WARNING, "Couldn't "
5046 				       "remount RDWR because of unprocessed "
5047 				       "orphan inode list.  Please "
5048 				       "umount/remount instead");
5049 				err = -EINVAL;
5050 				goto restore_opts;
5051 			}
5052 
5053 			/*
5054 			 * Mounting a RDONLY partition read-write, so reread
5055 			 * and store the current valid flag.  (It may have
5056 			 * been changed by e2fsck since we originally mounted
5057 			 * the partition.)
5058 			 */
5059 			if (sbi->s_journal)
5060 				ext4_clear_journal_err(sb, es);
5061 			sbi->s_mount_state = le16_to_cpu(es->s_state);
5062 			if (!ext4_setup_super(sb, es, 0))
5063 				sb->s_flags &= ~MS_RDONLY;
5064 			if (ext4_has_feature_mmp(sb))
5065 				if (ext4_multi_mount_protect(sb,
5066 						le64_to_cpu(es->s_mmp_block))) {
5067 					err = -EROFS;
5068 					goto restore_opts;
5069 				}
5070 			enable_quota = 1;
5071 		}
5072 	}
5073 
5074 	/*
5075 	 * Reinitialize lazy itable initialization thread based on
5076 	 * current settings
5077 	 */
5078 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
5079 		ext4_unregister_li_request(sb);
5080 	else {
5081 		ext4_group_t first_not_zeroed;
5082 		first_not_zeroed = ext4_has_uninit_itable(sb);
5083 		ext4_register_li_request(sb, first_not_zeroed);
5084 	}
5085 
5086 	ext4_setup_system_zone(sb);
5087 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
5088 		ext4_commit_super(sb, 1);
5089 
5090 #ifdef CONFIG_QUOTA
5091 	/* Release old quota file names */
5092 	for (i = 0; i < EXT4_MAXQUOTAS; i++)
5093 		kfree(old_opts.s_qf_names[i]);
5094 	if (enable_quota) {
5095 		if (sb_any_quota_suspended(sb))
5096 			dquot_resume(sb, -1);
5097 		else if (ext4_has_feature_quota(sb)) {
5098 			err = ext4_enable_quotas(sb);
5099 			if (err)
5100 				goto restore_opts;
5101 		}
5102 	}
5103 #endif
5104 
5105 	*flags = (*flags & ~MS_LAZYTIME) | (sb->s_flags & MS_LAZYTIME);
5106 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
5107 	kfree(orig_data);
5108 	return 0;
5109 
5110 restore_opts:
5111 	sb->s_flags = old_sb_flags;
5112 	sbi->s_mount_opt = old_opts.s_mount_opt;
5113 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
5114 	sbi->s_resuid = old_opts.s_resuid;
5115 	sbi->s_resgid = old_opts.s_resgid;
5116 	sbi->s_commit_interval = old_opts.s_commit_interval;
5117 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
5118 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
5119 #ifdef CONFIG_QUOTA
5120 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
5121 	for (i = 0; i < EXT4_MAXQUOTAS; i++) {
5122 		kfree(sbi->s_qf_names[i]);
5123 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
5124 	}
5125 #endif
5126 	kfree(orig_data);
5127 	return err;
5128 }
5129 
5130 #ifdef CONFIG_QUOTA
5131 static int ext4_statfs_project(struct super_block *sb,
5132 			       kprojid_t projid, struct kstatfs *buf)
5133 {
5134 	struct kqid qid;
5135 	struct dquot *dquot;
5136 	u64 limit;
5137 	u64 curblock;
5138 
5139 	qid = make_kqid_projid(projid);
5140 	dquot = dqget(sb, qid);
5141 	if (IS_ERR(dquot))
5142 		return PTR_ERR(dquot);
5143 	spin_lock(&dq_data_lock);
5144 
5145 	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
5146 		 dquot->dq_dqb.dqb_bsoftlimit :
5147 		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
5148 	if (limit && buf->f_blocks > limit) {
5149 		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
5150 		buf->f_blocks = limit;
5151 		buf->f_bfree = buf->f_bavail =
5152 			(buf->f_blocks > curblock) ?
5153 			 (buf->f_blocks - curblock) : 0;
5154 	}
5155 
5156 	limit = dquot->dq_dqb.dqb_isoftlimit ?
5157 		dquot->dq_dqb.dqb_isoftlimit :
5158 		dquot->dq_dqb.dqb_ihardlimit;
5159 	if (limit && buf->f_files > limit) {
5160 		buf->f_files = limit;
5161 		buf->f_ffree =
5162 			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
5163 			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
5164 	}
5165 
5166 	spin_unlock(&dq_data_lock);
5167 	dqput(dquot);
5168 	return 0;
5169 }
5170 #endif
5171 
5172 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
5173 {
5174 	struct super_block *sb = dentry->d_sb;
5175 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5176 	struct ext4_super_block *es = sbi->s_es;
5177 	ext4_fsblk_t overhead = 0, resv_blocks;
5178 	u64 fsid;
5179 	s64 bfree;
5180 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
5181 
5182 	if (!test_opt(sb, MINIX_DF))
5183 		overhead = sbi->s_overhead;
5184 
5185 	buf->f_type = EXT4_SUPER_MAGIC;
5186 	buf->f_bsize = sb->s_blocksize;
5187 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
5188 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
5189 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
5190 	/* prevent underflow in case that few free space is available */
5191 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
5192 	buf->f_bavail = buf->f_bfree -
5193 			(ext4_r_blocks_count(es) + resv_blocks);
5194 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
5195 		buf->f_bavail = 0;
5196 	buf->f_files = le32_to_cpu(es->s_inodes_count);
5197 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
5198 	buf->f_namelen = EXT4_NAME_LEN;
5199 	fsid = le64_to_cpup((void *)es->s_uuid) ^
5200 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
5201 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
5202 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
5203 
5204 #ifdef CONFIG_QUOTA
5205 	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
5206 	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
5207 		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
5208 #endif
5209 	return 0;
5210 }
5211 
5212 /* Helper function for writing quotas on sync - we need to start transaction
5213  * before quota file is locked for write. Otherwise the are possible deadlocks:
5214  * Process 1                         Process 2
5215  * ext4_create()                     quota_sync()
5216  *   jbd2_journal_start()                  write_dquot()
5217  *   dquot_initialize()                         down(dqio_mutex)
5218  *     down(dqio_mutex)                    jbd2_journal_start()
5219  *
5220  */
5221 
5222 #ifdef CONFIG_QUOTA
5223 
5224 static inline struct inode *dquot_to_inode(struct dquot *dquot)
5225 {
5226 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
5227 }
5228 
5229 static int ext4_write_dquot(struct dquot *dquot)
5230 {
5231 	int ret, err;
5232 	handle_t *handle;
5233 	struct inode *inode;
5234 
5235 	inode = dquot_to_inode(dquot);
5236 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
5237 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
5238 	if (IS_ERR(handle))
5239 		return PTR_ERR(handle);
5240 	ret = dquot_commit(dquot);
5241 	err = ext4_journal_stop(handle);
5242 	if (!ret)
5243 		ret = err;
5244 	return ret;
5245 }
5246 
5247 static int ext4_acquire_dquot(struct dquot *dquot)
5248 {
5249 	int ret, err;
5250 	handle_t *handle;
5251 
5252 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5253 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
5254 	if (IS_ERR(handle))
5255 		return PTR_ERR(handle);
5256 	ret = dquot_acquire(dquot);
5257 	err = ext4_journal_stop(handle);
5258 	if (!ret)
5259 		ret = err;
5260 	return ret;
5261 }
5262 
5263 static int ext4_release_dquot(struct dquot *dquot)
5264 {
5265 	int ret, err;
5266 	handle_t *handle;
5267 
5268 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
5269 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
5270 	if (IS_ERR(handle)) {
5271 		/* Release dquot anyway to avoid endless cycle in dqput() */
5272 		dquot_release(dquot);
5273 		return PTR_ERR(handle);
5274 	}
5275 	ret = dquot_release(dquot);
5276 	err = ext4_journal_stop(handle);
5277 	if (!ret)
5278 		ret = err;
5279 	return ret;
5280 }
5281 
5282 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5283 {
5284 	struct super_block *sb = dquot->dq_sb;
5285 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5286 
5287 	/* Are we journaling quotas? */
5288 	if (ext4_has_feature_quota(sb) ||
5289 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5290 		dquot_mark_dquot_dirty(dquot);
5291 		return ext4_write_dquot(dquot);
5292 	} else {
5293 		return dquot_mark_dquot_dirty(dquot);
5294 	}
5295 }
5296 
5297 static int ext4_write_info(struct super_block *sb, int type)
5298 {
5299 	int ret, err;
5300 	handle_t *handle;
5301 
5302 	/* Data block + inode block */
5303 	handle = ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2);
5304 	if (IS_ERR(handle))
5305 		return PTR_ERR(handle);
5306 	ret = dquot_commit_info(sb, type);
5307 	err = ext4_journal_stop(handle);
5308 	if (!ret)
5309 		ret = err;
5310 	return ret;
5311 }
5312 
5313 /*
5314  * Turn on quotas during mount time - we need to find
5315  * the quota file and such...
5316  */
5317 static int ext4_quota_on_mount(struct super_block *sb, int type)
5318 {
5319 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5320 					EXT4_SB(sb)->s_jquota_fmt, type);
5321 }
5322 
5323 static void lockdep_set_quota_inode(struct inode *inode, int subclass)
5324 {
5325 	struct ext4_inode_info *ei = EXT4_I(inode);
5326 
5327 	/* The first argument of lockdep_set_subclass has to be
5328 	 * *exactly* the same as the argument to init_rwsem() --- in
5329 	 * this case, in init_once() --- or lockdep gets unhappy
5330 	 * because the name of the lock is set using the
5331 	 * stringification of the argument to init_rwsem().
5332 	 */
5333 	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
5334 	lockdep_set_subclass(&ei->i_data_sem, subclass);
5335 }
5336 
5337 /*
5338  * Standard function to be called on quota_on
5339  */
5340 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5341 			 const struct path *path)
5342 {
5343 	int err;
5344 
5345 	if (!test_opt(sb, QUOTA))
5346 		return -EINVAL;
5347 
5348 	/* Quotafile not on the same filesystem? */
5349 	if (path->dentry->d_sb != sb)
5350 		return -EXDEV;
5351 	/* Journaling quota? */
5352 	if (EXT4_SB(sb)->s_qf_names[type]) {
5353 		/* Quotafile not in fs root? */
5354 		if (path->dentry->d_parent != sb->s_root)
5355 			ext4_msg(sb, KERN_WARNING,
5356 				"Quota file not on filesystem root. "
5357 				"Journaled quota will not work");
5358 	}
5359 
5360 	/*
5361 	 * When we journal data on quota file, we have to flush journal to see
5362 	 * all updates to the file when we bypass pagecache...
5363 	 */
5364 	if (EXT4_SB(sb)->s_journal &&
5365 	    ext4_should_journal_data(d_inode(path->dentry))) {
5366 		/*
5367 		 * We don't need to lock updates but journal_flush() could
5368 		 * otherwise be livelocked...
5369 		 */
5370 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5371 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5372 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5373 		if (err)
5374 			return err;
5375 	}
5376 
5377 	lockdep_set_quota_inode(path->dentry->d_inode, I_DATA_SEM_QUOTA);
5378 	err = dquot_quota_on(sb, type, format_id, path);
5379 	if (err) {
5380 		lockdep_set_quota_inode(path->dentry->d_inode,
5381 					     I_DATA_SEM_NORMAL);
5382 	} else {
5383 		struct inode *inode = d_inode(path->dentry);
5384 		handle_t *handle;
5385 
5386 		/*
5387 		 * Set inode flags to prevent userspace from messing with quota
5388 		 * files. If this fails, we return success anyway since quotas
5389 		 * are already enabled and this is not a hard failure.
5390 		 */
5391 		inode_lock(inode);
5392 		handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5393 		if (IS_ERR(handle))
5394 			goto unlock_inode;
5395 		EXT4_I(inode)->i_flags |= EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL;
5396 		inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
5397 				S_NOATIME | S_IMMUTABLE);
5398 		ext4_mark_inode_dirty(handle, inode);
5399 		ext4_journal_stop(handle);
5400 	unlock_inode:
5401 		inode_unlock(inode);
5402 	}
5403 	return err;
5404 }
5405 
5406 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5407 			     unsigned int flags)
5408 {
5409 	int err;
5410 	struct inode *qf_inode;
5411 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5412 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5413 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5414 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5415 	};
5416 
5417 	BUG_ON(!ext4_has_feature_quota(sb));
5418 
5419 	if (!qf_inums[type])
5420 		return -EPERM;
5421 
5422 	qf_inode = ext4_iget(sb, qf_inums[type]);
5423 	if (IS_ERR(qf_inode)) {
5424 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5425 		return PTR_ERR(qf_inode);
5426 	}
5427 
5428 	/* Don't account quota for quota files to avoid recursion */
5429 	qf_inode->i_flags |= S_NOQUOTA;
5430 	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
5431 	err = dquot_enable(qf_inode, type, format_id, flags);
5432 	iput(qf_inode);
5433 	if (err)
5434 		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
5435 
5436 	return err;
5437 }
5438 
5439 /* Enable usage tracking for all quota types. */
5440 static int ext4_enable_quotas(struct super_block *sb)
5441 {
5442 	int type, err = 0;
5443 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
5444 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5445 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
5446 		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
5447 	};
5448 	bool quota_mopt[EXT4_MAXQUOTAS] = {
5449 		test_opt(sb, USRQUOTA),
5450 		test_opt(sb, GRPQUOTA),
5451 		test_opt(sb, PRJQUOTA),
5452 	};
5453 
5454 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5455 	for (type = 0; type < EXT4_MAXQUOTAS; type++) {
5456 		if (qf_inums[type]) {
5457 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5458 				DQUOT_USAGE_ENABLED |
5459 				(quota_mopt[type] ? DQUOT_LIMITS_ENABLED : 0));
5460 			if (err) {
5461 				ext4_warning(sb,
5462 					"Failed to enable quota tracking "
5463 					"(type=%d, err=%d). Please run "
5464 					"e2fsck to fix.", type, err);
5465 				return err;
5466 			}
5467 		}
5468 	}
5469 	return 0;
5470 }
5471 
5472 static int ext4_quota_off(struct super_block *sb, int type)
5473 {
5474 	struct inode *inode = sb_dqopt(sb)->files[type];
5475 	handle_t *handle;
5476 	int err;
5477 
5478 	/* Force all delayed allocation blocks to be allocated.
5479 	 * Caller already holds s_umount sem */
5480 	if (test_opt(sb, DELALLOC))
5481 		sync_filesystem(sb);
5482 
5483 	if (!inode || !igrab(inode))
5484 		goto out;
5485 
5486 	err = dquot_quota_off(sb, type);
5487 	if (err)
5488 		goto out_put;
5489 
5490 	inode_lock(inode);
5491 	/*
5492 	 * Update modification times of quota files when userspace can
5493 	 * start looking at them. If we fail, we return success anyway since
5494 	 * this is not a hard failure and quotas are already disabled.
5495 	 */
5496 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5497 	if (IS_ERR(handle))
5498 		goto out_unlock;
5499 	EXT4_I(inode)->i_flags &= ~(EXT4_NOATIME_FL | EXT4_IMMUTABLE_FL);
5500 	inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
5501 	inode->i_mtime = inode->i_ctime = current_time(inode);
5502 	ext4_mark_inode_dirty(handle, inode);
5503 	ext4_journal_stop(handle);
5504 out_unlock:
5505 	inode_unlock(inode);
5506 out_put:
5507 	iput(inode);
5508 	return err;
5509 out:
5510 	return dquot_quota_off(sb, type);
5511 }
5512 
5513 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5514  * acquiring the locks... As quota files are never truncated and quota code
5515  * itself serializes the operations (and no one else should touch the files)
5516  * we don't have to be afraid of races */
5517 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5518 			       size_t len, loff_t off)
5519 {
5520 	struct inode *inode = sb_dqopt(sb)->files[type];
5521 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5522 	int offset = off & (sb->s_blocksize - 1);
5523 	int tocopy;
5524 	size_t toread;
5525 	struct buffer_head *bh;
5526 	loff_t i_size = i_size_read(inode);
5527 
5528 	if (off > i_size)
5529 		return 0;
5530 	if (off+len > i_size)
5531 		len = i_size-off;
5532 	toread = len;
5533 	while (toread > 0) {
5534 		tocopy = sb->s_blocksize - offset < toread ?
5535 				sb->s_blocksize - offset : toread;
5536 		bh = ext4_bread(NULL, inode, blk, 0);
5537 		if (IS_ERR(bh))
5538 			return PTR_ERR(bh);
5539 		if (!bh)	/* A hole? */
5540 			memset(data, 0, tocopy);
5541 		else
5542 			memcpy(data, bh->b_data+offset, tocopy);
5543 		brelse(bh);
5544 		offset = 0;
5545 		toread -= tocopy;
5546 		data += tocopy;
5547 		blk++;
5548 	}
5549 	return len;
5550 }
5551 
5552 /* Write to quotafile (we know the transaction is already started and has
5553  * enough credits) */
5554 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5555 				const char *data, size_t len, loff_t off)
5556 {
5557 	struct inode *inode = sb_dqopt(sb)->files[type];
5558 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5559 	int err, offset = off & (sb->s_blocksize - 1);
5560 	int retries = 0;
5561 	struct buffer_head *bh;
5562 	handle_t *handle = journal_current_handle();
5563 
5564 	if (EXT4_SB(sb)->s_journal && !handle) {
5565 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5566 			" cancelled because transaction is not started",
5567 			(unsigned long long)off, (unsigned long long)len);
5568 		return -EIO;
5569 	}
5570 	/*
5571 	 * Since we account only one data block in transaction credits,
5572 	 * then it is impossible to cross a block boundary.
5573 	 */
5574 	if (sb->s_blocksize - offset < len) {
5575 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5576 			" cancelled because not block aligned",
5577 			(unsigned long long)off, (unsigned long long)len);
5578 		return -EIO;
5579 	}
5580 
5581 	do {
5582 		bh = ext4_bread(handle, inode, blk,
5583 				EXT4_GET_BLOCKS_CREATE |
5584 				EXT4_GET_BLOCKS_METADATA_NOFAIL);
5585 	} while (IS_ERR(bh) && (PTR_ERR(bh) == -ENOSPC) &&
5586 		 ext4_should_retry_alloc(inode->i_sb, &retries));
5587 	if (IS_ERR(bh))
5588 		return PTR_ERR(bh);
5589 	if (!bh)
5590 		goto out;
5591 	BUFFER_TRACE(bh, "get write access");
5592 	err = ext4_journal_get_write_access(handle, bh);
5593 	if (err) {
5594 		brelse(bh);
5595 		return err;
5596 	}
5597 	lock_buffer(bh);
5598 	memcpy(bh->b_data+offset, data, len);
5599 	flush_dcache_page(bh->b_page);
5600 	unlock_buffer(bh);
5601 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5602 	brelse(bh);
5603 out:
5604 	if (inode->i_size < off + len) {
5605 		i_size_write(inode, off + len);
5606 		EXT4_I(inode)->i_disksize = inode->i_size;
5607 		ext4_mark_inode_dirty(handle, inode);
5608 	}
5609 	return len;
5610 }
5611 
5612 static int ext4_get_next_id(struct super_block *sb, struct kqid *qid)
5613 {
5614 	const struct quota_format_ops	*ops;
5615 
5616 	if (!sb_has_quota_loaded(sb, qid->type))
5617 		return -ESRCH;
5618 	ops = sb_dqopt(sb)->ops[qid->type];
5619 	if (!ops || !ops->get_next_id)
5620 		return -ENOSYS;
5621 	return dquot_get_next_id(sb, qid);
5622 }
5623 #endif
5624 
5625 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5626 		       const char *dev_name, void *data)
5627 {
5628 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5629 }
5630 
5631 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
5632 static inline void register_as_ext2(void)
5633 {
5634 	int err = register_filesystem(&ext2_fs_type);
5635 	if (err)
5636 		printk(KERN_WARNING
5637 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5638 }
5639 
5640 static inline void unregister_as_ext2(void)
5641 {
5642 	unregister_filesystem(&ext2_fs_type);
5643 }
5644 
5645 static inline int ext2_feature_set_ok(struct super_block *sb)
5646 {
5647 	if (ext4_has_unknown_ext2_incompat_features(sb))
5648 		return 0;
5649 	if (sb->s_flags & MS_RDONLY)
5650 		return 1;
5651 	if (ext4_has_unknown_ext2_ro_compat_features(sb))
5652 		return 0;
5653 	return 1;
5654 }
5655 #else
5656 static inline void register_as_ext2(void) { }
5657 static inline void unregister_as_ext2(void) { }
5658 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5659 #endif
5660 
5661 static inline void register_as_ext3(void)
5662 {
5663 	int err = register_filesystem(&ext3_fs_type);
5664 	if (err)
5665 		printk(KERN_WARNING
5666 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5667 }
5668 
5669 static inline void unregister_as_ext3(void)
5670 {
5671 	unregister_filesystem(&ext3_fs_type);
5672 }
5673 
5674 static inline int ext3_feature_set_ok(struct super_block *sb)
5675 {
5676 	if (ext4_has_unknown_ext3_incompat_features(sb))
5677 		return 0;
5678 	if (!ext4_has_feature_journal(sb))
5679 		return 0;
5680 	if (sb->s_flags & MS_RDONLY)
5681 		return 1;
5682 	if (ext4_has_unknown_ext3_ro_compat_features(sb))
5683 		return 0;
5684 	return 1;
5685 }
5686 
5687 static struct file_system_type ext4_fs_type = {
5688 	.owner		= THIS_MODULE,
5689 	.name		= "ext4",
5690 	.mount		= ext4_mount,
5691 	.kill_sb	= kill_block_super,
5692 	.fs_flags	= FS_REQUIRES_DEV,
5693 };
5694 MODULE_ALIAS_FS("ext4");
5695 
5696 /* Shared across all ext4 file systems */
5697 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5698 
5699 static int __init ext4_init_fs(void)
5700 {
5701 	int i, err;
5702 
5703 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
5704 	ext4_li_info = NULL;
5705 	mutex_init(&ext4_li_mtx);
5706 
5707 	/* Build-time check for flags consistency */
5708 	ext4_check_flag_values();
5709 
5710 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++)
5711 		init_waitqueue_head(&ext4__ioend_wq[i]);
5712 
5713 	err = ext4_init_es();
5714 	if (err)
5715 		return err;
5716 
5717 	err = ext4_init_pageio();
5718 	if (err)
5719 		goto out5;
5720 
5721 	err = ext4_init_system_zone();
5722 	if (err)
5723 		goto out4;
5724 
5725 	err = ext4_init_sysfs();
5726 	if (err)
5727 		goto out3;
5728 
5729 	err = ext4_init_mballoc();
5730 	if (err)
5731 		goto out2;
5732 	err = init_inodecache();
5733 	if (err)
5734 		goto out1;
5735 	register_as_ext3();
5736 	register_as_ext2();
5737 	err = register_filesystem(&ext4_fs_type);
5738 	if (err)
5739 		goto out;
5740 
5741 	return 0;
5742 out:
5743 	unregister_as_ext2();
5744 	unregister_as_ext3();
5745 	destroy_inodecache();
5746 out1:
5747 	ext4_exit_mballoc();
5748 out2:
5749 	ext4_exit_sysfs();
5750 out3:
5751 	ext4_exit_system_zone();
5752 out4:
5753 	ext4_exit_pageio();
5754 out5:
5755 	ext4_exit_es();
5756 
5757 	return err;
5758 }
5759 
5760 static void __exit ext4_exit_fs(void)
5761 {
5762 	ext4_destroy_lazyinit_thread();
5763 	unregister_as_ext2();
5764 	unregister_as_ext3();
5765 	unregister_filesystem(&ext4_fs_type);
5766 	destroy_inodecache();
5767 	ext4_exit_mballoc();
5768 	ext4_exit_sysfs();
5769 	ext4_exit_system_zone();
5770 	ext4_exit_pageio();
5771 	ext4_exit_es();
5772 }
5773 
5774 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5775 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5776 MODULE_LICENSE("GPL");
5777 module_init(ext4_init_fs)
5778 module_exit(ext4_exit_fs)
5779