xref: /openbmc/linux/fs/ext4/super.c (revision 63dc02bd)
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 	end_writeback(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 	int arg = 0;
1452 
1453 #ifdef CONFIG_QUOTA
1454 	if (token == Opt_usrjquota)
1455 		return set_qf_name(sb, USRQUOTA, &args[0]);
1456 	else if (token == Opt_grpjquota)
1457 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1458 	else if (token == Opt_offusrjquota)
1459 		return clear_qf_name(sb, USRQUOTA);
1460 	else if (token == Opt_offgrpjquota)
1461 		return clear_qf_name(sb, GRPQUOTA);
1462 #endif
1463 	if (args->from && match_int(args, &arg))
1464 		return -1;
1465 	switch (token) {
1466 	case Opt_noacl:
1467 	case Opt_nouser_xattr:
1468 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1469 		break;
1470 	case Opt_sb:
1471 		return 1;	/* handled by get_sb_block() */
1472 	case Opt_removed:
1473 		ext4_msg(sb, KERN_WARNING,
1474 			 "Ignoring removed %s option", opt);
1475 		return 1;
1476 	case Opt_resuid:
1477 		sbi->s_resuid = arg;
1478 		return 1;
1479 	case Opt_resgid:
1480 		sbi->s_resgid = arg;
1481 		return 1;
1482 	case Opt_abort:
1483 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1484 		return 1;
1485 	case Opt_i_version:
1486 		sb->s_flags |= MS_I_VERSION;
1487 		return 1;
1488 	case Opt_journal_dev:
1489 		if (is_remount) {
1490 			ext4_msg(sb, KERN_ERR,
1491 				 "Cannot specify journal on remount");
1492 			return -1;
1493 		}
1494 		*journal_devnum = arg;
1495 		return 1;
1496 	case Opt_journal_ioprio:
1497 		if (arg < 0 || arg > 7)
1498 			return -1;
1499 		*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1500 		return 1;
1501 	}
1502 
1503 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1504 		if (token != m->token)
1505 			continue;
1506 		if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1507 			return -1;
1508 		if (m->flags & MOPT_EXPLICIT)
1509 			set_opt2(sb, EXPLICIT_DELALLOC);
1510 		if (m->flags & MOPT_CLEAR_ERR)
1511 			clear_opt(sb, ERRORS_MASK);
1512 		if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1513 			ext4_msg(sb, KERN_ERR, "Cannot change quota "
1514 				 "options when quota turned on");
1515 			return -1;
1516 		}
1517 
1518 		if (m->flags & MOPT_NOSUPPORT) {
1519 			ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1520 		} else if (token == Opt_commit) {
1521 			if (arg == 0)
1522 				arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1523 			sbi->s_commit_interval = HZ * arg;
1524 		} else if (token == Opt_max_batch_time) {
1525 			if (arg == 0)
1526 				arg = EXT4_DEF_MAX_BATCH_TIME;
1527 			sbi->s_max_batch_time = arg;
1528 		} else if (token == Opt_min_batch_time) {
1529 			sbi->s_min_batch_time = arg;
1530 		} else if (token == Opt_inode_readahead_blks) {
1531 			if (arg > (1 << 30))
1532 				return -1;
1533 			if (arg && !is_power_of_2(arg)) {
1534 				ext4_msg(sb, KERN_ERR,
1535 					 "EXT4-fs: inode_readahead_blks"
1536 					 " must be a power of 2");
1537 				return -1;
1538 			}
1539 			sbi->s_inode_readahead_blks = arg;
1540 		} else if (token == Opt_init_itable) {
1541 			set_opt(sb, INIT_INODE_TABLE);
1542 			if (!args->from)
1543 				arg = EXT4_DEF_LI_WAIT_MULT;
1544 			sbi->s_li_wait_mult = arg;
1545 		} else if (token == Opt_stripe) {
1546 			sbi->s_stripe = arg;
1547 		} else if (m->flags & MOPT_DATAJ) {
1548 			if (is_remount) {
1549 				if (!sbi->s_journal)
1550 					ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1551 				else if (test_opt(sb, DATA_FLAGS) !=
1552 					 m->mount_opt) {
1553 					ext4_msg(sb, KERN_ERR,
1554 					 "Cannot change data mode on remount");
1555 					return -1;
1556 				}
1557 			} else {
1558 				clear_opt(sb, DATA_FLAGS);
1559 				sbi->s_mount_opt |= m->mount_opt;
1560 			}
1561 #ifdef CONFIG_QUOTA
1562 		} else if (m->flags & MOPT_QFMT) {
1563 			if (sb_any_quota_loaded(sb) &&
1564 			    sbi->s_jquota_fmt != m->mount_opt) {
1565 				ext4_msg(sb, KERN_ERR, "Cannot "
1566 					 "change journaled quota options "
1567 					 "when quota turned on");
1568 				return -1;
1569 			}
1570 			sbi->s_jquota_fmt = m->mount_opt;
1571 #endif
1572 		} else {
1573 			if (!args->from)
1574 				arg = 1;
1575 			if (m->flags & MOPT_CLEAR)
1576 				arg = !arg;
1577 			else if (unlikely(!(m->flags & MOPT_SET))) {
1578 				ext4_msg(sb, KERN_WARNING,
1579 					 "buggy handling of option %s", opt);
1580 				WARN_ON(1);
1581 				return -1;
1582 			}
1583 			if (arg != 0)
1584 				sbi->s_mount_opt |= m->mount_opt;
1585 			else
1586 				sbi->s_mount_opt &= ~m->mount_opt;
1587 		}
1588 		return 1;
1589 	}
1590 	ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1591 		 "or missing value", opt);
1592 	return -1;
1593 }
1594 
1595 static int parse_options(char *options, struct super_block *sb,
1596 			 unsigned long *journal_devnum,
1597 			 unsigned int *journal_ioprio,
1598 			 int is_remount)
1599 {
1600 #ifdef CONFIG_QUOTA
1601 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1602 #endif
1603 	char *p;
1604 	substring_t args[MAX_OPT_ARGS];
1605 	int token;
1606 
1607 	if (!options)
1608 		return 1;
1609 
1610 	while ((p = strsep(&options, ",")) != NULL) {
1611 		if (!*p)
1612 			continue;
1613 		/*
1614 		 * Initialize args struct so we know whether arg was
1615 		 * found; some options take optional arguments.
1616 		 */
1617 		args[0].to = args[0].from = 0;
1618 		token = match_token(p, tokens, args);
1619 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1620 				     journal_ioprio, is_remount) < 0)
1621 			return 0;
1622 	}
1623 #ifdef CONFIG_QUOTA
1624 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1625 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1626 			clear_opt(sb, USRQUOTA);
1627 
1628 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1629 			clear_opt(sb, GRPQUOTA);
1630 
1631 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1632 			ext4_msg(sb, KERN_ERR, "old and new quota "
1633 					"format mixing");
1634 			return 0;
1635 		}
1636 
1637 		if (!sbi->s_jquota_fmt) {
1638 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1639 					"not specified");
1640 			return 0;
1641 		}
1642 	} else {
1643 		if (sbi->s_jquota_fmt) {
1644 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1645 					"specified with no journaling "
1646 					"enabled");
1647 			return 0;
1648 		}
1649 	}
1650 #endif
1651 	return 1;
1652 }
1653 
1654 static inline void ext4_show_quota_options(struct seq_file *seq,
1655 					   struct super_block *sb)
1656 {
1657 #if defined(CONFIG_QUOTA)
1658 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1659 
1660 	if (sbi->s_jquota_fmt) {
1661 		char *fmtname = "";
1662 
1663 		switch (sbi->s_jquota_fmt) {
1664 		case QFMT_VFS_OLD:
1665 			fmtname = "vfsold";
1666 			break;
1667 		case QFMT_VFS_V0:
1668 			fmtname = "vfsv0";
1669 			break;
1670 		case QFMT_VFS_V1:
1671 			fmtname = "vfsv1";
1672 			break;
1673 		}
1674 		seq_printf(seq, ",jqfmt=%s", fmtname);
1675 	}
1676 
1677 	if (sbi->s_qf_names[USRQUOTA])
1678 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1679 
1680 	if (sbi->s_qf_names[GRPQUOTA])
1681 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1682 
1683 	if (test_opt(sb, USRQUOTA))
1684 		seq_puts(seq, ",usrquota");
1685 
1686 	if (test_opt(sb, GRPQUOTA))
1687 		seq_puts(seq, ",grpquota");
1688 #endif
1689 }
1690 
1691 static const char *token2str(int token)
1692 {
1693 	static const struct match_token *t;
1694 
1695 	for (t = tokens; t->token != Opt_err; t++)
1696 		if (t->token == token && !strchr(t->pattern, '='))
1697 			break;
1698 	return t->pattern;
1699 }
1700 
1701 /*
1702  * Show an option if
1703  *  - it's set to a non-default value OR
1704  *  - if the per-sb default is different from the global default
1705  */
1706 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1707 			      int nodefs)
1708 {
1709 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1710 	struct ext4_super_block *es = sbi->s_es;
1711 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1712 	const struct mount_opts *m;
1713 	char sep = nodefs ? '\n' : ',';
1714 
1715 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1716 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1717 
1718 	if (sbi->s_sb_block != 1)
1719 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1720 
1721 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1722 		int want_set = m->flags & MOPT_SET;
1723 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1724 		    (m->flags & MOPT_CLEAR_ERR))
1725 			continue;
1726 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1727 			continue; /* skip if same as the default */
1728 		if ((want_set &&
1729 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1730 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1731 			continue; /* select Opt_noFoo vs Opt_Foo */
1732 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1733 	}
1734 
1735 	if (nodefs || sbi->s_resuid != EXT4_DEF_RESUID ||
1736 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1737 		SEQ_OPTS_PRINT("resuid=%u", sbi->s_resuid);
1738 	if (nodefs || sbi->s_resgid != EXT4_DEF_RESGID ||
1739 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1740 		SEQ_OPTS_PRINT("resgid=%u", sbi->s_resgid);
1741 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1742 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1743 		SEQ_OPTS_PUTS("errors=remount-ro");
1744 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1745 		SEQ_OPTS_PUTS("errors=continue");
1746 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1747 		SEQ_OPTS_PUTS("errors=panic");
1748 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1749 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1750 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1751 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1752 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1753 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1754 	if (sb->s_flags & MS_I_VERSION)
1755 		SEQ_OPTS_PUTS("i_version");
1756 	if (nodefs || sbi->s_stripe)
1757 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1758 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1759 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1760 			SEQ_OPTS_PUTS("data=journal");
1761 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1762 			SEQ_OPTS_PUTS("data=ordered");
1763 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1764 			SEQ_OPTS_PUTS("data=writeback");
1765 	}
1766 	if (nodefs ||
1767 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1768 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1769 			       sbi->s_inode_readahead_blks);
1770 
1771 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1772 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1773 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1774 
1775 	ext4_show_quota_options(seq, sb);
1776 	return 0;
1777 }
1778 
1779 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1780 {
1781 	return _ext4_show_options(seq, root->d_sb, 0);
1782 }
1783 
1784 static int options_seq_show(struct seq_file *seq, void *offset)
1785 {
1786 	struct super_block *sb = seq->private;
1787 	int rc;
1788 
1789 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1790 	rc = _ext4_show_options(seq, sb, 1);
1791 	seq_puts(seq, "\n");
1792 	return rc;
1793 }
1794 
1795 static int options_open_fs(struct inode *inode, struct file *file)
1796 {
1797 	return single_open(file, options_seq_show, PDE(inode)->data);
1798 }
1799 
1800 static const struct file_operations ext4_seq_options_fops = {
1801 	.owner = THIS_MODULE,
1802 	.open = options_open_fs,
1803 	.read = seq_read,
1804 	.llseek = seq_lseek,
1805 	.release = single_release,
1806 };
1807 
1808 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1809 			    int read_only)
1810 {
1811 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1812 	int res = 0;
1813 
1814 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1815 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1816 			 "forcing read-only mode");
1817 		res = MS_RDONLY;
1818 	}
1819 	if (read_only)
1820 		goto done;
1821 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1822 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1823 			 "running e2fsck is recommended");
1824 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1825 		ext4_msg(sb, KERN_WARNING,
1826 			 "warning: mounting fs with errors, "
1827 			 "running e2fsck is recommended");
1828 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1829 		 le16_to_cpu(es->s_mnt_count) >=
1830 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1831 		ext4_msg(sb, KERN_WARNING,
1832 			 "warning: maximal mount count reached, "
1833 			 "running e2fsck is recommended");
1834 	else if (le32_to_cpu(es->s_checkinterval) &&
1835 		(le32_to_cpu(es->s_lastcheck) +
1836 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1837 		ext4_msg(sb, KERN_WARNING,
1838 			 "warning: checktime reached, "
1839 			 "running e2fsck is recommended");
1840 	if (!sbi->s_journal)
1841 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1842 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1843 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1844 	le16_add_cpu(&es->s_mnt_count, 1);
1845 	es->s_mtime = cpu_to_le32(get_seconds());
1846 	ext4_update_dynamic_rev(sb);
1847 	if (sbi->s_journal)
1848 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1849 
1850 	ext4_commit_super(sb, 1);
1851 done:
1852 	if (test_opt(sb, DEBUG))
1853 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1854 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1855 			sb->s_blocksize,
1856 			sbi->s_groups_count,
1857 			EXT4_BLOCKS_PER_GROUP(sb),
1858 			EXT4_INODES_PER_GROUP(sb),
1859 			sbi->s_mount_opt, sbi->s_mount_opt2);
1860 
1861 	cleancache_init_fs(sb);
1862 	return res;
1863 }
1864 
1865 static int ext4_fill_flex_info(struct super_block *sb)
1866 {
1867 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1868 	struct ext4_group_desc *gdp = NULL;
1869 	ext4_group_t flex_group_count;
1870 	ext4_group_t flex_group;
1871 	unsigned int groups_per_flex = 0;
1872 	size_t size;
1873 	int i;
1874 
1875 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1876 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1877 		sbi->s_log_groups_per_flex = 0;
1878 		return 1;
1879 	}
1880 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1881 
1882 	/* We allocate both existing and potentially added groups */
1883 	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1884 			((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1885 			      EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1886 	size = flex_group_count * sizeof(struct flex_groups);
1887 	sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
1888 	if (sbi->s_flex_groups == NULL) {
1889 		ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
1890 			 flex_group_count);
1891 		goto failed;
1892 	}
1893 
1894 	for (i = 0; i < sbi->s_groups_count; i++) {
1895 		gdp = ext4_get_group_desc(sb, i, NULL);
1896 
1897 		flex_group = ext4_flex_group(sbi, i);
1898 		atomic_add(ext4_free_inodes_count(sb, gdp),
1899 			   &sbi->s_flex_groups[flex_group].free_inodes);
1900 		atomic_add(ext4_free_group_clusters(sb, gdp),
1901 			   &sbi->s_flex_groups[flex_group].free_clusters);
1902 		atomic_add(ext4_used_dirs_count(sb, gdp),
1903 			   &sbi->s_flex_groups[flex_group].used_dirs);
1904 	}
1905 
1906 	return 1;
1907 failed:
1908 	return 0;
1909 }
1910 
1911 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1912 			    struct ext4_group_desc *gdp)
1913 {
1914 	__u16 crc = 0;
1915 
1916 	if (sbi->s_es->s_feature_ro_compat &
1917 	    cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1918 		int offset = offsetof(struct ext4_group_desc, bg_checksum);
1919 		__le32 le_group = cpu_to_le32(block_group);
1920 
1921 		crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1922 		crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1923 		crc = crc16(crc, (__u8 *)gdp, offset);
1924 		offset += sizeof(gdp->bg_checksum); /* skip checksum */
1925 		/* for checksum of struct ext4_group_desc do the rest...*/
1926 		if ((sbi->s_es->s_feature_incompat &
1927 		     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1928 		    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1929 			crc = crc16(crc, (__u8 *)gdp + offset,
1930 				    le16_to_cpu(sbi->s_es->s_desc_size) -
1931 					offset);
1932 	}
1933 
1934 	return cpu_to_le16(crc);
1935 }
1936 
1937 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1938 				struct ext4_group_desc *gdp)
1939 {
1940 	if ((sbi->s_es->s_feature_ro_compat &
1941 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1942 	    (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1943 		return 0;
1944 
1945 	return 1;
1946 }
1947 
1948 /* Called at mount-time, super-block is locked */
1949 static int ext4_check_descriptors(struct super_block *sb,
1950 				  ext4_group_t *first_not_zeroed)
1951 {
1952 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1953 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
1954 	ext4_fsblk_t last_block;
1955 	ext4_fsblk_t block_bitmap;
1956 	ext4_fsblk_t inode_bitmap;
1957 	ext4_fsblk_t inode_table;
1958 	int flexbg_flag = 0;
1959 	ext4_group_t i, grp = sbi->s_groups_count;
1960 
1961 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
1962 		flexbg_flag = 1;
1963 
1964 	ext4_debug("Checking group descriptors");
1965 
1966 	for (i = 0; i < sbi->s_groups_count; i++) {
1967 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
1968 
1969 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
1970 			last_block = ext4_blocks_count(sbi->s_es) - 1;
1971 		else
1972 			last_block = first_block +
1973 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
1974 
1975 		if ((grp == sbi->s_groups_count) &&
1976 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
1977 			grp = i;
1978 
1979 		block_bitmap = ext4_block_bitmap(sb, gdp);
1980 		if (block_bitmap < first_block || block_bitmap > last_block) {
1981 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1982 			       "Block bitmap for group %u not in group "
1983 			       "(block %llu)!", i, block_bitmap);
1984 			return 0;
1985 		}
1986 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
1987 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
1988 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1989 			       "Inode bitmap for group %u not in group "
1990 			       "(block %llu)!", i, inode_bitmap);
1991 			return 0;
1992 		}
1993 		inode_table = ext4_inode_table(sb, gdp);
1994 		if (inode_table < first_block ||
1995 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
1996 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
1997 			       "Inode table for group %u not in group "
1998 			       "(block %llu)!", i, inode_table);
1999 			return 0;
2000 		}
2001 		ext4_lock_group(sb, i);
2002 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2003 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2004 				 "Checksum for group %u failed (%u!=%u)",
2005 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2006 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2007 			if (!(sb->s_flags & MS_RDONLY)) {
2008 				ext4_unlock_group(sb, i);
2009 				return 0;
2010 			}
2011 		}
2012 		ext4_unlock_group(sb, i);
2013 		if (!flexbg_flag)
2014 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2015 	}
2016 	if (NULL != first_not_zeroed)
2017 		*first_not_zeroed = grp;
2018 
2019 	ext4_free_blocks_count_set(sbi->s_es,
2020 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2021 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2022 	return 1;
2023 }
2024 
2025 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2026  * the superblock) which were deleted from all directories, but held open by
2027  * a process at the time of a crash.  We walk the list and try to delete these
2028  * inodes at recovery time (only with a read-write filesystem).
2029  *
2030  * In order to keep the orphan inode chain consistent during traversal (in
2031  * case of crash during recovery), we link each inode into the superblock
2032  * orphan list_head and handle it the same way as an inode deletion during
2033  * normal operation (which journals the operations for us).
2034  *
2035  * We only do an iget() and an iput() on each inode, which is very safe if we
2036  * accidentally point at an in-use or already deleted inode.  The worst that
2037  * can happen in this case is that we get a "bit already cleared" message from
2038  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2039  * e2fsck was run on this filesystem, and it must have already done the orphan
2040  * inode cleanup for us, so we can safely abort without any further action.
2041  */
2042 static void ext4_orphan_cleanup(struct super_block *sb,
2043 				struct ext4_super_block *es)
2044 {
2045 	unsigned int s_flags = sb->s_flags;
2046 	int nr_orphans = 0, nr_truncates = 0;
2047 #ifdef CONFIG_QUOTA
2048 	int i;
2049 #endif
2050 	if (!es->s_last_orphan) {
2051 		jbd_debug(4, "no orphan inodes to clean up\n");
2052 		return;
2053 	}
2054 
2055 	if (bdev_read_only(sb->s_bdev)) {
2056 		ext4_msg(sb, KERN_ERR, "write access "
2057 			"unavailable, skipping orphan cleanup");
2058 		return;
2059 	}
2060 
2061 	/* Check if feature set would not allow a r/w mount */
2062 	if (!ext4_feature_set_ok(sb, 0)) {
2063 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2064 			 "unknown ROCOMPAT features");
2065 		return;
2066 	}
2067 
2068 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2069 		if (es->s_last_orphan)
2070 			jbd_debug(1, "Errors on filesystem, "
2071 				  "clearing orphan list.\n");
2072 		es->s_last_orphan = 0;
2073 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2074 		return;
2075 	}
2076 
2077 	if (s_flags & MS_RDONLY) {
2078 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2079 		sb->s_flags &= ~MS_RDONLY;
2080 	}
2081 #ifdef CONFIG_QUOTA
2082 	/* Needed for iput() to work correctly and not trash data */
2083 	sb->s_flags |= MS_ACTIVE;
2084 	/* Turn on quotas so that they are updated correctly */
2085 	for (i = 0; i < MAXQUOTAS; i++) {
2086 		if (EXT4_SB(sb)->s_qf_names[i]) {
2087 			int ret = ext4_quota_on_mount(sb, i);
2088 			if (ret < 0)
2089 				ext4_msg(sb, KERN_ERR,
2090 					"Cannot turn on journaled "
2091 					"quota: error %d", ret);
2092 		}
2093 	}
2094 #endif
2095 
2096 	while (es->s_last_orphan) {
2097 		struct inode *inode;
2098 
2099 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2100 		if (IS_ERR(inode)) {
2101 			es->s_last_orphan = 0;
2102 			break;
2103 		}
2104 
2105 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2106 		dquot_initialize(inode);
2107 		if (inode->i_nlink) {
2108 			ext4_msg(sb, KERN_DEBUG,
2109 				"%s: truncating inode %lu to %lld bytes",
2110 				__func__, inode->i_ino, inode->i_size);
2111 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2112 				  inode->i_ino, inode->i_size);
2113 			ext4_truncate(inode);
2114 			nr_truncates++;
2115 		} else {
2116 			ext4_msg(sb, KERN_DEBUG,
2117 				"%s: deleting unreferenced inode %lu",
2118 				__func__, inode->i_ino);
2119 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2120 				  inode->i_ino);
2121 			nr_orphans++;
2122 		}
2123 		iput(inode);  /* The delete magic happens here! */
2124 	}
2125 
2126 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2127 
2128 	if (nr_orphans)
2129 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2130 		       PLURAL(nr_orphans));
2131 	if (nr_truncates)
2132 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2133 		       PLURAL(nr_truncates));
2134 #ifdef CONFIG_QUOTA
2135 	/* Turn quotas off */
2136 	for (i = 0; i < MAXQUOTAS; i++) {
2137 		if (sb_dqopt(sb)->files[i])
2138 			dquot_quota_off(sb, i);
2139 	}
2140 #endif
2141 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2142 }
2143 
2144 /*
2145  * Maximal extent format file size.
2146  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2147  * extent format containers, within a sector_t, and within i_blocks
2148  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2149  * so that won't be a limiting factor.
2150  *
2151  * However there is other limiting factor. We do store extents in the form
2152  * of starting block and length, hence the resulting length of the extent
2153  * covering maximum file size must fit into on-disk format containers as
2154  * well. Given that length is always by 1 unit bigger than max unit (because
2155  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2156  *
2157  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2158  */
2159 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2160 {
2161 	loff_t res;
2162 	loff_t upper_limit = MAX_LFS_FILESIZE;
2163 
2164 	/* small i_blocks in vfs inode? */
2165 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2166 		/*
2167 		 * CONFIG_LBDAF is not enabled implies the inode
2168 		 * i_block represent total blocks in 512 bytes
2169 		 * 32 == size of vfs inode i_blocks * 8
2170 		 */
2171 		upper_limit = (1LL << 32) - 1;
2172 
2173 		/* total blocks in file system block size */
2174 		upper_limit >>= (blkbits - 9);
2175 		upper_limit <<= blkbits;
2176 	}
2177 
2178 	/*
2179 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2180 	 * by one fs block, so ee_len can cover the extent of maximum file
2181 	 * size
2182 	 */
2183 	res = (1LL << 32) - 1;
2184 	res <<= blkbits;
2185 
2186 	/* Sanity check against vm- & vfs- imposed limits */
2187 	if (res > upper_limit)
2188 		res = upper_limit;
2189 
2190 	return res;
2191 }
2192 
2193 /*
2194  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2195  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2196  * We need to be 1 filesystem block less than the 2^48 sector limit.
2197  */
2198 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2199 {
2200 	loff_t res = EXT4_NDIR_BLOCKS;
2201 	int meta_blocks;
2202 	loff_t upper_limit;
2203 	/* This is calculated to be the largest file size for a dense, block
2204 	 * mapped file such that the file's total number of 512-byte sectors,
2205 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2206 	 *
2207 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2208 	 * number of 512-byte sectors of the file.
2209 	 */
2210 
2211 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2212 		/*
2213 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2214 		 * the inode i_block field represents total file blocks in
2215 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2216 		 */
2217 		upper_limit = (1LL << 32) - 1;
2218 
2219 		/* total blocks in file system block size */
2220 		upper_limit >>= (bits - 9);
2221 
2222 	} else {
2223 		/*
2224 		 * We use 48 bit ext4_inode i_blocks
2225 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2226 		 * represent total number of blocks in
2227 		 * file system block size
2228 		 */
2229 		upper_limit = (1LL << 48) - 1;
2230 
2231 	}
2232 
2233 	/* indirect blocks */
2234 	meta_blocks = 1;
2235 	/* double indirect blocks */
2236 	meta_blocks += 1 + (1LL << (bits-2));
2237 	/* tripple indirect blocks */
2238 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2239 
2240 	upper_limit -= meta_blocks;
2241 	upper_limit <<= bits;
2242 
2243 	res += 1LL << (bits-2);
2244 	res += 1LL << (2*(bits-2));
2245 	res += 1LL << (3*(bits-2));
2246 	res <<= bits;
2247 	if (res > upper_limit)
2248 		res = upper_limit;
2249 
2250 	if (res > MAX_LFS_FILESIZE)
2251 		res = MAX_LFS_FILESIZE;
2252 
2253 	return res;
2254 }
2255 
2256 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2257 				   ext4_fsblk_t logical_sb_block, int nr)
2258 {
2259 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2260 	ext4_group_t bg, first_meta_bg;
2261 	int has_super = 0;
2262 
2263 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2264 
2265 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2266 	    nr < first_meta_bg)
2267 		return logical_sb_block + nr + 1;
2268 	bg = sbi->s_desc_per_block * nr;
2269 	if (ext4_bg_has_super(sb, bg))
2270 		has_super = 1;
2271 
2272 	return (has_super + ext4_group_first_block_no(sb, bg));
2273 }
2274 
2275 /**
2276  * ext4_get_stripe_size: Get the stripe size.
2277  * @sbi: In memory super block info
2278  *
2279  * If we have specified it via mount option, then
2280  * use the mount option value. If the value specified at mount time is
2281  * greater than the blocks per group use the super block value.
2282  * If the super block value is greater than blocks per group return 0.
2283  * Allocator needs it be less than blocks per group.
2284  *
2285  */
2286 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2287 {
2288 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2289 	unsigned long stripe_width =
2290 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2291 	int ret;
2292 
2293 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2294 		ret = sbi->s_stripe;
2295 	else if (stripe_width <= sbi->s_blocks_per_group)
2296 		ret = stripe_width;
2297 	else if (stride <= sbi->s_blocks_per_group)
2298 		ret = stride;
2299 	else
2300 		ret = 0;
2301 
2302 	/*
2303 	 * If the stripe width is 1, this makes no sense and
2304 	 * we set it to 0 to turn off stripe handling code.
2305 	 */
2306 	if (ret <= 1)
2307 		ret = 0;
2308 
2309 	return ret;
2310 }
2311 
2312 /* sysfs supprt */
2313 
2314 struct ext4_attr {
2315 	struct attribute attr;
2316 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2317 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2318 			 const char *, size_t);
2319 	int offset;
2320 };
2321 
2322 static int parse_strtoul(const char *buf,
2323 		unsigned long max, unsigned long *value)
2324 {
2325 	char *endp;
2326 
2327 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2328 	endp = skip_spaces(endp);
2329 	if (*endp || *value > max)
2330 		return -EINVAL;
2331 
2332 	return 0;
2333 }
2334 
2335 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2336 					      struct ext4_sb_info *sbi,
2337 					      char *buf)
2338 {
2339 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2340 		(s64) EXT4_C2B(sbi,
2341 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2342 }
2343 
2344 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2345 					 struct ext4_sb_info *sbi, char *buf)
2346 {
2347 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2348 
2349 	if (!sb->s_bdev->bd_part)
2350 		return snprintf(buf, PAGE_SIZE, "0\n");
2351 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2352 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2353 			 sbi->s_sectors_written_start) >> 1);
2354 }
2355 
2356 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2357 					  struct ext4_sb_info *sbi, char *buf)
2358 {
2359 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2360 
2361 	if (!sb->s_bdev->bd_part)
2362 		return snprintf(buf, PAGE_SIZE, "0\n");
2363 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2364 			(unsigned long long)(sbi->s_kbytes_written +
2365 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2366 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2367 }
2368 
2369 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2370 					  struct ext4_sb_info *sbi,
2371 					  const char *buf, size_t count)
2372 {
2373 	unsigned long t;
2374 
2375 	if (parse_strtoul(buf, 0x40000000, &t))
2376 		return -EINVAL;
2377 
2378 	if (t && !is_power_of_2(t))
2379 		return -EINVAL;
2380 
2381 	sbi->s_inode_readahead_blks = t;
2382 	return count;
2383 }
2384 
2385 static ssize_t sbi_ui_show(struct ext4_attr *a,
2386 			   struct ext4_sb_info *sbi, char *buf)
2387 {
2388 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2389 
2390 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2391 }
2392 
2393 static ssize_t sbi_ui_store(struct ext4_attr *a,
2394 			    struct ext4_sb_info *sbi,
2395 			    const char *buf, size_t count)
2396 {
2397 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2398 	unsigned long t;
2399 
2400 	if (parse_strtoul(buf, 0xffffffff, &t))
2401 		return -EINVAL;
2402 	*ui = t;
2403 	return count;
2404 }
2405 
2406 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2407 static struct ext4_attr ext4_attr_##_name = {			\
2408 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2409 	.show	= _show,					\
2410 	.store	= _store,					\
2411 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2412 }
2413 #define EXT4_ATTR(name, mode, show, store) \
2414 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2415 
2416 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2417 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2418 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2419 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2420 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2421 #define ATTR_LIST(name) &ext4_attr_##name.attr
2422 
2423 EXT4_RO_ATTR(delayed_allocation_blocks);
2424 EXT4_RO_ATTR(session_write_kbytes);
2425 EXT4_RO_ATTR(lifetime_write_kbytes);
2426 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2427 		 inode_readahead_blks_store, s_inode_readahead_blks);
2428 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2429 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2430 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2431 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2432 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2433 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2434 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2435 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2436 
2437 static struct attribute *ext4_attrs[] = {
2438 	ATTR_LIST(delayed_allocation_blocks),
2439 	ATTR_LIST(session_write_kbytes),
2440 	ATTR_LIST(lifetime_write_kbytes),
2441 	ATTR_LIST(inode_readahead_blks),
2442 	ATTR_LIST(inode_goal),
2443 	ATTR_LIST(mb_stats),
2444 	ATTR_LIST(mb_max_to_scan),
2445 	ATTR_LIST(mb_min_to_scan),
2446 	ATTR_LIST(mb_order2_req),
2447 	ATTR_LIST(mb_stream_req),
2448 	ATTR_LIST(mb_group_prealloc),
2449 	ATTR_LIST(max_writeback_mb_bump),
2450 	NULL,
2451 };
2452 
2453 /* Features this copy of ext4 supports */
2454 EXT4_INFO_ATTR(lazy_itable_init);
2455 EXT4_INFO_ATTR(batched_discard);
2456 
2457 static struct attribute *ext4_feat_attrs[] = {
2458 	ATTR_LIST(lazy_itable_init),
2459 	ATTR_LIST(batched_discard),
2460 	NULL,
2461 };
2462 
2463 static ssize_t ext4_attr_show(struct kobject *kobj,
2464 			      struct attribute *attr, char *buf)
2465 {
2466 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2467 						s_kobj);
2468 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2469 
2470 	return a->show ? a->show(a, sbi, buf) : 0;
2471 }
2472 
2473 static ssize_t ext4_attr_store(struct kobject *kobj,
2474 			       struct attribute *attr,
2475 			       const char *buf, size_t len)
2476 {
2477 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2478 						s_kobj);
2479 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2480 
2481 	return a->store ? a->store(a, sbi, buf, len) : 0;
2482 }
2483 
2484 static void ext4_sb_release(struct kobject *kobj)
2485 {
2486 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2487 						s_kobj);
2488 	complete(&sbi->s_kobj_unregister);
2489 }
2490 
2491 static const struct sysfs_ops ext4_attr_ops = {
2492 	.show	= ext4_attr_show,
2493 	.store	= ext4_attr_store,
2494 };
2495 
2496 static struct kobj_type ext4_ktype = {
2497 	.default_attrs	= ext4_attrs,
2498 	.sysfs_ops	= &ext4_attr_ops,
2499 	.release	= ext4_sb_release,
2500 };
2501 
2502 static void ext4_feat_release(struct kobject *kobj)
2503 {
2504 	complete(&ext4_feat->f_kobj_unregister);
2505 }
2506 
2507 static struct kobj_type ext4_feat_ktype = {
2508 	.default_attrs	= ext4_feat_attrs,
2509 	.sysfs_ops	= &ext4_attr_ops,
2510 	.release	= ext4_feat_release,
2511 };
2512 
2513 /*
2514  * Check whether this filesystem can be mounted based on
2515  * the features present and the RDONLY/RDWR mount requested.
2516  * Returns 1 if this filesystem can be mounted as requested,
2517  * 0 if it cannot be.
2518  */
2519 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2520 {
2521 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2522 		ext4_msg(sb, KERN_ERR,
2523 			"Couldn't mount because of "
2524 			"unsupported optional features (%x)",
2525 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2526 			~EXT4_FEATURE_INCOMPAT_SUPP));
2527 		return 0;
2528 	}
2529 
2530 	if (readonly)
2531 		return 1;
2532 
2533 	/* Check that feature set is OK for a read-write mount */
2534 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2535 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2536 			 "unsupported optional features (%x)",
2537 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2538 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2539 		return 0;
2540 	}
2541 	/*
2542 	 * Large file size enabled file system can only be mounted
2543 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2544 	 */
2545 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2546 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2547 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2548 				 "cannot be mounted RDWR without "
2549 				 "CONFIG_LBDAF");
2550 			return 0;
2551 		}
2552 	}
2553 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2554 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2555 		ext4_msg(sb, KERN_ERR,
2556 			 "Can't support bigalloc feature without "
2557 			 "extents feature\n");
2558 		return 0;
2559 	}
2560 	return 1;
2561 }
2562 
2563 /*
2564  * This function is called once a day if we have errors logged
2565  * on the file system
2566  */
2567 static void print_daily_error_info(unsigned long arg)
2568 {
2569 	struct super_block *sb = (struct super_block *) arg;
2570 	struct ext4_sb_info *sbi;
2571 	struct ext4_super_block *es;
2572 
2573 	sbi = EXT4_SB(sb);
2574 	es = sbi->s_es;
2575 
2576 	if (es->s_error_count)
2577 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2578 			 le32_to_cpu(es->s_error_count));
2579 	if (es->s_first_error_time) {
2580 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2581 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2582 		       (int) sizeof(es->s_first_error_func),
2583 		       es->s_first_error_func,
2584 		       le32_to_cpu(es->s_first_error_line));
2585 		if (es->s_first_error_ino)
2586 			printk(": inode %u",
2587 			       le32_to_cpu(es->s_first_error_ino));
2588 		if (es->s_first_error_block)
2589 			printk(": block %llu", (unsigned long long)
2590 			       le64_to_cpu(es->s_first_error_block));
2591 		printk("\n");
2592 	}
2593 	if (es->s_last_error_time) {
2594 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2595 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2596 		       (int) sizeof(es->s_last_error_func),
2597 		       es->s_last_error_func,
2598 		       le32_to_cpu(es->s_last_error_line));
2599 		if (es->s_last_error_ino)
2600 			printk(": inode %u",
2601 			       le32_to_cpu(es->s_last_error_ino));
2602 		if (es->s_last_error_block)
2603 			printk(": block %llu", (unsigned long long)
2604 			       le64_to_cpu(es->s_last_error_block));
2605 		printk("\n");
2606 	}
2607 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2608 }
2609 
2610 /* Find next suitable group and run ext4_init_inode_table */
2611 static int ext4_run_li_request(struct ext4_li_request *elr)
2612 {
2613 	struct ext4_group_desc *gdp = NULL;
2614 	ext4_group_t group, ngroups;
2615 	struct super_block *sb;
2616 	unsigned long timeout = 0;
2617 	int ret = 0;
2618 
2619 	sb = elr->lr_super;
2620 	ngroups = EXT4_SB(sb)->s_groups_count;
2621 
2622 	for (group = elr->lr_next_group; group < ngroups; group++) {
2623 		gdp = ext4_get_group_desc(sb, group, NULL);
2624 		if (!gdp) {
2625 			ret = 1;
2626 			break;
2627 		}
2628 
2629 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2630 			break;
2631 	}
2632 
2633 	if (group == ngroups)
2634 		ret = 1;
2635 
2636 	if (!ret) {
2637 		timeout = jiffies;
2638 		ret = ext4_init_inode_table(sb, group,
2639 					    elr->lr_timeout ? 0 : 1);
2640 		if (elr->lr_timeout == 0) {
2641 			timeout = (jiffies - timeout) *
2642 				  elr->lr_sbi->s_li_wait_mult;
2643 			elr->lr_timeout = timeout;
2644 		}
2645 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2646 		elr->lr_next_group = group + 1;
2647 	}
2648 
2649 	return ret;
2650 }
2651 
2652 /*
2653  * Remove lr_request from the list_request and free the
2654  * request structure. Should be called with li_list_mtx held
2655  */
2656 static void ext4_remove_li_request(struct ext4_li_request *elr)
2657 {
2658 	struct ext4_sb_info *sbi;
2659 
2660 	if (!elr)
2661 		return;
2662 
2663 	sbi = elr->lr_sbi;
2664 
2665 	list_del(&elr->lr_request);
2666 	sbi->s_li_request = NULL;
2667 	kfree(elr);
2668 }
2669 
2670 static void ext4_unregister_li_request(struct super_block *sb)
2671 {
2672 	mutex_lock(&ext4_li_mtx);
2673 	if (!ext4_li_info) {
2674 		mutex_unlock(&ext4_li_mtx);
2675 		return;
2676 	}
2677 
2678 	mutex_lock(&ext4_li_info->li_list_mtx);
2679 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2680 	mutex_unlock(&ext4_li_info->li_list_mtx);
2681 	mutex_unlock(&ext4_li_mtx);
2682 }
2683 
2684 static struct task_struct *ext4_lazyinit_task;
2685 
2686 /*
2687  * This is the function where ext4lazyinit thread lives. It walks
2688  * through the request list searching for next scheduled filesystem.
2689  * When such a fs is found, run the lazy initialization request
2690  * (ext4_rn_li_request) and keep track of the time spend in this
2691  * function. Based on that time we compute next schedule time of
2692  * the request. When walking through the list is complete, compute
2693  * next waking time and put itself into sleep.
2694  */
2695 static int ext4_lazyinit_thread(void *arg)
2696 {
2697 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2698 	struct list_head *pos, *n;
2699 	struct ext4_li_request *elr;
2700 	unsigned long next_wakeup, cur;
2701 
2702 	BUG_ON(NULL == eli);
2703 
2704 cont_thread:
2705 	while (true) {
2706 		next_wakeup = MAX_JIFFY_OFFSET;
2707 
2708 		mutex_lock(&eli->li_list_mtx);
2709 		if (list_empty(&eli->li_request_list)) {
2710 			mutex_unlock(&eli->li_list_mtx);
2711 			goto exit_thread;
2712 		}
2713 
2714 		list_for_each_safe(pos, n, &eli->li_request_list) {
2715 			elr = list_entry(pos, struct ext4_li_request,
2716 					 lr_request);
2717 
2718 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2719 				if (ext4_run_li_request(elr) != 0) {
2720 					/* error, remove the lazy_init job */
2721 					ext4_remove_li_request(elr);
2722 					continue;
2723 				}
2724 			}
2725 
2726 			if (time_before(elr->lr_next_sched, next_wakeup))
2727 				next_wakeup = elr->lr_next_sched;
2728 		}
2729 		mutex_unlock(&eli->li_list_mtx);
2730 
2731 		try_to_freeze();
2732 
2733 		cur = jiffies;
2734 		if ((time_after_eq(cur, next_wakeup)) ||
2735 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2736 			cond_resched();
2737 			continue;
2738 		}
2739 
2740 		schedule_timeout_interruptible(next_wakeup - cur);
2741 
2742 		if (kthread_should_stop()) {
2743 			ext4_clear_request_list();
2744 			goto exit_thread;
2745 		}
2746 	}
2747 
2748 exit_thread:
2749 	/*
2750 	 * It looks like the request list is empty, but we need
2751 	 * to check it under the li_list_mtx lock, to prevent any
2752 	 * additions into it, and of course we should lock ext4_li_mtx
2753 	 * to atomically free the list and ext4_li_info, because at
2754 	 * this point another ext4 filesystem could be registering
2755 	 * new one.
2756 	 */
2757 	mutex_lock(&ext4_li_mtx);
2758 	mutex_lock(&eli->li_list_mtx);
2759 	if (!list_empty(&eli->li_request_list)) {
2760 		mutex_unlock(&eli->li_list_mtx);
2761 		mutex_unlock(&ext4_li_mtx);
2762 		goto cont_thread;
2763 	}
2764 	mutex_unlock(&eli->li_list_mtx);
2765 	kfree(ext4_li_info);
2766 	ext4_li_info = NULL;
2767 	mutex_unlock(&ext4_li_mtx);
2768 
2769 	return 0;
2770 }
2771 
2772 static void ext4_clear_request_list(void)
2773 {
2774 	struct list_head *pos, *n;
2775 	struct ext4_li_request *elr;
2776 
2777 	mutex_lock(&ext4_li_info->li_list_mtx);
2778 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2779 		elr = list_entry(pos, struct ext4_li_request,
2780 				 lr_request);
2781 		ext4_remove_li_request(elr);
2782 	}
2783 	mutex_unlock(&ext4_li_info->li_list_mtx);
2784 }
2785 
2786 static int ext4_run_lazyinit_thread(void)
2787 {
2788 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2789 					 ext4_li_info, "ext4lazyinit");
2790 	if (IS_ERR(ext4_lazyinit_task)) {
2791 		int err = PTR_ERR(ext4_lazyinit_task);
2792 		ext4_clear_request_list();
2793 		kfree(ext4_li_info);
2794 		ext4_li_info = NULL;
2795 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2796 				 "initialization thread\n",
2797 				 err);
2798 		return err;
2799 	}
2800 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2801 	return 0;
2802 }
2803 
2804 /*
2805  * Check whether it make sense to run itable init. thread or not.
2806  * If there is at least one uninitialized inode table, return
2807  * corresponding group number, else the loop goes through all
2808  * groups and return total number of groups.
2809  */
2810 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2811 {
2812 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2813 	struct ext4_group_desc *gdp = NULL;
2814 
2815 	for (group = 0; group < ngroups; group++) {
2816 		gdp = ext4_get_group_desc(sb, group, NULL);
2817 		if (!gdp)
2818 			continue;
2819 
2820 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2821 			break;
2822 	}
2823 
2824 	return group;
2825 }
2826 
2827 static int ext4_li_info_new(void)
2828 {
2829 	struct ext4_lazy_init *eli = NULL;
2830 
2831 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2832 	if (!eli)
2833 		return -ENOMEM;
2834 
2835 	INIT_LIST_HEAD(&eli->li_request_list);
2836 	mutex_init(&eli->li_list_mtx);
2837 
2838 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2839 
2840 	ext4_li_info = eli;
2841 
2842 	return 0;
2843 }
2844 
2845 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2846 					    ext4_group_t start)
2847 {
2848 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2849 	struct ext4_li_request *elr;
2850 	unsigned long rnd;
2851 
2852 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2853 	if (!elr)
2854 		return NULL;
2855 
2856 	elr->lr_super = sb;
2857 	elr->lr_sbi = sbi;
2858 	elr->lr_next_group = start;
2859 
2860 	/*
2861 	 * Randomize first schedule time of the request to
2862 	 * spread the inode table initialization requests
2863 	 * better.
2864 	 */
2865 	get_random_bytes(&rnd, sizeof(rnd));
2866 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
2867 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2868 
2869 	return elr;
2870 }
2871 
2872 static int ext4_register_li_request(struct super_block *sb,
2873 				    ext4_group_t first_not_zeroed)
2874 {
2875 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2876 	struct ext4_li_request *elr;
2877 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2878 	int ret = 0;
2879 
2880 	if (sbi->s_li_request != NULL) {
2881 		/*
2882 		 * Reset timeout so it can be computed again, because
2883 		 * s_li_wait_mult might have changed.
2884 		 */
2885 		sbi->s_li_request->lr_timeout = 0;
2886 		return 0;
2887 	}
2888 
2889 	if (first_not_zeroed == ngroups ||
2890 	    (sb->s_flags & MS_RDONLY) ||
2891 	    !test_opt(sb, INIT_INODE_TABLE))
2892 		return 0;
2893 
2894 	elr = ext4_li_request_new(sb, first_not_zeroed);
2895 	if (!elr)
2896 		return -ENOMEM;
2897 
2898 	mutex_lock(&ext4_li_mtx);
2899 
2900 	if (NULL == ext4_li_info) {
2901 		ret = ext4_li_info_new();
2902 		if (ret)
2903 			goto out;
2904 	}
2905 
2906 	mutex_lock(&ext4_li_info->li_list_mtx);
2907 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2908 	mutex_unlock(&ext4_li_info->li_list_mtx);
2909 
2910 	sbi->s_li_request = elr;
2911 	/*
2912 	 * set elr to NULL here since it has been inserted to
2913 	 * the request_list and the removal and free of it is
2914 	 * handled by ext4_clear_request_list from now on.
2915 	 */
2916 	elr = NULL;
2917 
2918 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2919 		ret = ext4_run_lazyinit_thread();
2920 		if (ret)
2921 			goto out;
2922 	}
2923 out:
2924 	mutex_unlock(&ext4_li_mtx);
2925 	if (ret)
2926 		kfree(elr);
2927 	return ret;
2928 }
2929 
2930 /*
2931  * We do not need to lock anything since this is called on
2932  * module unload.
2933  */
2934 static void ext4_destroy_lazyinit_thread(void)
2935 {
2936 	/*
2937 	 * If thread exited earlier
2938 	 * there's nothing to be done.
2939 	 */
2940 	if (!ext4_li_info || !ext4_lazyinit_task)
2941 		return;
2942 
2943 	kthread_stop(ext4_lazyinit_task);
2944 }
2945 
2946 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2947 {
2948 	char *orig_data = kstrdup(data, GFP_KERNEL);
2949 	struct buffer_head *bh;
2950 	struct ext4_super_block *es = NULL;
2951 	struct ext4_sb_info *sbi;
2952 	ext4_fsblk_t block;
2953 	ext4_fsblk_t sb_block = get_sb_block(&data);
2954 	ext4_fsblk_t logical_sb_block;
2955 	unsigned long offset = 0;
2956 	unsigned long journal_devnum = 0;
2957 	unsigned long def_mount_opts;
2958 	struct inode *root;
2959 	char *cp;
2960 	const char *descr;
2961 	int ret = -ENOMEM;
2962 	int blocksize, clustersize;
2963 	unsigned int db_count;
2964 	unsigned int i;
2965 	int needs_recovery, has_huge_files, has_bigalloc;
2966 	__u64 blocks_count;
2967 	int err;
2968 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
2969 	ext4_group_t first_not_zeroed;
2970 
2971 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
2972 	if (!sbi)
2973 		goto out_free_orig;
2974 
2975 	sbi->s_blockgroup_lock =
2976 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
2977 	if (!sbi->s_blockgroup_lock) {
2978 		kfree(sbi);
2979 		goto out_free_orig;
2980 	}
2981 	sb->s_fs_info = sbi;
2982 	sbi->s_mount_opt = 0;
2983 	sbi->s_resuid = EXT4_DEF_RESUID;
2984 	sbi->s_resgid = EXT4_DEF_RESGID;
2985 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
2986 	sbi->s_sb_block = sb_block;
2987 	if (sb->s_bdev->bd_part)
2988 		sbi->s_sectors_written_start =
2989 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
2990 
2991 	/* Cleanup superblock name */
2992 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
2993 		*cp = '!';
2994 
2995 	ret = -EINVAL;
2996 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
2997 	if (!blocksize) {
2998 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
2999 		goto out_fail;
3000 	}
3001 
3002 	/*
3003 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3004 	 * block sizes.  We need to calculate the offset from buffer start.
3005 	 */
3006 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3007 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3008 		offset = do_div(logical_sb_block, blocksize);
3009 	} else {
3010 		logical_sb_block = sb_block;
3011 	}
3012 
3013 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3014 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3015 		goto out_fail;
3016 	}
3017 	/*
3018 	 * Note: s_es must be initialized as soon as possible because
3019 	 *       some ext4 macro-instructions depend on its value
3020 	 */
3021 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3022 	sbi->s_es = es;
3023 	sb->s_magic = le16_to_cpu(es->s_magic);
3024 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3025 		goto cantfind_ext4;
3026 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3027 
3028 	/* Set defaults before we parse the mount options */
3029 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3030 	set_opt(sb, INIT_INODE_TABLE);
3031 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3032 		set_opt(sb, DEBUG);
3033 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3034 		set_opt(sb, GRPID);
3035 	if (def_mount_opts & EXT4_DEFM_UID16)
3036 		set_opt(sb, NO_UID32);
3037 	/* xattr user namespace & acls are now defaulted on */
3038 #ifdef CONFIG_EXT4_FS_XATTR
3039 	set_opt(sb, XATTR_USER);
3040 #endif
3041 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3042 	set_opt(sb, POSIX_ACL);
3043 #endif
3044 	set_opt(sb, MBLK_IO_SUBMIT);
3045 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3046 		set_opt(sb, JOURNAL_DATA);
3047 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3048 		set_opt(sb, ORDERED_DATA);
3049 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3050 		set_opt(sb, WRITEBACK_DATA);
3051 
3052 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3053 		set_opt(sb, ERRORS_PANIC);
3054 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3055 		set_opt(sb, ERRORS_CONT);
3056 	else
3057 		set_opt(sb, ERRORS_RO);
3058 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3059 		set_opt(sb, BLOCK_VALIDITY);
3060 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3061 		set_opt(sb, DISCARD);
3062 
3063 	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
3064 	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
3065 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3066 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3067 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3068 
3069 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3070 		set_opt(sb, BARRIER);
3071 
3072 	/*
3073 	 * enable delayed allocation by default
3074 	 * Use -o nodelalloc to turn it off
3075 	 */
3076 	if (!IS_EXT3_SB(sb) &&
3077 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3078 		set_opt(sb, DELALLOC);
3079 
3080 	/*
3081 	 * set default s_li_wait_mult for lazyinit, for the case there is
3082 	 * no mount option specified.
3083 	 */
3084 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3085 
3086 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3087 			   &journal_devnum, &journal_ioprio, 0)) {
3088 		ext4_msg(sb, KERN_WARNING,
3089 			 "failed to parse options in superblock: %s",
3090 			 sbi->s_es->s_mount_opts);
3091 	}
3092 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3093 	if (!parse_options((char *) data, sb, &journal_devnum,
3094 			   &journal_ioprio, 0))
3095 		goto failed_mount;
3096 
3097 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3098 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3099 			    "with data=journal disables delayed "
3100 			    "allocation and O_DIRECT support!\n");
3101 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3102 			ext4_msg(sb, KERN_ERR, "can't mount with "
3103 				 "both data=journal and delalloc");
3104 			goto failed_mount;
3105 		}
3106 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3107 			ext4_msg(sb, KERN_ERR, "can't mount with "
3108 				 "both data=journal and delalloc");
3109 			goto failed_mount;
3110 		}
3111 		if (test_opt(sb, DELALLOC))
3112 			clear_opt(sb, DELALLOC);
3113 	}
3114 
3115 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3116 	if (test_opt(sb, DIOREAD_NOLOCK)) {
3117 		if (blocksize < PAGE_SIZE) {
3118 			ext4_msg(sb, KERN_ERR, "can't mount with "
3119 				 "dioread_nolock if block size != PAGE_SIZE");
3120 			goto failed_mount;
3121 		}
3122 	}
3123 
3124 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3125 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3126 
3127 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3128 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3129 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3130 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3131 		ext4_msg(sb, KERN_WARNING,
3132 		       "feature flags set on rev 0 fs, "
3133 		       "running e2fsck is recommended");
3134 
3135 	if (IS_EXT2_SB(sb)) {
3136 		if (ext2_feature_set_ok(sb))
3137 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3138 				 "using the ext4 subsystem");
3139 		else {
3140 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3141 				 "to feature incompatibilities");
3142 			goto failed_mount;
3143 		}
3144 	}
3145 
3146 	if (IS_EXT3_SB(sb)) {
3147 		if (ext3_feature_set_ok(sb))
3148 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3149 				 "using the ext4 subsystem");
3150 		else {
3151 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3152 				 "to feature incompatibilities");
3153 			goto failed_mount;
3154 		}
3155 	}
3156 
3157 	/*
3158 	 * Check feature flags regardless of the revision level, since we
3159 	 * previously didn't change the revision level when setting the flags,
3160 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3161 	 */
3162 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3163 		goto failed_mount;
3164 
3165 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3166 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3167 		ext4_msg(sb, KERN_ERR,
3168 		       "Unsupported filesystem blocksize %d", blocksize);
3169 		goto failed_mount;
3170 	}
3171 
3172 	if (sb->s_blocksize != blocksize) {
3173 		/* Validate the filesystem blocksize */
3174 		if (!sb_set_blocksize(sb, blocksize)) {
3175 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3176 					blocksize);
3177 			goto failed_mount;
3178 		}
3179 
3180 		brelse(bh);
3181 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3182 		offset = do_div(logical_sb_block, blocksize);
3183 		bh = sb_bread(sb, logical_sb_block);
3184 		if (!bh) {
3185 			ext4_msg(sb, KERN_ERR,
3186 			       "Can't read superblock on 2nd try");
3187 			goto failed_mount;
3188 		}
3189 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
3190 		sbi->s_es = es;
3191 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3192 			ext4_msg(sb, KERN_ERR,
3193 			       "Magic mismatch, very weird!");
3194 			goto failed_mount;
3195 		}
3196 	}
3197 
3198 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3199 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3200 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3201 						      has_huge_files);
3202 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3203 
3204 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3205 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3206 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3207 	} else {
3208 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3209 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3210 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3211 		    (!is_power_of_2(sbi->s_inode_size)) ||
3212 		    (sbi->s_inode_size > blocksize)) {
3213 			ext4_msg(sb, KERN_ERR,
3214 			       "unsupported inode size: %d",
3215 			       sbi->s_inode_size);
3216 			goto failed_mount;
3217 		}
3218 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3219 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3220 	}
3221 
3222 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3223 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3224 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3225 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3226 		    !is_power_of_2(sbi->s_desc_size)) {
3227 			ext4_msg(sb, KERN_ERR,
3228 			       "unsupported descriptor size %lu",
3229 			       sbi->s_desc_size);
3230 			goto failed_mount;
3231 		}
3232 	} else
3233 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3234 
3235 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3236 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3237 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3238 		goto cantfind_ext4;
3239 
3240 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3241 	if (sbi->s_inodes_per_block == 0)
3242 		goto cantfind_ext4;
3243 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3244 					sbi->s_inodes_per_block;
3245 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3246 	sbi->s_sbh = bh;
3247 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3248 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3249 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3250 
3251 	for (i = 0; i < 4; i++)
3252 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3253 	sbi->s_def_hash_version = es->s_def_hash_version;
3254 	i = le32_to_cpu(es->s_flags);
3255 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3256 		sbi->s_hash_unsigned = 3;
3257 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3258 #ifdef __CHAR_UNSIGNED__
3259 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3260 		sbi->s_hash_unsigned = 3;
3261 #else
3262 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3263 #endif
3264 	}
3265 
3266 	/* Handle clustersize */
3267 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3268 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3269 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3270 	if (has_bigalloc) {
3271 		if (clustersize < blocksize) {
3272 			ext4_msg(sb, KERN_ERR,
3273 				 "cluster size (%d) smaller than "
3274 				 "block size (%d)", clustersize, blocksize);
3275 			goto failed_mount;
3276 		}
3277 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3278 			le32_to_cpu(es->s_log_block_size);
3279 		sbi->s_clusters_per_group =
3280 			le32_to_cpu(es->s_clusters_per_group);
3281 		if (sbi->s_clusters_per_group > blocksize * 8) {
3282 			ext4_msg(sb, KERN_ERR,
3283 				 "#clusters per group too big: %lu",
3284 				 sbi->s_clusters_per_group);
3285 			goto failed_mount;
3286 		}
3287 		if (sbi->s_blocks_per_group !=
3288 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3289 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3290 				 "clusters per group (%lu) inconsistent",
3291 				 sbi->s_blocks_per_group,
3292 				 sbi->s_clusters_per_group);
3293 			goto failed_mount;
3294 		}
3295 	} else {
3296 		if (clustersize != blocksize) {
3297 			ext4_warning(sb, "fragment/cluster size (%d) != "
3298 				     "block size (%d)", clustersize,
3299 				     blocksize);
3300 			clustersize = blocksize;
3301 		}
3302 		if (sbi->s_blocks_per_group > blocksize * 8) {
3303 			ext4_msg(sb, KERN_ERR,
3304 				 "#blocks per group too big: %lu",
3305 				 sbi->s_blocks_per_group);
3306 			goto failed_mount;
3307 		}
3308 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3309 		sbi->s_cluster_bits = 0;
3310 	}
3311 	sbi->s_cluster_ratio = clustersize / blocksize;
3312 
3313 	if (sbi->s_inodes_per_group > blocksize * 8) {
3314 		ext4_msg(sb, KERN_ERR,
3315 		       "#inodes per group too big: %lu",
3316 		       sbi->s_inodes_per_group);
3317 		goto failed_mount;
3318 	}
3319 
3320 	/*
3321 	 * Test whether we have more sectors than will fit in sector_t,
3322 	 * and whether the max offset is addressable by the page cache.
3323 	 */
3324 	err = generic_check_addressable(sb->s_blocksize_bits,
3325 					ext4_blocks_count(es));
3326 	if (err) {
3327 		ext4_msg(sb, KERN_ERR, "filesystem"
3328 			 " too large to mount safely on this system");
3329 		if (sizeof(sector_t) < 8)
3330 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3331 		ret = err;
3332 		goto failed_mount;
3333 	}
3334 
3335 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3336 		goto cantfind_ext4;
3337 
3338 	/* check blocks count against device size */
3339 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3340 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3341 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3342 		       "exceeds size of device (%llu blocks)",
3343 		       ext4_blocks_count(es), blocks_count);
3344 		goto failed_mount;
3345 	}
3346 
3347 	/*
3348 	 * It makes no sense for the first data block to be beyond the end
3349 	 * of the filesystem.
3350 	 */
3351 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3352 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3353 			 "block %u is beyond end of filesystem (%llu)",
3354 			 le32_to_cpu(es->s_first_data_block),
3355 			 ext4_blocks_count(es));
3356 		goto failed_mount;
3357 	}
3358 	blocks_count = (ext4_blocks_count(es) -
3359 			le32_to_cpu(es->s_first_data_block) +
3360 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3361 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3362 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3363 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3364 		       "(block count %llu, first data block %u, "
3365 		       "blocks per group %lu)", sbi->s_groups_count,
3366 		       ext4_blocks_count(es),
3367 		       le32_to_cpu(es->s_first_data_block),
3368 		       EXT4_BLOCKS_PER_GROUP(sb));
3369 		goto failed_mount;
3370 	}
3371 	sbi->s_groups_count = blocks_count;
3372 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3373 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3374 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3375 		   EXT4_DESC_PER_BLOCK(sb);
3376 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3377 					  sizeof(struct buffer_head *),
3378 					  GFP_KERNEL);
3379 	if (sbi->s_group_desc == NULL) {
3380 		ext4_msg(sb, KERN_ERR, "not enough memory");
3381 		goto failed_mount;
3382 	}
3383 
3384 	if (ext4_proc_root)
3385 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3386 
3387 	if (sbi->s_proc)
3388 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3389 				 &ext4_seq_options_fops, sb);
3390 
3391 	bgl_lock_init(sbi->s_blockgroup_lock);
3392 
3393 	for (i = 0; i < db_count; i++) {
3394 		block = descriptor_loc(sb, logical_sb_block, i);
3395 		sbi->s_group_desc[i] = sb_bread(sb, block);
3396 		if (!sbi->s_group_desc[i]) {
3397 			ext4_msg(sb, KERN_ERR,
3398 			       "can't read group descriptor %d", i);
3399 			db_count = i;
3400 			goto failed_mount2;
3401 		}
3402 	}
3403 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3404 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3405 		goto failed_mount2;
3406 	}
3407 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3408 		if (!ext4_fill_flex_info(sb)) {
3409 			ext4_msg(sb, KERN_ERR,
3410 			       "unable to initialize "
3411 			       "flex_bg meta info!");
3412 			goto failed_mount2;
3413 		}
3414 
3415 	sbi->s_gdb_count = db_count;
3416 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3417 	spin_lock_init(&sbi->s_next_gen_lock);
3418 
3419 	init_timer(&sbi->s_err_report);
3420 	sbi->s_err_report.function = print_daily_error_info;
3421 	sbi->s_err_report.data = (unsigned long) sb;
3422 
3423 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3424 			ext4_count_free_clusters(sb));
3425 	if (!err) {
3426 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3427 				ext4_count_free_inodes(sb));
3428 	}
3429 	if (!err) {
3430 		err = percpu_counter_init(&sbi->s_dirs_counter,
3431 				ext4_count_dirs(sb));
3432 	}
3433 	if (!err) {
3434 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3435 	}
3436 	if (err) {
3437 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3438 		goto failed_mount3;
3439 	}
3440 
3441 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3442 	sbi->s_max_writeback_mb_bump = 128;
3443 
3444 	/*
3445 	 * set up enough so that it can read an inode
3446 	 */
3447 	if (!test_opt(sb, NOLOAD) &&
3448 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3449 		sb->s_op = &ext4_sops;
3450 	else
3451 		sb->s_op = &ext4_nojournal_sops;
3452 	sb->s_export_op = &ext4_export_ops;
3453 	sb->s_xattr = ext4_xattr_handlers;
3454 #ifdef CONFIG_QUOTA
3455 	sb->s_qcop = &ext4_qctl_operations;
3456 	sb->dq_op = &ext4_quota_operations;
3457 #endif
3458 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3459 
3460 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3461 	mutex_init(&sbi->s_orphan_lock);
3462 	sbi->s_resize_flags = 0;
3463 
3464 	sb->s_root = NULL;
3465 
3466 	needs_recovery = (es->s_last_orphan != 0 ||
3467 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3468 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3469 
3470 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3471 	    !(sb->s_flags & MS_RDONLY))
3472 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3473 			goto failed_mount3;
3474 
3475 	/*
3476 	 * The first inode we look at is the journal inode.  Don't try
3477 	 * root first: it may be modified in the journal!
3478 	 */
3479 	if (!test_opt(sb, NOLOAD) &&
3480 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3481 		if (ext4_load_journal(sb, es, journal_devnum))
3482 			goto failed_mount3;
3483 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3484 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3485 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3486 		       "suppressed and not mounted read-only");
3487 		goto failed_mount_wq;
3488 	} else {
3489 		clear_opt(sb, DATA_FLAGS);
3490 		sbi->s_journal = NULL;
3491 		needs_recovery = 0;
3492 		goto no_journal;
3493 	}
3494 
3495 	if (ext4_blocks_count(es) > 0xffffffffULL &&
3496 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3497 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3498 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3499 		goto failed_mount_wq;
3500 	}
3501 
3502 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3503 		jbd2_journal_set_features(sbi->s_journal,
3504 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3505 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3506 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3507 		jbd2_journal_set_features(sbi->s_journal,
3508 				JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
3509 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3510 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3511 	} else {
3512 		jbd2_journal_clear_features(sbi->s_journal,
3513 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3514 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3515 	}
3516 
3517 	/* We have now updated the journal if required, so we can
3518 	 * validate the data journaling mode. */
3519 	switch (test_opt(sb, DATA_FLAGS)) {
3520 	case 0:
3521 		/* No mode set, assume a default based on the journal
3522 		 * capabilities: ORDERED_DATA if the journal can
3523 		 * cope, else JOURNAL_DATA
3524 		 */
3525 		if (jbd2_journal_check_available_features
3526 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3527 			set_opt(sb, ORDERED_DATA);
3528 		else
3529 			set_opt(sb, JOURNAL_DATA);
3530 		break;
3531 
3532 	case EXT4_MOUNT_ORDERED_DATA:
3533 	case EXT4_MOUNT_WRITEBACK_DATA:
3534 		if (!jbd2_journal_check_available_features
3535 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3536 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3537 			       "requested data journaling mode");
3538 			goto failed_mount_wq;
3539 		}
3540 	default:
3541 		break;
3542 	}
3543 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3544 
3545 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3546 
3547 	/*
3548 	 * The journal may have updated the bg summary counts, so we
3549 	 * need to update the global counters.
3550 	 */
3551 	percpu_counter_set(&sbi->s_freeclusters_counter,
3552 			   ext4_count_free_clusters(sb));
3553 	percpu_counter_set(&sbi->s_freeinodes_counter,
3554 			   ext4_count_free_inodes(sb));
3555 	percpu_counter_set(&sbi->s_dirs_counter,
3556 			   ext4_count_dirs(sb));
3557 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3558 
3559 no_journal:
3560 	/*
3561 	 * The maximum number of concurrent works can be high and
3562 	 * concurrency isn't really necessary.  Limit it to 1.
3563 	 */
3564 	EXT4_SB(sb)->dio_unwritten_wq =
3565 		alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3566 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3567 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3568 		goto failed_mount_wq;
3569 	}
3570 
3571 	/*
3572 	 * The jbd2_journal_load will have done any necessary log recovery,
3573 	 * so we can safely mount the rest of the filesystem now.
3574 	 */
3575 
3576 	root = ext4_iget(sb, EXT4_ROOT_INO);
3577 	if (IS_ERR(root)) {
3578 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3579 		ret = PTR_ERR(root);
3580 		root = NULL;
3581 		goto failed_mount4;
3582 	}
3583 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3584 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3585 		iput(root);
3586 		goto failed_mount4;
3587 	}
3588 	sb->s_root = d_make_root(root);
3589 	if (!sb->s_root) {
3590 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3591 		ret = -ENOMEM;
3592 		goto failed_mount4;
3593 	}
3594 
3595 	ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
3596 
3597 	/* determine the minimum size of new large inodes, if present */
3598 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3599 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3600 						     EXT4_GOOD_OLD_INODE_SIZE;
3601 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3602 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3603 			if (sbi->s_want_extra_isize <
3604 			    le16_to_cpu(es->s_want_extra_isize))
3605 				sbi->s_want_extra_isize =
3606 					le16_to_cpu(es->s_want_extra_isize);
3607 			if (sbi->s_want_extra_isize <
3608 			    le16_to_cpu(es->s_min_extra_isize))
3609 				sbi->s_want_extra_isize =
3610 					le16_to_cpu(es->s_min_extra_isize);
3611 		}
3612 	}
3613 	/* Check if enough inode space is available */
3614 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3615 							sbi->s_inode_size) {
3616 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3617 						       EXT4_GOOD_OLD_INODE_SIZE;
3618 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3619 			 "available");
3620 	}
3621 
3622 	err = ext4_setup_system_zone(sb);
3623 	if (err) {
3624 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3625 			 "zone (%d)", err);
3626 		goto failed_mount4a;
3627 	}
3628 
3629 	ext4_ext_init(sb);
3630 	err = ext4_mb_init(sb, needs_recovery);
3631 	if (err) {
3632 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3633 			 err);
3634 		goto failed_mount5;
3635 	}
3636 
3637 	err = ext4_register_li_request(sb, first_not_zeroed);
3638 	if (err)
3639 		goto failed_mount6;
3640 
3641 	sbi->s_kobj.kset = ext4_kset;
3642 	init_completion(&sbi->s_kobj_unregister);
3643 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3644 				   "%s", sb->s_id);
3645 	if (err)
3646 		goto failed_mount7;
3647 
3648 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3649 	ext4_orphan_cleanup(sb, es);
3650 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3651 	if (needs_recovery) {
3652 		ext4_msg(sb, KERN_INFO, "recovery complete");
3653 		ext4_mark_recovery_complete(sb, es);
3654 	}
3655 	if (EXT4_SB(sb)->s_journal) {
3656 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3657 			descr = " journalled data mode";
3658 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3659 			descr = " ordered data mode";
3660 		else
3661 			descr = " writeback data mode";
3662 	} else
3663 		descr = "out journal";
3664 
3665 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3666 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3667 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3668 
3669 	if (es->s_error_count)
3670 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3671 
3672 	kfree(orig_data);
3673 	return 0;
3674 
3675 cantfind_ext4:
3676 	if (!silent)
3677 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3678 	goto failed_mount;
3679 
3680 failed_mount7:
3681 	ext4_unregister_li_request(sb);
3682 failed_mount6:
3683 	ext4_mb_release(sb);
3684 failed_mount5:
3685 	ext4_ext_release(sb);
3686 	ext4_release_system_zone(sb);
3687 failed_mount4a:
3688 	dput(sb->s_root);
3689 	sb->s_root = NULL;
3690 failed_mount4:
3691 	ext4_msg(sb, KERN_ERR, "mount failed");
3692 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3693 failed_mount_wq:
3694 	if (sbi->s_journal) {
3695 		jbd2_journal_destroy(sbi->s_journal);
3696 		sbi->s_journal = NULL;
3697 	}
3698 failed_mount3:
3699 	del_timer(&sbi->s_err_report);
3700 	if (sbi->s_flex_groups)
3701 		ext4_kvfree(sbi->s_flex_groups);
3702 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
3703 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
3704 	percpu_counter_destroy(&sbi->s_dirs_counter);
3705 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
3706 	if (sbi->s_mmp_tsk)
3707 		kthread_stop(sbi->s_mmp_tsk);
3708 failed_mount2:
3709 	for (i = 0; i < db_count; i++)
3710 		brelse(sbi->s_group_desc[i]);
3711 	ext4_kvfree(sbi->s_group_desc);
3712 failed_mount:
3713 	if (sbi->s_proc) {
3714 		remove_proc_entry("options", sbi->s_proc);
3715 		remove_proc_entry(sb->s_id, ext4_proc_root);
3716 	}
3717 #ifdef CONFIG_QUOTA
3718 	for (i = 0; i < MAXQUOTAS; i++)
3719 		kfree(sbi->s_qf_names[i]);
3720 #endif
3721 	ext4_blkdev_remove(sbi);
3722 	brelse(bh);
3723 out_fail:
3724 	sb->s_fs_info = NULL;
3725 	kfree(sbi->s_blockgroup_lock);
3726 	kfree(sbi);
3727 out_free_orig:
3728 	kfree(orig_data);
3729 	return ret;
3730 }
3731 
3732 /*
3733  * Setup any per-fs journal parameters now.  We'll do this both on
3734  * initial mount, once the journal has been initialised but before we've
3735  * done any recovery; and again on any subsequent remount.
3736  */
3737 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3738 {
3739 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3740 
3741 	journal->j_commit_interval = sbi->s_commit_interval;
3742 	journal->j_min_batch_time = sbi->s_min_batch_time;
3743 	journal->j_max_batch_time = sbi->s_max_batch_time;
3744 
3745 	write_lock(&journal->j_state_lock);
3746 	if (test_opt(sb, BARRIER))
3747 		journal->j_flags |= JBD2_BARRIER;
3748 	else
3749 		journal->j_flags &= ~JBD2_BARRIER;
3750 	if (test_opt(sb, DATA_ERR_ABORT))
3751 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3752 	else
3753 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3754 	write_unlock(&journal->j_state_lock);
3755 }
3756 
3757 static journal_t *ext4_get_journal(struct super_block *sb,
3758 				   unsigned int journal_inum)
3759 {
3760 	struct inode *journal_inode;
3761 	journal_t *journal;
3762 
3763 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3764 
3765 	/* First, test for the existence of a valid inode on disk.  Bad
3766 	 * things happen if we iget() an unused inode, as the subsequent
3767 	 * iput() will try to delete it. */
3768 
3769 	journal_inode = ext4_iget(sb, journal_inum);
3770 	if (IS_ERR(journal_inode)) {
3771 		ext4_msg(sb, KERN_ERR, "no journal found");
3772 		return NULL;
3773 	}
3774 	if (!journal_inode->i_nlink) {
3775 		make_bad_inode(journal_inode);
3776 		iput(journal_inode);
3777 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3778 		return NULL;
3779 	}
3780 
3781 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3782 		  journal_inode, journal_inode->i_size);
3783 	if (!S_ISREG(journal_inode->i_mode)) {
3784 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
3785 		iput(journal_inode);
3786 		return NULL;
3787 	}
3788 
3789 	journal = jbd2_journal_init_inode(journal_inode);
3790 	if (!journal) {
3791 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3792 		iput(journal_inode);
3793 		return NULL;
3794 	}
3795 	journal->j_private = sb;
3796 	ext4_init_journal_params(sb, journal);
3797 	return journal;
3798 }
3799 
3800 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3801 				       dev_t j_dev)
3802 {
3803 	struct buffer_head *bh;
3804 	journal_t *journal;
3805 	ext4_fsblk_t start;
3806 	ext4_fsblk_t len;
3807 	int hblock, blocksize;
3808 	ext4_fsblk_t sb_block;
3809 	unsigned long offset;
3810 	struct ext4_super_block *es;
3811 	struct block_device *bdev;
3812 
3813 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3814 
3815 	bdev = ext4_blkdev_get(j_dev, sb);
3816 	if (bdev == NULL)
3817 		return NULL;
3818 
3819 	blocksize = sb->s_blocksize;
3820 	hblock = bdev_logical_block_size(bdev);
3821 	if (blocksize < hblock) {
3822 		ext4_msg(sb, KERN_ERR,
3823 			"blocksize too small for journal device");
3824 		goto out_bdev;
3825 	}
3826 
3827 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3828 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3829 	set_blocksize(bdev, blocksize);
3830 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
3831 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3832 		       "external journal");
3833 		goto out_bdev;
3834 	}
3835 
3836 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3837 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3838 	    !(le32_to_cpu(es->s_feature_incompat) &
3839 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3840 		ext4_msg(sb, KERN_ERR, "external journal has "
3841 					"bad superblock");
3842 		brelse(bh);
3843 		goto out_bdev;
3844 	}
3845 
3846 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3847 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3848 		brelse(bh);
3849 		goto out_bdev;
3850 	}
3851 
3852 	len = ext4_blocks_count(es);
3853 	start = sb_block + 1;
3854 	brelse(bh);	/* we're done with the superblock */
3855 
3856 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3857 					start, len, blocksize);
3858 	if (!journal) {
3859 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
3860 		goto out_bdev;
3861 	}
3862 	journal->j_private = sb;
3863 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
3864 	wait_on_buffer(journal->j_sb_buffer);
3865 	if (!buffer_uptodate(journal->j_sb_buffer)) {
3866 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3867 		goto out_journal;
3868 	}
3869 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3870 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
3871 					"user (unsupported) - %d",
3872 			be32_to_cpu(journal->j_superblock->s_nr_users));
3873 		goto out_journal;
3874 	}
3875 	EXT4_SB(sb)->journal_bdev = bdev;
3876 	ext4_init_journal_params(sb, journal);
3877 	return journal;
3878 
3879 out_journal:
3880 	jbd2_journal_destroy(journal);
3881 out_bdev:
3882 	ext4_blkdev_put(bdev);
3883 	return NULL;
3884 }
3885 
3886 static int ext4_load_journal(struct super_block *sb,
3887 			     struct ext4_super_block *es,
3888 			     unsigned long journal_devnum)
3889 {
3890 	journal_t *journal;
3891 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3892 	dev_t journal_dev;
3893 	int err = 0;
3894 	int really_read_only;
3895 
3896 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3897 
3898 	if (journal_devnum &&
3899 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3900 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3901 			"numbers have changed");
3902 		journal_dev = new_decode_dev(journal_devnum);
3903 	} else
3904 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3905 
3906 	really_read_only = bdev_read_only(sb->s_bdev);
3907 
3908 	/*
3909 	 * Are we loading a blank journal or performing recovery after a
3910 	 * crash?  For recovery, we need to check in advance whether we
3911 	 * can get read-write access to the device.
3912 	 */
3913 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3914 		if (sb->s_flags & MS_RDONLY) {
3915 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
3916 					"required on readonly filesystem");
3917 			if (really_read_only) {
3918 				ext4_msg(sb, KERN_ERR, "write access "
3919 					"unavailable, cannot proceed");
3920 				return -EROFS;
3921 			}
3922 			ext4_msg(sb, KERN_INFO, "write access will "
3923 			       "be enabled during recovery");
3924 		}
3925 	}
3926 
3927 	if (journal_inum && journal_dev) {
3928 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3929 		       "and inode journals!");
3930 		return -EINVAL;
3931 	}
3932 
3933 	if (journal_inum) {
3934 		if (!(journal = ext4_get_journal(sb, journal_inum)))
3935 			return -EINVAL;
3936 	} else {
3937 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3938 			return -EINVAL;
3939 	}
3940 
3941 	if (!(journal->j_flags & JBD2_BARRIER))
3942 		ext4_msg(sb, KERN_INFO, "barriers disabled");
3943 
3944 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3945 		err = jbd2_journal_wipe(journal, !really_read_only);
3946 	if (!err) {
3947 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
3948 		if (save)
3949 			memcpy(save, ((char *) es) +
3950 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
3951 		err = jbd2_journal_load(journal);
3952 		if (save)
3953 			memcpy(((char *) es) + EXT4_S_ERR_START,
3954 			       save, EXT4_S_ERR_LEN);
3955 		kfree(save);
3956 	}
3957 
3958 	if (err) {
3959 		ext4_msg(sb, KERN_ERR, "error loading journal");
3960 		jbd2_journal_destroy(journal);
3961 		return err;
3962 	}
3963 
3964 	EXT4_SB(sb)->s_journal = journal;
3965 	ext4_clear_journal_err(sb, es);
3966 
3967 	if (!really_read_only && journal_devnum &&
3968 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3969 		es->s_journal_dev = cpu_to_le32(journal_devnum);
3970 
3971 		/* Make sure we flush the recovery flag to disk. */
3972 		ext4_commit_super(sb, 1);
3973 	}
3974 
3975 	return 0;
3976 }
3977 
3978 static int ext4_commit_super(struct super_block *sb, int sync)
3979 {
3980 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3981 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3982 	int error = 0;
3983 
3984 	if (!sbh || block_device_ejected(sb))
3985 		return error;
3986 	if (buffer_write_io_error(sbh)) {
3987 		/*
3988 		 * Oh, dear.  A previous attempt to write the
3989 		 * superblock failed.  This could happen because the
3990 		 * USB device was yanked out.  Or it could happen to
3991 		 * be a transient write error and maybe the block will
3992 		 * be remapped.  Nothing we can do but to retry the
3993 		 * write and hope for the best.
3994 		 */
3995 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
3996 		       "superblock detected");
3997 		clear_buffer_write_io_error(sbh);
3998 		set_buffer_uptodate(sbh);
3999 	}
4000 	/*
4001 	 * If the file system is mounted read-only, don't update the
4002 	 * superblock write time.  This avoids updating the superblock
4003 	 * write time when we are mounting the root file system
4004 	 * read/only but we need to replay the journal; at that point,
4005 	 * for people who are east of GMT and who make their clock
4006 	 * tick in localtime for Windows bug-for-bug compatibility,
4007 	 * the clock is set in the future, and this will cause e2fsck
4008 	 * to complain and force a full file system check.
4009 	 */
4010 	if (!(sb->s_flags & MS_RDONLY))
4011 		es->s_wtime = cpu_to_le32(get_seconds());
4012 	if (sb->s_bdev->bd_part)
4013 		es->s_kbytes_written =
4014 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4015 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4016 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4017 	else
4018 		es->s_kbytes_written =
4019 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4020 	ext4_free_blocks_count_set(es,
4021 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4022 				&EXT4_SB(sb)->s_freeclusters_counter)));
4023 	es->s_free_inodes_count =
4024 		cpu_to_le32(percpu_counter_sum_positive(
4025 				&EXT4_SB(sb)->s_freeinodes_counter));
4026 	sb->s_dirt = 0;
4027 	BUFFER_TRACE(sbh, "marking dirty");
4028 	mark_buffer_dirty(sbh);
4029 	if (sync) {
4030 		error = sync_dirty_buffer(sbh);
4031 		if (error)
4032 			return error;
4033 
4034 		error = buffer_write_io_error(sbh);
4035 		if (error) {
4036 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4037 			       "superblock");
4038 			clear_buffer_write_io_error(sbh);
4039 			set_buffer_uptodate(sbh);
4040 		}
4041 	}
4042 	return error;
4043 }
4044 
4045 /*
4046  * Have we just finished recovery?  If so, and if we are mounting (or
4047  * remounting) the filesystem readonly, then we will end up with a
4048  * consistent fs on disk.  Record that fact.
4049  */
4050 static void ext4_mark_recovery_complete(struct super_block *sb,
4051 					struct ext4_super_block *es)
4052 {
4053 	journal_t *journal = EXT4_SB(sb)->s_journal;
4054 
4055 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4056 		BUG_ON(journal != NULL);
4057 		return;
4058 	}
4059 	jbd2_journal_lock_updates(journal);
4060 	if (jbd2_journal_flush(journal) < 0)
4061 		goto out;
4062 
4063 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4064 	    sb->s_flags & MS_RDONLY) {
4065 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4066 		ext4_commit_super(sb, 1);
4067 	}
4068 
4069 out:
4070 	jbd2_journal_unlock_updates(journal);
4071 }
4072 
4073 /*
4074  * If we are mounting (or read-write remounting) a filesystem whose journal
4075  * has recorded an error from a previous lifetime, move that error to the
4076  * main filesystem now.
4077  */
4078 static void ext4_clear_journal_err(struct super_block *sb,
4079 				   struct ext4_super_block *es)
4080 {
4081 	journal_t *journal;
4082 	int j_errno;
4083 	const char *errstr;
4084 
4085 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4086 
4087 	journal = EXT4_SB(sb)->s_journal;
4088 
4089 	/*
4090 	 * Now check for any error status which may have been recorded in the
4091 	 * journal by a prior ext4_error() or ext4_abort()
4092 	 */
4093 
4094 	j_errno = jbd2_journal_errno(journal);
4095 	if (j_errno) {
4096 		char nbuf[16];
4097 
4098 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4099 		ext4_warning(sb, "Filesystem error recorded "
4100 			     "from previous mount: %s", errstr);
4101 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4102 
4103 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4104 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4105 		ext4_commit_super(sb, 1);
4106 
4107 		jbd2_journal_clear_err(journal);
4108 	}
4109 }
4110 
4111 /*
4112  * Force the running and committing transactions to commit,
4113  * and wait on the commit.
4114  */
4115 int ext4_force_commit(struct super_block *sb)
4116 {
4117 	journal_t *journal;
4118 	int ret = 0;
4119 
4120 	if (sb->s_flags & MS_RDONLY)
4121 		return 0;
4122 
4123 	journal = EXT4_SB(sb)->s_journal;
4124 	if (journal) {
4125 		vfs_check_frozen(sb, SB_FREEZE_TRANS);
4126 		ret = ext4_journal_force_commit(journal);
4127 	}
4128 
4129 	return ret;
4130 }
4131 
4132 static void ext4_write_super(struct super_block *sb)
4133 {
4134 	lock_super(sb);
4135 	ext4_commit_super(sb, 1);
4136 	unlock_super(sb);
4137 }
4138 
4139 static int ext4_sync_fs(struct super_block *sb, int wait)
4140 {
4141 	int ret = 0;
4142 	tid_t target;
4143 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4144 
4145 	trace_ext4_sync_fs(sb, wait);
4146 	flush_workqueue(sbi->dio_unwritten_wq);
4147 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4148 		if (wait)
4149 			jbd2_log_wait_commit(sbi->s_journal, target);
4150 	}
4151 	return ret;
4152 }
4153 
4154 /*
4155  * LVM calls this function before a (read-only) snapshot is created.  This
4156  * gives us a chance to flush the journal completely and mark the fs clean.
4157  *
4158  * Note that only this function cannot bring a filesystem to be in a clean
4159  * state independently, because ext4 prevents a new handle from being started
4160  * by @sb->s_frozen, which stays in an upper layer.  It thus needs help from
4161  * the upper layer.
4162  */
4163 static int ext4_freeze(struct super_block *sb)
4164 {
4165 	int error = 0;
4166 	journal_t *journal;
4167 
4168 	if (sb->s_flags & MS_RDONLY)
4169 		return 0;
4170 
4171 	journal = EXT4_SB(sb)->s_journal;
4172 
4173 	/* Now we set up the journal barrier. */
4174 	jbd2_journal_lock_updates(journal);
4175 
4176 	/*
4177 	 * Don't clear the needs_recovery flag if we failed to flush
4178 	 * the journal.
4179 	 */
4180 	error = jbd2_journal_flush(journal);
4181 	if (error < 0)
4182 		goto out;
4183 
4184 	/* Journal blocked and flushed, clear needs_recovery flag. */
4185 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4186 	error = ext4_commit_super(sb, 1);
4187 out:
4188 	/* we rely on s_frozen to stop further updates */
4189 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4190 	return error;
4191 }
4192 
4193 /*
4194  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4195  * flag here, even though the filesystem is not technically dirty yet.
4196  */
4197 static int ext4_unfreeze(struct super_block *sb)
4198 {
4199 	if (sb->s_flags & MS_RDONLY)
4200 		return 0;
4201 
4202 	lock_super(sb);
4203 	/* Reset the needs_recovery flag before the fs is unlocked. */
4204 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4205 	ext4_commit_super(sb, 1);
4206 	unlock_super(sb);
4207 	return 0;
4208 }
4209 
4210 /*
4211  * Structure to save mount options for ext4_remount's benefit
4212  */
4213 struct ext4_mount_options {
4214 	unsigned long s_mount_opt;
4215 	unsigned long s_mount_opt2;
4216 	uid_t s_resuid;
4217 	gid_t s_resgid;
4218 	unsigned long s_commit_interval;
4219 	u32 s_min_batch_time, s_max_batch_time;
4220 #ifdef CONFIG_QUOTA
4221 	int s_jquota_fmt;
4222 	char *s_qf_names[MAXQUOTAS];
4223 #endif
4224 };
4225 
4226 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4227 {
4228 	struct ext4_super_block *es;
4229 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4230 	unsigned long old_sb_flags;
4231 	struct ext4_mount_options old_opts;
4232 	int enable_quota = 0;
4233 	ext4_group_t g;
4234 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4235 	int err = 0;
4236 #ifdef CONFIG_QUOTA
4237 	int i;
4238 #endif
4239 	char *orig_data = kstrdup(data, GFP_KERNEL);
4240 
4241 	/* Store the original options */
4242 	lock_super(sb);
4243 	old_sb_flags = sb->s_flags;
4244 	old_opts.s_mount_opt = sbi->s_mount_opt;
4245 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4246 	old_opts.s_resuid = sbi->s_resuid;
4247 	old_opts.s_resgid = sbi->s_resgid;
4248 	old_opts.s_commit_interval = sbi->s_commit_interval;
4249 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4250 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4251 #ifdef CONFIG_QUOTA
4252 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4253 	for (i = 0; i < MAXQUOTAS; i++)
4254 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4255 #endif
4256 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4257 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4258 
4259 	/*
4260 	 * Allow the "check" option to be passed as a remount option.
4261 	 */
4262 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4263 		err = -EINVAL;
4264 		goto restore_opts;
4265 	}
4266 
4267 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4268 		ext4_abort(sb, "Abort forced by user");
4269 
4270 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4271 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4272 
4273 	es = sbi->s_es;
4274 
4275 	if (sbi->s_journal) {
4276 		ext4_init_journal_params(sb, sbi->s_journal);
4277 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4278 	}
4279 
4280 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4281 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4282 			err = -EROFS;
4283 			goto restore_opts;
4284 		}
4285 
4286 		if (*flags & MS_RDONLY) {
4287 			err = dquot_suspend(sb, -1);
4288 			if (err < 0)
4289 				goto restore_opts;
4290 
4291 			/*
4292 			 * First of all, the unconditional stuff we have to do
4293 			 * to disable replay of the journal when we next remount
4294 			 */
4295 			sb->s_flags |= MS_RDONLY;
4296 
4297 			/*
4298 			 * OK, test if we are remounting a valid rw partition
4299 			 * readonly, and if so set the rdonly flag and then
4300 			 * mark the partition as valid again.
4301 			 */
4302 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4303 			    (sbi->s_mount_state & EXT4_VALID_FS))
4304 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4305 
4306 			if (sbi->s_journal)
4307 				ext4_mark_recovery_complete(sb, es);
4308 		} else {
4309 			/* Make sure we can mount this feature set readwrite */
4310 			if (!ext4_feature_set_ok(sb, 0)) {
4311 				err = -EROFS;
4312 				goto restore_opts;
4313 			}
4314 			/*
4315 			 * Make sure the group descriptor checksums
4316 			 * are sane.  If they aren't, refuse to remount r/w.
4317 			 */
4318 			for (g = 0; g < sbi->s_groups_count; g++) {
4319 				struct ext4_group_desc *gdp =
4320 					ext4_get_group_desc(sb, g, NULL);
4321 
4322 				if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
4323 					ext4_msg(sb, KERN_ERR,
4324 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4325 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4326 					       le16_to_cpu(gdp->bg_checksum));
4327 					err = -EINVAL;
4328 					goto restore_opts;
4329 				}
4330 			}
4331 
4332 			/*
4333 			 * If we have an unprocessed orphan list hanging
4334 			 * around from a previously readonly bdev mount,
4335 			 * require a full umount/remount for now.
4336 			 */
4337 			if (es->s_last_orphan) {
4338 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4339 				       "remount RDWR because of unprocessed "
4340 				       "orphan inode list.  Please "
4341 				       "umount/remount instead");
4342 				err = -EINVAL;
4343 				goto restore_opts;
4344 			}
4345 
4346 			/*
4347 			 * Mounting a RDONLY partition read-write, so reread
4348 			 * and store the current valid flag.  (It may have
4349 			 * been changed by e2fsck since we originally mounted
4350 			 * the partition.)
4351 			 */
4352 			if (sbi->s_journal)
4353 				ext4_clear_journal_err(sb, es);
4354 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4355 			if (!ext4_setup_super(sb, es, 0))
4356 				sb->s_flags &= ~MS_RDONLY;
4357 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4358 						     EXT4_FEATURE_INCOMPAT_MMP))
4359 				if (ext4_multi_mount_protect(sb,
4360 						le64_to_cpu(es->s_mmp_block))) {
4361 					err = -EROFS;
4362 					goto restore_opts;
4363 				}
4364 			enable_quota = 1;
4365 		}
4366 	}
4367 
4368 	/*
4369 	 * Reinitialize lazy itable initialization thread based on
4370 	 * current settings
4371 	 */
4372 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4373 		ext4_unregister_li_request(sb);
4374 	else {
4375 		ext4_group_t first_not_zeroed;
4376 		first_not_zeroed = ext4_has_uninit_itable(sb);
4377 		ext4_register_li_request(sb, first_not_zeroed);
4378 	}
4379 
4380 	ext4_setup_system_zone(sb);
4381 	if (sbi->s_journal == NULL)
4382 		ext4_commit_super(sb, 1);
4383 
4384 #ifdef CONFIG_QUOTA
4385 	/* Release old quota file names */
4386 	for (i = 0; i < MAXQUOTAS; i++)
4387 		if (old_opts.s_qf_names[i] &&
4388 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4389 			kfree(old_opts.s_qf_names[i]);
4390 #endif
4391 	unlock_super(sb);
4392 	if (enable_quota)
4393 		dquot_resume(sb, -1);
4394 
4395 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4396 	kfree(orig_data);
4397 	return 0;
4398 
4399 restore_opts:
4400 	sb->s_flags = old_sb_flags;
4401 	sbi->s_mount_opt = old_opts.s_mount_opt;
4402 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4403 	sbi->s_resuid = old_opts.s_resuid;
4404 	sbi->s_resgid = old_opts.s_resgid;
4405 	sbi->s_commit_interval = old_opts.s_commit_interval;
4406 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4407 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4408 #ifdef CONFIG_QUOTA
4409 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4410 	for (i = 0; i < MAXQUOTAS; i++) {
4411 		if (sbi->s_qf_names[i] &&
4412 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4413 			kfree(sbi->s_qf_names[i]);
4414 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4415 	}
4416 #endif
4417 	unlock_super(sb);
4418 	kfree(orig_data);
4419 	return err;
4420 }
4421 
4422 /*
4423  * Note: calculating the overhead so we can be compatible with
4424  * historical BSD practice is quite difficult in the face of
4425  * clusters/bigalloc.  This is because multiple metadata blocks from
4426  * different block group can end up in the same allocation cluster.
4427  * Calculating the exact overhead in the face of clustered allocation
4428  * requires either O(all block bitmaps) in memory or O(number of block
4429  * groups**2) in time.  We will still calculate the superblock for
4430  * older file systems --- and if we come across with a bigalloc file
4431  * system with zero in s_overhead_clusters the estimate will be close to
4432  * correct especially for very large cluster sizes --- but for newer
4433  * file systems, it's better to calculate this figure once at mkfs
4434  * time, and store it in the superblock.  If the superblock value is
4435  * present (even for non-bigalloc file systems), we will use it.
4436  */
4437 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4438 {
4439 	struct super_block *sb = dentry->d_sb;
4440 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4441 	struct ext4_super_block *es = sbi->s_es;
4442 	struct ext4_group_desc *gdp;
4443 	u64 fsid;
4444 	s64 bfree;
4445 
4446 	if (test_opt(sb, MINIX_DF)) {
4447 		sbi->s_overhead_last = 0;
4448 	} else if (es->s_overhead_clusters) {
4449 		sbi->s_overhead_last = le32_to_cpu(es->s_overhead_clusters);
4450 	} else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
4451 		ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4452 		ext4_fsblk_t overhead = 0;
4453 
4454 		/*
4455 		 * Compute the overhead (FS structures).  This is constant
4456 		 * for a given filesystem unless the number of block groups
4457 		 * changes so we cache the previous value until it does.
4458 		 */
4459 
4460 		/*
4461 		 * All of the blocks before first_data_block are
4462 		 * overhead
4463 		 */
4464 		overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
4465 
4466 		/*
4467 		 * Add the overhead found in each block group
4468 		 */
4469 		for (i = 0; i < ngroups; i++) {
4470 			gdp = ext4_get_group_desc(sb, i, NULL);
4471 			overhead += ext4_num_overhead_clusters(sb, i, gdp);
4472 			cond_resched();
4473 		}
4474 		sbi->s_overhead_last = overhead;
4475 		smp_wmb();
4476 		sbi->s_blocks_last = ext4_blocks_count(es);
4477 	}
4478 
4479 	buf->f_type = EXT4_SUPER_MAGIC;
4480 	buf->f_bsize = sb->s_blocksize;
4481 	buf->f_blocks = (ext4_blocks_count(es) -
4482 			 EXT4_C2B(sbi, sbi->s_overhead_last));
4483 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4484 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4485 	/* prevent underflow in case that few free space is available */
4486 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4487 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4488 	if (buf->f_bfree < ext4_r_blocks_count(es))
4489 		buf->f_bavail = 0;
4490 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4491 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4492 	buf->f_namelen = EXT4_NAME_LEN;
4493 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4494 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4495 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4496 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4497 
4498 	return 0;
4499 }
4500 
4501 /* Helper function for writing quotas on sync - we need to start transaction
4502  * before quota file is locked for write. Otherwise the are possible deadlocks:
4503  * Process 1                         Process 2
4504  * ext4_create()                     quota_sync()
4505  *   jbd2_journal_start()                  write_dquot()
4506  *   dquot_initialize()                         down(dqio_mutex)
4507  *     down(dqio_mutex)                    jbd2_journal_start()
4508  *
4509  */
4510 
4511 #ifdef CONFIG_QUOTA
4512 
4513 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4514 {
4515 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4516 }
4517 
4518 static int ext4_write_dquot(struct dquot *dquot)
4519 {
4520 	int ret, err;
4521 	handle_t *handle;
4522 	struct inode *inode;
4523 
4524 	inode = dquot_to_inode(dquot);
4525 	handle = ext4_journal_start(inode,
4526 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4527 	if (IS_ERR(handle))
4528 		return PTR_ERR(handle);
4529 	ret = dquot_commit(dquot);
4530 	err = ext4_journal_stop(handle);
4531 	if (!ret)
4532 		ret = err;
4533 	return ret;
4534 }
4535 
4536 static int ext4_acquire_dquot(struct dquot *dquot)
4537 {
4538 	int ret, err;
4539 	handle_t *handle;
4540 
4541 	handle = ext4_journal_start(dquot_to_inode(dquot),
4542 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4543 	if (IS_ERR(handle))
4544 		return PTR_ERR(handle);
4545 	ret = dquot_acquire(dquot);
4546 	err = ext4_journal_stop(handle);
4547 	if (!ret)
4548 		ret = err;
4549 	return ret;
4550 }
4551 
4552 static int ext4_release_dquot(struct dquot *dquot)
4553 {
4554 	int ret, err;
4555 	handle_t *handle;
4556 
4557 	handle = ext4_journal_start(dquot_to_inode(dquot),
4558 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4559 	if (IS_ERR(handle)) {
4560 		/* Release dquot anyway to avoid endless cycle in dqput() */
4561 		dquot_release(dquot);
4562 		return PTR_ERR(handle);
4563 	}
4564 	ret = dquot_release(dquot);
4565 	err = ext4_journal_stop(handle);
4566 	if (!ret)
4567 		ret = err;
4568 	return ret;
4569 }
4570 
4571 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4572 {
4573 	/* Are we journaling quotas? */
4574 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4575 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4576 		dquot_mark_dquot_dirty(dquot);
4577 		return ext4_write_dquot(dquot);
4578 	} else {
4579 		return dquot_mark_dquot_dirty(dquot);
4580 	}
4581 }
4582 
4583 static int ext4_write_info(struct super_block *sb, int type)
4584 {
4585 	int ret, err;
4586 	handle_t *handle;
4587 
4588 	/* Data block + inode block */
4589 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
4590 	if (IS_ERR(handle))
4591 		return PTR_ERR(handle);
4592 	ret = dquot_commit_info(sb, type);
4593 	err = ext4_journal_stop(handle);
4594 	if (!ret)
4595 		ret = err;
4596 	return ret;
4597 }
4598 
4599 /*
4600  * Turn on quotas during mount time - we need to find
4601  * the quota file and such...
4602  */
4603 static int ext4_quota_on_mount(struct super_block *sb, int type)
4604 {
4605 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4606 					EXT4_SB(sb)->s_jquota_fmt, type);
4607 }
4608 
4609 /*
4610  * Standard function to be called on quota_on
4611  */
4612 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4613 			 struct path *path)
4614 {
4615 	int err;
4616 
4617 	if (!test_opt(sb, QUOTA))
4618 		return -EINVAL;
4619 
4620 	/* Quotafile not on the same filesystem? */
4621 	if (path->dentry->d_sb != sb)
4622 		return -EXDEV;
4623 	/* Journaling quota? */
4624 	if (EXT4_SB(sb)->s_qf_names[type]) {
4625 		/* Quotafile not in fs root? */
4626 		if (path->dentry->d_parent != sb->s_root)
4627 			ext4_msg(sb, KERN_WARNING,
4628 				"Quota file not on filesystem root. "
4629 				"Journaled quota will not work");
4630 	}
4631 
4632 	/*
4633 	 * When we journal data on quota file, we have to flush journal to see
4634 	 * all updates to the file when we bypass pagecache...
4635 	 */
4636 	if (EXT4_SB(sb)->s_journal &&
4637 	    ext4_should_journal_data(path->dentry->d_inode)) {
4638 		/*
4639 		 * We don't need to lock updates but journal_flush() could
4640 		 * otherwise be livelocked...
4641 		 */
4642 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4643 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4644 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4645 		if (err)
4646 			return err;
4647 	}
4648 
4649 	return dquot_quota_on(sb, type, format_id, path);
4650 }
4651 
4652 static int ext4_quota_off(struct super_block *sb, int type)
4653 {
4654 	struct inode *inode = sb_dqopt(sb)->files[type];
4655 	handle_t *handle;
4656 
4657 	/* Force all delayed allocation blocks to be allocated.
4658 	 * Caller already holds s_umount sem */
4659 	if (test_opt(sb, DELALLOC))
4660 		sync_filesystem(sb);
4661 
4662 	if (!inode)
4663 		goto out;
4664 
4665 	/* Update modification times of quota files when userspace can
4666 	 * start looking at them */
4667 	handle = ext4_journal_start(inode, 1);
4668 	if (IS_ERR(handle))
4669 		goto out;
4670 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4671 	ext4_mark_inode_dirty(handle, inode);
4672 	ext4_journal_stop(handle);
4673 
4674 out:
4675 	return dquot_quota_off(sb, type);
4676 }
4677 
4678 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4679  * acquiring the locks... As quota files are never truncated and quota code
4680  * itself serializes the operations (and no one else should touch the files)
4681  * we don't have to be afraid of races */
4682 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4683 			       size_t len, loff_t off)
4684 {
4685 	struct inode *inode = sb_dqopt(sb)->files[type];
4686 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4687 	int err = 0;
4688 	int offset = off & (sb->s_blocksize - 1);
4689 	int tocopy;
4690 	size_t toread;
4691 	struct buffer_head *bh;
4692 	loff_t i_size = i_size_read(inode);
4693 
4694 	if (off > i_size)
4695 		return 0;
4696 	if (off+len > i_size)
4697 		len = i_size-off;
4698 	toread = len;
4699 	while (toread > 0) {
4700 		tocopy = sb->s_blocksize - offset < toread ?
4701 				sb->s_blocksize - offset : toread;
4702 		bh = ext4_bread(NULL, inode, blk, 0, &err);
4703 		if (err)
4704 			return err;
4705 		if (!bh)	/* A hole? */
4706 			memset(data, 0, tocopy);
4707 		else
4708 			memcpy(data, bh->b_data+offset, tocopy);
4709 		brelse(bh);
4710 		offset = 0;
4711 		toread -= tocopy;
4712 		data += tocopy;
4713 		blk++;
4714 	}
4715 	return len;
4716 }
4717 
4718 /* Write to quotafile (we know the transaction is already started and has
4719  * enough credits) */
4720 static ssize_t ext4_quota_write(struct super_block *sb, int type,
4721 				const char *data, size_t len, loff_t off)
4722 {
4723 	struct inode *inode = sb_dqopt(sb)->files[type];
4724 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4725 	int err = 0;
4726 	int offset = off & (sb->s_blocksize - 1);
4727 	struct buffer_head *bh;
4728 	handle_t *handle = journal_current_handle();
4729 
4730 	if (EXT4_SB(sb)->s_journal && !handle) {
4731 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4732 			" cancelled because transaction is not started",
4733 			(unsigned long long)off, (unsigned long long)len);
4734 		return -EIO;
4735 	}
4736 	/*
4737 	 * Since we account only one data block in transaction credits,
4738 	 * then it is impossible to cross a block boundary.
4739 	 */
4740 	if (sb->s_blocksize - offset < len) {
4741 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4742 			" cancelled because not block aligned",
4743 			(unsigned long long)off, (unsigned long long)len);
4744 		return -EIO;
4745 	}
4746 
4747 	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
4748 	bh = ext4_bread(handle, inode, blk, 1, &err);
4749 	if (!bh)
4750 		goto out;
4751 	err = ext4_journal_get_write_access(handle, bh);
4752 	if (err) {
4753 		brelse(bh);
4754 		goto out;
4755 	}
4756 	lock_buffer(bh);
4757 	memcpy(bh->b_data+offset, data, len);
4758 	flush_dcache_page(bh->b_page);
4759 	unlock_buffer(bh);
4760 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
4761 	brelse(bh);
4762 out:
4763 	if (err) {
4764 		mutex_unlock(&inode->i_mutex);
4765 		return err;
4766 	}
4767 	if (inode->i_size < off + len) {
4768 		i_size_write(inode, off + len);
4769 		EXT4_I(inode)->i_disksize = inode->i_size;
4770 		ext4_mark_inode_dirty(handle, inode);
4771 	}
4772 	mutex_unlock(&inode->i_mutex);
4773 	return len;
4774 }
4775 
4776 #endif
4777 
4778 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
4779 		       const char *dev_name, void *data)
4780 {
4781 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
4782 }
4783 
4784 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4785 static inline void register_as_ext2(void)
4786 {
4787 	int err = register_filesystem(&ext2_fs_type);
4788 	if (err)
4789 		printk(KERN_WARNING
4790 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4791 }
4792 
4793 static inline void unregister_as_ext2(void)
4794 {
4795 	unregister_filesystem(&ext2_fs_type);
4796 }
4797 
4798 static inline int ext2_feature_set_ok(struct super_block *sb)
4799 {
4800 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
4801 		return 0;
4802 	if (sb->s_flags & MS_RDONLY)
4803 		return 1;
4804 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
4805 		return 0;
4806 	return 1;
4807 }
4808 MODULE_ALIAS("ext2");
4809 #else
4810 static inline void register_as_ext2(void) { }
4811 static inline void unregister_as_ext2(void) { }
4812 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
4813 #endif
4814 
4815 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4816 static inline void register_as_ext3(void)
4817 {
4818 	int err = register_filesystem(&ext3_fs_type);
4819 	if (err)
4820 		printk(KERN_WARNING
4821 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4822 }
4823 
4824 static inline void unregister_as_ext3(void)
4825 {
4826 	unregister_filesystem(&ext3_fs_type);
4827 }
4828 
4829 static inline int ext3_feature_set_ok(struct super_block *sb)
4830 {
4831 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
4832 		return 0;
4833 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
4834 		return 0;
4835 	if (sb->s_flags & MS_RDONLY)
4836 		return 1;
4837 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
4838 		return 0;
4839 	return 1;
4840 }
4841 MODULE_ALIAS("ext3");
4842 #else
4843 static inline void register_as_ext3(void) { }
4844 static inline void unregister_as_ext3(void) { }
4845 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
4846 #endif
4847 
4848 static struct file_system_type ext4_fs_type = {
4849 	.owner		= THIS_MODULE,
4850 	.name		= "ext4",
4851 	.mount		= ext4_mount,
4852 	.kill_sb	= kill_block_super,
4853 	.fs_flags	= FS_REQUIRES_DEV,
4854 };
4855 
4856 static int __init ext4_init_feat_adverts(void)
4857 {
4858 	struct ext4_features *ef;
4859 	int ret = -ENOMEM;
4860 
4861 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
4862 	if (!ef)
4863 		goto out;
4864 
4865 	ef->f_kobj.kset = ext4_kset;
4866 	init_completion(&ef->f_kobj_unregister);
4867 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
4868 				   "features");
4869 	if (ret) {
4870 		kfree(ef);
4871 		goto out;
4872 	}
4873 
4874 	ext4_feat = ef;
4875 	ret = 0;
4876 out:
4877 	return ret;
4878 }
4879 
4880 static void ext4_exit_feat_adverts(void)
4881 {
4882 	kobject_put(&ext4_feat->f_kobj);
4883 	wait_for_completion(&ext4_feat->f_kobj_unregister);
4884 	kfree(ext4_feat);
4885 }
4886 
4887 /* Shared across all ext4 file systems */
4888 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
4889 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
4890 
4891 static int __init ext4_init_fs(void)
4892 {
4893 	int i, err;
4894 
4895 	ext4_li_info = NULL;
4896 	mutex_init(&ext4_li_mtx);
4897 
4898 	ext4_check_flag_values();
4899 
4900 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
4901 		mutex_init(&ext4__aio_mutex[i]);
4902 		init_waitqueue_head(&ext4__ioend_wq[i]);
4903 	}
4904 
4905 	err = ext4_init_pageio();
4906 	if (err)
4907 		return err;
4908 	err = ext4_init_system_zone();
4909 	if (err)
4910 		goto out6;
4911 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
4912 	if (!ext4_kset)
4913 		goto out5;
4914 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
4915 
4916 	err = ext4_init_feat_adverts();
4917 	if (err)
4918 		goto out4;
4919 
4920 	err = ext4_init_mballoc();
4921 	if (err)
4922 		goto out3;
4923 
4924 	err = ext4_init_xattr();
4925 	if (err)
4926 		goto out2;
4927 	err = init_inodecache();
4928 	if (err)
4929 		goto out1;
4930 	register_as_ext3();
4931 	register_as_ext2();
4932 	err = register_filesystem(&ext4_fs_type);
4933 	if (err)
4934 		goto out;
4935 
4936 	return 0;
4937 out:
4938 	unregister_as_ext2();
4939 	unregister_as_ext3();
4940 	destroy_inodecache();
4941 out1:
4942 	ext4_exit_xattr();
4943 out2:
4944 	ext4_exit_mballoc();
4945 out3:
4946 	ext4_exit_feat_adverts();
4947 out4:
4948 	if (ext4_proc_root)
4949 		remove_proc_entry("fs/ext4", NULL);
4950 	kset_unregister(ext4_kset);
4951 out5:
4952 	ext4_exit_system_zone();
4953 out6:
4954 	ext4_exit_pageio();
4955 	return err;
4956 }
4957 
4958 static void __exit ext4_exit_fs(void)
4959 {
4960 	ext4_destroy_lazyinit_thread();
4961 	unregister_as_ext2();
4962 	unregister_as_ext3();
4963 	unregister_filesystem(&ext4_fs_type);
4964 	destroy_inodecache();
4965 	ext4_exit_xattr();
4966 	ext4_exit_mballoc();
4967 	ext4_exit_feat_adverts();
4968 	remove_proc_entry("fs/ext4", NULL);
4969 	kset_unregister(ext4_kset);
4970 	ext4_exit_system_zone();
4971 	ext4_exit_pageio();
4972 }
4973 
4974 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4975 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4976 MODULE_LICENSE("GPL");
4977 module_init(ext4_init_fs)
4978 module_exit(ext4_exit_fs)
4979