xref: /linux/fs/ext4/super.c (revision d97b46a64674a267bc41c9e16132ee2a98c3347d)
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"
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 const char *ext4_decode_error(struct super_block *sb, int errno,
73 				     char nbuf[16]);
74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
76 static int ext4_unfreeze(struct super_block *sb);
77 static void ext4_write_super(struct super_block *sb);
78 static int ext4_freeze(struct super_block *sb);
79 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
80 		       const char *dev_name, void *data);
81 static inline int ext2_feature_set_ok(struct super_block *sb);
82 static inline int ext3_feature_set_ok(struct super_block *sb);
83 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
84 static void ext4_destroy_lazyinit_thread(void);
85 static void ext4_unregister_li_request(struct super_block *sb);
86 static void ext4_clear_request_list(void);
87 
88 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
89 static struct file_system_type ext2_fs_type = {
90 	.owner		= THIS_MODULE,
91 	.name		= "ext2",
92 	.mount		= ext4_mount,
93 	.kill_sb	= kill_block_super,
94 	.fs_flags	= FS_REQUIRES_DEV,
95 };
96 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
97 #else
98 #define IS_EXT2_SB(sb) (0)
99 #endif
100 
101 
102 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
103 static struct file_system_type ext3_fs_type = {
104 	.owner		= THIS_MODULE,
105 	.name		= "ext3",
106 	.mount		= ext4_mount,
107 	.kill_sb	= kill_block_super,
108 	.fs_flags	= FS_REQUIRES_DEV,
109 };
110 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
111 #else
112 #define IS_EXT3_SB(sb) (0)
113 #endif
114 
115 void *ext4_kvmalloc(size_t size, gfp_t flags)
116 {
117 	void *ret;
118 
119 	ret = kmalloc(size, flags);
120 	if (!ret)
121 		ret = __vmalloc(size, flags, PAGE_KERNEL);
122 	return ret;
123 }
124 
125 void *ext4_kvzalloc(size_t size, gfp_t flags)
126 {
127 	void *ret;
128 
129 	ret = kzalloc(size, flags);
130 	if (!ret)
131 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
132 	return ret;
133 }
134 
135 void ext4_kvfree(void *ptr)
136 {
137 	if (is_vmalloc_addr(ptr))
138 		vfree(ptr);
139 	else
140 		kfree(ptr);
141 
142 }
143 
144 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
145 			       struct ext4_group_desc *bg)
146 {
147 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
148 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
149 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
150 }
151 
152 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
153 			       struct ext4_group_desc *bg)
154 {
155 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
156 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
157 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
158 }
159 
160 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
161 			      struct ext4_group_desc *bg)
162 {
163 	return le32_to_cpu(bg->bg_inode_table_lo) |
164 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
165 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
166 }
167 
168 __u32 ext4_free_group_clusters(struct super_block *sb,
169 			       struct ext4_group_desc *bg)
170 {
171 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
172 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
173 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
174 }
175 
176 __u32 ext4_free_inodes_count(struct super_block *sb,
177 			      struct ext4_group_desc *bg)
178 {
179 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
180 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
181 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
182 }
183 
184 __u32 ext4_used_dirs_count(struct super_block *sb,
185 			      struct ext4_group_desc *bg)
186 {
187 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
188 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
189 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
190 }
191 
192 __u32 ext4_itable_unused_count(struct super_block *sb,
193 			      struct ext4_group_desc *bg)
194 {
195 	return le16_to_cpu(bg->bg_itable_unused_lo) |
196 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
197 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
198 }
199 
200 void ext4_block_bitmap_set(struct super_block *sb,
201 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
202 {
203 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
204 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
205 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
206 }
207 
208 void ext4_inode_bitmap_set(struct super_block *sb,
209 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
210 {
211 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
212 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
213 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
214 }
215 
216 void ext4_inode_table_set(struct super_block *sb,
217 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
218 {
219 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
220 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
221 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
222 }
223 
224 void ext4_free_group_clusters_set(struct super_block *sb,
225 				  struct ext4_group_desc *bg, __u32 count)
226 {
227 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
228 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
229 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
230 }
231 
232 void ext4_free_inodes_set(struct super_block *sb,
233 			  struct ext4_group_desc *bg, __u32 count)
234 {
235 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
236 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
237 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
238 }
239 
240 void ext4_used_dirs_set(struct super_block *sb,
241 			  struct ext4_group_desc *bg, __u32 count)
242 {
243 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
244 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
245 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
246 }
247 
248 void ext4_itable_unused_set(struct super_block *sb,
249 			  struct ext4_group_desc *bg, __u32 count)
250 {
251 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
252 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
253 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
254 }
255 
256 
257 /* Just increment the non-pointer handle value */
258 static handle_t *ext4_get_nojournal(void)
259 {
260 	handle_t *handle = current->journal_info;
261 	unsigned long ref_cnt = (unsigned long)handle;
262 
263 	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
264 
265 	ref_cnt++;
266 	handle = (handle_t *)ref_cnt;
267 
268 	current->journal_info = handle;
269 	return handle;
270 }
271 
272 
273 /* Decrement the non-pointer handle value */
274 static void ext4_put_nojournal(handle_t *handle)
275 {
276 	unsigned long ref_cnt = (unsigned long)handle;
277 
278 	BUG_ON(ref_cnt == 0);
279 
280 	ref_cnt--;
281 	handle = (handle_t *)ref_cnt;
282 
283 	current->journal_info = handle;
284 }
285 
286 /*
287  * Wrappers for jbd2_journal_start/end.
288  *
289  * The only special thing we need to do here is to make sure that all
290  * journal_end calls result in the superblock being marked dirty, so
291  * that sync() will call the filesystem's write_super callback if
292  * appropriate.
293  *
294  * To avoid j_barrier hold in userspace when a user calls freeze(),
295  * ext4 prevents a new handle from being started by s_frozen, which
296  * is in an upper layer.
297  */
298 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
299 {
300 	journal_t *journal;
301 	handle_t  *handle;
302 
303 	trace_ext4_journal_start(sb, nblocks, _RET_IP_);
304 	if (sb->s_flags & MS_RDONLY)
305 		return ERR_PTR(-EROFS);
306 
307 	journal = EXT4_SB(sb)->s_journal;
308 	handle = ext4_journal_current_handle();
309 
310 	/*
311 	 * If a handle has been started, it should be allowed to
312 	 * finish, otherwise deadlock could happen between freeze
313 	 * and others(e.g. truncate) due to the restart of the
314 	 * journal handle if the filesystem is forzen and active
315 	 * handles are not stopped.
316 	 */
317 	if (!handle)
318 		vfs_check_frozen(sb, SB_FREEZE_TRANS);
319 
320 	if (!journal)
321 		return ext4_get_nojournal();
322 	/*
323 	 * Special case here: if the journal has aborted behind our
324 	 * backs (eg. EIO in the commit thread), then we still need to
325 	 * take the FS itself readonly cleanly.
326 	 */
327 	if (is_journal_aborted(journal)) {
328 		ext4_abort(sb, "Detected aborted journal");
329 		return ERR_PTR(-EROFS);
330 	}
331 	return jbd2_journal_start(journal, nblocks);
332 }
333 
334 /*
335  * The only special thing we need to do here is to make sure that all
336  * jbd2_journal_stop calls result in the superblock being marked dirty, so
337  * that sync() will call the filesystem's write_super callback if
338  * appropriate.
339  */
340 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
341 {
342 	struct super_block *sb;
343 	int err;
344 	int rc;
345 
346 	if (!ext4_handle_valid(handle)) {
347 		ext4_put_nojournal(handle);
348 		return 0;
349 	}
350 	sb = handle->h_transaction->t_journal->j_private;
351 	err = handle->h_err;
352 	rc = jbd2_journal_stop(handle);
353 
354 	if (!err)
355 		err = rc;
356 	if (err)
357 		__ext4_std_error(sb, where, line, err);
358 	return err;
359 }
360 
361 void ext4_journal_abort_handle(const char *caller, unsigned int line,
362 			       const char *err_fn, struct buffer_head *bh,
363 			       handle_t *handle, int err)
364 {
365 	char nbuf[16];
366 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
367 
368 	BUG_ON(!ext4_handle_valid(handle));
369 
370 	if (bh)
371 		BUFFER_TRACE(bh, "abort");
372 
373 	if (!handle->h_err)
374 		handle->h_err = err;
375 
376 	if (is_handle_aborted(handle))
377 		return;
378 
379 	printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
380 	       caller, line, errstr, err_fn);
381 
382 	jbd2_journal_abort_handle(handle);
383 }
384 
385 static void __save_error_info(struct super_block *sb, const char *func,
386 			    unsigned int line)
387 {
388 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
389 
390 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
391 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
392 	es->s_last_error_time = cpu_to_le32(get_seconds());
393 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
394 	es->s_last_error_line = cpu_to_le32(line);
395 	if (!es->s_first_error_time) {
396 		es->s_first_error_time = es->s_last_error_time;
397 		strncpy(es->s_first_error_func, func,
398 			sizeof(es->s_first_error_func));
399 		es->s_first_error_line = cpu_to_le32(line);
400 		es->s_first_error_ino = es->s_last_error_ino;
401 		es->s_first_error_block = es->s_last_error_block;
402 	}
403 	/*
404 	 * Start the daily error reporting function if it hasn't been
405 	 * started already
406 	 */
407 	if (!es->s_error_count)
408 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
409 	es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
410 }
411 
412 static void save_error_info(struct super_block *sb, const char *func,
413 			    unsigned int line)
414 {
415 	__save_error_info(sb, func, line);
416 	ext4_commit_super(sb, 1);
417 }
418 
419 /*
420  * The del_gendisk() function uninitializes the disk-specific data
421  * structures, including the bdi structure, without telling anyone
422  * else.  Once this happens, any attempt to call mark_buffer_dirty()
423  * (for example, by ext4_commit_super), will cause a kernel OOPS.
424  * This is a kludge to prevent these oops until we can put in a proper
425  * hook in del_gendisk() to inform the VFS and file system layers.
426  */
427 static int block_device_ejected(struct super_block *sb)
428 {
429 	struct inode *bd_inode = sb->s_bdev->bd_inode;
430 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
431 
432 	return bdi->dev == NULL;
433 }
434 
435 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
436 {
437 	struct super_block		*sb = journal->j_private;
438 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
439 	int				error = is_journal_aborted(journal);
440 	struct ext4_journal_cb_entry	*jce, *tmp;
441 
442 	spin_lock(&sbi->s_md_lock);
443 	list_for_each_entry_safe(jce, tmp, &txn->t_private_list, jce_list) {
444 		list_del_init(&jce->jce_list);
445 		spin_unlock(&sbi->s_md_lock);
446 		jce->jce_func(sb, jce, error);
447 		spin_lock(&sbi->s_md_lock);
448 	}
449 	spin_unlock(&sbi->s_md_lock);
450 }
451 
452 /* Deal with the reporting of failure conditions on a filesystem such as
453  * inconsistencies detected or read IO failures.
454  *
455  * On ext2, we can store the error state of the filesystem in the
456  * superblock.  That is not possible on ext4, because we may have other
457  * write ordering constraints on the superblock which prevent us from
458  * writing it out straight away; and given that the journal is about to
459  * be aborted, we can't rely on the current, or future, transactions to
460  * write out the superblock safely.
461  *
462  * We'll just use the jbd2_journal_abort() error code to record an error in
463  * the journal instead.  On recovery, the journal will complain about
464  * that error until we've noted it down and cleared it.
465  */
466 
467 static void ext4_handle_error(struct super_block *sb)
468 {
469 	if (sb->s_flags & MS_RDONLY)
470 		return;
471 
472 	if (!test_opt(sb, ERRORS_CONT)) {
473 		journal_t *journal = EXT4_SB(sb)->s_journal;
474 
475 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
476 		if (journal)
477 			jbd2_journal_abort(journal, -EIO);
478 	}
479 	if (test_opt(sb, ERRORS_RO)) {
480 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
481 		sb->s_flags |= MS_RDONLY;
482 	}
483 	if (test_opt(sb, ERRORS_PANIC))
484 		panic("EXT4-fs (device %s): panic forced after error\n",
485 			sb->s_id);
486 }
487 
488 void __ext4_error(struct super_block *sb, const char *function,
489 		  unsigned int line, const char *fmt, ...)
490 {
491 	struct va_format vaf;
492 	va_list args;
493 
494 	va_start(args, fmt);
495 	vaf.fmt = fmt;
496 	vaf.va = &args;
497 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
498 	       sb->s_id, function, line, current->comm, &vaf);
499 	va_end(args);
500 
501 	ext4_handle_error(sb);
502 }
503 
504 void ext4_error_inode(struct inode *inode, const char *function,
505 		      unsigned int line, ext4_fsblk_t block,
506 		      const char *fmt, ...)
507 {
508 	va_list args;
509 	struct va_format vaf;
510 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
511 
512 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
513 	es->s_last_error_block = cpu_to_le64(block);
514 	save_error_info(inode->i_sb, function, line);
515 	va_start(args, fmt);
516 	vaf.fmt = fmt;
517 	vaf.va = &args;
518 	if (block)
519 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
520 		       "inode #%lu: block %llu: comm %s: %pV\n",
521 		       inode->i_sb->s_id, function, line, inode->i_ino,
522 		       block, current->comm, &vaf);
523 	else
524 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
525 		       "inode #%lu: comm %s: %pV\n",
526 		       inode->i_sb->s_id, function, line, inode->i_ino,
527 		       current->comm, &vaf);
528 	va_end(args);
529 
530 	ext4_handle_error(inode->i_sb);
531 }
532 
533 void ext4_error_file(struct file *file, const char *function,
534 		     unsigned int line, ext4_fsblk_t block,
535 		     const char *fmt, ...)
536 {
537 	va_list args;
538 	struct va_format vaf;
539 	struct ext4_super_block *es;
540 	struct inode *inode = file->f_dentry->d_inode;
541 	char pathname[80], *path;
542 
543 	es = EXT4_SB(inode->i_sb)->s_es;
544 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
545 	save_error_info(inode->i_sb, function, line);
546 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
547 	if (IS_ERR(path))
548 		path = "(unknown)";
549 	va_start(args, fmt);
550 	vaf.fmt = fmt;
551 	vaf.va = &args;
552 	if (block)
553 		printk(KERN_CRIT
554 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
555 		       "block %llu: comm %s: path %s: %pV\n",
556 		       inode->i_sb->s_id, function, line, inode->i_ino,
557 		       block, current->comm, path, &vaf);
558 	else
559 		printk(KERN_CRIT
560 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
561 		       "comm %s: path %s: %pV\n",
562 		       inode->i_sb->s_id, function, line, inode->i_ino,
563 		       current->comm, path, &vaf);
564 	va_end(args);
565 
566 	ext4_handle_error(inode->i_sb);
567 }
568 
569 static const char *ext4_decode_error(struct super_block *sb, int errno,
570 				     char nbuf[16])
571 {
572 	char *errstr = NULL;
573 
574 	switch (errno) {
575 	case -EIO:
576 		errstr = "IO failure";
577 		break;
578 	case -ENOMEM:
579 		errstr = "Out of memory";
580 		break;
581 	case -EROFS:
582 		if (!sb || (EXT4_SB(sb)->s_journal &&
583 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
584 			errstr = "Journal has aborted";
585 		else
586 			errstr = "Readonly filesystem";
587 		break;
588 	default:
589 		/* If the caller passed in an extra buffer for unknown
590 		 * errors, textualise them now.  Else we just return
591 		 * NULL. */
592 		if (nbuf) {
593 			/* Check for truncated error codes... */
594 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
595 				errstr = nbuf;
596 		}
597 		break;
598 	}
599 
600 	return errstr;
601 }
602 
603 /* __ext4_std_error decodes expected errors from journaling functions
604  * automatically and invokes the appropriate error response.  */
605 
606 void __ext4_std_error(struct super_block *sb, const char *function,
607 		      unsigned int line, int errno)
608 {
609 	char nbuf[16];
610 	const char *errstr;
611 
612 	/* Special case: if the error is EROFS, and we're not already
613 	 * inside a transaction, then there's really no point in logging
614 	 * an error. */
615 	if (errno == -EROFS && journal_current_handle() == NULL &&
616 	    (sb->s_flags & MS_RDONLY))
617 		return;
618 
619 	errstr = ext4_decode_error(sb, errno, nbuf);
620 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
621 	       sb->s_id, function, line, errstr);
622 	save_error_info(sb, function, line);
623 
624 	ext4_handle_error(sb);
625 }
626 
627 /*
628  * ext4_abort is a much stronger failure handler than ext4_error.  The
629  * abort function may be used to deal with unrecoverable failures such
630  * as journal IO errors or ENOMEM at a critical moment in log management.
631  *
632  * We unconditionally force the filesystem into an ABORT|READONLY state,
633  * unless the error response on the fs has been set to panic in which
634  * case we take the easy way out and panic immediately.
635  */
636 
637 void __ext4_abort(struct super_block *sb, const char *function,
638 		unsigned int line, const char *fmt, ...)
639 {
640 	va_list args;
641 
642 	save_error_info(sb, function, line);
643 	va_start(args, fmt);
644 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
645 	       function, line);
646 	vprintk(fmt, args);
647 	printk("\n");
648 	va_end(args);
649 
650 	if ((sb->s_flags & MS_RDONLY) == 0) {
651 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
652 		sb->s_flags |= MS_RDONLY;
653 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
654 		if (EXT4_SB(sb)->s_journal)
655 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
656 		save_error_info(sb, function, line);
657 	}
658 	if (test_opt(sb, ERRORS_PANIC))
659 		panic("EXT4-fs panic from previous error\n");
660 }
661 
662 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
663 {
664 	struct va_format vaf;
665 	va_list args;
666 
667 	va_start(args, fmt);
668 	vaf.fmt = fmt;
669 	vaf.va = &args;
670 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
671 	va_end(args);
672 }
673 
674 void __ext4_warning(struct super_block *sb, const char *function,
675 		    unsigned int line, const char *fmt, ...)
676 {
677 	struct va_format vaf;
678 	va_list args;
679 
680 	va_start(args, fmt);
681 	vaf.fmt = fmt;
682 	vaf.va = &args;
683 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
684 	       sb->s_id, function, line, &vaf);
685 	va_end(args);
686 }
687 
688 void __ext4_grp_locked_error(const char *function, unsigned int line,
689 			     struct super_block *sb, ext4_group_t grp,
690 			     unsigned long ino, ext4_fsblk_t block,
691 			     const char *fmt, ...)
692 __releases(bitlock)
693 __acquires(bitlock)
694 {
695 	struct va_format vaf;
696 	va_list args;
697 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
698 
699 	es->s_last_error_ino = cpu_to_le32(ino);
700 	es->s_last_error_block = cpu_to_le64(block);
701 	__save_error_info(sb, function, line);
702 
703 	va_start(args, fmt);
704 
705 	vaf.fmt = fmt;
706 	vaf.va = &args;
707 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
708 	       sb->s_id, function, line, grp);
709 	if (ino)
710 		printk(KERN_CONT "inode %lu: ", ino);
711 	if (block)
712 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
713 	printk(KERN_CONT "%pV\n", &vaf);
714 	va_end(args);
715 
716 	if (test_opt(sb, ERRORS_CONT)) {
717 		ext4_commit_super(sb, 0);
718 		return;
719 	}
720 
721 	ext4_unlock_group(sb, grp);
722 	ext4_handle_error(sb);
723 	/*
724 	 * We only get here in the ERRORS_RO case; relocking the group
725 	 * may be dangerous, but nothing bad will happen since the
726 	 * filesystem will have already been marked read/only and the
727 	 * journal has been aborted.  We return 1 as a hint to callers
728 	 * who might what to use the return value from
729 	 * ext4_grp_locked_error() to distinguish between the
730 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
731 	 * aggressively from the ext4 function in question, with a
732 	 * more appropriate error code.
733 	 */
734 	ext4_lock_group(sb, grp);
735 	return;
736 }
737 
738 void ext4_update_dynamic_rev(struct super_block *sb)
739 {
740 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
741 
742 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
743 		return;
744 
745 	ext4_warning(sb,
746 		     "updating to rev %d because of new feature flag, "
747 		     "running e2fsck is recommended",
748 		     EXT4_DYNAMIC_REV);
749 
750 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
751 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
752 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
753 	/* leave es->s_feature_*compat flags alone */
754 	/* es->s_uuid will be set by e2fsck if empty */
755 
756 	/*
757 	 * The rest of the superblock fields should be zero, and if not it
758 	 * means they are likely already in use, so leave them alone.  We
759 	 * can leave it up to e2fsck to clean up any inconsistencies there.
760 	 */
761 }
762 
763 /*
764  * Open the external journal device
765  */
766 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
767 {
768 	struct block_device *bdev;
769 	char b[BDEVNAME_SIZE];
770 
771 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
772 	if (IS_ERR(bdev))
773 		goto fail;
774 	return bdev;
775 
776 fail:
777 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
778 			__bdevname(dev, b), PTR_ERR(bdev));
779 	return NULL;
780 }
781 
782 /*
783  * Release the journal device
784  */
785 static int ext4_blkdev_put(struct block_device *bdev)
786 {
787 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
788 }
789 
790 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
791 {
792 	struct block_device *bdev;
793 	int ret = -ENODEV;
794 
795 	bdev = sbi->journal_bdev;
796 	if (bdev) {
797 		ret = ext4_blkdev_put(bdev);
798 		sbi->journal_bdev = NULL;
799 	}
800 	return ret;
801 }
802 
803 static inline struct inode *orphan_list_entry(struct list_head *l)
804 {
805 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
806 }
807 
808 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
809 {
810 	struct list_head *l;
811 
812 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
813 		 le32_to_cpu(sbi->s_es->s_last_orphan));
814 
815 	printk(KERN_ERR "sb_info orphan list:\n");
816 	list_for_each(l, &sbi->s_orphan) {
817 		struct inode *inode = orphan_list_entry(l);
818 		printk(KERN_ERR "  "
819 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
820 		       inode->i_sb->s_id, inode->i_ino, inode,
821 		       inode->i_mode, inode->i_nlink,
822 		       NEXT_ORPHAN(inode));
823 	}
824 }
825 
826 static void ext4_put_super(struct super_block *sb)
827 {
828 	struct ext4_sb_info *sbi = EXT4_SB(sb);
829 	struct ext4_super_block *es = sbi->s_es;
830 	int i, err;
831 
832 	ext4_unregister_li_request(sb);
833 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
834 
835 	flush_workqueue(sbi->dio_unwritten_wq);
836 	destroy_workqueue(sbi->dio_unwritten_wq);
837 
838 	lock_super(sb);
839 	if (sbi->s_journal) {
840 		err = jbd2_journal_destroy(sbi->s_journal);
841 		sbi->s_journal = NULL;
842 		if (err < 0)
843 			ext4_abort(sb, "Couldn't clean up the journal");
844 	}
845 
846 	del_timer(&sbi->s_err_report);
847 	ext4_release_system_zone(sb);
848 	ext4_mb_release(sb);
849 	ext4_ext_release(sb);
850 	ext4_xattr_put_super(sb);
851 
852 	if (!(sb->s_flags & MS_RDONLY)) {
853 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
854 		es->s_state = cpu_to_le16(sbi->s_mount_state);
855 	}
856 	if (sb->s_dirt || !(sb->s_flags & MS_RDONLY))
857 		ext4_commit_super(sb, 1);
858 
859 	if (sbi->s_proc) {
860 		remove_proc_entry("options", sbi->s_proc);
861 		remove_proc_entry(sb->s_id, ext4_proc_root);
862 	}
863 	kobject_del(&sbi->s_kobj);
864 
865 	for (i = 0; i < sbi->s_gdb_count; i++)
866 		brelse(sbi->s_group_desc[i]);
867 	ext4_kvfree(sbi->s_group_desc);
868 	ext4_kvfree(sbi->s_flex_groups);
869 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
870 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
871 	percpu_counter_destroy(&sbi->s_dirs_counter);
872 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
873 	brelse(sbi->s_sbh);
874 #ifdef CONFIG_QUOTA
875 	for (i = 0; i < MAXQUOTAS; i++)
876 		kfree(sbi->s_qf_names[i]);
877 #endif
878 
879 	/* Debugging code just in case the in-memory inode orphan list
880 	 * isn't empty.  The on-disk one can be non-empty if we've
881 	 * detected an error and taken the fs readonly, but the
882 	 * in-memory list had better be clean by this point. */
883 	if (!list_empty(&sbi->s_orphan))
884 		dump_orphan_list(sb, sbi);
885 	J_ASSERT(list_empty(&sbi->s_orphan));
886 
887 	invalidate_bdev(sb->s_bdev);
888 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
889 		/*
890 		 * Invalidate the journal device's buffers.  We don't want them
891 		 * floating about in memory - the physical journal device may
892 		 * hotswapped, and it breaks the `ro-after' testing code.
893 		 */
894 		sync_blockdev(sbi->journal_bdev);
895 		invalidate_bdev(sbi->journal_bdev);
896 		ext4_blkdev_remove(sbi);
897 	}
898 	if (sbi->s_mmp_tsk)
899 		kthread_stop(sbi->s_mmp_tsk);
900 	sb->s_fs_info = NULL;
901 	/*
902 	 * Now that we are completely done shutting down the
903 	 * superblock, we need to actually destroy the kobject.
904 	 */
905 	unlock_super(sb);
906 	kobject_put(&sbi->s_kobj);
907 	wait_for_completion(&sbi->s_kobj_unregister);
908 	kfree(sbi->s_blockgroup_lock);
909 	kfree(sbi);
910 }
911 
912 static struct kmem_cache *ext4_inode_cachep;
913 
914 /*
915  * Called inside transaction, so use GFP_NOFS
916  */
917 static struct inode *ext4_alloc_inode(struct super_block *sb)
918 {
919 	struct ext4_inode_info *ei;
920 
921 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
922 	if (!ei)
923 		return NULL;
924 
925 	ei->vfs_inode.i_version = 1;
926 	ei->vfs_inode.i_data.writeback_index = 0;
927 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
928 	INIT_LIST_HEAD(&ei->i_prealloc_list);
929 	spin_lock_init(&ei->i_prealloc_lock);
930 	ei->i_reserved_data_blocks = 0;
931 	ei->i_reserved_meta_blocks = 0;
932 	ei->i_allocated_meta_blocks = 0;
933 	ei->i_da_metadata_calc_len = 0;
934 	spin_lock_init(&(ei->i_block_reservation_lock));
935 #ifdef CONFIG_QUOTA
936 	ei->i_reserved_quota = 0;
937 #endif
938 	ei->jinode = NULL;
939 	INIT_LIST_HEAD(&ei->i_completed_io_list);
940 	spin_lock_init(&ei->i_completed_io_lock);
941 	ei->cur_aio_dio = NULL;
942 	ei->i_sync_tid = 0;
943 	ei->i_datasync_tid = 0;
944 	atomic_set(&ei->i_ioend_count, 0);
945 	atomic_set(&ei->i_aiodio_unwritten, 0);
946 
947 	return &ei->vfs_inode;
948 }
949 
950 static int ext4_drop_inode(struct inode *inode)
951 {
952 	int drop = generic_drop_inode(inode);
953 
954 	trace_ext4_drop_inode(inode, drop);
955 	return drop;
956 }
957 
958 static void ext4_i_callback(struct rcu_head *head)
959 {
960 	struct inode *inode = container_of(head, struct inode, i_rcu);
961 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
962 }
963 
964 static void ext4_destroy_inode(struct inode *inode)
965 {
966 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
967 		ext4_msg(inode->i_sb, KERN_ERR,
968 			 "Inode %lu (%p): orphan list check failed!",
969 			 inode->i_ino, EXT4_I(inode));
970 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
971 				EXT4_I(inode), sizeof(struct ext4_inode_info),
972 				true);
973 		dump_stack();
974 	}
975 	call_rcu(&inode->i_rcu, ext4_i_callback);
976 }
977 
978 static void init_once(void *foo)
979 {
980 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
981 
982 	INIT_LIST_HEAD(&ei->i_orphan);
983 #ifdef CONFIG_EXT4_FS_XATTR
984 	init_rwsem(&ei->xattr_sem);
985 #endif
986 	init_rwsem(&ei->i_data_sem);
987 	inode_init_once(&ei->vfs_inode);
988 }
989 
990 static int init_inodecache(void)
991 {
992 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
993 					     sizeof(struct ext4_inode_info),
994 					     0, (SLAB_RECLAIM_ACCOUNT|
995 						SLAB_MEM_SPREAD),
996 					     init_once);
997 	if (ext4_inode_cachep == NULL)
998 		return -ENOMEM;
999 	return 0;
1000 }
1001 
1002 static void destroy_inodecache(void)
1003 {
1004 	kmem_cache_destroy(ext4_inode_cachep);
1005 }
1006 
1007 void ext4_clear_inode(struct inode *inode)
1008 {
1009 	invalidate_inode_buffers(inode);
1010 	clear_inode(inode);
1011 	dquot_drop(inode);
1012 	ext4_discard_preallocations(inode);
1013 	if (EXT4_I(inode)->jinode) {
1014 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1015 					       EXT4_I(inode)->jinode);
1016 		jbd2_free_inode(EXT4_I(inode)->jinode);
1017 		EXT4_I(inode)->jinode = NULL;
1018 	}
1019 }
1020 
1021 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1022 					u64 ino, u32 generation)
1023 {
1024 	struct inode *inode;
1025 
1026 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1027 		return ERR_PTR(-ESTALE);
1028 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1029 		return ERR_PTR(-ESTALE);
1030 
1031 	/* iget isn't really right if the inode is currently unallocated!!
1032 	 *
1033 	 * ext4_read_inode will return a bad_inode if the inode had been
1034 	 * deleted, so we should be safe.
1035 	 *
1036 	 * Currently we don't know the generation for parent directory, so
1037 	 * a generation of 0 means "accept any"
1038 	 */
1039 	inode = ext4_iget(sb, ino);
1040 	if (IS_ERR(inode))
1041 		return ERR_CAST(inode);
1042 	if (generation && inode->i_generation != generation) {
1043 		iput(inode);
1044 		return ERR_PTR(-ESTALE);
1045 	}
1046 
1047 	return inode;
1048 }
1049 
1050 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1051 					int fh_len, int fh_type)
1052 {
1053 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1054 				    ext4_nfs_get_inode);
1055 }
1056 
1057 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1058 					int fh_len, int fh_type)
1059 {
1060 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1061 				    ext4_nfs_get_inode);
1062 }
1063 
1064 /*
1065  * Try to release metadata pages (indirect blocks, directories) which are
1066  * mapped via the block device.  Since these pages could have journal heads
1067  * which would prevent try_to_free_buffers() from freeing them, we must use
1068  * jbd2 layer's try_to_free_buffers() function to release them.
1069  */
1070 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1071 				 gfp_t wait)
1072 {
1073 	journal_t *journal = EXT4_SB(sb)->s_journal;
1074 
1075 	WARN_ON(PageChecked(page));
1076 	if (!page_has_buffers(page))
1077 		return 0;
1078 	if (journal)
1079 		return jbd2_journal_try_to_free_buffers(journal, page,
1080 							wait & ~__GFP_WAIT);
1081 	return try_to_free_buffers(page);
1082 }
1083 
1084 #ifdef CONFIG_QUOTA
1085 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1086 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1087 
1088 static int ext4_write_dquot(struct dquot *dquot);
1089 static int ext4_acquire_dquot(struct dquot *dquot);
1090 static int ext4_release_dquot(struct dquot *dquot);
1091 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1092 static int ext4_write_info(struct super_block *sb, int type);
1093 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1094 			 struct path *path);
1095 static int ext4_quota_off(struct super_block *sb, int type);
1096 static int ext4_quota_on_mount(struct super_block *sb, int type);
1097 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1098 			       size_t len, loff_t off);
1099 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1100 				const char *data, size_t len, loff_t off);
1101 
1102 static const struct dquot_operations ext4_quota_operations = {
1103 	.get_reserved_space = ext4_get_reserved_space,
1104 	.write_dquot	= ext4_write_dquot,
1105 	.acquire_dquot	= ext4_acquire_dquot,
1106 	.release_dquot	= ext4_release_dquot,
1107 	.mark_dirty	= ext4_mark_dquot_dirty,
1108 	.write_info	= ext4_write_info,
1109 	.alloc_dquot	= dquot_alloc,
1110 	.destroy_dquot	= dquot_destroy,
1111 };
1112 
1113 static const struct quotactl_ops ext4_qctl_operations = {
1114 	.quota_on	= ext4_quota_on,
1115 	.quota_off	= ext4_quota_off,
1116 	.quota_sync	= dquot_quota_sync,
1117 	.get_info	= dquot_get_dqinfo,
1118 	.set_info	= dquot_set_dqinfo,
1119 	.get_dqblk	= dquot_get_dqblk,
1120 	.set_dqblk	= dquot_set_dqblk
1121 };
1122 #endif
1123 
1124 static const struct super_operations ext4_sops = {
1125 	.alloc_inode	= ext4_alloc_inode,
1126 	.destroy_inode	= ext4_destroy_inode,
1127 	.write_inode	= ext4_write_inode,
1128 	.dirty_inode	= ext4_dirty_inode,
1129 	.drop_inode	= ext4_drop_inode,
1130 	.evict_inode	= ext4_evict_inode,
1131 	.put_super	= ext4_put_super,
1132 	.sync_fs	= ext4_sync_fs,
1133 	.freeze_fs	= ext4_freeze,
1134 	.unfreeze_fs	= ext4_unfreeze,
1135 	.statfs		= ext4_statfs,
1136 	.remount_fs	= ext4_remount,
1137 	.show_options	= ext4_show_options,
1138 #ifdef CONFIG_QUOTA
1139 	.quota_read	= ext4_quota_read,
1140 	.quota_write	= ext4_quota_write,
1141 #endif
1142 	.bdev_try_to_free_page = bdev_try_to_free_page,
1143 };
1144 
1145 static const struct super_operations ext4_nojournal_sops = {
1146 	.alloc_inode	= ext4_alloc_inode,
1147 	.destroy_inode	= ext4_destroy_inode,
1148 	.write_inode	= ext4_write_inode,
1149 	.dirty_inode	= ext4_dirty_inode,
1150 	.drop_inode	= ext4_drop_inode,
1151 	.evict_inode	= ext4_evict_inode,
1152 	.write_super	= ext4_write_super,
1153 	.put_super	= ext4_put_super,
1154 	.statfs		= ext4_statfs,
1155 	.remount_fs	= ext4_remount,
1156 	.show_options	= ext4_show_options,
1157 #ifdef CONFIG_QUOTA
1158 	.quota_read	= ext4_quota_read,
1159 	.quota_write	= ext4_quota_write,
1160 #endif
1161 	.bdev_try_to_free_page = bdev_try_to_free_page,
1162 };
1163 
1164 static const struct export_operations ext4_export_ops = {
1165 	.fh_to_dentry = ext4_fh_to_dentry,
1166 	.fh_to_parent = ext4_fh_to_parent,
1167 	.get_parent = ext4_get_parent,
1168 };
1169 
1170 enum {
1171 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1172 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1173 	Opt_nouid32, Opt_debug, Opt_removed,
1174 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1175 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1176 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1177 	Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1178 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1179 	Opt_data_err_abort, Opt_data_err_ignore,
1180 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1181 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1182 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1183 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1184 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1185 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1186 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1187 	Opt_dioread_nolock, Opt_dioread_lock,
1188 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1189 };
1190 
1191 static const match_table_t tokens = {
1192 	{Opt_bsd_df, "bsddf"},
1193 	{Opt_minix_df, "minixdf"},
1194 	{Opt_grpid, "grpid"},
1195 	{Opt_grpid, "bsdgroups"},
1196 	{Opt_nogrpid, "nogrpid"},
1197 	{Opt_nogrpid, "sysvgroups"},
1198 	{Opt_resgid, "resgid=%u"},
1199 	{Opt_resuid, "resuid=%u"},
1200 	{Opt_sb, "sb=%u"},
1201 	{Opt_err_cont, "errors=continue"},
1202 	{Opt_err_panic, "errors=panic"},
1203 	{Opt_err_ro, "errors=remount-ro"},
1204 	{Opt_nouid32, "nouid32"},
1205 	{Opt_debug, "debug"},
1206 	{Opt_removed, "oldalloc"},
1207 	{Opt_removed, "orlov"},
1208 	{Opt_user_xattr, "user_xattr"},
1209 	{Opt_nouser_xattr, "nouser_xattr"},
1210 	{Opt_acl, "acl"},
1211 	{Opt_noacl, "noacl"},
1212 	{Opt_noload, "norecovery"},
1213 	{Opt_noload, "noload"},
1214 	{Opt_removed, "nobh"},
1215 	{Opt_removed, "bh"},
1216 	{Opt_commit, "commit=%u"},
1217 	{Opt_min_batch_time, "min_batch_time=%u"},
1218 	{Opt_max_batch_time, "max_batch_time=%u"},
1219 	{Opt_journal_dev, "journal_dev=%u"},
1220 	{Opt_journal_checksum, "journal_checksum"},
1221 	{Opt_journal_async_commit, "journal_async_commit"},
1222 	{Opt_abort, "abort"},
1223 	{Opt_data_journal, "data=journal"},
1224 	{Opt_data_ordered, "data=ordered"},
1225 	{Opt_data_writeback, "data=writeback"},
1226 	{Opt_data_err_abort, "data_err=abort"},
1227 	{Opt_data_err_ignore, "data_err=ignore"},
1228 	{Opt_offusrjquota, "usrjquota="},
1229 	{Opt_usrjquota, "usrjquota=%s"},
1230 	{Opt_offgrpjquota, "grpjquota="},
1231 	{Opt_grpjquota, "grpjquota=%s"},
1232 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1233 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1234 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1235 	{Opt_grpquota, "grpquota"},
1236 	{Opt_noquota, "noquota"},
1237 	{Opt_quota, "quota"},
1238 	{Opt_usrquota, "usrquota"},
1239 	{Opt_barrier, "barrier=%u"},
1240 	{Opt_barrier, "barrier"},
1241 	{Opt_nobarrier, "nobarrier"},
1242 	{Opt_i_version, "i_version"},
1243 	{Opt_stripe, "stripe=%u"},
1244 	{Opt_delalloc, "delalloc"},
1245 	{Opt_nodelalloc, "nodelalloc"},
1246 	{Opt_mblk_io_submit, "mblk_io_submit"},
1247 	{Opt_nomblk_io_submit, "nomblk_io_submit"},
1248 	{Opt_block_validity, "block_validity"},
1249 	{Opt_noblock_validity, "noblock_validity"},
1250 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1251 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1252 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1253 	{Opt_auto_da_alloc, "auto_da_alloc"},
1254 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1255 	{Opt_dioread_nolock, "dioread_nolock"},
1256 	{Opt_dioread_lock, "dioread_lock"},
1257 	{Opt_discard, "discard"},
1258 	{Opt_nodiscard, "nodiscard"},
1259 	{Opt_init_itable, "init_itable=%u"},
1260 	{Opt_init_itable, "init_itable"},
1261 	{Opt_noinit_itable, "noinit_itable"},
1262 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1263 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1264 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1265 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1266 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1267 	{Opt_err, NULL},
1268 };
1269 
1270 static ext4_fsblk_t get_sb_block(void **data)
1271 {
1272 	ext4_fsblk_t	sb_block;
1273 	char		*options = (char *) *data;
1274 
1275 	if (!options || strncmp(options, "sb=", 3) != 0)
1276 		return 1;	/* Default location */
1277 
1278 	options += 3;
1279 	/* TODO: use simple_strtoll with >32bit ext4 */
1280 	sb_block = simple_strtoul(options, &options, 0);
1281 	if (*options && *options != ',') {
1282 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1283 		       (char *) *data);
1284 		return 1;
1285 	}
1286 	if (*options == ',')
1287 		options++;
1288 	*data = (void *) options;
1289 
1290 	return sb_block;
1291 }
1292 
1293 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1294 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1295 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1296 
1297 #ifdef CONFIG_QUOTA
1298 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1299 {
1300 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1301 	char *qname;
1302 
1303 	if (sb_any_quota_loaded(sb) &&
1304 		!sbi->s_qf_names[qtype]) {
1305 		ext4_msg(sb, KERN_ERR,
1306 			"Cannot change journaled "
1307 			"quota options when quota turned on");
1308 		return -1;
1309 	}
1310 	qname = match_strdup(args);
1311 	if (!qname) {
1312 		ext4_msg(sb, KERN_ERR,
1313 			"Not enough memory for storing quotafile name");
1314 		return -1;
1315 	}
1316 	if (sbi->s_qf_names[qtype] &&
1317 		strcmp(sbi->s_qf_names[qtype], qname)) {
1318 		ext4_msg(sb, KERN_ERR,
1319 			"%s quota file already specified", QTYPE2NAME(qtype));
1320 		kfree(qname);
1321 		return -1;
1322 	}
1323 	sbi->s_qf_names[qtype] = qname;
1324 	if (strchr(sbi->s_qf_names[qtype], '/')) {
1325 		ext4_msg(sb, KERN_ERR,
1326 			"quotafile must be on filesystem root");
1327 		kfree(sbi->s_qf_names[qtype]);
1328 		sbi->s_qf_names[qtype] = NULL;
1329 		return -1;
1330 	}
1331 	set_opt(sb, QUOTA);
1332 	return 1;
1333 }
1334 
1335 static int clear_qf_name(struct super_block *sb, int qtype)
1336 {
1337 
1338 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1339 
1340 	if (sb_any_quota_loaded(sb) &&
1341 		sbi->s_qf_names[qtype]) {
1342 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1343 			" when quota turned on");
1344 		return -1;
1345 	}
1346 	/*
1347 	 * The space will be released later when all options are confirmed
1348 	 * to be correct
1349 	 */
1350 	sbi->s_qf_names[qtype] = NULL;
1351 	return 1;
1352 }
1353 #endif
1354 
1355 #define MOPT_SET	0x0001
1356 #define MOPT_CLEAR	0x0002
1357 #define MOPT_NOSUPPORT	0x0004
1358 #define MOPT_EXPLICIT	0x0008
1359 #define MOPT_CLEAR_ERR	0x0010
1360 #define MOPT_GTE0	0x0020
1361 #ifdef CONFIG_QUOTA
1362 #define MOPT_Q		0
1363 #define MOPT_QFMT	0x0040
1364 #else
1365 #define MOPT_Q		MOPT_NOSUPPORT
1366 #define MOPT_QFMT	MOPT_NOSUPPORT
1367 #endif
1368 #define MOPT_DATAJ	0x0080
1369 
1370 static const struct mount_opts {
1371 	int	token;
1372 	int	mount_opt;
1373 	int	flags;
1374 } ext4_mount_opts[] = {
1375 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1376 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1377 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1378 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1379 	{Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
1380 	{Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
1381 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1382 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1383 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
1384 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_CLEAR},
1385 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1386 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1387 	{Opt_delalloc, EXT4_MOUNT_DELALLOC, MOPT_SET | MOPT_EXPLICIT},
1388 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC, MOPT_CLEAR | MOPT_EXPLICIT},
1389 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM, MOPT_SET},
1390 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1391 				    EXT4_MOUNT_JOURNAL_CHECKSUM), MOPT_SET},
1392 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_SET},
1393 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1394 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1395 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1396 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_SET},
1397 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_CLEAR},
1398 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1399 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1400 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1401 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1402 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1403 	{Opt_commit, 0, MOPT_GTE0},
1404 	{Opt_max_batch_time, 0, MOPT_GTE0},
1405 	{Opt_min_batch_time, 0, MOPT_GTE0},
1406 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1407 	{Opt_init_itable, 0, MOPT_GTE0},
1408 	{Opt_stripe, 0, MOPT_GTE0},
1409 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
1410 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
1411 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
1412 #ifdef CONFIG_EXT4_FS_XATTR
1413 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1414 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1415 #else
1416 	{Opt_user_xattr, 0, MOPT_NOSUPPORT},
1417 	{Opt_nouser_xattr, 0, MOPT_NOSUPPORT},
1418 #endif
1419 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1420 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1421 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1422 #else
1423 	{Opt_acl, 0, MOPT_NOSUPPORT},
1424 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1425 #endif
1426 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1427 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1428 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1429 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1430 							MOPT_SET | MOPT_Q},
1431 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1432 							MOPT_SET | MOPT_Q},
1433 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1434 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1435 	{Opt_usrjquota, 0, MOPT_Q},
1436 	{Opt_grpjquota, 0, MOPT_Q},
1437 	{Opt_offusrjquota, 0, MOPT_Q},
1438 	{Opt_offgrpjquota, 0, MOPT_Q},
1439 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1440 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1441 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1442 	{Opt_err, 0, 0}
1443 };
1444 
1445 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1446 			    substring_t *args, unsigned long *journal_devnum,
1447 			    unsigned int *journal_ioprio, int is_remount)
1448 {
1449 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1450 	const struct mount_opts *m;
1451 	kuid_t uid;
1452 	kgid_t gid;
1453 	int arg = 0;
1454 
1455 #ifdef CONFIG_QUOTA
1456 	if (token == Opt_usrjquota)
1457 		return set_qf_name(sb, USRQUOTA, &args[0]);
1458 	else if (token == Opt_grpjquota)
1459 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1460 	else if (token == Opt_offusrjquota)
1461 		return clear_qf_name(sb, USRQUOTA);
1462 	else if (token == Opt_offgrpjquota)
1463 		return clear_qf_name(sb, GRPQUOTA);
1464 #endif
1465 	if (args->from && match_int(args, &arg))
1466 		return -1;
1467 	switch (token) {
1468 	case Opt_noacl:
1469 	case Opt_nouser_xattr:
1470 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1471 		break;
1472 	case Opt_sb:
1473 		return 1;	/* handled by get_sb_block() */
1474 	case Opt_removed:
1475 		ext4_msg(sb, KERN_WARNING,
1476 			 "Ignoring removed %s option", opt);
1477 		return 1;
1478 	case Opt_resuid:
1479 		uid = make_kuid(current_user_ns(), arg);
1480 		if (!uid_valid(uid)) {
1481 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1482 			return -1;
1483 		}
1484 		sbi->s_resuid = uid;
1485 		return 1;
1486 	case Opt_resgid:
1487 		gid = make_kgid(current_user_ns(), arg);
1488 		if (!gid_valid(gid)) {
1489 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1490 			return -1;
1491 		}
1492 		sbi->s_resgid = gid;
1493 		return 1;
1494 	case Opt_abort:
1495 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1496 		return 1;
1497 	case Opt_i_version:
1498 		sb->s_flags |= MS_I_VERSION;
1499 		return 1;
1500 	case Opt_journal_dev:
1501 		if (is_remount) {
1502 			ext4_msg(sb, KERN_ERR,
1503 				 "Cannot specify journal on remount");
1504 			return -1;
1505 		}
1506 		*journal_devnum = arg;
1507 		return 1;
1508 	case Opt_journal_ioprio:
1509 		if (arg < 0 || arg > 7)
1510 			return -1;
1511 		*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1512 		return 1;
1513 	}
1514 
1515 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1516 		if (token != m->token)
1517 			continue;
1518 		if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1519 			return -1;
1520 		if (m->flags & MOPT_EXPLICIT)
1521 			set_opt2(sb, EXPLICIT_DELALLOC);
1522 		if (m->flags & MOPT_CLEAR_ERR)
1523 			clear_opt(sb, ERRORS_MASK);
1524 		if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1525 			ext4_msg(sb, KERN_ERR, "Cannot change quota "
1526 				 "options when quota turned on");
1527 			return -1;
1528 		}
1529 
1530 		if (m->flags & MOPT_NOSUPPORT) {
1531 			ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1532 		} else if (token == Opt_commit) {
1533 			if (arg == 0)
1534 				arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1535 			sbi->s_commit_interval = HZ * arg;
1536 		} else if (token == Opt_max_batch_time) {
1537 			if (arg == 0)
1538 				arg = EXT4_DEF_MAX_BATCH_TIME;
1539 			sbi->s_max_batch_time = arg;
1540 		} else if (token == Opt_min_batch_time) {
1541 			sbi->s_min_batch_time = arg;
1542 		} else if (token == Opt_inode_readahead_blks) {
1543 			if (arg > (1 << 30))
1544 				return -1;
1545 			if (arg && !is_power_of_2(arg)) {
1546 				ext4_msg(sb, KERN_ERR,
1547 					 "EXT4-fs: inode_readahead_blks"
1548 					 " must be a power of 2");
1549 				return -1;
1550 			}
1551 			sbi->s_inode_readahead_blks = arg;
1552 		} else if (token == Opt_init_itable) {
1553 			set_opt(sb, INIT_INODE_TABLE);
1554 			if (!args->from)
1555 				arg = EXT4_DEF_LI_WAIT_MULT;
1556 			sbi->s_li_wait_mult = arg;
1557 		} else if (token == Opt_stripe) {
1558 			sbi->s_stripe = arg;
1559 		} else if (m->flags & MOPT_DATAJ) {
1560 			if (is_remount) {
1561 				if (!sbi->s_journal)
1562 					ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1563 				else if (test_opt(sb, DATA_FLAGS) !=
1564 					 m->mount_opt) {
1565 					ext4_msg(sb, KERN_ERR,
1566 					 "Cannot change data mode on remount");
1567 					return -1;
1568 				}
1569 			} else {
1570 				clear_opt(sb, DATA_FLAGS);
1571 				sbi->s_mount_opt |= m->mount_opt;
1572 			}
1573 #ifdef CONFIG_QUOTA
1574 		} else if (m->flags & MOPT_QFMT) {
1575 			if (sb_any_quota_loaded(sb) &&
1576 			    sbi->s_jquota_fmt != m->mount_opt) {
1577 				ext4_msg(sb, KERN_ERR, "Cannot "
1578 					 "change journaled quota options "
1579 					 "when quota turned on");
1580 				return -1;
1581 			}
1582 			sbi->s_jquota_fmt = m->mount_opt;
1583 #endif
1584 		} else {
1585 			if (!args->from)
1586 				arg = 1;
1587 			if (m->flags & MOPT_CLEAR)
1588 				arg = !arg;
1589 			else if (unlikely(!(m->flags & MOPT_SET))) {
1590 				ext4_msg(sb, KERN_WARNING,
1591 					 "buggy handling of option %s", opt);
1592 				WARN_ON(1);
1593 				return -1;
1594 			}
1595 			if (arg != 0)
1596 				sbi->s_mount_opt |= m->mount_opt;
1597 			else
1598 				sbi->s_mount_opt &= ~m->mount_opt;
1599 		}
1600 		return 1;
1601 	}
1602 	ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1603 		 "or missing value", opt);
1604 	return -1;
1605 }
1606 
1607 static int parse_options(char *options, struct super_block *sb,
1608 			 unsigned long *journal_devnum,
1609 			 unsigned int *journal_ioprio,
1610 			 int is_remount)
1611 {
1612 #ifdef CONFIG_QUOTA
1613 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1614 #endif
1615 	char *p;
1616 	substring_t args[MAX_OPT_ARGS];
1617 	int token;
1618 
1619 	if (!options)
1620 		return 1;
1621 
1622 	while ((p = strsep(&options, ",")) != NULL) {
1623 		if (!*p)
1624 			continue;
1625 		/*
1626 		 * Initialize args struct so we know whether arg was
1627 		 * found; some options take optional arguments.
1628 		 */
1629 		args[0].to = args[0].from = 0;
1630 		token = match_token(p, tokens, args);
1631 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1632 				     journal_ioprio, is_remount) < 0)
1633 			return 0;
1634 	}
1635 #ifdef CONFIG_QUOTA
1636 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1637 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1638 			clear_opt(sb, USRQUOTA);
1639 
1640 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1641 			clear_opt(sb, GRPQUOTA);
1642 
1643 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1644 			ext4_msg(sb, KERN_ERR, "old and new quota "
1645 					"format mixing");
1646 			return 0;
1647 		}
1648 
1649 		if (!sbi->s_jquota_fmt) {
1650 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1651 					"not specified");
1652 			return 0;
1653 		}
1654 	} else {
1655 		if (sbi->s_jquota_fmt) {
1656 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1657 					"specified with no journaling "
1658 					"enabled");
1659 			return 0;
1660 		}
1661 	}
1662 #endif
1663 	return 1;
1664 }
1665 
1666 static inline void ext4_show_quota_options(struct seq_file *seq,
1667 					   struct super_block *sb)
1668 {
1669 #if defined(CONFIG_QUOTA)
1670 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1671 
1672 	if (sbi->s_jquota_fmt) {
1673 		char *fmtname = "";
1674 
1675 		switch (sbi->s_jquota_fmt) {
1676 		case QFMT_VFS_OLD:
1677 			fmtname = "vfsold";
1678 			break;
1679 		case QFMT_VFS_V0:
1680 			fmtname = "vfsv0";
1681 			break;
1682 		case QFMT_VFS_V1:
1683 			fmtname = "vfsv1";
1684 			break;
1685 		}
1686 		seq_printf(seq, ",jqfmt=%s", fmtname);
1687 	}
1688 
1689 	if (sbi->s_qf_names[USRQUOTA])
1690 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1691 
1692 	if (sbi->s_qf_names[GRPQUOTA])
1693 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1694 
1695 	if (test_opt(sb, USRQUOTA))
1696 		seq_puts(seq, ",usrquota");
1697 
1698 	if (test_opt(sb, GRPQUOTA))
1699 		seq_puts(seq, ",grpquota");
1700 #endif
1701 }
1702 
1703 static const char *token2str(int token)
1704 {
1705 	static const struct match_token *t;
1706 
1707 	for (t = tokens; t->token != Opt_err; t++)
1708 		if (t->token == token && !strchr(t->pattern, '='))
1709 			break;
1710 	return t->pattern;
1711 }
1712 
1713 /*
1714  * Show an option if
1715  *  - it's set to a non-default value OR
1716  *  - if the per-sb default is different from the global default
1717  */
1718 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1719 			      int nodefs)
1720 {
1721 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1722 	struct ext4_super_block *es = sbi->s_es;
1723 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1724 	const struct mount_opts *m;
1725 	char sep = nodefs ? '\n' : ',';
1726 
1727 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1728 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1729 
1730 	if (sbi->s_sb_block != 1)
1731 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1732 
1733 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1734 		int want_set = m->flags & MOPT_SET;
1735 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1736 		    (m->flags & MOPT_CLEAR_ERR))
1737 			continue;
1738 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1739 			continue; /* skip if same as the default */
1740 		if ((want_set &&
1741 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1742 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1743 			continue; /* select Opt_noFoo vs Opt_Foo */
1744 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1745 	}
1746 
1747 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1748 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1749 		SEQ_OPTS_PRINT("resuid=%u",
1750 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1751 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1752 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1753 		SEQ_OPTS_PRINT("resgid=%u",
1754 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1755 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1756 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1757 		SEQ_OPTS_PUTS("errors=remount-ro");
1758 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1759 		SEQ_OPTS_PUTS("errors=continue");
1760 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1761 		SEQ_OPTS_PUTS("errors=panic");
1762 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1763 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1764 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1765 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1766 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1767 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1768 	if (sb->s_flags & MS_I_VERSION)
1769 		SEQ_OPTS_PUTS("i_version");
1770 	if (nodefs || sbi->s_stripe)
1771 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1772 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1773 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1774 			SEQ_OPTS_PUTS("data=journal");
1775 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1776 			SEQ_OPTS_PUTS("data=ordered");
1777 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1778 			SEQ_OPTS_PUTS("data=writeback");
1779 	}
1780 	if (nodefs ||
1781 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1782 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1783 			       sbi->s_inode_readahead_blks);
1784 
1785 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1786 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1787 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1788 
1789 	ext4_show_quota_options(seq, sb);
1790 	return 0;
1791 }
1792 
1793 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1794 {
1795 	return _ext4_show_options(seq, root->d_sb, 0);
1796 }
1797 
1798 static int options_seq_show(struct seq_file *seq, void *offset)
1799 {
1800 	struct super_block *sb = seq->private;
1801 	int rc;
1802 
1803 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1804 	rc = _ext4_show_options(seq, sb, 1);
1805 	seq_puts(seq, "\n");
1806 	return rc;
1807 }
1808 
1809 static int options_open_fs(struct inode *inode, struct file *file)
1810 {
1811 	return single_open(file, options_seq_show, PDE(inode)->data);
1812 }
1813 
1814 static const struct file_operations ext4_seq_options_fops = {
1815 	.owner = THIS_MODULE,
1816 	.open = options_open_fs,
1817 	.read = seq_read,
1818 	.llseek = seq_lseek,
1819 	.release = single_release,
1820 };
1821 
1822 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1823 			    int read_only)
1824 {
1825 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1826 	int res = 0;
1827 
1828 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1829 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1830 			 "forcing read-only mode");
1831 		res = MS_RDONLY;
1832 	}
1833 	if (read_only)
1834 		goto done;
1835 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1836 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1837 			 "running e2fsck is recommended");
1838 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1839 		ext4_msg(sb, KERN_WARNING,
1840 			 "warning: mounting fs with errors, "
1841 			 "running e2fsck is recommended");
1842 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1843 		 le16_to_cpu(es->s_mnt_count) >=
1844 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1845 		ext4_msg(sb, KERN_WARNING,
1846 			 "warning: maximal mount count reached, "
1847 			 "running e2fsck is recommended");
1848 	else if (le32_to_cpu(es->s_checkinterval) &&
1849 		(le32_to_cpu(es->s_lastcheck) +
1850 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1851 		ext4_msg(sb, KERN_WARNING,
1852 			 "warning: checktime reached, "
1853 			 "running e2fsck is recommended");
1854 	if (!sbi->s_journal)
1855 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1856 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1857 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1858 	le16_add_cpu(&es->s_mnt_count, 1);
1859 	es->s_mtime = cpu_to_le32(get_seconds());
1860 	ext4_update_dynamic_rev(sb);
1861 	if (sbi->s_journal)
1862 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1863 
1864 	ext4_commit_super(sb, 1);
1865 done:
1866 	if (test_opt(sb, DEBUG))
1867 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1868 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1869 			sb->s_blocksize,
1870 			sbi->s_groups_count,
1871 			EXT4_BLOCKS_PER_GROUP(sb),
1872 			EXT4_INODES_PER_GROUP(sb),
1873 			sbi->s_mount_opt, sbi->s_mount_opt2);
1874 
1875 	cleancache_init_fs(sb);
1876 	return res;
1877 }
1878 
1879 static int ext4_fill_flex_info(struct super_block *sb)
1880 {
1881 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1882 	struct ext4_group_desc *gdp = NULL;
1883 	ext4_group_t flex_group_count;
1884 	ext4_group_t flex_group;
1885 	unsigned int groups_per_flex = 0;
1886 	size_t size;
1887 	int i;
1888 
1889 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1890 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1891 		sbi->s_log_groups_per_flex = 0;
1892 		return 1;
1893 	}
1894 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1895 
1896 	/* We allocate both existing and potentially added groups */
1897 	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1898 			((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1899 			      EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1900 	size = flex_group_count * sizeof(struct flex_groups);
1901 	sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
1902 	if (sbi->s_flex_groups == NULL) {
1903 		ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
1904 			 flex_group_count);
1905 		goto failed;
1906 	}
1907 
1908 	for (i = 0; i < sbi->s_groups_count; i++) {
1909 		gdp = ext4_get_group_desc(sb, i, NULL);
1910 
1911 		flex_group = ext4_flex_group(sbi, i);
1912 		atomic_add(ext4_free_inodes_count(sb, gdp),
1913 			   &sbi->s_flex_groups[flex_group].free_inodes);
1914 		atomic_add(ext4_free_group_clusters(sb, gdp),
1915 			   &sbi->s_flex_groups[flex_group].free_clusters);
1916 		atomic_add(ext4_used_dirs_count(sb, gdp),
1917 			   &sbi->s_flex_groups[flex_group].used_dirs);
1918 	}
1919 
1920 	return 1;
1921 failed:
1922 	return 0;
1923 }
1924 
1925 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1926 			    struct ext4_group_desc *gdp)
1927 {
1928 	__u16 crc = 0;
1929 
1930 	if (sbi->s_es->s_feature_ro_compat &
1931 	    cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1932 		int offset = offsetof(struct ext4_group_desc, bg_checksum);
1933 		__le32 le_group = cpu_to_le32(block_group);
1934 
1935 		crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1936 		crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1937 		crc = crc16(crc, (__u8 *)gdp, offset);
1938 		offset += sizeof(gdp->bg_checksum); /* skip checksum */
1939 		/* for checksum of struct ext4_group_desc do the rest...*/
1940 		if ((sbi->s_es->s_feature_incompat &
1941 		     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1942 		    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1943 			crc = crc16(crc, (__u8 *)gdp + offset,
1944 				    le16_to_cpu(sbi->s_es->s_desc_size) -
1945 					offset);
1946 	}
1947 
1948 	return cpu_to_le16(crc);
1949 }
1950 
1951 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1952 				struct ext4_group_desc *gdp)
1953 {
1954 	if ((sbi->s_es->s_feature_ro_compat &
1955 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1956 	    (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1957 		return 0;
1958 
1959 	return 1;
1960 }
1961 
1962 /* Called at mount-time, super-block is locked */
1963 static int ext4_check_descriptors(struct super_block *sb,
1964 				  ext4_group_t *first_not_zeroed)
1965 {
1966 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1967 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1968 	ext4_fsblk_t last_block;
1969 	ext4_fsblk_t block_bitmap;
1970 	ext4_fsblk_t inode_bitmap;
1971 	ext4_fsblk_t inode_table;
1972 	int flexbg_flag = 0;
1973 	ext4_group_t i, grp = sbi->s_groups_count;
1974 
1975 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1976 		flexbg_flag = 1;
1977 
1978 	ext4_debug("Checking group descriptors");
1979 
1980 	for (i = 0; i < sbi->s_groups_count; i++) {
1981 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1982 
1983 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
1984 			last_block = ext4_blocks_count(sbi->s_es) - 1;
1985 		else
1986 			last_block = first_block +
1987 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
1988 
1989 		if ((grp == sbi->s_groups_count) &&
1990 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
1991 			grp = i;
1992 
1993 		block_bitmap = ext4_block_bitmap(sb, gdp);
1994 		if (block_bitmap < first_block || block_bitmap > last_block) {
1995 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1996 			       "Block bitmap for group %u not in group "
1997 			       "(block %llu)!", i, block_bitmap);
1998 			return 0;
1999 		}
2000 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2001 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2002 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2003 			       "Inode bitmap for group %u not in group "
2004 			       "(block %llu)!", i, inode_bitmap);
2005 			return 0;
2006 		}
2007 		inode_table = ext4_inode_table(sb, gdp);
2008 		if (inode_table < first_block ||
2009 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2010 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2011 			       "Inode table for group %u not in group "
2012 			       "(block %llu)!", i, inode_table);
2013 			return 0;
2014 		}
2015 		ext4_lock_group(sb, i);
2016 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2017 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2018 				 "Checksum for group %u failed (%u!=%u)",
2019 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2020 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2021 			if (!(sb->s_flags & MS_RDONLY)) {
2022 				ext4_unlock_group(sb, i);
2023 				return 0;
2024 			}
2025 		}
2026 		ext4_unlock_group(sb, i);
2027 		if (!flexbg_flag)
2028 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2029 	}
2030 	if (NULL != first_not_zeroed)
2031 		*first_not_zeroed = grp;
2032 
2033 	ext4_free_blocks_count_set(sbi->s_es,
2034 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2035 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2036 	return 1;
2037 }
2038 
2039 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2040  * the superblock) which were deleted from all directories, but held open by
2041  * a process at the time of a crash.  We walk the list and try to delete these
2042  * inodes at recovery time (only with a read-write filesystem).
2043  *
2044  * In order to keep the orphan inode chain consistent during traversal (in
2045  * case of crash during recovery), we link each inode into the superblock
2046  * orphan list_head and handle it the same way as an inode deletion during
2047  * normal operation (which journals the operations for us).
2048  *
2049  * We only do an iget() and an iput() on each inode, which is very safe if we
2050  * accidentally point at an in-use or already deleted inode.  The worst that
2051  * can happen in this case is that we get a "bit already cleared" message from
2052  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2053  * e2fsck was run on this filesystem, and it must have already done the orphan
2054  * inode cleanup for us, so we can safely abort without any further action.
2055  */
2056 static void ext4_orphan_cleanup(struct super_block *sb,
2057 				struct ext4_super_block *es)
2058 {
2059 	unsigned int s_flags = sb->s_flags;
2060 	int nr_orphans = 0, nr_truncates = 0;
2061 #ifdef CONFIG_QUOTA
2062 	int i;
2063 #endif
2064 	if (!es->s_last_orphan) {
2065 		jbd_debug(4, "no orphan inodes to clean up\n");
2066 		return;
2067 	}
2068 
2069 	if (bdev_read_only(sb->s_bdev)) {
2070 		ext4_msg(sb, KERN_ERR, "write access "
2071 			"unavailable, skipping orphan cleanup");
2072 		return;
2073 	}
2074 
2075 	/* Check if feature set would not allow a r/w mount */
2076 	if (!ext4_feature_set_ok(sb, 0)) {
2077 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2078 			 "unknown ROCOMPAT features");
2079 		return;
2080 	}
2081 
2082 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2083 		if (es->s_last_orphan)
2084 			jbd_debug(1, "Errors on filesystem, "
2085 				  "clearing orphan list.\n");
2086 		es->s_last_orphan = 0;
2087 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2088 		return;
2089 	}
2090 
2091 	if (s_flags & MS_RDONLY) {
2092 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2093 		sb->s_flags &= ~MS_RDONLY;
2094 	}
2095 #ifdef CONFIG_QUOTA
2096 	/* Needed for iput() to work correctly and not trash data */
2097 	sb->s_flags |= MS_ACTIVE;
2098 	/* Turn on quotas so that they are updated correctly */
2099 	for (i = 0; i < MAXQUOTAS; i++) {
2100 		if (EXT4_SB(sb)->s_qf_names[i]) {
2101 			int ret = ext4_quota_on_mount(sb, i);
2102 			if (ret < 0)
2103 				ext4_msg(sb, KERN_ERR,
2104 					"Cannot turn on journaled "
2105 					"quota: error %d", ret);
2106 		}
2107 	}
2108 #endif
2109 
2110 	while (es->s_last_orphan) {
2111 		struct inode *inode;
2112 
2113 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2114 		if (IS_ERR(inode)) {
2115 			es->s_last_orphan = 0;
2116 			break;
2117 		}
2118 
2119 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2120 		dquot_initialize(inode);
2121 		if (inode->i_nlink) {
2122 			ext4_msg(sb, KERN_DEBUG,
2123 				"%s: truncating inode %lu to %lld bytes",
2124 				__func__, inode->i_ino, inode->i_size);
2125 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2126 				  inode->i_ino, inode->i_size);
2127 			ext4_truncate(inode);
2128 			nr_truncates++;
2129 		} else {
2130 			ext4_msg(sb, KERN_DEBUG,
2131 				"%s: deleting unreferenced inode %lu",
2132 				__func__, inode->i_ino);
2133 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2134 				  inode->i_ino);
2135 			nr_orphans++;
2136 		}
2137 		iput(inode);  /* The delete magic happens here! */
2138 	}
2139 
2140 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2141 
2142 	if (nr_orphans)
2143 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2144 		       PLURAL(nr_orphans));
2145 	if (nr_truncates)
2146 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2147 		       PLURAL(nr_truncates));
2148 #ifdef CONFIG_QUOTA
2149 	/* Turn quotas off */
2150 	for (i = 0; i < MAXQUOTAS; i++) {
2151 		if (sb_dqopt(sb)->files[i])
2152 			dquot_quota_off(sb, i);
2153 	}
2154 #endif
2155 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2156 }
2157 
2158 /*
2159  * Maximal extent format file size.
2160  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2161  * extent format containers, within a sector_t, and within i_blocks
2162  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2163  * so that won't be a limiting factor.
2164  *
2165  * However there is other limiting factor. We do store extents in the form
2166  * of starting block and length, hence the resulting length of the extent
2167  * covering maximum file size must fit into on-disk format containers as
2168  * well. Given that length is always by 1 unit bigger than max unit (because
2169  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2170  *
2171  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2172  */
2173 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2174 {
2175 	loff_t res;
2176 	loff_t upper_limit = MAX_LFS_FILESIZE;
2177 
2178 	/* small i_blocks in vfs inode? */
2179 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2180 		/*
2181 		 * CONFIG_LBDAF is not enabled implies the inode
2182 		 * i_block represent total blocks in 512 bytes
2183 		 * 32 == size of vfs inode i_blocks * 8
2184 		 */
2185 		upper_limit = (1LL << 32) - 1;
2186 
2187 		/* total blocks in file system block size */
2188 		upper_limit >>= (blkbits - 9);
2189 		upper_limit <<= blkbits;
2190 	}
2191 
2192 	/*
2193 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2194 	 * by one fs block, so ee_len can cover the extent of maximum file
2195 	 * size
2196 	 */
2197 	res = (1LL << 32) - 1;
2198 	res <<= blkbits;
2199 
2200 	/* Sanity check against vm- & vfs- imposed limits */
2201 	if (res > upper_limit)
2202 		res = upper_limit;
2203 
2204 	return res;
2205 }
2206 
2207 /*
2208  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2209  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2210  * We need to be 1 filesystem block less than the 2^48 sector limit.
2211  */
2212 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2213 {
2214 	loff_t res = EXT4_NDIR_BLOCKS;
2215 	int meta_blocks;
2216 	loff_t upper_limit;
2217 	/* This is calculated to be the largest file size for a dense, block
2218 	 * mapped file such that the file's total number of 512-byte sectors,
2219 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2220 	 *
2221 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2222 	 * number of 512-byte sectors of the file.
2223 	 */
2224 
2225 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2226 		/*
2227 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2228 		 * the inode i_block field represents total file blocks in
2229 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2230 		 */
2231 		upper_limit = (1LL << 32) - 1;
2232 
2233 		/* total blocks in file system block size */
2234 		upper_limit >>= (bits - 9);
2235 
2236 	} else {
2237 		/*
2238 		 * We use 48 bit ext4_inode i_blocks
2239 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2240 		 * represent total number of blocks in
2241 		 * file system block size
2242 		 */
2243 		upper_limit = (1LL << 48) - 1;
2244 
2245 	}
2246 
2247 	/* indirect blocks */
2248 	meta_blocks = 1;
2249 	/* double indirect blocks */
2250 	meta_blocks += 1 + (1LL << (bits-2));
2251 	/* tripple indirect blocks */
2252 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2253 
2254 	upper_limit -= meta_blocks;
2255 	upper_limit <<= bits;
2256 
2257 	res += 1LL << (bits-2);
2258 	res += 1LL << (2*(bits-2));
2259 	res += 1LL << (3*(bits-2));
2260 	res <<= bits;
2261 	if (res > upper_limit)
2262 		res = upper_limit;
2263 
2264 	if (res > MAX_LFS_FILESIZE)
2265 		res = MAX_LFS_FILESIZE;
2266 
2267 	return res;
2268 }
2269 
2270 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2271 				   ext4_fsblk_t logical_sb_block, int nr)
2272 {
2273 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2274 	ext4_group_t bg, first_meta_bg;
2275 	int has_super = 0;
2276 
2277 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2278 
2279 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2280 	    nr < first_meta_bg)
2281 		return logical_sb_block + nr + 1;
2282 	bg = sbi->s_desc_per_block * nr;
2283 	if (ext4_bg_has_super(sb, bg))
2284 		has_super = 1;
2285 
2286 	return (has_super + ext4_group_first_block_no(sb, bg));
2287 }
2288 
2289 /**
2290  * ext4_get_stripe_size: Get the stripe size.
2291  * @sbi: In memory super block info
2292  *
2293  * If we have specified it via mount option, then
2294  * use the mount option value. If the value specified at mount time is
2295  * greater than the blocks per group use the super block value.
2296  * If the super block value is greater than blocks per group return 0.
2297  * Allocator needs it be less than blocks per group.
2298  *
2299  */
2300 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2301 {
2302 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2303 	unsigned long stripe_width =
2304 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2305 	int ret;
2306 
2307 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2308 		ret = sbi->s_stripe;
2309 	else if (stripe_width <= sbi->s_blocks_per_group)
2310 		ret = stripe_width;
2311 	else if (stride <= sbi->s_blocks_per_group)
2312 		ret = stride;
2313 	else
2314 		ret = 0;
2315 
2316 	/*
2317 	 * If the stripe width is 1, this makes no sense and
2318 	 * we set it to 0 to turn off stripe handling code.
2319 	 */
2320 	if (ret <= 1)
2321 		ret = 0;
2322 
2323 	return ret;
2324 }
2325 
2326 /* sysfs supprt */
2327 
2328 struct ext4_attr {
2329 	struct attribute attr;
2330 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2331 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2332 			 const char *, size_t);
2333 	int offset;
2334 };
2335 
2336 static int parse_strtoul(const char *buf,
2337 		unsigned long max, unsigned long *value)
2338 {
2339 	char *endp;
2340 
2341 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2342 	endp = skip_spaces(endp);
2343 	if (*endp || *value > max)
2344 		return -EINVAL;
2345 
2346 	return 0;
2347 }
2348 
2349 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2350 					      struct ext4_sb_info *sbi,
2351 					      char *buf)
2352 {
2353 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2354 		(s64) EXT4_C2B(sbi,
2355 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2356 }
2357 
2358 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2359 					 struct ext4_sb_info *sbi, char *buf)
2360 {
2361 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2362 
2363 	if (!sb->s_bdev->bd_part)
2364 		return snprintf(buf, PAGE_SIZE, "0\n");
2365 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2366 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2367 			 sbi->s_sectors_written_start) >> 1);
2368 }
2369 
2370 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2371 					  struct ext4_sb_info *sbi, char *buf)
2372 {
2373 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2374 
2375 	if (!sb->s_bdev->bd_part)
2376 		return snprintf(buf, PAGE_SIZE, "0\n");
2377 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2378 			(unsigned long long)(sbi->s_kbytes_written +
2379 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2380 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2381 }
2382 
2383 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2384 					  struct ext4_sb_info *sbi,
2385 					  const char *buf, size_t count)
2386 {
2387 	unsigned long t;
2388 
2389 	if (parse_strtoul(buf, 0x40000000, &t))
2390 		return -EINVAL;
2391 
2392 	if (t && !is_power_of_2(t))
2393 		return -EINVAL;
2394 
2395 	sbi->s_inode_readahead_blks = t;
2396 	return count;
2397 }
2398 
2399 static ssize_t sbi_ui_show(struct ext4_attr *a,
2400 			   struct ext4_sb_info *sbi, char *buf)
2401 {
2402 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2403 
2404 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2405 }
2406 
2407 static ssize_t sbi_ui_store(struct ext4_attr *a,
2408 			    struct ext4_sb_info *sbi,
2409 			    const char *buf, size_t count)
2410 {
2411 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2412 	unsigned long t;
2413 
2414 	if (parse_strtoul(buf, 0xffffffff, &t))
2415 		return -EINVAL;
2416 	*ui = t;
2417 	return count;
2418 }
2419 
2420 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2421 static struct ext4_attr ext4_attr_##_name = {			\
2422 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2423 	.show	= _show,					\
2424 	.store	= _store,					\
2425 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2426 }
2427 #define EXT4_ATTR(name, mode, show, store) \
2428 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2429 
2430 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2431 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2432 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2433 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2434 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2435 #define ATTR_LIST(name) &ext4_attr_##name.attr
2436 
2437 EXT4_RO_ATTR(delayed_allocation_blocks);
2438 EXT4_RO_ATTR(session_write_kbytes);
2439 EXT4_RO_ATTR(lifetime_write_kbytes);
2440 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2441 		 inode_readahead_blks_store, s_inode_readahead_blks);
2442 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2443 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2444 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2445 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2446 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2447 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2448 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2449 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2450 
2451 static struct attribute *ext4_attrs[] = {
2452 	ATTR_LIST(delayed_allocation_blocks),
2453 	ATTR_LIST(session_write_kbytes),
2454 	ATTR_LIST(lifetime_write_kbytes),
2455 	ATTR_LIST(inode_readahead_blks),
2456 	ATTR_LIST(inode_goal),
2457 	ATTR_LIST(mb_stats),
2458 	ATTR_LIST(mb_max_to_scan),
2459 	ATTR_LIST(mb_min_to_scan),
2460 	ATTR_LIST(mb_order2_req),
2461 	ATTR_LIST(mb_stream_req),
2462 	ATTR_LIST(mb_group_prealloc),
2463 	ATTR_LIST(max_writeback_mb_bump),
2464 	NULL,
2465 };
2466 
2467 /* Features this copy of ext4 supports */
2468 EXT4_INFO_ATTR(lazy_itable_init);
2469 EXT4_INFO_ATTR(batched_discard);
2470 
2471 static struct attribute *ext4_feat_attrs[] = {
2472 	ATTR_LIST(lazy_itable_init),
2473 	ATTR_LIST(batched_discard),
2474 	NULL,
2475 };
2476 
2477 static ssize_t ext4_attr_show(struct kobject *kobj,
2478 			      struct attribute *attr, char *buf)
2479 {
2480 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2481 						s_kobj);
2482 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2483 
2484 	return a->show ? a->show(a, sbi, buf) : 0;
2485 }
2486 
2487 static ssize_t ext4_attr_store(struct kobject *kobj,
2488 			       struct attribute *attr,
2489 			       const char *buf, size_t len)
2490 {
2491 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2492 						s_kobj);
2493 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2494 
2495 	return a->store ? a->store(a, sbi, buf, len) : 0;
2496 }
2497 
2498 static void ext4_sb_release(struct kobject *kobj)
2499 {
2500 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2501 						s_kobj);
2502 	complete(&sbi->s_kobj_unregister);
2503 }
2504 
2505 static const struct sysfs_ops ext4_attr_ops = {
2506 	.show	= ext4_attr_show,
2507 	.store	= ext4_attr_store,
2508 };
2509 
2510 static struct kobj_type ext4_ktype = {
2511 	.default_attrs	= ext4_attrs,
2512 	.sysfs_ops	= &ext4_attr_ops,
2513 	.release	= ext4_sb_release,
2514 };
2515 
2516 static void ext4_feat_release(struct kobject *kobj)
2517 {
2518 	complete(&ext4_feat->f_kobj_unregister);
2519 }
2520 
2521 static struct kobj_type ext4_feat_ktype = {
2522 	.default_attrs	= ext4_feat_attrs,
2523 	.sysfs_ops	= &ext4_attr_ops,
2524 	.release	= ext4_feat_release,
2525 };
2526 
2527 /*
2528  * Check whether this filesystem can be mounted based on
2529  * the features present and the RDONLY/RDWR mount requested.
2530  * Returns 1 if this filesystem can be mounted as requested,
2531  * 0 if it cannot be.
2532  */
2533 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2534 {
2535 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2536 		ext4_msg(sb, KERN_ERR,
2537 			"Couldn't mount because of "
2538 			"unsupported optional features (%x)",
2539 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2540 			~EXT4_FEATURE_INCOMPAT_SUPP));
2541 		return 0;
2542 	}
2543 
2544 	if (readonly)
2545 		return 1;
2546 
2547 	/* Check that feature set is OK for a read-write mount */
2548 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2549 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2550 			 "unsupported optional features (%x)",
2551 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2552 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2553 		return 0;
2554 	}
2555 	/*
2556 	 * Large file size enabled file system can only be mounted
2557 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2558 	 */
2559 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2560 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2561 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2562 				 "cannot be mounted RDWR without "
2563 				 "CONFIG_LBDAF");
2564 			return 0;
2565 		}
2566 	}
2567 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2568 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2569 		ext4_msg(sb, KERN_ERR,
2570 			 "Can't support bigalloc feature without "
2571 			 "extents feature\n");
2572 		return 0;
2573 	}
2574 	return 1;
2575 }
2576 
2577 /*
2578  * This function is called once a day if we have errors logged
2579  * on the file system
2580  */
2581 static void print_daily_error_info(unsigned long arg)
2582 {
2583 	struct super_block *sb = (struct super_block *) arg;
2584 	struct ext4_sb_info *sbi;
2585 	struct ext4_super_block *es;
2586 
2587 	sbi = EXT4_SB(sb);
2588 	es = sbi->s_es;
2589 
2590 	if (es->s_error_count)
2591 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2592 			 le32_to_cpu(es->s_error_count));
2593 	if (es->s_first_error_time) {
2594 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2595 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2596 		       (int) sizeof(es->s_first_error_func),
2597 		       es->s_first_error_func,
2598 		       le32_to_cpu(es->s_first_error_line));
2599 		if (es->s_first_error_ino)
2600 			printk(": inode %u",
2601 			       le32_to_cpu(es->s_first_error_ino));
2602 		if (es->s_first_error_block)
2603 			printk(": block %llu", (unsigned long long)
2604 			       le64_to_cpu(es->s_first_error_block));
2605 		printk("\n");
2606 	}
2607 	if (es->s_last_error_time) {
2608 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2609 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2610 		       (int) sizeof(es->s_last_error_func),
2611 		       es->s_last_error_func,
2612 		       le32_to_cpu(es->s_last_error_line));
2613 		if (es->s_last_error_ino)
2614 			printk(": inode %u",
2615 			       le32_to_cpu(es->s_last_error_ino));
2616 		if (es->s_last_error_block)
2617 			printk(": block %llu", (unsigned long long)
2618 			       le64_to_cpu(es->s_last_error_block));
2619 		printk("\n");
2620 	}
2621 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2622 }
2623 
2624 /* Find next suitable group and run ext4_init_inode_table */
2625 static int ext4_run_li_request(struct ext4_li_request *elr)
2626 {
2627 	struct ext4_group_desc *gdp = NULL;
2628 	ext4_group_t group, ngroups;
2629 	struct super_block *sb;
2630 	unsigned long timeout = 0;
2631 	int ret = 0;
2632 
2633 	sb = elr->lr_super;
2634 	ngroups = EXT4_SB(sb)->s_groups_count;
2635 
2636 	for (group = elr->lr_next_group; group < ngroups; group++) {
2637 		gdp = ext4_get_group_desc(sb, group, NULL);
2638 		if (!gdp) {
2639 			ret = 1;
2640 			break;
2641 		}
2642 
2643 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2644 			break;
2645 	}
2646 
2647 	if (group == ngroups)
2648 		ret = 1;
2649 
2650 	if (!ret) {
2651 		timeout = jiffies;
2652 		ret = ext4_init_inode_table(sb, group,
2653 					    elr->lr_timeout ? 0 : 1);
2654 		if (elr->lr_timeout == 0) {
2655 			timeout = (jiffies - timeout) *
2656 				  elr->lr_sbi->s_li_wait_mult;
2657 			elr->lr_timeout = timeout;
2658 		}
2659 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2660 		elr->lr_next_group = group + 1;
2661 	}
2662 
2663 	return ret;
2664 }
2665 
2666 /*
2667  * Remove lr_request from the list_request and free the
2668  * request structure. Should be called with li_list_mtx held
2669  */
2670 static void ext4_remove_li_request(struct ext4_li_request *elr)
2671 {
2672 	struct ext4_sb_info *sbi;
2673 
2674 	if (!elr)
2675 		return;
2676 
2677 	sbi = elr->lr_sbi;
2678 
2679 	list_del(&elr->lr_request);
2680 	sbi->s_li_request = NULL;
2681 	kfree(elr);
2682 }
2683 
2684 static void ext4_unregister_li_request(struct super_block *sb)
2685 {
2686 	mutex_lock(&ext4_li_mtx);
2687 	if (!ext4_li_info) {
2688 		mutex_unlock(&ext4_li_mtx);
2689 		return;
2690 	}
2691 
2692 	mutex_lock(&ext4_li_info->li_list_mtx);
2693 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2694 	mutex_unlock(&ext4_li_info->li_list_mtx);
2695 	mutex_unlock(&ext4_li_mtx);
2696 }
2697 
2698 static struct task_struct *ext4_lazyinit_task;
2699 
2700 /*
2701  * This is the function where ext4lazyinit thread lives. It walks
2702  * through the request list searching for next scheduled filesystem.
2703  * When such a fs is found, run the lazy initialization request
2704  * (ext4_rn_li_request) and keep track of the time spend in this
2705  * function. Based on that time we compute next schedule time of
2706  * the request. When walking through the list is complete, compute
2707  * next waking time and put itself into sleep.
2708  */
2709 static int ext4_lazyinit_thread(void *arg)
2710 {
2711 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2712 	struct list_head *pos, *n;
2713 	struct ext4_li_request *elr;
2714 	unsigned long next_wakeup, cur;
2715 
2716 	BUG_ON(NULL == eli);
2717 
2718 cont_thread:
2719 	while (true) {
2720 		next_wakeup = MAX_JIFFY_OFFSET;
2721 
2722 		mutex_lock(&eli->li_list_mtx);
2723 		if (list_empty(&eli->li_request_list)) {
2724 			mutex_unlock(&eli->li_list_mtx);
2725 			goto exit_thread;
2726 		}
2727 
2728 		list_for_each_safe(pos, n, &eli->li_request_list) {
2729 			elr = list_entry(pos, struct ext4_li_request,
2730 					 lr_request);
2731 
2732 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2733 				if (ext4_run_li_request(elr) != 0) {
2734 					/* error, remove the lazy_init job */
2735 					ext4_remove_li_request(elr);
2736 					continue;
2737 				}
2738 			}
2739 
2740 			if (time_before(elr->lr_next_sched, next_wakeup))
2741 				next_wakeup = elr->lr_next_sched;
2742 		}
2743 		mutex_unlock(&eli->li_list_mtx);
2744 
2745 		try_to_freeze();
2746 
2747 		cur = jiffies;
2748 		if ((time_after_eq(cur, next_wakeup)) ||
2749 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2750 			cond_resched();
2751 			continue;
2752 		}
2753 
2754 		schedule_timeout_interruptible(next_wakeup - cur);
2755 
2756 		if (kthread_should_stop()) {
2757 			ext4_clear_request_list();
2758 			goto exit_thread;
2759 		}
2760 	}
2761 
2762 exit_thread:
2763 	/*
2764 	 * It looks like the request list is empty, but we need
2765 	 * to check it under the li_list_mtx lock, to prevent any
2766 	 * additions into it, and of course we should lock ext4_li_mtx
2767 	 * to atomically free the list and ext4_li_info, because at
2768 	 * this point another ext4 filesystem could be registering
2769 	 * new one.
2770 	 */
2771 	mutex_lock(&ext4_li_mtx);
2772 	mutex_lock(&eli->li_list_mtx);
2773 	if (!list_empty(&eli->li_request_list)) {
2774 		mutex_unlock(&eli->li_list_mtx);
2775 		mutex_unlock(&ext4_li_mtx);
2776 		goto cont_thread;
2777 	}
2778 	mutex_unlock(&eli->li_list_mtx);
2779 	kfree(ext4_li_info);
2780 	ext4_li_info = NULL;
2781 	mutex_unlock(&ext4_li_mtx);
2782 
2783 	return 0;
2784 }
2785 
2786 static void ext4_clear_request_list(void)
2787 {
2788 	struct list_head *pos, *n;
2789 	struct ext4_li_request *elr;
2790 
2791 	mutex_lock(&ext4_li_info->li_list_mtx);
2792 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2793 		elr = list_entry(pos, struct ext4_li_request,
2794 				 lr_request);
2795 		ext4_remove_li_request(elr);
2796 	}
2797 	mutex_unlock(&ext4_li_info->li_list_mtx);
2798 }
2799 
2800 static int ext4_run_lazyinit_thread(void)
2801 {
2802 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2803 					 ext4_li_info, "ext4lazyinit");
2804 	if (IS_ERR(ext4_lazyinit_task)) {
2805 		int err = PTR_ERR(ext4_lazyinit_task);
2806 		ext4_clear_request_list();
2807 		kfree(ext4_li_info);
2808 		ext4_li_info = NULL;
2809 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2810 				 "initialization thread\n",
2811 				 err);
2812 		return err;
2813 	}
2814 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2815 	return 0;
2816 }
2817 
2818 /*
2819  * Check whether it make sense to run itable init. thread or not.
2820  * If there is at least one uninitialized inode table, return
2821  * corresponding group number, else the loop goes through all
2822  * groups and return total number of groups.
2823  */
2824 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2825 {
2826 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2827 	struct ext4_group_desc *gdp = NULL;
2828 
2829 	for (group = 0; group < ngroups; group++) {
2830 		gdp = ext4_get_group_desc(sb, group, NULL);
2831 		if (!gdp)
2832 			continue;
2833 
2834 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2835 			break;
2836 	}
2837 
2838 	return group;
2839 }
2840 
2841 static int ext4_li_info_new(void)
2842 {
2843 	struct ext4_lazy_init *eli = NULL;
2844 
2845 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2846 	if (!eli)
2847 		return -ENOMEM;
2848 
2849 	INIT_LIST_HEAD(&eli->li_request_list);
2850 	mutex_init(&eli->li_list_mtx);
2851 
2852 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2853 
2854 	ext4_li_info = eli;
2855 
2856 	return 0;
2857 }
2858 
2859 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2860 					    ext4_group_t start)
2861 {
2862 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2863 	struct ext4_li_request *elr;
2864 	unsigned long rnd;
2865 
2866 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2867 	if (!elr)
2868 		return NULL;
2869 
2870 	elr->lr_super = sb;
2871 	elr->lr_sbi = sbi;
2872 	elr->lr_next_group = start;
2873 
2874 	/*
2875 	 * Randomize first schedule time of the request to
2876 	 * spread the inode table initialization requests
2877 	 * better.
2878 	 */
2879 	get_random_bytes(&rnd, sizeof(rnd));
2880 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
2881 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2882 
2883 	return elr;
2884 }
2885 
2886 static int ext4_register_li_request(struct super_block *sb,
2887 				    ext4_group_t first_not_zeroed)
2888 {
2889 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2890 	struct ext4_li_request *elr;
2891 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2892 	int ret = 0;
2893 
2894 	if (sbi->s_li_request != NULL) {
2895 		/*
2896 		 * Reset timeout so it can be computed again, because
2897 		 * s_li_wait_mult might have changed.
2898 		 */
2899 		sbi->s_li_request->lr_timeout = 0;
2900 		return 0;
2901 	}
2902 
2903 	if (first_not_zeroed == ngroups ||
2904 	    (sb->s_flags & MS_RDONLY) ||
2905 	    !test_opt(sb, INIT_INODE_TABLE))
2906 		return 0;
2907 
2908 	elr = ext4_li_request_new(sb, first_not_zeroed);
2909 	if (!elr)
2910 		return -ENOMEM;
2911 
2912 	mutex_lock(&ext4_li_mtx);
2913 
2914 	if (NULL == ext4_li_info) {
2915 		ret = ext4_li_info_new();
2916 		if (ret)
2917 			goto out;
2918 	}
2919 
2920 	mutex_lock(&ext4_li_info->li_list_mtx);
2921 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2922 	mutex_unlock(&ext4_li_info->li_list_mtx);
2923 
2924 	sbi->s_li_request = elr;
2925 	/*
2926 	 * set elr to NULL here since it has been inserted to
2927 	 * the request_list and the removal and free of it is
2928 	 * handled by ext4_clear_request_list from now on.
2929 	 */
2930 	elr = NULL;
2931 
2932 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2933 		ret = ext4_run_lazyinit_thread();
2934 		if (ret)
2935 			goto out;
2936 	}
2937 out:
2938 	mutex_unlock(&ext4_li_mtx);
2939 	if (ret)
2940 		kfree(elr);
2941 	return ret;
2942 }
2943 
2944 /*
2945  * We do not need to lock anything since this is called on
2946  * module unload.
2947  */
2948 static void ext4_destroy_lazyinit_thread(void)
2949 {
2950 	/*
2951 	 * If thread exited earlier
2952 	 * there's nothing to be done.
2953 	 */
2954 	if (!ext4_li_info || !ext4_lazyinit_task)
2955 		return;
2956 
2957 	kthread_stop(ext4_lazyinit_task);
2958 }
2959 
2960 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2961 {
2962 	char *orig_data = kstrdup(data, GFP_KERNEL);
2963 	struct buffer_head *bh;
2964 	struct ext4_super_block *es = NULL;
2965 	struct ext4_sb_info *sbi;
2966 	ext4_fsblk_t block;
2967 	ext4_fsblk_t sb_block = get_sb_block(&data);
2968 	ext4_fsblk_t logical_sb_block;
2969 	unsigned long offset = 0;
2970 	unsigned long journal_devnum = 0;
2971 	unsigned long def_mount_opts;
2972 	struct inode *root;
2973 	char *cp;
2974 	const char *descr;
2975 	int ret = -ENOMEM;
2976 	int blocksize, clustersize;
2977 	unsigned int db_count;
2978 	unsigned int i;
2979 	int needs_recovery, has_huge_files, has_bigalloc;
2980 	__u64 blocks_count;
2981 	int err;
2982 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2983 	ext4_group_t first_not_zeroed;
2984 
2985 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2986 	if (!sbi)
2987 		goto out_free_orig;
2988 
2989 	sbi->s_blockgroup_lock =
2990 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2991 	if (!sbi->s_blockgroup_lock) {
2992 		kfree(sbi);
2993 		goto out_free_orig;
2994 	}
2995 	sb->s_fs_info = sbi;
2996 	sbi->s_mount_opt = 0;
2997 	sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
2998 	sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
2999 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3000 	sbi->s_sb_block = sb_block;
3001 	if (sb->s_bdev->bd_part)
3002 		sbi->s_sectors_written_start =
3003 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3004 
3005 	/* Cleanup superblock name */
3006 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3007 		*cp = '!';
3008 
3009 	ret = -EINVAL;
3010 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3011 	if (!blocksize) {
3012 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3013 		goto out_fail;
3014 	}
3015 
3016 	/*
3017 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3018 	 * block sizes.  We need to calculate the offset from buffer start.
3019 	 */
3020 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3021 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3022 		offset = do_div(logical_sb_block, blocksize);
3023 	} else {
3024 		logical_sb_block = sb_block;
3025 	}
3026 
3027 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3028 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3029 		goto out_fail;
3030 	}
3031 	/*
3032 	 * Note: s_es must be initialized as soon as possible because
3033 	 *       some ext4 macro-instructions depend on its value
3034 	 */
3035 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3036 	sbi->s_es = es;
3037 	sb->s_magic = le16_to_cpu(es->s_magic);
3038 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3039 		goto cantfind_ext4;
3040 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3041 
3042 	/* Set defaults before we parse the mount options */
3043 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3044 	set_opt(sb, INIT_INODE_TABLE);
3045 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3046 		set_opt(sb, DEBUG);
3047 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3048 		set_opt(sb, GRPID);
3049 	if (def_mount_opts & EXT4_DEFM_UID16)
3050 		set_opt(sb, NO_UID32);
3051 	/* xattr user namespace & acls are now defaulted on */
3052 #ifdef CONFIG_EXT4_FS_XATTR
3053 	set_opt(sb, XATTR_USER);
3054 #endif
3055 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3056 	set_opt(sb, POSIX_ACL);
3057 #endif
3058 	set_opt(sb, MBLK_IO_SUBMIT);
3059 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3060 		set_opt(sb, JOURNAL_DATA);
3061 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3062 		set_opt(sb, ORDERED_DATA);
3063 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3064 		set_opt(sb, WRITEBACK_DATA);
3065 
3066 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3067 		set_opt(sb, ERRORS_PANIC);
3068 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3069 		set_opt(sb, ERRORS_CONT);
3070 	else
3071 		set_opt(sb, ERRORS_RO);
3072 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3073 		set_opt(sb, BLOCK_VALIDITY);
3074 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3075 		set_opt(sb, DISCARD);
3076 
3077 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3078 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3079 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3080 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3081 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3082 
3083 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3084 		set_opt(sb, BARRIER);
3085 
3086 	/*
3087 	 * enable delayed allocation by default
3088 	 * Use -o nodelalloc to turn it off
3089 	 */
3090 	if (!IS_EXT3_SB(sb) &&
3091 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3092 		set_opt(sb, DELALLOC);
3093 
3094 	/*
3095 	 * set default s_li_wait_mult for lazyinit, for the case there is
3096 	 * no mount option specified.
3097 	 */
3098 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3099 
3100 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3101 			   &journal_devnum, &journal_ioprio, 0)) {
3102 		ext4_msg(sb, KERN_WARNING,
3103 			 "failed to parse options in superblock: %s",
3104 			 sbi->s_es->s_mount_opts);
3105 	}
3106 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3107 	if (!parse_options((char *) data, sb, &journal_devnum,
3108 			   &journal_ioprio, 0))
3109 		goto failed_mount;
3110 
3111 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3112 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3113 			    "with data=journal disables delayed "
3114 			    "allocation and O_DIRECT support!\n");
3115 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3116 			ext4_msg(sb, KERN_ERR, "can't mount with "
3117 				 "both data=journal and delalloc");
3118 			goto failed_mount;
3119 		}
3120 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3121 			ext4_msg(sb, KERN_ERR, "can't mount with "
3122 				 "both data=journal and delalloc");
3123 			goto failed_mount;
3124 		}
3125 		if (test_opt(sb, DELALLOC))
3126 			clear_opt(sb, DELALLOC);
3127 	}
3128 
3129 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3130 	if (test_opt(sb, DIOREAD_NOLOCK)) {
3131 		if (blocksize < PAGE_SIZE) {
3132 			ext4_msg(sb, KERN_ERR, "can't mount with "
3133 				 "dioread_nolock if block size != PAGE_SIZE");
3134 			goto failed_mount;
3135 		}
3136 	}
3137 
3138 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3139 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3140 
3141 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3142 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3143 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3144 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3145 		ext4_msg(sb, KERN_WARNING,
3146 		       "feature flags set on rev 0 fs, "
3147 		       "running e2fsck is recommended");
3148 
3149 	if (IS_EXT2_SB(sb)) {
3150 		if (ext2_feature_set_ok(sb))
3151 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3152 				 "using the ext4 subsystem");
3153 		else {
3154 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3155 				 "to feature incompatibilities");
3156 			goto failed_mount;
3157 		}
3158 	}
3159 
3160 	if (IS_EXT3_SB(sb)) {
3161 		if (ext3_feature_set_ok(sb))
3162 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3163 				 "using the ext4 subsystem");
3164 		else {
3165 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3166 				 "to feature incompatibilities");
3167 			goto failed_mount;
3168 		}
3169 	}
3170 
3171 	/*
3172 	 * Check feature flags regardless of the revision level, since we
3173 	 * previously didn't change the revision level when setting the flags,
3174 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3175 	 */
3176 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3177 		goto failed_mount;
3178 
3179 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3180 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3181 		ext4_msg(sb, KERN_ERR,
3182 		       "Unsupported filesystem blocksize %d", blocksize);
3183 		goto failed_mount;
3184 	}
3185 
3186 	if (sb->s_blocksize != blocksize) {
3187 		/* Validate the filesystem blocksize */
3188 		if (!sb_set_blocksize(sb, blocksize)) {
3189 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3190 					blocksize);
3191 			goto failed_mount;
3192 		}
3193 
3194 		brelse(bh);
3195 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3196 		offset = do_div(logical_sb_block, blocksize);
3197 		bh = sb_bread(sb, logical_sb_block);
3198 		if (!bh) {
3199 			ext4_msg(sb, KERN_ERR,
3200 			       "Can't read superblock on 2nd try");
3201 			goto failed_mount;
3202 		}
3203 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
3204 		sbi->s_es = es;
3205 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3206 			ext4_msg(sb, KERN_ERR,
3207 			       "Magic mismatch, very weird!");
3208 			goto failed_mount;
3209 		}
3210 	}
3211 
3212 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3213 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3214 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3215 						      has_huge_files);
3216 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3217 
3218 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3219 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3220 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3221 	} else {
3222 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3223 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3224 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3225 		    (!is_power_of_2(sbi->s_inode_size)) ||
3226 		    (sbi->s_inode_size > blocksize)) {
3227 			ext4_msg(sb, KERN_ERR,
3228 			       "unsupported inode size: %d",
3229 			       sbi->s_inode_size);
3230 			goto failed_mount;
3231 		}
3232 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3233 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3234 	}
3235 
3236 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3237 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3238 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3239 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3240 		    !is_power_of_2(sbi->s_desc_size)) {
3241 			ext4_msg(sb, KERN_ERR,
3242 			       "unsupported descriptor size %lu",
3243 			       sbi->s_desc_size);
3244 			goto failed_mount;
3245 		}
3246 	} else
3247 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3248 
3249 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3250 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3251 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3252 		goto cantfind_ext4;
3253 
3254 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3255 	if (sbi->s_inodes_per_block == 0)
3256 		goto cantfind_ext4;
3257 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3258 					sbi->s_inodes_per_block;
3259 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3260 	sbi->s_sbh = bh;
3261 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3262 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3263 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3264 
3265 	for (i = 0; i < 4; i++)
3266 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3267 	sbi->s_def_hash_version = es->s_def_hash_version;
3268 	i = le32_to_cpu(es->s_flags);
3269 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3270 		sbi->s_hash_unsigned = 3;
3271 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3272 #ifdef __CHAR_UNSIGNED__
3273 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3274 		sbi->s_hash_unsigned = 3;
3275 #else
3276 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3277 #endif
3278 	}
3279 
3280 	/* Handle clustersize */
3281 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3282 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3283 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3284 	if (has_bigalloc) {
3285 		if (clustersize < blocksize) {
3286 			ext4_msg(sb, KERN_ERR,
3287 				 "cluster size (%d) smaller than "
3288 				 "block size (%d)", clustersize, blocksize);
3289 			goto failed_mount;
3290 		}
3291 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3292 			le32_to_cpu(es->s_log_block_size);
3293 		sbi->s_clusters_per_group =
3294 			le32_to_cpu(es->s_clusters_per_group);
3295 		if (sbi->s_clusters_per_group > blocksize * 8) {
3296 			ext4_msg(sb, KERN_ERR,
3297 				 "#clusters per group too big: %lu",
3298 				 sbi->s_clusters_per_group);
3299 			goto failed_mount;
3300 		}
3301 		if (sbi->s_blocks_per_group !=
3302 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3303 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3304 				 "clusters per group (%lu) inconsistent",
3305 				 sbi->s_blocks_per_group,
3306 				 sbi->s_clusters_per_group);
3307 			goto failed_mount;
3308 		}
3309 	} else {
3310 		if (clustersize != blocksize) {
3311 			ext4_warning(sb, "fragment/cluster size (%d) != "
3312 				     "block size (%d)", clustersize,
3313 				     blocksize);
3314 			clustersize = blocksize;
3315 		}
3316 		if (sbi->s_blocks_per_group > blocksize * 8) {
3317 			ext4_msg(sb, KERN_ERR,
3318 				 "#blocks per group too big: %lu",
3319 				 sbi->s_blocks_per_group);
3320 			goto failed_mount;
3321 		}
3322 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3323 		sbi->s_cluster_bits = 0;
3324 	}
3325 	sbi->s_cluster_ratio = clustersize / blocksize;
3326 
3327 	if (sbi->s_inodes_per_group > blocksize * 8) {
3328 		ext4_msg(sb, KERN_ERR,
3329 		       "#inodes per group too big: %lu",
3330 		       sbi->s_inodes_per_group);
3331 		goto failed_mount;
3332 	}
3333 
3334 	/*
3335 	 * Test whether we have more sectors than will fit in sector_t,
3336 	 * and whether the max offset is addressable by the page cache.
3337 	 */
3338 	err = generic_check_addressable(sb->s_blocksize_bits,
3339 					ext4_blocks_count(es));
3340 	if (err) {
3341 		ext4_msg(sb, KERN_ERR, "filesystem"
3342 			 " too large to mount safely on this system");
3343 		if (sizeof(sector_t) < 8)
3344 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3345 		ret = err;
3346 		goto failed_mount;
3347 	}
3348 
3349 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3350 		goto cantfind_ext4;
3351 
3352 	/* check blocks count against device size */
3353 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3354 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3355 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3356 		       "exceeds size of device (%llu blocks)",
3357 		       ext4_blocks_count(es), blocks_count);
3358 		goto failed_mount;
3359 	}
3360 
3361 	/*
3362 	 * It makes no sense for the first data block to be beyond the end
3363 	 * of the filesystem.
3364 	 */
3365 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3366 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3367 			 "block %u is beyond end of filesystem (%llu)",
3368 			 le32_to_cpu(es->s_first_data_block),
3369 			 ext4_blocks_count(es));
3370 		goto failed_mount;
3371 	}
3372 	blocks_count = (ext4_blocks_count(es) -
3373 			le32_to_cpu(es->s_first_data_block) +
3374 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3375 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3376 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3377 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3378 		       "(block count %llu, first data block %u, "
3379 		       "blocks per group %lu)", sbi->s_groups_count,
3380 		       ext4_blocks_count(es),
3381 		       le32_to_cpu(es->s_first_data_block),
3382 		       EXT4_BLOCKS_PER_GROUP(sb));
3383 		goto failed_mount;
3384 	}
3385 	sbi->s_groups_count = blocks_count;
3386 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3387 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3388 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3389 		   EXT4_DESC_PER_BLOCK(sb);
3390 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3391 					  sizeof(struct buffer_head *),
3392 					  GFP_KERNEL);
3393 	if (sbi->s_group_desc == NULL) {
3394 		ext4_msg(sb, KERN_ERR, "not enough memory");
3395 		goto failed_mount;
3396 	}
3397 
3398 	if (ext4_proc_root)
3399 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3400 
3401 	if (sbi->s_proc)
3402 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3403 				 &ext4_seq_options_fops, sb);
3404 
3405 	bgl_lock_init(sbi->s_blockgroup_lock);
3406 
3407 	for (i = 0; i < db_count; i++) {
3408 		block = descriptor_loc(sb, logical_sb_block, i);
3409 		sbi->s_group_desc[i] = sb_bread(sb, block);
3410 		if (!sbi->s_group_desc[i]) {
3411 			ext4_msg(sb, KERN_ERR,
3412 			       "can't read group descriptor %d", i);
3413 			db_count = i;
3414 			goto failed_mount2;
3415 		}
3416 	}
3417 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3418 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3419 		goto failed_mount2;
3420 	}
3421 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3422 		if (!ext4_fill_flex_info(sb)) {
3423 			ext4_msg(sb, KERN_ERR,
3424 			       "unable to initialize "
3425 			       "flex_bg meta info!");
3426 			goto failed_mount2;
3427 		}
3428 
3429 	sbi->s_gdb_count = db_count;
3430 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3431 	spin_lock_init(&sbi->s_next_gen_lock);
3432 
3433 	init_timer(&sbi->s_err_report);
3434 	sbi->s_err_report.function = print_daily_error_info;
3435 	sbi->s_err_report.data = (unsigned long) sb;
3436 
3437 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3438 			ext4_count_free_clusters(sb));
3439 	if (!err) {
3440 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3441 				ext4_count_free_inodes(sb));
3442 	}
3443 	if (!err) {
3444 		err = percpu_counter_init(&sbi->s_dirs_counter,
3445 				ext4_count_dirs(sb));
3446 	}
3447 	if (!err) {
3448 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3449 	}
3450 	if (err) {
3451 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3452 		goto failed_mount3;
3453 	}
3454 
3455 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3456 	sbi->s_max_writeback_mb_bump = 128;
3457 
3458 	/*
3459 	 * set up enough so that it can read an inode
3460 	 */
3461 	if (!test_opt(sb, NOLOAD) &&
3462 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3463 		sb->s_op = &ext4_sops;
3464 	else
3465 		sb->s_op = &ext4_nojournal_sops;
3466 	sb->s_export_op = &ext4_export_ops;
3467 	sb->s_xattr = ext4_xattr_handlers;
3468 #ifdef CONFIG_QUOTA
3469 	sb->s_qcop = &ext4_qctl_operations;
3470 	sb->dq_op = &ext4_quota_operations;
3471 #endif
3472 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3473 
3474 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3475 	mutex_init(&sbi->s_orphan_lock);
3476 	sbi->s_resize_flags = 0;
3477 
3478 	sb->s_root = NULL;
3479 
3480 	needs_recovery = (es->s_last_orphan != 0 ||
3481 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3482 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3483 
3484 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3485 	    !(sb->s_flags & MS_RDONLY))
3486 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3487 			goto failed_mount3;
3488 
3489 	/*
3490 	 * The first inode we look at is the journal inode.  Don't try
3491 	 * root first: it may be modified in the journal!
3492 	 */
3493 	if (!test_opt(sb, NOLOAD) &&
3494 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3495 		if (ext4_load_journal(sb, es, journal_devnum))
3496 			goto failed_mount3;
3497 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3498 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3499 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3500 		       "suppressed and not mounted read-only");
3501 		goto failed_mount_wq;
3502 	} else {
3503 		clear_opt(sb, DATA_FLAGS);
3504 		sbi->s_journal = NULL;
3505 		needs_recovery = 0;
3506 		goto no_journal;
3507 	}
3508 
3509 	if (ext4_blocks_count(es) > 0xffffffffULL &&
3510 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3511 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3512 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3513 		goto failed_mount_wq;
3514 	}
3515 
3516 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3517 		jbd2_journal_set_features(sbi->s_journal,
3518 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3519 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3520 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3521 		jbd2_journal_set_features(sbi->s_journal,
3522 				JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
3523 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3524 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3525 	} else {
3526 		jbd2_journal_clear_features(sbi->s_journal,
3527 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3528 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3529 	}
3530 
3531 	/* We have now updated the journal if required, so we can
3532 	 * validate the data journaling mode. */
3533 	switch (test_opt(sb, DATA_FLAGS)) {
3534 	case 0:
3535 		/* No mode set, assume a default based on the journal
3536 		 * capabilities: ORDERED_DATA if the journal can
3537 		 * cope, else JOURNAL_DATA
3538 		 */
3539 		if (jbd2_journal_check_available_features
3540 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3541 			set_opt(sb, ORDERED_DATA);
3542 		else
3543 			set_opt(sb, JOURNAL_DATA);
3544 		break;
3545 
3546 	case EXT4_MOUNT_ORDERED_DATA:
3547 	case EXT4_MOUNT_WRITEBACK_DATA:
3548 		if (!jbd2_journal_check_available_features
3549 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3550 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3551 			       "requested data journaling mode");
3552 			goto failed_mount_wq;
3553 		}
3554 	default:
3555 		break;
3556 	}
3557 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3558 
3559 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3560 
3561 	/*
3562 	 * The journal may have updated the bg summary counts, so we
3563 	 * need to update the global counters.
3564 	 */
3565 	percpu_counter_set(&sbi->s_freeclusters_counter,
3566 			   ext4_count_free_clusters(sb));
3567 	percpu_counter_set(&sbi->s_freeinodes_counter,
3568 			   ext4_count_free_inodes(sb));
3569 	percpu_counter_set(&sbi->s_dirs_counter,
3570 			   ext4_count_dirs(sb));
3571 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3572 
3573 no_journal:
3574 	/*
3575 	 * The maximum number of concurrent works can be high and
3576 	 * concurrency isn't really necessary.  Limit it to 1.
3577 	 */
3578 	EXT4_SB(sb)->dio_unwritten_wq =
3579 		alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3580 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3581 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3582 		goto failed_mount_wq;
3583 	}
3584 
3585 	/*
3586 	 * The jbd2_journal_load will have done any necessary log recovery,
3587 	 * so we can safely mount the rest of the filesystem now.
3588 	 */
3589 
3590 	root = ext4_iget(sb, EXT4_ROOT_INO);
3591 	if (IS_ERR(root)) {
3592 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3593 		ret = PTR_ERR(root);
3594 		root = NULL;
3595 		goto failed_mount4;
3596 	}
3597 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3598 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3599 		iput(root);
3600 		goto failed_mount4;
3601 	}
3602 	sb->s_root = d_make_root(root);
3603 	if (!sb->s_root) {
3604 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3605 		ret = -ENOMEM;
3606 		goto failed_mount4;
3607 	}
3608 
3609 	ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
3610 
3611 	/* determine the minimum size of new large inodes, if present */
3612 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3613 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3614 						     EXT4_GOOD_OLD_INODE_SIZE;
3615 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3616 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3617 			if (sbi->s_want_extra_isize <
3618 			    le16_to_cpu(es->s_want_extra_isize))
3619 				sbi->s_want_extra_isize =
3620 					le16_to_cpu(es->s_want_extra_isize);
3621 			if (sbi->s_want_extra_isize <
3622 			    le16_to_cpu(es->s_min_extra_isize))
3623 				sbi->s_want_extra_isize =
3624 					le16_to_cpu(es->s_min_extra_isize);
3625 		}
3626 	}
3627 	/* Check if enough inode space is available */
3628 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3629 							sbi->s_inode_size) {
3630 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3631 						       EXT4_GOOD_OLD_INODE_SIZE;
3632 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3633 			 "available");
3634 	}
3635 
3636 	err = ext4_setup_system_zone(sb);
3637 	if (err) {
3638 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3639 			 "zone (%d)", err);
3640 		goto failed_mount4a;
3641 	}
3642 
3643 	ext4_ext_init(sb);
3644 	err = ext4_mb_init(sb, needs_recovery);
3645 	if (err) {
3646 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3647 			 err);
3648 		goto failed_mount5;
3649 	}
3650 
3651 	err = ext4_register_li_request(sb, first_not_zeroed);
3652 	if (err)
3653 		goto failed_mount6;
3654 
3655 	sbi->s_kobj.kset = ext4_kset;
3656 	init_completion(&sbi->s_kobj_unregister);
3657 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3658 				   "%s", sb->s_id);
3659 	if (err)
3660 		goto failed_mount7;
3661 
3662 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3663 	ext4_orphan_cleanup(sb, es);
3664 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3665 	if (needs_recovery) {
3666 		ext4_msg(sb, KERN_INFO, "recovery complete");
3667 		ext4_mark_recovery_complete(sb, es);
3668 	}
3669 	if (EXT4_SB(sb)->s_journal) {
3670 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3671 			descr = " journalled data mode";
3672 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3673 			descr = " ordered data mode";
3674 		else
3675 			descr = " writeback data mode";
3676 	} else
3677 		descr = "out journal";
3678 
3679 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3680 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3681 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3682 
3683 	if (es->s_error_count)
3684 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3685 
3686 	kfree(orig_data);
3687 	return 0;
3688 
3689 cantfind_ext4:
3690 	if (!silent)
3691 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3692 	goto failed_mount;
3693 
3694 failed_mount7:
3695 	ext4_unregister_li_request(sb);
3696 failed_mount6:
3697 	ext4_mb_release(sb);
3698 failed_mount5:
3699 	ext4_ext_release(sb);
3700 	ext4_release_system_zone(sb);
3701 failed_mount4a:
3702 	dput(sb->s_root);
3703 	sb->s_root = NULL;
3704 failed_mount4:
3705 	ext4_msg(sb, KERN_ERR, "mount failed");
3706 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3707 failed_mount_wq:
3708 	if (sbi->s_journal) {
3709 		jbd2_journal_destroy(sbi->s_journal);
3710 		sbi->s_journal = NULL;
3711 	}
3712 failed_mount3:
3713 	del_timer(&sbi->s_err_report);
3714 	if (sbi->s_flex_groups)
3715 		ext4_kvfree(sbi->s_flex_groups);
3716 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
3717 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
3718 	percpu_counter_destroy(&sbi->s_dirs_counter);
3719 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
3720 	if (sbi->s_mmp_tsk)
3721 		kthread_stop(sbi->s_mmp_tsk);
3722 failed_mount2:
3723 	for (i = 0; i < db_count; i++)
3724 		brelse(sbi->s_group_desc[i]);
3725 	ext4_kvfree(sbi->s_group_desc);
3726 failed_mount:
3727 	if (sbi->s_proc) {
3728 		remove_proc_entry("options", sbi->s_proc);
3729 		remove_proc_entry(sb->s_id, ext4_proc_root);
3730 	}
3731 #ifdef CONFIG_QUOTA
3732 	for (i = 0; i < MAXQUOTAS; i++)
3733 		kfree(sbi->s_qf_names[i]);
3734 #endif
3735 	ext4_blkdev_remove(sbi);
3736 	brelse(bh);
3737 out_fail:
3738 	sb->s_fs_info = NULL;
3739 	kfree(sbi->s_blockgroup_lock);
3740 	kfree(sbi);
3741 out_free_orig:
3742 	kfree(orig_data);
3743 	return ret;
3744 }
3745 
3746 /*
3747  * Setup any per-fs journal parameters now.  We'll do this both on
3748  * initial mount, once the journal has been initialised but before we've
3749  * done any recovery; and again on any subsequent remount.
3750  */
3751 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3752 {
3753 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3754 
3755 	journal->j_commit_interval = sbi->s_commit_interval;
3756 	journal->j_min_batch_time = sbi->s_min_batch_time;
3757 	journal->j_max_batch_time = sbi->s_max_batch_time;
3758 
3759 	write_lock(&journal->j_state_lock);
3760 	if (test_opt(sb, BARRIER))
3761 		journal->j_flags |= JBD2_BARRIER;
3762 	else
3763 		journal->j_flags &= ~JBD2_BARRIER;
3764 	if (test_opt(sb, DATA_ERR_ABORT))
3765 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3766 	else
3767 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3768 	write_unlock(&journal->j_state_lock);
3769 }
3770 
3771 static journal_t *ext4_get_journal(struct super_block *sb,
3772 				   unsigned int journal_inum)
3773 {
3774 	struct inode *journal_inode;
3775 	journal_t *journal;
3776 
3777 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3778 
3779 	/* First, test for the existence of a valid inode on disk.  Bad
3780 	 * things happen if we iget() an unused inode, as the subsequent
3781 	 * iput() will try to delete it. */
3782 
3783 	journal_inode = ext4_iget(sb, journal_inum);
3784 	if (IS_ERR(journal_inode)) {
3785 		ext4_msg(sb, KERN_ERR, "no journal found");
3786 		return NULL;
3787 	}
3788 	if (!journal_inode->i_nlink) {
3789 		make_bad_inode(journal_inode);
3790 		iput(journal_inode);
3791 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3792 		return NULL;
3793 	}
3794 
3795 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3796 		  journal_inode, journal_inode->i_size);
3797 	if (!S_ISREG(journal_inode->i_mode)) {
3798 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
3799 		iput(journal_inode);
3800 		return NULL;
3801 	}
3802 
3803 	journal = jbd2_journal_init_inode(journal_inode);
3804 	if (!journal) {
3805 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3806 		iput(journal_inode);
3807 		return NULL;
3808 	}
3809 	journal->j_private = sb;
3810 	ext4_init_journal_params(sb, journal);
3811 	return journal;
3812 }
3813 
3814 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3815 				       dev_t j_dev)
3816 {
3817 	struct buffer_head *bh;
3818 	journal_t *journal;
3819 	ext4_fsblk_t start;
3820 	ext4_fsblk_t len;
3821 	int hblock, blocksize;
3822 	ext4_fsblk_t sb_block;
3823 	unsigned long offset;
3824 	struct ext4_super_block *es;
3825 	struct block_device *bdev;
3826 
3827 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3828 
3829 	bdev = ext4_blkdev_get(j_dev, sb);
3830 	if (bdev == NULL)
3831 		return NULL;
3832 
3833 	blocksize = sb->s_blocksize;
3834 	hblock = bdev_logical_block_size(bdev);
3835 	if (blocksize < hblock) {
3836 		ext4_msg(sb, KERN_ERR,
3837 			"blocksize too small for journal device");
3838 		goto out_bdev;
3839 	}
3840 
3841 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3842 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3843 	set_blocksize(bdev, blocksize);
3844 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
3845 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3846 		       "external journal");
3847 		goto out_bdev;
3848 	}
3849 
3850 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3851 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3852 	    !(le32_to_cpu(es->s_feature_incompat) &
3853 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3854 		ext4_msg(sb, KERN_ERR, "external journal has "
3855 					"bad superblock");
3856 		brelse(bh);
3857 		goto out_bdev;
3858 	}
3859 
3860 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3861 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3862 		brelse(bh);
3863 		goto out_bdev;
3864 	}
3865 
3866 	len = ext4_blocks_count(es);
3867 	start = sb_block + 1;
3868 	brelse(bh);	/* we're done with the superblock */
3869 
3870 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3871 					start, len, blocksize);
3872 	if (!journal) {
3873 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
3874 		goto out_bdev;
3875 	}
3876 	journal->j_private = sb;
3877 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
3878 	wait_on_buffer(journal->j_sb_buffer);
3879 	if (!buffer_uptodate(journal->j_sb_buffer)) {
3880 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3881 		goto out_journal;
3882 	}
3883 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3884 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
3885 					"user (unsupported) - %d",
3886 			be32_to_cpu(journal->j_superblock->s_nr_users));
3887 		goto out_journal;
3888 	}
3889 	EXT4_SB(sb)->journal_bdev = bdev;
3890 	ext4_init_journal_params(sb, journal);
3891 	return journal;
3892 
3893 out_journal:
3894 	jbd2_journal_destroy(journal);
3895 out_bdev:
3896 	ext4_blkdev_put(bdev);
3897 	return NULL;
3898 }
3899 
3900 static int ext4_load_journal(struct super_block *sb,
3901 			     struct ext4_super_block *es,
3902 			     unsigned long journal_devnum)
3903 {
3904 	journal_t *journal;
3905 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3906 	dev_t journal_dev;
3907 	int err = 0;
3908 	int really_read_only;
3909 
3910 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3911 
3912 	if (journal_devnum &&
3913 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3914 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3915 			"numbers have changed");
3916 		journal_dev = new_decode_dev(journal_devnum);
3917 	} else
3918 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3919 
3920 	really_read_only = bdev_read_only(sb->s_bdev);
3921 
3922 	/*
3923 	 * Are we loading a blank journal or performing recovery after a
3924 	 * crash?  For recovery, we need to check in advance whether we
3925 	 * can get read-write access to the device.
3926 	 */
3927 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3928 		if (sb->s_flags & MS_RDONLY) {
3929 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
3930 					"required on readonly filesystem");
3931 			if (really_read_only) {
3932 				ext4_msg(sb, KERN_ERR, "write access "
3933 					"unavailable, cannot proceed");
3934 				return -EROFS;
3935 			}
3936 			ext4_msg(sb, KERN_INFO, "write access will "
3937 			       "be enabled during recovery");
3938 		}
3939 	}
3940 
3941 	if (journal_inum && journal_dev) {
3942 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3943 		       "and inode journals!");
3944 		return -EINVAL;
3945 	}
3946 
3947 	if (journal_inum) {
3948 		if (!(journal = ext4_get_journal(sb, journal_inum)))
3949 			return -EINVAL;
3950 	} else {
3951 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3952 			return -EINVAL;
3953 	}
3954 
3955 	if (!(journal->j_flags & JBD2_BARRIER))
3956 		ext4_msg(sb, KERN_INFO, "barriers disabled");
3957 
3958 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3959 		err = jbd2_journal_wipe(journal, !really_read_only);
3960 	if (!err) {
3961 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
3962 		if (save)
3963 			memcpy(save, ((char *) es) +
3964 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
3965 		err = jbd2_journal_load(journal);
3966 		if (save)
3967 			memcpy(((char *) es) + EXT4_S_ERR_START,
3968 			       save, EXT4_S_ERR_LEN);
3969 		kfree(save);
3970 	}
3971 
3972 	if (err) {
3973 		ext4_msg(sb, KERN_ERR, "error loading journal");
3974 		jbd2_journal_destroy(journal);
3975 		return err;
3976 	}
3977 
3978 	EXT4_SB(sb)->s_journal = journal;
3979 	ext4_clear_journal_err(sb, es);
3980 
3981 	if (!really_read_only && journal_devnum &&
3982 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3983 		es->s_journal_dev = cpu_to_le32(journal_devnum);
3984 
3985 		/* Make sure we flush the recovery flag to disk. */
3986 		ext4_commit_super(sb, 1);
3987 	}
3988 
3989 	return 0;
3990 }
3991 
3992 static int ext4_commit_super(struct super_block *sb, int sync)
3993 {
3994 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3995 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3996 	int error = 0;
3997 
3998 	if (!sbh || block_device_ejected(sb))
3999 		return error;
4000 	if (buffer_write_io_error(sbh)) {
4001 		/*
4002 		 * Oh, dear.  A previous attempt to write the
4003 		 * superblock failed.  This could happen because the
4004 		 * USB device was yanked out.  Or it could happen to
4005 		 * be a transient write error and maybe the block will
4006 		 * be remapped.  Nothing we can do but to retry the
4007 		 * write and hope for the best.
4008 		 */
4009 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4010 		       "superblock detected");
4011 		clear_buffer_write_io_error(sbh);
4012 		set_buffer_uptodate(sbh);
4013 	}
4014 	/*
4015 	 * If the file system is mounted read-only, don't update the
4016 	 * superblock write time.  This avoids updating the superblock
4017 	 * write time when we are mounting the root file system
4018 	 * read/only but we need to replay the journal; at that point,
4019 	 * for people who are east of GMT and who make their clock
4020 	 * tick in localtime for Windows bug-for-bug compatibility,
4021 	 * the clock is set in the future, and this will cause e2fsck
4022 	 * to complain and force a full file system check.
4023 	 */
4024 	if (!(sb->s_flags & MS_RDONLY))
4025 		es->s_wtime = cpu_to_le32(get_seconds());
4026 	if (sb->s_bdev->bd_part)
4027 		es->s_kbytes_written =
4028 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4029 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4030 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4031 	else
4032 		es->s_kbytes_written =
4033 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4034 	ext4_free_blocks_count_set(es,
4035 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4036 				&EXT4_SB(sb)->s_freeclusters_counter)));
4037 	es->s_free_inodes_count =
4038 		cpu_to_le32(percpu_counter_sum_positive(
4039 				&EXT4_SB(sb)->s_freeinodes_counter));
4040 	sb->s_dirt = 0;
4041 	BUFFER_TRACE(sbh, "marking dirty");
4042 	mark_buffer_dirty(sbh);
4043 	if (sync) {
4044 		error = sync_dirty_buffer(sbh);
4045 		if (error)
4046 			return error;
4047 
4048 		error = buffer_write_io_error(sbh);
4049 		if (error) {
4050 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4051 			       "superblock");
4052 			clear_buffer_write_io_error(sbh);
4053 			set_buffer_uptodate(sbh);
4054 		}
4055 	}
4056 	return error;
4057 }
4058 
4059 /*
4060  * Have we just finished recovery?  If so, and if we are mounting (or
4061  * remounting) the filesystem readonly, then we will end up with a
4062  * consistent fs on disk.  Record that fact.
4063  */
4064 static void ext4_mark_recovery_complete(struct super_block *sb,
4065 					struct ext4_super_block *es)
4066 {
4067 	journal_t *journal = EXT4_SB(sb)->s_journal;
4068 
4069 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4070 		BUG_ON(journal != NULL);
4071 		return;
4072 	}
4073 	jbd2_journal_lock_updates(journal);
4074 	if (jbd2_journal_flush(journal) < 0)
4075 		goto out;
4076 
4077 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4078 	    sb->s_flags & MS_RDONLY) {
4079 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4080 		ext4_commit_super(sb, 1);
4081 	}
4082 
4083 out:
4084 	jbd2_journal_unlock_updates(journal);
4085 }
4086 
4087 /*
4088  * If we are mounting (or read-write remounting) a filesystem whose journal
4089  * has recorded an error from a previous lifetime, move that error to the
4090  * main filesystem now.
4091  */
4092 static void ext4_clear_journal_err(struct super_block *sb,
4093 				   struct ext4_super_block *es)
4094 {
4095 	journal_t *journal;
4096 	int j_errno;
4097 	const char *errstr;
4098 
4099 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4100 
4101 	journal = EXT4_SB(sb)->s_journal;
4102 
4103 	/*
4104 	 * Now check for any error status which may have been recorded in the
4105 	 * journal by a prior ext4_error() or ext4_abort()
4106 	 */
4107 
4108 	j_errno = jbd2_journal_errno(journal);
4109 	if (j_errno) {
4110 		char nbuf[16];
4111 
4112 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4113 		ext4_warning(sb, "Filesystem error recorded "
4114 			     "from previous mount: %s", errstr);
4115 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4116 
4117 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4118 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4119 		ext4_commit_super(sb, 1);
4120 
4121 		jbd2_journal_clear_err(journal);
4122 	}
4123 }
4124 
4125 /*
4126  * Force the running and committing transactions to commit,
4127  * and wait on the commit.
4128  */
4129 int ext4_force_commit(struct super_block *sb)
4130 {
4131 	journal_t *journal;
4132 	int ret = 0;
4133 
4134 	if (sb->s_flags & MS_RDONLY)
4135 		return 0;
4136 
4137 	journal = EXT4_SB(sb)->s_journal;
4138 	if (journal) {
4139 		vfs_check_frozen(sb, SB_FREEZE_TRANS);
4140 		ret = ext4_journal_force_commit(journal);
4141 	}
4142 
4143 	return ret;
4144 }
4145 
4146 static void ext4_write_super(struct super_block *sb)
4147 {
4148 	lock_super(sb);
4149 	ext4_commit_super(sb, 1);
4150 	unlock_super(sb);
4151 }
4152 
4153 static int ext4_sync_fs(struct super_block *sb, int wait)
4154 {
4155 	int ret = 0;
4156 	tid_t target;
4157 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4158 
4159 	trace_ext4_sync_fs(sb, wait);
4160 	flush_workqueue(sbi->dio_unwritten_wq);
4161 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4162 		if (wait)
4163 			jbd2_log_wait_commit(sbi->s_journal, target);
4164 	}
4165 	return ret;
4166 }
4167 
4168 /*
4169  * LVM calls this function before a (read-only) snapshot is created.  This
4170  * gives us a chance to flush the journal completely and mark the fs clean.
4171  *
4172  * Note that only this function cannot bring a filesystem to be in a clean
4173  * state independently, because ext4 prevents a new handle from being started
4174  * by @sb->s_frozen, which stays in an upper layer.  It thus needs help from
4175  * the upper layer.
4176  */
4177 static int ext4_freeze(struct super_block *sb)
4178 {
4179 	int error = 0;
4180 	journal_t *journal;
4181 
4182 	if (sb->s_flags & MS_RDONLY)
4183 		return 0;
4184 
4185 	journal = EXT4_SB(sb)->s_journal;
4186 
4187 	/* Now we set up the journal barrier. */
4188 	jbd2_journal_lock_updates(journal);
4189 
4190 	/*
4191 	 * Don't clear the needs_recovery flag if we failed to flush
4192 	 * the journal.
4193 	 */
4194 	error = jbd2_journal_flush(journal);
4195 	if (error < 0)
4196 		goto out;
4197 
4198 	/* Journal blocked and flushed, clear needs_recovery flag. */
4199 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4200 	error = ext4_commit_super(sb, 1);
4201 out:
4202 	/* we rely on s_frozen to stop further updates */
4203 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4204 	return error;
4205 }
4206 
4207 /*
4208  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4209  * flag here, even though the filesystem is not technically dirty yet.
4210  */
4211 static int ext4_unfreeze(struct super_block *sb)
4212 {
4213 	if (sb->s_flags & MS_RDONLY)
4214 		return 0;
4215 
4216 	lock_super(sb);
4217 	/* Reset the needs_recovery flag before the fs is unlocked. */
4218 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4219 	ext4_commit_super(sb, 1);
4220 	unlock_super(sb);
4221 	return 0;
4222 }
4223 
4224 /*
4225  * Structure to save mount options for ext4_remount's benefit
4226  */
4227 struct ext4_mount_options {
4228 	unsigned long s_mount_opt;
4229 	unsigned long s_mount_opt2;
4230 	kuid_t s_resuid;
4231 	kgid_t s_resgid;
4232 	unsigned long s_commit_interval;
4233 	u32 s_min_batch_time, s_max_batch_time;
4234 #ifdef CONFIG_QUOTA
4235 	int s_jquota_fmt;
4236 	char *s_qf_names[MAXQUOTAS];
4237 #endif
4238 };
4239 
4240 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4241 {
4242 	struct ext4_super_block *es;
4243 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4244 	unsigned long old_sb_flags;
4245 	struct ext4_mount_options old_opts;
4246 	int enable_quota = 0;
4247 	ext4_group_t g;
4248 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4249 	int err = 0;
4250 #ifdef CONFIG_QUOTA
4251 	int i;
4252 #endif
4253 	char *orig_data = kstrdup(data, GFP_KERNEL);
4254 
4255 	/* Store the original options */
4256 	lock_super(sb);
4257 	old_sb_flags = sb->s_flags;
4258 	old_opts.s_mount_opt = sbi->s_mount_opt;
4259 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4260 	old_opts.s_resuid = sbi->s_resuid;
4261 	old_opts.s_resgid = sbi->s_resgid;
4262 	old_opts.s_commit_interval = sbi->s_commit_interval;
4263 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4264 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4265 #ifdef CONFIG_QUOTA
4266 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4267 	for (i = 0; i < MAXQUOTAS; i++)
4268 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4269 #endif
4270 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4271 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4272 
4273 	/*
4274 	 * Allow the "check" option to be passed as a remount option.
4275 	 */
4276 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4277 		err = -EINVAL;
4278 		goto restore_opts;
4279 	}
4280 
4281 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4282 		ext4_abort(sb, "Abort forced by user");
4283 
4284 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4285 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4286 
4287 	es = sbi->s_es;
4288 
4289 	if (sbi->s_journal) {
4290 		ext4_init_journal_params(sb, sbi->s_journal);
4291 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4292 	}
4293 
4294 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4295 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4296 			err = -EROFS;
4297 			goto restore_opts;
4298 		}
4299 
4300 		if (*flags & MS_RDONLY) {
4301 			err = dquot_suspend(sb, -1);
4302 			if (err < 0)
4303 				goto restore_opts;
4304 
4305 			/*
4306 			 * First of all, the unconditional stuff we have to do
4307 			 * to disable replay of the journal when we next remount
4308 			 */
4309 			sb->s_flags |= MS_RDONLY;
4310 
4311 			/*
4312 			 * OK, test if we are remounting a valid rw partition
4313 			 * readonly, and if so set the rdonly flag and then
4314 			 * mark the partition as valid again.
4315 			 */
4316 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4317 			    (sbi->s_mount_state & EXT4_VALID_FS))
4318 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4319 
4320 			if (sbi->s_journal)
4321 				ext4_mark_recovery_complete(sb, es);
4322 		} else {
4323 			/* Make sure we can mount this feature set readwrite */
4324 			if (!ext4_feature_set_ok(sb, 0)) {
4325 				err = -EROFS;
4326 				goto restore_opts;
4327 			}
4328 			/*
4329 			 * Make sure the group descriptor checksums
4330 			 * are sane.  If they aren't, refuse to remount r/w.
4331 			 */
4332 			for (g = 0; g < sbi->s_groups_count; g++) {
4333 				struct ext4_group_desc *gdp =
4334 					ext4_get_group_desc(sb, g, NULL);
4335 
4336 				if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
4337 					ext4_msg(sb, KERN_ERR,
4338 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4339 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4340 					       le16_to_cpu(gdp->bg_checksum));
4341 					err = -EINVAL;
4342 					goto restore_opts;
4343 				}
4344 			}
4345 
4346 			/*
4347 			 * If we have an unprocessed orphan list hanging
4348 			 * around from a previously readonly bdev mount,
4349 			 * require a full umount/remount for now.
4350 			 */
4351 			if (es->s_last_orphan) {
4352 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4353 				       "remount RDWR because of unprocessed "
4354 				       "orphan inode list.  Please "
4355 				       "umount/remount instead");
4356 				err = -EINVAL;
4357 				goto restore_opts;
4358 			}
4359 
4360 			/*
4361 			 * Mounting a RDONLY partition read-write, so reread
4362 			 * and store the current valid flag.  (It may have
4363 			 * been changed by e2fsck since we originally mounted
4364 			 * the partition.)
4365 			 */
4366 			if (sbi->s_journal)
4367 				ext4_clear_journal_err(sb, es);
4368 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4369 			if (!ext4_setup_super(sb, es, 0))
4370 				sb->s_flags &= ~MS_RDONLY;
4371 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4372 						     EXT4_FEATURE_INCOMPAT_MMP))
4373 				if (ext4_multi_mount_protect(sb,
4374 						le64_to_cpu(es->s_mmp_block))) {
4375 					err = -EROFS;
4376 					goto restore_opts;
4377 				}
4378 			enable_quota = 1;
4379 		}
4380 	}
4381 
4382 	/*
4383 	 * Reinitialize lazy itable initialization thread based on
4384 	 * current settings
4385 	 */
4386 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4387 		ext4_unregister_li_request(sb);
4388 	else {
4389 		ext4_group_t first_not_zeroed;
4390 		first_not_zeroed = ext4_has_uninit_itable(sb);
4391 		ext4_register_li_request(sb, first_not_zeroed);
4392 	}
4393 
4394 	ext4_setup_system_zone(sb);
4395 	if (sbi->s_journal == NULL)
4396 		ext4_commit_super(sb, 1);
4397 
4398 #ifdef CONFIG_QUOTA
4399 	/* Release old quota file names */
4400 	for (i = 0; i < MAXQUOTAS; i++)
4401 		if (old_opts.s_qf_names[i] &&
4402 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4403 			kfree(old_opts.s_qf_names[i]);
4404 #endif
4405 	unlock_super(sb);
4406 	if (enable_quota)
4407 		dquot_resume(sb, -1);
4408 
4409 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4410 	kfree(orig_data);
4411 	return 0;
4412 
4413 restore_opts:
4414 	sb->s_flags = old_sb_flags;
4415 	sbi->s_mount_opt = old_opts.s_mount_opt;
4416 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4417 	sbi->s_resuid = old_opts.s_resuid;
4418 	sbi->s_resgid = old_opts.s_resgid;
4419 	sbi->s_commit_interval = old_opts.s_commit_interval;
4420 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4421 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4422 #ifdef CONFIG_QUOTA
4423 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4424 	for (i = 0; i < MAXQUOTAS; i++) {
4425 		if (sbi->s_qf_names[i] &&
4426 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4427 			kfree(sbi->s_qf_names[i]);
4428 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4429 	}
4430 #endif
4431 	unlock_super(sb);
4432 	kfree(orig_data);
4433 	return err;
4434 }
4435 
4436 /*
4437  * Note: calculating the overhead so we can be compatible with
4438  * historical BSD practice is quite difficult in the face of
4439  * clusters/bigalloc.  This is because multiple metadata blocks from
4440  * different block group can end up in the same allocation cluster.
4441  * Calculating the exact overhead in the face of clustered allocation
4442  * requires either O(all block bitmaps) in memory or O(number of block
4443  * groups**2) in time.  We will still calculate the superblock for
4444  * older file systems --- and if we come across with a bigalloc file
4445  * system with zero in s_overhead_clusters the estimate will be close to
4446  * correct especially for very large cluster sizes --- but for newer
4447  * file systems, it's better to calculate this figure once at mkfs
4448  * time, and store it in the superblock.  If the superblock value is
4449  * present (even for non-bigalloc file systems), we will use it.
4450  */
4451 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4452 {
4453 	struct super_block *sb = dentry->d_sb;
4454 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4455 	struct ext4_super_block *es = sbi->s_es;
4456 	struct ext4_group_desc *gdp;
4457 	u64 fsid;
4458 	s64 bfree;
4459 
4460 	if (test_opt(sb, MINIX_DF)) {
4461 		sbi->s_overhead_last = 0;
4462 	} else if (es->s_overhead_clusters) {
4463 		sbi->s_overhead_last = le32_to_cpu(es->s_overhead_clusters);
4464 	} else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
4465 		ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4466 		ext4_fsblk_t overhead = 0;
4467 
4468 		/*
4469 		 * Compute the overhead (FS structures).  This is constant
4470 		 * for a given filesystem unless the number of block groups
4471 		 * changes so we cache the previous value until it does.
4472 		 */
4473 
4474 		/*
4475 		 * All of the blocks before first_data_block are
4476 		 * overhead
4477 		 */
4478 		overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4479 
4480 		/*
4481 		 * Add the overhead found in each block group
4482 		 */
4483 		for (i = 0; i < ngroups; i++) {
4484 			gdp = ext4_get_group_desc(sb, i, NULL);
4485 			overhead += ext4_num_overhead_clusters(sb, i, gdp);
4486 			cond_resched();
4487 		}
4488 		sbi->s_overhead_last = overhead;
4489 		smp_wmb();
4490 		sbi->s_blocks_last = ext4_blocks_count(es);
4491 	}
4492 
4493 	buf->f_type = EXT4_SUPER_MAGIC;
4494 	buf->f_bsize = sb->s_blocksize;
4495 	buf->f_blocks = (ext4_blocks_count(es) -
4496 			 EXT4_C2B(sbi, sbi->s_overhead_last));
4497 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4498 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4499 	/* prevent underflow in case that few free space is available */
4500 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4501 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4502 	if (buf->f_bfree < ext4_r_blocks_count(es))
4503 		buf->f_bavail = 0;
4504 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4505 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4506 	buf->f_namelen = EXT4_NAME_LEN;
4507 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4508 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4509 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4510 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4511 
4512 	return 0;
4513 }
4514 
4515 /* Helper function for writing quotas on sync - we need to start transaction
4516  * before quota file is locked for write. Otherwise the are possible deadlocks:
4517  * Process 1                         Process 2
4518  * ext4_create()                     quota_sync()
4519  *   jbd2_journal_start()                  write_dquot()
4520  *   dquot_initialize()                         down(dqio_mutex)
4521  *     down(dqio_mutex)                    jbd2_journal_start()
4522  *
4523  */
4524 
4525 #ifdef CONFIG_QUOTA
4526 
4527 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4528 {
4529 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4530 }
4531 
4532 static int ext4_write_dquot(struct dquot *dquot)
4533 {
4534 	int ret, err;
4535 	handle_t *handle;
4536 	struct inode *inode;
4537 
4538 	inode = dquot_to_inode(dquot);
4539 	handle = ext4_journal_start(inode,
4540 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4541 	if (IS_ERR(handle))
4542 		return PTR_ERR(handle);
4543 	ret = dquot_commit(dquot);
4544 	err = ext4_journal_stop(handle);
4545 	if (!ret)
4546 		ret = err;
4547 	return ret;
4548 }
4549 
4550 static int ext4_acquire_dquot(struct dquot *dquot)
4551 {
4552 	int ret, err;
4553 	handle_t *handle;
4554 
4555 	handle = ext4_journal_start(dquot_to_inode(dquot),
4556 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4557 	if (IS_ERR(handle))
4558 		return PTR_ERR(handle);
4559 	ret = dquot_acquire(dquot);
4560 	err = ext4_journal_stop(handle);
4561 	if (!ret)
4562 		ret = err;
4563 	return ret;
4564 }
4565 
4566 static int ext4_release_dquot(struct dquot *dquot)
4567 {
4568 	int ret, err;
4569 	handle_t *handle;
4570 
4571 	handle = ext4_journal_start(dquot_to_inode(dquot),
4572 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4573 	if (IS_ERR(handle)) {
4574 		/* Release dquot anyway to avoid endless cycle in dqput() */
4575 		dquot_release(dquot);
4576 		return PTR_ERR(handle);
4577 	}
4578 	ret = dquot_release(dquot);
4579 	err = ext4_journal_stop(handle);
4580 	if (!ret)
4581 		ret = err;
4582 	return ret;
4583 }
4584 
4585 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4586 {
4587 	/* Are we journaling quotas? */
4588 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4589 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4590 		dquot_mark_dquot_dirty(dquot);
4591 		return ext4_write_dquot(dquot);
4592 	} else {
4593 		return dquot_mark_dquot_dirty(dquot);
4594 	}
4595 }
4596 
4597 static int ext4_write_info(struct super_block *sb, int type)
4598 {
4599 	int ret, err;
4600 	handle_t *handle;
4601 
4602 	/* Data block + inode block */
4603 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
4604 	if (IS_ERR(handle))
4605 		return PTR_ERR(handle);
4606 	ret = dquot_commit_info(sb, type);
4607 	err = ext4_journal_stop(handle);
4608 	if (!ret)
4609 		ret = err;
4610 	return ret;
4611 }
4612 
4613 /*
4614  * Turn on quotas during mount time - we need to find
4615  * the quota file and such...
4616  */
4617 static int ext4_quota_on_mount(struct super_block *sb, int type)
4618 {
4619 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4620 					EXT4_SB(sb)->s_jquota_fmt, type);
4621 }
4622 
4623 /*
4624  * Standard function to be called on quota_on
4625  */
4626 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4627 			 struct path *path)
4628 {
4629 	int err;
4630 
4631 	if (!test_opt(sb, QUOTA))
4632 		return -EINVAL;
4633 
4634 	/* Quotafile not on the same filesystem? */
4635 	if (path->dentry->d_sb != sb)
4636 		return -EXDEV;
4637 	/* Journaling quota? */
4638 	if (EXT4_SB(sb)->s_qf_names[type]) {
4639 		/* Quotafile not in fs root? */
4640 		if (path->dentry->d_parent != sb->s_root)
4641 			ext4_msg(sb, KERN_WARNING,
4642 				"Quota file not on filesystem root. "
4643 				"Journaled quota will not work");
4644 	}
4645 
4646 	/*
4647 	 * When we journal data on quota file, we have to flush journal to see
4648 	 * all updates to the file when we bypass pagecache...
4649 	 */
4650 	if (EXT4_SB(sb)->s_journal &&
4651 	    ext4_should_journal_data(path->dentry->d_inode)) {
4652 		/*
4653 		 * We don't need to lock updates but journal_flush() could
4654 		 * otherwise be livelocked...
4655 		 */
4656 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4657 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4658 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4659 		if (err)
4660 			return err;
4661 	}
4662 
4663 	return dquot_quota_on(sb, type, format_id, path);
4664 }
4665 
4666 static int ext4_quota_off(struct super_block *sb, int type)
4667 {
4668 	struct inode *inode = sb_dqopt(sb)->files[type];
4669 	handle_t *handle;
4670 
4671 	/* Force all delayed allocation blocks to be allocated.
4672 	 * Caller already holds s_umount sem */
4673 	if (test_opt(sb, DELALLOC))
4674 		sync_filesystem(sb);
4675 
4676 	if (!inode)
4677 		goto out;
4678 
4679 	/* Update modification times of quota files when userspace can
4680 	 * start looking at them */
4681 	handle = ext4_journal_start(inode, 1);
4682 	if (IS_ERR(handle))
4683 		goto out;
4684 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4685 	ext4_mark_inode_dirty(handle, inode);
4686 	ext4_journal_stop(handle);
4687 
4688 out:
4689 	return dquot_quota_off(sb, type);
4690 }
4691 
4692 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4693  * acquiring the locks... As quota files are never truncated and quota code
4694  * itself serializes the operations (and no one else should touch the files)
4695  * we don't have to be afraid of races */
4696 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4697 			       size_t len, loff_t off)
4698 {
4699 	struct inode *inode = sb_dqopt(sb)->files[type];
4700 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4701 	int err = 0;
4702 	int offset = off & (sb->s_blocksize - 1);
4703 	int tocopy;
4704 	size_t toread;
4705 	struct buffer_head *bh;
4706 	loff_t i_size = i_size_read(inode);
4707 
4708 	if (off > i_size)
4709 		return 0;
4710 	if (off+len > i_size)
4711 		len = i_size-off;
4712 	toread = len;
4713 	while (toread > 0) {
4714 		tocopy = sb->s_blocksize - offset < toread ?
4715 				sb->s_blocksize - offset : toread;
4716 		bh = ext4_bread(NULL, inode, blk, 0, &err);
4717 		if (err)
4718 			return err;
4719 		if (!bh)	/* A hole? */
4720 			memset(data, 0, tocopy);
4721 		else
4722 			memcpy(data, bh->b_data+offset, tocopy);
4723 		brelse(bh);
4724 		offset = 0;
4725 		toread -= tocopy;
4726 		data += tocopy;
4727 		blk++;
4728 	}
4729 	return len;
4730 }
4731 
4732 /* Write to quotafile (we know the transaction is already started and has
4733  * enough credits) */
4734 static ssize_t ext4_quota_write(struct super_block *sb, int type,
4735 				const char *data, size_t len, loff_t off)
4736 {
4737 	struct inode *inode = sb_dqopt(sb)->files[type];
4738 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4739 	int err = 0;
4740 	int offset = off & (sb->s_blocksize - 1);
4741 	struct buffer_head *bh;
4742 	handle_t *handle = journal_current_handle();
4743 
4744 	if (EXT4_SB(sb)->s_journal && !handle) {
4745 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4746 			" cancelled because transaction is not started",
4747 			(unsigned long long)off, (unsigned long long)len);
4748 		return -EIO;
4749 	}
4750 	/*
4751 	 * Since we account only one data block in transaction credits,
4752 	 * then it is impossible to cross a block boundary.
4753 	 */
4754 	if (sb->s_blocksize - offset < len) {
4755 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4756 			" cancelled because not block aligned",
4757 			(unsigned long long)off, (unsigned long long)len);
4758 		return -EIO;
4759 	}
4760 
4761 	bh = ext4_bread(handle, inode, blk, 1, &err);
4762 	if (!bh)
4763 		goto out;
4764 	err = ext4_journal_get_write_access(handle, bh);
4765 	if (err) {
4766 		brelse(bh);
4767 		goto out;
4768 	}
4769 	lock_buffer(bh);
4770 	memcpy(bh->b_data+offset, data, len);
4771 	flush_dcache_page(bh->b_page);
4772 	unlock_buffer(bh);
4773 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
4774 	brelse(bh);
4775 out:
4776 	if (err)
4777 		return err;
4778 	if (inode->i_size < off + len) {
4779 		i_size_write(inode, off + len);
4780 		EXT4_I(inode)->i_disksize = inode->i_size;
4781 		ext4_mark_inode_dirty(handle, inode);
4782 	}
4783 	return len;
4784 }
4785 
4786 #endif
4787 
4788 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
4789 		       const char *dev_name, void *data)
4790 {
4791 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
4792 }
4793 
4794 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4795 static inline void register_as_ext2(void)
4796 {
4797 	int err = register_filesystem(&ext2_fs_type);
4798 	if (err)
4799 		printk(KERN_WARNING
4800 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4801 }
4802 
4803 static inline void unregister_as_ext2(void)
4804 {
4805 	unregister_filesystem(&ext2_fs_type);
4806 }
4807 
4808 static inline int ext2_feature_set_ok(struct super_block *sb)
4809 {
4810 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
4811 		return 0;
4812 	if (sb->s_flags & MS_RDONLY)
4813 		return 1;
4814 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
4815 		return 0;
4816 	return 1;
4817 }
4818 MODULE_ALIAS("ext2");
4819 #else
4820 static inline void register_as_ext2(void) { }
4821 static inline void unregister_as_ext2(void) { }
4822 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
4823 #endif
4824 
4825 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4826 static inline void register_as_ext3(void)
4827 {
4828 	int err = register_filesystem(&ext3_fs_type);
4829 	if (err)
4830 		printk(KERN_WARNING
4831 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4832 }
4833 
4834 static inline void unregister_as_ext3(void)
4835 {
4836 	unregister_filesystem(&ext3_fs_type);
4837 }
4838 
4839 static inline int ext3_feature_set_ok(struct super_block *sb)
4840 {
4841 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
4842 		return 0;
4843 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
4844 		return 0;
4845 	if (sb->s_flags & MS_RDONLY)
4846 		return 1;
4847 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
4848 		return 0;
4849 	return 1;
4850 }
4851 MODULE_ALIAS("ext3");
4852 #else
4853 static inline void register_as_ext3(void) { }
4854 static inline void unregister_as_ext3(void) { }
4855 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
4856 #endif
4857 
4858 static struct file_system_type ext4_fs_type = {
4859 	.owner		= THIS_MODULE,
4860 	.name		= "ext4",
4861 	.mount		= ext4_mount,
4862 	.kill_sb	= kill_block_super,
4863 	.fs_flags	= FS_REQUIRES_DEV,
4864 };
4865 
4866 static int __init ext4_init_feat_adverts(void)
4867 {
4868 	struct ext4_features *ef;
4869 	int ret = -ENOMEM;
4870 
4871 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
4872 	if (!ef)
4873 		goto out;
4874 
4875 	ef->f_kobj.kset = ext4_kset;
4876 	init_completion(&ef->f_kobj_unregister);
4877 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
4878 				   "features");
4879 	if (ret) {
4880 		kfree(ef);
4881 		goto out;
4882 	}
4883 
4884 	ext4_feat = ef;
4885 	ret = 0;
4886 out:
4887 	return ret;
4888 }
4889 
4890 static void ext4_exit_feat_adverts(void)
4891 {
4892 	kobject_put(&ext4_feat->f_kobj);
4893 	wait_for_completion(&ext4_feat->f_kobj_unregister);
4894 	kfree(ext4_feat);
4895 }
4896 
4897 /* Shared across all ext4 file systems */
4898 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
4899 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
4900 
4901 static int __init ext4_init_fs(void)
4902 {
4903 	int i, err;
4904 
4905 	ext4_li_info = NULL;
4906 	mutex_init(&ext4_li_mtx);
4907 
4908 	ext4_check_flag_values();
4909 
4910 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
4911 		mutex_init(&ext4__aio_mutex[i]);
4912 		init_waitqueue_head(&ext4__ioend_wq[i]);
4913 	}
4914 
4915 	err = ext4_init_pageio();
4916 	if (err)
4917 		return err;
4918 	err = ext4_init_system_zone();
4919 	if (err)
4920 		goto out6;
4921 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
4922 	if (!ext4_kset)
4923 		goto out5;
4924 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
4925 
4926 	err = ext4_init_feat_adverts();
4927 	if (err)
4928 		goto out4;
4929 
4930 	err = ext4_init_mballoc();
4931 	if (err)
4932 		goto out3;
4933 
4934 	err = ext4_init_xattr();
4935 	if (err)
4936 		goto out2;
4937 	err = init_inodecache();
4938 	if (err)
4939 		goto out1;
4940 	register_as_ext3();
4941 	register_as_ext2();
4942 	err = register_filesystem(&ext4_fs_type);
4943 	if (err)
4944 		goto out;
4945 
4946 	return 0;
4947 out:
4948 	unregister_as_ext2();
4949 	unregister_as_ext3();
4950 	destroy_inodecache();
4951 out1:
4952 	ext4_exit_xattr();
4953 out2:
4954 	ext4_exit_mballoc();
4955 out3:
4956 	ext4_exit_feat_adverts();
4957 out4:
4958 	if (ext4_proc_root)
4959 		remove_proc_entry("fs/ext4", NULL);
4960 	kset_unregister(ext4_kset);
4961 out5:
4962 	ext4_exit_system_zone();
4963 out6:
4964 	ext4_exit_pageio();
4965 	return err;
4966 }
4967 
4968 static void __exit ext4_exit_fs(void)
4969 {
4970 	ext4_destroy_lazyinit_thread();
4971 	unregister_as_ext2();
4972 	unregister_as_ext3();
4973 	unregister_filesystem(&ext4_fs_type);
4974 	destroy_inodecache();
4975 	ext4_exit_xattr();
4976 	ext4_exit_mballoc();
4977 	ext4_exit_feat_adverts();
4978 	remove_proc_entry("fs/ext4", NULL);
4979 	kset_unregister(ext4_kset);
4980 	ext4_exit_system_zone();
4981 	ext4_exit_pageio();
4982 }
4983 
4984 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4985 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4986 MODULE_LICENSE("GPL");
4987 module_init(ext4_init_fs)
4988 module_exit(ext4_exit_fs)
4989