xref: /openbmc/linux/fs/ext4/super.c (revision 80ecbd24)
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/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.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/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62 
63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
64 			     unsigned long journal_devnum);
65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
66 static int ext4_commit_super(struct super_block *sb, int sync);
67 static void ext4_mark_recovery_complete(struct super_block *sb,
68 					struct ext4_super_block *es);
69 static void ext4_clear_journal_err(struct super_block *sb,
70 				   struct ext4_super_block *es);
71 static int ext4_sync_fs(struct super_block *sb, int wait);
72 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);
73 static int ext4_remount(struct super_block *sb, int *flags, char *data);
74 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
75 static int ext4_unfreeze(struct super_block *sb);
76 static int ext4_freeze(struct super_block *sb);
77 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
78 		       const char *dev_name, void *data);
79 static inline int ext2_feature_set_ok(struct super_block *sb);
80 static inline int ext3_feature_set_ok(struct super_block *sb);
81 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
82 static void ext4_destroy_lazyinit_thread(void);
83 static void ext4_unregister_li_request(struct super_block *sb);
84 static void ext4_clear_request_list(void);
85 static int ext4_reserve_clusters(struct ext4_sb_info *, ext4_fsblk_t);
86 
87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
88 static struct file_system_type ext2_fs_type = {
89 	.owner		= THIS_MODULE,
90 	.name		= "ext2",
91 	.mount		= ext4_mount,
92 	.kill_sb	= kill_block_super,
93 	.fs_flags	= FS_REQUIRES_DEV,
94 };
95 MODULE_ALIAS_FS("ext2");
96 MODULE_ALIAS("ext2");
97 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
98 #else
99 #define IS_EXT2_SB(sb) (0)
100 #endif
101 
102 
103 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
104 static struct file_system_type ext3_fs_type = {
105 	.owner		= THIS_MODULE,
106 	.name		= "ext3",
107 	.mount		= ext4_mount,
108 	.kill_sb	= kill_block_super,
109 	.fs_flags	= FS_REQUIRES_DEV,
110 };
111 MODULE_ALIAS_FS("ext3");
112 MODULE_ALIAS("ext3");
113 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
114 #else
115 #define IS_EXT3_SB(sb) (0)
116 #endif
117 
118 static int ext4_verify_csum_type(struct super_block *sb,
119 				 struct ext4_super_block *es)
120 {
121 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
122 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
123 		return 1;
124 
125 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
126 }
127 
128 static __le32 ext4_superblock_csum(struct super_block *sb,
129 				   struct ext4_super_block *es)
130 {
131 	struct ext4_sb_info *sbi = EXT4_SB(sb);
132 	int offset = offsetof(struct ext4_super_block, s_checksum);
133 	__u32 csum;
134 
135 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
136 
137 	return cpu_to_le32(csum);
138 }
139 
140 int ext4_superblock_csum_verify(struct super_block *sb,
141 				struct ext4_super_block *es)
142 {
143 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
144 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
145 		return 1;
146 
147 	return es->s_checksum == ext4_superblock_csum(sb, es);
148 }
149 
150 void ext4_superblock_csum_set(struct super_block *sb)
151 {
152 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
153 
154 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
155 		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
156 		return;
157 
158 	es->s_checksum = ext4_superblock_csum(sb, es);
159 }
160 
161 void *ext4_kvmalloc(size_t size, gfp_t flags)
162 {
163 	void *ret;
164 
165 	ret = kmalloc(size, flags);
166 	if (!ret)
167 		ret = __vmalloc(size, flags, PAGE_KERNEL);
168 	return ret;
169 }
170 
171 void *ext4_kvzalloc(size_t size, gfp_t flags)
172 {
173 	void *ret;
174 
175 	ret = kzalloc(size, flags);
176 	if (!ret)
177 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
178 	return ret;
179 }
180 
181 void ext4_kvfree(void *ptr)
182 {
183 	if (is_vmalloc_addr(ptr))
184 		vfree(ptr);
185 	else
186 		kfree(ptr);
187 
188 }
189 
190 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
191 			       struct ext4_group_desc *bg)
192 {
193 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
194 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
195 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
196 }
197 
198 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
199 			       struct ext4_group_desc *bg)
200 {
201 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
202 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
203 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
204 }
205 
206 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
207 			      struct ext4_group_desc *bg)
208 {
209 	return le32_to_cpu(bg->bg_inode_table_lo) |
210 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
211 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
212 }
213 
214 __u32 ext4_free_group_clusters(struct super_block *sb,
215 			       struct ext4_group_desc *bg)
216 {
217 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
218 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
219 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
220 }
221 
222 __u32 ext4_free_inodes_count(struct super_block *sb,
223 			      struct ext4_group_desc *bg)
224 {
225 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
226 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
227 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
228 }
229 
230 __u32 ext4_used_dirs_count(struct super_block *sb,
231 			      struct ext4_group_desc *bg)
232 {
233 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
234 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
235 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
236 }
237 
238 __u32 ext4_itable_unused_count(struct super_block *sb,
239 			      struct ext4_group_desc *bg)
240 {
241 	return le16_to_cpu(bg->bg_itable_unused_lo) |
242 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
243 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
244 }
245 
246 void ext4_block_bitmap_set(struct super_block *sb,
247 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
248 {
249 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
250 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
251 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
252 }
253 
254 void ext4_inode_bitmap_set(struct super_block *sb,
255 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
256 {
257 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
258 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
259 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
260 }
261 
262 void ext4_inode_table_set(struct super_block *sb,
263 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
264 {
265 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
266 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
267 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
268 }
269 
270 void ext4_free_group_clusters_set(struct super_block *sb,
271 				  struct ext4_group_desc *bg, __u32 count)
272 {
273 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
274 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
275 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
276 }
277 
278 void ext4_free_inodes_set(struct super_block *sb,
279 			  struct ext4_group_desc *bg, __u32 count)
280 {
281 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
282 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
283 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
284 }
285 
286 void ext4_used_dirs_set(struct super_block *sb,
287 			  struct ext4_group_desc *bg, __u32 count)
288 {
289 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
290 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
291 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
292 }
293 
294 void ext4_itable_unused_set(struct super_block *sb,
295 			  struct ext4_group_desc *bg, __u32 count)
296 {
297 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
298 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
299 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
300 }
301 
302 
303 static void __save_error_info(struct super_block *sb, const char *func,
304 			    unsigned int line)
305 {
306 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
307 
308 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
309 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
310 	es->s_last_error_time = cpu_to_le32(get_seconds());
311 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
312 	es->s_last_error_line = cpu_to_le32(line);
313 	if (!es->s_first_error_time) {
314 		es->s_first_error_time = es->s_last_error_time;
315 		strncpy(es->s_first_error_func, func,
316 			sizeof(es->s_first_error_func));
317 		es->s_first_error_line = cpu_to_le32(line);
318 		es->s_first_error_ino = es->s_last_error_ino;
319 		es->s_first_error_block = es->s_last_error_block;
320 	}
321 	/*
322 	 * Start the daily error reporting function if it hasn't been
323 	 * started already
324 	 */
325 	if (!es->s_error_count)
326 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
327 	le32_add_cpu(&es->s_error_count, 1);
328 }
329 
330 static void save_error_info(struct super_block *sb, const char *func,
331 			    unsigned int line)
332 {
333 	__save_error_info(sb, func, line);
334 	ext4_commit_super(sb, 1);
335 }
336 
337 /*
338  * The del_gendisk() function uninitializes the disk-specific data
339  * structures, including the bdi structure, without telling anyone
340  * else.  Once this happens, any attempt to call mark_buffer_dirty()
341  * (for example, by ext4_commit_super), will cause a kernel OOPS.
342  * This is a kludge to prevent these oops until we can put in a proper
343  * hook in del_gendisk() to inform the VFS and file system layers.
344  */
345 static int block_device_ejected(struct super_block *sb)
346 {
347 	struct inode *bd_inode = sb->s_bdev->bd_inode;
348 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
349 
350 	return bdi->dev == NULL;
351 }
352 
353 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
354 {
355 	struct super_block		*sb = journal->j_private;
356 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
357 	int				error = is_journal_aborted(journal);
358 	struct ext4_journal_cb_entry	*jce;
359 
360 	BUG_ON(txn->t_state == T_FINISHED);
361 	spin_lock(&sbi->s_md_lock);
362 	while (!list_empty(&txn->t_private_list)) {
363 		jce = list_entry(txn->t_private_list.next,
364 				 struct ext4_journal_cb_entry, jce_list);
365 		list_del_init(&jce->jce_list);
366 		spin_unlock(&sbi->s_md_lock);
367 		jce->jce_func(sb, jce, error);
368 		spin_lock(&sbi->s_md_lock);
369 	}
370 	spin_unlock(&sbi->s_md_lock);
371 }
372 
373 /* Deal with the reporting of failure conditions on a filesystem such as
374  * inconsistencies detected or read IO failures.
375  *
376  * On ext2, we can store the error state of the filesystem in the
377  * superblock.  That is not possible on ext4, because we may have other
378  * write ordering constraints on the superblock which prevent us from
379  * writing it out straight away; and given that the journal is about to
380  * be aborted, we can't rely on the current, or future, transactions to
381  * write out the superblock safely.
382  *
383  * We'll just use the jbd2_journal_abort() error code to record an error in
384  * the journal instead.  On recovery, the journal will complain about
385  * that error until we've noted it down and cleared it.
386  */
387 
388 static void ext4_handle_error(struct super_block *sb)
389 {
390 	if (sb->s_flags & MS_RDONLY)
391 		return;
392 
393 	if (!test_opt(sb, ERRORS_CONT)) {
394 		journal_t *journal = EXT4_SB(sb)->s_journal;
395 
396 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
397 		if (journal)
398 			jbd2_journal_abort(journal, -EIO);
399 	}
400 	if (test_opt(sb, ERRORS_RO)) {
401 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
402 		/*
403 		 * Make sure updated value of ->s_mount_flags will be visible
404 		 * before ->s_flags update
405 		 */
406 		smp_wmb();
407 		sb->s_flags |= MS_RDONLY;
408 	}
409 	if (test_opt(sb, ERRORS_PANIC))
410 		panic("EXT4-fs (device %s): panic forced after error\n",
411 			sb->s_id);
412 }
413 
414 void __ext4_error(struct super_block *sb, const char *function,
415 		  unsigned int line, const char *fmt, ...)
416 {
417 	struct va_format vaf;
418 	va_list args;
419 
420 	va_start(args, fmt);
421 	vaf.fmt = fmt;
422 	vaf.va = &args;
423 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
424 	       sb->s_id, function, line, current->comm, &vaf);
425 	va_end(args);
426 	save_error_info(sb, function, line);
427 
428 	ext4_handle_error(sb);
429 }
430 
431 void __ext4_error_inode(struct inode *inode, const char *function,
432 			unsigned int line, ext4_fsblk_t block,
433 			const char *fmt, ...)
434 {
435 	va_list args;
436 	struct va_format vaf;
437 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
438 
439 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
440 	es->s_last_error_block = cpu_to_le64(block);
441 	save_error_info(inode->i_sb, function, line);
442 	va_start(args, fmt);
443 	vaf.fmt = fmt;
444 	vaf.va = &args;
445 	if (block)
446 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
447 		       "inode #%lu: block %llu: comm %s: %pV\n",
448 		       inode->i_sb->s_id, function, line, inode->i_ino,
449 		       block, current->comm, &vaf);
450 	else
451 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
452 		       "inode #%lu: comm %s: %pV\n",
453 		       inode->i_sb->s_id, function, line, inode->i_ino,
454 		       current->comm, &vaf);
455 	va_end(args);
456 
457 	ext4_handle_error(inode->i_sb);
458 }
459 
460 void __ext4_error_file(struct file *file, const char *function,
461 		       unsigned int line, ext4_fsblk_t block,
462 		       const char *fmt, ...)
463 {
464 	va_list args;
465 	struct va_format vaf;
466 	struct ext4_super_block *es;
467 	struct inode *inode = file_inode(file);
468 	char pathname[80], *path;
469 
470 	es = EXT4_SB(inode->i_sb)->s_es;
471 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
472 	save_error_info(inode->i_sb, function, line);
473 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
474 	if (IS_ERR(path))
475 		path = "(unknown)";
476 	va_start(args, fmt);
477 	vaf.fmt = fmt;
478 	vaf.va = &args;
479 	if (block)
480 		printk(KERN_CRIT
481 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
482 		       "block %llu: comm %s: path %s: %pV\n",
483 		       inode->i_sb->s_id, function, line, inode->i_ino,
484 		       block, current->comm, path, &vaf);
485 	else
486 		printk(KERN_CRIT
487 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
488 		       "comm %s: path %s: %pV\n",
489 		       inode->i_sb->s_id, function, line, inode->i_ino,
490 		       current->comm, path, &vaf);
491 	va_end(args);
492 
493 	ext4_handle_error(inode->i_sb);
494 }
495 
496 const char *ext4_decode_error(struct super_block *sb, int errno,
497 			      char nbuf[16])
498 {
499 	char *errstr = NULL;
500 
501 	switch (errno) {
502 	case -EIO:
503 		errstr = "IO failure";
504 		break;
505 	case -ENOMEM:
506 		errstr = "Out of memory";
507 		break;
508 	case -EROFS:
509 		if (!sb || (EXT4_SB(sb)->s_journal &&
510 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
511 			errstr = "Journal has aborted";
512 		else
513 			errstr = "Readonly filesystem";
514 		break;
515 	default:
516 		/* If the caller passed in an extra buffer for unknown
517 		 * errors, textualise them now.  Else we just return
518 		 * NULL. */
519 		if (nbuf) {
520 			/* Check for truncated error codes... */
521 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
522 				errstr = nbuf;
523 		}
524 		break;
525 	}
526 
527 	return errstr;
528 }
529 
530 /* __ext4_std_error decodes expected errors from journaling functions
531  * automatically and invokes the appropriate error response.  */
532 
533 void __ext4_std_error(struct super_block *sb, const char *function,
534 		      unsigned int line, int errno)
535 {
536 	char nbuf[16];
537 	const char *errstr;
538 
539 	/* Special case: if the error is EROFS, and we're not already
540 	 * inside a transaction, then there's really no point in logging
541 	 * an error. */
542 	if (errno == -EROFS && journal_current_handle() == NULL &&
543 	    (sb->s_flags & MS_RDONLY))
544 		return;
545 
546 	errstr = ext4_decode_error(sb, errno, nbuf);
547 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
548 	       sb->s_id, function, line, errstr);
549 	save_error_info(sb, function, line);
550 
551 	ext4_handle_error(sb);
552 }
553 
554 /*
555  * ext4_abort is a much stronger failure handler than ext4_error.  The
556  * abort function may be used to deal with unrecoverable failures such
557  * as journal IO errors or ENOMEM at a critical moment in log management.
558  *
559  * We unconditionally force the filesystem into an ABORT|READONLY state,
560  * unless the error response on the fs has been set to panic in which
561  * case we take the easy way out and panic immediately.
562  */
563 
564 void __ext4_abort(struct super_block *sb, const char *function,
565 		unsigned int line, const char *fmt, ...)
566 {
567 	va_list args;
568 
569 	save_error_info(sb, function, line);
570 	va_start(args, fmt);
571 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
572 	       function, line);
573 	vprintk(fmt, args);
574 	printk("\n");
575 	va_end(args);
576 
577 	if ((sb->s_flags & MS_RDONLY) == 0) {
578 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
579 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
580 		/*
581 		 * Make sure updated value of ->s_mount_flags will be visible
582 		 * before ->s_flags update
583 		 */
584 		smp_wmb();
585 		sb->s_flags |= MS_RDONLY;
586 		if (EXT4_SB(sb)->s_journal)
587 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
588 		save_error_info(sb, function, line);
589 	}
590 	if (test_opt(sb, ERRORS_PANIC))
591 		panic("EXT4-fs panic from previous error\n");
592 }
593 
594 void __ext4_msg(struct super_block *sb,
595 		const char *prefix, const char *fmt, ...)
596 {
597 	struct va_format vaf;
598 	va_list args;
599 
600 	va_start(args, fmt);
601 	vaf.fmt = fmt;
602 	vaf.va = &args;
603 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
604 	va_end(args);
605 }
606 
607 void __ext4_warning(struct super_block *sb, const char *function,
608 		    unsigned int line, const char *fmt, ...)
609 {
610 	struct va_format vaf;
611 	va_list args;
612 
613 	va_start(args, fmt);
614 	vaf.fmt = fmt;
615 	vaf.va = &args;
616 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
617 	       sb->s_id, function, line, &vaf);
618 	va_end(args);
619 }
620 
621 void __ext4_grp_locked_error(const char *function, unsigned int line,
622 			     struct super_block *sb, ext4_group_t grp,
623 			     unsigned long ino, ext4_fsblk_t block,
624 			     const char *fmt, ...)
625 __releases(bitlock)
626 __acquires(bitlock)
627 {
628 	struct va_format vaf;
629 	va_list args;
630 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
631 
632 	es->s_last_error_ino = cpu_to_le32(ino);
633 	es->s_last_error_block = cpu_to_le64(block);
634 	__save_error_info(sb, function, line);
635 
636 	va_start(args, fmt);
637 
638 	vaf.fmt = fmt;
639 	vaf.va = &args;
640 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
641 	       sb->s_id, function, line, grp);
642 	if (ino)
643 		printk(KERN_CONT "inode %lu: ", ino);
644 	if (block)
645 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
646 	printk(KERN_CONT "%pV\n", &vaf);
647 	va_end(args);
648 
649 	if (test_opt(sb, ERRORS_CONT)) {
650 		ext4_commit_super(sb, 0);
651 		return;
652 	}
653 
654 	ext4_unlock_group(sb, grp);
655 	ext4_handle_error(sb);
656 	/*
657 	 * We only get here in the ERRORS_RO case; relocking the group
658 	 * may be dangerous, but nothing bad will happen since the
659 	 * filesystem will have already been marked read/only and the
660 	 * journal has been aborted.  We return 1 as a hint to callers
661 	 * who might what to use the return value from
662 	 * ext4_grp_locked_error() to distinguish between the
663 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
664 	 * aggressively from the ext4 function in question, with a
665 	 * more appropriate error code.
666 	 */
667 	ext4_lock_group(sb, grp);
668 	return;
669 }
670 
671 void ext4_update_dynamic_rev(struct super_block *sb)
672 {
673 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
674 
675 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
676 		return;
677 
678 	ext4_warning(sb,
679 		     "updating to rev %d because of new feature flag, "
680 		     "running e2fsck is recommended",
681 		     EXT4_DYNAMIC_REV);
682 
683 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
684 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
685 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
686 	/* leave es->s_feature_*compat flags alone */
687 	/* es->s_uuid will be set by e2fsck if empty */
688 
689 	/*
690 	 * The rest of the superblock fields should be zero, and if not it
691 	 * means they are likely already in use, so leave them alone.  We
692 	 * can leave it up to e2fsck to clean up any inconsistencies there.
693 	 */
694 }
695 
696 /*
697  * Open the external journal device
698  */
699 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
700 {
701 	struct block_device *bdev;
702 	char b[BDEVNAME_SIZE];
703 
704 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
705 	if (IS_ERR(bdev))
706 		goto fail;
707 	return bdev;
708 
709 fail:
710 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
711 			__bdevname(dev, b), PTR_ERR(bdev));
712 	return NULL;
713 }
714 
715 /*
716  * Release the journal device
717  */
718 static void ext4_blkdev_put(struct block_device *bdev)
719 {
720 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
721 }
722 
723 static void ext4_blkdev_remove(struct ext4_sb_info *sbi)
724 {
725 	struct block_device *bdev;
726 	bdev = sbi->journal_bdev;
727 	if (bdev) {
728 		ext4_blkdev_put(bdev);
729 		sbi->journal_bdev = NULL;
730 	}
731 }
732 
733 static inline struct inode *orphan_list_entry(struct list_head *l)
734 {
735 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
736 }
737 
738 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
739 {
740 	struct list_head *l;
741 
742 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
743 		 le32_to_cpu(sbi->s_es->s_last_orphan));
744 
745 	printk(KERN_ERR "sb_info orphan list:\n");
746 	list_for_each(l, &sbi->s_orphan) {
747 		struct inode *inode = orphan_list_entry(l);
748 		printk(KERN_ERR "  "
749 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
750 		       inode->i_sb->s_id, inode->i_ino, inode,
751 		       inode->i_mode, inode->i_nlink,
752 		       NEXT_ORPHAN(inode));
753 	}
754 }
755 
756 static void ext4_put_super(struct super_block *sb)
757 {
758 	struct ext4_sb_info *sbi = EXT4_SB(sb);
759 	struct ext4_super_block *es = sbi->s_es;
760 	int i, err;
761 
762 	ext4_unregister_li_request(sb);
763 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
764 
765 	flush_workqueue(sbi->unrsv_conversion_wq);
766 	flush_workqueue(sbi->rsv_conversion_wq);
767 	destroy_workqueue(sbi->unrsv_conversion_wq);
768 	destroy_workqueue(sbi->rsv_conversion_wq);
769 
770 	if (sbi->s_journal) {
771 		err = jbd2_journal_destroy(sbi->s_journal);
772 		sbi->s_journal = NULL;
773 		if (err < 0)
774 			ext4_abort(sb, "Couldn't clean up the journal");
775 	}
776 
777 	ext4_es_unregister_shrinker(sbi);
778 	del_timer(&sbi->s_err_report);
779 	ext4_release_system_zone(sb);
780 	ext4_mb_release(sb);
781 	ext4_ext_release(sb);
782 	ext4_xattr_put_super(sb);
783 
784 	if (!(sb->s_flags & MS_RDONLY)) {
785 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
786 		es->s_state = cpu_to_le16(sbi->s_mount_state);
787 	}
788 	if (!(sb->s_flags & MS_RDONLY))
789 		ext4_commit_super(sb, 1);
790 
791 	if (sbi->s_proc) {
792 		remove_proc_entry("options", sbi->s_proc);
793 		remove_proc_entry(sb->s_id, ext4_proc_root);
794 	}
795 	kobject_del(&sbi->s_kobj);
796 
797 	for (i = 0; i < sbi->s_gdb_count; i++)
798 		brelse(sbi->s_group_desc[i]);
799 	ext4_kvfree(sbi->s_group_desc);
800 	ext4_kvfree(sbi->s_flex_groups);
801 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
802 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
803 	percpu_counter_destroy(&sbi->s_dirs_counter);
804 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
805 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
806 	brelse(sbi->s_sbh);
807 #ifdef CONFIG_QUOTA
808 	for (i = 0; i < MAXQUOTAS; i++)
809 		kfree(sbi->s_qf_names[i]);
810 #endif
811 
812 	/* Debugging code just in case the in-memory inode orphan list
813 	 * isn't empty.  The on-disk one can be non-empty if we've
814 	 * detected an error and taken the fs readonly, but the
815 	 * in-memory list had better be clean by this point. */
816 	if (!list_empty(&sbi->s_orphan))
817 		dump_orphan_list(sb, sbi);
818 	J_ASSERT(list_empty(&sbi->s_orphan));
819 
820 	invalidate_bdev(sb->s_bdev);
821 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
822 		/*
823 		 * Invalidate the journal device's buffers.  We don't want them
824 		 * floating about in memory - the physical journal device may
825 		 * hotswapped, and it breaks the `ro-after' testing code.
826 		 */
827 		sync_blockdev(sbi->journal_bdev);
828 		invalidate_bdev(sbi->journal_bdev);
829 		ext4_blkdev_remove(sbi);
830 	}
831 	if (sbi->s_mmp_tsk)
832 		kthread_stop(sbi->s_mmp_tsk);
833 	sb->s_fs_info = NULL;
834 	/*
835 	 * Now that we are completely done shutting down the
836 	 * superblock, we need to actually destroy the kobject.
837 	 */
838 	kobject_put(&sbi->s_kobj);
839 	wait_for_completion(&sbi->s_kobj_unregister);
840 	if (sbi->s_chksum_driver)
841 		crypto_free_shash(sbi->s_chksum_driver);
842 	kfree(sbi->s_blockgroup_lock);
843 	kfree(sbi);
844 }
845 
846 static struct kmem_cache *ext4_inode_cachep;
847 
848 /*
849  * Called inside transaction, so use GFP_NOFS
850  */
851 static struct inode *ext4_alloc_inode(struct super_block *sb)
852 {
853 	struct ext4_inode_info *ei;
854 
855 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
856 	if (!ei)
857 		return NULL;
858 
859 	ei->vfs_inode.i_version = 1;
860 	INIT_LIST_HEAD(&ei->i_prealloc_list);
861 	spin_lock_init(&ei->i_prealloc_lock);
862 	ext4_es_init_tree(&ei->i_es_tree);
863 	rwlock_init(&ei->i_es_lock);
864 	INIT_LIST_HEAD(&ei->i_es_lru);
865 	ei->i_es_lru_nr = 0;
866 	ei->i_touch_when = 0;
867 	ei->i_reserved_data_blocks = 0;
868 	ei->i_reserved_meta_blocks = 0;
869 	ei->i_allocated_meta_blocks = 0;
870 	ei->i_da_metadata_calc_len = 0;
871 	ei->i_da_metadata_calc_last_lblock = 0;
872 	spin_lock_init(&(ei->i_block_reservation_lock));
873 #ifdef CONFIG_QUOTA
874 	ei->i_reserved_quota = 0;
875 #endif
876 	ei->jinode = NULL;
877 	INIT_LIST_HEAD(&ei->i_rsv_conversion_list);
878 	INIT_LIST_HEAD(&ei->i_unrsv_conversion_list);
879 	spin_lock_init(&ei->i_completed_io_lock);
880 	ei->i_sync_tid = 0;
881 	ei->i_datasync_tid = 0;
882 	atomic_set(&ei->i_ioend_count, 0);
883 	atomic_set(&ei->i_unwritten, 0);
884 	INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
885 	INIT_WORK(&ei->i_unrsv_conversion_work, ext4_end_io_unrsv_work);
886 
887 	return &ei->vfs_inode;
888 }
889 
890 static int ext4_drop_inode(struct inode *inode)
891 {
892 	int drop = generic_drop_inode(inode);
893 
894 	trace_ext4_drop_inode(inode, drop);
895 	return drop;
896 }
897 
898 static void ext4_i_callback(struct rcu_head *head)
899 {
900 	struct inode *inode = container_of(head, struct inode, i_rcu);
901 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
902 }
903 
904 static void ext4_destroy_inode(struct inode *inode)
905 {
906 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
907 		ext4_msg(inode->i_sb, KERN_ERR,
908 			 "Inode %lu (%p): orphan list check failed!",
909 			 inode->i_ino, EXT4_I(inode));
910 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
911 				EXT4_I(inode), sizeof(struct ext4_inode_info),
912 				true);
913 		dump_stack();
914 	}
915 	call_rcu(&inode->i_rcu, ext4_i_callback);
916 }
917 
918 static void init_once(void *foo)
919 {
920 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
921 
922 	INIT_LIST_HEAD(&ei->i_orphan);
923 	init_rwsem(&ei->xattr_sem);
924 	init_rwsem(&ei->i_data_sem);
925 	inode_init_once(&ei->vfs_inode);
926 }
927 
928 static int init_inodecache(void)
929 {
930 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
931 					     sizeof(struct ext4_inode_info),
932 					     0, (SLAB_RECLAIM_ACCOUNT|
933 						SLAB_MEM_SPREAD),
934 					     init_once);
935 	if (ext4_inode_cachep == NULL)
936 		return -ENOMEM;
937 	return 0;
938 }
939 
940 static void destroy_inodecache(void)
941 {
942 	/*
943 	 * Make sure all delayed rcu free inodes are flushed before we
944 	 * destroy cache.
945 	 */
946 	rcu_barrier();
947 	kmem_cache_destroy(ext4_inode_cachep);
948 }
949 
950 void ext4_clear_inode(struct inode *inode)
951 {
952 	invalidate_inode_buffers(inode);
953 	clear_inode(inode);
954 	dquot_drop(inode);
955 	ext4_discard_preallocations(inode);
956 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
957 	ext4_es_lru_del(inode);
958 	if (EXT4_I(inode)->jinode) {
959 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
960 					       EXT4_I(inode)->jinode);
961 		jbd2_free_inode(EXT4_I(inode)->jinode);
962 		EXT4_I(inode)->jinode = NULL;
963 	}
964 }
965 
966 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
967 					u64 ino, u32 generation)
968 {
969 	struct inode *inode;
970 
971 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
972 		return ERR_PTR(-ESTALE);
973 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
974 		return ERR_PTR(-ESTALE);
975 
976 	/* iget isn't really right if the inode is currently unallocated!!
977 	 *
978 	 * ext4_read_inode will return a bad_inode if the inode had been
979 	 * deleted, so we should be safe.
980 	 *
981 	 * Currently we don't know the generation for parent directory, so
982 	 * a generation of 0 means "accept any"
983 	 */
984 	inode = ext4_iget(sb, ino);
985 	if (IS_ERR(inode))
986 		return ERR_CAST(inode);
987 	if (generation && inode->i_generation != generation) {
988 		iput(inode);
989 		return ERR_PTR(-ESTALE);
990 	}
991 
992 	return inode;
993 }
994 
995 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
996 					int fh_len, int fh_type)
997 {
998 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
999 				    ext4_nfs_get_inode);
1000 }
1001 
1002 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1003 					int fh_len, int fh_type)
1004 {
1005 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1006 				    ext4_nfs_get_inode);
1007 }
1008 
1009 /*
1010  * Try to release metadata pages (indirect blocks, directories) which are
1011  * mapped via the block device.  Since these pages could have journal heads
1012  * which would prevent try_to_free_buffers() from freeing them, we must use
1013  * jbd2 layer's try_to_free_buffers() function to release them.
1014  */
1015 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1016 				 gfp_t wait)
1017 {
1018 	journal_t *journal = EXT4_SB(sb)->s_journal;
1019 
1020 	WARN_ON(PageChecked(page));
1021 	if (!page_has_buffers(page))
1022 		return 0;
1023 	if (journal)
1024 		return jbd2_journal_try_to_free_buffers(journal, page,
1025 							wait & ~__GFP_WAIT);
1026 	return try_to_free_buffers(page);
1027 }
1028 
1029 #ifdef CONFIG_QUOTA
1030 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1031 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1032 
1033 static int ext4_write_dquot(struct dquot *dquot);
1034 static int ext4_acquire_dquot(struct dquot *dquot);
1035 static int ext4_release_dquot(struct dquot *dquot);
1036 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1037 static int ext4_write_info(struct super_block *sb, int type);
1038 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1039 			 struct path *path);
1040 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1041 				 int format_id);
1042 static int ext4_quota_off(struct super_block *sb, int type);
1043 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1044 static int ext4_quota_on_mount(struct super_block *sb, int type);
1045 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1046 			       size_t len, loff_t off);
1047 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1048 				const char *data, size_t len, loff_t off);
1049 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1050 			     unsigned int flags);
1051 static int ext4_enable_quotas(struct super_block *sb);
1052 
1053 static const struct dquot_operations ext4_quota_operations = {
1054 	.get_reserved_space = ext4_get_reserved_space,
1055 	.write_dquot	= ext4_write_dquot,
1056 	.acquire_dquot	= ext4_acquire_dquot,
1057 	.release_dquot	= ext4_release_dquot,
1058 	.mark_dirty	= ext4_mark_dquot_dirty,
1059 	.write_info	= ext4_write_info,
1060 	.alloc_dquot	= dquot_alloc,
1061 	.destroy_dquot	= dquot_destroy,
1062 };
1063 
1064 static const struct quotactl_ops ext4_qctl_operations = {
1065 	.quota_on	= ext4_quota_on,
1066 	.quota_off	= ext4_quota_off,
1067 	.quota_sync	= dquot_quota_sync,
1068 	.get_info	= dquot_get_dqinfo,
1069 	.set_info	= dquot_set_dqinfo,
1070 	.get_dqblk	= dquot_get_dqblk,
1071 	.set_dqblk	= dquot_set_dqblk
1072 };
1073 
1074 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1075 	.quota_on_meta	= ext4_quota_on_sysfile,
1076 	.quota_off	= ext4_quota_off_sysfile,
1077 	.quota_sync	= dquot_quota_sync,
1078 	.get_info	= dquot_get_dqinfo,
1079 	.set_info	= dquot_set_dqinfo,
1080 	.get_dqblk	= dquot_get_dqblk,
1081 	.set_dqblk	= dquot_set_dqblk
1082 };
1083 #endif
1084 
1085 static const struct super_operations ext4_sops = {
1086 	.alloc_inode	= ext4_alloc_inode,
1087 	.destroy_inode	= ext4_destroy_inode,
1088 	.write_inode	= ext4_write_inode,
1089 	.dirty_inode	= ext4_dirty_inode,
1090 	.drop_inode	= ext4_drop_inode,
1091 	.evict_inode	= ext4_evict_inode,
1092 	.put_super	= ext4_put_super,
1093 	.sync_fs	= ext4_sync_fs,
1094 	.freeze_fs	= ext4_freeze,
1095 	.unfreeze_fs	= ext4_unfreeze,
1096 	.statfs		= ext4_statfs,
1097 	.remount_fs	= ext4_remount,
1098 	.show_options	= ext4_show_options,
1099 #ifdef CONFIG_QUOTA
1100 	.quota_read	= ext4_quota_read,
1101 	.quota_write	= ext4_quota_write,
1102 #endif
1103 	.bdev_try_to_free_page = bdev_try_to_free_page,
1104 };
1105 
1106 static const struct super_operations ext4_nojournal_sops = {
1107 	.alloc_inode	= ext4_alloc_inode,
1108 	.destroy_inode	= ext4_destroy_inode,
1109 	.write_inode	= ext4_write_inode,
1110 	.dirty_inode	= ext4_dirty_inode,
1111 	.drop_inode	= ext4_drop_inode,
1112 	.evict_inode	= ext4_evict_inode,
1113 	.sync_fs	= ext4_sync_fs_nojournal,
1114 	.put_super	= ext4_put_super,
1115 	.statfs		= ext4_statfs,
1116 	.remount_fs	= ext4_remount,
1117 	.show_options	= ext4_show_options,
1118 #ifdef CONFIG_QUOTA
1119 	.quota_read	= ext4_quota_read,
1120 	.quota_write	= ext4_quota_write,
1121 #endif
1122 	.bdev_try_to_free_page = bdev_try_to_free_page,
1123 };
1124 
1125 static const struct export_operations ext4_export_ops = {
1126 	.fh_to_dentry = ext4_fh_to_dentry,
1127 	.fh_to_parent = ext4_fh_to_parent,
1128 	.get_parent = ext4_get_parent,
1129 };
1130 
1131 enum {
1132 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1133 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1134 	Opt_nouid32, Opt_debug, Opt_removed,
1135 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1136 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1137 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1138 	Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1139 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1140 	Opt_data_err_abort, Opt_data_err_ignore,
1141 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1142 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1143 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1144 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1145 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1146 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1147 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1148 	Opt_dioread_nolock, Opt_dioread_lock,
1149 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1150 	Opt_max_dir_size_kb,
1151 };
1152 
1153 static const match_table_t tokens = {
1154 	{Opt_bsd_df, "bsddf"},
1155 	{Opt_minix_df, "minixdf"},
1156 	{Opt_grpid, "grpid"},
1157 	{Opt_grpid, "bsdgroups"},
1158 	{Opt_nogrpid, "nogrpid"},
1159 	{Opt_nogrpid, "sysvgroups"},
1160 	{Opt_resgid, "resgid=%u"},
1161 	{Opt_resuid, "resuid=%u"},
1162 	{Opt_sb, "sb=%u"},
1163 	{Opt_err_cont, "errors=continue"},
1164 	{Opt_err_panic, "errors=panic"},
1165 	{Opt_err_ro, "errors=remount-ro"},
1166 	{Opt_nouid32, "nouid32"},
1167 	{Opt_debug, "debug"},
1168 	{Opt_removed, "oldalloc"},
1169 	{Opt_removed, "orlov"},
1170 	{Opt_user_xattr, "user_xattr"},
1171 	{Opt_nouser_xattr, "nouser_xattr"},
1172 	{Opt_acl, "acl"},
1173 	{Opt_noacl, "noacl"},
1174 	{Opt_noload, "norecovery"},
1175 	{Opt_noload, "noload"},
1176 	{Opt_removed, "nobh"},
1177 	{Opt_removed, "bh"},
1178 	{Opt_commit, "commit=%u"},
1179 	{Opt_min_batch_time, "min_batch_time=%u"},
1180 	{Opt_max_batch_time, "max_batch_time=%u"},
1181 	{Opt_journal_dev, "journal_dev=%u"},
1182 	{Opt_journal_checksum, "journal_checksum"},
1183 	{Opt_journal_async_commit, "journal_async_commit"},
1184 	{Opt_abort, "abort"},
1185 	{Opt_data_journal, "data=journal"},
1186 	{Opt_data_ordered, "data=ordered"},
1187 	{Opt_data_writeback, "data=writeback"},
1188 	{Opt_data_err_abort, "data_err=abort"},
1189 	{Opt_data_err_ignore, "data_err=ignore"},
1190 	{Opt_offusrjquota, "usrjquota="},
1191 	{Opt_usrjquota, "usrjquota=%s"},
1192 	{Opt_offgrpjquota, "grpjquota="},
1193 	{Opt_grpjquota, "grpjquota=%s"},
1194 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1195 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1196 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1197 	{Opt_grpquota, "grpquota"},
1198 	{Opt_noquota, "noquota"},
1199 	{Opt_quota, "quota"},
1200 	{Opt_usrquota, "usrquota"},
1201 	{Opt_barrier, "barrier=%u"},
1202 	{Opt_barrier, "barrier"},
1203 	{Opt_nobarrier, "nobarrier"},
1204 	{Opt_i_version, "i_version"},
1205 	{Opt_stripe, "stripe=%u"},
1206 	{Opt_delalloc, "delalloc"},
1207 	{Opt_nodelalloc, "nodelalloc"},
1208 	{Opt_removed, "mblk_io_submit"},
1209 	{Opt_removed, "nomblk_io_submit"},
1210 	{Opt_block_validity, "block_validity"},
1211 	{Opt_noblock_validity, "noblock_validity"},
1212 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1213 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1214 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1215 	{Opt_auto_da_alloc, "auto_da_alloc"},
1216 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1217 	{Opt_dioread_nolock, "dioread_nolock"},
1218 	{Opt_dioread_lock, "dioread_lock"},
1219 	{Opt_discard, "discard"},
1220 	{Opt_nodiscard, "nodiscard"},
1221 	{Opt_init_itable, "init_itable=%u"},
1222 	{Opt_init_itable, "init_itable"},
1223 	{Opt_noinit_itable, "noinit_itable"},
1224 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1225 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1226 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1227 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1228 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1229 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1230 	{Opt_err, NULL},
1231 };
1232 
1233 static ext4_fsblk_t get_sb_block(void **data)
1234 {
1235 	ext4_fsblk_t	sb_block;
1236 	char		*options = (char *) *data;
1237 
1238 	if (!options || strncmp(options, "sb=", 3) != 0)
1239 		return 1;	/* Default location */
1240 
1241 	options += 3;
1242 	/* TODO: use simple_strtoll with >32bit ext4 */
1243 	sb_block = simple_strtoul(options, &options, 0);
1244 	if (*options && *options != ',') {
1245 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1246 		       (char *) *data);
1247 		return 1;
1248 	}
1249 	if (*options == ',')
1250 		options++;
1251 	*data = (void *) options;
1252 
1253 	return sb_block;
1254 }
1255 
1256 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1257 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1258 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1259 
1260 #ifdef CONFIG_QUOTA
1261 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1262 {
1263 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1264 	char *qname;
1265 	int ret = -1;
1266 
1267 	if (sb_any_quota_loaded(sb) &&
1268 		!sbi->s_qf_names[qtype]) {
1269 		ext4_msg(sb, KERN_ERR,
1270 			"Cannot change journaled "
1271 			"quota options when quota turned on");
1272 		return -1;
1273 	}
1274 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1275 		ext4_msg(sb, KERN_ERR, "Cannot set journaled quota options "
1276 			 "when QUOTA feature is enabled");
1277 		return -1;
1278 	}
1279 	qname = match_strdup(args);
1280 	if (!qname) {
1281 		ext4_msg(sb, KERN_ERR,
1282 			"Not enough memory for storing quotafile name");
1283 		return -1;
1284 	}
1285 	if (sbi->s_qf_names[qtype]) {
1286 		if (strcmp(sbi->s_qf_names[qtype], qname) == 0)
1287 			ret = 1;
1288 		else
1289 			ext4_msg(sb, KERN_ERR,
1290 				 "%s quota file already specified",
1291 				 QTYPE2NAME(qtype));
1292 		goto errout;
1293 	}
1294 	if (strchr(qname, '/')) {
1295 		ext4_msg(sb, KERN_ERR,
1296 			"quotafile must be on filesystem root");
1297 		goto errout;
1298 	}
1299 	sbi->s_qf_names[qtype] = qname;
1300 	set_opt(sb, QUOTA);
1301 	return 1;
1302 errout:
1303 	kfree(qname);
1304 	return ret;
1305 }
1306 
1307 static int clear_qf_name(struct super_block *sb, int qtype)
1308 {
1309 
1310 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1311 
1312 	if (sb_any_quota_loaded(sb) &&
1313 		sbi->s_qf_names[qtype]) {
1314 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1315 			" when quota turned on");
1316 		return -1;
1317 	}
1318 	kfree(sbi->s_qf_names[qtype]);
1319 	sbi->s_qf_names[qtype] = NULL;
1320 	return 1;
1321 }
1322 #endif
1323 
1324 #define MOPT_SET	0x0001
1325 #define MOPT_CLEAR	0x0002
1326 #define MOPT_NOSUPPORT	0x0004
1327 #define MOPT_EXPLICIT	0x0008
1328 #define MOPT_CLEAR_ERR	0x0010
1329 #define MOPT_GTE0	0x0020
1330 #ifdef CONFIG_QUOTA
1331 #define MOPT_Q		0
1332 #define MOPT_QFMT	0x0040
1333 #else
1334 #define MOPT_Q		MOPT_NOSUPPORT
1335 #define MOPT_QFMT	MOPT_NOSUPPORT
1336 #endif
1337 #define MOPT_DATAJ	0x0080
1338 #define MOPT_NO_EXT2	0x0100
1339 #define MOPT_NO_EXT3	0x0200
1340 #define MOPT_EXT4_ONLY	(MOPT_NO_EXT2 | MOPT_NO_EXT3)
1341 
1342 static const struct mount_opts {
1343 	int	token;
1344 	int	mount_opt;
1345 	int	flags;
1346 } ext4_mount_opts[] = {
1347 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1348 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1349 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1350 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1351 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1352 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1353 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK,
1354 	 MOPT_EXT4_ONLY | MOPT_SET},
1355 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK,
1356 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1357 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1358 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1359 	{Opt_delalloc, EXT4_MOUNT_DELALLOC,
1360 	 MOPT_EXT4_ONLY | MOPT_SET | MOPT_EXPLICIT},
1361 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC,
1362 	 MOPT_EXT4_ONLY | MOPT_CLEAR},
1363 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM,
1364 	 MOPT_EXT4_ONLY | MOPT_SET},
1365 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1366 				    EXT4_MOUNT_JOURNAL_CHECKSUM),
1367 	 MOPT_EXT4_ONLY | MOPT_SET},
1368 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_NO_EXT2 | MOPT_SET},
1369 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1370 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1371 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1372 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT,
1373 	 MOPT_NO_EXT2 | MOPT_SET},
1374 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT,
1375 	 MOPT_NO_EXT2 | MOPT_CLEAR},
1376 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1377 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1378 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1379 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1380 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1381 	{Opt_commit, 0, MOPT_GTE0},
1382 	{Opt_max_batch_time, 0, MOPT_GTE0},
1383 	{Opt_min_batch_time, 0, MOPT_GTE0},
1384 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1385 	{Opt_init_itable, 0, MOPT_GTE0},
1386 	{Opt_stripe, 0, MOPT_GTE0},
1387 	{Opt_resuid, 0, MOPT_GTE0},
1388 	{Opt_resgid, 0, MOPT_GTE0},
1389 	{Opt_journal_dev, 0, MOPT_GTE0},
1390 	{Opt_journal_ioprio, 0, MOPT_GTE0},
1391 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1392 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_NO_EXT2 | MOPT_DATAJ},
1393 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA,
1394 	 MOPT_NO_EXT2 | MOPT_DATAJ},
1395 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1396 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1397 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1398 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1399 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1400 #else
1401 	{Opt_acl, 0, MOPT_NOSUPPORT},
1402 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1403 #endif
1404 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1405 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1406 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1407 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1408 							MOPT_SET | MOPT_Q},
1409 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1410 							MOPT_SET | MOPT_Q},
1411 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1412 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1413 	{Opt_usrjquota, 0, MOPT_Q},
1414 	{Opt_grpjquota, 0, MOPT_Q},
1415 	{Opt_offusrjquota, 0, MOPT_Q},
1416 	{Opt_offgrpjquota, 0, MOPT_Q},
1417 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1418 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1419 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1420 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1421 	{Opt_err, 0, 0}
1422 };
1423 
1424 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1425 			    substring_t *args, unsigned long *journal_devnum,
1426 			    unsigned int *journal_ioprio, int is_remount)
1427 {
1428 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1429 	const struct mount_opts *m;
1430 	kuid_t uid;
1431 	kgid_t gid;
1432 	int arg = 0;
1433 
1434 #ifdef CONFIG_QUOTA
1435 	if (token == Opt_usrjquota)
1436 		return set_qf_name(sb, USRQUOTA, &args[0]);
1437 	else if (token == Opt_grpjquota)
1438 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1439 	else if (token == Opt_offusrjquota)
1440 		return clear_qf_name(sb, USRQUOTA);
1441 	else if (token == Opt_offgrpjquota)
1442 		return clear_qf_name(sb, GRPQUOTA);
1443 #endif
1444 	switch (token) {
1445 	case Opt_noacl:
1446 	case Opt_nouser_xattr:
1447 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1448 		break;
1449 	case Opt_sb:
1450 		return 1;	/* handled by get_sb_block() */
1451 	case Opt_removed:
1452 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
1453 		return 1;
1454 	case Opt_abort:
1455 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1456 		return 1;
1457 	case Opt_i_version:
1458 		sb->s_flags |= MS_I_VERSION;
1459 		return 1;
1460 	}
1461 
1462 	for (m = ext4_mount_opts; m->token != Opt_err; m++)
1463 		if (token == m->token)
1464 			break;
1465 
1466 	if (m->token == Opt_err) {
1467 		ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1468 			 "or missing value", opt);
1469 		return -1;
1470 	}
1471 
1472 	if ((m->flags & MOPT_NO_EXT2) && IS_EXT2_SB(sb)) {
1473 		ext4_msg(sb, KERN_ERR,
1474 			 "Mount option \"%s\" incompatible with ext2", opt);
1475 		return -1;
1476 	}
1477 	if ((m->flags & MOPT_NO_EXT3) && IS_EXT3_SB(sb)) {
1478 		ext4_msg(sb, KERN_ERR,
1479 			 "Mount option \"%s\" incompatible with ext3", opt);
1480 		return -1;
1481 	}
1482 
1483 	if (args->from && match_int(args, &arg))
1484 		return -1;
1485 	if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1486 		return -1;
1487 	if (m->flags & MOPT_EXPLICIT)
1488 		set_opt2(sb, EXPLICIT_DELALLOC);
1489 	if (m->flags & MOPT_CLEAR_ERR)
1490 		clear_opt(sb, ERRORS_MASK);
1491 	if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1492 		ext4_msg(sb, KERN_ERR, "Cannot change quota "
1493 			 "options when quota turned on");
1494 		return -1;
1495 	}
1496 
1497 	if (m->flags & MOPT_NOSUPPORT) {
1498 		ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1499 	} else if (token == Opt_commit) {
1500 		if (arg == 0)
1501 			arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1502 		sbi->s_commit_interval = HZ * arg;
1503 	} else if (token == Opt_max_batch_time) {
1504 		if (arg == 0)
1505 			arg = EXT4_DEF_MAX_BATCH_TIME;
1506 		sbi->s_max_batch_time = arg;
1507 	} else if (token == Opt_min_batch_time) {
1508 		sbi->s_min_batch_time = arg;
1509 	} else if (token == Opt_inode_readahead_blks) {
1510 		if (arg && (arg > (1 << 30) || !is_power_of_2(arg))) {
1511 			ext4_msg(sb, KERN_ERR,
1512 				 "EXT4-fs: inode_readahead_blks must be "
1513 				 "0 or a power of 2 smaller than 2^31");
1514 			return -1;
1515 		}
1516 		sbi->s_inode_readahead_blks = arg;
1517 	} else if (token == Opt_init_itable) {
1518 		set_opt(sb, INIT_INODE_TABLE);
1519 		if (!args->from)
1520 			arg = EXT4_DEF_LI_WAIT_MULT;
1521 		sbi->s_li_wait_mult = arg;
1522 	} else if (token == Opt_max_dir_size_kb) {
1523 		sbi->s_max_dir_size_kb = arg;
1524 	} else if (token == Opt_stripe) {
1525 		sbi->s_stripe = arg;
1526 	} else if (token == Opt_resuid) {
1527 		uid = make_kuid(current_user_ns(), arg);
1528 		if (!uid_valid(uid)) {
1529 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1530 			return -1;
1531 		}
1532 		sbi->s_resuid = uid;
1533 	} else if (token == Opt_resgid) {
1534 		gid = make_kgid(current_user_ns(), arg);
1535 		if (!gid_valid(gid)) {
1536 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1537 			return -1;
1538 		}
1539 		sbi->s_resgid = gid;
1540 	} else if (token == Opt_journal_dev) {
1541 		if (is_remount) {
1542 			ext4_msg(sb, KERN_ERR,
1543 				 "Cannot specify journal on remount");
1544 			return -1;
1545 		}
1546 		*journal_devnum = arg;
1547 	} else if (token == Opt_journal_ioprio) {
1548 		if (arg > 7) {
1549 			ext4_msg(sb, KERN_ERR, "Invalid journal IO priority"
1550 				 " (must be 0-7)");
1551 			return -1;
1552 		}
1553 		*journal_ioprio =
1554 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1555 	} else if (m->flags & MOPT_DATAJ) {
1556 		if (is_remount) {
1557 			if (!sbi->s_journal)
1558 				ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1559 			else if (test_opt(sb, DATA_FLAGS) != m->mount_opt) {
1560 				ext4_msg(sb, KERN_ERR,
1561 					 "Cannot change data mode on remount");
1562 				return -1;
1563 			}
1564 		} else {
1565 			clear_opt(sb, DATA_FLAGS);
1566 			sbi->s_mount_opt |= m->mount_opt;
1567 		}
1568 #ifdef CONFIG_QUOTA
1569 	} else if (m->flags & MOPT_QFMT) {
1570 		if (sb_any_quota_loaded(sb) &&
1571 		    sbi->s_jquota_fmt != m->mount_opt) {
1572 			ext4_msg(sb, KERN_ERR, "Cannot change journaled "
1573 				 "quota options when quota turned on");
1574 			return -1;
1575 		}
1576 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
1577 					       EXT4_FEATURE_RO_COMPAT_QUOTA)) {
1578 			ext4_msg(sb, KERN_ERR,
1579 				 "Cannot set journaled quota options "
1580 				 "when QUOTA feature is enabled");
1581 			return -1;
1582 		}
1583 		sbi->s_jquota_fmt = m->mount_opt;
1584 #endif
1585 	} else {
1586 		if (!args->from)
1587 			arg = 1;
1588 		if (m->flags & MOPT_CLEAR)
1589 			arg = !arg;
1590 		else if (unlikely(!(m->flags & MOPT_SET))) {
1591 			ext4_msg(sb, KERN_WARNING,
1592 				 "buggy handling of option %s", opt);
1593 			WARN_ON(1);
1594 			return -1;
1595 		}
1596 		if (arg != 0)
1597 			sbi->s_mount_opt |= m->mount_opt;
1598 		else
1599 			sbi->s_mount_opt &= ~m->mount_opt;
1600 	}
1601 	return 1;
1602 }
1603 
1604 static int parse_options(char *options, struct super_block *sb,
1605 			 unsigned long *journal_devnum,
1606 			 unsigned int *journal_ioprio,
1607 			 int is_remount)
1608 {
1609 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1610 	char *p;
1611 	substring_t args[MAX_OPT_ARGS];
1612 	int token;
1613 
1614 	if (!options)
1615 		return 1;
1616 
1617 	while ((p = strsep(&options, ",")) != NULL) {
1618 		if (!*p)
1619 			continue;
1620 		/*
1621 		 * Initialize args struct so we know whether arg was
1622 		 * found; some options take optional arguments.
1623 		 */
1624 		args[0].to = args[0].from = NULL;
1625 		token = match_token(p, tokens, args);
1626 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1627 				     journal_ioprio, is_remount) < 0)
1628 			return 0;
1629 	}
1630 #ifdef CONFIG_QUOTA
1631 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
1632 	    (test_opt(sb, USRQUOTA) || test_opt(sb, GRPQUOTA))) {
1633 		ext4_msg(sb, KERN_ERR, "Cannot set quota options when QUOTA "
1634 			 "feature is enabled");
1635 		return 0;
1636 	}
1637 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1638 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1639 			clear_opt(sb, USRQUOTA);
1640 
1641 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1642 			clear_opt(sb, GRPQUOTA);
1643 
1644 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1645 			ext4_msg(sb, KERN_ERR, "old and new quota "
1646 					"format mixing");
1647 			return 0;
1648 		}
1649 
1650 		if (!sbi->s_jquota_fmt) {
1651 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1652 					"not specified");
1653 			return 0;
1654 		}
1655 	} else {
1656 		if (sbi->s_jquota_fmt) {
1657 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1658 					"specified with no journaling "
1659 					"enabled");
1660 			return 0;
1661 		}
1662 	}
1663 #endif
1664 	if (test_opt(sb, DIOREAD_NOLOCK)) {
1665 		int blocksize =
1666 			BLOCK_SIZE << le32_to_cpu(sbi->s_es->s_log_block_size);
1667 
1668 		if (blocksize < PAGE_CACHE_SIZE) {
1669 			ext4_msg(sb, KERN_ERR, "can't mount with "
1670 				 "dioread_nolock if block size != PAGE_SIZE");
1671 			return 0;
1672 		}
1673 	}
1674 	return 1;
1675 }
1676 
1677 static inline void ext4_show_quota_options(struct seq_file *seq,
1678 					   struct super_block *sb)
1679 {
1680 #if defined(CONFIG_QUOTA)
1681 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1682 
1683 	if (sbi->s_jquota_fmt) {
1684 		char *fmtname = "";
1685 
1686 		switch (sbi->s_jquota_fmt) {
1687 		case QFMT_VFS_OLD:
1688 			fmtname = "vfsold";
1689 			break;
1690 		case QFMT_VFS_V0:
1691 			fmtname = "vfsv0";
1692 			break;
1693 		case QFMT_VFS_V1:
1694 			fmtname = "vfsv1";
1695 			break;
1696 		}
1697 		seq_printf(seq, ",jqfmt=%s", fmtname);
1698 	}
1699 
1700 	if (sbi->s_qf_names[USRQUOTA])
1701 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1702 
1703 	if (sbi->s_qf_names[GRPQUOTA])
1704 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1705 #endif
1706 }
1707 
1708 static const char *token2str(int token)
1709 {
1710 	const struct match_token *t;
1711 
1712 	for (t = tokens; t->token != Opt_err; t++)
1713 		if (t->token == token && !strchr(t->pattern, '='))
1714 			break;
1715 	return t->pattern;
1716 }
1717 
1718 /*
1719  * Show an option if
1720  *  - it's set to a non-default value OR
1721  *  - if the per-sb default is different from the global default
1722  */
1723 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1724 			      int nodefs)
1725 {
1726 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1727 	struct ext4_super_block *es = sbi->s_es;
1728 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1729 	const struct mount_opts *m;
1730 	char sep = nodefs ? '\n' : ',';
1731 
1732 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1733 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1734 
1735 	if (sbi->s_sb_block != 1)
1736 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1737 
1738 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1739 		int want_set = m->flags & MOPT_SET;
1740 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1741 		    (m->flags & MOPT_CLEAR_ERR))
1742 			continue;
1743 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1744 			continue; /* skip if same as the default */
1745 		if ((want_set &&
1746 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1747 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1748 			continue; /* select Opt_noFoo vs Opt_Foo */
1749 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1750 	}
1751 
1752 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1753 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1754 		SEQ_OPTS_PRINT("resuid=%u",
1755 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1756 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1757 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1758 		SEQ_OPTS_PRINT("resgid=%u",
1759 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1760 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1761 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1762 		SEQ_OPTS_PUTS("errors=remount-ro");
1763 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1764 		SEQ_OPTS_PUTS("errors=continue");
1765 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1766 		SEQ_OPTS_PUTS("errors=panic");
1767 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1768 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1769 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1770 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1771 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1772 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1773 	if (sb->s_flags & MS_I_VERSION)
1774 		SEQ_OPTS_PUTS("i_version");
1775 	if (nodefs || sbi->s_stripe)
1776 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1777 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1778 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1779 			SEQ_OPTS_PUTS("data=journal");
1780 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1781 			SEQ_OPTS_PUTS("data=ordered");
1782 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1783 			SEQ_OPTS_PUTS("data=writeback");
1784 	}
1785 	if (nodefs ||
1786 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1787 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1788 			       sbi->s_inode_readahead_blks);
1789 
1790 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1791 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1792 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1793 	if (nodefs || sbi->s_max_dir_size_kb)
1794 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1795 
1796 	ext4_show_quota_options(seq, sb);
1797 	return 0;
1798 }
1799 
1800 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1801 {
1802 	return _ext4_show_options(seq, root->d_sb, 0);
1803 }
1804 
1805 static int options_seq_show(struct seq_file *seq, void *offset)
1806 {
1807 	struct super_block *sb = seq->private;
1808 	int rc;
1809 
1810 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1811 	rc = _ext4_show_options(seq, sb, 1);
1812 	seq_puts(seq, "\n");
1813 	return rc;
1814 }
1815 
1816 static int options_open_fs(struct inode *inode, struct file *file)
1817 {
1818 	return single_open(file, options_seq_show, PDE_DATA(inode));
1819 }
1820 
1821 static const struct file_operations ext4_seq_options_fops = {
1822 	.owner = THIS_MODULE,
1823 	.open = options_open_fs,
1824 	.read = seq_read,
1825 	.llseek = seq_lseek,
1826 	.release = single_release,
1827 };
1828 
1829 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1830 			    int read_only)
1831 {
1832 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1833 	int res = 0;
1834 
1835 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1836 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1837 			 "forcing read-only mode");
1838 		res = MS_RDONLY;
1839 	}
1840 	if (read_only)
1841 		goto done;
1842 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1843 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1844 			 "running e2fsck is recommended");
1845 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1846 		ext4_msg(sb, KERN_WARNING,
1847 			 "warning: mounting fs with errors, "
1848 			 "running e2fsck is recommended");
1849 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1850 		 le16_to_cpu(es->s_mnt_count) >=
1851 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1852 		ext4_msg(sb, KERN_WARNING,
1853 			 "warning: maximal mount count reached, "
1854 			 "running e2fsck is recommended");
1855 	else if (le32_to_cpu(es->s_checkinterval) &&
1856 		(le32_to_cpu(es->s_lastcheck) +
1857 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1858 		ext4_msg(sb, KERN_WARNING,
1859 			 "warning: checktime reached, "
1860 			 "running e2fsck is recommended");
1861 	if (!sbi->s_journal)
1862 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1863 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1864 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1865 	le16_add_cpu(&es->s_mnt_count, 1);
1866 	es->s_mtime = cpu_to_le32(get_seconds());
1867 	ext4_update_dynamic_rev(sb);
1868 	if (sbi->s_journal)
1869 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1870 
1871 	ext4_commit_super(sb, 1);
1872 done:
1873 	if (test_opt(sb, DEBUG))
1874 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1875 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1876 			sb->s_blocksize,
1877 			sbi->s_groups_count,
1878 			EXT4_BLOCKS_PER_GROUP(sb),
1879 			EXT4_INODES_PER_GROUP(sb),
1880 			sbi->s_mount_opt, sbi->s_mount_opt2);
1881 
1882 	cleancache_init_fs(sb);
1883 	return res;
1884 }
1885 
1886 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1887 {
1888 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1889 	struct flex_groups *new_groups;
1890 	int size;
1891 
1892 	if (!sbi->s_log_groups_per_flex)
1893 		return 0;
1894 
1895 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1896 	if (size <= sbi->s_flex_groups_allocated)
1897 		return 0;
1898 
1899 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1900 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1901 	if (!new_groups) {
1902 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1903 			 size / (int) sizeof(struct flex_groups));
1904 		return -ENOMEM;
1905 	}
1906 
1907 	if (sbi->s_flex_groups) {
1908 		memcpy(new_groups, sbi->s_flex_groups,
1909 		       (sbi->s_flex_groups_allocated *
1910 			sizeof(struct flex_groups)));
1911 		ext4_kvfree(sbi->s_flex_groups);
1912 	}
1913 	sbi->s_flex_groups = new_groups;
1914 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1915 	return 0;
1916 }
1917 
1918 static int ext4_fill_flex_info(struct super_block *sb)
1919 {
1920 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1921 	struct ext4_group_desc *gdp = NULL;
1922 	ext4_group_t flex_group;
1923 	int i, err;
1924 
1925 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1926 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1927 		sbi->s_log_groups_per_flex = 0;
1928 		return 1;
1929 	}
1930 
1931 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1932 	if (err)
1933 		goto failed;
1934 
1935 	for (i = 0; i < sbi->s_groups_count; i++) {
1936 		gdp = ext4_get_group_desc(sb, i, NULL);
1937 
1938 		flex_group = ext4_flex_group(sbi, i);
1939 		atomic_add(ext4_free_inodes_count(sb, gdp),
1940 			   &sbi->s_flex_groups[flex_group].free_inodes);
1941 		atomic64_add(ext4_free_group_clusters(sb, gdp),
1942 			     &sbi->s_flex_groups[flex_group].free_clusters);
1943 		atomic_add(ext4_used_dirs_count(sb, gdp),
1944 			   &sbi->s_flex_groups[flex_group].used_dirs);
1945 	}
1946 
1947 	return 1;
1948 failed:
1949 	return 0;
1950 }
1951 
1952 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1953 				   struct ext4_group_desc *gdp)
1954 {
1955 	int offset;
1956 	__u16 crc = 0;
1957 	__le32 le_group = cpu_to_le32(block_group);
1958 
1959 	if ((sbi->s_es->s_feature_ro_compat &
1960 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1961 		/* Use new metadata_csum algorithm */
1962 		__le16 save_csum;
1963 		__u32 csum32;
1964 
1965 		save_csum = gdp->bg_checksum;
1966 		gdp->bg_checksum = 0;
1967 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1968 				     sizeof(le_group));
1969 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1970 				     sbi->s_desc_size);
1971 		gdp->bg_checksum = save_csum;
1972 
1973 		crc = csum32 & 0xFFFF;
1974 		goto out;
1975 	}
1976 
1977 	/* old crc16 code */
1978 	offset = offsetof(struct ext4_group_desc, bg_checksum);
1979 
1980 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1981 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1982 	crc = crc16(crc, (__u8 *)gdp, offset);
1983 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
1984 	/* for checksum of struct ext4_group_desc do the rest...*/
1985 	if ((sbi->s_es->s_feature_incompat &
1986 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1987 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1988 		crc = crc16(crc, (__u8 *)gdp + offset,
1989 			    le16_to_cpu(sbi->s_es->s_desc_size) -
1990 				offset);
1991 
1992 out:
1993 	return cpu_to_le16(crc);
1994 }
1995 
1996 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
1997 				struct ext4_group_desc *gdp)
1998 {
1999 	if (ext4_has_group_desc_csum(sb) &&
2000 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2001 						      block_group, gdp)))
2002 		return 0;
2003 
2004 	return 1;
2005 }
2006 
2007 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2008 			      struct ext4_group_desc *gdp)
2009 {
2010 	if (!ext4_has_group_desc_csum(sb))
2011 		return;
2012 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2013 }
2014 
2015 /* Called at mount-time, super-block is locked */
2016 static int ext4_check_descriptors(struct super_block *sb,
2017 				  ext4_group_t *first_not_zeroed)
2018 {
2019 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2020 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2021 	ext4_fsblk_t last_block;
2022 	ext4_fsblk_t block_bitmap;
2023 	ext4_fsblk_t inode_bitmap;
2024 	ext4_fsblk_t inode_table;
2025 	int flexbg_flag = 0;
2026 	ext4_group_t i, grp = sbi->s_groups_count;
2027 
2028 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2029 		flexbg_flag = 1;
2030 
2031 	ext4_debug("Checking group descriptors");
2032 
2033 	for (i = 0; i < sbi->s_groups_count; i++) {
2034 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2035 
2036 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2037 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2038 		else
2039 			last_block = first_block +
2040 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2041 
2042 		if ((grp == sbi->s_groups_count) &&
2043 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2044 			grp = i;
2045 
2046 		block_bitmap = ext4_block_bitmap(sb, gdp);
2047 		if (block_bitmap < first_block || block_bitmap > last_block) {
2048 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2049 			       "Block bitmap for group %u not in group "
2050 			       "(block %llu)!", i, block_bitmap);
2051 			return 0;
2052 		}
2053 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2054 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2055 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2056 			       "Inode bitmap for group %u not in group "
2057 			       "(block %llu)!", i, inode_bitmap);
2058 			return 0;
2059 		}
2060 		inode_table = ext4_inode_table(sb, gdp);
2061 		if (inode_table < first_block ||
2062 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2063 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2064 			       "Inode table for group %u not in group "
2065 			       "(block %llu)!", i, inode_table);
2066 			return 0;
2067 		}
2068 		ext4_lock_group(sb, i);
2069 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2070 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2071 				 "Checksum for group %u failed (%u!=%u)",
2072 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2073 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2074 			if (!(sb->s_flags & MS_RDONLY)) {
2075 				ext4_unlock_group(sb, i);
2076 				return 0;
2077 			}
2078 		}
2079 		ext4_unlock_group(sb, i);
2080 		if (!flexbg_flag)
2081 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2082 	}
2083 	if (NULL != first_not_zeroed)
2084 		*first_not_zeroed = grp;
2085 
2086 	ext4_free_blocks_count_set(sbi->s_es,
2087 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2088 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2089 	return 1;
2090 }
2091 
2092 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2093  * the superblock) which were deleted from all directories, but held open by
2094  * a process at the time of a crash.  We walk the list and try to delete these
2095  * inodes at recovery time (only with a read-write filesystem).
2096  *
2097  * In order to keep the orphan inode chain consistent during traversal (in
2098  * case of crash during recovery), we link each inode into the superblock
2099  * orphan list_head and handle it the same way as an inode deletion during
2100  * normal operation (which journals the operations for us).
2101  *
2102  * We only do an iget() and an iput() on each inode, which is very safe if we
2103  * accidentally point at an in-use or already deleted inode.  The worst that
2104  * can happen in this case is that we get a "bit already cleared" message from
2105  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2106  * e2fsck was run on this filesystem, and it must have already done the orphan
2107  * inode cleanup for us, so we can safely abort without any further action.
2108  */
2109 static void ext4_orphan_cleanup(struct super_block *sb,
2110 				struct ext4_super_block *es)
2111 {
2112 	unsigned int s_flags = sb->s_flags;
2113 	int nr_orphans = 0, nr_truncates = 0;
2114 #ifdef CONFIG_QUOTA
2115 	int i;
2116 #endif
2117 	if (!es->s_last_orphan) {
2118 		jbd_debug(4, "no orphan inodes to clean up\n");
2119 		return;
2120 	}
2121 
2122 	if (bdev_read_only(sb->s_bdev)) {
2123 		ext4_msg(sb, KERN_ERR, "write access "
2124 			"unavailable, skipping orphan cleanup");
2125 		return;
2126 	}
2127 
2128 	/* Check if feature set would not allow a r/w mount */
2129 	if (!ext4_feature_set_ok(sb, 0)) {
2130 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2131 			 "unknown ROCOMPAT features");
2132 		return;
2133 	}
2134 
2135 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2136 		/* don't clear list on RO mount w/ errors */
2137 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2138 			jbd_debug(1, "Errors on filesystem, "
2139 				  "clearing orphan list.\n");
2140 			es->s_last_orphan = 0;
2141 		}
2142 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2143 		return;
2144 	}
2145 
2146 	if (s_flags & MS_RDONLY) {
2147 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2148 		sb->s_flags &= ~MS_RDONLY;
2149 	}
2150 #ifdef CONFIG_QUOTA
2151 	/* Needed for iput() to work correctly and not trash data */
2152 	sb->s_flags |= MS_ACTIVE;
2153 	/* Turn on quotas so that they are updated correctly */
2154 	for (i = 0; i < MAXQUOTAS; i++) {
2155 		if (EXT4_SB(sb)->s_qf_names[i]) {
2156 			int ret = ext4_quota_on_mount(sb, i);
2157 			if (ret < 0)
2158 				ext4_msg(sb, KERN_ERR,
2159 					"Cannot turn on journaled "
2160 					"quota: error %d", ret);
2161 		}
2162 	}
2163 #endif
2164 
2165 	while (es->s_last_orphan) {
2166 		struct inode *inode;
2167 
2168 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2169 		if (IS_ERR(inode)) {
2170 			es->s_last_orphan = 0;
2171 			break;
2172 		}
2173 
2174 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2175 		dquot_initialize(inode);
2176 		if (inode->i_nlink) {
2177 			if (test_opt(sb, DEBUG))
2178 				ext4_msg(sb, KERN_DEBUG,
2179 					"%s: truncating inode %lu to %lld bytes",
2180 					__func__, inode->i_ino, inode->i_size);
2181 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2182 				  inode->i_ino, inode->i_size);
2183 			mutex_lock(&inode->i_mutex);
2184 			truncate_inode_pages(inode->i_mapping, inode->i_size);
2185 			ext4_truncate(inode);
2186 			mutex_unlock(&inode->i_mutex);
2187 			nr_truncates++;
2188 		} else {
2189 			if (test_opt(sb, DEBUG))
2190 				ext4_msg(sb, KERN_DEBUG,
2191 					"%s: deleting unreferenced inode %lu",
2192 					__func__, inode->i_ino);
2193 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2194 				  inode->i_ino);
2195 			nr_orphans++;
2196 		}
2197 		iput(inode);  /* The delete magic happens here! */
2198 	}
2199 
2200 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2201 
2202 	if (nr_orphans)
2203 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2204 		       PLURAL(nr_orphans));
2205 	if (nr_truncates)
2206 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2207 		       PLURAL(nr_truncates));
2208 #ifdef CONFIG_QUOTA
2209 	/* Turn quotas off */
2210 	for (i = 0; i < MAXQUOTAS; i++) {
2211 		if (sb_dqopt(sb)->files[i])
2212 			dquot_quota_off(sb, i);
2213 	}
2214 #endif
2215 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2216 }
2217 
2218 /*
2219  * Maximal extent format file size.
2220  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2221  * extent format containers, within a sector_t, and within i_blocks
2222  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2223  * so that won't be a limiting factor.
2224  *
2225  * However there is other limiting factor. We do store extents in the form
2226  * of starting block and length, hence the resulting length of the extent
2227  * covering maximum file size must fit into on-disk format containers as
2228  * well. Given that length is always by 1 unit bigger than max unit (because
2229  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2230  *
2231  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2232  */
2233 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2234 {
2235 	loff_t res;
2236 	loff_t upper_limit = MAX_LFS_FILESIZE;
2237 
2238 	/* small i_blocks in vfs inode? */
2239 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2240 		/*
2241 		 * CONFIG_LBDAF is not enabled implies the inode
2242 		 * i_block represent total blocks in 512 bytes
2243 		 * 32 == size of vfs inode i_blocks * 8
2244 		 */
2245 		upper_limit = (1LL << 32) - 1;
2246 
2247 		/* total blocks in file system block size */
2248 		upper_limit >>= (blkbits - 9);
2249 		upper_limit <<= blkbits;
2250 	}
2251 
2252 	/*
2253 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2254 	 * by one fs block, so ee_len can cover the extent of maximum file
2255 	 * size
2256 	 */
2257 	res = (1LL << 32) - 1;
2258 	res <<= blkbits;
2259 
2260 	/* Sanity check against vm- & vfs- imposed limits */
2261 	if (res > upper_limit)
2262 		res = upper_limit;
2263 
2264 	return res;
2265 }
2266 
2267 /*
2268  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2269  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2270  * We need to be 1 filesystem block less than the 2^48 sector limit.
2271  */
2272 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2273 {
2274 	loff_t res = EXT4_NDIR_BLOCKS;
2275 	int meta_blocks;
2276 	loff_t upper_limit;
2277 	/* This is calculated to be the largest file size for a dense, block
2278 	 * mapped file such that the file's total number of 512-byte sectors,
2279 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2280 	 *
2281 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2282 	 * number of 512-byte sectors of the file.
2283 	 */
2284 
2285 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2286 		/*
2287 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2288 		 * the inode i_block field represents total file blocks in
2289 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2290 		 */
2291 		upper_limit = (1LL << 32) - 1;
2292 
2293 		/* total blocks in file system block size */
2294 		upper_limit >>= (bits - 9);
2295 
2296 	} else {
2297 		/*
2298 		 * We use 48 bit ext4_inode i_blocks
2299 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2300 		 * represent total number of blocks in
2301 		 * file system block size
2302 		 */
2303 		upper_limit = (1LL << 48) - 1;
2304 
2305 	}
2306 
2307 	/* indirect blocks */
2308 	meta_blocks = 1;
2309 	/* double indirect blocks */
2310 	meta_blocks += 1 + (1LL << (bits-2));
2311 	/* tripple indirect blocks */
2312 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2313 
2314 	upper_limit -= meta_blocks;
2315 	upper_limit <<= bits;
2316 
2317 	res += 1LL << (bits-2);
2318 	res += 1LL << (2*(bits-2));
2319 	res += 1LL << (3*(bits-2));
2320 	res <<= bits;
2321 	if (res > upper_limit)
2322 		res = upper_limit;
2323 
2324 	if (res > MAX_LFS_FILESIZE)
2325 		res = MAX_LFS_FILESIZE;
2326 
2327 	return res;
2328 }
2329 
2330 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2331 				   ext4_fsblk_t logical_sb_block, int nr)
2332 {
2333 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2334 	ext4_group_t bg, first_meta_bg;
2335 	int has_super = 0;
2336 
2337 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2338 
2339 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2340 	    nr < first_meta_bg)
2341 		return logical_sb_block + nr + 1;
2342 	bg = sbi->s_desc_per_block * nr;
2343 	if (ext4_bg_has_super(sb, bg))
2344 		has_super = 1;
2345 
2346 	return (has_super + ext4_group_first_block_no(sb, bg));
2347 }
2348 
2349 /**
2350  * ext4_get_stripe_size: Get the stripe size.
2351  * @sbi: In memory super block info
2352  *
2353  * If we have specified it via mount option, then
2354  * use the mount option value. If the value specified at mount time is
2355  * greater than the blocks per group use the super block value.
2356  * If the super block value is greater than blocks per group return 0.
2357  * Allocator needs it be less than blocks per group.
2358  *
2359  */
2360 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2361 {
2362 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2363 	unsigned long stripe_width =
2364 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2365 	int ret;
2366 
2367 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2368 		ret = sbi->s_stripe;
2369 	else if (stripe_width <= sbi->s_blocks_per_group)
2370 		ret = stripe_width;
2371 	else if (stride <= sbi->s_blocks_per_group)
2372 		ret = stride;
2373 	else
2374 		ret = 0;
2375 
2376 	/*
2377 	 * If the stripe width is 1, this makes no sense and
2378 	 * we set it to 0 to turn off stripe handling code.
2379 	 */
2380 	if (ret <= 1)
2381 		ret = 0;
2382 
2383 	return ret;
2384 }
2385 
2386 /* sysfs supprt */
2387 
2388 struct ext4_attr {
2389 	struct attribute attr;
2390 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2391 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2392 			 const char *, size_t);
2393 	union {
2394 		int offset;
2395 		int deprecated_val;
2396 	} u;
2397 };
2398 
2399 static int parse_strtoull(const char *buf,
2400 		unsigned long long max, unsigned long long *value)
2401 {
2402 	int ret;
2403 
2404 	ret = kstrtoull(skip_spaces(buf), 0, value);
2405 	if (!ret && *value > max)
2406 		ret = -EINVAL;
2407 	return ret;
2408 }
2409 
2410 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2411 					      struct ext4_sb_info *sbi,
2412 					      char *buf)
2413 {
2414 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2415 		(s64) EXT4_C2B(sbi,
2416 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2417 }
2418 
2419 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2420 					 struct ext4_sb_info *sbi, char *buf)
2421 {
2422 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2423 
2424 	if (!sb->s_bdev->bd_part)
2425 		return snprintf(buf, PAGE_SIZE, "0\n");
2426 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2427 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2428 			 sbi->s_sectors_written_start) >> 1);
2429 }
2430 
2431 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2432 					  struct ext4_sb_info *sbi, char *buf)
2433 {
2434 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2435 
2436 	if (!sb->s_bdev->bd_part)
2437 		return snprintf(buf, PAGE_SIZE, "0\n");
2438 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2439 			(unsigned long long)(sbi->s_kbytes_written +
2440 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2441 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2442 }
2443 
2444 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2445 					  struct ext4_sb_info *sbi,
2446 					  const char *buf, size_t count)
2447 {
2448 	unsigned long t;
2449 	int ret;
2450 
2451 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2452 	if (ret)
2453 		return ret;
2454 
2455 	if (t && (!is_power_of_2(t) || t > 0x40000000))
2456 		return -EINVAL;
2457 
2458 	sbi->s_inode_readahead_blks = t;
2459 	return count;
2460 }
2461 
2462 static ssize_t sbi_ui_show(struct ext4_attr *a,
2463 			   struct ext4_sb_info *sbi, char *buf)
2464 {
2465 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2466 
2467 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2468 }
2469 
2470 static ssize_t sbi_ui_store(struct ext4_attr *a,
2471 			    struct ext4_sb_info *sbi,
2472 			    const char *buf, size_t count)
2473 {
2474 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
2475 	unsigned long t;
2476 	int ret;
2477 
2478 	ret = kstrtoul(skip_spaces(buf), 0, &t);
2479 	if (ret)
2480 		return ret;
2481 	*ui = t;
2482 	return count;
2483 }
2484 
2485 static ssize_t reserved_clusters_show(struct ext4_attr *a,
2486 				  struct ext4_sb_info *sbi, char *buf)
2487 {
2488 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2489 		(unsigned long long) atomic64_read(&sbi->s_resv_clusters));
2490 }
2491 
2492 static ssize_t reserved_clusters_store(struct ext4_attr *a,
2493 				   struct ext4_sb_info *sbi,
2494 				   const char *buf, size_t count)
2495 {
2496 	unsigned long long val;
2497 	int ret;
2498 
2499 	if (parse_strtoull(buf, -1ULL, &val))
2500 		return -EINVAL;
2501 	ret = ext4_reserve_clusters(sbi, val);
2502 
2503 	return ret ? ret : count;
2504 }
2505 
2506 static ssize_t trigger_test_error(struct ext4_attr *a,
2507 				  struct ext4_sb_info *sbi,
2508 				  const char *buf, size_t count)
2509 {
2510 	int len = count;
2511 
2512 	if (!capable(CAP_SYS_ADMIN))
2513 		return -EPERM;
2514 
2515 	if (len && buf[len-1] == '\n')
2516 		len--;
2517 
2518 	if (len)
2519 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2520 	return count;
2521 }
2522 
2523 static ssize_t sbi_deprecated_show(struct ext4_attr *a,
2524 				   struct ext4_sb_info *sbi, char *buf)
2525 {
2526 	return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
2527 }
2528 
2529 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2530 static struct ext4_attr ext4_attr_##_name = {			\
2531 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2532 	.show	= _show,					\
2533 	.store	= _store,					\
2534 	.u = {							\
2535 		.offset = offsetof(struct ext4_sb_info, _elname),\
2536 	},							\
2537 }
2538 #define EXT4_ATTR(name, mode, show, store) \
2539 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2540 
2541 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2542 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2543 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2544 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2545 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2546 #define ATTR_LIST(name) &ext4_attr_##name.attr
2547 #define EXT4_DEPRECATED_ATTR(_name, _val)	\
2548 static struct ext4_attr ext4_attr_##_name = {			\
2549 	.attr = {.name = __stringify(_name), .mode = 0444 },	\
2550 	.show	= sbi_deprecated_show,				\
2551 	.u = {							\
2552 		.deprecated_val = _val,				\
2553 	},							\
2554 }
2555 
2556 EXT4_RO_ATTR(delayed_allocation_blocks);
2557 EXT4_RO_ATTR(session_write_kbytes);
2558 EXT4_RO_ATTR(lifetime_write_kbytes);
2559 EXT4_RW_ATTR(reserved_clusters);
2560 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2561 		 inode_readahead_blks_store, s_inode_readahead_blks);
2562 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2563 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2564 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2565 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2566 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2567 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2568 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2569 EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
2570 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2571 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2572 
2573 static struct attribute *ext4_attrs[] = {
2574 	ATTR_LIST(delayed_allocation_blocks),
2575 	ATTR_LIST(session_write_kbytes),
2576 	ATTR_LIST(lifetime_write_kbytes),
2577 	ATTR_LIST(reserved_clusters),
2578 	ATTR_LIST(inode_readahead_blks),
2579 	ATTR_LIST(inode_goal),
2580 	ATTR_LIST(mb_stats),
2581 	ATTR_LIST(mb_max_to_scan),
2582 	ATTR_LIST(mb_min_to_scan),
2583 	ATTR_LIST(mb_order2_req),
2584 	ATTR_LIST(mb_stream_req),
2585 	ATTR_LIST(mb_group_prealloc),
2586 	ATTR_LIST(max_writeback_mb_bump),
2587 	ATTR_LIST(extent_max_zeroout_kb),
2588 	ATTR_LIST(trigger_fs_error),
2589 	NULL,
2590 };
2591 
2592 /* Features this copy of ext4 supports */
2593 EXT4_INFO_ATTR(lazy_itable_init);
2594 EXT4_INFO_ATTR(batched_discard);
2595 EXT4_INFO_ATTR(meta_bg_resize);
2596 
2597 static struct attribute *ext4_feat_attrs[] = {
2598 	ATTR_LIST(lazy_itable_init),
2599 	ATTR_LIST(batched_discard),
2600 	ATTR_LIST(meta_bg_resize),
2601 	NULL,
2602 };
2603 
2604 static ssize_t ext4_attr_show(struct kobject *kobj,
2605 			      struct attribute *attr, char *buf)
2606 {
2607 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2608 						s_kobj);
2609 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2610 
2611 	return a->show ? a->show(a, sbi, buf) : 0;
2612 }
2613 
2614 static ssize_t ext4_attr_store(struct kobject *kobj,
2615 			       struct attribute *attr,
2616 			       const char *buf, size_t len)
2617 {
2618 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2619 						s_kobj);
2620 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2621 
2622 	return a->store ? a->store(a, sbi, buf, len) : 0;
2623 }
2624 
2625 static void ext4_sb_release(struct kobject *kobj)
2626 {
2627 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2628 						s_kobj);
2629 	complete(&sbi->s_kobj_unregister);
2630 }
2631 
2632 static const struct sysfs_ops ext4_attr_ops = {
2633 	.show	= ext4_attr_show,
2634 	.store	= ext4_attr_store,
2635 };
2636 
2637 static struct kobj_type ext4_ktype = {
2638 	.default_attrs	= ext4_attrs,
2639 	.sysfs_ops	= &ext4_attr_ops,
2640 	.release	= ext4_sb_release,
2641 };
2642 
2643 static void ext4_feat_release(struct kobject *kobj)
2644 {
2645 	complete(&ext4_feat->f_kobj_unregister);
2646 }
2647 
2648 static struct kobj_type ext4_feat_ktype = {
2649 	.default_attrs	= ext4_feat_attrs,
2650 	.sysfs_ops	= &ext4_attr_ops,
2651 	.release	= ext4_feat_release,
2652 };
2653 
2654 /*
2655  * Check whether this filesystem can be mounted based on
2656  * the features present and the RDONLY/RDWR mount requested.
2657  * Returns 1 if this filesystem can be mounted as requested,
2658  * 0 if it cannot be.
2659  */
2660 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2661 {
2662 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2663 		ext4_msg(sb, KERN_ERR,
2664 			"Couldn't mount because of "
2665 			"unsupported optional features (%x)",
2666 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2667 			~EXT4_FEATURE_INCOMPAT_SUPP));
2668 		return 0;
2669 	}
2670 
2671 	if (readonly)
2672 		return 1;
2673 
2674 	/* Check that feature set is OK for a read-write mount */
2675 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2676 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2677 			 "unsupported optional features (%x)",
2678 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2679 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2680 		return 0;
2681 	}
2682 	/*
2683 	 * Large file size enabled file system can only be mounted
2684 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2685 	 */
2686 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2687 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2688 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2689 				 "cannot be mounted RDWR without "
2690 				 "CONFIG_LBDAF");
2691 			return 0;
2692 		}
2693 	}
2694 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2695 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2696 		ext4_msg(sb, KERN_ERR,
2697 			 "Can't support bigalloc feature without "
2698 			 "extents feature\n");
2699 		return 0;
2700 	}
2701 
2702 #ifndef CONFIG_QUOTA
2703 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2704 	    !readonly) {
2705 		ext4_msg(sb, KERN_ERR,
2706 			 "Filesystem with quota feature cannot be mounted RDWR "
2707 			 "without CONFIG_QUOTA");
2708 		return 0;
2709 	}
2710 #endif  /* CONFIG_QUOTA */
2711 	return 1;
2712 }
2713 
2714 /*
2715  * This function is called once a day if we have errors logged
2716  * on the file system
2717  */
2718 static void print_daily_error_info(unsigned long arg)
2719 {
2720 	struct super_block *sb = (struct super_block *) arg;
2721 	struct ext4_sb_info *sbi;
2722 	struct ext4_super_block *es;
2723 
2724 	sbi = EXT4_SB(sb);
2725 	es = sbi->s_es;
2726 
2727 	if (es->s_error_count)
2728 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2729 			 le32_to_cpu(es->s_error_count));
2730 	if (es->s_first_error_time) {
2731 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2732 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2733 		       (int) sizeof(es->s_first_error_func),
2734 		       es->s_first_error_func,
2735 		       le32_to_cpu(es->s_first_error_line));
2736 		if (es->s_first_error_ino)
2737 			printk(": inode %u",
2738 			       le32_to_cpu(es->s_first_error_ino));
2739 		if (es->s_first_error_block)
2740 			printk(": block %llu", (unsigned long long)
2741 			       le64_to_cpu(es->s_first_error_block));
2742 		printk("\n");
2743 	}
2744 	if (es->s_last_error_time) {
2745 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2746 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2747 		       (int) sizeof(es->s_last_error_func),
2748 		       es->s_last_error_func,
2749 		       le32_to_cpu(es->s_last_error_line));
2750 		if (es->s_last_error_ino)
2751 			printk(": inode %u",
2752 			       le32_to_cpu(es->s_last_error_ino));
2753 		if (es->s_last_error_block)
2754 			printk(": block %llu", (unsigned long long)
2755 			       le64_to_cpu(es->s_last_error_block));
2756 		printk("\n");
2757 	}
2758 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2759 }
2760 
2761 /* Find next suitable group and run ext4_init_inode_table */
2762 static int ext4_run_li_request(struct ext4_li_request *elr)
2763 {
2764 	struct ext4_group_desc *gdp = NULL;
2765 	ext4_group_t group, ngroups;
2766 	struct super_block *sb;
2767 	unsigned long timeout = 0;
2768 	int ret = 0;
2769 
2770 	sb = elr->lr_super;
2771 	ngroups = EXT4_SB(sb)->s_groups_count;
2772 
2773 	sb_start_write(sb);
2774 	for (group = elr->lr_next_group; group < ngroups; group++) {
2775 		gdp = ext4_get_group_desc(sb, group, NULL);
2776 		if (!gdp) {
2777 			ret = 1;
2778 			break;
2779 		}
2780 
2781 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2782 			break;
2783 	}
2784 
2785 	if (group >= ngroups)
2786 		ret = 1;
2787 
2788 	if (!ret) {
2789 		timeout = jiffies;
2790 		ret = ext4_init_inode_table(sb, group,
2791 					    elr->lr_timeout ? 0 : 1);
2792 		if (elr->lr_timeout == 0) {
2793 			timeout = (jiffies - timeout) *
2794 				  elr->lr_sbi->s_li_wait_mult;
2795 			elr->lr_timeout = timeout;
2796 		}
2797 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2798 		elr->lr_next_group = group + 1;
2799 	}
2800 	sb_end_write(sb);
2801 
2802 	return ret;
2803 }
2804 
2805 /*
2806  * Remove lr_request from the list_request and free the
2807  * request structure. Should be called with li_list_mtx held
2808  */
2809 static void ext4_remove_li_request(struct ext4_li_request *elr)
2810 {
2811 	struct ext4_sb_info *sbi;
2812 
2813 	if (!elr)
2814 		return;
2815 
2816 	sbi = elr->lr_sbi;
2817 
2818 	list_del(&elr->lr_request);
2819 	sbi->s_li_request = NULL;
2820 	kfree(elr);
2821 }
2822 
2823 static void ext4_unregister_li_request(struct super_block *sb)
2824 {
2825 	mutex_lock(&ext4_li_mtx);
2826 	if (!ext4_li_info) {
2827 		mutex_unlock(&ext4_li_mtx);
2828 		return;
2829 	}
2830 
2831 	mutex_lock(&ext4_li_info->li_list_mtx);
2832 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2833 	mutex_unlock(&ext4_li_info->li_list_mtx);
2834 	mutex_unlock(&ext4_li_mtx);
2835 }
2836 
2837 static struct task_struct *ext4_lazyinit_task;
2838 
2839 /*
2840  * This is the function where ext4lazyinit thread lives. It walks
2841  * through the request list searching for next scheduled filesystem.
2842  * When such a fs is found, run the lazy initialization request
2843  * (ext4_rn_li_request) and keep track of the time spend in this
2844  * function. Based on that time we compute next schedule time of
2845  * the request. When walking through the list is complete, compute
2846  * next waking time and put itself into sleep.
2847  */
2848 static int ext4_lazyinit_thread(void *arg)
2849 {
2850 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2851 	struct list_head *pos, *n;
2852 	struct ext4_li_request *elr;
2853 	unsigned long next_wakeup, cur;
2854 
2855 	BUG_ON(NULL == eli);
2856 
2857 cont_thread:
2858 	while (true) {
2859 		next_wakeup = MAX_JIFFY_OFFSET;
2860 
2861 		mutex_lock(&eli->li_list_mtx);
2862 		if (list_empty(&eli->li_request_list)) {
2863 			mutex_unlock(&eli->li_list_mtx);
2864 			goto exit_thread;
2865 		}
2866 
2867 		list_for_each_safe(pos, n, &eli->li_request_list) {
2868 			elr = list_entry(pos, struct ext4_li_request,
2869 					 lr_request);
2870 
2871 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2872 				if (ext4_run_li_request(elr) != 0) {
2873 					/* error, remove the lazy_init job */
2874 					ext4_remove_li_request(elr);
2875 					continue;
2876 				}
2877 			}
2878 
2879 			if (time_before(elr->lr_next_sched, next_wakeup))
2880 				next_wakeup = elr->lr_next_sched;
2881 		}
2882 		mutex_unlock(&eli->li_list_mtx);
2883 
2884 		try_to_freeze();
2885 
2886 		cur = jiffies;
2887 		if ((time_after_eq(cur, next_wakeup)) ||
2888 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2889 			cond_resched();
2890 			continue;
2891 		}
2892 
2893 		schedule_timeout_interruptible(next_wakeup - cur);
2894 
2895 		if (kthread_should_stop()) {
2896 			ext4_clear_request_list();
2897 			goto exit_thread;
2898 		}
2899 	}
2900 
2901 exit_thread:
2902 	/*
2903 	 * It looks like the request list is empty, but we need
2904 	 * to check it under the li_list_mtx lock, to prevent any
2905 	 * additions into it, and of course we should lock ext4_li_mtx
2906 	 * to atomically free the list and ext4_li_info, because at
2907 	 * this point another ext4 filesystem could be registering
2908 	 * new one.
2909 	 */
2910 	mutex_lock(&ext4_li_mtx);
2911 	mutex_lock(&eli->li_list_mtx);
2912 	if (!list_empty(&eli->li_request_list)) {
2913 		mutex_unlock(&eli->li_list_mtx);
2914 		mutex_unlock(&ext4_li_mtx);
2915 		goto cont_thread;
2916 	}
2917 	mutex_unlock(&eli->li_list_mtx);
2918 	kfree(ext4_li_info);
2919 	ext4_li_info = NULL;
2920 	mutex_unlock(&ext4_li_mtx);
2921 
2922 	return 0;
2923 }
2924 
2925 static void ext4_clear_request_list(void)
2926 {
2927 	struct list_head *pos, *n;
2928 	struct ext4_li_request *elr;
2929 
2930 	mutex_lock(&ext4_li_info->li_list_mtx);
2931 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2932 		elr = list_entry(pos, struct ext4_li_request,
2933 				 lr_request);
2934 		ext4_remove_li_request(elr);
2935 	}
2936 	mutex_unlock(&ext4_li_info->li_list_mtx);
2937 }
2938 
2939 static int ext4_run_lazyinit_thread(void)
2940 {
2941 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2942 					 ext4_li_info, "ext4lazyinit");
2943 	if (IS_ERR(ext4_lazyinit_task)) {
2944 		int err = PTR_ERR(ext4_lazyinit_task);
2945 		ext4_clear_request_list();
2946 		kfree(ext4_li_info);
2947 		ext4_li_info = NULL;
2948 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2949 				 "initialization thread\n",
2950 				 err);
2951 		return err;
2952 	}
2953 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2954 	return 0;
2955 }
2956 
2957 /*
2958  * Check whether it make sense to run itable init. thread or not.
2959  * If there is at least one uninitialized inode table, return
2960  * corresponding group number, else the loop goes through all
2961  * groups and return total number of groups.
2962  */
2963 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2964 {
2965 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2966 	struct ext4_group_desc *gdp = NULL;
2967 
2968 	for (group = 0; group < ngroups; group++) {
2969 		gdp = ext4_get_group_desc(sb, group, NULL);
2970 		if (!gdp)
2971 			continue;
2972 
2973 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2974 			break;
2975 	}
2976 
2977 	return group;
2978 }
2979 
2980 static int ext4_li_info_new(void)
2981 {
2982 	struct ext4_lazy_init *eli = NULL;
2983 
2984 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2985 	if (!eli)
2986 		return -ENOMEM;
2987 
2988 	INIT_LIST_HEAD(&eli->li_request_list);
2989 	mutex_init(&eli->li_list_mtx);
2990 
2991 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2992 
2993 	ext4_li_info = eli;
2994 
2995 	return 0;
2996 }
2997 
2998 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2999 					    ext4_group_t start)
3000 {
3001 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3002 	struct ext4_li_request *elr;
3003 	unsigned long rnd;
3004 
3005 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
3006 	if (!elr)
3007 		return NULL;
3008 
3009 	elr->lr_super = sb;
3010 	elr->lr_sbi = sbi;
3011 	elr->lr_next_group = start;
3012 
3013 	/*
3014 	 * Randomize first schedule time of the request to
3015 	 * spread the inode table initialization requests
3016 	 * better.
3017 	 */
3018 	get_random_bytes(&rnd, sizeof(rnd));
3019 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
3020 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3021 
3022 	return elr;
3023 }
3024 
3025 int ext4_register_li_request(struct super_block *sb,
3026 			     ext4_group_t first_not_zeroed)
3027 {
3028 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3029 	struct ext4_li_request *elr = NULL;
3030 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3031 	int ret = 0;
3032 
3033 	mutex_lock(&ext4_li_mtx);
3034 	if (sbi->s_li_request != NULL) {
3035 		/*
3036 		 * Reset timeout so it can be computed again, because
3037 		 * s_li_wait_mult might have changed.
3038 		 */
3039 		sbi->s_li_request->lr_timeout = 0;
3040 		goto out;
3041 	}
3042 
3043 	if (first_not_zeroed == ngroups ||
3044 	    (sb->s_flags & MS_RDONLY) ||
3045 	    !test_opt(sb, INIT_INODE_TABLE))
3046 		goto out;
3047 
3048 	elr = ext4_li_request_new(sb, first_not_zeroed);
3049 	if (!elr) {
3050 		ret = -ENOMEM;
3051 		goto out;
3052 	}
3053 
3054 	if (NULL == ext4_li_info) {
3055 		ret = ext4_li_info_new();
3056 		if (ret)
3057 			goto out;
3058 	}
3059 
3060 	mutex_lock(&ext4_li_info->li_list_mtx);
3061 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3062 	mutex_unlock(&ext4_li_info->li_list_mtx);
3063 
3064 	sbi->s_li_request = elr;
3065 	/*
3066 	 * set elr to NULL here since it has been inserted to
3067 	 * the request_list and the removal and free of it is
3068 	 * handled by ext4_clear_request_list from now on.
3069 	 */
3070 	elr = NULL;
3071 
3072 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3073 		ret = ext4_run_lazyinit_thread();
3074 		if (ret)
3075 			goto out;
3076 	}
3077 out:
3078 	mutex_unlock(&ext4_li_mtx);
3079 	if (ret)
3080 		kfree(elr);
3081 	return ret;
3082 }
3083 
3084 /*
3085  * We do not need to lock anything since this is called on
3086  * module unload.
3087  */
3088 static void ext4_destroy_lazyinit_thread(void)
3089 {
3090 	/*
3091 	 * If thread exited earlier
3092 	 * there's nothing to be done.
3093 	 */
3094 	if (!ext4_li_info || !ext4_lazyinit_task)
3095 		return;
3096 
3097 	kthread_stop(ext4_lazyinit_task);
3098 }
3099 
3100 static int set_journal_csum_feature_set(struct super_block *sb)
3101 {
3102 	int ret = 1;
3103 	int compat, incompat;
3104 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3105 
3106 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3107 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3108 		/* journal checksum v2 */
3109 		compat = 0;
3110 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3111 	} else {
3112 		/* journal checksum v1 */
3113 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3114 		incompat = 0;
3115 	}
3116 
3117 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3118 		ret = jbd2_journal_set_features(sbi->s_journal,
3119 				compat, 0,
3120 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3121 				incompat);
3122 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3123 		ret = jbd2_journal_set_features(sbi->s_journal,
3124 				compat, 0,
3125 				incompat);
3126 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3127 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3128 	} else {
3129 		jbd2_journal_clear_features(sbi->s_journal,
3130 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3131 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3132 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3133 	}
3134 
3135 	return ret;
3136 }
3137 
3138 /*
3139  * Note: calculating the overhead so we can be compatible with
3140  * historical BSD practice is quite difficult in the face of
3141  * clusters/bigalloc.  This is because multiple metadata blocks from
3142  * different block group can end up in the same allocation cluster.
3143  * Calculating the exact overhead in the face of clustered allocation
3144  * requires either O(all block bitmaps) in memory or O(number of block
3145  * groups**2) in time.  We will still calculate the superblock for
3146  * older file systems --- and if we come across with a bigalloc file
3147  * system with zero in s_overhead_clusters the estimate will be close to
3148  * correct especially for very large cluster sizes --- but for newer
3149  * file systems, it's better to calculate this figure once at mkfs
3150  * time, and store it in the superblock.  If the superblock value is
3151  * present (even for non-bigalloc file systems), we will use it.
3152  */
3153 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3154 			  char *buf)
3155 {
3156 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3157 	struct ext4_group_desc	*gdp;
3158 	ext4_fsblk_t		first_block, last_block, b;
3159 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3160 	int			s, j, count = 0;
3161 
3162 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3163 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3164 			sbi->s_itb_per_group + 2);
3165 
3166 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3167 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3168 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3169 	for (i = 0; i < ngroups; i++) {
3170 		gdp = ext4_get_group_desc(sb, i, NULL);
3171 		b = ext4_block_bitmap(sb, gdp);
3172 		if (b >= first_block && b <= last_block) {
3173 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3174 			count++;
3175 		}
3176 		b = ext4_inode_bitmap(sb, gdp);
3177 		if (b >= first_block && b <= last_block) {
3178 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3179 			count++;
3180 		}
3181 		b = ext4_inode_table(sb, gdp);
3182 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3183 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3184 				int c = EXT4_B2C(sbi, b - first_block);
3185 				ext4_set_bit(c, buf);
3186 				count++;
3187 			}
3188 		if (i != grp)
3189 			continue;
3190 		s = 0;
3191 		if (ext4_bg_has_super(sb, grp)) {
3192 			ext4_set_bit(s++, buf);
3193 			count++;
3194 		}
3195 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3196 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3197 			count++;
3198 		}
3199 	}
3200 	if (!count)
3201 		return 0;
3202 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3203 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3204 }
3205 
3206 /*
3207  * Compute the overhead and stash it in sbi->s_overhead
3208  */
3209 int ext4_calculate_overhead(struct super_block *sb)
3210 {
3211 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3212 	struct ext4_super_block *es = sbi->s_es;
3213 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3214 	ext4_fsblk_t overhead = 0;
3215 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3216 
3217 	if (!buf)
3218 		return -ENOMEM;
3219 
3220 	/*
3221 	 * Compute the overhead (FS structures).  This is constant
3222 	 * for a given filesystem unless the number of block groups
3223 	 * changes so we cache the previous value until it does.
3224 	 */
3225 
3226 	/*
3227 	 * All of the blocks before first_data_block are overhead
3228 	 */
3229 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3230 
3231 	/*
3232 	 * Add the overhead found in each block group
3233 	 */
3234 	for (i = 0; i < ngroups; i++) {
3235 		int blks;
3236 
3237 		blks = count_overhead(sb, i, buf);
3238 		overhead += blks;
3239 		if (blks)
3240 			memset(buf, 0, PAGE_SIZE);
3241 		cond_resched();
3242 	}
3243 	/* Add the journal blocks as well */
3244 	if (sbi->s_journal)
3245 		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
3246 
3247 	sbi->s_overhead = overhead;
3248 	smp_wmb();
3249 	free_page((unsigned long) buf);
3250 	return 0;
3251 }
3252 
3253 
3254 static ext4_fsblk_t ext4_calculate_resv_clusters(struct ext4_sb_info *sbi)
3255 {
3256 	ext4_fsblk_t resv_clusters;
3257 
3258 	/*
3259 	 * By default we reserve 2% or 4096 clusters, whichever is smaller.
3260 	 * This should cover the situations where we can not afford to run
3261 	 * out of space like for example punch hole, or converting
3262 	 * uninitialized extents in delalloc path. In most cases such
3263 	 * allocation would require 1, or 2 blocks, higher numbers are
3264 	 * very rare.
3265 	 */
3266 	resv_clusters = ext4_blocks_count(sbi->s_es) >> sbi->s_cluster_bits;
3267 
3268 	do_div(resv_clusters, 50);
3269 	resv_clusters = min_t(ext4_fsblk_t, resv_clusters, 4096);
3270 
3271 	return resv_clusters;
3272 }
3273 
3274 
3275 static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
3276 {
3277 	ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
3278 				sbi->s_cluster_bits;
3279 
3280 	if (count >= clusters)
3281 		return -EINVAL;
3282 
3283 	atomic64_set(&sbi->s_resv_clusters, count);
3284 	return 0;
3285 }
3286 
3287 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3288 {
3289 	char *orig_data = kstrdup(data, GFP_KERNEL);
3290 	struct buffer_head *bh;
3291 	struct ext4_super_block *es = NULL;
3292 	struct ext4_sb_info *sbi;
3293 	ext4_fsblk_t block;
3294 	ext4_fsblk_t sb_block = get_sb_block(&data);
3295 	ext4_fsblk_t logical_sb_block;
3296 	unsigned long offset = 0;
3297 	unsigned long journal_devnum = 0;
3298 	unsigned long def_mount_opts;
3299 	struct inode *root;
3300 	char *cp;
3301 	const char *descr;
3302 	int ret = -ENOMEM;
3303 	int blocksize, clustersize;
3304 	unsigned int db_count;
3305 	unsigned int i;
3306 	int needs_recovery, has_huge_files, has_bigalloc;
3307 	__u64 blocks_count;
3308 	int err = 0;
3309 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3310 	ext4_group_t first_not_zeroed;
3311 
3312 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3313 	if (!sbi)
3314 		goto out_free_orig;
3315 
3316 	sbi->s_blockgroup_lock =
3317 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3318 	if (!sbi->s_blockgroup_lock) {
3319 		kfree(sbi);
3320 		goto out_free_orig;
3321 	}
3322 	sb->s_fs_info = sbi;
3323 	sbi->s_sb = sb;
3324 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3325 	sbi->s_sb_block = sb_block;
3326 	if (sb->s_bdev->bd_part)
3327 		sbi->s_sectors_written_start =
3328 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3329 
3330 	/* Cleanup superblock name */
3331 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3332 		*cp = '!';
3333 
3334 	/* -EINVAL is default */
3335 	ret = -EINVAL;
3336 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3337 	if (!blocksize) {
3338 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3339 		goto out_fail;
3340 	}
3341 
3342 	/*
3343 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3344 	 * block sizes.  We need to calculate the offset from buffer start.
3345 	 */
3346 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3347 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3348 		offset = do_div(logical_sb_block, blocksize);
3349 	} else {
3350 		logical_sb_block = sb_block;
3351 	}
3352 
3353 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3354 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3355 		goto out_fail;
3356 	}
3357 	/*
3358 	 * Note: s_es must be initialized as soon as possible because
3359 	 *       some ext4 macro-instructions depend on its value
3360 	 */
3361 	es = (struct ext4_super_block *) (bh->b_data + offset);
3362 	sbi->s_es = es;
3363 	sb->s_magic = le16_to_cpu(es->s_magic);
3364 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3365 		goto cantfind_ext4;
3366 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3367 
3368 	/* Warn if metadata_csum and gdt_csum are both set. */
3369 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3370 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3371 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3372 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3373 			     "redundant flags; please run fsck.");
3374 
3375 	/* Check for a known checksum algorithm */
3376 	if (!ext4_verify_csum_type(sb, es)) {
3377 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3378 			 "unknown checksum algorithm.");
3379 		silent = 1;
3380 		goto cantfind_ext4;
3381 	}
3382 
3383 	/* Load the checksum driver */
3384 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3385 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3386 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3387 		if (IS_ERR(sbi->s_chksum_driver)) {
3388 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3389 			ret = PTR_ERR(sbi->s_chksum_driver);
3390 			sbi->s_chksum_driver = NULL;
3391 			goto failed_mount;
3392 		}
3393 	}
3394 
3395 	/* Check superblock checksum */
3396 	if (!ext4_superblock_csum_verify(sb, es)) {
3397 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3398 			 "invalid superblock checksum.  Run e2fsck?");
3399 		silent = 1;
3400 		goto cantfind_ext4;
3401 	}
3402 
3403 	/* Precompute checksum seed for all metadata */
3404 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3405 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3406 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3407 					       sizeof(es->s_uuid));
3408 
3409 	/* Set defaults before we parse the mount options */
3410 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3411 	set_opt(sb, INIT_INODE_TABLE);
3412 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3413 		set_opt(sb, DEBUG);
3414 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3415 		set_opt(sb, GRPID);
3416 	if (def_mount_opts & EXT4_DEFM_UID16)
3417 		set_opt(sb, NO_UID32);
3418 	/* xattr user namespace & acls are now defaulted on */
3419 	set_opt(sb, XATTR_USER);
3420 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3421 	set_opt(sb, POSIX_ACL);
3422 #endif
3423 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3424 		set_opt(sb, JOURNAL_DATA);
3425 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3426 		set_opt(sb, ORDERED_DATA);
3427 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3428 		set_opt(sb, WRITEBACK_DATA);
3429 
3430 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3431 		set_opt(sb, ERRORS_PANIC);
3432 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3433 		set_opt(sb, ERRORS_CONT);
3434 	else
3435 		set_opt(sb, ERRORS_RO);
3436 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3437 		set_opt(sb, BLOCK_VALIDITY);
3438 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3439 		set_opt(sb, DISCARD);
3440 
3441 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3442 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3443 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3444 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3445 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3446 
3447 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3448 		set_opt(sb, BARRIER);
3449 
3450 	/*
3451 	 * enable delayed allocation by default
3452 	 * Use -o nodelalloc to turn it off
3453 	 */
3454 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3455 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3456 		set_opt(sb, DELALLOC);
3457 
3458 	/*
3459 	 * set default s_li_wait_mult for lazyinit, for the case there is
3460 	 * no mount option specified.
3461 	 */
3462 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3463 
3464 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3465 			   &journal_devnum, &journal_ioprio, 0)) {
3466 		ext4_msg(sb, KERN_WARNING,
3467 			 "failed to parse options in superblock: %s",
3468 			 sbi->s_es->s_mount_opts);
3469 	}
3470 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3471 	if (!parse_options((char *) data, sb, &journal_devnum,
3472 			   &journal_ioprio, 0))
3473 		goto failed_mount;
3474 
3475 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3476 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3477 			    "with data=journal disables delayed "
3478 			    "allocation and O_DIRECT support!\n");
3479 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3480 			ext4_msg(sb, KERN_ERR, "can't mount with "
3481 				 "both data=journal and delalloc");
3482 			goto failed_mount;
3483 		}
3484 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3485 			ext4_msg(sb, KERN_ERR, "can't mount with "
3486 				 "both data=journal and dioread_nolock");
3487 			goto failed_mount;
3488 		}
3489 		if (test_opt(sb, DELALLOC))
3490 			clear_opt(sb, DELALLOC);
3491 	}
3492 
3493 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3494 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3495 
3496 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3497 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3498 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3499 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3500 		ext4_msg(sb, KERN_WARNING,
3501 		       "feature flags set on rev 0 fs, "
3502 		       "running e2fsck is recommended");
3503 
3504 	if (IS_EXT2_SB(sb)) {
3505 		if (ext2_feature_set_ok(sb))
3506 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3507 				 "using the ext4 subsystem");
3508 		else {
3509 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3510 				 "to feature incompatibilities");
3511 			goto failed_mount;
3512 		}
3513 	}
3514 
3515 	if (IS_EXT3_SB(sb)) {
3516 		if (ext3_feature_set_ok(sb))
3517 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3518 				 "using the ext4 subsystem");
3519 		else {
3520 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3521 				 "to feature incompatibilities");
3522 			goto failed_mount;
3523 		}
3524 	}
3525 
3526 	/*
3527 	 * Check feature flags regardless of the revision level, since we
3528 	 * previously didn't change the revision level when setting the flags,
3529 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3530 	 */
3531 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3532 		goto failed_mount;
3533 
3534 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3535 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3536 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3537 		ext4_msg(sb, KERN_ERR,
3538 		       "Unsupported filesystem blocksize %d", blocksize);
3539 		goto failed_mount;
3540 	}
3541 
3542 	if (sb->s_blocksize != blocksize) {
3543 		/* Validate the filesystem blocksize */
3544 		if (!sb_set_blocksize(sb, blocksize)) {
3545 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3546 					blocksize);
3547 			goto failed_mount;
3548 		}
3549 
3550 		brelse(bh);
3551 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3552 		offset = do_div(logical_sb_block, blocksize);
3553 		bh = sb_bread(sb, logical_sb_block);
3554 		if (!bh) {
3555 			ext4_msg(sb, KERN_ERR,
3556 			       "Can't read superblock on 2nd try");
3557 			goto failed_mount;
3558 		}
3559 		es = (struct ext4_super_block *)(bh->b_data + offset);
3560 		sbi->s_es = es;
3561 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3562 			ext4_msg(sb, KERN_ERR,
3563 			       "Magic mismatch, very weird!");
3564 			goto failed_mount;
3565 		}
3566 	}
3567 
3568 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3569 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3570 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3571 						      has_huge_files);
3572 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3573 
3574 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3575 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3576 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3577 	} else {
3578 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3579 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3580 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3581 		    (!is_power_of_2(sbi->s_inode_size)) ||
3582 		    (sbi->s_inode_size > blocksize)) {
3583 			ext4_msg(sb, KERN_ERR,
3584 			       "unsupported inode size: %d",
3585 			       sbi->s_inode_size);
3586 			goto failed_mount;
3587 		}
3588 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3589 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3590 	}
3591 
3592 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3593 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3594 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3595 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3596 		    !is_power_of_2(sbi->s_desc_size)) {
3597 			ext4_msg(sb, KERN_ERR,
3598 			       "unsupported descriptor size %lu",
3599 			       sbi->s_desc_size);
3600 			goto failed_mount;
3601 		}
3602 	} else
3603 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3604 
3605 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3606 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3607 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3608 		goto cantfind_ext4;
3609 
3610 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3611 	if (sbi->s_inodes_per_block == 0)
3612 		goto cantfind_ext4;
3613 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3614 					sbi->s_inodes_per_block;
3615 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3616 	sbi->s_sbh = bh;
3617 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3618 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3619 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3620 
3621 	for (i = 0; i < 4; i++)
3622 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3623 	sbi->s_def_hash_version = es->s_def_hash_version;
3624 	i = le32_to_cpu(es->s_flags);
3625 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3626 		sbi->s_hash_unsigned = 3;
3627 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3628 #ifdef __CHAR_UNSIGNED__
3629 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3630 		sbi->s_hash_unsigned = 3;
3631 #else
3632 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3633 #endif
3634 	}
3635 
3636 	/* Handle clustersize */
3637 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3638 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3639 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3640 	if (has_bigalloc) {
3641 		if (clustersize < blocksize) {
3642 			ext4_msg(sb, KERN_ERR,
3643 				 "cluster size (%d) smaller than "
3644 				 "block size (%d)", clustersize, blocksize);
3645 			goto failed_mount;
3646 		}
3647 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3648 			le32_to_cpu(es->s_log_block_size);
3649 		sbi->s_clusters_per_group =
3650 			le32_to_cpu(es->s_clusters_per_group);
3651 		if (sbi->s_clusters_per_group > blocksize * 8) {
3652 			ext4_msg(sb, KERN_ERR,
3653 				 "#clusters per group too big: %lu",
3654 				 sbi->s_clusters_per_group);
3655 			goto failed_mount;
3656 		}
3657 		if (sbi->s_blocks_per_group !=
3658 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3659 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3660 				 "clusters per group (%lu) inconsistent",
3661 				 sbi->s_blocks_per_group,
3662 				 sbi->s_clusters_per_group);
3663 			goto failed_mount;
3664 		}
3665 	} else {
3666 		if (clustersize != blocksize) {
3667 			ext4_warning(sb, "fragment/cluster size (%d) != "
3668 				     "block size (%d)", clustersize,
3669 				     blocksize);
3670 			clustersize = blocksize;
3671 		}
3672 		if (sbi->s_blocks_per_group > blocksize * 8) {
3673 			ext4_msg(sb, KERN_ERR,
3674 				 "#blocks per group too big: %lu",
3675 				 sbi->s_blocks_per_group);
3676 			goto failed_mount;
3677 		}
3678 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3679 		sbi->s_cluster_bits = 0;
3680 	}
3681 	sbi->s_cluster_ratio = clustersize / blocksize;
3682 
3683 	if (sbi->s_inodes_per_group > blocksize * 8) {
3684 		ext4_msg(sb, KERN_ERR,
3685 		       "#inodes per group too big: %lu",
3686 		       sbi->s_inodes_per_group);
3687 		goto failed_mount;
3688 	}
3689 
3690 	/* Do we have standard group size of clustersize * 8 blocks ? */
3691 	if (sbi->s_blocks_per_group == clustersize << 3)
3692 		set_opt2(sb, STD_GROUP_SIZE);
3693 
3694 	/*
3695 	 * Test whether we have more sectors than will fit in sector_t,
3696 	 * and whether the max offset is addressable by the page cache.
3697 	 */
3698 	err = generic_check_addressable(sb->s_blocksize_bits,
3699 					ext4_blocks_count(es));
3700 	if (err) {
3701 		ext4_msg(sb, KERN_ERR, "filesystem"
3702 			 " too large to mount safely on this system");
3703 		if (sizeof(sector_t) < 8)
3704 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3705 		goto failed_mount;
3706 	}
3707 
3708 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3709 		goto cantfind_ext4;
3710 
3711 	/* check blocks count against device size */
3712 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3713 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3714 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3715 		       "exceeds size of device (%llu blocks)",
3716 		       ext4_blocks_count(es), blocks_count);
3717 		goto failed_mount;
3718 	}
3719 
3720 	/*
3721 	 * It makes no sense for the first data block to be beyond the end
3722 	 * of the filesystem.
3723 	 */
3724 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3725 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3726 			 "block %u is beyond end of filesystem (%llu)",
3727 			 le32_to_cpu(es->s_first_data_block),
3728 			 ext4_blocks_count(es));
3729 		goto failed_mount;
3730 	}
3731 	blocks_count = (ext4_blocks_count(es) -
3732 			le32_to_cpu(es->s_first_data_block) +
3733 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3734 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3735 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3736 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3737 		       "(block count %llu, first data block %u, "
3738 		       "blocks per group %lu)", sbi->s_groups_count,
3739 		       ext4_blocks_count(es),
3740 		       le32_to_cpu(es->s_first_data_block),
3741 		       EXT4_BLOCKS_PER_GROUP(sb));
3742 		goto failed_mount;
3743 	}
3744 	sbi->s_groups_count = blocks_count;
3745 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3746 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3747 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3748 		   EXT4_DESC_PER_BLOCK(sb);
3749 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3750 					  sizeof(struct buffer_head *),
3751 					  GFP_KERNEL);
3752 	if (sbi->s_group_desc == NULL) {
3753 		ext4_msg(sb, KERN_ERR, "not enough memory");
3754 		ret = -ENOMEM;
3755 		goto failed_mount;
3756 	}
3757 
3758 	if (ext4_proc_root)
3759 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3760 
3761 	if (sbi->s_proc)
3762 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3763 				 &ext4_seq_options_fops, sb);
3764 
3765 	bgl_lock_init(sbi->s_blockgroup_lock);
3766 
3767 	for (i = 0; i < db_count; i++) {
3768 		block = descriptor_loc(sb, logical_sb_block, i);
3769 		sbi->s_group_desc[i] = sb_bread(sb, block);
3770 		if (!sbi->s_group_desc[i]) {
3771 			ext4_msg(sb, KERN_ERR,
3772 			       "can't read group descriptor %d", i);
3773 			db_count = i;
3774 			goto failed_mount2;
3775 		}
3776 	}
3777 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3778 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3779 		goto failed_mount2;
3780 	}
3781 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3782 		if (!ext4_fill_flex_info(sb)) {
3783 			ext4_msg(sb, KERN_ERR,
3784 			       "unable to initialize "
3785 			       "flex_bg meta info!");
3786 			goto failed_mount2;
3787 		}
3788 
3789 	sbi->s_gdb_count = db_count;
3790 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3791 	spin_lock_init(&sbi->s_next_gen_lock);
3792 
3793 	init_timer(&sbi->s_err_report);
3794 	sbi->s_err_report.function = print_daily_error_info;
3795 	sbi->s_err_report.data = (unsigned long) sb;
3796 
3797 	/* Register extent status tree shrinker */
3798 	ext4_es_register_shrinker(sbi);
3799 
3800 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3801 			ext4_count_free_clusters(sb));
3802 	if (!err) {
3803 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3804 				ext4_count_free_inodes(sb));
3805 	}
3806 	if (!err) {
3807 		err = percpu_counter_init(&sbi->s_dirs_counter,
3808 				ext4_count_dirs(sb));
3809 	}
3810 	if (!err) {
3811 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3812 	}
3813 	if (!err) {
3814 		err = percpu_counter_init(&sbi->s_extent_cache_cnt, 0);
3815 	}
3816 	if (err) {
3817 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3818 		goto failed_mount3;
3819 	}
3820 
3821 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3822 	sbi->s_extent_max_zeroout_kb = 32;
3823 
3824 	/*
3825 	 * set up enough so that it can read an inode
3826 	 */
3827 	if (!test_opt(sb, NOLOAD) &&
3828 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3829 		sb->s_op = &ext4_sops;
3830 	else
3831 		sb->s_op = &ext4_nojournal_sops;
3832 	sb->s_export_op = &ext4_export_ops;
3833 	sb->s_xattr = ext4_xattr_handlers;
3834 #ifdef CONFIG_QUOTA
3835 	sb->dq_op = &ext4_quota_operations;
3836 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
3837 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3838 	else
3839 		sb->s_qcop = &ext4_qctl_operations;
3840 #endif
3841 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3842 
3843 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3844 	mutex_init(&sbi->s_orphan_lock);
3845 
3846 	sb->s_root = NULL;
3847 
3848 	needs_recovery = (es->s_last_orphan != 0 ||
3849 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3850 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3851 
3852 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3853 	    !(sb->s_flags & MS_RDONLY))
3854 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3855 			goto failed_mount3;
3856 
3857 	/*
3858 	 * The first inode we look at is the journal inode.  Don't try
3859 	 * root first: it may be modified in the journal!
3860 	 */
3861 	if (!test_opt(sb, NOLOAD) &&
3862 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3863 		if (ext4_load_journal(sb, es, journal_devnum))
3864 			goto failed_mount3;
3865 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3866 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3867 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3868 		       "suppressed and not mounted read-only");
3869 		goto failed_mount_wq;
3870 	} else {
3871 		clear_opt(sb, DATA_FLAGS);
3872 		sbi->s_journal = NULL;
3873 		needs_recovery = 0;
3874 		goto no_journal;
3875 	}
3876 
3877 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3878 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3879 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3880 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3881 		goto failed_mount_wq;
3882 	}
3883 
3884 	if (!set_journal_csum_feature_set(sb)) {
3885 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3886 			 "feature set");
3887 		goto failed_mount_wq;
3888 	}
3889 
3890 	/* We have now updated the journal if required, so we can
3891 	 * validate the data journaling mode. */
3892 	switch (test_opt(sb, DATA_FLAGS)) {
3893 	case 0:
3894 		/* No mode set, assume a default based on the journal
3895 		 * capabilities: ORDERED_DATA if the journal can
3896 		 * cope, else JOURNAL_DATA
3897 		 */
3898 		if (jbd2_journal_check_available_features
3899 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3900 			set_opt(sb, ORDERED_DATA);
3901 		else
3902 			set_opt(sb, JOURNAL_DATA);
3903 		break;
3904 
3905 	case EXT4_MOUNT_ORDERED_DATA:
3906 	case EXT4_MOUNT_WRITEBACK_DATA:
3907 		if (!jbd2_journal_check_available_features
3908 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3909 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3910 			       "requested data journaling mode");
3911 			goto failed_mount_wq;
3912 		}
3913 	default:
3914 		break;
3915 	}
3916 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3917 
3918 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3919 
3920 	/*
3921 	 * The journal may have updated the bg summary counts, so we
3922 	 * need to update the global counters.
3923 	 */
3924 	percpu_counter_set(&sbi->s_freeclusters_counter,
3925 			   ext4_count_free_clusters(sb));
3926 	percpu_counter_set(&sbi->s_freeinodes_counter,
3927 			   ext4_count_free_inodes(sb));
3928 	percpu_counter_set(&sbi->s_dirs_counter,
3929 			   ext4_count_dirs(sb));
3930 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3931 
3932 no_journal:
3933 	/*
3934 	 * Get the # of file system overhead blocks from the
3935 	 * superblock if present.
3936 	 */
3937 	if (es->s_overhead_clusters)
3938 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3939 	else {
3940 		err = ext4_calculate_overhead(sb);
3941 		if (err)
3942 			goto failed_mount_wq;
3943 	}
3944 
3945 	/*
3946 	 * The maximum number of concurrent works can be high and
3947 	 * concurrency isn't really necessary.  Limit it to 1.
3948 	 */
3949 	EXT4_SB(sb)->rsv_conversion_wq =
3950 		alloc_workqueue("ext4-rsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3951 	if (!EXT4_SB(sb)->rsv_conversion_wq) {
3952 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3953 		ret = -ENOMEM;
3954 		goto failed_mount4;
3955 	}
3956 
3957 	EXT4_SB(sb)->unrsv_conversion_wq =
3958 		alloc_workqueue("ext4-unrsv-conversion", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3959 	if (!EXT4_SB(sb)->unrsv_conversion_wq) {
3960 		printk(KERN_ERR "EXT4-fs: failed to create workqueue\n");
3961 		ret = -ENOMEM;
3962 		goto failed_mount4;
3963 	}
3964 
3965 	/*
3966 	 * The jbd2_journal_load will have done any necessary log recovery,
3967 	 * so we can safely mount the rest of the filesystem now.
3968 	 */
3969 
3970 	root = ext4_iget(sb, EXT4_ROOT_INO);
3971 	if (IS_ERR(root)) {
3972 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3973 		ret = PTR_ERR(root);
3974 		root = NULL;
3975 		goto failed_mount4;
3976 	}
3977 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3978 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3979 		iput(root);
3980 		goto failed_mount4;
3981 	}
3982 	sb->s_root = d_make_root(root);
3983 	if (!sb->s_root) {
3984 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3985 		ret = -ENOMEM;
3986 		goto failed_mount4;
3987 	}
3988 
3989 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3990 		sb->s_flags |= MS_RDONLY;
3991 
3992 	/* determine the minimum size of new large inodes, if present */
3993 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3994 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3995 						     EXT4_GOOD_OLD_INODE_SIZE;
3996 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3997 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3998 			if (sbi->s_want_extra_isize <
3999 			    le16_to_cpu(es->s_want_extra_isize))
4000 				sbi->s_want_extra_isize =
4001 					le16_to_cpu(es->s_want_extra_isize);
4002 			if (sbi->s_want_extra_isize <
4003 			    le16_to_cpu(es->s_min_extra_isize))
4004 				sbi->s_want_extra_isize =
4005 					le16_to_cpu(es->s_min_extra_isize);
4006 		}
4007 	}
4008 	/* Check if enough inode space is available */
4009 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
4010 							sbi->s_inode_size) {
4011 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
4012 						       EXT4_GOOD_OLD_INODE_SIZE;
4013 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
4014 			 "available");
4015 	}
4016 
4017 	err = ext4_reserve_clusters(sbi, ext4_calculate_resv_clusters(sbi));
4018 	if (err) {
4019 		ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for "
4020 			 "reserved pool", ext4_calculate_resv_clusters(sbi));
4021 		goto failed_mount4a;
4022 	}
4023 
4024 	err = ext4_setup_system_zone(sb);
4025 	if (err) {
4026 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
4027 			 "zone (%d)", err);
4028 		goto failed_mount4a;
4029 	}
4030 
4031 	ext4_ext_init(sb);
4032 	err = ext4_mb_init(sb);
4033 	if (err) {
4034 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
4035 			 err);
4036 		goto failed_mount5;
4037 	}
4038 
4039 	err = ext4_register_li_request(sb, first_not_zeroed);
4040 	if (err)
4041 		goto failed_mount6;
4042 
4043 	sbi->s_kobj.kset = ext4_kset;
4044 	init_completion(&sbi->s_kobj_unregister);
4045 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
4046 				   "%s", sb->s_id);
4047 	if (err)
4048 		goto failed_mount7;
4049 
4050 #ifdef CONFIG_QUOTA
4051 	/* Enable quota usage during mount. */
4052 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4053 	    !(sb->s_flags & MS_RDONLY)) {
4054 		err = ext4_enable_quotas(sb);
4055 		if (err)
4056 			goto failed_mount8;
4057 	}
4058 #endif  /* CONFIG_QUOTA */
4059 
4060 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
4061 	ext4_orphan_cleanup(sb, es);
4062 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
4063 	if (needs_recovery) {
4064 		ext4_msg(sb, KERN_INFO, "recovery complete");
4065 		ext4_mark_recovery_complete(sb, es);
4066 	}
4067 	if (EXT4_SB(sb)->s_journal) {
4068 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4069 			descr = " journalled data mode";
4070 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4071 			descr = " ordered data mode";
4072 		else
4073 			descr = " writeback data mode";
4074 	} else
4075 		descr = "out journal";
4076 
4077 	if (test_opt(sb, DISCARD)) {
4078 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4079 		if (!blk_queue_discard(q))
4080 			ext4_msg(sb, KERN_WARNING,
4081 				 "mounting with \"discard\" option, but "
4082 				 "the device does not support discard");
4083 	}
4084 
4085 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4086 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4087 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4088 
4089 	if (es->s_error_count)
4090 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4091 
4092 	kfree(orig_data);
4093 	return 0;
4094 
4095 cantfind_ext4:
4096 	if (!silent)
4097 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4098 	goto failed_mount;
4099 
4100 #ifdef CONFIG_QUOTA
4101 failed_mount8:
4102 	kobject_del(&sbi->s_kobj);
4103 #endif
4104 failed_mount7:
4105 	ext4_unregister_li_request(sb);
4106 failed_mount6:
4107 	ext4_mb_release(sb);
4108 failed_mount5:
4109 	ext4_ext_release(sb);
4110 	ext4_release_system_zone(sb);
4111 failed_mount4a:
4112 	dput(sb->s_root);
4113 	sb->s_root = NULL;
4114 failed_mount4:
4115 	ext4_msg(sb, KERN_ERR, "mount failed");
4116 	if (EXT4_SB(sb)->rsv_conversion_wq)
4117 		destroy_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4118 	if (EXT4_SB(sb)->unrsv_conversion_wq)
4119 		destroy_workqueue(EXT4_SB(sb)->unrsv_conversion_wq);
4120 failed_mount_wq:
4121 	if (sbi->s_journal) {
4122 		jbd2_journal_destroy(sbi->s_journal);
4123 		sbi->s_journal = NULL;
4124 	}
4125 failed_mount3:
4126 	ext4_es_unregister_shrinker(sbi);
4127 	del_timer(&sbi->s_err_report);
4128 	if (sbi->s_flex_groups)
4129 		ext4_kvfree(sbi->s_flex_groups);
4130 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4131 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4132 	percpu_counter_destroy(&sbi->s_dirs_counter);
4133 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4134 	percpu_counter_destroy(&sbi->s_extent_cache_cnt);
4135 	if (sbi->s_mmp_tsk)
4136 		kthread_stop(sbi->s_mmp_tsk);
4137 failed_mount2:
4138 	for (i = 0; i < db_count; i++)
4139 		brelse(sbi->s_group_desc[i]);
4140 	ext4_kvfree(sbi->s_group_desc);
4141 failed_mount:
4142 	if (sbi->s_chksum_driver)
4143 		crypto_free_shash(sbi->s_chksum_driver);
4144 	if (sbi->s_proc) {
4145 		remove_proc_entry("options", sbi->s_proc);
4146 		remove_proc_entry(sb->s_id, ext4_proc_root);
4147 	}
4148 #ifdef CONFIG_QUOTA
4149 	for (i = 0; i < MAXQUOTAS; i++)
4150 		kfree(sbi->s_qf_names[i]);
4151 #endif
4152 	ext4_blkdev_remove(sbi);
4153 	brelse(bh);
4154 out_fail:
4155 	sb->s_fs_info = NULL;
4156 	kfree(sbi->s_blockgroup_lock);
4157 	kfree(sbi);
4158 out_free_orig:
4159 	kfree(orig_data);
4160 	return err ? err : ret;
4161 }
4162 
4163 /*
4164  * Setup any per-fs journal parameters now.  We'll do this both on
4165  * initial mount, once the journal has been initialised but before we've
4166  * done any recovery; and again on any subsequent remount.
4167  */
4168 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4169 {
4170 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4171 
4172 	journal->j_commit_interval = sbi->s_commit_interval;
4173 	journal->j_min_batch_time = sbi->s_min_batch_time;
4174 	journal->j_max_batch_time = sbi->s_max_batch_time;
4175 
4176 	write_lock(&journal->j_state_lock);
4177 	if (test_opt(sb, BARRIER))
4178 		journal->j_flags |= JBD2_BARRIER;
4179 	else
4180 		journal->j_flags &= ~JBD2_BARRIER;
4181 	if (test_opt(sb, DATA_ERR_ABORT))
4182 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4183 	else
4184 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4185 	write_unlock(&journal->j_state_lock);
4186 }
4187 
4188 static journal_t *ext4_get_journal(struct super_block *sb,
4189 				   unsigned int journal_inum)
4190 {
4191 	struct inode *journal_inode;
4192 	journal_t *journal;
4193 
4194 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4195 
4196 	/* First, test for the existence of a valid inode on disk.  Bad
4197 	 * things happen if we iget() an unused inode, as the subsequent
4198 	 * iput() will try to delete it. */
4199 
4200 	journal_inode = ext4_iget(sb, journal_inum);
4201 	if (IS_ERR(journal_inode)) {
4202 		ext4_msg(sb, KERN_ERR, "no journal found");
4203 		return NULL;
4204 	}
4205 	if (!journal_inode->i_nlink) {
4206 		make_bad_inode(journal_inode);
4207 		iput(journal_inode);
4208 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4209 		return NULL;
4210 	}
4211 
4212 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4213 		  journal_inode, journal_inode->i_size);
4214 	if (!S_ISREG(journal_inode->i_mode)) {
4215 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4216 		iput(journal_inode);
4217 		return NULL;
4218 	}
4219 
4220 	journal = jbd2_journal_init_inode(journal_inode);
4221 	if (!journal) {
4222 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4223 		iput(journal_inode);
4224 		return NULL;
4225 	}
4226 	journal->j_private = sb;
4227 	ext4_init_journal_params(sb, journal);
4228 	return journal;
4229 }
4230 
4231 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4232 				       dev_t j_dev)
4233 {
4234 	struct buffer_head *bh;
4235 	journal_t *journal;
4236 	ext4_fsblk_t start;
4237 	ext4_fsblk_t len;
4238 	int hblock, blocksize;
4239 	ext4_fsblk_t sb_block;
4240 	unsigned long offset;
4241 	struct ext4_super_block *es;
4242 	struct block_device *bdev;
4243 
4244 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4245 
4246 	bdev = ext4_blkdev_get(j_dev, sb);
4247 	if (bdev == NULL)
4248 		return NULL;
4249 
4250 	blocksize = sb->s_blocksize;
4251 	hblock = bdev_logical_block_size(bdev);
4252 	if (blocksize < hblock) {
4253 		ext4_msg(sb, KERN_ERR,
4254 			"blocksize too small for journal device");
4255 		goto out_bdev;
4256 	}
4257 
4258 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4259 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4260 	set_blocksize(bdev, blocksize);
4261 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4262 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4263 		       "external journal");
4264 		goto out_bdev;
4265 	}
4266 
4267 	es = (struct ext4_super_block *) (bh->b_data + offset);
4268 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4269 	    !(le32_to_cpu(es->s_feature_incompat) &
4270 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4271 		ext4_msg(sb, KERN_ERR, "external journal has "
4272 					"bad superblock");
4273 		brelse(bh);
4274 		goto out_bdev;
4275 	}
4276 
4277 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4278 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4279 		brelse(bh);
4280 		goto out_bdev;
4281 	}
4282 
4283 	len = ext4_blocks_count(es);
4284 	start = sb_block + 1;
4285 	brelse(bh);	/* we're done with the superblock */
4286 
4287 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4288 					start, len, blocksize);
4289 	if (!journal) {
4290 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4291 		goto out_bdev;
4292 	}
4293 	journal->j_private = sb;
4294 	ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &journal->j_sb_buffer);
4295 	wait_on_buffer(journal->j_sb_buffer);
4296 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4297 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4298 		goto out_journal;
4299 	}
4300 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4301 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4302 					"user (unsupported) - %d",
4303 			be32_to_cpu(journal->j_superblock->s_nr_users));
4304 		goto out_journal;
4305 	}
4306 	EXT4_SB(sb)->journal_bdev = bdev;
4307 	ext4_init_journal_params(sb, journal);
4308 	return journal;
4309 
4310 out_journal:
4311 	jbd2_journal_destroy(journal);
4312 out_bdev:
4313 	ext4_blkdev_put(bdev);
4314 	return NULL;
4315 }
4316 
4317 static int ext4_load_journal(struct super_block *sb,
4318 			     struct ext4_super_block *es,
4319 			     unsigned long journal_devnum)
4320 {
4321 	journal_t *journal;
4322 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4323 	dev_t journal_dev;
4324 	int err = 0;
4325 	int really_read_only;
4326 
4327 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4328 
4329 	if (journal_devnum &&
4330 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4331 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4332 			"numbers have changed");
4333 		journal_dev = new_decode_dev(journal_devnum);
4334 	} else
4335 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4336 
4337 	really_read_only = bdev_read_only(sb->s_bdev);
4338 
4339 	/*
4340 	 * Are we loading a blank journal or performing recovery after a
4341 	 * crash?  For recovery, we need to check in advance whether we
4342 	 * can get read-write access to the device.
4343 	 */
4344 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4345 		if (sb->s_flags & MS_RDONLY) {
4346 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4347 					"required on readonly filesystem");
4348 			if (really_read_only) {
4349 				ext4_msg(sb, KERN_ERR, "write access "
4350 					"unavailable, cannot proceed");
4351 				return -EROFS;
4352 			}
4353 			ext4_msg(sb, KERN_INFO, "write access will "
4354 			       "be enabled during recovery");
4355 		}
4356 	}
4357 
4358 	if (journal_inum && journal_dev) {
4359 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4360 		       "and inode journals!");
4361 		return -EINVAL;
4362 	}
4363 
4364 	if (journal_inum) {
4365 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4366 			return -EINVAL;
4367 	} else {
4368 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4369 			return -EINVAL;
4370 	}
4371 
4372 	if (!(journal->j_flags & JBD2_BARRIER))
4373 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4374 
4375 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4376 		err = jbd2_journal_wipe(journal, !really_read_only);
4377 	if (!err) {
4378 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4379 		if (save)
4380 			memcpy(save, ((char *) es) +
4381 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4382 		err = jbd2_journal_load(journal);
4383 		if (save)
4384 			memcpy(((char *) es) + EXT4_S_ERR_START,
4385 			       save, EXT4_S_ERR_LEN);
4386 		kfree(save);
4387 	}
4388 
4389 	if (err) {
4390 		ext4_msg(sb, KERN_ERR, "error loading journal");
4391 		jbd2_journal_destroy(journal);
4392 		return err;
4393 	}
4394 
4395 	EXT4_SB(sb)->s_journal = journal;
4396 	ext4_clear_journal_err(sb, es);
4397 
4398 	if (!really_read_only && journal_devnum &&
4399 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4400 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4401 
4402 		/* Make sure we flush the recovery flag to disk. */
4403 		ext4_commit_super(sb, 1);
4404 	}
4405 
4406 	return 0;
4407 }
4408 
4409 static int ext4_commit_super(struct super_block *sb, int sync)
4410 {
4411 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4412 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4413 	int error = 0;
4414 
4415 	if (!sbh || block_device_ejected(sb))
4416 		return error;
4417 	if (buffer_write_io_error(sbh)) {
4418 		/*
4419 		 * Oh, dear.  A previous attempt to write the
4420 		 * superblock failed.  This could happen because the
4421 		 * USB device was yanked out.  Or it could happen to
4422 		 * be a transient write error and maybe the block will
4423 		 * be remapped.  Nothing we can do but to retry the
4424 		 * write and hope for the best.
4425 		 */
4426 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4427 		       "superblock detected");
4428 		clear_buffer_write_io_error(sbh);
4429 		set_buffer_uptodate(sbh);
4430 	}
4431 	/*
4432 	 * If the file system is mounted read-only, don't update the
4433 	 * superblock write time.  This avoids updating the superblock
4434 	 * write time when we are mounting the root file system
4435 	 * read/only but we need to replay the journal; at that point,
4436 	 * for people who are east of GMT and who make their clock
4437 	 * tick in localtime for Windows bug-for-bug compatibility,
4438 	 * the clock is set in the future, and this will cause e2fsck
4439 	 * to complain and force a full file system check.
4440 	 */
4441 	if (!(sb->s_flags & MS_RDONLY))
4442 		es->s_wtime = cpu_to_le32(get_seconds());
4443 	if (sb->s_bdev->bd_part)
4444 		es->s_kbytes_written =
4445 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4446 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4447 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4448 	else
4449 		es->s_kbytes_written =
4450 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4451 	ext4_free_blocks_count_set(es,
4452 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4453 				&EXT4_SB(sb)->s_freeclusters_counter)));
4454 	es->s_free_inodes_count =
4455 		cpu_to_le32(percpu_counter_sum_positive(
4456 				&EXT4_SB(sb)->s_freeinodes_counter));
4457 	BUFFER_TRACE(sbh, "marking dirty");
4458 	ext4_superblock_csum_set(sb);
4459 	mark_buffer_dirty(sbh);
4460 	if (sync) {
4461 		error = sync_dirty_buffer(sbh);
4462 		if (error)
4463 			return error;
4464 
4465 		error = buffer_write_io_error(sbh);
4466 		if (error) {
4467 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4468 			       "superblock");
4469 			clear_buffer_write_io_error(sbh);
4470 			set_buffer_uptodate(sbh);
4471 		}
4472 	}
4473 	return error;
4474 }
4475 
4476 /*
4477  * Have we just finished recovery?  If so, and if we are mounting (or
4478  * remounting) the filesystem readonly, then we will end up with a
4479  * consistent fs on disk.  Record that fact.
4480  */
4481 static void ext4_mark_recovery_complete(struct super_block *sb,
4482 					struct ext4_super_block *es)
4483 {
4484 	journal_t *journal = EXT4_SB(sb)->s_journal;
4485 
4486 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4487 		BUG_ON(journal != NULL);
4488 		return;
4489 	}
4490 	jbd2_journal_lock_updates(journal);
4491 	if (jbd2_journal_flush(journal) < 0)
4492 		goto out;
4493 
4494 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4495 	    sb->s_flags & MS_RDONLY) {
4496 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4497 		ext4_commit_super(sb, 1);
4498 	}
4499 
4500 out:
4501 	jbd2_journal_unlock_updates(journal);
4502 }
4503 
4504 /*
4505  * If we are mounting (or read-write remounting) a filesystem whose journal
4506  * has recorded an error from a previous lifetime, move that error to the
4507  * main filesystem now.
4508  */
4509 static void ext4_clear_journal_err(struct super_block *sb,
4510 				   struct ext4_super_block *es)
4511 {
4512 	journal_t *journal;
4513 	int j_errno;
4514 	const char *errstr;
4515 
4516 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4517 
4518 	journal = EXT4_SB(sb)->s_journal;
4519 
4520 	/*
4521 	 * Now check for any error status which may have been recorded in the
4522 	 * journal by a prior ext4_error() or ext4_abort()
4523 	 */
4524 
4525 	j_errno = jbd2_journal_errno(journal);
4526 	if (j_errno) {
4527 		char nbuf[16];
4528 
4529 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4530 		ext4_warning(sb, "Filesystem error recorded "
4531 			     "from previous mount: %s", errstr);
4532 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4533 
4534 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4535 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4536 		ext4_commit_super(sb, 1);
4537 
4538 		jbd2_journal_clear_err(journal);
4539 		jbd2_journal_update_sb_errno(journal);
4540 	}
4541 }
4542 
4543 /*
4544  * Force the running and committing transactions to commit,
4545  * and wait on the commit.
4546  */
4547 int ext4_force_commit(struct super_block *sb)
4548 {
4549 	journal_t *journal;
4550 
4551 	if (sb->s_flags & MS_RDONLY)
4552 		return 0;
4553 
4554 	journal = EXT4_SB(sb)->s_journal;
4555 	return ext4_journal_force_commit(journal);
4556 }
4557 
4558 static int ext4_sync_fs(struct super_block *sb, int wait)
4559 {
4560 	int ret = 0;
4561 	tid_t target;
4562 	bool needs_barrier = false;
4563 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4564 
4565 	trace_ext4_sync_fs(sb, wait);
4566 	flush_workqueue(sbi->rsv_conversion_wq);
4567 	flush_workqueue(sbi->unrsv_conversion_wq);
4568 	/*
4569 	 * Writeback quota in non-journalled quota case - journalled quota has
4570 	 * no dirty dquots
4571 	 */
4572 	dquot_writeback_dquots(sb, -1);
4573 	/*
4574 	 * Data writeback is possible w/o journal transaction, so barrier must
4575 	 * being sent at the end of the function. But we can skip it if
4576 	 * transaction_commit will do it for us.
4577 	 */
4578 	target = jbd2_get_latest_transaction(sbi->s_journal);
4579 	if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&
4580 	    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))
4581 		needs_barrier = true;
4582 
4583 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4584 		if (wait)
4585 			ret = jbd2_log_wait_commit(sbi->s_journal, target);
4586 	}
4587 	if (needs_barrier) {
4588 		int err;
4589 		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4590 		if (!ret)
4591 			ret = err;
4592 	}
4593 
4594 	return ret;
4595 }
4596 
4597 static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)
4598 {
4599 	int ret = 0;
4600 
4601 	trace_ext4_sync_fs(sb, wait);
4602 	flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);
4603 	flush_workqueue(EXT4_SB(sb)->unrsv_conversion_wq);
4604 	dquot_writeback_dquots(sb, -1);
4605 	if (wait && test_opt(sb, BARRIER))
4606 		ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
4607 
4608 	return ret;
4609 }
4610 
4611 /*
4612  * LVM calls this function before a (read-only) snapshot is created.  This
4613  * gives us a chance to flush the journal completely and mark the fs clean.
4614  *
4615  * Note that only this function cannot bring a filesystem to be in a clean
4616  * state independently. It relies on upper layer to stop all data & metadata
4617  * modifications.
4618  */
4619 static int ext4_freeze(struct super_block *sb)
4620 {
4621 	int error = 0;
4622 	journal_t *journal;
4623 
4624 	if (sb->s_flags & MS_RDONLY)
4625 		return 0;
4626 
4627 	journal = EXT4_SB(sb)->s_journal;
4628 
4629 	/* Now we set up the journal barrier. */
4630 	jbd2_journal_lock_updates(journal);
4631 
4632 	/*
4633 	 * Don't clear the needs_recovery flag if we failed to flush
4634 	 * the journal.
4635 	 */
4636 	error = jbd2_journal_flush(journal);
4637 	if (error < 0)
4638 		goto out;
4639 
4640 	/* Journal blocked and flushed, clear needs_recovery flag. */
4641 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4642 	error = ext4_commit_super(sb, 1);
4643 out:
4644 	/* we rely on upper layer to stop further updates */
4645 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4646 	return error;
4647 }
4648 
4649 /*
4650  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4651  * flag here, even though the filesystem is not technically dirty yet.
4652  */
4653 static int ext4_unfreeze(struct super_block *sb)
4654 {
4655 	if (sb->s_flags & MS_RDONLY)
4656 		return 0;
4657 
4658 	/* Reset the needs_recovery flag before the fs is unlocked. */
4659 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4660 	ext4_commit_super(sb, 1);
4661 	return 0;
4662 }
4663 
4664 /*
4665  * Structure to save mount options for ext4_remount's benefit
4666  */
4667 struct ext4_mount_options {
4668 	unsigned long s_mount_opt;
4669 	unsigned long s_mount_opt2;
4670 	kuid_t s_resuid;
4671 	kgid_t s_resgid;
4672 	unsigned long s_commit_interval;
4673 	u32 s_min_batch_time, s_max_batch_time;
4674 #ifdef CONFIG_QUOTA
4675 	int s_jquota_fmt;
4676 	char *s_qf_names[MAXQUOTAS];
4677 #endif
4678 };
4679 
4680 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4681 {
4682 	struct ext4_super_block *es;
4683 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4684 	unsigned long old_sb_flags;
4685 	struct ext4_mount_options old_opts;
4686 	int enable_quota = 0;
4687 	ext4_group_t g;
4688 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4689 	int err = 0;
4690 #ifdef CONFIG_QUOTA
4691 	int i, j;
4692 #endif
4693 	char *orig_data = kstrdup(data, GFP_KERNEL);
4694 
4695 	/* Store the original options */
4696 	old_sb_flags = sb->s_flags;
4697 	old_opts.s_mount_opt = sbi->s_mount_opt;
4698 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4699 	old_opts.s_resuid = sbi->s_resuid;
4700 	old_opts.s_resgid = sbi->s_resgid;
4701 	old_opts.s_commit_interval = sbi->s_commit_interval;
4702 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4703 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4704 #ifdef CONFIG_QUOTA
4705 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4706 	for (i = 0; i < MAXQUOTAS; i++)
4707 		if (sbi->s_qf_names[i]) {
4708 			old_opts.s_qf_names[i] = kstrdup(sbi->s_qf_names[i],
4709 							 GFP_KERNEL);
4710 			if (!old_opts.s_qf_names[i]) {
4711 				for (j = 0; j < i; j++)
4712 					kfree(old_opts.s_qf_names[j]);
4713 				kfree(orig_data);
4714 				return -ENOMEM;
4715 			}
4716 		} else
4717 			old_opts.s_qf_names[i] = NULL;
4718 #endif
4719 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4720 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4721 
4722 	/*
4723 	 * Allow the "check" option to be passed as a remount option.
4724 	 */
4725 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4726 		err = -EINVAL;
4727 		goto restore_opts;
4728 	}
4729 
4730 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
4731 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
4732 			ext4_msg(sb, KERN_ERR, "can't mount with "
4733 				 "both data=journal and delalloc");
4734 			err = -EINVAL;
4735 			goto restore_opts;
4736 		}
4737 		if (test_opt(sb, DIOREAD_NOLOCK)) {
4738 			ext4_msg(sb, KERN_ERR, "can't mount with "
4739 				 "both data=journal and dioread_nolock");
4740 			err = -EINVAL;
4741 			goto restore_opts;
4742 		}
4743 	}
4744 
4745 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4746 		ext4_abort(sb, "Abort forced by user");
4747 
4748 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4749 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4750 
4751 	es = sbi->s_es;
4752 
4753 	if (sbi->s_journal) {
4754 		ext4_init_journal_params(sb, sbi->s_journal);
4755 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4756 	}
4757 
4758 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4759 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4760 			err = -EROFS;
4761 			goto restore_opts;
4762 		}
4763 
4764 		if (*flags & MS_RDONLY) {
4765 			err = dquot_suspend(sb, -1);
4766 			if (err < 0)
4767 				goto restore_opts;
4768 
4769 			/*
4770 			 * First of all, the unconditional stuff we have to do
4771 			 * to disable replay of the journal when we next remount
4772 			 */
4773 			sb->s_flags |= MS_RDONLY;
4774 
4775 			/*
4776 			 * OK, test if we are remounting a valid rw partition
4777 			 * readonly, and if so set the rdonly flag and then
4778 			 * mark the partition as valid again.
4779 			 */
4780 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4781 			    (sbi->s_mount_state & EXT4_VALID_FS))
4782 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4783 
4784 			if (sbi->s_journal)
4785 				ext4_mark_recovery_complete(sb, es);
4786 		} else {
4787 			/* Make sure we can mount this feature set readwrite */
4788 			if (!ext4_feature_set_ok(sb, 0)) {
4789 				err = -EROFS;
4790 				goto restore_opts;
4791 			}
4792 			/*
4793 			 * Make sure the group descriptor checksums
4794 			 * are sane.  If they aren't, refuse to remount r/w.
4795 			 */
4796 			for (g = 0; g < sbi->s_groups_count; g++) {
4797 				struct ext4_group_desc *gdp =
4798 					ext4_get_group_desc(sb, g, NULL);
4799 
4800 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4801 					ext4_msg(sb, KERN_ERR,
4802 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4803 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4804 					       le16_to_cpu(gdp->bg_checksum));
4805 					err = -EINVAL;
4806 					goto restore_opts;
4807 				}
4808 			}
4809 
4810 			/*
4811 			 * If we have an unprocessed orphan list hanging
4812 			 * around from a previously readonly bdev mount,
4813 			 * require a full umount/remount for now.
4814 			 */
4815 			if (es->s_last_orphan) {
4816 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4817 				       "remount RDWR because of unprocessed "
4818 				       "orphan inode list.  Please "
4819 				       "umount/remount instead");
4820 				err = -EINVAL;
4821 				goto restore_opts;
4822 			}
4823 
4824 			/*
4825 			 * Mounting a RDONLY partition read-write, so reread
4826 			 * and store the current valid flag.  (It may have
4827 			 * been changed by e2fsck since we originally mounted
4828 			 * the partition.)
4829 			 */
4830 			if (sbi->s_journal)
4831 				ext4_clear_journal_err(sb, es);
4832 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4833 			if (!ext4_setup_super(sb, es, 0))
4834 				sb->s_flags &= ~MS_RDONLY;
4835 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4836 						     EXT4_FEATURE_INCOMPAT_MMP))
4837 				if (ext4_multi_mount_protect(sb,
4838 						le64_to_cpu(es->s_mmp_block))) {
4839 					err = -EROFS;
4840 					goto restore_opts;
4841 				}
4842 			enable_quota = 1;
4843 		}
4844 	}
4845 
4846 	/*
4847 	 * Reinitialize lazy itable initialization thread based on
4848 	 * current settings
4849 	 */
4850 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4851 		ext4_unregister_li_request(sb);
4852 	else {
4853 		ext4_group_t first_not_zeroed;
4854 		first_not_zeroed = ext4_has_uninit_itable(sb);
4855 		ext4_register_li_request(sb, first_not_zeroed);
4856 	}
4857 
4858 	ext4_setup_system_zone(sb);
4859 	if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
4860 		ext4_commit_super(sb, 1);
4861 
4862 #ifdef CONFIG_QUOTA
4863 	/* Release old quota file names */
4864 	for (i = 0; i < MAXQUOTAS; i++)
4865 		kfree(old_opts.s_qf_names[i]);
4866 	if (enable_quota) {
4867 		if (sb_any_quota_suspended(sb))
4868 			dquot_resume(sb, -1);
4869 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4870 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4871 			err = ext4_enable_quotas(sb);
4872 			if (err)
4873 				goto restore_opts;
4874 		}
4875 	}
4876 #endif
4877 
4878 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4879 	kfree(orig_data);
4880 	return 0;
4881 
4882 restore_opts:
4883 	sb->s_flags = old_sb_flags;
4884 	sbi->s_mount_opt = old_opts.s_mount_opt;
4885 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4886 	sbi->s_resuid = old_opts.s_resuid;
4887 	sbi->s_resgid = old_opts.s_resgid;
4888 	sbi->s_commit_interval = old_opts.s_commit_interval;
4889 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4890 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4891 #ifdef CONFIG_QUOTA
4892 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4893 	for (i = 0; i < MAXQUOTAS; i++) {
4894 		kfree(sbi->s_qf_names[i]);
4895 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4896 	}
4897 #endif
4898 	kfree(orig_data);
4899 	return err;
4900 }
4901 
4902 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4903 {
4904 	struct super_block *sb = dentry->d_sb;
4905 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4906 	struct ext4_super_block *es = sbi->s_es;
4907 	ext4_fsblk_t overhead = 0, resv_blocks;
4908 	u64 fsid;
4909 	s64 bfree;
4910 	resv_blocks = EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
4911 
4912 	if (!test_opt(sb, MINIX_DF))
4913 		overhead = sbi->s_overhead;
4914 
4915 	buf->f_type = EXT4_SUPER_MAGIC;
4916 	buf->f_bsize = sb->s_blocksize;
4917 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4918 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4919 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4920 	/* prevent underflow in case that few free space is available */
4921 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4922 	buf->f_bavail = buf->f_bfree -
4923 			(ext4_r_blocks_count(es) + resv_blocks);
4924 	if (buf->f_bfree < (ext4_r_blocks_count(es) + resv_blocks))
4925 		buf->f_bavail = 0;
4926 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4927 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4928 	buf->f_namelen = EXT4_NAME_LEN;
4929 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4930 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4931 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4932 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4933 
4934 	return 0;
4935 }
4936 
4937 /* Helper function for writing quotas on sync - we need to start transaction
4938  * before quota file is locked for write. Otherwise the are possible deadlocks:
4939  * Process 1                         Process 2
4940  * ext4_create()                     quota_sync()
4941  *   jbd2_journal_start()                  write_dquot()
4942  *   dquot_initialize()                         down(dqio_mutex)
4943  *     down(dqio_mutex)                    jbd2_journal_start()
4944  *
4945  */
4946 
4947 #ifdef CONFIG_QUOTA
4948 
4949 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4950 {
4951 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4952 }
4953 
4954 static int ext4_write_dquot(struct dquot *dquot)
4955 {
4956 	int ret, err;
4957 	handle_t *handle;
4958 	struct inode *inode;
4959 
4960 	inode = dquot_to_inode(dquot);
4961 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4962 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4963 	if (IS_ERR(handle))
4964 		return PTR_ERR(handle);
4965 	ret = dquot_commit(dquot);
4966 	err = ext4_journal_stop(handle);
4967 	if (!ret)
4968 		ret = err;
4969 	return ret;
4970 }
4971 
4972 static int ext4_acquire_dquot(struct dquot *dquot)
4973 {
4974 	int ret, err;
4975 	handle_t *handle;
4976 
4977 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4978 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4979 	if (IS_ERR(handle))
4980 		return PTR_ERR(handle);
4981 	ret = dquot_acquire(dquot);
4982 	err = ext4_journal_stop(handle);
4983 	if (!ret)
4984 		ret = err;
4985 	return ret;
4986 }
4987 
4988 static int ext4_release_dquot(struct dquot *dquot)
4989 {
4990 	int ret, err;
4991 	handle_t *handle;
4992 
4993 	handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
4994 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4995 	if (IS_ERR(handle)) {
4996 		/* Release dquot anyway to avoid endless cycle in dqput() */
4997 		dquot_release(dquot);
4998 		return PTR_ERR(handle);
4999 	}
5000 	ret = dquot_release(dquot);
5001 	err = ext4_journal_stop(handle);
5002 	if (!ret)
5003 		ret = err;
5004 	return ret;
5005 }
5006 
5007 static int ext4_mark_dquot_dirty(struct dquot *dquot)
5008 {
5009 	struct super_block *sb = dquot->dq_sb;
5010 	struct ext4_sb_info *sbi = EXT4_SB(sb);
5011 
5012 	/* Are we journaling quotas? */
5013 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) ||
5014 	    sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
5015 		dquot_mark_dquot_dirty(dquot);
5016 		return ext4_write_dquot(dquot);
5017 	} else {
5018 		return dquot_mark_dquot_dirty(dquot);
5019 	}
5020 }
5021 
5022 static int ext4_write_info(struct super_block *sb, int type)
5023 {
5024 	int ret, err;
5025 	handle_t *handle;
5026 
5027 	/* Data block + inode block */
5028 	handle = ext4_journal_start(sb->s_root->d_inode, EXT4_HT_QUOTA, 2);
5029 	if (IS_ERR(handle))
5030 		return PTR_ERR(handle);
5031 	ret = dquot_commit_info(sb, type);
5032 	err = ext4_journal_stop(handle);
5033 	if (!ret)
5034 		ret = err;
5035 	return ret;
5036 }
5037 
5038 /*
5039  * Turn on quotas during mount time - we need to find
5040  * the quota file and such...
5041  */
5042 static int ext4_quota_on_mount(struct super_block *sb, int type)
5043 {
5044 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
5045 					EXT4_SB(sb)->s_jquota_fmt, type);
5046 }
5047 
5048 /*
5049  * Standard function to be called on quota_on
5050  */
5051 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
5052 			 struct path *path)
5053 {
5054 	int err;
5055 
5056 	if (!test_opt(sb, QUOTA))
5057 		return -EINVAL;
5058 
5059 	/* Quotafile not on the same filesystem? */
5060 	if (path->dentry->d_sb != sb)
5061 		return -EXDEV;
5062 	/* Journaling quota? */
5063 	if (EXT4_SB(sb)->s_qf_names[type]) {
5064 		/* Quotafile not in fs root? */
5065 		if (path->dentry->d_parent != sb->s_root)
5066 			ext4_msg(sb, KERN_WARNING,
5067 				"Quota file not on filesystem root. "
5068 				"Journaled quota will not work");
5069 	}
5070 
5071 	/*
5072 	 * When we journal data on quota file, we have to flush journal to see
5073 	 * all updates to the file when we bypass pagecache...
5074 	 */
5075 	if (EXT4_SB(sb)->s_journal &&
5076 	    ext4_should_journal_data(path->dentry->d_inode)) {
5077 		/*
5078 		 * We don't need to lock updates but journal_flush() could
5079 		 * otherwise be livelocked...
5080 		 */
5081 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
5082 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
5083 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
5084 		if (err)
5085 			return err;
5086 	}
5087 
5088 	return dquot_quota_on(sb, type, format_id, path);
5089 }
5090 
5091 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
5092 			     unsigned int flags)
5093 {
5094 	int err;
5095 	struct inode *qf_inode;
5096 	unsigned long qf_inums[MAXQUOTAS] = {
5097 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5098 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5099 	};
5100 
5101 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
5102 
5103 	if (!qf_inums[type])
5104 		return -EPERM;
5105 
5106 	qf_inode = ext4_iget(sb, qf_inums[type]);
5107 	if (IS_ERR(qf_inode)) {
5108 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
5109 		return PTR_ERR(qf_inode);
5110 	}
5111 
5112 	/* Don't account quota for quota files to avoid recursion */
5113 	qf_inode->i_flags |= S_NOQUOTA;
5114 	err = dquot_enable(qf_inode, type, format_id, flags);
5115 	iput(qf_inode);
5116 
5117 	return err;
5118 }
5119 
5120 /* Enable usage tracking for all quota types. */
5121 static int ext4_enable_quotas(struct super_block *sb)
5122 {
5123 	int type, err = 0;
5124 	unsigned long qf_inums[MAXQUOTAS] = {
5125 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
5126 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
5127 	};
5128 
5129 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5130 	for (type = 0; type < MAXQUOTAS; type++) {
5131 		if (qf_inums[type]) {
5132 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5133 						DQUOT_USAGE_ENABLED);
5134 			if (err) {
5135 				ext4_warning(sb,
5136 					"Failed to enable quota tracking "
5137 					"(type=%d, err=%d). Please run "
5138 					"e2fsck to fix.", type, err);
5139 				return err;
5140 			}
5141 		}
5142 	}
5143 	return 0;
5144 }
5145 
5146 /*
5147  * quota_on function that is used when QUOTA feature is set.
5148  */
5149 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5150 				 int format_id)
5151 {
5152 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5153 		return -EINVAL;
5154 
5155 	/*
5156 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
5157 	 */
5158 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5159 }
5160 
5161 static int ext4_quota_off(struct super_block *sb, int type)
5162 {
5163 	struct inode *inode = sb_dqopt(sb)->files[type];
5164 	handle_t *handle;
5165 
5166 	/* Force all delayed allocation blocks to be allocated.
5167 	 * Caller already holds s_umount sem */
5168 	if (test_opt(sb, DELALLOC))
5169 		sync_filesystem(sb);
5170 
5171 	if (!inode)
5172 		goto out;
5173 
5174 	/* Update modification times of quota files when userspace can
5175 	 * start looking at them */
5176 	handle = ext4_journal_start(inode, EXT4_HT_QUOTA, 1);
5177 	if (IS_ERR(handle))
5178 		goto out;
5179 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5180 	ext4_mark_inode_dirty(handle, inode);
5181 	ext4_journal_stop(handle);
5182 
5183 out:
5184 	return dquot_quota_off(sb, type);
5185 }
5186 
5187 /*
5188  * quota_off function that is used when QUOTA feature is set.
5189  */
5190 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5191 {
5192 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5193 		return -EINVAL;
5194 
5195 	/* Disable only the limits. */
5196 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5197 }
5198 
5199 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5200  * acquiring the locks... As quota files are never truncated and quota code
5201  * itself serializes the operations (and no one else should touch the files)
5202  * we don't have to be afraid of races */
5203 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5204 			       size_t len, loff_t off)
5205 {
5206 	struct inode *inode = sb_dqopt(sb)->files[type];
5207 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5208 	int err = 0;
5209 	int offset = off & (sb->s_blocksize - 1);
5210 	int tocopy;
5211 	size_t toread;
5212 	struct buffer_head *bh;
5213 	loff_t i_size = i_size_read(inode);
5214 
5215 	if (off > i_size)
5216 		return 0;
5217 	if (off+len > i_size)
5218 		len = i_size-off;
5219 	toread = len;
5220 	while (toread > 0) {
5221 		tocopy = sb->s_blocksize - offset < toread ?
5222 				sb->s_blocksize - offset : toread;
5223 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5224 		if (err)
5225 			return err;
5226 		if (!bh)	/* A hole? */
5227 			memset(data, 0, tocopy);
5228 		else
5229 			memcpy(data, bh->b_data+offset, tocopy);
5230 		brelse(bh);
5231 		offset = 0;
5232 		toread -= tocopy;
5233 		data += tocopy;
5234 		blk++;
5235 	}
5236 	return len;
5237 }
5238 
5239 /* Write to quotafile (we know the transaction is already started and has
5240  * enough credits) */
5241 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5242 				const char *data, size_t len, loff_t off)
5243 {
5244 	struct inode *inode = sb_dqopt(sb)->files[type];
5245 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5246 	int err = 0;
5247 	int offset = off & (sb->s_blocksize - 1);
5248 	struct buffer_head *bh;
5249 	handle_t *handle = journal_current_handle();
5250 
5251 	if (EXT4_SB(sb)->s_journal && !handle) {
5252 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5253 			" cancelled because transaction is not started",
5254 			(unsigned long long)off, (unsigned long long)len);
5255 		return -EIO;
5256 	}
5257 	/*
5258 	 * Since we account only one data block in transaction credits,
5259 	 * then it is impossible to cross a block boundary.
5260 	 */
5261 	if (sb->s_blocksize - offset < len) {
5262 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5263 			" cancelled because not block aligned",
5264 			(unsigned long long)off, (unsigned long long)len);
5265 		return -EIO;
5266 	}
5267 
5268 	bh = ext4_bread(handle, inode, blk, 1, &err);
5269 	if (!bh)
5270 		goto out;
5271 	err = ext4_journal_get_write_access(handle, bh);
5272 	if (err) {
5273 		brelse(bh);
5274 		goto out;
5275 	}
5276 	lock_buffer(bh);
5277 	memcpy(bh->b_data+offset, data, len);
5278 	flush_dcache_page(bh->b_page);
5279 	unlock_buffer(bh);
5280 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5281 	brelse(bh);
5282 out:
5283 	if (err)
5284 		return err;
5285 	if (inode->i_size < off + len) {
5286 		i_size_write(inode, off + len);
5287 		EXT4_I(inode)->i_disksize = inode->i_size;
5288 		ext4_mark_inode_dirty(handle, inode);
5289 	}
5290 	return len;
5291 }
5292 
5293 #endif
5294 
5295 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5296 		       const char *dev_name, void *data)
5297 {
5298 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5299 }
5300 
5301 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5302 static inline void register_as_ext2(void)
5303 {
5304 	int err = register_filesystem(&ext2_fs_type);
5305 	if (err)
5306 		printk(KERN_WARNING
5307 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5308 }
5309 
5310 static inline void unregister_as_ext2(void)
5311 {
5312 	unregister_filesystem(&ext2_fs_type);
5313 }
5314 
5315 static inline int ext2_feature_set_ok(struct super_block *sb)
5316 {
5317 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5318 		return 0;
5319 	if (sb->s_flags & MS_RDONLY)
5320 		return 1;
5321 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5322 		return 0;
5323 	return 1;
5324 }
5325 #else
5326 static inline void register_as_ext2(void) { }
5327 static inline void unregister_as_ext2(void) { }
5328 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5329 #endif
5330 
5331 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5332 static inline void register_as_ext3(void)
5333 {
5334 	int err = register_filesystem(&ext3_fs_type);
5335 	if (err)
5336 		printk(KERN_WARNING
5337 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5338 }
5339 
5340 static inline void unregister_as_ext3(void)
5341 {
5342 	unregister_filesystem(&ext3_fs_type);
5343 }
5344 
5345 static inline int ext3_feature_set_ok(struct super_block *sb)
5346 {
5347 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5348 		return 0;
5349 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5350 		return 0;
5351 	if (sb->s_flags & MS_RDONLY)
5352 		return 1;
5353 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5354 		return 0;
5355 	return 1;
5356 }
5357 #else
5358 static inline void register_as_ext3(void) { }
5359 static inline void unregister_as_ext3(void) { }
5360 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5361 #endif
5362 
5363 static struct file_system_type ext4_fs_type = {
5364 	.owner		= THIS_MODULE,
5365 	.name		= "ext4",
5366 	.mount		= ext4_mount,
5367 	.kill_sb	= kill_block_super,
5368 	.fs_flags	= FS_REQUIRES_DEV,
5369 };
5370 MODULE_ALIAS_FS("ext4");
5371 
5372 static int __init ext4_init_feat_adverts(void)
5373 {
5374 	struct ext4_features *ef;
5375 	int ret = -ENOMEM;
5376 
5377 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5378 	if (!ef)
5379 		goto out;
5380 
5381 	ef->f_kobj.kset = ext4_kset;
5382 	init_completion(&ef->f_kobj_unregister);
5383 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5384 				   "features");
5385 	if (ret) {
5386 		kfree(ef);
5387 		goto out;
5388 	}
5389 
5390 	ext4_feat = ef;
5391 	ret = 0;
5392 out:
5393 	return ret;
5394 }
5395 
5396 static void ext4_exit_feat_adverts(void)
5397 {
5398 	kobject_put(&ext4_feat->f_kobj);
5399 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5400 	kfree(ext4_feat);
5401 }
5402 
5403 /* Shared across all ext4 file systems */
5404 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5405 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5406 
5407 static int __init ext4_init_fs(void)
5408 {
5409 	int i, err;
5410 
5411 	ext4_li_info = NULL;
5412 	mutex_init(&ext4_li_mtx);
5413 
5414 	/* Build-time check for flags consistency */
5415 	ext4_check_flag_values();
5416 
5417 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5418 		mutex_init(&ext4__aio_mutex[i]);
5419 		init_waitqueue_head(&ext4__ioend_wq[i]);
5420 	}
5421 
5422 	err = ext4_init_es();
5423 	if (err)
5424 		return err;
5425 
5426 	err = ext4_init_pageio();
5427 	if (err)
5428 		goto out7;
5429 
5430 	err = ext4_init_system_zone();
5431 	if (err)
5432 		goto out6;
5433 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5434 	if (!ext4_kset) {
5435 		err = -ENOMEM;
5436 		goto out5;
5437 	}
5438 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5439 
5440 	err = ext4_init_feat_adverts();
5441 	if (err)
5442 		goto out4;
5443 
5444 	err = ext4_init_mballoc();
5445 	if (err)
5446 		goto out3;
5447 
5448 	err = ext4_init_xattr();
5449 	if (err)
5450 		goto out2;
5451 	err = init_inodecache();
5452 	if (err)
5453 		goto out1;
5454 	register_as_ext3();
5455 	register_as_ext2();
5456 	err = register_filesystem(&ext4_fs_type);
5457 	if (err)
5458 		goto out;
5459 
5460 	return 0;
5461 out:
5462 	unregister_as_ext2();
5463 	unregister_as_ext3();
5464 	destroy_inodecache();
5465 out1:
5466 	ext4_exit_xattr();
5467 out2:
5468 	ext4_exit_mballoc();
5469 out3:
5470 	ext4_exit_feat_adverts();
5471 out4:
5472 	if (ext4_proc_root)
5473 		remove_proc_entry("fs/ext4", NULL);
5474 	kset_unregister(ext4_kset);
5475 out5:
5476 	ext4_exit_system_zone();
5477 out6:
5478 	ext4_exit_pageio();
5479 out7:
5480 	ext4_exit_es();
5481 
5482 	return err;
5483 }
5484 
5485 static void __exit ext4_exit_fs(void)
5486 {
5487 	ext4_destroy_lazyinit_thread();
5488 	unregister_as_ext2();
5489 	unregister_as_ext3();
5490 	unregister_filesystem(&ext4_fs_type);
5491 	destroy_inodecache();
5492 	ext4_exit_xattr();
5493 	ext4_exit_mballoc();
5494 	ext4_exit_feat_adverts();
5495 	remove_proc_entry("fs/ext4", NULL);
5496 	kset_unregister(ext4_kset);
5497 	ext4_exit_system_zone();
5498 	ext4_exit_pageio();
5499 	ext4_exit_es();
5500 }
5501 
5502 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5503 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5504 MODULE_LICENSE("GPL");
5505 module_init(ext4_init_fs)
5506 module_exit(ext4_exit_fs)
5507