xref: /linux/fs/ext4/super.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"	/* Needed for trace points definition */
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62 
63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
64 			     unsigned long journal_devnum);
65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
66 static int ext4_commit_super(struct super_block *sb, int sync);
67 static void ext4_mark_recovery_complete(struct super_block *sb,
68 					struct ext4_super_block *es);
69 static void ext4_clear_journal_err(struct super_block *sb,
70 				   struct ext4_super_block *es);
71 static int ext4_sync_fs(struct super_block *sb, int wait);
72 static 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 int ext4_freeze(struct super_block *sb);
78 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
79 		       const char *dev_name, void *data);
80 static inline int ext2_feature_set_ok(struct super_block *sb);
81 static inline int ext3_feature_set_ok(struct super_block *sb);
82 static int ext4_feature_set_ok(struct super_block *sb, int readonly);
83 static void ext4_destroy_lazyinit_thread(void);
84 static void ext4_unregister_li_request(struct super_block *sb);
85 static void ext4_clear_request_list(void);
86 
87 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
88 static struct file_system_type ext2_fs_type = {
89 	.owner		= THIS_MODULE,
90 	.name		= "ext2",
91 	.mount		= ext4_mount,
92 	.kill_sb	= kill_block_super,
93 	.fs_flags	= FS_REQUIRES_DEV,
94 };
95 #define IS_EXT2_SB(sb) ((sb)->s_bdev->bd_holder == &ext2_fs_type)
96 #else
97 #define IS_EXT2_SB(sb) (0)
98 #endif
99 
100 
101 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
102 static struct file_system_type ext3_fs_type = {
103 	.owner		= THIS_MODULE,
104 	.name		= "ext3",
105 	.mount		= ext4_mount,
106 	.kill_sb	= kill_block_super,
107 	.fs_flags	= FS_REQUIRES_DEV,
108 };
109 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
110 #else
111 #define IS_EXT3_SB(sb) (0)
112 #endif
113 
114 static int ext4_verify_csum_type(struct super_block *sb,
115 				 struct ext4_super_block *es)
116 {
117 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
118 					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
119 		return 1;
120 
121 	return es->s_checksum_type == EXT4_CRC32C_CHKSUM;
122 }
123 
124 static __le32 ext4_superblock_csum(struct super_block *sb,
125 				   struct ext4_super_block *es)
126 {
127 	struct ext4_sb_info *sbi = EXT4_SB(sb);
128 	int offset = offsetof(struct ext4_super_block, s_checksum);
129 	__u32 csum;
130 
131 	csum = ext4_chksum(sbi, ~0, (char *)es, offset);
132 
133 	return cpu_to_le32(csum);
134 }
135 
136 int ext4_superblock_csum_verify(struct super_block *sb,
137 				struct ext4_super_block *es)
138 {
139 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
140 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
141 		return 1;
142 
143 	return es->s_checksum == ext4_superblock_csum(sb, es);
144 }
145 
146 void ext4_superblock_csum_set(struct super_block *sb)
147 {
148 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
149 
150 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
151 		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
152 		return;
153 
154 	es->s_checksum = ext4_superblock_csum(sb, es);
155 }
156 
157 void *ext4_kvmalloc(size_t size, gfp_t flags)
158 {
159 	void *ret;
160 
161 	ret = kmalloc(size, flags);
162 	if (!ret)
163 		ret = __vmalloc(size, flags, PAGE_KERNEL);
164 	return ret;
165 }
166 
167 void *ext4_kvzalloc(size_t size, gfp_t flags)
168 {
169 	void *ret;
170 
171 	ret = kzalloc(size, flags);
172 	if (!ret)
173 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
174 	return ret;
175 }
176 
177 void ext4_kvfree(void *ptr)
178 {
179 	if (is_vmalloc_addr(ptr))
180 		vfree(ptr);
181 	else
182 		kfree(ptr);
183 
184 }
185 
186 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
187 			       struct ext4_group_desc *bg)
188 {
189 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
190 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
191 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
192 }
193 
194 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
195 			       struct ext4_group_desc *bg)
196 {
197 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
198 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
199 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
200 }
201 
202 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
203 			      struct ext4_group_desc *bg)
204 {
205 	return le32_to_cpu(bg->bg_inode_table_lo) |
206 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
207 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
208 }
209 
210 __u32 ext4_free_group_clusters(struct super_block *sb,
211 			       struct ext4_group_desc *bg)
212 {
213 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
214 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
215 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
216 }
217 
218 __u32 ext4_free_inodes_count(struct super_block *sb,
219 			      struct ext4_group_desc *bg)
220 {
221 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
222 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
223 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
224 }
225 
226 __u32 ext4_used_dirs_count(struct super_block *sb,
227 			      struct ext4_group_desc *bg)
228 {
229 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
230 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
231 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
232 }
233 
234 __u32 ext4_itable_unused_count(struct super_block *sb,
235 			      struct ext4_group_desc *bg)
236 {
237 	return le16_to_cpu(bg->bg_itable_unused_lo) |
238 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
239 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
240 }
241 
242 void ext4_block_bitmap_set(struct super_block *sb,
243 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
244 {
245 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
246 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
247 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
248 }
249 
250 void ext4_inode_bitmap_set(struct super_block *sb,
251 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
252 {
253 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
254 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
255 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
256 }
257 
258 void ext4_inode_table_set(struct super_block *sb,
259 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
260 {
261 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
262 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
263 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
264 }
265 
266 void ext4_free_group_clusters_set(struct super_block *sb,
267 				  struct ext4_group_desc *bg, __u32 count)
268 {
269 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
270 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
271 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
272 }
273 
274 void ext4_free_inodes_set(struct super_block *sb,
275 			  struct ext4_group_desc *bg, __u32 count)
276 {
277 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
278 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
279 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
280 }
281 
282 void ext4_used_dirs_set(struct super_block *sb,
283 			  struct ext4_group_desc *bg, __u32 count)
284 {
285 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
286 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
287 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
288 }
289 
290 void ext4_itable_unused_set(struct super_block *sb,
291 			  struct ext4_group_desc *bg, __u32 count)
292 {
293 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
294 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
295 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
296 }
297 
298 
299 /* Just increment the non-pointer handle value */
300 static handle_t *ext4_get_nojournal(void)
301 {
302 	handle_t *handle = current->journal_info;
303 	unsigned long ref_cnt = (unsigned long)handle;
304 
305 	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
306 
307 	ref_cnt++;
308 	handle = (handle_t *)ref_cnt;
309 
310 	current->journal_info = handle;
311 	return handle;
312 }
313 
314 
315 /* Decrement the non-pointer handle value */
316 static void ext4_put_nojournal(handle_t *handle)
317 {
318 	unsigned long ref_cnt = (unsigned long)handle;
319 
320 	BUG_ON(ref_cnt == 0);
321 
322 	ref_cnt--;
323 	handle = (handle_t *)ref_cnt;
324 
325 	current->journal_info = handle;
326 }
327 
328 /*
329  * Wrappers for jbd2_journal_start/end.
330  */
331 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
332 {
333 	journal_t *journal;
334 
335 	trace_ext4_journal_start(sb, nblocks, _RET_IP_);
336 	if (sb->s_flags & MS_RDONLY)
337 		return ERR_PTR(-EROFS);
338 
339 	WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
340 	journal = EXT4_SB(sb)->s_journal;
341 	if (!journal)
342 		return ext4_get_nojournal();
343 	/*
344 	 * Special case here: if the journal has aborted behind our
345 	 * backs (eg. EIO in the commit thread), then we still need to
346 	 * take the FS itself readonly cleanly.
347 	 */
348 	if (is_journal_aborted(journal)) {
349 		ext4_abort(sb, "Detected aborted journal");
350 		return ERR_PTR(-EROFS);
351 	}
352 	return jbd2_journal_start(journal, nblocks);
353 }
354 
355 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
356 {
357 	struct super_block *sb;
358 	int err;
359 	int rc;
360 
361 	if (!ext4_handle_valid(handle)) {
362 		ext4_put_nojournal(handle);
363 		return 0;
364 	}
365 	sb = handle->h_transaction->t_journal->j_private;
366 	err = handle->h_err;
367 	rc = jbd2_journal_stop(handle);
368 
369 	if (!err)
370 		err = rc;
371 	if (err)
372 		__ext4_std_error(sb, where, line, err);
373 	return err;
374 }
375 
376 void ext4_journal_abort_handle(const char *caller, unsigned int line,
377 			       const char *err_fn, struct buffer_head *bh,
378 			       handle_t *handle, int err)
379 {
380 	char nbuf[16];
381 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
382 
383 	BUG_ON(!ext4_handle_valid(handle));
384 
385 	if (bh)
386 		BUFFER_TRACE(bh, "abort");
387 
388 	if (!handle->h_err)
389 		handle->h_err = err;
390 
391 	if (is_handle_aborted(handle))
392 		return;
393 
394 	printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
395 	       caller, line, errstr, err_fn);
396 
397 	jbd2_journal_abort_handle(handle);
398 }
399 
400 static void __save_error_info(struct super_block *sb, const char *func,
401 			    unsigned int line)
402 {
403 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
404 
405 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
406 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
407 	es->s_last_error_time = cpu_to_le32(get_seconds());
408 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
409 	es->s_last_error_line = cpu_to_le32(line);
410 	if (!es->s_first_error_time) {
411 		es->s_first_error_time = es->s_last_error_time;
412 		strncpy(es->s_first_error_func, func,
413 			sizeof(es->s_first_error_func));
414 		es->s_first_error_line = cpu_to_le32(line);
415 		es->s_first_error_ino = es->s_last_error_ino;
416 		es->s_first_error_block = es->s_last_error_block;
417 	}
418 	/*
419 	 * Start the daily error reporting function if it hasn't been
420 	 * started already
421 	 */
422 	if (!es->s_error_count)
423 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
424 	le32_add_cpu(&es->s_error_count, 1);
425 }
426 
427 static void save_error_info(struct super_block *sb, const char *func,
428 			    unsigned int line)
429 {
430 	__save_error_info(sb, func, line);
431 	ext4_commit_super(sb, 1);
432 }
433 
434 /*
435  * The del_gendisk() function uninitializes the disk-specific data
436  * structures, including the bdi structure, without telling anyone
437  * else.  Once this happens, any attempt to call mark_buffer_dirty()
438  * (for example, by ext4_commit_super), will cause a kernel OOPS.
439  * This is a kludge to prevent these oops until we can put in a proper
440  * hook in del_gendisk() to inform the VFS and file system layers.
441  */
442 static int block_device_ejected(struct super_block *sb)
443 {
444 	struct inode *bd_inode = sb->s_bdev->bd_inode;
445 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
446 
447 	return bdi->dev == NULL;
448 }
449 
450 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
451 {
452 	struct super_block		*sb = journal->j_private;
453 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
454 	int				error = is_journal_aborted(journal);
455 	struct ext4_journal_cb_entry	*jce, *tmp;
456 
457 	spin_lock(&sbi->s_md_lock);
458 	list_for_each_entry_safe(jce, tmp, &txn->t_private_list, jce_list) {
459 		list_del_init(&jce->jce_list);
460 		spin_unlock(&sbi->s_md_lock);
461 		jce->jce_func(sb, jce, error);
462 		spin_lock(&sbi->s_md_lock);
463 	}
464 	spin_unlock(&sbi->s_md_lock);
465 }
466 
467 /* Deal with the reporting of failure conditions on a filesystem such as
468  * inconsistencies detected or read IO failures.
469  *
470  * On ext2, we can store the error state of the filesystem in the
471  * superblock.  That is not possible on ext4, because we may have other
472  * write ordering constraints on the superblock which prevent us from
473  * writing it out straight away; and given that the journal is about to
474  * be aborted, we can't rely on the current, or future, transactions to
475  * write out the superblock safely.
476  *
477  * We'll just use the jbd2_journal_abort() error code to record an error in
478  * the journal instead.  On recovery, the journal will complain about
479  * that error until we've noted it down and cleared it.
480  */
481 
482 static void ext4_handle_error(struct super_block *sb)
483 {
484 	if (sb->s_flags & MS_RDONLY)
485 		return;
486 
487 	if (!test_opt(sb, ERRORS_CONT)) {
488 		journal_t *journal = EXT4_SB(sb)->s_journal;
489 
490 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
491 		if (journal)
492 			jbd2_journal_abort(journal, -EIO);
493 	}
494 	if (test_opt(sb, ERRORS_RO)) {
495 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
496 		sb->s_flags |= MS_RDONLY;
497 	}
498 	if (test_opt(sb, ERRORS_PANIC))
499 		panic("EXT4-fs (device %s): panic forced after error\n",
500 			sb->s_id);
501 }
502 
503 void __ext4_error(struct super_block *sb, const char *function,
504 		  unsigned int line, const char *fmt, ...)
505 {
506 	struct va_format vaf;
507 	va_list args;
508 
509 	va_start(args, fmt);
510 	vaf.fmt = fmt;
511 	vaf.va = &args;
512 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
513 	       sb->s_id, function, line, current->comm, &vaf);
514 	va_end(args);
515 	save_error_info(sb, function, line);
516 
517 	ext4_handle_error(sb);
518 }
519 
520 void ext4_error_inode(struct inode *inode, const char *function,
521 		      unsigned int line, ext4_fsblk_t block,
522 		      const char *fmt, ...)
523 {
524 	va_list args;
525 	struct va_format vaf;
526 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
527 
528 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
529 	es->s_last_error_block = cpu_to_le64(block);
530 	save_error_info(inode->i_sb, function, line);
531 	va_start(args, fmt);
532 	vaf.fmt = fmt;
533 	vaf.va = &args;
534 	if (block)
535 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
536 		       "inode #%lu: block %llu: comm %s: %pV\n",
537 		       inode->i_sb->s_id, function, line, inode->i_ino,
538 		       block, current->comm, &vaf);
539 	else
540 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
541 		       "inode #%lu: comm %s: %pV\n",
542 		       inode->i_sb->s_id, function, line, inode->i_ino,
543 		       current->comm, &vaf);
544 	va_end(args);
545 
546 	ext4_handle_error(inode->i_sb);
547 }
548 
549 void ext4_error_file(struct file *file, const char *function,
550 		     unsigned int line, ext4_fsblk_t block,
551 		     const char *fmt, ...)
552 {
553 	va_list args;
554 	struct va_format vaf;
555 	struct ext4_super_block *es;
556 	struct inode *inode = file->f_dentry->d_inode;
557 	char pathname[80], *path;
558 
559 	es = EXT4_SB(inode->i_sb)->s_es;
560 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
561 	save_error_info(inode->i_sb, function, line);
562 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
563 	if (IS_ERR(path))
564 		path = "(unknown)";
565 	va_start(args, fmt);
566 	vaf.fmt = fmt;
567 	vaf.va = &args;
568 	if (block)
569 		printk(KERN_CRIT
570 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
571 		       "block %llu: comm %s: path %s: %pV\n",
572 		       inode->i_sb->s_id, function, line, inode->i_ino,
573 		       block, current->comm, path, &vaf);
574 	else
575 		printk(KERN_CRIT
576 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
577 		       "comm %s: path %s: %pV\n",
578 		       inode->i_sb->s_id, function, line, inode->i_ino,
579 		       current->comm, path, &vaf);
580 	va_end(args);
581 
582 	ext4_handle_error(inode->i_sb);
583 }
584 
585 static const char *ext4_decode_error(struct super_block *sb, int errno,
586 				     char nbuf[16])
587 {
588 	char *errstr = NULL;
589 
590 	switch (errno) {
591 	case -EIO:
592 		errstr = "IO failure";
593 		break;
594 	case -ENOMEM:
595 		errstr = "Out of memory";
596 		break;
597 	case -EROFS:
598 		if (!sb || (EXT4_SB(sb)->s_journal &&
599 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
600 			errstr = "Journal has aborted";
601 		else
602 			errstr = "Readonly filesystem";
603 		break;
604 	default:
605 		/* If the caller passed in an extra buffer for unknown
606 		 * errors, textualise them now.  Else we just return
607 		 * NULL. */
608 		if (nbuf) {
609 			/* Check for truncated error codes... */
610 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
611 				errstr = nbuf;
612 		}
613 		break;
614 	}
615 
616 	return errstr;
617 }
618 
619 /* __ext4_std_error decodes expected errors from journaling functions
620  * automatically and invokes the appropriate error response.  */
621 
622 void __ext4_std_error(struct super_block *sb, const char *function,
623 		      unsigned int line, int errno)
624 {
625 	char nbuf[16];
626 	const char *errstr;
627 
628 	/* Special case: if the error is EROFS, and we're not already
629 	 * inside a transaction, then there's really no point in logging
630 	 * an error. */
631 	if (errno == -EROFS && journal_current_handle() == NULL &&
632 	    (sb->s_flags & MS_RDONLY))
633 		return;
634 
635 	errstr = ext4_decode_error(sb, errno, nbuf);
636 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
637 	       sb->s_id, function, line, errstr);
638 	save_error_info(sb, function, line);
639 
640 	ext4_handle_error(sb);
641 }
642 
643 /*
644  * ext4_abort is a much stronger failure handler than ext4_error.  The
645  * abort function may be used to deal with unrecoverable failures such
646  * as journal IO errors or ENOMEM at a critical moment in log management.
647  *
648  * We unconditionally force the filesystem into an ABORT|READONLY state,
649  * unless the error response on the fs has been set to panic in which
650  * case we take the easy way out and panic immediately.
651  */
652 
653 void __ext4_abort(struct super_block *sb, const char *function,
654 		unsigned int line, const char *fmt, ...)
655 {
656 	va_list args;
657 
658 	save_error_info(sb, function, line);
659 	va_start(args, fmt);
660 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
661 	       function, line);
662 	vprintk(fmt, args);
663 	printk("\n");
664 	va_end(args);
665 
666 	if ((sb->s_flags & MS_RDONLY) == 0) {
667 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
668 		sb->s_flags |= MS_RDONLY;
669 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
670 		if (EXT4_SB(sb)->s_journal)
671 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
672 		save_error_info(sb, function, line);
673 	}
674 	if (test_opt(sb, ERRORS_PANIC))
675 		panic("EXT4-fs panic from previous error\n");
676 }
677 
678 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
679 {
680 	struct va_format vaf;
681 	va_list args;
682 
683 	va_start(args, fmt);
684 	vaf.fmt = fmt;
685 	vaf.va = &args;
686 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
687 	va_end(args);
688 }
689 
690 void __ext4_warning(struct super_block *sb, const char *function,
691 		    unsigned int line, const char *fmt, ...)
692 {
693 	struct va_format vaf;
694 	va_list args;
695 
696 	va_start(args, fmt);
697 	vaf.fmt = fmt;
698 	vaf.va = &args;
699 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
700 	       sb->s_id, function, line, &vaf);
701 	va_end(args);
702 }
703 
704 void __ext4_grp_locked_error(const char *function, unsigned int line,
705 			     struct super_block *sb, ext4_group_t grp,
706 			     unsigned long ino, ext4_fsblk_t block,
707 			     const char *fmt, ...)
708 __releases(bitlock)
709 __acquires(bitlock)
710 {
711 	struct va_format vaf;
712 	va_list args;
713 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
714 
715 	es->s_last_error_ino = cpu_to_le32(ino);
716 	es->s_last_error_block = cpu_to_le64(block);
717 	__save_error_info(sb, function, line);
718 
719 	va_start(args, fmt);
720 
721 	vaf.fmt = fmt;
722 	vaf.va = &args;
723 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
724 	       sb->s_id, function, line, grp);
725 	if (ino)
726 		printk(KERN_CONT "inode %lu: ", ino);
727 	if (block)
728 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
729 	printk(KERN_CONT "%pV\n", &vaf);
730 	va_end(args);
731 
732 	if (test_opt(sb, ERRORS_CONT)) {
733 		ext4_commit_super(sb, 0);
734 		return;
735 	}
736 
737 	ext4_unlock_group(sb, grp);
738 	ext4_handle_error(sb);
739 	/*
740 	 * We only get here in the ERRORS_RO case; relocking the group
741 	 * may be dangerous, but nothing bad will happen since the
742 	 * filesystem will have already been marked read/only and the
743 	 * journal has been aborted.  We return 1 as a hint to callers
744 	 * who might what to use the return value from
745 	 * ext4_grp_locked_error() to distinguish between the
746 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
747 	 * aggressively from the ext4 function in question, with a
748 	 * more appropriate error code.
749 	 */
750 	ext4_lock_group(sb, grp);
751 	return;
752 }
753 
754 void ext4_update_dynamic_rev(struct super_block *sb)
755 {
756 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
757 
758 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
759 		return;
760 
761 	ext4_warning(sb,
762 		     "updating to rev %d because of new feature flag, "
763 		     "running e2fsck is recommended",
764 		     EXT4_DYNAMIC_REV);
765 
766 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
767 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
768 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
769 	/* leave es->s_feature_*compat flags alone */
770 	/* es->s_uuid will be set by e2fsck if empty */
771 
772 	/*
773 	 * The rest of the superblock fields should be zero, and if not it
774 	 * means they are likely already in use, so leave them alone.  We
775 	 * can leave it up to e2fsck to clean up any inconsistencies there.
776 	 */
777 }
778 
779 /*
780  * Open the external journal device
781  */
782 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
783 {
784 	struct block_device *bdev;
785 	char b[BDEVNAME_SIZE];
786 
787 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
788 	if (IS_ERR(bdev))
789 		goto fail;
790 	return bdev;
791 
792 fail:
793 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
794 			__bdevname(dev, b), PTR_ERR(bdev));
795 	return NULL;
796 }
797 
798 /*
799  * Release the journal device
800  */
801 static int ext4_blkdev_put(struct block_device *bdev)
802 {
803 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
804 }
805 
806 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
807 {
808 	struct block_device *bdev;
809 	int ret = -ENODEV;
810 
811 	bdev = sbi->journal_bdev;
812 	if (bdev) {
813 		ret = ext4_blkdev_put(bdev);
814 		sbi->journal_bdev = NULL;
815 	}
816 	return ret;
817 }
818 
819 static inline struct inode *orphan_list_entry(struct list_head *l)
820 {
821 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
822 }
823 
824 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
825 {
826 	struct list_head *l;
827 
828 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
829 		 le32_to_cpu(sbi->s_es->s_last_orphan));
830 
831 	printk(KERN_ERR "sb_info orphan list:\n");
832 	list_for_each(l, &sbi->s_orphan) {
833 		struct inode *inode = orphan_list_entry(l);
834 		printk(KERN_ERR "  "
835 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
836 		       inode->i_sb->s_id, inode->i_ino, inode,
837 		       inode->i_mode, inode->i_nlink,
838 		       NEXT_ORPHAN(inode));
839 	}
840 }
841 
842 static void ext4_put_super(struct super_block *sb)
843 {
844 	struct ext4_sb_info *sbi = EXT4_SB(sb);
845 	struct ext4_super_block *es = sbi->s_es;
846 	int i, err;
847 
848 	ext4_unregister_li_request(sb);
849 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
850 
851 	flush_workqueue(sbi->dio_unwritten_wq);
852 	destroy_workqueue(sbi->dio_unwritten_wq);
853 
854 	if (sbi->s_journal) {
855 		err = jbd2_journal_destroy(sbi->s_journal);
856 		sbi->s_journal = NULL;
857 		if (err < 0)
858 			ext4_abort(sb, "Couldn't clean up the journal");
859 	}
860 
861 	del_timer(&sbi->s_err_report);
862 	ext4_release_system_zone(sb);
863 	ext4_mb_release(sb);
864 	ext4_ext_release(sb);
865 	ext4_xattr_put_super(sb);
866 
867 	if (!(sb->s_flags & MS_RDONLY)) {
868 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
869 		es->s_state = cpu_to_le16(sbi->s_mount_state);
870 	}
871 	if (!(sb->s_flags & MS_RDONLY))
872 		ext4_commit_super(sb, 1);
873 
874 	if (sbi->s_proc) {
875 		remove_proc_entry("options", sbi->s_proc);
876 		remove_proc_entry(sb->s_id, ext4_proc_root);
877 	}
878 	kobject_del(&sbi->s_kobj);
879 
880 	for (i = 0; i < sbi->s_gdb_count; i++)
881 		brelse(sbi->s_group_desc[i]);
882 	ext4_kvfree(sbi->s_group_desc);
883 	ext4_kvfree(sbi->s_flex_groups);
884 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
885 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
886 	percpu_counter_destroy(&sbi->s_dirs_counter);
887 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
888 	brelse(sbi->s_sbh);
889 #ifdef CONFIG_QUOTA
890 	for (i = 0; i < MAXQUOTAS; i++)
891 		kfree(sbi->s_qf_names[i]);
892 #endif
893 
894 	/* Debugging code just in case the in-memory inode orphan list
895 	 * isn't empty.  The on-disk one can be non-empty if we've
896 	 * detected an error and taken the fs readonly, but the
897 	 * in-memory list had better be clean by this point. */
898 	if (!list_empty(&sbi->s_orphan))
899 		dump_orphan_list(sb, sbi);
900 	J_ASSERT(list_empty(&sbi->s_orphan));
901 
902 	invalidate_bdev(sb->s_bdev);
903 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
904 		/*
905 		 * Invalidate the journal device's buffers.  We don't want them
906 		 * floating about in memory - the physical journal device may
907 		 * hotswapped, and it breaks the `ro-after' testing code.
908 		 */
909 		sync_blockdev(sbi->journal_bdev);
910 		invalidate_bdev(sbi->journal_bdev);
911 		ext4_blkdev_remove(sbi);
912 	}
913 	if (sbi->s_mmp_tsk)
914 		kthread_stop(sbi->s_mmp_tsk);
915 	sb->s_fs_info = NULL;
916 	/*
917 	 * Now that we are completely done shutting down the
918 	 * superblock, we need to actually destroy the kobject.
919 	 */
920 	kobject_put(&sbi->s_kobj);
921 	wait_for_completion(&sbi->s_kobj_unregister);
922 	if (sbi->s_chksum_driver)
923 		crypto_free_shash(sbi->s_chksum_driver);
924 	kfree(sbi->s_blockgroup_lock);
925 	kfree(sbi);
926 }
927 
928 static struct kmem_cache *ext4_inode_cachep;
929 
930 /*
931  * Called inside transaction, so use GFP_NOFS
932  */
933 static struct inode *ext4_alloc_inode(struct super_block *sb)
934 {
935 	struct ext4_inode_info *ei;
936 
937 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
938 	if (!ei)
939 		return NULL;
940 
941 	ei->vfs_inode.i_version = 1;
942 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
943 	INIT_LIST_HEAD(&ei->i_prealloc_list);
944 	spin_lock_init(&ei->i_prealloc_lock);
945 	ext4_es_init_tree(&ei->i_es_tree);
946 	rwlock_init(&ei->i_es_lock);
947 	ei->i_reserved_data_blocks = 0;
948 	ei->i_reserved_meta_blocks = 0;
949 	ei->i_allocated_meta_blocks = 0;
950 	ei->i_da_metadata_calc_len = 0;
951 	ei->i_da_metadata_calc_last_lblock = 0;
952 	spin_lock_init(&(ei->i_block_reservation_lock));
953 #ifdef CONFIG_QUOTA
954 	ei->i_reserved_quota = 0;
955 #endif
956 	ei->jinode = NULL;
957 	INIT_LIST_HEAD(&ei->i_completed_io_list);
958 	spin_lock_init(&ei->i_completed_io_lock);
959 	ei->i_sync_tid = 0;
960 	ei->i_datasync_tid = 0;
961 	atomic_set(&ei->i_ioend_count, 0);
962 	atomic_set(&ei->i_unwritten, 0);
963 
964 	return &ei->vfs_inode;
965 }
966 
967 static int ext4_drop_inode(struct inode *inode)
968 {
969 	int drop = generic_drop_inode(inode);
970 
971 	trace_ext4_drop_inode(inode, drop);
972 	return drop;
973 }
974 
975 static void ext4_i_callback(struct rcu_head *head)
976 {
977 	struct inode *inode = container_of(head, struct inode, i_rcu);
978 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
979 }
980 
981 static void ext4_destroy_inode(struct inode *inode)
982 {
983 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
984 		ext4_msg(inode->i_sb, KERN_ERR,
985 			 "Inode %lu (%p): orphan list check failed!",
986 			 inode->i_ino, EXT4_I(inode));
987 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
988 				EXT4_I(inode), sizeof(struct ext4_inode_info),
989 				true);
990 		dump_stack();
991 	}
992 	call_rcu(&inode->i_rcu, ext4_i_callback);
993 }
994 
995 static void init_once(void *foo)
996 {
997 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
998 
999 	INIT_LIST_HEAD(&ei->i_orphan);
1000 	init_rwsem(&ei->xattr_sem);
1001 	init_rwsem(&ei->i_data_sem);
1002 	inode_init_once(&ei->vfs_inode);
1003 }
1004 
1005 static int init_inodecache(void)
1006 {
1007 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1008 					     sizeof(struct ext4_inode_info),
1009 					     0, (SLAB_RECLAIM_ACCOUNT|
1010 						SLAB_MEM_SPREAD),
1011 					     init_once);
1012 	if (ext4_inode_cachep == NULL)
1013 		return -ENOMEM;
1014 	return 0;
1015 }
1016 
1017 static void destroy_inodecache(void)
1018 {
1019 	/*
1020 	 * Make sure all delayed rcu free inodes are flushed before we
1021 	 * destroy cache.
1022 	 */
1023 	rcu_barrier();
1024 	kmem_cache_destroy(ext4_inode_cachep);
1025 }
1026 
1027 void ext4_clear_inode(struct inode *inode)
1028 {
1029 	invalidate_inode_buffers(inode);
1030 	clear_inode(inode);
1031 	dquot_drop(inode);
1032 	ext4_discard_preallocations(inode);
1033 	ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
1034 	if (EXT4_I(inode)->jinode) {
1035 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1036 					       EXT4_I(inode)->jinode);
1037 		jbd2_free_inode(EXT4_I(inode)->jinode);
1038 		EXT4_I(inode)->jinode = NULL;
1039 	}
1040 }
1041 
1042 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1043 					u64 ino, u32 generation)
1044 {
1045 	struct inode *inode;
1046 
1047 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1048 		return ERR_PTR(-ESTALE);
1049 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1050 		return ERR_PTR(-ESTALE);
1051 
1052 	/* iget isn't really right if the inode is currently unallocated!!
1053 	 *
1054 	 * ext4_read_inode will return a bad_inode if the inode had been
1055 	 * deleted, so we should be safe.
1056 	 *
1057 	 * Currently we don't know the generation for parent directory, so
1058 	 * a generation of 0 means "accept any"
1059 	 */
1060 	inode = ext4_iget(sb, ino);
1061 	if (IS_ERR(inode))
1062 		return ERR_CAST(inode);
1063 	if (generation && inode->i_generation != generation) {
1064 		iput(inode);
1065 		return ERR_PTR(-ESTALE);
1066 	}
1067 
1068 	return inode;
1069 }
1070 
1071 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1072 					int fh_len, int fh_type)
1073 {
1074 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1075 				    ext4_nfs_get_inode);
1076 }
1077 
1078 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1079 					int fh_len, int fh_type)
1080 {
1081 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1082 				    ext4_nfs_get_inode);
1083 }
1084 
1085 /*
1086  * Try to release metadata pages (indirect blocks, directories) which are
1087  * mapped via the block device.  Since these pages could have journal heads
1088  * which would prevent try_to_free_buffers() from freeing them, we must use
1089  * jbd2 layer's try_to_free_buffers() function to release them.
1090  */
1091 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1092 				 gfp_t wait)
1093 {
1094 	journal_t *journal = EXT4_SB(sb)->s_journal;
1095 
1096 	WARN_ON(PageChecked(page));
1097 	if (!page_has_buffers(page))
1098 		return 0;
1099 	if (journal)
1100 		return jbd2_journal_try_to_free_buffers(journal, page,
1101 							wait & ~__GFP_WAIT);
1102 	return try_to_free_buffers(page);
1103 }
1104 
1105 #ifdef CONFIG_QUOTA
1106 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1107 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1108 
1109 static int ext4_write_dquot(struct dquot *dquot);
1110 static int ext4_acquire_dquot(struct dquot *dquot);
1111 static int ext4_release_dquot(struct dquot *dquot);
1112 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1113 static int ext4_write_info(struct super_block *sb, int type);
1114 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1115 			 struct path *path);
1116 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1117 				 int format_id);
1118 static int ext4_quota_off(struct super_block *sb, int type);
1119 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1120 static int ext4_quota_on_mount(struct super_block *sb, int type);
1121 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1122 			       size_t len, loff_t off);
1123 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1124 				const char *data, size_t len, loff_t off);
1125 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1126 			     unsigned int flags);
1127 static int ext4_enable_quotas(struct super_block *sb);
1128 
1129 static const struct dquot_operations ext4_quota_operations = {
1130 	.get_reserved_space = ext4_get_reserved_space,
1131 	.write_dquot	= ext4_write_dquot,
1132 	.acquire_dquot	= ext4_acquire_dquot,
1133 	.release_dquot	= ext4_release_dquot,
1134 	.mark_dirty	= ext4_mark_dquot_dirty,
1135 	.write_info	= ext4_write_info,
1136 	.alloc_dquot	= dquot_alloc,
1137 	.destroy_dquot	= dquot_destroy,
1138 };
1139 
1140 static const struct quotactl_ops ext4_qctl_operations = {
1141 	.quota_on	= ext4_quota_on,
1142 	.quota_off	= ext4_quota_off,
1143 	.quota_sync	= dquot_quota_sync,
1144 	.get_info	= dquot_get_dqinfo,
1145 	.set_info	= dquot_set_dqinfo,
1146 	.get_dqblk	= dquot_get_dqblk,
1147 	.set_dqblk	= dquot_set_dqblk
1148 };
1149 
1150 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1151 	.quota_on_meta	= ext4_quota_on_sysfile,
1152 	.quota_off	= ext4_quota_off_sysfile,
1153 	.quota_sync	= dquot_quota_sync,
1154 	.get_info	= dquot_get_dqinfo,
1155 	.set_info	= dquot_set_dqinfo,
1156 	.get_dqblk	= dquot_get_dqblk,
1157 	.set_dqblk	= dquot_set_dqblk
1158 };
1159 #endif
1160 
1161 static const struct super_operations ext4_sops = {
1162 	.alloc_inode	= ext4_alloc_inode,
1163 	.destroy_inode	= ext4_destroy_inode,
1164 	.write_inode	= ext4_write_inode,
1165 	.dirty_inode	= ext4_dirty_inode,
1166 	.drop_inode	= ext4_drop_inode,
1167 	.evict_inode	= ext4_evict_inode,
1168 	.put_super	= ext4_put_super,
1169 	.sync_fs	= ext4_sync_fs,
1170 	.freeze_fs	= ext4_freeze,
1171 	.unfreeze_fs	= ext4_unfreeze,
1172 	.statfs		= ext4_statfs,
1173 	.remount_fs	= ext4_remount,
1174 	.show_options	= ext4_show_options,
1175 #ifdef CONFIG_QUOTA
1176 	.quota_read	= ext4_quota_read,
1177 	.quota_write	= ext4_quota_write,
1178 #endif
1179 	.bdev_try_to_free_page = bdev_try_to_free_page,
1180 };
1181 
1182 static const struct super_operations ext4_nojournal_sops = {
1183 	.alloc_inode	= ext4_alloc_inode,
1184 	.destroy_inode	= ext4_destroy_inode,
1185 	.write_inode	= ext4_write_inode,
1186 	.dirty_inode	= ext4_dirty_inode,
1187 	.drop_inode	= ext4_drop_inode,
1188 	.evict_inode	= ext4_evict_inode,
1189 	.put_super	= ext4_put_super,
1190 	.statfs		= ext4_statfs,
1191 	.remount_fs	= ext4_remount,
1192 	.show_options	= ext4_show_options,
1193 #ifdef CONFIG_QUOTA
1194 	.quota_read	= ext4_quota_read,
1195 	.quota_write	= ext4_quota_write,
1196 #endif
1197 	.bdev_try_to_free_page = bdev_try_to_free_page,
1198 };
1199 
1200 static const struct export_operations ext4_export_ops = {
1201 	.fh_to_dentry = ext4_fh_to_dentry,
1202 	.fh_to_parent = ext4_fh_to_parent,
1203 	.get_parent = ext4_get_parent,
1204 };
1205 
1206 enum {
1207 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1208 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1209 	Opt_nouid32, Opt_debug, Opt_removed,
1210 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1211 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1212 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1213 	Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1214 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1215 	Opt_data_err_abort, Opt_data_err_ignore,
1216 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1217 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1218 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1219 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1220 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1221 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1222 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1223 	Opt_dioread_nolock, Opt_dioread_lock,
1224 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1225 	Opt_max_dir_size_kb,
1226 };
1227 
1228 static const match_table_t tokens = {
1229 	{Opt_bsd_df, "bsddf"},
1230 	{Opt_minix_df, "minixdf"},
1231 	{Opt_grpid, "grpid"},
1232 	{Opt_grpid, "bsdgroups"},
1233 	{Opt_nogrpid, "nogrpid"},
1234 	{Opt_nogrpid, "sysvgroups"},
1235 	{Opt_resgid, "resgid=%u"},
1236 	{Opt_resuid, "resuid=%u"},
1237 	{Opt_sb, "sb=%u"},
1238 	{Opt_err_cont, "errors=continue"},
1239 	{Opt_err_panic, "errors=panic"},
1240 	{Opt_err_ro, "errors=remount-ro"},
1241 	{Opt_nouid32, "nouid32"},
1242 	{Opt_debug, "debug"},
1243 	{Opt_removed, "oldalloc"},
1244 	{Opt_removed, "orlov"},
1245 	{Opt_user_xattr, "user_xattr"},
1246 	{Opt_nouser_xattr, "nouser_xattr"},
1247 	{Opt_acl, "acl"},
1248 	{Opt_noacl, "noacl"},
1249 	{Opt_noload, "norecovery"},
1250 	{Opt_noload, "noload"},
1251 	{Opt_removed, "nobh"},
1252 	{Opt_removed, "bh"},
1253 	{Opt_commit, "commit=%u"},
1254 	{Opt_min_batch_time, "min_batch_time=%u"},
1255 	{Opt_max_batch_time, "max_batch_time=%u"},
1256 	{Opt_journal_dev, "journal_dev=%u"},
1257 	{Opt_journal_checksum, "journal_checksum"},
1258 	{Opt_journal_async_commit, "journal_async_commit"},
1259 	{Opt_abort, "abort"},
1260 	{Opt_data_journal, "data=journal"},
1261 	{Opt_data_ordered, "data=ordered"},
1262 	{Opt_data_writeback, "data=writeback"},
1263 	{Opt_data_err_abort, "data_err=abort"},
1264 	{Opt_data_err_ignore, "data_err=ignore"},
1265 	{Opt_offusrjquota, "usrjquota="},
1266 	{Opt_usrjquota, "usrjquota=%s"},
1267 	{Opt_offgrpjquota, "grpjquota="},
1268 	{Opt_grpjquota, "grpjquota=%s"},
1269 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1270 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1271 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1272 	{Opt_grpquota, "grpquota"},
1273 	{Opt_noquota, "noquota"},
1274 	{Opt_quota, "quota"},
1275 	{Opt_usrquota, "usrquota"},
1276 	{Opt_barrier, "barrier=%u"},
1277 	{Opt_barrier, "barrier"},
1278 	{Opt_nobarrier, "nobarrier"},
1279 	{Opt_i_version, "i_version"},
1280 	{Opt_stripe, "stripe=%u"},
1281 	{Opt_delalloc, "delalloc"},
1282 	{Opt_nodelalloc, "nodelalloc"},
1283 	{Opt_mblk_io_submit, "mblk_io_submit"},
1284 	{Opt_nomblk_io_submit, "nomblk_io_submit"},
1285 	{Opt_block_validity, "block_validity"},
1286 	{Opt_noblock_validity, "noblock_validity"},
1287 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1288 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1289 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1290 	{Opt_auto_da_alloc, "auto_da_alloc"},
1291 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1292 	{Opt_dioread_nolock, "dioread_nolock"},
1293 	{Opt_dioread_lock, "dioread_lock"},
1294 	{Opt_discard, "discard"},
1295 	{Opt_nodiscard, "nodiscard"},
1296 	{Opt_init_itable, "init_itable=%u"},
1297 	{Opt_init_itable, "init_itable"},
1298 	{Opt_noinit_itable, "noinit_itable"},
1299 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1300 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1301 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1302 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1303 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1304 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1305 	{Opt_err, NULL},
1306 };
1307 
1308 static ext4_fsblk_t get_sb_block(void **data)
1309 {
1310 	ext4_fsblk_t	sb_block;
1311 	char		*options = (char *) *data;
1312 
1313 	if (!options || strncmp(options, "sb=", 3) != 0)
1314 		return 1;	/* Default location */
1315 
1316 	options += 3;
1317 	/* TODO: use simple_strtoll with >32bit ext4 */
1318 	sb_block = simple_strtoul(options, &options, 0);
1319 	if (*options && *options != ',') {
1320 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1321 		       (char *) *data);
1322 		return 1;
1323 	}
1324 	if (*options == ',')
1325 		options++;
1326 	*data = (void *) options;
1327 
1328 	return sb_block;
1329 }
1330 
1331 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1332 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1333 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1334 
1335 #ifdef CONFIG_QUOTA
1336 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1337 {
1338 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1339 	char *qname;
1340 
1341 	if (sb_any_quota_loaded(sb) &&
1342 		!sbi->s_qf_names[qtype]) {
1343 		ext4_msg(sb, KERN_ERR,
1344 			"Cannot change journaled "
1345 			"quota options when quota turned on");
1346 		return -1;
1347 	}
1348 	qname = match_strdup(args);
1349 	if (!qname) {
1350 		ext4_msg(sb, KERN_ERR,
1351 			"Not enough memory for storing quotafile name");
1352 		return -1;
1353 	}
1354 	if (sbi->s_qf_names[qtype] &&
1355 		strcmp(sbi->s_qf_names[qtype], qname)) {
1356 		ext4_msg(sb, KERN_ERR,
1357 			"%s quota file already specified", QTYPE2NAME(qtype));
1358 		kfree(qname);
1359 		return -1;
1360 	}
1361 	sbi->s_qf_names[qtype] = qname;
1362 	if (strchr(sbi->s_qf_names[qtype], '/')) {
1363 		ext4_msg(sb, KERN_ERR,
1364 			"quotafile must be on filesystem root");
1365 		kfree(sbi->s_qf_names[qtype]);
1366 		sbi->s_qf_names[qtype] = NULL;
1367 		return -1;
1368 	}
1369 	set_opt(sb, QUOTA);
1370 	return 1;
1371 }
1372 
1373 static int clear_qf_name(struct super_block *sb, int qtype)
1374 {
1375 
1376 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1377 
1378 	if (sb_any_quota_loaded(sb) &&
1379 		sbi->s_qf_names[qtype]) {
1380 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1381 			" when quota turned on");
1382 		return -1;
1383 	}
1384 	/*
1385 	 * The space will be released later when all options are confirmed
1386 	 * to be correct
1387 	 */
1388 	sbi->s_qf_names[qtype] = NULL;
1389 	return 1;
1390 }
1391 #endif
1392 
1393 #define MOPT_SET	0x0001
1394 #define MOPT_CLEAR	0x0002
1395 #define MOPT_NOSUPPORT	0x0004
1396 #define MOPT_EXPLICIT	0x0008
1397 #define MOPT_CLEAR_ERR	0x0010
1398 #define MOPT_GTE0	0x0020
1399 #ifdef CONFIG_QUOTA
1400 #define MOPT_Q		0
1401 #define MOPT_QFMT	0x0040
1402 #else
1403 #define MOPT_Q		MOPT_NOSUPPORT
1404 #define MOPT_QFMT	MOPT_NOSUPPORT
1405 #endif
1406 #define MOPT_DATAJ	0x0080
1407 
1408 static const struct mount_opts {
1409 	int	token;
1410 	int	mount_opt;
1411 	int	flags;
1412 } ext4_mount_opts[] = {
1413 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1414 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1415 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1416 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1417 	{Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
1418 	{Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
1419 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1420 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1421 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
1422 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_CLEAR},
1423 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1424 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1425 	{Opt_delalloc, EXT4_MOUNT_DELALLOC, MOPT_SET | MOPT_EXPLICIT},
1426 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC, MOPT_CLEAR | MOPT_EXPLICIT},
1427 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM, MOPT_SET},
1428 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1429 				    EXT4_MOUNT_JOURNAL_CHECKSUM), MOPT_SET},
1430 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_SET},
1431 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1432 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1433 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1434 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_SET},
1435 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_CLEAR},
1436 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1437 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1438 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1439 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1440 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1441 	{Opt_commit, 0, MOPT_GTE0},
1442 	{Opt_max_batch_time, 0, MOPT_GTE0},
1443 	{Opt_min_batch_time, 0, MOPT_GTE0},
1444 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1445 	{Opt_init_itable, 0, MOPT_GTE0},
1446 	{Opt_stripe, 0, MOPT_GTE0},
1447 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
1448 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
1449 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
1450 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1451 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1452 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1453 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1454 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1455 #else
1456 	{Opt_acl, 0, MOPT_NOSUPPORT},
1457 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1458 #endif
1459 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1460 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1461 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1462 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1463 							MOPT_SET | MOPT_Q},
1464 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1465 							MOPT_SET | MOPT_Q},
1466 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1467 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1468 	{Opt_usrjquota, 0, MOPT_Q},
1469 	{Opt_grpjquota, 0, MOPT_Q},
1470 	{Opt_offusrjquota, 0, MOPT_Q},
1471 	{Opt_offgrpjquota, 0, MOPT_Q},
1472 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1473 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1474 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1475 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1476 	{Opt_err, 0, 0}
1477 };
1478 
1479 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1480 			    substring_t *args, unsigned long *journal_devnum,
1481 			    unsigned int *journal_ioprio, int is_remount)
1482 {
1483 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1484 	const struct mount_opts *m;
1485 	kuid_t uid;
1486 	kgid_t gid;
1487 	int arg = 0;
1488 
1489 #ifdef CONFIG_QUOTA
1490 	if (token == Opt_usrjquota)
1491 		return set_qf_name(sb, USRQUOTA, &args[0]);
1492 	else if (token == Opt_grpjquota)
1493 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1494 	else if (token == Opt_offusrjquota)
1495 		return clear_qf_name(sb, USRQUOTA);
1496 	else if (token == Opt_offgrpjquota)
1497 		return clear_qf_name(sb, GRPQUOTA);
1498 #endif
1499 	if (args->from && match_int(args, &arg))
1500 		return -1;
1501 	switch (token) {
1502 	case Opt_noacl:
1503 	case Opt_nouser_xattr:
1504 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1505 		break;
1506 	case Opt_sb:
1507 		return 1;	/* handled by get_sb_block() */
1508 	case Opt_removed:
1509 		ext4_msg(sb, KERN_WARNING,
1510 			 "Ignoring removed %s option", opt);
1511 		return 1;
1512 	case Opt_resuid:
1513 		uid = make_kuid(current_user_ns(), arg);
1514 		if (!uid_valid(uid)) {
1515 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1516 			return -1;
1517 		}
1518 		sbi->s_resuid = uid;
1519 		return 1;
1520 	case Opt_resgid:
1521 		gid = make_kgid(current_user_ns(), arg);
1522 		if (!gid_valid(gid)) {
1523 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1524 			return -1;
1525 		}
1526 		sbi->s_resgid = gid;
1527 		return 1;
1528 	case Opt_abort:
1529 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1530 		return 1;
1531 	case Opt_i_version:
1532 		sb->s_flags |= MS_I_VERSION;
1533 		return 1;
1534 	case Opt_journal_dev:
1535 		if (is_remount) {
1536 			ext4_msg(sb, KERN_ERR,
1537 				 "Cannot specify journal on remount");
1538 			return -1;
1539 		}
1540 		*journal_devnum = arg;
1541 		return 1;
1542 	case Opt_journal_ioprio:
1543 		if (arg < 0 || arg > 7)
1544 			return -1;
1545 		*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1546 		return 1;
1547 	}
1548 
1549 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1550 		if (token != m->token)
1551 			continue;
1552 		if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1553 			return -1;
1554 		if (m->flags & MOPT_EXPLICIT)
1555 			set_opt2(sb, EXPLICIT_DELALLOC);
1556 		if (m->flags & MOPT_CLEAR_ERR)
1557 			clear_opt(sb, ERRORS_MASK);
1558 		if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1559 			ext4_msg(sb, KERN_ERR, "Cannot change quota "
1560 				 "options when quota turned on");
1561 			return -1;
1562 		}
1563 
1564 		if (m->flags & MOPT_NOSUPPORT) {
1565 			ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1566 		} else if (token == Opt_commit) {
1567 			if (arg == 0)
1568 				arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1569 			sbi->s_commit_interval = HZ * arg;
1570 		} else if (token == Opt_max_batch_time) {
1571 			if (arg == 0)
1572 				arg = EXT4_DEF_MAX_BATCH_TIME;
1573 			sbi->s_max_batch_time = arg;
1574 		} else if (token == Opt_min_batch_time) {
1575 			sbi->s_min_batch_time = arg;
1576 		} else if (token == Opt_inode_readahead_blks) {
1577 			if (arg > (1 << 30))
1578 				return -1;
1579 			if (arg && !is_power_of_2(arg)) {
1580 				ext4_msg(sb, KERN_ERR,
1581 					 "EXT4-fs: inode_readahead_blks"
1582 					 " must be a power of 2");
1583 				return -1;
1584 			}
1585 			sbi->s_inode_readahead_blks = arg;
1586 		} else if (token == Opt_init_itable) {
1587 			set_opt(sb, INIT_INODE_TABLE);
1588 			if (!args->from)
1589 				arg = EXT4_DEF_LI_WAIT_MULT;
1590 			sbi->s_li_wait_mult = arg;
1591 		} else if (token == Opt_max_dir_size_kb) {
1592 			sbi->s_max_dir_size_kb = arg;
1593 		} else if (token == Opt_stripe) {
1594 			sbi->s_stripe = arg;
1595 		} else if (m->flags & MOPT_DATAJ) {
1596 			if (is_remount) {
1597 				if (!sbi->s_journal)
1598 					ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1599 				else if (test_opt(sb, DATA_FLAGS) !=
1600 					 m->mount_opt) {
1601 					ext4_msg(sb, KERN_ERR,
1602 					 "Cannot change data mode on remount");
1603 					return -1;
1604 				}
1605 			} else {
1606 				clear_opt(sb, DATA_FLAGS);
1607 				sbi->s_mount_opt |= m->mount_opt;
1608 			}
1609 #ifdef CONFIG_QUOTA
1610 		} else if (m->flags & MOPT_QFMT) {
1611 			if (sb_any_quota_loaded(sb) &&
1612 			    sbi->s_jquota_fmt != m->mount_opt) {
1613 				ext4_msg(sb, KERN_ERR, "Cannot "
1614 					 "change journaled quota options "
1615 					 "when quota turned on");
1616 				return -1;
1617 			}
1618 			sbi->s_jquota_fmt = m->mount_opt;
1619 #endif
1620 		} else {
1621 			if (!args->from)
1622 				arg = 1;
1623 			if (m->flags & MOPT_CLEAR)
1624 				arg = !arg;
1625 			else if (unlikely(!(m->flags & MOPT_SET))) {
1626 				ext4_msg(sb, KERN_WARNING,
1627 					 "buggy handling of option %s", opt);
1628 				WARN_ON(1);
1629 				return -1;
1630 			}
1631 			if (arg != 0)
1632 				sbi->s_mount_opt |= m->mount_opt;
1633 			else
1634 				sbi->s_mount_opt &= ~m->mount_opt;
1635 		}
1636 		return 1;
1637 	}
1638 	ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1639 		 "or missing value", opt);
1640 	return -1;
1641 }
1642 
1643 static int parse_options(char *options, struct super_block *sb,
1644 			 unsigned long *journal_devnum,
1645 			 unsigned int *journal_ioprio,
1646 			 int is_remount)
1647 {
1648 #ifdef CONFIG_QUOTA
1649 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1650 #endif
1651 	char *p;
1652 	substring_t args[MAX_OPT_ARGS];
1653 	int token;
1654 
1655 	if (!options)
1656 		return 1;
1657 
1658 	while ((p = strsep(&options, ",")) != NULL) {
1659 		if (!*p)
1660 			continue;
1661 		/*
1662 		 * Initialize args struct so we know whether arg was
1663 		 * found; some options take optional arguments.
1664 		 */
1665 		args[0].to = args[0].from = NULL;
1666 		token = match_token(p, tokens, args);
1667 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1668 				     journal_ioprio, is_remount) < 0)
1669 			return 0;
1670 	}
1671 #ifdef CONFIG_QUOTA
1672 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1673 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1674 			clear_opt(sb, USRQUOTA);
1675 
1676 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1677 			clear_opt(sb, GRPQUOTA);
1678 
1679 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1680 			ext4_msg(sb, KERN_ERR, "old and new quota "
1681 					"format mixing");
1682 			return 0;
1683 		}
1684 
1685 		if (!sbi->s_jquota_fmt) {
1686 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1687 					"not specified");
1688 			return 0;
1689 		}
1690 	} else {
1691 		if (sbi->s_jquota_fmt) {
1692 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1693 					"specified with no journaling "
1694 					"enabled");
1695 			return 0;
1696 		}
1697 	}
1698 #endif
1699 	return 1;
1700 }
1701 
1702 static inline void ext4_show_quota_options(struct seq_file *seq,
1703 					   struct super_block *sb)
1704 {
1705 #if defined(CONFIG_QUOTA)
1706 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1707 
1708 	if (sbi->s_jquota_fmt) {
1709 		char *fmtname = "";
1710 
1711 		switch (sbi->s_jquota_fmt) {
1712 		case QFMT_VFS_OLD:
1713 			fmtname = "vfsold";
1714 			break;
1715 		case QFMT_VFS_V0:
1716 			fmtname = "vfsv0";
1717 			break;
1718 		case QFMT_VFS_V1:
1719 			fmtname = "vfsv1";
1720 			break;
1721 		}
1722 		seq_printf(seq, ",jqfmt=%s", fmtname);
1723 	}
1724 
1725 	if (sbi->s_qf_names[USRQUOTA])
1726 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1727 
1728 	if (sbi->s_qf_names[GRPQUOTA])
1729 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1730 
1731 	if (test_opt(sb, USRQUOTA))
1732 		seq_puts(seq, ",usrquota");
1733 
1734 	if (test_opt(sb, GRPQUOTA))
1735 		seq_puts(seq, ",grpquota");
1736 #endif
1737 }
1738 
1739 static const char *token2str(int token)
1740 {
1741 	const struct match_token *t;
1742 
1743 	for (t = tokens; t->token != Opt_err; t++)
1744 		if (t->token == token && !strchr(t->pattern, '='))
1745 			break;
1746 	return t->pattern;
1747 }
1748 
1749 /*
1750  * Show an option if
1751  *  - it's set to a non-default value OR
1752  *  - if the per-sb default is different from the global default
1753  */
1754 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1755 			      int nodefs)
1756 {
1757 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1758 	struct ext4_super_block *es = sbi->s_es;
1759 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1760 	const struct mount_opts *m;
1761 	char sep = nodefs ? '\n' : ',';
1762 
1763 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1764 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1765 
1766 	if (sbi->s_sb_block != 1)
1767 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1768 
1769 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1770 		int want_set = m->flags & MOPT_SET;
1771 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1772 		    (m->flags & MOPT_CLEAR_ERR))
1773 			continue;
1774 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1775 			continue; /* skip if same as the default */
1776 		if ((want_set &&
1777 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1778 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1779 			continue; /* select Opt_noFoo vs Opt_Foo */
1780 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1781 	}
1782 
1783 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1784 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1785 		SEQ_OPTS_PRINT("resuid=%u",
1786 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1787 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1788 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1789 		SEQ_OPTS_PRINT("resgid=%u",
1790 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1791 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1792 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1793 		SEQ_OPTS_PUTS("errors=remount-ro");
1794 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1795 		SEQ_OPTS_PUTS("errors=continue");
1796 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1797 		SEQ_OPTS_PUTS("errors=panic");
1798 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1799 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1800 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1801 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1802 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1803 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1804 	if (sb->s_flags & MS_I_VERSION)
1805 		SEQ_OPTS_PUTS("i_version");
1806 	if (nodefs || sbi->s_stripe)
1807 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1808 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1809 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1810 			SEQ_OPTS_PUTS("data=journal");
1811 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1812 			SEQ_OPTS_PUTS("data=ordered");
1813 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1814 			SEQ_OPTS_PUTS("data=writeback");
1815 	}
1816 	if (nodefs ||
1817 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1818 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1819 			       sbi->s_inode_readahead_blks);
1820 
1821 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1822 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1823 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1824 	if (nodefs || sbi->s_max_dir_size_kb)
1825 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
1826 
1827 	ext4_show_quota_options(seq, sb);
1828 	return 0;
1829 }
1830 
1831 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1832 {
1833 	return _ext4_show_options(seq, root->d_sb, 0);
1834 }
1835 
1836 static int options_seq_show(struct seq_file *seq, void *offset)
1837 {
1838 	struct super_block *sb = seq->private;
1839 	int rc;
1840 
1841 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1842 	rc = _ext4_show_options(seq, sb, 1);
1843 	seq_puts(seq, "\n");
1844 	return rc;
1845 }
1846 
1847 static int options_open_fs(struct inode *inode, struct file *file)
1848 {
1849 	return single_open(file, options_seq_show, PDE(inode)->data);
1850 }
1851 
1852 static const struct file_operations ext4_seq_options_fops = {
1853 	.owner = THIS_MODULE,
1854 	.open = options_open_fs,
1855 	.read = seq_read,
1856 	.llseek = seq_lseek,
1857 	.release = single_release,
1858 };
1859 
1860 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1861 			    int read_only)
1862 {
1863 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1864 	int res = 0;
1865 
1866 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1867 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1868 			 "forcing read-only mode");
1869 		res = MS_RDONLY;
1870 	}
1871 	if (read_only)
1872 		goto done;
1873 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1874 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1875 			 "running e2fsck is recommended");
1876 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1877 		ext4_msg(sb, KERN_WARNING,
1878 			 "warning: mounting fs with errors, "
1879 			 "running e2fsck is recommended");
1880 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1881 		 le16_to_cpu(es->s_mnt_count) >=
1882 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1883 		ext4_msg(sb, KERN_WARNING,
1884 			 "warning: maximal mount count reached, "
1885 			 "running e2fsck is recommended");
1886 	else if (le32_to_cpu(es->s_checkinterval) &&
1887 		(le32_to_cpu(es->s_lastcheck) +
1888 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1889 		ext4_msg(sb, KERN_WARNING,
1890 			 "warning: checktime reached, "
1891 			 "running e2fsck is recommended");
1892 	if (!sbi->s_journal)
1893 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1894 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1895 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1896 	le16_add_cpu(&es->s_mnt_count, 1);
1897 	es->s_mtime = cpu_to_le32(get_seconds());
1898 	ext4_update_dynamic_rev(sb);
1899 	if (sbi->s_journal)
1900 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1901 
1902 	ext4_commit_super(sb, 1);
1903 done:
1904 	if (test_opt(sb, DEBUG))
1905 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1906 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1907 			sb->s_blocksize,
1908 			sbi->s_groups_count,
1909 			EXT4_BLOCKS_PER_GROUP(sb),
1910 			EXT4_INODES_PER_GROUP(sb),
1911 			sbi->s_mount_opt, sbi->s_mount_opt2);
1912 
1913 	cleancache_init_fs(sb);
1914 	return res;
1915 }
1916 
1917 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1918 {
1919 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1920 	struct flex_groups *new_groups;
1921 	int size;
1922 
1923 	if (!sbi->s_log_groups_per_flex)
1924 		return 0;
1925 
1926 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1927 	if (size <= sbi->s_flex_groups_allocated)
1928 		return 0;
1929 
1930 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1931 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1932 	if (!new_groups) {
1933 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1934 			 size / (int) sizeof(struct flex_groups));
1935 		return -ENOMEM;
1936 	}
1937 
1938 	if (sbi->s_flex_groups) {
1939 		memcpy(new_groups, sbi->s_flex_groups,
1940 		       (sbi->s_flex_groups_allocated *
1941 			sizeof(struct flex_groups)));
1942 		ext4_kvfree(sbi->s_flex_groups);
1943 	}
1944 	sbi->s_flex_groups = new_groups;
1945 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1946 	return 0;
1947 }
1948 
1949 static int ext4_fill_flex_info(struct super_block *sb)
1950 {
1951 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1952 	struct ext4_group_desc *gdp = NULL;
1953 	ext4_group_t flex_group;
1954 	unsigned int groups_per_flex = 0;
1955 	int i, err;
1956 
1957 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1958 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1959 		sbi->s_log_groups_per_flex = 0;
1960 		return 1;
1961 	}
1962 	groups_per_flex = 1U << sbi->s_log_groups_per_flex;
1963 
1964 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1965 	if (err)
1966 		goto failed;
1967 
1968 	for (i = 0; i < sbi->s_groups_count; i++) {
1969 		gdp = ext4_get_group_desc(sb, i, NULL);
1970 
1971 		flex_group = ext4_flex_group(sbi, i);
1972 		atomic_add(ext4_free_inodes_count(sb, gdp),
1973 			   &sbi->s_flex_groups[flex_group].free_inodes);
1974 		atomic_add(ext4_free_group_clusters(sb, gdp),
1975 			   &sbi->s_flex_groups[flex_group].free_clusters);
1976 		atomic_add(ext4_used_dirs_count(sb, gdp),
1977 			   &sbi->s_flex_groups[flex_group].used_dirs);
1978 	}
1979 
1980 	return 1;
1981 failed:
1982 	return 0;
1983 }
1984 
1985 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1986 				   struct ext4_group_desc *gdp)
1987 {
1988 	int offset;
1989 	__u16 crc = 0;
1990 	__le32 le_group = cpu_to_le32(block_group);
1991 
1992 	if ((sbi->s_es->s_feature_ro_compat &
1993 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1994 		/* Use new metadata_csum algorithm */
1995 		__u16 old_csum;
1996 		__u32 csum32;
1997 
1998 		old_csum = gdp->bg_checksum;
1999 		gdp->bg_checksum = 0;
2000 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2001 				     sizeof(le_group));
2002 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2003 				     sbi->s_desc_size);
2004 		gdp->bg_checksum = old_csum;
2005 
2006 		crc = csum32 & 0xFFFF;
2007 		goto out;
2008 	}
2009 
2010 	/* old crc16 code */
2011 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2012 
2013 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2014 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2015 	crc = crc16(crc, (__u8 *)gdp, offset);
2016 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2017 	/* for checksum of struct ext4_group_desc do the rest...*/
2018 	if ((sbi->s_es->s_feature_incompat &
2019 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2020 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2021 		crc = crc16(crc, (__u8 *)gdp + offset,
2022 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2023 				offset);
2024 
2025 out:
2026 	return cpu_to_le16(crc);
2027 }
2028 
2029 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2030 				struct ext4_group_desc *gdp)
2031 {
2032 	if (ext4_has_group_desc_csum(sb) &&
2033 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2034 						      block_group, gdp)))
2035 		return 0;
2036 
2037 	return 1;
2038 }
2039 
2040 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2041 			      struct ext4_group_desc *gdp)
2042 {
2043 	if (!ext4_has_group_desc_csum(sb))
2044 		return;
2045 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2046 }
2047 
2048 /* Called at mount-time, super-block is locked */
2049 static int ext4_check_descriptors(struct super_block *sb,
2050 				  ext4_group_t *first_not_zeroed)
2051 {
2052 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2053 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2054 	ext4_fsblk_t last_block;
2055 	ext4_fsblk_t block_bitmap;
2056 	ext4_fsblk_t inode_bitmap;
2057 	ext4_fsblk_t inode_table;
2058 	int flexbg_flag = 0;
2059 	ext4_group_t i, grp = sbi->s_groups_count;
2060 
2061 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2062 		flexbg_flag = 1;
2063 
2064 	ext4_debug("Checking group descriptors");
2065 
2066 	for (i = 0; i < sbi->s_groups_count; i++) {
2067 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2068 
2069 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2070 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2071 		else
2072 			last_block = first_block +
2073 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2074 
2075 		if ((grp == sbi->s_groups_count) &&
2076 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2077 			grp = i;
2078 
2079 		block_bitmap = ext4_block_bitmap(sb, gdp);
2080 		if (block_bitmap < first_block || block_bitmap > last_block) {
2081 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2082 			       "Block bitmap for group %u not in group "
2083 			       "(block %llu)!", i, block_bitmap);
2084 			return 0;
2085 		}
2086 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2087 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2088 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2089 			       "Inode bitmap for group %u not in group "
2090 			       "(block %llu)!", i, inode_bitmap);
2091 			return 0;
2092 		}
2093 		inode_table = ext4_inode_table(sb, gdp);
2094 		if (inode_table < first_block ||
2095 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2096 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2097 			       "Inode table for group %u not in group "
2098 			       "(block %llu)!", i, inode_table);
2099 			return 0;
2100 		}
2101 		ext4_lock_group(sb, i);
2102 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2103 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2104 				 "Checksum for group %u failed (%u!=%u)",
2105 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2106 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2107 			if (!(sb->s_flags & MS_RDONLY)) {
2108 				ext4_unlock_group(sb, i);
2109 				return 0;
2110 			}
2111 		}
2112 		ext4_unlock_group(sb, i);
2113 		if (!flexbg_flag)
2114 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2115 	}
2116 	if (NULL != first_not_zeroed)
2117 		*first_not_zeroed = grp;
2118 
2119 	ext4_free_blocks_count_set(sbi->s_es,
2120 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2121 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2122 	return 1;
2123 }
2124 
2125 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2126  * the superblock) which were deleted from all directories, but held open by
2127  * a process at the time of a crash.  We walk the list and try to delete these
2128  * inodes at recovery time (only with a read-write filesystem).
2129  *
2130  * In order to keep the orphan inode chain consistent during traversal (in
2131  * case of crash during recovery), we link each inode into the superblock
2132  * orphan list_head and handle it the same way as an inode deletion during
2133  * normal operation (which journals the operations for us).
2134  *
2135  * We only do an iget() and an iput() on each inode, which is very safe if we
2136  * accidentally point at an in-use or already deleted inode.  The worst that
2137  * can happen in this case is that we get a "bit already cleared" message from
2138  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2139  * e2fsck was run on this filesystem, and it must have already done the orphan
2140  * inode cleanup for us, so we can safely abort without any further action.
2141  */
2142 static void ext4_orphan_cleanup(struct super_block *sb,
2143 				struct ext4_super_block *es)
2144 {
2145 	unsigned int s_flags = sb->s_flags;
2146 	int nr_orphans = 0, nr_truncates = 0;
2147 #ifdef CONFIG_QUOTA
2148 	int i;
2149 #endif
2150 	if (!es->s_last_orphan) {
2151 		jbd_debug(4, "no orphan inodes to clean up\n");
2152 		return;
2153 	}
2154 
2155 	if (bdev_read_only(sb->s_bdev)) {
2156 		ext4_msg(sb, KERN_ERR, "write access "
2157 			"unavailable, skipping orphan cleanup");
2158 		return;
2159 	}
2160 
2161 	/* Check if feature set would not allow a r/w mount */
2162 	if (!ext4_feature_set_ok(sb, 0)) {
2163 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2164 			 "unknown ROCOMPAT features");
2165 		return;
2166 	}
2167 
2168 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2169 		/* don't clear list on RO mount w/ errors */
2170 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2171 			jbd_debug(1, "Errors on filesystem, "
2172 				  "clearing orphan list.\n");
2173 			es->s_last_orphan = 0;
2174 		}
2175 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2176 		return;
2177 	}
2178 
2179 	if (s_flags & MS_RDONLY) {
2180 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2181 		sb->s_flags &= ~MS_RDONLY;
2182 	}
2183 #ifdef CONFIG_QUOTA
2184 	/* Needed for iput() to work correctly and not trash data */
2185 	sb->s_flags |= MS_ACTIVE;
2186 	/* Turn on quotas so that they are updated correctly */
2187 	for (i = 0; i < MAXQUOTAS; i++) {
2188 		if (EXT4_SB(sb)->s_qf_names[i]) {
2189 			int ret = ext4_quota_on_mount(sb, i);
2190 			if (ret < 0)
2191 				ext4_msg(sb, KERN_ERR,
2192 					"Cannot turn on journaled "
2193 					"quota: error %d", ret);
2194 		}
2195 	}
2196 #endif
2197 
2198 	while (es->s_last_orphan) {
2199 		struct inode *inode;
2200 
2201 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2202 		if (IS_ERR(inode)) {
2203 			es->s_last_orphan = 0;
2204 			break;
2205 		}
2206 
2207 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2208 		dquot_initialize(inode);
2209 		if (inode->i_nlink) {
2210 			ext4_msg(sb, KERN_DEBUG,
2211 				"%s: truncating inode %lu to %lld bytes",
2212 				__func__, inode->i_ino, inode->i_size);
2213 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2214 				  inode->i_ino, inode->i_size);
2215 			ext4_truncate(inode);
2216 			nr_truncates++;
2217 		} else {
2218 			ext4_msg(sb, KERN_DEBUG,
2219 				"%s: deleting unreferenced inode %lu",
2220 				__func__, inode->i_ino);
2221 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2222 				  inode->i_ino);
2223 			nr_orphans++;
2224 		}
2225 		iput(inode);  /* The delete magic happens here! */
2226 	}
2227 
2228 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2229 
2230 	if (nr_orphans)
2231 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2232 		       PLURAL(nr_orphans));
2233 	if (nr_truncates)
2234 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2235 		       PLURAL(nr_truncates));
2236 #ifdef CONFIG_QUOTA
2237 	/* Turn quotas off */
2238 	for (i = 0; i < MAXQUOTAS; i++) {
2239 		if (sb_dqopt(sb)->files[i])
2240 			dquot_quota_off(sb, i);
2241 	}
2242 #endif
2243 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2244 }
2245 
2246 /*
2247  * Maximal extent format file size.
2248  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2249  * extent format containers, within a sector_t, and within i_blocks
2250  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2251  * so that won't be a limiting factor.
2252  *
2253  * However there is other limiting factor. We do store extents in the form
2254  * of starting block and length, hence the resulting length of the extent
2255  * covering maximum file size must fit into on-disk format containers as
2256  * well. Given that length is always by 1 unit bigger than max unit (because
2257  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2258  *
2259  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2260  */
2261 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2262 {
2263 	loff_t res;
2264 	loff_t upper_limit = MAX_LFS_FILESIZE;
2265 
2266 	/* small i_blocks in vfs inode? */
2267 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2268 		/*
2269 		 * CONFIG_LBDAF is not enabled implies the inode
2270 		 * i_block represent total blocks in 512 bytes
2271 		 * 32 == size of vfs inode i_blocks * 8
2272 		 */
2273 		upper_limit = (1LL << 32) - 1;
2274 
2275 		/* total blocks in file system block size */
2276 		upper_limit >>= (blkbits - 9);
2277 		upper_limit <<= blkbits;
2278 	}
2279 
2280 	/*
2281 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2282 	 * by one fs block, so ee_len can cover the extent of maximum file
2283 	 * size
2284 	 */
2285 	res = (1LL << 32) - 1;
2286 	res <<= blkbits;
2287 
2288 	/* Sanity check against vm- & vfs- imposed limits */
2289 	if (res > upper_limit)
2290 		res = upper_limit;
2291 
2292 	return res;
2293 }
2294 
2295 /*
2296  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2297  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2298  * We need to be 1 filesystem block less than the 2^48 sector limit.
2299  */
2300 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2301 {
2302 	loff_t res = EXT4_NDIR_BLOCKS;
2303 	int meta_blocks;
2304 	loff_t upper_limit;
2305 	/* This is calculated to be the largest file size for a dense, block
2306 	 * mapped file such that the file's total number of 512-byte sectors,
2307 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2308 	 *
2309 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2310 	 * number of 512-byte sectors of the file.
2311 	 */
2312 
2313 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2314 		/*
2315 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2316 		 * the inode i_block field represents total file blocks in
2317 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2318 		 */
2319 		upper_limit = (1LL << 32) - 1;
2320 
2321 		/* total blocks in file system block size */
2322 		upper_limit >>= (bits - 9);
2323 
2324 	} else {
2325 		/*
2326 		 * We use 48 bit ext4_inode i_blocks
2327 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2328 		 * represent total number of blocks in
2329 		 * file system block size
2330 		 */
2331 		upper_limit = (1LL << 48) - 1;
2332 
2333 	}
2334 
2335 	/* indirect blocks */
2336 	meta_blocks = 1;
2337 	/* double indirect blocks */
2338 	meta_blocks += 1 + (1LL << (bits-2));
2339 	/* tripple indirect blocks */
2340 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2341 
2342 	upper_limit -= meta_blocks;
2343 	upper_limit <<= bits;
2344 
2345 	res += 1LL << (bits-2);
2346 	res += 1LL << (2*(bits-2));
2347 	res += 1LL << (3*(bits-2));
2348 	res <<= bits;
2349 	if (res > upper_limit)
2350 		res = upper_limit;
2351 
2352 	if (res > MAX_LFS_FILESIZE)
2353 		res = MAX_LFS_FILESIZE;
2354 
2355 	return res;
2356 }
2357 
2358 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2359 				   ext4_fsblk_t logical_sb_block, int nr)
2360 {
2361 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2362 	ext4_group_t bg, first_meta_bg;
2363 	int has_super = 0;
2364 
2365 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2366 
2367 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2368 	    nr < first_meta_bg)
2369 		return logical_sb_block + nr + 1;
2370 	bg = sbi->s_desc_per_block * nr;
2371 	if (ext4_bg_has_super(sb, bg))
2372 		has_super = 1;
2373 
2374 	return (has_super + ext4_group_first_block_no(sb, bg));
2375 }
2376 
2377 /**
2378  * ext4_get_stripe_size: Get the stripe size.
2379  * @sbi: In memory super block info
2380  *
2381  * If we have specified it via mount option, then
2382  * use the mount option value. If the value specified at mount time is
2383  * greater than the blocks per group use the super block value.
2384  * If the super block value is greater than blocks per group return 0.
2385  * Allocator needs it be less than blocks per group.
2386  *
2387  */
2388 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2389 {
2390 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2391 	unsigned long stripe_width =
2392 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2393 	int ret;
2394 
2395 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2396 		ret = sbi->s_stripe;
2397 	else if (stripe_width <= sbi->s_blocks_per_group)
2398 		ret = stripe_width;
2399 	else if (stride <= sbi->s_blocks_per_group)
2400 		ret = stride;
2401 	else
2402 		ret = 0;
2403 
2404 	/*
2405 	 * If the stripe width is 1, this makes no sense and
2406 	 * we set it to 0 to turn off stripe handling code.
2407 	 */
2408 	if (ret <= 1)
2409 		ret = 0;
2410 
2411 	return ret;
2412 }
2413 
2414 /* sysfs supprt */
2415 
2416 struct ext4_attr {
2417 	struct attribute attr;
2418 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2419 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2420 			 const char *, size_t);
2421 	int offset;
2422 };
2423 
2424 static int parse_strtoul(const char *buf,
2425 		unsigned long max, unsigned long *value)
2426 {
2427 	char *endp;
2428 
2429 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2430 	endp = skip_spaces(endp);
2431 	if (*endp || *value > max)
2432 		return -EINVAL;
2433 
2434 	return 0;
2435 }
2436 
2437 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2438 					      struct ext4_sb_info *sbi,
2439 					      char *buf)
2440 {
2441 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2442 		(s64) EXT4_C2B(sbi,
2443 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2444 }
2445 
2446 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2447 					 struct ext4_sb_info *sbi, char *buf)
2448 {
2449 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2450 
2451 	if (!sb->s_bdev->bd_part)
2452 		return snprintf(buf, PAGE_SIZE, "0\n");
2453 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2454 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2455 			 sbi->s_sectors_written_start) >> 1);
2456 }
2457 
2458 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2459 					  struct ext4_sb_info *sbi, char *buf)
2460 {
2461 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2462 
2463 	if (!sb->s_bdev->bd_part)
2464 		return snprintf(buf, PAGE_SIZE, "0\n");
2465 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2466 			(unsigned long long)(sbi->s_kbytes_written +
2467 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2468 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2469 }
2470 
2471 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2472 					  struct ext4_sb_info *sbi,
2473 					  const char *buf, size_t count)
2474 {
2475 	unsigned long t;
2476 
2477 	if (parse_strtoul(buf, 0x40000000, &t))
2478 		return -EINVAL;
2479 
2480 	if (t && !is_power_of_2(t))
2481 		return -EINVAL;
2482 
2483 	sbi->s_inode_readahead_blks = t;
2484 	return count;
2485 }
2486 
2487 static ssize_t sbi_ui_show(struct ext4_attr *a,
2488 			   struct ext4_sb_info *sbi, char *buf)
2489 {
2490 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2491 
2492 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2493 }
2494 
2495 static ssize_t sbi_ui_store(struct ext4_attr *a,
2496 			    struct ext4_sb_info *sbi,
2497 			    const char *buf, size_t count)
2498 {
2499 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2500 	unsigned long t;
2501 
2502 	if (parse_strtoul(buf, 0xffffffff, &t))
2503 		return -EINVAL;
2504 	*ui = t;
2505 	return count;
2506 }
2507 
2508 static ssize_t trigger_test_error(struct ext4_attr *a,
2509 				  struct ext4_sb_info *sbi,
2510 				  const char *buf, size_t count)
2511 {
2512 	int len = count;
2513 
2514 	if (!capable(CAP_SYS_ADMIN))
2515 		return -EPERM;
2516 
2517 	if (len && buf[len-1] == '\n')
2518 		len--;
2519 
2520 	if (len)
2521 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2522 	return count;
2523 }
2524 
2525 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2526 static struct ext4_attr ext4_attr_##_name = {			\
2527 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2528 	.show	= _show,					\
2529 	.store	= _store,					\
2530 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2531 }
2532 #define EXT4_ATTR(name, mode, show, store) \
2533 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2534 
2535 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2536 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2537 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2538 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2539 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2540 #define ATTR_LIST(name) &ext4_attr_##name.attr
2541 
2542 EXT4_RO_ATTR(delayed_allocation_blocks);
2543 EXT4_RO_ATTR(session_write_kbytes);
2544 EXT4_RO_ATTR(lifetime_write_kbytes);
2545 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2546 		 inode_readahead_blks_store, s_inode_readahead_blks);
2547 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2548 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2549 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2550 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2551 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2552 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2553 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2554 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2555 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2556 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2557 
2558 static struct attribute *ext4_attrs[] = {
2559 	ATTR_LIST(delayed_allocation_blocks),
2560 	ATTR_LIST(session_write_kbytes),
2561 	ATTR_LIST(lifetime_write_kbytes),
2562 	ATTR_LIST(inode_readahead_blks),
2563 	ATTR_LIST(inode_goal),
2564 	ATTR_LIST(mb_stats),
2565 	ATTR_LIST(mb_max_to_scan),
2566 	ATTR_LIST(mb_min_to_scan),
2567 	ATTR_LIST(mb_order2_req),
2568 	ATTR_LIST(mb_stream_req),
2569 	ATTR_LIST(mb_group_prealloc),
2570 	ATTR_LIST(max_writeback_mb_bump),
2571 	ATTR_LIST(extent_max_zeroout_kb),
2572 	ATTR_LIST(trigger_fs_error),
2573 	NULL,
2574 };
2575 
2576 /* Features this copy of ext4 supports */
2577 EXT4_INFO_ATTR(lazy_itable_init);
2578 EXT4_INFO_ATTR(batched_discard);
2579 EXT4_INFO_ATTR(meta_bg_resize);
2580 
2581 static struct attribute *ext4_feat_attrs[] = {
2582 	ATTR_LIST(lazy_itable_init),
2583 	ATTR_LIST(batched_discard),
2584 	ATTR_LIST(meta_bg_resize),
2585 	NULL,
2586 };
2587 
2588 static ssize_t ext4_attr_show(struct kobject *kobj,
2589 			      struct attribute *attr, char *buf)
2590 {
2591 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2592 						s_kobj);
2593 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2594 
2595 	return a->show ? a->show(a, sbi, buf) : 0;
2596 }
2597 
2598 static ssize_t ext4_attr_store(struct kobject *kobj,
2599 			       struct attribute *attr,
2600 			       const char *buf, size_t len)
2601 {
2602 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2603 						s_kobj);
2604 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2605 
2606 	return a->store ? a->store(a, sbi, buf, len) : 0;
2607 }
2608 
2609 static void ext4_sb_release(struct kobject *kobj)
2610 {
2611 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2612 						s_kobj);
2613 	complete(&sbi->s_kobj_unregister);
2614 }
2615 
2616 static const struct sysfs_ops ext4_attr_ops = {
2617 	.show	= ext4_attr_show,
2618 	.store	= ext4_attr_store,
2619 };
2620 
2621 static struct kobj_type ext4_ktype = {
2622 	.default_attrs	= ext4_attrs,
2623 	.sysfs_ops	= &ext4_attr_ops,
2624 	.release	= ext4_sb_release,
2625 };
2626 
2627 static void ext4_feat_release(struct kobject *kobj)
2628 {
2629 	complete(&ext4_feat->f_kobj_unregister);
2630 }
2631 
2632 static struct kobj_type ext4_feat_ktype = {
2633 	.default_attrs	= ext4_feat_attrs,
2634 	.sysfs_ops	= &ext4_attr_ops,
2635 	.release	= ext4_feat_release,
2636 };
2637 
2638 /*
2639  * Check whether this filesystem can be mounted based on
2640  * the features present and the RDONLY/RDWR mount requested.
2641  * Returns 1 if this filesystem can be mounted as requested,
2642  * 0 if it cannot be.
2643  */
2644 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2645 {
2646 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2647 		ext4_msg(sb, KERN_ERR,
2648 			"Couldn't mount because of "
2649 			"unsupported optional features (%x)",
2650 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2651 			~EXT4_FEATURE_INCOMPAT_SUPP));
2652 		return 0;
2653 	}
2654 
2655 	if (readonly)
2656 		return 1;
2657 
2658 	/* Check that feature set is OK for a read-write mount */
2659 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2660 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2661 			 "unsupported optional features (%x)",
2662 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2663 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2664 		return 0;
2665 	}
2666 	/*
2667 	 * Large file size enabled file system can only be mounted
2668 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2669 	 */
2670 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2671 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2672 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2673 				 "cannot be mounted RDWR without "
2674 				 "CONFIG_LBDAF");
2675 			return 0;
2676 		}
2677 	}
2678 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2679 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2680 		ext4_msg(sb, KERN_ERR,
2681 			 "Can't support bigalloc feature without "
2682 			 "extents feature\n");
2683 		return 0;
2684 	}
2685 
2686 #ifndef CONFIG_QUOTA
2687 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2688 	    !readonly) {
2689 		ext4_msg(sb, KERN_ERR,
2690 			 "Filesystem with quota feature cannot be mounted RDWR "
2691 			 "without CONFIG_QUOTA");
2692 		return 0;
2693 	}
2694 #endif  /* CONFIG_QUOTA */
2695 	return 1;
2696 }
2697 
2698 /*
2699  * This function is called once a day if we have errors logged
2700  * on the file system
2701  */
2702 static void print_daily_error_info(unsigned long arg)
2703 {
2704 	struct super_block *sb = (struct super_block *) arg;
2705 	struct ext4_sb_info *sbi;
2706 	struct ext4_super_block *es;
2707 
2708 	sbi = EXT4_SB(sb);
2709 	es = sbi->s_es;
2710 
2711 	if (es->s_error_count)
2712 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2713 			 le32_to_cpu(es->s_error_count));
2714 	if (es->s_first_error_time) {
2715 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2716 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2717 		       (int) sizeof(es->s_first_error_func),
2718 		       es->s_first_error_func,
2719 		       le32_to_cpu(es->s_first_error_line));
2720 		if (es->s_first_error_ino)
2721 			printk(": inode %u",
2722 			       le32_to_cpu(es->s_first_error_ino));
2723 		if (es->s_first_error_block)
2724 			printk(": block %llu", (unsigned long long)
2725 			       le64_to_cpu(es->s_first_error_block));
2726 		printk("\n");
2727 	}
2728 	if (es->s_last_error_time) {
2729 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2730 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2731 		       (int) sizeof(es->s_last_error_func),
2732 		       es->s_last_error_func,
2733 		       le32_to_cpu(es->s_last_error_line));
2734 		if (es->s_last_error_ino)
2735 			printk(": inode %u",
2736 			       le32_to_cpu(es->s_last_error_ino));
2737 		if (es->s_last_error_block)
2738 			printk(": block %llu", (unsigned long long)
2739 			       le64_to_cpu(es->s_last_error_block));
2740 		printk("\n");
2741 	}
2742 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2743 }
2744 
2745 /* Find next suitable group and run ext4_init_inode_table */
2746 static int ext4_run_li_request(struct ext4_li_request *elr)
2747 {
2748 	struct ext4_group_desc *gdp = NULL;
2749 	ext4_group_t group, ngroups;
2750 	struct super_block *sb;
2751 	unsigned long timeout = 0;
2752 	int ret = 0;
2753 
2754 	sb = elr->lr_super;
2755 	ngroups = EXT4_SB(sb)->s_groups_count;
2756 
2757 	sb_start_write(sb);
2758 	for (group = elr->lr_next_group; group < ngroups; group++) {
2759 		gdp = ext4_get_group_desc(sb, group, NULL);
2760 		if (!gdp) {
2761 			ret = 1;
2762 			break;
2763 		}
2764 
2765 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2766 			break;
2767 	}
2768 
2769 	if (group == ngroups)
2770 		ret = 1;
2771 
2772 	if (!ret) {
2773 		timeout = jiffies;
2774 		ret = ext4_init_inode_table(sb, group,
2775 					    elr->lr_timeout ? 0 : 1);
2776 		if (elr->lr_timeout == 0) {
2777 			timeout = (jiffies - timeout) *
2778 				  elr->lr_sbi->s_li_wait_mult;
2779 			elr->lr_timeout = timeout;
2780 		}
2781 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2782 		elr->lr_next_group = group + 1;
2783 	}
2784 	sb_end_write(sb);
2785 
2786 	return ret;
2787 }
2788 
2789 /*
2790  * Remove lr_request from the list_request and free the
2791  * request structure. Should be called with li_list_mtx held
2792  */
2793 static void ext4_remove_li_request(struct ext4_li_request *elr)
2794 {
2795 	struct ext4_sb_info *sbi;
2796 
2797 	if (!elr)
2798 		return;
2799 
2800 	sbi = elr->lr_sbi;
2801 
2802 	list_del(&elr->lr_request);
2803 	sbi->s_li_request = NULL;
2804 	kfree(elr);
2805 }
2806 
2807 static void ext4_unregister_li_request(struct super_block *sb)
2808 {
2809 	mutex_lock(&ext4_li_mtx);
2810 	if (!ext4_li_info) {
2811 		mutex_unlock(&ext4_li_mtx);
2812 		return;
2813 	}
2814 
2815 	mutex_lock(&ext4_li_info->li_list_mtx);
2816 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2817 	mutex_unlock(&ext4_li_info->li_list_mtx);
2818 	mutex_unlock(&ext4_li_mtx);
2819 }
2820 
2821 static struct task_struct *ext4_lazyinit_task;
2822 
2823 /*
2824  * This is the function where ext4lazyinit thread lives. It walks
2825  * through the request list searching for next scheduled filesystem.
2826  * When such a fs is found, run the lazy initialization request
2827  * (ext4_rn_li_request) and keep track of the time spend in this
2828  * function. Based on that time we compute next schedule time of
2829  * the request. When walking through the list is complete, compute
2830  * next waking time and put itself into sleep.
2831  */
2832 static int ext4_lazyinit_thread(void *arg)
2833 {
2834 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2835 	struct list_head *pos, *n;
2836 	struct ext4_li_request *elr;
2837 	unsigned long next_wakeup, cur;
2838 
2839 	BUG_ON(NULL == eli);
2840 
2841 cont_thread:
2842 	while (true) {
2843 		next_wakeup = MAX_JIFFY_OFFSET;
2844 
2845 		mutex_lock(&eli->li_list_mtx);
2846 		if (list_empty(&eli->li_request_list)) {
2847 			mutex_unlock(&eli->li_list_mtx);
2848 			goto exit_thread;
2849 		}
2850 
2851 		list_for_each_safe(pos, n, &eli->li_request_list) {
2852 			elr = list_entry(pos, struct ext4_li_request,
2853 					 lr_request);
2854 
2855 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2856 				if (ext4_run_li_request(elr) != 0) {
2857 					/* error, remove the lazy_init job */
2858 					ext4_remove_li_request(elr);
2859 					continue;
2860 				}
2861 			}
2862 
2863 			if (time_before(elr->lr_next_sched, next_wakeup))
2864 				next_wakeup = elr->lr_next_sched;
2865 		}
2866 		mutex_unlock(&eli->li_list_mtx);
2867 
2868 		try_to_freeze();
2869 
2870 		cur = jiffies;
2871 		if ((time_after_eq(cur, next_wakeup)) ||
2872 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2873 			cond_resched();
2874 			continue;
2875 		}
2876 
2877 		schedule_timeout_interruptible(next_wakeup - cur);
2878 
2879 		if (kthread_should_stop()) {
2880 			ext4_clear_request_list();
2881 			goto exit_thread;
2882 		}
2883 	}
2884 
2885 exit_thread:
2886 	/*
2887 	 * It looks like the request list is empty, but we need
2888 	 * to check it under the li_list_mtx lock, to prevent any
2889 	 * additions into it, and of course we should lock ext4_li_mtx
2890 	 * to atomically free the list and ext4_li_info, because at
2891 	 * this point another ext4 filesystem could be registering
2892 	 * new one.
2893 	 */
2894 	mutex_lock(&ext4_li_mtx);
2895 	mutex_lock(&eli->li_list_mtx);
2896 	if (!list_empty(&eli->li_request_list)) {
2897 		mutex_unlock(&eli->li_list_mtx);
2898 		mutex_unlock(&ext4_li_mtx);
2899 		goto cont_thread;
2900 	}
2901 	mutex_unlock(&eli->li_list_mtx);
2902 	kfree(ext4_li_info);
2903 	ext4_li_info = NULL;
2904 	mutex_unlock(&ext4_li_mtx);
2905 
2906 	return 0;
2907 }
2908 
2909 static void ext4_clear_request_list(void)
2910 {
2911 	struct list_head *pos, *n;
2912 	struct ext4_li_request *elr;
2913 
2914 	mutex_lock(&ext4_li_info->li_list_mtx);
2915 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2916 		elr = list_entry(pos, struct ext4_li_request,
2917 				 lr_request);
2918 		ext4_remove_li_request(elr);
2919 	}
2920 	mutex_unlock(&ext4_li_info->li_list_mtx);
2921 }
2922 
2923 static int ext4_run_lazyinit_thread(void)
2924 {
2925 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2926 					 ext4_li_info, "ext4lazyinit");
2927 	if (IS_ERR(ext4_lazyinit_task)) {
2928 		int err = PTR_ERR(ext4_lazyinit_task);
2929 		ext4_clear_request_list();
2930 		kfree(ext4_li_info);
2931 		ext4_li_info = NULL;
2932 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2933 				 "initialization thread\n",
2934 				 err);
2935 		return err;
2936 	}
2937 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2938 	return 0;
2939 }
2940 
2941 /*
2942  * Check whether it make sense to run itable init. thread or not.
2943  * If there is at least one uninitialized inode table, return
2944  * corresponding group number, else the loop goes through all
2945  * groups and return total number of groups.
2946  */
2947 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2948 {
2949 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2950 	struct ext4_group_desc *gdp = NULL;
2951 
2952 	for (group = 0; group < ngroups; group++) {
2953 		gdp = ext4_get_group_desc(sb, group, NULL);
2954 		if (!gdp)
2955 			continue;
2956 
2957 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2958 			break;
2959 	}
2960 
2961 	return group;
2962 }
2963 
2964 static int ext4_li_info_new(void)
2965 {
2966 	struct ext4_lazy_init *eli = NULL;
2967 
2968 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2969 	if (!eli)
2970 		return -ENOMEM;
2971 
2972 	INIT_LIST_HEAD(&eli->li_request_list);
2973 	mutex_init(&eli->li_list_mtx);
2974 
2975 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2976 
2977 	ext4_li_info = eli;
2978 
2979 	return 0;
2980 }
2981 
2982 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2983 					    ext4_group_t start)
2984 {
2985 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2986 	struct ext4_li_request *elr;
2987 	unsigned long rnd;
2988 
2989 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2990 	if (!elr)
2991 		return NULL;
2992 
2993 	elr->lr_super = sb;
2994 	elr->lr_sbi = sbi;
2995 	elr->lr_next_group = start;
2996 
2997 	/*
2998 	 * Randomize first schedule time of the request to
2999 	 * spread the inode table initialization requests
3000 	 * better.
3001 	 */
3002 	get_random_bytes(&rnd, sizeof(rnd));
3003 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
3004 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3005 
3006 	return elr;
3007 }
3008 
3009 static int ext4_register_li_request(struct super_block *sb,
3010 				    ext4_group_t first_not_zeroed)
3011 {
3012 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3013 	struct ext4_li_request *elr;
3014 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3015 	int ret = 0;
3016 
3017 	if (sbi->s_li_request != NULL) {
3018 		/*
3019 		 * Reset timeout so it can be computed again, because
3020 		 * s_li_wait_mult might have changed.
3021 		 */
3022 		sbi->s_li_request->lr_timeout = 0;
3023 		return 0;
3024 	}
3025 
3026 	if (first_not_zeroed == ngroups ||
3027 	    (sb->s_flags & MS_RDONLY) ||
3028 	    !test_opt(sb, INIT_INODE_TABLE))
3029 		return 0;
3030 
3031 	elr = ext4_li_request_new(sb, first_not_zeroed);
3032 	if (!elr)
3033 		return -ENOMEM;
3034 
3035 	mutex_lock(&ext4_li_mtx);
3036 
3037 	if (NULL == ext4_li_info) {
3038 		ret = ext4_li_info_new();
3039 		if (ret)
3040 			goto out;
3041 	}
3042 
3043 	mutex_lock(&ext4_li_info->li_list_mtx);
3044 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3045 	mutex_unlock(&ext4_li_info->li_list_mtx);
3046 
3047 	sbi->s_li_request = elr;
3048 	/*
3049 	 * set elr to NULL here since it has been inserted to
3050 	 * the request_list and the removal and free of it is
3051 	 * handled by ext4_clear_request_list from now on.
3052 	 */
3053 	elr = NULL;
3054 
3055 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3056 		ret = ext4_run_lazyinit_thread();
3057 		if (ret)
3058 			goto out;
3059 	}
3060 out:
3061 	mutex_unlock(&ext4_li_mtx);
3062 	if (ret)
3063 		kfree(elr);
3064 	return ret;
3065 }
3066 
3067 /*
3068  * We do not need to lock anything since this is called on
3069  * module unload.
3070  */
3071 static void ext4_destroy_lazyinit_thread(void)
3072 {
3073 	/*
3074 	 * If thread exited earlier
3075 	 * there's nothing to be done.
3076 	 */
3077 	if (!ext4_li_info || !ext4_lazyinit_task)
3078 		return;
3079 
3080 	kthread_stop(ext4_lazyinit_task);
3081 }
3082 
3083 static int set_journal_csum_feature_set(struct super_block *sb)
3084 {
3085 	int ret = 1;
3086 	int compat, incompat;
3087 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3088 
3089 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3090 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3091 		/* journal checksum v2 */
3092 		compat = 0;
3093 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3094 	} else {
3095 		/* journal checksum v1 */
3096 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3097 		incompat = 0;
3098 	}
3099 
3100 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3101 		ret = jbd2_journal_set_features(sbi->s_journal,
3102 				compat, 0,
3103 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3104 				incompat);
3105 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3106 		ret = jbd2_journal_set_features(sbi->s_journal,
3107 				compat, 0,
3108 				incompat);
3109 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3110 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3111 	} else {
3112 		jbd2_journal_clear_features(sbi->s_journal,
3113 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3114 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3115 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3116 	}
3117 
3118 	return ret;
3119 }
3120 
3121 /*
3122  * Note: calculating the overhead so we can be compatible with
3123  * historical BSD practice is quite difficult in the face of
3124  * clusters/bigalloc.  This is because multiple metadata blocks from
3125  * different block group can end up in the same allocation cluster.
3126  * Calculating the exact overhead in the face of clustered allocation
3127  * requires either O(all block bitmaps) in memory or O(number of block
3128  * groups**2) in time.  We will still calculate the superblock for
3129  * older file systems --- and if we come across with a bigalloc file
3130  * system with zero in s_overhead_clusters the estimate will be close to
3131  * correct especially for very large cluster sizes --- but for newer
3132  * file systems, it's better to calculate this figure once at mkfs
3133  * time, and store it in the superblock.  If the superblock value is
3134  * present (even for non-bigalloc file systems), we will use it.
3135  */
3136 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3137 			  char *buf)
3138 {
3139 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3140 	struct ext4_group_desc	*gdp;
3141 	ext4_fsblk_t		first_block, last_block, b;
3142 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3143 	int			s, j, count = 0;
3144 
3145 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3146 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3147 			sbi->s_itb_per_group + 2);
3148 
3149 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3150 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3151 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3152 	for (i = 0; i < ngroups; i++) {
3153 		gdp = ext4_get_group_desc(sb, i, NULL);
3154 		b = ext4_block_bitmap(sb, gdp);
3155 		if (b >= first_block && b <= last_block) {
3156 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3157 			count++;
3158 		}
3159 		b = ext4_inode_bitmap(sb, gdp);
3160 		if (b >= first_block && b <= last_block) {
3161 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3162 			count++;
3163 		}
3164 		b = ext4_inode_table(sb, gdp);
3165 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3166 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3167 				int c = EXT4_B2C(sbi, b - first_block);
3168 				ext4_set_bit(c, buf);
3169 				count++;
3170 			}
3171 		if (i != grp)
3172 			continue;
3173 		s = 0;
3174 		if (ext4_bg_has_super(sb, grp)) {
3175 			ext4_set_bit(s++, buf);
3176 			count++;
3177 		}
3178 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3179 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3180 			count++;
3181 		}
3182 	}
3183 	if (!count)
3184 		return 0;
3185 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3186 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3187 }
3188 
3189 /*
3190  * Compute the overhead and stash it in sbi->s_overhead
3191  */
3192 int ext4_calculate_overhead(struct super_block *sb)
3193 {
3194 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3195 	struct ext4_super_block *es = sbi->s_es;
3196 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3197 	ext4_fsblk_t overhead = 0;
3198 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3199 
3200 	if (!buf)
3201 		return -ENOMEM;
3202 
3203 	/*
3204 	 * Compute the overhead (FS structures).  This is constant
3205 	 * for a given filesystem unless the number of block groups
3206 	 * changes so we cache the previous value until it does.
3207 	 */
3208 
3209 	/*
3210 	 * All of the blocks before first_data_block are overhead
3211 	 */
3212 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3213 
3214 	/*
3215 	 * Add the overhead found in each block group
3216 	 */
3217 	for (i = 0; i < ngroups; i++) {
3218 		int blks;
3219 
3220 		blks = count_overhead(sb, i, buf);
3221 		overhead += blks;
3222 		if (blks)
3223 			memset(buf, 0, PAGE_SIZE);
3224 		cond_resched();
3225 	}
3226 	sbi->s_overhead = overhead;
3227 	smp_wmb();
3228 	free_page((unsigned long) buf);
3229 	return 0;
3230 }
3231 
3232 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3233 {
3234 	char *orig_data = kstrdup(data, GFP_KERNEL);
3235 	struct buffer_head *bh;
3236 	struct ext4_super_block *es = NULL;
3237 	struct ext4_sb_info *sbi;
3238 	ext4_fsblk_t block;
3239 	ext4_fsblk_t sb_block = get_sb_block(&data);
3240 	ext4_fsblk_t logical_sb_block;
3241 	unsigned long offset = 0;
3242 	unsigned long journal_devnum = 0;
3243 	unsigned long def_mount_opts;
3244 	struct inode *root;
3245 	char *cp;
3246 	const char *descr;
3247 	int ret = -ENOMEM;
3248 	int blocksize, clustersize;
3249 	unsigned int db_count;
3250 	unsigned int i;
3251 	int needs_recovery, has_huge_files, has_bigalloc;
3252 	__u64 blocks_count;
3253 	int err = 0;
3254 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3255 	ext4_group_t first_not_zeroed;
3256 
3257 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3258 	if (!sbi)
3259 		goto out_free_orig;
3260 
3261 	sbi->s_blockgroup_lock =
3262 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3263 	if (!sbi->s_blockgroup_lock) {
3264 		kfree(sbi);
3265 		goto out_free_orig;
3266 	}
3267 	sb->s_fs_info = sbi;
3268 	sbi->s_sb = sb;
3269 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3270 	sbi->s_sb_block = sb_block;
3271 	if (sb->s_bdev->bd_part)
3272 		sbi->s_sectors_written_start =
3273 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3274 
3275 	/* Cleanup superblock name */
3276 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3277 		*cp = '!';
3278 
3279 	/* -EINVAL is default */
3280 	ret = -EINVAL;
3281 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3282 	if (!blocksize) {
3283 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3284 		goto out_fail;
3285 	}
3286 
3287 	/*
3288 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3289 	 * block sizes.  We need to calculate the offset from buffer start.
3290 	 */
3291 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3292 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3293 		offset = do_div(logical_sb_block, blocksize);
3294 	} else {
3295 		logical_sb_block = sb_block;
3296 	}
3297 
3298 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3299 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3300 		goto out_fail;
3301 	}
3302 	/*
3303 	 * Note: s_es must be initialized as soon as possible because
3304 	 *       some ext4 macro-instructions depend on its value
3305 	 */
3306 	es = (struct ext4_super_block *) (bh->b_data + offset);
3307 	sbi->s_es = es;
3308 	sb->s_magic = le16_to_cpu(es->s_magic);
3309 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3310 		goto cantfind_ext4;
3311 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3312 
3313 	/* Warn if metadata_csum and gdt_csum are both set. */
3314 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3315 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3316 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3317 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3318 			     "redundant flags; please run fsck.");
3319 
3320 	/* Check for a known checksum algorithm */
3321 	if (!ext4_verify_csum_type(sb, es)) {
3322 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3323 			 "unknown checksum algorithm.");
3324 		silent = 1;
3325 		goto cantfind_ext4;
3326 	}
3327 
3328 	/* Load the checksum driver */
3329 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3330 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3331 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3332 		if (IS_ERR(sbi->s_chksum_driver)) {
3333 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3334 			ret = PTR_ERR(sbi->s_chksum_driver);
3335 			sbi->s_chksum_driver = NULL;
3336 			goto failed_mount;
3337 		}
3338 	}
3339 
3340 	/* Check superblock checksum */
3341 	if (!ext4_superblock_csum_verify(sb, es)) {
3342 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3343 			 "invalid superblock checksum.  Run e2fsck?");
3344 		silent = 1;
3345 		goto cantfind_ext4;
3346 	}
3347 
3348 	/* Precompute checksum seed for all metadata */
3349 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3350 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3351 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3352 					       sizeof(es->s_uuid));
3353 
3354 	/* Set defaults before we parse the mount options */
3355 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3356 	set_opt(sb, INIT_INODE_TABLE);
3357 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3358 		set_opt(sb, DEBUG);
3359 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3360 		set_opt(sb, GRPID);
3361 	if (def_mount_opts & EXT4_DEFM_UID16)
3362 		set_opt(sb, NO_UID32);
3363 	/* xattr user namespace & acls are now defaulted on */
3364 	set_opt(sb, XATTR_USER);
3365 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3366 	set_opt(sb, POSIX_ACL);
3367 #endif
3368 	set_opt(sb, MBLK_IO_SUBMIT);
3369 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3370 		set_opt(sb, JOURNAL_DATA);
3371 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3372 		set_opt(sb, ORDERED_DATA);
3373 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3374 		set_opt(sb, WRITEBACK_DATA);
3375 
3376 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3377 		set_opt(sb, ERRORS_PANIC);
3378 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3379 		set_opt(sb, ERRORS_CONT);
3380 	else
3381 		set_opt(sb, ERRORS_RO);
3382 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3383 		set_opt(sb, BLOCK_VALIDITY);
3384 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3385 		set_opt(sb, DISCARD);
3386 
3387 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3388 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3389 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3390 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3391 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3392 
3393 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3394 		set_opt(sb, BARRIER);
3395 
3396 	/*
3397 	 * enable delayed allocation by default
3398 	 * Use -o nodelalloc to turn it off
3399 	 */
3400 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3401 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3402 		set_opt(sb, DELALLOC);
3403 
3404 	/*
3405 	 * set default s_li_wait_mult for lazyinit, for the case there is
3406 	 * no mount option specified.
3407 	 */
3408 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3409 
3410 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3411 			   &journal_devnum, &journal_ioprio, 0)) {
3412 		ext4_msg(sb, KERN_WARNING,
3413 			 "failed to parse options in superblock: %s",
3414 			 sbi->s_es->s_mount_opts);
3415 	}
3416 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3417 	if (!parse_options((char *) data, sb, &journal_devnum,
3418 			   &journal_ioprio, 0))
3419 		goto failed_mount;
3420 
3421 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3422 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3423 			    "with data=journal disables delayed "
3424 			    "allocation and O_DIRECT support!\n");
3425 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3426 			ext4_msg(sb, KERN_ERR, "can't mount with "
3427 				 "both data=journal and delalloc");
3428 			goto failed_mount;
3429 		}
3430 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3431 			ext4_msg(sb, KERN_ERR, "can't mount with "
3432 				 "both data=journal and delalloc");
3433 			goto failed_mount;
3434 		}
3435 		if (test_opt(sb, DELALLOC))
3436 			clear_opt(sb, DELALLOC);
3437 	}
3438 
3439 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3440 	if (test_opt(sb, DIOREAD_NOLOCK)) {
3441 		if (blocksize < PAGE_SIZE) {
3442 			ext4_msg(sb, KERN_ERR, "can't mount with "
3443 				 "dioread_nolock if block size != PAGE_SIZE");
3444 			goto failed_mount;
3445 		}
3446 	}
3447 
3448 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3449 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3450 
3451 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3452 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3453 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3454 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3455 		ext4_msg(sb, KERN_WARNING,
3456 		       "feature flags set on rev 0 fs, "
3457 		       "running e2fsck is recommended");
3458 
3459 	if (IS_EXT2_SB(sb)) {
3460 		if (ext2_feature_set_ok(sb))
3461 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3462 				 "using the ext4 subsystem");
3463 		else {
3464 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3465 				 "to feature incompatibilities");
3466 			goto failed_mount;
3467 		}
3468 	}
3469 
3470 	if (IS_EXT3_SB(sb)) {
3471 		if (ext3_feature_set_ok(sb))
3472 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3473 				 "using the ext4 subsystem");
3474 		else {
3475 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3476 				 "to feature incompatibilities");
3477 			goto failed_mount;
3478 		}
3479 	}
3480 
3481 	/*
3482 	 * Check feature flags regardless of the revision level, since we
3483 	 * previously didn't change the revision level when setting the flags,
3484 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3485 	 */
3486 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3487 		goto failed_mount;
3488 
3489 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3490 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3491 		ext4_msg(sb, KERN_ERR,
3492 		       "Unsupported filesystem blocksize %d", blocksize);
3493 		goto failed_mount;
3494 	}
3495 
3496 	if (sb->s_blocksize != blocksize) {
3497 		/* Validate the filesystem blocksize */
3498 		if (!sb_set_blocksize(sb, blocksize)) {
3499 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3500 					blocksize);
3501 			goto failed_mount;
3502 		}
3503 
3504 		brelse(bh);
3505 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3506 		offset = do_div(logical_sb_block, blocksize);
3507 		bh = sb_bread(sb, logical_sb_block);
3508 		if (!bh) {
3509 			ext4_msg(sb, KERN_ERR,
3510 			       "Can't read superblock on 2nd try");
3511 			goto failed_mount;
3512 		}
3513 		es = (struct ext4_super_block *)(bh->b_data + offset);
3514 		sbi->s_es = es;
3515 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3516 			ext4_msg(sb, KERN_ERR,
3517 			       "Magic mismatch, very weird!");
3518 			goto failed_mount;
3519 		}
3520 	}
3521 
3522 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3523 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3524 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3525 						      has_huge_files);
3526 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3527 
3528 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3529 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3530 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3531 	} else {
3532 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3533 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3534 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3535 		    (!is_power_of_2(sbi->s_inode_size)) ||
3536 		    (sbi->s_inode_size > blocksize)) {
3537 			ext4_msg(sb, KERN_ERR,
3538 			       "unsupported inode size: %d",
3539 			       sbi->s_inode_size);
3540 			goto failed_mount;
3541 		}
3542 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3543 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3544 	}
3545 
3546 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3547 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3548 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3549 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3550 		    !is_power_of_2(sbi->s_desc_size)) {
3551 			ext4_msg(sb, KERN_ERR,
3552 			       "unsupported descriptor size %lu",
3553 			       sbi->s_desc_size);
3554 			goto failed_mount;
3555 		}
3556 	} else
3557 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3558 
3559 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3560 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3561 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3562 		goto cantfind_ext4;
3563 
3564 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3565 	if (sbi->s_inodes_per_block == 0)
3566 		goto cantfind_ext4;
3567 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3568 					sbi->s_inodes_per_block;
3569 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3570 	sbi->s_sbh = bh;
3571 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3572 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3573 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3574 
3575 	for (i = 0; i < 4; i++)
3576 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3577 	sbi->s_def_hash_version = es->s_def_hash_version;
3578 	i = le32_to_cpu(es->s_flags);
3579 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3580 		sbi->s_hash_unsigned = 3;
3581 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3582 #ifdef __CHAR_UNSIGNED__
3583 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3584 		sbi->s_hash_unsigned = 3;
3585 #else
3586 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3587 #endif
3588 	}
3589 
3590 	/* Handle clustersize */
3591 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3592 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3593 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3594 	if (has_bigalloc) {
3595 		if (clustersize < blocksize) {
3596 			ext4_msg(sb, KERN_ERR,
3597 				 "cluster size (%d) smaller than "
3598 				 "block size (%d)", clustersize, blocksize);
3599 			goto failed_mount;
3600 		}
3601 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3602 			le32_to_cpu(es->s_log_block_size);
3603 		sbi->s_clusters_per_group =
3604 			le32_to_cpu(es->s_clusters_per_group);
3605 		if (sbi->s_clusters_per_group > blocksize * 8) {
3606 			ext4_msg(sb, KERN_ERR,
3607 				 "#clusters per group too big: %lu",
3608 				 sbi->s_clusters_per_group);
3609 			goto failed_mount;
3610 		}
3611 		if (sbi->s_blocks_per_group !=
3612 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3613 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3614 				 "clusters per group (%lu) inconsistent",
3615 				 sbi->s_blocks_per_group,
3616 				 sbi->s_clusters_per_group);
3617 			goto failed_mount;
3618 		}
3619 	} else {
3620 		if (clustersize != blocksize) {
3621 			ext4_warning(sb, "fragment/cluster size (%d) != "
3622 				     "block size (%d)", clustersize,
3623 				     blocksize);
3624 			clustersize = blocksize;
3625 		}
3626 		if (sbi->s_blocks_per_group > blocksize * 8) {
3627 			ext4_msg(sb, KERN_ERR,
3628 				 "#blocks per group too big: %lu",
3629 				 sbi->s_blocks_per_group);
3630 			goto failed_mount;
3631 		}
3632 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3633 		sbi->s_cluster_bits = 0;
3634 	}
3635 	sbi->s_cluster_ratio = clustersize / blocksize;
3636 
3637 	if (sbi->s_inodes_per_group > blocksize * 8) {
3638 		ext4_msg(sb, KERN_ERR,
3639 		       "#inodes per group too big: %lu",
3640 		       sbi->s_inodes_per_group);
3641 		goto failed_mount;
3642 	}
3643 
3644 	/*
3645 	 * Test whether we have more sectors than will fit in sector_t,
3646 	 * and whether the max offset is addressable by the page cache.
3647 	 */
3648 	err = generic_check_addressable(sb->s_blocksize_bits,
3649 					ext4_blocks_count(es));
3650 	if (err) {
3651 		ext4_msg(sb, KERN_ERR, "filesystem"
3652 			 " too large to mount safely on this system");
3653 		if (sizeof(sector_t) < 8)
3654 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3655 		goto failed_mount;
3656 	}
3657 
3658 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3659 		goto cantfind_ext4;
3660 
3661 	/* check blocks count against device size */
3662 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3663 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3664 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3665 		       "exceeds size of device (%llu blocks)",
3666 		       ext4_blocks_count(es), blocks_count);
3667 		goto failed_mount;
3668 	}
3669 
3670 	/*
3671 	 * It makes no sense for the first data block to be beyond the end
3672 	 * of the filesystem.
3673 	 */
3674 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3675 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3676 			 "block %u is beyond end of filesystem (%llu)",
3677 			 le32_to_cpu(es->s_first_data_block),
3678 			 ext4_blocks_count(es));
3679 		goto failed_mount;
3680 	}
3681 	blocks_count = (ext4_blocks_count(es) -
3682 			le32_to_cpu(es->s_first_data_block) +
3683 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3684 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3685 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3686 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3687 		       "(block count %llu, first data block %u, "
3688 		       "blocks per group %lu)", sbi->s_groups_count,
3689 		       ext4_blocks_count(es),
3690 		       le32_to_cpu(es->s_first_data_block),
3691 		       EXT4_BLOCKS_PER_GROUP(sb));
3692 		goto failed_mount;
3693 	}
3694 	sbi->s_groups_count = blocks_count;
3695 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3696 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3697 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3698 		   EXT4_DESC_PER_BLOCK(sb);
3699 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3700 					  sizeof(struct buffer_head *),
3701 					  GFP_KERNEL);
3702 	if (sbi->s_group_desc == NULL) {
3703 		ext4_msg(sb, KERN_ERR, "not enough memory");
3704 		ret = -ENOMEM;
3705 		goto failed_mount;
3706 	}
3707 
3708 	if (ext4_proc_root)
3709 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3710 
3711 	if (sbi->s_proc)
3712 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3713 				 &ext4_seq_options_fops, sb);
3714 
3715 	bgl_lock_init(sbi->s_blockgroup_lock);
3716 
3717 	for (i = 0; i < db_count; i++) {
3718 		block = descriptor_loc(sb, logical_sb_block, i);
3719 		sbi->s_group_desc[i] = sb_bread(sb, block);
3720 		if (!sbi->s_group_desc[i]) {
3721 			ext4_msg(sb, KERN_ERR,
3722 			       "can't read group descriptor %d", i);
3723 			db_count = i;
3724 			goto failed_mount2;
3725 		}
3726 	}
3727 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3728 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3729 		goto failed_mount2;
3730 	}
3731 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3732 		if (!ext4_fill_flex_info(sb)) {
3733 			ext4_msg(sb, KERN_ERR,
3734 			       "unable to initialize "
3735 			       "flex_bg meta info!");
3736 			goto failed_mount2;
3737 		}
3738 
3739 	sbi->s_gdb_count = db_count;
3740 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3741 	spin_lock_init(&sbi->s_next_gen_lock);
3742 
3743 	init_timer(&sbi->s_err_report);
3744 	sbi->s_err_report.function = print_daily_error_info;
3745 	sbi->s_err_report.data = (unsigned long) sb;
3746 
3747 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3748 			ext4_count_free_clusters(sb));
3749 	if (!err) {
3750 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3751 				ext4_count_free_inodes(sb));
3752 	}
3753 	if (!err) {
3754 		err = percpu_counter_init(&sbi->s_dirs_counter,
3755 				ext4_count_dirs(sb));
3756 	}
3757 	if (!err) {
3758 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3759 	}
3760 	if (err) {
3761 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3762 		goto failed_mount3;
3763 	}
3764 
3765 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3766 	sbi->s_max_writeback_mb_bump = 128;
3767 	sbi->s_extent_max_zeroout_kb = 32;
3768 
3769 	/*
3770 	 * set up enough so that it can read an inode
3771 	 */
3772 	if (!test_opt(sb, NOLOAD) &&
3773 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3774 		sb->s_op = &ext4_sops;
3775 	else
3776 		sb->s_op = &ext4_nojournal_sops;
3777 	sb->s_export_op = &ext4_export_ops;
3778 	sb->s_xattr = ext4_xattr_handlers;
3779 #ifdef CONFIG_QUOTA
3780 	sb->s_qcop = &ext4_qctl_operations;
3781 	sb->dq_op = &ext4_quota_operations;
3782 
3783 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
3784 		/* Use qctl operations for hidden quota files. */
3785 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3786 	}
3787 #endif
3788 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3789 
3790 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3791 	mutex_init(&sbi->s_orphan_lock);
3792 
3793 	sb->s_root = NULL;
3794 
3795 	needs_recovery = (es->s_last_orphan != 0 ||
3796 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3797 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3798 
3799 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3800 	    !(sb->s_flags & MS_RDONLY))
3801 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3802 			goto failed_mount3;
3803 
3804 	/*
3805 	 * The first inode we look at is the journal inode.  Don't try
3806 	 * root first: it may be modified in the journal!
3807 	 */
3808 	if (!test_opt(sb, NOLOAD) &&
3809 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3810 		if (ext4_load_journal(sb, es, journal_devnum))
3811 			goto failed_mount3;
3812 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3813 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3814 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3815 		       "suppressed and not mounted read-only");
3816 		goto failed_mount_wq;
3817 	} else {
3818 		clear_opt(sb, DATA_FLAGS);
3819 		sbi->s_journal = NULL;
3820 		needs_recovery = 0;
3821 		goto no_journal;
3822 	}
3823 
3824 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3825 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3826 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3827 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3828 		goto failed_mount_wq;
3829 	}
3830 
3831 	if (!set_journal_csum_feature_set(sb)) {
3832 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3833 			 "feature set");
3834 		goto failed_mount_wq;
3835 	}
3836 
3837 	/* We have now updated the journal if required, so we can
3838 	 * validate the data journaling mode. */
3839 	switch (test_opt(sb, DATA_FLAGS)) {
3840 	case 0:
3841 		/* No mode set, assume a default based on the journal
3842 		 * capabilities: ORDERED_DATA if the journal can
3843 		 * cope, else JOURNAL_DATA
3844 		 */
3845 		if (jbd2_journal_check_available_features
3846 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3847 			set_opt(sb, ORDERED_DATA);
3848 		else
3849 			set_opt(sb, JOURNAL_DATA);
3850 		break;
3851 
3852 	case EXT4_MOUNT_ORDERED_DATA:
3853 	case EXT4_MOUNT_WRITEBACK_DATA:
3854 		if (!jbd2_journal_check_available_features
3855 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3856 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3857 			       "requested data journaling mode");
3858 			goto failed_mount_wq;
3859 		}
3860 	default:
3861 		break;
3862 	}
3863 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3864 
3865 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3866 
3867 	/*
3868 	 * The journal may have updated the bg summary counts, so we
3869 	 * need to update the global counters.
3870 	 */
3871 	percpu_counter_set(&sbi->s_freeclusters_counter,
3872 			   ext4_count_free_clusters(sb));
3873 	percpu_counter_set(&sbi->s_freeinodes_counter,
3874 			   ext4_count_free_inodes(sb));
3875 	percpu_counter_set(&sbi->s_dirs_counter,
3876 			   ext4_count_dirs(sb));
3877 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3878 
3879 no_journal:
3880 	/*
3881 	 * Get the # of file system overhead blocks from the
3882 	 * superblock if present.
3883 	 */
3884 	if (es->s_overhead_clusters)
3885 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3886 	else {
3887 		err = ext4_calculate_overhead(sb);
3888 		if (err)
3889 			goto failed_mount_wq;
3890 	}
3891 
3892 	/*
3893 	 * The maximum number of concurrent works can be high and
3894 	 * concurrency isn't really necessary.  Limit it to 1.
3895 	 */
3896 	EXT4_SB(sb)->dio_unwritten_wq =
3897 		alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3898 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3899 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3900 		ret = -ENOMEM;
3901 		goto failed_mount_wq;
3902 	}
3903 
3904 	/*
3905 	 * The jbd2_journal_load will have done any necessary log recovery,
3906 	 * so we can safely mount the rest of the filesystem now.
3907 	 */
3908 
3909 	root = ext4_iget(sb, EXT4_ROOT_INO);
3910 	if (IS_ERR(root)) {
3911 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3912 		ret = PTR_ERR(root);
3913 		root = NULL;
3914 		goto failed_mount4;
3915 	}
3916 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3917 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3918 		iput(root);
3919 		goto failed_mount4;
3920 	}
3921 	sb->s_root = d_make_root(root);
3922 	if (!sb->s_root) {
3923 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3924 		ret = -ENOMEM;
3925 		goto failed_mount4;
3926 	}
3927 
3928 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3929 		sb->s_flags |= MS_RDONLY;
3930 
3931 	/* determine the minimum size of new large inodes, if present */
3932 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3933 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3934 						     EXT4_GOOD_OLD_INODE_SIZE;
3935 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3936 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3937 			if (sbi->s_want_extra_isize <
3938 			    le16_to_cpu(es->s_want_extra_isize))
3939 				sbi->s_want_extra_isize =
3940 					le16_to_cpu(es->s_want_extra_isize);
3941 			if (sbi->s_want_extra_isize <
3942 			    le16_to_cpu(es->s_min_extra_isize))
3943 				sbi->s_want_extra_isize =
3944 					le16_to_cpu(es->s_min_extra_isize);
3945 		}
3946 	}
3947 	/* Check if enough inode space is available */
3948 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3949 							sbi->s_inode_size) {
3950 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3951 						       EXT4_GOOD_OLD_INODE_SIZE;
3952 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3953 			 "available");
3954 	}
3955 
3956 	err = ext4_setup_system_zone(sb);
3957 	if (err) {
3958 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3959 			 "zone (%d)", err);
3960 		goto failed_mount4a;
3961 	}
3962 
3963 	ext4_ext_init(sb);
3964 	err = ext4_mb_init(sb);
3965 	if (err) {
3966 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3967 			 err);
3968 		goto failed_mount5;
3969 	}
3970 
3971 	err = ext4_register_li_request(sb, first_not_zeroed);
3972 	if (err)
3973 		goto failed_mount6;
3974 
3975 	sbi->s_kobj.kset = ext4_kset;
3976 	init_completion(&sbi->s_kobj_unregister);
3977 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3978 				   "%s", sb->s_id);
3979 	if (err)
3980 		goto failed_mount7;
3981 
3982 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3983 	ext4_orphan_cleanup(sb, es);
3984 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3985 	if (needs_recovery) {
3986 		ext4_msg(sb, KERN_INFO, "recovery complete");
3987 		ext4_mark_recovery_complete(sb, es);
3988 	}
3989 	if (EXT4_SB(sb)->s_journal) {
3990 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3991 			descr = " journalled data mode";
3992 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3993 			descr = " ordered data mode";
3994 		else
3995 			descr = " writeback data mode";
3996 	} else
3997 		descr = "out journal";
3998 
3999 #ifdef CONFIG_QUOTA
4000 	/* Enable quota usage during mount. */
4001 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4002 	    !(sb->s_flags & MS_RDONLY)) {
4003 		err = ext4_enable_quotas(sb);
4004 		if (err)
4005 			goto failed_mount7;
4006 	}
4007 #endif  /* CONFIG_QUOTA */
4008 
4009 	if (test_opt(sb, DISCARD)) {
4010 		struct request_queue *q = bdev_get_queue(sb->s_bdev);
4011 		if (!blk_queue_discard(q))
4012 			ext4_msg(sb, KERN_WARNING,
4013 				 "mounting with \"discard\" option, but "
4014 				 "the device does not support discard");
4015 	}
4016 
4017 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4018 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4019 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4020 
4021 	if (es->s_error_count)
4022 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4023 
4024 	kfree(orig_data);
4025 	return 0;
4026 
4027 cantfind_ext4:
4028 	if (!silent)
4029 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4030 	goto failed_mount;
4031 
4032 failed_mount7:
4033 	ext4_unregister_li_request(sb);
4034 failed_mount6:
4035 	ext4_mb_release(sb);
4036 failed_mount5:
4037 	ext4_ext_release(sb);
4038 	ext4_release_system_zone(sb);
4039 failed_mount4a:
4040 	dput(sb->s_root);
4041 	sb->s_root = NULL;
4042 failed_mount4:
4043 	ext4_msg(sb, KERN_ERR, "mount failed");
4044 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4045 failed_mount_wq:
4046 	if (sbi->s_journal) {
4047 		jbd2_journal_destroy(sbi->s_journal);
4048 		sbi->s_journal = NULL;
4049 	}
4050 failed_mount3:
4051 	del_timer(&sbi->s_err_report);
4052 	if (sbi->s_flex_groups)
4053 		ext4_kvfree(sbi->s_flex_groups);
4054 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4055 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4056 	percpu_counter_destroy(&sbi->s_dirs_counter);
4057 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4058 	if (sbi->s_mmp_tsk)
4059 		kthread_stop(sbi->s_mmp_tsk);
4060 failed_mount2:
4061 	for (i = 0; i < db_count; i++)
4062 		brelse(sbi->s_group_desc[i]);
4063 	ext4_kvfree(sbi->s_group_desc);
4064 failed_mount:
4065 	if (sbi->s_chksum_driver)
4066 		crypto_free_shash(sbi->s_chksum_driver);
4067 	if (sbi->s_proc) {
4068 		remove_proc_entry("options", sbi->s_proc);
4069 		remove_proc_entry(sb->s_id, ext4_proc_root);
4070 	}
4071 #ifdef CONFIG_QUOTA
4072 	for (i = 0; i < MAXQUOTAS; i++)
4073 		kfree(sbi->s_qf_names[i]);
4074 #endif
4075 	ext4_blkdev_remove(sbi);
4076 	brelse(bh);
4077 out_fail:
4078 	sb->s_fs_info = NULL;
4079 	kfree(sbi->s_blockgroup_lock);
4080 	kfree(sbi);
4081 out_free_orig:
4082 	kfree(orig_data);
4083 	return err ? err : ret;
4084 }
4085 
4086 /*
4087  * Setup any per-fs journal parameters now.  We'll do this both on
4088  * initial mount, once the journal has been initialised but before we've
4089  * done any recovery; and again on any subsequent remount.
4090  */
4091 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4092 {
4093 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4094 
4095 	journal->j_commit_interval = sbi->s_commit_interval;
4096 	journal->j_min_batch_time = sbi->s_min_batch_time;
4097 	journal->j_max_batch_time = sbi->s_max_batch_time;
4098 
4099 	write_lock(&journal->j_state_lock);
4100 	if (test_opt(sb, BARRIER))
4101 		journal->j_flags |= JBD2_BARRIER;
4102 	else
4103 		journal->j_flags &= ~JBD2_BARRIER;
4104 	if (test_opt(sb, DATA_ERR_ABORT))
4105 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4106 	else
4107 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4108 	write_unlock(&journal->j_state_lock);
4109 }
4110 
4111 static journal_t *ext4_get_journal(struct super_block *sb,
4112 				   unsigned int journal_inum)
4113 {
4114 	struct inode *journal_inode;
4115 	journal_t *journal;
4116 
4117 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4118 
4119 	/* First, test for the existence of a valid inode on disk.  Bad
4120 	 * things happen if we iget() an unused inode, as the subsequent
4121 	 * iput() will try to delete it. */
4122 
4123 	journal_inode = ext4_iget(sb, journal_inum);
4124 	if (IS_ERR(journal_inode)) {
4125 		ext4_msg(sb, KERN_ERR, "no journal found");
4126 		return NULL;
4127 	}
4128 	if (!journal_inode->i_nlink) {
4129 		make_bad_inode(journal_inode);
4130 		iput(journal_inode);
4131 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4132 		return NULL;
4133 	}
4134 
4135 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4136 		  journal_inode, journal_inode->i_size);
4137 	if (!S_ISREG(journal_inode->i_mode)) {
4138 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4139 		iput(journal_inode);
4140 		return NULL;
4141 	}
4142 
4143 	journal = jbd2_journal_init_inode(journal_inode);
4144 	if (!journal) {
4145 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4146 		iput(journal_inode);
4147 		return NULL;
4148 	}
4149 	journal->j_private = sb;
4150 	ext4_init_journal_params(sb, journal);
4151 	return journal;
4152 }
4153 
4154 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4155 				       dev_t j_dev)
4156 {
4157 	struct buffer_head *bh;
4158 	journal_t *journal;
4159 	ext4_fsblk_t start;
4160 	ext4_fsblk_t len;
4161 	int hblock, blocksize;
4162 	ext4_fsblk_t sb_block;
4163 	unsigned long offset;
4164 	struct ext4_super_block *es;
4165 	struct block_device *bdev;
4166 
4167 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4168 
4169 	bdev = ext4_blkdev_get(j_dev, sb);
4170 	if (bdev == NULL)
4171 		return NULL;
4172 
4173 	blocksize = sb->s_blocksize;
4174 	hblock = bdev_logical_block_size(bdev);
4175 	if (blocksize < hblock) {
4176 		ext4_msg(sb, KERN_ERR,
4177 			"blocksize too small for journal device");
4178 		goto out_bdev;
4179 	}
4180 
4181 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4182 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4183 	set_blocksize(bdev, blocksize);
4184 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4185 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4186 		       "external journal");
4187 		goto out_bdev;
4188 	}
4189 
4190 	es = (struct ext4_super_block *) (bh->b_data + offset);
4191 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4192 	    !(le32_to_cpu(es->s_feature_incompat) &
4193 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4194 		ext4_msg(sb, KERN_ERR, "external journal has "
4195 					"bad superblock");
4196 		brelse(bh);
4197 		goto out_bdev;
4198 	}
4199 
4200 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4201 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4202 		brelse(bh);
4203 		goto out_bdev;
4204 	}
4205 
4206 	len = ext4_blocks_count(es);
4207 	start = sb_block + 1;
4208 	brelse(bh);	/* we're done with the superblock */
4209 
4210 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4211 					start, len, blocksize);
4212 	if (!journal) {
4213 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4214 		goto out_bdev;
4215 	}
4216 	journal->j_private = sb;
4217 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
4218 	wait_on_buffer(journal->j_sb_buffer);
4219 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4220 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4221 		goto out_journal;
4222 	}
4223 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4224 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4225 					"user (unsupported) - %d",
4226 			be32_to_cpu(journal->j_superblock->s_nr_users));
4227 		goto out_journal;
4228 	}
4229 	EXT4_SB(sb)->journal_bdev = bdev;
4230 	ext4_init_journal_params(sb, journal);
4231 	return journal;
4232 
4233 out_journal:
4234 	jbd2_journal_destroy(journal);
4235 out_bdev:
4236 	ext4_blkdev_put(bdev);
4237 	return NULL;
4238 }
4239 
4240 static int ext4_load_journal(struct super_block *sb,
4241 			     struct ext4_super_block *es,
4242 			     unsigned long journal_devnum)
4243 {
4244 	journal_t *journal;
4245 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4246 	dev_t journal_dev;
4247 	int err = 0;
4248 	int really_read_only;
4249 
4250 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4251 
4252 	if (journal_devnum &&
4253 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4254 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4255 			"numbers have changed");
4256 		journal_dev = new_decode_dev(journal_devnum);
4257 	} else
4258 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4259 
4260 	really_read_only = bdev_read_only(sb->s_bdev);
4261 
4262 	/*
4263 	 * Are we loading a blank journal or performing recovery after a
4264 	 * crash?  For recovery, we need to check in advance whether we
4265 	 * can get read-write access to the device.
4266 	 */
4267 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4268 		if (sb->s_flags & MS_RDONLY) {
4269 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4270 					"required on readonly filesystem");
4271 			if (really_read_only) {
4272 				ext4_msg(sb, KERN_ERR, "write access "
4273 					"unavailable, cannot proceed");
4274 				return -EROFS;
4275 			}
4276 			ext4_msg(sb, KERN_INFO, "write access will "
4277 			       "be enabled during recovery");
4278 		}
4279 	}
4280 
4281 	if (journal_inum && journal_dev) {
4282 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4283 		       "and inode journals!");
4284 		return -EINVAL;
4285 	}
4286 
4287 	if (journal_inum) {
4288 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4289 			return -EINVAL;
4290 	} else {
4291 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4292 			return -EINVAL;
4293 	}
4294 
4295 	if (!(journal->j_flags & JBD2_BARRIER))
4296 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4297 
4298 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4299 		err = jbd2_journal_wipe(journal, !really_read_only);
4300 	if (!err) {
4301 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4302 		if (save)
4303 			memcpy(save, ((char *) es) +
4304 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4305 		err = jbd2_journal_load(journal);
4306 		if (save)
4307 			memcpy(((char *) es) + EXT4_S_ERR_START,
4308 			       save, EXT4_S_ERR_LEN);
4309 		kfree(save);
4310 	}
4311 
4312 	if (err) {
4313 		ext4_msg(sb, KERN_ERR, "error loading journal");
4314 		jbd2_journal_destroy(journal);
4315 		return err;
4316 	}
4317 
4318 	EXT4_SB(sb)->s_journal = journal;
4319 	ext4_clear_journal_err(sb, es);
4320 
4321 	if (!really_read_only && journal_devnum &&
4322 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4323 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4324 
4325 		/* Make sure we flush the recovery flag to disk. */
4326 		ext4_commit_super(sb, 1);
4327 	}
4328 
4329 	return 0;
4330 }
4331 
4332 static int ext4_commit_super(struct super_block *sb, int sync)
4333 {
4334 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4335 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4336 	int error = 0;
4337 
4338 	if (!sbh || block_device_ejected(sb))
4339 		return error;
4340 	if (buffer_write_io_error(sbh)) {
4341 		/*
4342 		 * Oh, dear.  A previous attempt to write the
4343 		 * superblock failed.  This could happen because the
4344 		 * USB device was yanked out.  Or it could happen to
4345 		 * be a transient write error and maybe the block will
4346 		 * be remapped.  Nothing we can do but to retry the
4347 		 * write and hope for the best.
4348 		 */
4349 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4350 		       "superblock detected");
4351 		clear_buffer_write_io_error(sbh);
4352 		set_buffer_uptodate(sbh);
4353 	}
4354 	/*
4355 	 * If the file system is mounted read-only, don't update the
4356 	 * superblock write time.  This avoids updating the superblock
4357 	 * write time when we are mounting the root file system
4358 	 * read/only but we need to replay the journal; at that point,
4359 	 * for people who are east of GMT and who make their clock
4360 	 * tick in localtime for Windows bug-for-bug compatibility,
4361 	 * the clock is set in the future, and this will cause e2fsck
4362 	 * to complain and force a full file system check.
4363 	 */
4364 	if (!(sb->s_flags & MS_RDONLY))
4365 		es->s_wtime = cpu_to_le32(get_seconds());
4366 	if (sb->s_bdev->bd_part)
4367 		es->s_kbytes_written =
4368 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4369 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4370 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4371 	else
4372 		es->s_kbytes_written =
4373 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4374 	ext4_free_blocks_count_set(es,
4375 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4376 				&EXT4_SB(sb)->s_freeclusters_counter)));
4377 	es->s_free_inodes_count =
4378 		cpu_to_le32(percpu_counter_sum_positive(
4379 				&EXT4_SB(sb)->s_freeinodes_counter));
4380 	BUFFER_TRACE(sbh, "marking dirty");
4381 	ext4_superblock_csum_set(sb);
4382 	mark_buffer_dirty(sbh);
4383 	if (sync) {
4384 		error = sync_dirty_buffer(sbh);
4385 		if (error)
4386 			return error;
4387 
4388 		error = buffer_write_io_error(sbh);
4389 		if (error) {
4390 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4391 			       "superblock");
4392 			clear_buffer_write_io_error(sbh);
4393 			set_buffer_uptodate(sbh);
4394 		}
4395 	}
4396 	return error;
4397 }
4398 
4399 /*
4400  * Have we just finished recovery?  If so, and if we are mounting (or
4401  * remounting) the filesystem readonly, then we will end up with a
4402  * consistent fs on disk.  Record that fact.
4403  */
4404 static void ext4_mark_recovery_complete(struct super_block *sb,
4405 					struct ext4_super_block *es)
4406 {
4407 	journal_t *journal = EXT4_SB(sb)->s_journal;
4408 
4409 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4410 		BUG_ON(journal != NULL);
4411 		return;
4412 	}
4413 	jbd2_journal_lock_updates(journal);
4414 	if (jbd2_journal_flush(journal) < 0)
4415 		goto out;
4416 
4417 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4418 	    sb->s_flags & MS_RDONLY) {
4419 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4420 		ext4_commit_super(sb, 1);
4421 	}
4422 
4423 out:
4424 	jbd2_journal_unlock_updates(journal);
4425 }
4426 
4427 /*
4428  * If we are mounting (or read-write remounting) a filesystem whose journal
4429  * has recorded an error from a previous lifetime, move that error to the
4430  * main filesystem now.
4431  */
4432 static void ext4_clear_journal_err(struct super_block *sb,
4433 				   struct ext4_super_block *es)
4434 {
4435 	journal_t *journal;
4436 	int j_errno;
4437 	const char *errstr;
4438 
4439 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4440 
4441 	journal = EXT4_SB(sb)->s_journal;
4442 
4443 	/*
4444 	 * Now check for any error status which may have been recorded in the
4445 	 * journal by a prior ext4_error() or ext4_abort()
4446 	 */
4447 
4448 	j_errno = jbd2_journal_errno(journal);
4449 	if (j_errno) {
4450 		char nbuf[16];
4451 
4452 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4453 		ext4_warning(sb, "Filesystem error recorded "
4454 			     "from previous mount: %s", errstr);
4455 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4456 
4457 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4458 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4459 		ext4_commit_super(sb, 1);
4460 
4461 		jbd2_journal_clear_err(journal);
4462 		jbd2_journal_update_sb_errno(journal);
4463 	}
4464 }
4465 
4466 /*
4467  * Force the running and committing transactions to commit,
4468  * and wait on the commit.
4469  */
4470 int ext4_force_commit(struct super_block *sb)
4471 {
4472 	journal_t *journal;
4473 	int ret = 0;
4474 
4475 	if (sb->s_flags & MS_RDONLY)
4476 		return 0;
4477 
4478 	journal = EXT4_SB(sb)->s_journal;
4479 	if (journal)
4480 		ret = ext4_journal_force_commit(journal);
4481 
4482 	return ret;
4483 }
4484 
4485 static int ext4_sync_fs(struct super_block *sb, int wait)
4486 {
4487 	int ret = 0;
4488 	tid_t target;
4489 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4490 
4491 	trace_ext4_sync_fs(sb, wait);
4492 	flush_workqueue(sbi->dio_unwritten_wq);
4493 	/*
4494 	 * Writeback quota in non-journalled quota case - journalled quota has
4495 	 * no dirty dquots
4496 	 */
4497 	dquot_writeback_dquots(sb, -1);
4498 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4499 		if (wait)
4500 			jbd2_log_wait_commit(sbi->s_journal, target);
4501 	}
4502 	return ret;
4503 }
4504 
4505 /*
4506  * LVM calls this function before a (read-only) snapshot is created.  This
4507  * gives us a chance to flush the journal completely and mark the fs clean.
4508  *
4509  * Note that only this function cannot bring a filesystem to be in a clean
4510  * state independently. It relies on upper layer to stop all data & metadata
4511  * modifications.
4512  */
4513 static int ext4_freeze(struct super_block *sb)
4514 {
4515 	int error = 0;
4516 	journal_t *journal;
4517 
4518 	if (sb->s_flags & MS_RDONLY)
4519 		return 0;
4520 
4521 	journal = EXT4_SB(sb)->s_journal;
4522 
4523 	/* Now we set up the journal barrier. */
4524 	jbd2_journal_lock_updates(journal);
4525 
4526 	/*
4527 	 * Don't clear the needs_recovery flag if we failed to flush
4528 	 * the journal.
4529 	 */
4530 	error = jbd2_journal_flush(journal);
4531 	if (error < 0)
4532 		goto out;
4533 
4534 	/* Journal blocked and flushed, clear needs_recovery flag. */
4535 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4536 	error = ext4_commit_super(sb, 1);
4537 out:
4538 	/* we rely on upper layer to stop further updates */
4539 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4540 	return error;
4541 }
4542 
4543 /*
4544  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4545  * flag here, even though the filesystem is not technically dirty yet.
4546  */
4547 static int ext4_unfreeze(struct super_block *sb)
4548 {
4549 	if (sb->s_flags & MS_RDONLY)
4550 		return 0;
4551 
4552 	/* Reset the needs_recovery flag before the fs is unlocked. */
4553 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4554 	ext4_commit_super(sb, 1);
4555 	return 0;
4556 }
4557 
4558 /*
4559  * Structure to save mount options for ext4_remount's benefit
4560  */
4561 struct ext4_mount_options {
4562 	unsigned long s_mount_opt;
4563 	unsigned long s_mount_opt2;
4564 	kuid_t s_resuid;
4565 	kgid_t s_resgid;
4566 	unsigned long s_commit_interval;
4567 	u32 s_min_batch_time, s_max_batch_time;
4568 #ifdef CONFIG_QUOTA
4569 	int s_jquota_fmt;
4570 	char *s_qf_names[MAXQUOTAS];
4571 #endif
4572 };
4573 
4574 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4575 {
4576 	struct ext4_super_block *es;
4577 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4578 	unsigned long old_sb_flags;
4579 	struct ext4_mount_options old_opts;
4580 	int enable_quota = 0;
4581 	ext4_group_t g;
4582 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4583 	int err = 0;
4584 #ifdef CONFIG_QUOTA
4585 	int i;
4586 #endif
4587 	char *orig_data = kstrdup(data, GFP_KERNEL);
4588 
4589 	/* Store the original options */
4590 	old_sb_flags = sb->s_flags;
4591 	old_opts.s_mount_opt = sbi->s_mount_opt;
4592 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4593 	old_opts.s_resuid = sbi->s_resuid;
4594 	old_opts.s_resgid = sbi->s_resgid;
4595 	old_opts.s_commit_interval = sbi->s_commit_interval;
4596 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4597 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4598 #ifdef CONFIG_QUOTA
4599 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4600 	for (i = 0; i < MAXQUOTAS; i++)
4601 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4602 #endif
4603 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4604 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4605 
4606 	/*
4607 	 * Allow the "check" option to be passed as a remount option.
4608 	 */
4609 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4610 		err = -EINVAL;
4611 		goto restore_opts;
4612 	}
4613 
4614 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4615 		ext4_abort(sb, "Abort forced by user");
4616 
4617 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4618 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4619 
4620 	es = sbi->s_es;
4621 
4622 	if (sbi->s_journal) {
4623 		ext4_init_journal_params(sb, sbi->s_journal);
4624 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4625 	}
4626 
4627 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4628 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4629 			err = -EROFS;
4630 			goto restore_opts;
4631 		}
4632 
4633 		if (*flags & MS_RDONLY) {
4634 			err = dquot_suspend(sb, -1);
4635 			if (err < 0)
4636 				goto restore_opts;
4637 
4638 			/*
4639 			 * First of all, the unconditional stuff we have to do
4640 			 * to disable replay of the journal when we next remount
4641 			 */
4642 			sb->s_flags |= MS_RDONLY;
4643 
4644 			/*
4645 			 * OK, test if we are remounting a valid rw partition
4646 			 * readonly, and if so set the rdonly flag and then
4647 			 * mark the partition as valid again.
4648 			 */
4649 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4650 			    (sbi->s_mount_state & EXT4_VALID_FS))
4651 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4652 
4653 			if (sbi->s_journal)
4654 				ext4_mark_recovery_complete(sb, es);
4655 		} else {
4656 			/* Make sure we can mount this feature set readwrite */
4657 			if (!ext4_feature_set_ok(sb, 0)) {
4658 				err = -EROFS;
4659 				goto restore_opts;
4660 			}
4661 			/*
4662 			 * Make sure the group descriptor checksums
4663 			 * are sane.  If they aren't, refuse to remount r/w.
4664 			 */
4665 			for (g = 0; g < sbi->s_groups_count; g++) {
4666 				struct ext4_group_desc *gdp =
4667 					ext4_get_group_desc(sb, g, NULL);
4668 
4669 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4670 					ext4_msg(sb, KERN_ERR,
4671 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4672 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4673 					       le16_to_cpu(gdp->bg_checksum));
4674 					err = -EINVAL;
4675 					goto restore_opts;
4676 				}
4677 			}
4678 
4679 			/*
4680 			 * If we have an unprocessed orphan list hanging
4681 			 * around from a previously readonly bdev mount,
4682 			 * require a full umount/remount for now.
4683 			 */
4684 			if (es->s_last_orphan) {
4685 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4686 				       "remount RDWR because of unprocessed "
4687 				       "orphan inode list.  Please "
4688 				       "umount/remount instead");
4689 				err = -EINVAL;
4690 				goto restore_opts;
4691 			}
4692 
4693 			/*
4694 			 * Mounting a RDONLY partition read-write, so reread
4695 			 * and store the current valid flag.  (It may have
4696 			 * been changed by e2fsck since we originally mounted
4697 			 * the partition.)
4698 			 */
4699 			if (sbi->s_journal)
4700 				ext4_clear_journal_err(sb, es);
4701 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4702 			if (!ext4_setup_super(sb, es, 0))
4703 				sb->s_flags &= ~MS_RDONLY;
4704 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4705 						     EXT4_FEATURE_INCOMPAT_MMP))
4706 				if (ext4_multi_mount_protect(sb,
4707 						le64_to_cpu(es->s_mmp_block))) {
4708 					err = -EROFS;
4709 					goto restore_opts;
4710 				}
4711 			enable_quota = 1;
4712 		}
4713 	}
4714 
4715 	/*
4716 	 * Reinitialize lazy itable initialization thread based on
4717 	 * current settings
4718 	 */
4719 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4720 		ext4_unregister_li_request(sb);
4721 	else {
4722 		ext4_group_t first_not_zeroed;
4723 		first_not_zeroed = ext4_has_uninit_itable(sb);
4724 		ext4_register_li_request(sb, first_not_zeroed);
4725 	}
4726 
4727 	ext4_setup_system_zone(sb);
4728 	if (sbi->s_journal == NULL)
4729 		ext4_commit_super(sb, 1);
4730 
4731 #ifdef CONFIG_QUOTA
4732 	/* Release old quota file names */
4733 	for (i = 0; i < MAXQUOTAS; i++)
4734 		if (old_opts.s_qf_names[i] &&
4735 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4736 			kfree(old_opts.s_qf_names[i]);
4737 	if (enable_quota) {
4738 		if (sb_any_quota_suspended(sb))
4739 			dquot_resume(sb, -1);
4740 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4741 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4742 			err = ext4_enable_quotas(sb);
4743 			if (err)
4744 				goto restore_opts;
4745 		}
4746 	}
4747 #endif
4748 
4749 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4750 	kfree(orig_data);
4751 	return 0;
4752 
4753 restore_opts:
4754 	sb->s_flags = old_sb_flags;
4755 	sbi->s_mount_opt = old_opts.s_mount_opt;
4756 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4757 	sbi->s_resuid = old_opts.s_resuid;
4758 	sbi->s_resgid = old_opts.s_resgid;
4759 	sbi->s_commit_interval = old_opts.s_commit_interval;
4760 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4761 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4762 #ifdef CONFIG_QUOTA
4763 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4764 	for (i = 0; i < MAXQUOTAS; i++) {
4765 		if (sbi->s_qf_names[i] &&
4766 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4767 			kfree(sbi->s_qf_names[i]);
4768 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4769 	}
4770 #endif
4771 	kfree(orig_data);
4772 	return err;
4773 }
4774 
4775 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4776 {
4777 	struct super_block *sb = dentry->d_sb;
4778 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4779 	struct ext4_super_block *es = sbi->s_es;
4780 	ext4_fsblk_t overhead = 0;
4781 	u64 fsid;
4782 	s64 bfree;
4783 
4784 	if (!test_opt(sb, MINIX_DF))
4785 		overhead = sbi->s_overhead;
4786 
4787 	buf->f_type = EXT4_SUPER_MAGIC;
4788 	buf->f_bsize = sb->s_blocksize;
4789 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead);
4790 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4791 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4792 	/* prevent underflow in case that few free space is available */
4793 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4794 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4795 	if (buf->f_bfree < ext4_r_blocks_count(es))
4796 		buf->f_bavail = 0;
4797 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4798 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4799 	buf->f_namelen = EXT4_NAME_LEN;
4800 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4801 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4802 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4803 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4804 
4805 	return 0;
4806 }
4807 
4808 /* Helper function for writing quotas on sync - we need to start transaction
4809  * before quota file is locked for write. Otherwise the are possible deadlocks:
4810  * Process 1                         Process 2
4811  * ext4_create()                     quota_sync()
4812  *   jbd2_journal_start()                  write_dquot()
4813  *   dquot_initialize()                         down(dqio_mutex)
4814  *     down(dqio_mutex)                    jbd2_journal_start()
4815  *
4816  */
4817 
4818 #ifdef CONFIG_QUOTA
4819 
4820 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4821 {
4822 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4823 }
4824 
4825 static int ext4_write_dquot(struct dquot *dquot)
4826 {
4827 	int ret, err;
4828 	handle_t *handle;
4829 	struct inode *inode;
4830 
4831 	inode = dquot_to_inode(dquot);
4832 	handle = ext4_journal_start(inode,
4833 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4834 	if (IS_ERR(handle))
4835 		return PTR_ERR(handle);
4836 	ret = dquot_commit(dquot);
4837 	err = ext4_journal_stop(handle);
4838 	if (!ret)
4839 		ret = err;
4840 	return ret;
4841 }
4842 
4843 static int ext4_acquire_dquot(struct dquot *dquot)
4844 {
4845 	int ret, err;
4846 	handle_t *handle;
4847 
4848 	handle = ext4_journal_start(dquot_to_inode(dquot),
4849 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4850 	if (IS_ERR(handle))
4851 		return PTR_ERR(handle);
4852 	ret = dquot_acquire(dquot);
4853 	err = ext4_journal_stop(handle);
4854 	if (!ret)
4855 		ret = err;
4856 	return ret;
4857 }
4858 
4859 static int ext4_release_dquot(struct dquot *dquot)
4860 {
4861 	int ret, err;
4862 	handle_t *handle;
4863 
4864 	handle = ext4_journal_start(dquot_to_inode(dquot),
4865 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4866 	if (IS_ERR(handle)) {
4867 		/* Release dquot anyway to avoid endless cycle in dqput() */
4868 		dquot_release(dquot);
4869 		return PTR_ERR(handle);
4870 	}
4871 	ret = dquot_release(dquot);
4872 	err = ext4_journal_stop(handle);
4873 	if (!ret)
4874 		ret = err;
4875 	return ret;
4876 }
4877 
4878 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4879 {
4880 	/* Are we journaling quotas? */
4881 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4882 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4883 		dquot_mark_dquot_dirty(dquot);
4884 		return ext4_write_dquot(dquot);
4885 	} else {
4886 		return dquot_mark_dquot_dirty(dquot);
4887 	}
4888 }
4889 
4890 static int ext4_write_info(struct super_block *sb, int type)
4891 {
4892 	int ret, err;
4893 	handle_t *handle;
4894 
4895 	/* Data block + inode block */
4896 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
4897 	if (IS_ERR(handle))
4898 		return PTR_ERR(handle);
4899 	ret = dquot_commit_info(sb, type);
4900 	err = ext4_journal_stop(handle);
4901 	if (!ret)
4902 		ret = err;
4903 	return ret;
4904 }
4905 
4906 /*
4907  * Turn on quotas during mount time - we need to find
4908  * the quota file and such...
4909  */
4910 static int ext4_quota_on_mount(struct super_block *sb, int type)
4911 {
4912 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4913 					EXT4_SB(sb)->s_jquota_fmt, type);
4914 }
4915 
4916 /*
4917  * Standard function to be called on quota_on
4918  */
4919 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4920 			 struct path *path)
4921 {
4922 	int err;
4923 
4924 	if (!test_opt(sb, QUOTA))
4925 		return -EINVAL;
4926 
4927 	/* Quotafile not on the same filesystem? */
4928 	if (path->dentry->d_sb != sb)
4929 		return -EXDEV;
4930 	/* Journaling quota? */
4931 	if (EXT4_SB(sb)->s_qf_names[type]) {
4932 		/* Quotafile not in fs root? */
4933 		if (path->dentry->d_parent != sb->s_root)
4934 			ext4_msg(sb, KERN_WARNING,
4935 				"Quota file not on filesystem root. "
4936 				"Journaled quota will not work");
4937 	}
4938 
4939 	/*
4940 	 * When we journal data on quota file, we have to flush journal to see
4941 	 * all updates to the file when we bypass pagecache...
4942 	 */
4943 	if (EXT4_SB(sb)->s_journal &&
4944 	    ext4_should_journal_data(path->dentry->d_inode)) {
4945 		/*
4946 		 * We don't need to lock updates but journal_flush() could
4947 		 * otherwise be livelocked...
4948 		 */
4949 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4950 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4951 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4952 		if (err)
4953 			return err;
4954 	}
4955 
4956 	return dquot_quota_on(sb, type, format_id, path);
4957 }
4958 
4959 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4960 			     unsigned int flags)
4961 {
4962 	int err;
4963 	struct inode *qf_inode;
4964 	unsigned long qf_inums[MAXQUOTAS] = {
4965 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4966 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4967 	};
4968 
4969 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4970 
4971 	if (!qf_inums[type])
4972 		return -EPERM;
4973 
4974 	qf_inode = ext4_iget(sb, qf_inums[type]);
4975 	if (IS_ERR(qf_inode)) {
4976 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4977 		return PTR_ERR(qf_inode);
4978 	}
4979 
4980 	err = dquot_enable(qf_inode, type, format_id, flags);
4981 	iput(qf_inode);
4982 
4983 	return err;
4984 }
4985 
4986 /* Enable usage tracking for all quota types. */
4987 static int ext4_enable_quotas(struct super_block *sb)
4988 {
4989 	int type, err = 0;
4990 	unsigned long qf_inums[MAXQUOTAS] = {
4991 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4992 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4993 	};
4994 
4995 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
4996 	for (type = 0; type < MAXQUOTAS; type++) {
4997 		if (qf_inums[type]) {
4998 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
4999 						DQUOT_USAGE_ENABLED);
5000 			if (err) {
5001 				ext4_warning(sb,
5002 					"Failed to enable quota (type=%d) "
5003 					"tracking. Please run e2fsck to fix.",
5004 					type);
5005 				return err;
5006 			}
5007 		}
5008 	}
5009 	return 0;
5010 }
5011 
5012 /*
5013  * quota_on function that is used when QUOTA feature is set.
5014  */
5015 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5016 				 int format_id)
5017 {
5018 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5019 		return -EINVAL;
5020 
5021 	/*
5022 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
5023 	 */
5024 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5025 }
5026 
5027 static int ext4_quota_off(struct super_block *sb, int type)
5028 {
5029 	struct inode *inode = sb_dqopt(sb)->files[type];
5030 	handle_t *handle;
5031 
5032 	/* Force all delayed allocation blocks to be allocated.
5033 	 * Caller already holds s_umount sem */
5034 	if (test_opt(sb, DELALLOC))
5035 		sync_filesystem(sb);
5036 
5037 	if (!inode)
5038 		goto out;
5039 
5040 	/* Update modification times of quota files when userspace can
5041 	 * start looking at them */
5042 	handle = ext4_journal_start(inode, 1);
5043 	if (IS_ERR(handle))
5044 		goto out;
5045 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5046 	ext4_mark_inode_dirty(handle, inode);
5047 	ext4_journal_stop(handle);
5048 
5049 out:
5050 	return dquot_quota_off(sb, type);
5051 }
5052 
5053 /*
5054  * quota_off function that is used when QUOTA feature is set.
5055  */
5056 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5057 {
5058 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5059 		return -EINVAL;
5060 
5061 	/* Disable only the limits. */
5062 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5063 }
5064 
5065 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5066  * acquiring the locks... As quota files are never truncated and quota code
5067  * itself serializes the operations (and no one else should touch the files)
5068  * we don't have to be afraid of races */
5069 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5070 			       size_t len, loff_t off)
5071 {
5072 	struct inode *inode = sb_dqopt(sb)->files[type];
5073 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5074 	int err = 0;
5075 	int offset = off & (sb->s_blocksize - 1);
5076 	int tocopy;
5077 	size_t toread;
5078 	struct buffer_head *bh;
5079 	loff_t i_size = i_size_read(inode);
5080 
5081 	if (off > i_size)
5082 		return 0;
5083 	if (off+len > i_size)
5084 		len = i_size-off;
5085 	toread = len;
5086 	while (toread > 0) {
5087 		tocopy = sb->s_blocksize - offset < toread ?
5088 				sb->s_blocksize - offset : toread;
5089 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5090 		if (err)
5091 			return err;
5092 		if (!bh)	/* A hole? */
5093 			memset(data, 0, tocopy);
5094 		else
5095 			memcpy(data, bh->b_data+offset, tocopy);
5096 		brelse(bh);
5097 		offset = 0;
5098 		toread -= tocopy;
5099 		data += tocopy;
5100 		blk++;
5101 	}
5102 	return len;
5103 }
5104 
5105 /* Write to quotafile (we know the transaction is already started and has
5106  * enough credits) */
5107 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5108 				const char *data, size_t len, loff_t off)
5109 {
5110 	struct inode *inode = sb_dqopt(sb)->files[type];
5111 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5112 	int err = 0;
5113 	int offset = off & (sb->s_blocksize - 1);
5114 	struct buffer_head *bh;
5115 	handle_t *handle = journal_current_handle();
5116 
5117 	if (EXT4_SB(sb)->s_journal && !handle) {
5118 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5119 			" cancelled because transaction is not started",
5120 			(unsigned long long)off, (unsigned long long)len);
5121 		return -EIO;
5122 	}
5123 	/*
5124 	 * Since we account only one data block in transaction credits,
5125 	 * then it is impossible to cross a block boundary.
5126 	 */
5127 	if (sb->s_blocksize - offset < len) {
5128 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5129 			" cancelled because not block aligned",
5130 			(unsigned long long)off, (unsigned long long)len);
5131 		return -EIO;
5132 	}
5133 
5134 	bh = ext4_bread(handle, inode, blk, 1, &err);
5135 	if (!bh)
5136 		goto out;
5137 	err = ext4_journal_get_write_access(handle, bh);
5138 	if (err) {
5139 		brelse(bh);
5140 		goto out;
5141 	}
5142 	lock_buffer(bh);
5143 	memcpy(bh->b_data+offset, data, len);
5144 	flush_dcache_page(bh->b_page);
5145 	unlock_buffer(bh);
5146 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5147 	brelse(bh);
5148 out:
5149 	if (err)
5150 		return err;
5151 	if (inode->i_size < off + len) {
5152 		i_size_write(inode, off + len);
5153 		EXT4_I(inode)->i_disksize = inode->i_size;
5154 		ext4_mark_inode_dirty(handle, inode);
5155 	}
5156 	return len;
5157 }
5158 
5159 #endif
5160 
5161 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5162 		       const char *dev_name, void *data)
5163 {
5164 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5165 }
5166 
5167 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5168 static inline void register_as_ext2(void)
5169 {
5170 	int err = register_filesystem(&ext2_fs_type);
5171 	if (err)
5172 		printk(KERN_WARNING
5173 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5174 }
5175 
5176 static inline void unregister_as_ext2(void)
5177 {
5178 	unregister_filesystem(&ext2_fs_type);
5179 }
5180 
5181 static inline int ext2_feature_set_ok(struct super_block *sb)
5182 {
5183 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5184 		return 0;
5185 	if (sb->s_flags & MS_RDONLY)
5186 		return 1;
5187 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5188 		return 0;
5189 	return 1;
5190 }
5191 MODULE_ALIAS("ext2");
5192 #else
5193 static inline void register_as_ext2(void) { }
5194 static inline void unregister_as_ext2(void) { }
5195 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5196 #endif
5197 
5198 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5199 static inline void register_as_ext3(void)
5200 {
5201 	int err = register_filesystem(&ext3_fs_type);
5202 	if (err)
5203 		printk(KERN_WARNING
5204 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5205 }
5206 
5207 static inline void unregister_as_ext3(void)
5208 {
5209 	unregister_filesystem(&ext3_fs_type);
5210 }
5211 
5212 static inline int ext3_feature_set_ok(struct super_block *sb)
5213 {
5214 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5215 		return 0;
5216 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5217 		return 0;
5218 	if (sb->s_flags & MS_RDONLY)
5219 		return 1;
5220 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5221 		return 0;
5222 	return 1;
5223 }
5224 MODULE_ALIAS("ext3");
5225 #else
5226 static inline void register_as_ext3(void) { }
5227 static inline void unregister_as_ext3(void) { }
5228 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5229 #endif
5230 
5231 static struct file_system_type ext4_fs_type = {
5232 	.owner		= THIS_MODULE,
5233 	.name		= "ext4",
5234 	.mount		= ext4_mount,
5235 	.kill_sb	= kill_block_super,
5236 	.fs_flags	= FS_REQUIRES_DEV,
5237 };
5238 
5239 static int __init ext4_init_feat_adverts(void)
5240 {
5241 	struct ext4_features *ef;
5242 	int ret = -ENOMEM;
5243 
5244 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5245 	if (!ef)
5246 		goto out;
5247 
5248 	ef->f_kobj.kset = ext4_kset;
5249 	init_completion(&ef->f_kobj_unregister);
5250 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5251 				   "features");
5252 	if (ret) {
5253 		kfree(ef);
5254 		goto out;
5255 	}
5256 
5257 	ext4_feat = ef;
5258 	ret = 0;
5259 out:
5260 	return ret;
5261 }
5262 
5263 static void ext4_exit_feat_adverts(void)
5264 {
5265 	kobject_put(&ext4_feat->f_kobj);
5266 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5267 	kfree(ext4_feat);
5268 }
5269 
5270 /* Shared across all ext4 file systems */
5271 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5272 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5273 
5274 static int __init ext4_init_fs(void)
5275 {
5276 	int i, err;
5277 
5278 	ext4_li_info = NULL;
5279 	mutex_init(&ext4_li_mtx);
5280 
5281 	/* Build-time check for flags consistency */
5282 	ext4_check_flag_values();
5283 
5284 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5285 		mutex_init(&ext4__aio_mutex[i]);
5286 		init_waitqueue_head(&ext4__ioend_wq[i]);
5287 	}
5288 
5289 	err = ext4_init_es();
5290 	if (err)
5291 		return err;
5292 
5293 	err = ext4_init_pageio();
5294 	if (err)
5295 		goto out7;
5296 
5297 	err = ext4_init_system_zone();
5298 	if (err)
5299 		goto out6;
5300 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5301 	if (!ext4_kset) {
5302 		err = -ENOMEM;
5303 		goto out5;
5304 	}
5305 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5306 
5307 	err = ext4_init_feat_adverts();
5308 	if (err)
5309 		goto out4;
5310 
5311 	err = ext4_init_mballoc();
5312 	if (err)
5313 		goto out3;
5314 
5315 	err = ext4_init_xattr();
5316 	if (err)
5317 		goto out2;
5318 	err = init_inodecache();
5319 	if (err)
5320 		goto out1;
5321 	register_as_ext3();
5322 	register_as_ext2();
5323 	err = register_filesystem(&ext4_fs_type);
5324 	if (err)
5325 		goto out;
5326 
5327 	return 0;
5328 out:
5329 	unregister_as_ext2();
5330 	unregister_as_ext3();
5331 	destroy_inodecache();
5332 out1:
5333 	ext4_exit_xattr();
5334 out2:
5335 	ext4_exit_mballoc();
5336 out3:
5337 	ext4_exit_feat_adverts();
5338 out4:
5339 	if (ext4_proc_root)
5340 		remove_proc_entry("fs/ext4", NULL);
5341 	kset_unregister(ext4_kset);
5342 out5:
5343 	ext4_exit_system_zone();
5344 out6:
5345 	ext4_exit_pageio();
5346 out7:
5347 	ext4_exit_es();
5348 
5349 	return err;
5350 }
5351 
5352 static void __exit ext4_exit_fs(void)
5353 {
5354 	ext4_destroy_lazyinit_thread();
5355 	unregister_as_ext2();
5356 	unregister_as_ext3();
5357 	unregister_filesystem(&ext4_fs_type);
5358 	destroy_inodecache();
5359 	ext4_exit_xattr();
5360 	ext4_exit_mballoc();
5361 	ext4_exit_feat_adverts();
5362 	remove_proc_entry("fs/ext4", NULL);
5363 	kset_unregister(ext4_kset);
5364 	ext4_exit_system_zone();
5365 	ext4_exit_pageio();
5366 }
5367 
5368 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5369 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5370 MODULE_LICENSE("GPL");
5371 module_init(ext4_init_fs)
5372 module_exit(ext4_exit_fs)
5373