xref: /linux/fs/ext4/super.c (revision 800fb3ddee2c50918d651fbd70515f1e38857305)
1 /*
2  *  linux/fs/ext4/super.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Big-endian to little-endian byte-swapping/bitmaps by
16  *        David S. Miller (davem@caip.rutgers.edu), 1995
17  */
18 
19 #include <linux/module.h>
20 #include <linux/string.h>
21 #include <linux/fs.h>
22 #include <linux/time.h>
23 #include <linux/vmalloc.h>
24 #include <linux/jbd2.h>
25 #include <linux/slab.h>
26 #include <linux/init.h>
27 #include <linux/blkdev.h>
28 #include <linux/parser.h>
29 #include <linux/buffer_head.h>
30 #include <linux/exportfs.h>
31 #include <linux/vfs.h>
32 #include <linux/random.h>
33 #include <linux/mount.h>
34 #include <linux/namei.h>
35 #include <linux/quotaops.h>
36 #include <linux/seq_file.h>
37 #include <linux/proc_fs.h>
38 #include <linux/ctype.h>
39 #include <linux/log2.h>
40 #include <linux/crc16.h>
41 #include <linux/cleancache.h>
42 #include <asm/uaccess.h>
43 
44 #include <linux/kthread.h>
45 #include <linux/freezer.h>
46 
47 #include "ext4.h"
48 #include "ext4_extents.h"
49 #include "ext4_jbd2.h"
50 #include "xattr.h"
51 #include "acl.h"
52 #include "mballoc.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/ext4.h>
56 
57 static struct proc_dir_entry *ext4_proc_root;
58 static struct kset *ext4_kset;
59 static struct ext4_lazy_init *ext4_li_info;
60 static struct mutex ext4_li_mtx;
61 static struct ext4_features *ext4_feat;
62 
63 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
64 			     unsigned long journal_devnum);
65 static int ext4_show_options(struct seq_file *seq, struct dentry *root);
66 static int ext4_commit_super(struct super_block *sb, int sync);
67 static void ext4_mark_recovery_complete(struct super_block *sb,
68 					struct ext4_super_block *es);
69 static void ext4_clear_journal_err(struct super_block *sb,
70 				   struct ext4_super_block *es);
71 static int ext4_sync_fs(struct super_block *sb, int wait);
72 static const char *ext4_decode_error(struct super_block *sb, int errno,
73 				     char nbuf[16]);
74 static int ext4_remount(struct super_block *sb, int *flags, char *data);
75 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
76 static int ext4_unfreeze(struct super_block *sb);
77 static 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 			      struct ext4_super_block *es)
148 {
149 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
150 		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
151 		return;
152 
153 	es->s_checksum = ext4_superblock_csum(sb, es);
154 }
155 
156 void *ext4_kvmalloc(size_t size, gfp_t flags)
157 {
158 	void *ret;
159 
160 	ret = kmalloc(size, flags);
161 	if (!ret)
162 		ret = __vmalloc(size, flags, PAGE_KERNEL);
163 	return ret;
164 }
165 
166 void *ext4_kvzalloc(size_t size, gfp_t flags)
167 {
168 	void *ret;
169 
170 	ret = kzalloc(size, flags);
171 	if (!ret)
172 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
173 	return ret;
174 }
175 
176 void ext4_kvfree(void *ptr)
177 {
178 	if (is_vmalloc_addr(ptr))
179 		vfree(ptr);
180 	else
181 		kfree(ptr);
182 
183 }
184 
185 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
186 			       struct ext4_group_desc *bg)
187 {
188 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
189 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
190 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
191 }
192 
193 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
194 			       struct ext4_group_desc *bg)
195 {
196 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
197 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
198 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
199 }
200 
201 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
202 			      struct ext4_group_desc *bg)
203 {
204 	return le32_to_cpu(bg->bg_inode_table_lo) |
205 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
206 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
207 }
208 
209 __u32 ext4_free_group_clusters(struct super_block *sb,
210 			       struct ext4_group_desc *bg)
211 {
212 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
213 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
214 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
215 }
216 
217 __u32 ext4_free_inodes_count(struct super_block *sb,
218 			      struct ext4_group_desc *bg)
219 {
220 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
221 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
222 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
223 }
224 
225 __u32 ext4_used_dirs_count(struct super_block *sb,
226 			      struct ext4_group_desc *bg)
227 {
228 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
229 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
230 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
231 }
232 
233 __u32 ext4_itable_unused_count(struct super_block *sb,
234 			      struct ext4_group_desc *bg)
235 {
236 	return le16_to_cpu(bg->bg_itable_unused_lo) |
237 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
238 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
239 }
240 
241 void ext4_block_bitmap_set(struct super_block *sb,
242 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
243 {
244 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
245 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
246 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
247 }
248 
249 void ext4_inode_bitmap_set(struct super_block *sb,
250 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
251 {
252 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
253 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
254 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
255 }
256 
257 void ext4_inode_table_set(struct super_block *sb,
258 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
259 {
260 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
261 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
262 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
263 }
264 
265 void ext4_free_group_clusters_set(struct super_block *sb,
266 				  struct ext4_group_desc *bg, __u32 count)
267 {
268 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
269 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
270 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
271 }
272 
273 void ext4_free_inodes_set(struct super_block *sb,
274 			  struct ext4_group_desc *bg, __u32 count)
275 {
276 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
277 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
278 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
279 }
280 
281 void ext4_used_dirs_set(struct super_block *sb,
282 			  struct ext4_group_desc *bg, __u32 count)
283 {
284 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
285 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
286 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
287 }
288 
289 void ext4_itable_unused_set(struct super_block *sb,
290 			  struct ext4_group_desc *bg, __u32 count)
291 {
292 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
293 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
294 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
295 }
296 
297 
298 /* Just increment the non-pointer handle value */
299 static handle_t *ext4_get_nojournal(void)
300 {
301 	handle_t *handle = current->journal_info;
302 	unsigned long ref_cnt = (unsigned long)handle;
303 
304 	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
305 
306 	ref_cnt++;
307 	handle = (handle_t *)ref_cnt;
308 
309 	current->journal_info = handle;
310 	return handle;
311 }
312 
313 
314 /* Decrement the non-pointer handle value */
315 static void ext4_put_nojournal(handle_t *handle)
316 {
317 	unsigned long ref_cnt = (unsigned long)handle;
318 
319 	BUG_ON(ref_cnt == 0);
320 
321 	ref_cnt--;
322 	handle = (handle_t *)ref_cnt;
323 
324 	current->journal_info = handle;
325 }
326 
327 /*
328  * Wrappers for jbd2_journal_start/end.
329  */
330 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
331 {
332 	journal_t *journal;
333 
334 	trace_ext4_journal_start(sb, nblocks, _RET_IP_);
335 	if (sb->s_flags & MS_RDONLY)
336 		return ERR_PTR(-EROFS);
337 
338 	WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
339 	journal = EXT4_SB(sb)->s_journal;
340 	if (!journal)
341 		return ext4_get_nojournal();
342 	/*
343 	 * Special case here: if the journal has aborted behind our
344 	 * backs (eg. EIO in the commit thread), then we still need to
345 	 * take the FS itself readonly cleanly.
346 	 */
347 	if (is_journal_aborted(journal)) {
348 		ext4_abort(sb, "Detected aborted journal");
349 		return ERR_PTR(-EROFS);
350 	}
351 	return jbd2_journal_start(journal, nblocks);
352 }
353 
354 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
355 {
356 	struct super_block *sb;
357 	int err;
358 	int rc;
359 
360 	if (!ext4_handle_valid(handle)) {
361 		ext4_put_nojournal(handle);
362 		return 0;
363 	}
364 	sb = handle->h_transaction->t_journal->j_private;
365 	err = handle->h_err;
366 	rc = jbd2_journal_stop(handle);
367 
368 	if (!err)
369 		err = rc;
370 	if (err)
371 		__ext4_std_error(sb, where, line, err);
372 	return err;
373 }
374 
375 void ext4_journal_abort_handle(const char *caller, unsigned int line,
376 			       const char *err_fn, struct buffer_head *bh,
377 			       handle_t *handle, int err)
378 {
379 	char nbuf[16];
380 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
381 
382 	BUG_ON(!ext4_handle_valid(handle));
383 
384 	if (bh)
385 		BUFFER_TRACE(bh, "abort");
386 
387 	if (!handle->h_err)
388 		handle->h_err = err;
389 
390 	if (is_handle_aborted(handle))
391 		return;
392 
393 	printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
394 	       caller, line, errstr, err_fn);
395 
396 	jbd2_journal_abort_handle(handle);
397 }
398 
399 static void __save_error_info(struct super_block *sb, const char *func,
400 			    unsigned int line)
401 {
402 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
403 
404 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
405 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
406 	es->s_last_error_time = cpu_to_le32(get_seconds());
407 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
408 	es->s_last_error_line = cpu_to_le32(line);
409 	if (!es->s_first_error_time) {
410 		es->s_first_error_time = es->s_last_error_time;
411 		strncpy(es->s_first_error_func, func,
412 			sizeof(es->s_first_error_func));
413 		es->s_first_error_line = cpu_to_le32(line);
414 		es->s_first_error_ino = es->s_last_error_ino;
415 		es->s_first_error_block = es->s_last_error_block;
416 	}
417 	/*
418 	 * Start the daily error reporting function if it hasn't been
419 	 * started already
420 	 */
421 	if (!es->s_error_count)
422 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
423 	es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
424 }
425 
426 static void save_error_info(struct super_block *sb, const char *func,
427 			    unsigned int line)
428 {
429 	__save_error_info(sb, func, line);
430 	ext4_commit_super(sb, 1);
431 }
432 
433 /*
434  * The del_gendisk() function uninitializes the disk-specific data
435  * structures, including the bdi structure, without telling anyone
436  * else.  Once this happens, any attempt to call mark_buffer_dirty()
437  * (for example, by ext4_commit_super), will cause a kernel OOPS.
438  * This is a kludge to prevent these oops until we can put in a proper
439  * hook in del_gendisk() to inform the VFS and file system layers.
440  */
441 static int block_device_ejected(struct super_block *sb)
442 {
443 	struct inode *bd_inode = sb->s_bdev->bd_inode;
444 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
445 
446 	return bdi->dev == NULL;
447 }
448 
449 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
450 {
451 	struct super_block		*sb = journal->j_private;
452 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
453 	int				error = is_journal_aborted(journal);
454 	struct ext4_journal_cb_entry	*jce, *tmp;
455 
456 	spin_lock(&sbi->s_md_lock);
457 	list_for_each_entry_safe(jce, tmp, &txn->t_private_list, jce_list) {
458 		list_del_init(&jce->jce_list);
459 		spin_unlock(&sbi->s_md_lock);
460 		jce->jce_func(sb, jce, error);
461 		spin_lock(&sbi->s_md_lock);
462 	}
463 	spin_unlock(&sbi->s_md_lock);
464 }
465 
466 /* Deal with the reporting of failure conditions on a filesystem such as
467  * inconsistencies detected or read IO failures.
468  *
469  * On ext2, we can store the error state of the filesystem in the
470  * superblock.  That is not possible on ext4, because we may have other
471  * write ordering constraints on the superblock which prevent us from
472  * writing it out straight away; and given that the journal is about to
473  * be aborted, we can't rely on the current, or future, transactions to
474  * write out the superblock safely.
475  *
476  * We'll just use the jbd2_journal_abort() error code to record an error in
477  * the journal instead.  On recovery, the journal will complain about
478  * that error until we've noted it down and cleared it.
479  */
480 
481 static void ext4_handle_error(struct super_block *sb)
482 {
483 	if (sb->s_flags & MS_RDONLY)
484 		return;
485 
486 	if (!test_opt(sb, ERRORS_CONT)) {
487 		journal_t *journal = EXT4_SB(sb)->s_journal;
488 
489 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
490 		if (journal)
491 			jbd2_journal_abort(journal, -EIO);
492 	}
493 	if (test_opt(sb, ERRORS_RO)) {
494 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
495 		sb->s_flags |= MS_RDONLY;
496 	}
497 	if (test_opt(sb, ERRORS_PANIC))
498 		panic("EXT4-fs (device %s): panic forced after error\n",
499 			sb->s_id);
500 }
501 
502 void __ext4_error(struct super_block *sb, const char *function,
503 		  unsigned int line, const char *fmt, ...)
504 {
505 	struct va_format vaf;
506 	va_list args;
507 
508 	va_start(args, fmt);
509 	vaf.fmt = fmt;
510 	vaf.va = &args;
511 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
512 	       sb->s_id, function, line, current->comm, &vaf);
513 	va_end(args);
514 	save_error_info(sb, function, line);
515 
516 	ext4_handle_error(sb);
517 }
518 
519 void ext4_error_inode(struct inode *inode, const char *function,
520 		      unsigned int line, ext4_fsblk_t block,
521 		      const char *fmt, ...)
522 {
523 	va_list args;
524 	struct va_format vaf;
525 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
526 
527 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
528 	es->s_last_error_block = cpu_to_le64(block);
529 	save_error_info(inode->i_sb, function, line);
530 	va_start(args, fmt);
531 	vaf.fmt = fmt;
532 	vaf.va = &args;
533 	if (block)
534 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
535 		       "inode #%lu: block %llu: comm %s: %pV\n",
536 		       inode->i_sb->s_id, function, line, inode->i_ino,
537 		       block, current->comm, &vaf);
538 	else
539 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
540 		       "inode #%lu: comm %s: %pV\n",
541 		       inode->i_sb->s_id, function, line, inode->i_ino,
542 		       current->comm, &vaf);
543 	va_end(args);
544 
545 	ext4_handle_error(inode->i_sb);
546 }
547 
548 void ext4_error_file(struct file *file, const char *function,
549 		     unsigned int line, ext4_fsblk_t block,
550 		     const char *fmt, ...)
551 {
552 	va_list args;
553 	struct va_format vaf;
554 	struct ext4_super_block *es;
555 	struct inode *inode = file->f_dentry->d_inode;
556 	char pathname[80], *path;
557 
558 	es = EXT4_SB(inode->i_sb)->s_es;
559 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
560 	save_error_info(inode->i_sb, function, line);
561 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
562 	if (IS_ERR(path))
563 		path = "(unknown)";
564 	va_start(args, fmt);
565 	vaf.fmt = fmt;
566 	vaf.va = &args;
567 	if (block)
568 		printk(KERN_CRIT
569 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
570 		       "block %llu: comm %s: path %s: %pV\n",
571 		       inode->i_sb->s_id, function, line, inode->i_ino,
572 		       block, current->comm, path, &vaf);
573 	else
574 		printk(KERN_CRIT
575 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
576 		       "comm %s: path %s: %pV\n",
577 		       inode->i_sb->s_id, function, line, inode->i_ino,
578 		       current->comm, path, &vaf);
579 	va_end(args);
580 
581 	ext4_handle_error(inode->i_sb);
582 }
583 
584 static const char *ext4_decode_error(struct super_block *sb, int errno,
585 				     char nbuf[16])
586 {
587 	char *errstr = NULL;
588 
589 	switch (errno) {
590 	case -EIO:
591 		errstr = "IO failure";
592 		break;
593 	case -ENOMEM:
594 		errstr = "Out of memory";
595 		break;
596 	case -EROFS:
597 		if (!sb || (EXT4_SB(sb)->s_journal &&
598 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
599 			errstr = "Journal has aborted";
600 		else
601 			errstr = "Readonly filesystem";
602 		break;
603 	default:
604 		/* If the caller passed in an extra buffer for unknown
605 		 * errors, textualise them now.  Else we just return
606 		 * NULL. */
607 		if (nbuf) {
608 			/* Check for truncated error codes... */
609 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
610 				errstr = nbuf;
611 		}
612 		break;
613 	}
614 
615 	return errstr;
616 }
617 
618 /* __ext4_std_error decodes expected errors from journaling functions
619  * automatically and invokes the appropriate error response.  */
620 
621 void __ext4_std_error(struct super_block *sb, const char *function,
622 		      unsigned int line, int errno)
623 {
624 	char nbuf[16];
625 	const char *errstr;
626 
627 	/* Special case: if the error is EROFS, and we're not already
628 	 * inside a transaction, then there's really no point in logging
629 	 * an error. */
630 	if (errno == -EROFS && journal_current_handle() == NULL &&
631 	    (sb->s_flags & MS_RDONLY))
632 		return;
633 
634 	errstr = ext4_decode_error(sb, errno, nbuf);
635 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
636 	       sb->s_id, function, line, errstr);
637 	save_error_info(sb, function, line);
638 
639 	ext4_handle_error(sb);
640 }
641 
642 /*
643  * ext4_abort is a much stronger failure handler than ext4_error.  The
644  * abort function may be used to deal with unrecoverable failures such
645  * as journal IO errors or ENOMEM at a critical moment in log management.
646  *
647  * We unconditionally force the filesystem into an ABORT|READONLY state,
648  * unless the error response on the fs has been set to panic in which
649  * case we take the easy way out and panic immediately.
650  */
651 
652 void __ext4_abort(struct super_block *sb, const char *function,
653 		unsigned int line, const char *fmt, ...)
654 {
655 	va_list args;
656 
657 	save_error_info(sb, function, line);
658 	va_start(args, fmt);
659 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
660 	       function, line);
661 	vprintk(fmt, args);
662 	printk("\n");
663 	va_end(args);
664 
665 	if ((sb->s_flags & MS_RDONLY) == 0) {
666 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
667 		sb->s_flags |= MS_RDONLY;
668 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
669 		if (EXT4_SB(sb)->s_journal)
670 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
671 		save_error_info(sb, function, line);
672 	}
673 	if (test_opt(sb, ERRORS_PANIC))
674 		panic("EXT4-fs panic from previous error\n");
675 }
676 
677 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
678 {
679 	struct va_format vaf;
680 	va_list args;
681 
682 	va_start(args, fmt);
683 	vaf.fmt = fmt;
684 	vaf.va = &args;
685 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
686 	va_end(args);
687 }
688 
689 void __ext4_warning(struct super_block *sb, const char *function,
690 		    unsigned int line, const char *fmt, ...)
691 {
692 	struct va_format vaf;
693 	va_list args;
694 
695 	va_start(args, fmt);
696 	vaf.fmt = fmt;
697 	vaf.va = &args;
698 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
699 	       sb->s_id, function, line, &vaf);
700 	va_end(args);
701 }
702 
703 void __ext4_grp_locked_error(const char *function, unsigned int line,
704 			     struct super_block *sb, ext4_group_t grp,
705 			     unsigned long ino, ext4_fsblk_t block,
706 			     const char *fmt, ...)
707 __releases(bitlock)
708 __acquires(bitlock)
709 {
710 	struct va_format vaf;
711 	va_list args;
712 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
713 
714 	es->s_last_error_ino = cpu_to_le32(ino);
715 	es->s_last_error_block = cpu_to_le64(block);
716 	__save_error_info(sb, function, line);
717 
718 	va_start(args, fmt);
719 
720 	vaf.fmt = fmt;
721 	vaf.va = &args;
722 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
723 	       sb->s_id, function, line, grp);
724 	if (ino)
725 		printk(KERN_CONT "inode %lu: ", ino);
726 	if (block)
727 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
728 	printk(KERN_CONT "%pV\n", &vaf);
729 	va_end(args);
730 
731 	if (test_opt(sb, ERRORS_CONT)) {
732 		ext4_commit_super(sb, 0);
733 		return;
734 	}
735 
736 	ext4_unlock_group(sb, grp);
737 	ext4_handle_error(sb);
738 	/*
739 	 * We only get here in the ERRORS_RO case; relocking the group
740 	 * may be dangerous, but nothing bad will happen since the
741 	 * filesystem will have already been marked read/only and the
742 	 * journal has been aborted.  We return 1 as a hint to callers
743 	 * who might what to use the return value from
744 	 * ext4_grp_locked_error() to distinguish between the
745 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
746 	 * aggressively from the ext4 function in question, with a
747 	 * more appropriate error code.
748 	 */
749 	ext4_lock_group(sb, grp);
750 	return;
751 }
752 
753 void ext4_update_dynamic_rev(struct super_block *sb)
754 {
755 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
756 
757 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
758 		return;
759 
760 	ext4_warning(sb,
761 		     "updating to rev %d because of new feature flag, "
762 		     "running e2fsck is recommended",
763 		     EXT4_DYNAMIC_REV);
764 
765 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
766 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
767 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
768 	/* leave es->s_feature_*compat flags alone */
769 	/* es->s_uuid will be set by e2fsck if empty */
770 
771 	/*
772 	 * The rest of the superblock fields should be zero, and if not it
773 	 * means they are likely already in use, so leave them alone.  We
774 	 * can leave it up to e2fsck to clean up any inconsistencies there.
775 	 */
776 }
777 
778 /*
779  * Open the external journal device
780  */
781 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
782 {
783 	struct block_device *bdev;
784 	char b[BDEVNAME_SIZE];
785 
786 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
787 	if (IS_ERR(bdev))
788 		goto fail;
789 	return bdev;
790 
791 fail:
792 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
793 			__bdevname(dev, b), PTR_ERR(bdev));
794 	return NULL;
795 }
796 
797 /*
798  * Release the journal device
799  */
800 static int ext4_blkdev_put(struct block_device *bdev)
801 {
802 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
803 }
804 
805 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
806 {
807 	struct block_device *bdev;
808 	int ret = -ENODEV;
809 
810 	bdev = sbi->journal_bdev;
811 	if (bdev) {
812 		ret = ext4_blkdev_put(bdev);
813 		sbi->journal_bdev = NULL;
814 	}
815 	return ret;
816 }
817 
818 static inline struct inode *orphan_list_entry(struct list_head *l)
819 {
820 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
821 }
822 
823 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
824 {
825 	struct list_head *l;
826 
827 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
828 		 le32_to_cpu(sbi->s_es->s_last_orphan));
829 
830 	printk(KERN_ERR "sb_info orphan list:\n");
831 	list_for_each(l, &sbi->s_orphan) {
832 		struct inode *inode = orphan_list_entry(l);
833 		printk(KERN_ERR "  "
834 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
835 		       inode->i_sb->s_id, inode->i_ino, inode,
836 		       inode->i_mode, inode->i_nlink,
837 		       NEXT_ORPHAN(inode));
838 	}
839 }
840 
841 static void ext4_put_super(struct super_block *sb)
842 {
843 	struct ext4_sb_info *sbi = EXT4_SB(sb);
844 	struct ext4_super_block *es = sbi->s_es;
845 	int i, err;
846 
847 	ext4_unregister_li_request(sb);
848 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
849 
850 	flush_workqueue(sbi->dio_unwritten_wq);
851 	destroy_workqueue(sbi->dio_unwritten_wq);
852 
853 	lock_super(sb);
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 	unlock_super(sb);
921 	kobject_put(&sbi->s_kobj);
922 	wait_for_completion(&sbi->s_kobj_unregister);
923 	if (sbi->s_chksum_driver)
924 		crypto_free_shash(sbi->s_chksum_driver);
925 	kfree(sbi->s_blockgroup_lock);
926 	kfree(sbi);
927 }
928 
929 static struct kmem_cache *ext4_inode_cachep;
930 
931 /*
932  * Called inside transaction, so use GFP_NOFS
933  */
934 static struct inode *ext4_alloc_inode(struct super_block *sb)
935 {
936 	struct ext4_inode_info *ei;
937 
938 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
939 	if (!ei)
940 		return NULL;
941 
942 	ei->vfs_inode.i_version = 1;
943 	ei->vfs_inode.i_data.writeback_index = 0;
944 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
945 	INIT_LIST_HEAD(&ei->i_prealloc_list);
946 	spin_lock_init(&ei->i_prealloc_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 	spin_lock_init(&(ei->i_block_reservation_lock));
952 #ifdef CONFIG_QUOTA
953 	ei->i_reserved_quota = 0;
954 #endif
955 	ei->jinode = NULL;
956 	INIT_LIST_HEAD(&ei->i_completed_io_list);
957 	spin_lock_init(&ei->i_completed_io_lock);
958 	ei->cur_aio_dio = NULL;
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_aiodio_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 #ifdef CONFIG_EXT4_FS_XATTR
1001 	init_rwsem(&ei->xattr_sem);
1002 #endif
1003 	init_rwsem(&ei->i_data_sem);
1004 	inode_init_once(&ei->vfs_inode);
1005 }
1006 
1007 static int init_inodecache(void)
1008 {
1009 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1010 					     sizeof(struct ext4_inode_info),
1011 					     0, (SLAB_RECLAIM_ACCOUNT|
1012 						SLAB_MEM_SPREAD),
1013 					     init_once);
1014 	if (ext4_inode_cachep == NULL)
1015 		return -ENOMEM;
1016 	return 0;
1017 }
1018 
1019 static void destroy_inodecache(void)
1020 {
1021 	kmem_cache_destroy(ext4_inode_cachep);
1022 }
1023 
1024 void ext4_clear_inode(struct inode *inode)
1025 {
1026 	invalidate_inode_buffers(inode);
1027 	clear_inode(inode);
1028 	dquot_drop(inode);
1029 	ext4_discard_preallocations(inode);
1030 	if (EXT4_I(inode)->jinode) {
1031 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1032 					       EXT4_I(inode)->jinode);
1033 		jbd2_free_inode(EXT4_I(inode)->jinode);
1034 		EXT4_I(inode)->jinode = NULL;
1035 	}
1036 }
1037 
1038 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1039 					u64 ino, u32 generation)
1040 {
1041 	struct inode *inode;
1042 
1043 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1044 		return ERR_PTR(-ESTALE);
1045 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1046 		return ERR_PTR(-ESTALE);
1047 
1048 	/* iget isn't really right if the inode is currently unallocated!!
1049 	 *
1050 	 * ext4_read_inode will return a bad_inode if the inode had been
1051 	 * deleted, so we should be safe.
1052 	 *
1053 	 * Currently we don't know the generation for parent directory, so
1054 	 * a generation of 0 means "accept any"
1055 	 */
1056 	inode = ext4_iget(sb, ino);
1057 	if (IS_ERR(inode))
1058 		return ERR_CAST(inode);
1059 	if (generation && inode->i_generation != generation) {
1060 		iput(inode);
1061 		return ERR_PTR(-ESTALE);
1062 	}
1063 
1064 	return inode;
1065 }
1066 
1067 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1068 					int fh_len, int fh_type)
1069 {
1070 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1071 				    ext4_nfs_get_inode);
1072 }
1073 
1074 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1075 					int fh_len, int fh_type)
1076 {
1077 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1078 				    ext4_nfs_get_inode);
1079 }
1080 
1081 /*
1082  * Try to release metadata pages (indirect blocks, directories) which are
1083  * mapped via the block device.  Since these pages could have journal heads
1084  * which would prevent try_to_free_buffers() from freeing them, we must use
1085  * jbd2 layer's try_to_free_buffers() function to release them.
1086  */
1087 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1088 				 gfp_t wait)
1089 {
1090 	journal_t *journal = EXT4_SB(sb)->s_journal;
1091 
1092 	WARN_ON(PageChecked(page));
1093 	if (!page_has_buffers(page))
1094 		return 0;
1095 	if (journal)
1096 		return jbd2_journal_try_to_free_buffers(journal, page,
1097 							wait & ~__GFP_WAIT);
1098 	return try_to_free_buffers(page);
1099 }
1100 
1101 #ifdef CONFIG_QUOTA
1102 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1103 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1104 
1105 static int ext4_write_dquot(struct dquot *dquot);
1106 static int ext4_acquire_dquot(struct dquot *dquot);
1107 static int ext4_release_dquot(struct dquot *dquot);
1108 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1109 static int ext4_write_info(struct super_block *sb, int type);
1110 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1111 			 struct path *path);
1112 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1113 				 int format_id);
1114 static int ext4_quota_off(struct super_block *sb, int type);
1115 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1116 static int ext4_quota_on_mount(struct super_block *sb, int type);
1117 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1118 			       size_t len, loff_t off);
1119 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1120 				const char *data, size_t len, loff_t off);
1121 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1122 			     unsigned int flags);
1123 static int ext4_enable_quotas(struct super_block *sb);
1124 
1125 static const struct dquot_operations ext4_quota_operations = {
1126 	.get_reserved_space = ext4_get_reserved_space,
1127 	.write_dquot	= ext4_write_dquot,
1128 	.acquire_dquot	= ext4_acquire_dquot,
1129 	.release_dquot	= ext4_release_dquot,
1130 	.mark_dirty	= ext4_mark_dquot_dirty,
1131 	.write_info	= ext4_write_info,
1132 	.alloc_dquot	= dquot_alloc,
1133 	.destroy_dquot	= dquot_destroy,
1134 };
1135 
1136 static const struct quotactl_ops ext4_qctl_operations = {
1137 	.quota_on	= ext4_quota_on,
1138 	.quota_off	= ext4_quota_off,
1139 	.quota_sync	= dquot_quota_sync,
1140 	.get_info	= dquot_get_dqinfo,
1141 	.set_info	= dquot_set_dqinfo,
1142 	.get_dqblk	= dquot_get_dqblk,
1143 	.set_dqblk	= dquot_set_dqblk
1144 };
1145 
1146 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1147 	.quota_on_meta	= ext4_quota_on_sysfile,
1148 	.quota_off	= ext4_quota_off_sysfile,
1149 	.quota_sync	= dquot_quota_sync,
1150 	.get_info	= dquot_get_dqinfo,
1151 	.set_info	= dquot_set_dqinfo,
1152 	.get_dqblk	= dquot_get_dqblk,
1153 	.set_dqblk	= dquot_set_dqblk
1154 };
1155 #endif
1156 
1157 static const struct super_operations ext4_sops = {
1158 	.alloc_inode	= ext4_alloc_inode,
1159 	.destroy_inode	= ext4_destroy_inode,
1160 	.write_inode	= ext4_write_inode,
1161 	.dirty_inode	= ext4_dirty_inode,
1162 	.drop_inode	= ext4_drop_inode,
1163 	.evict_inode	= ext4_evict_inode,
1164 	.put_super	= ext4_put_super,
1165 	.sync_fs	= ext4_sync_fs,
1166 	.freeze_fs	= ext4_freeze,
1167 	.unfreeze_fs	= ext4_unfreeze,
1168 	.statfs		= ext4_statfs,
1169 	.remount_fs	= ext4_remount,
1170 	.show_options	= ext4_show_options,
1171 #ifdef CONFIG_QUOTA
1172 	.quota_read	= ext4_quota_read,
1173 	.quota_write	= ext4_quota_write,
1174 #endif
1175 	.bdev_try_to_free_page = bdev_try_to_free_page,
1176 };
1177 
1178 static const struct super_operations ext4_nojournal_sops = {
1179 	.alloc_inode	= ext4_alloc_inode,
1180 	.destroy_inode	= ext4_destroy_inode,
1181 	.write_inode	= ext4_write_inode,
1182 	.dirty_inode	= ext4_dirty_inode,
1183 	.drop_inode	= ext4_drop_inode,
1184 	.evict_inode	= ext4_evict_inode,
1185 	.put_super	= ext4_put_super,
1186 	.statfs		= ext4_statfs,
1187 	.remount_fs	= ext4_remount,
1188 	.show_options	= ext4_show_options,
1189 #ifdef CONFIG_QUOTA
1190 	.quota_read	= ext4_quota_read,
1191 	.quota_write	= ext4_quota_write,
1192 #endif
1193 	.bdev_try_to_free_page = bdev_try_to_free_page,
1194 };
1195 
1196 static const struct export_operations ext4_export_ops = {
1197 	.fh_to_dentry = ext4_fh_to_dentry,
1198 	.fh_to_parent = ext4_fh_to_parent,
1199 	.get_parent = ext4_get_parent,
1200 };
1201 
1202 enum {
1203 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1204 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1205 	Opt_nouid32, Opt_debug, Opt_removed,
1206 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1207 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1208 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1209 	Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1210 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1211 	Opt_data_err_abort, Opt_data_err_ignore,
1212 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1213 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1214 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1215 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1216 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1217 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1218 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1219 	Opt_dioread_nolock, Opt_dioread_lock,
1220 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1221 };
1222 
1223 static const match_table_t tokens = {
1224 	{Opt_bsd_df, "bsddf"},
1225 	{Opt_minix_df, "minixdf"},
1226 	{Opt_grpid, "grpid"},
1227 	{Opt_grpid, "bsdgroups"},
1228 	{Opt_nogrpid, "nogrpid"},
1229 	{Opt_nogrpid, "sysvgroups"},
1230 	{Opt_resgid, "resgid=%u"},
1231 	{Opt_resuid, "resuid=%u"},
1232 	{Opt_sb, "sb=%u"},
1233 	{Opt_err_cont, "errors=continue"},
1234 	{Opt_err_panic, "errors=panic"},
1235 	{Opt_err_ro, "errors=remount-ro"},
1236 	{Opt_nouid32, "nouid32"},
1237 	{Opt_debug, "debug"},
1238 	{Opt_removed, "oldalloc"},
1239 	{Opt_removed, "orlov"},
1240 	{Opt_user_xattr, "user_xattr"},
1241 	{Opt_nouser_xattr, "nouser_xattr"},
1242 	{Opt_acl, "acl"},
1243 	{Opt_noacl, "noacl"},
1244 	{Opt_noload, "norecovery"},
1245 	{Opt_noload, "noload"},
1246 	{Opt_removed, "nobh"},
1247 	{Opt_removed, "bh"},
1248 	{Opt_commit, "commit=%u"},
1249 	{Opt_min_batch_time, "min_batch_time=%u"},
1250 	{Opt_max_batch_time, "max_batch_time=%u"},
1251 	{Opt_journal_dev, "journal_dev=%u"},
1252 	{Opt_journal_checksum, "journal_checksum"},
1253 	{Opt_journal_async_commit, "journal_async_commit"},
1254 	{Opt_abort, "abort"},
1255 	{Opt_data_journal, "data=journal"},
1256 	{Opt_data_ordered, "data=ordered"},
1257 	{Opt_data_writeback, "data=writeback"},
1258 	{Opt_data_err_abort, "data_err=abort"},
1259 	{Opt_data_err_ignore, "data_err=ignore"},
1260 	{Opt_offusrjquota, "usrjquota="},
1261 	{Opt_usrjquota, "usrjquota=%s"},
1262 	{Opt_offgrpjquota, "grpjquota="},
1263 	{Opt_grpjquota, "grpjquota=%s"},
1264 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1265 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1266 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1267 	{Opt_grpquota, "grpquota"},
1268 	{Opt_noquota, "noquota"},
1269 	{Opt_quota, "quota"},
1270 	{Opt_usrquota, "usrquota"},
1271 	{Opt_barrier, "barrier=%u"},
1272 	{Opt_barrier, "barrier"},
1273 	{Opt_nobarrier, "nobarrier"},
1274 	{Opt_i_version, "i_version"},
1275 	{Opt_stripe, "stripe=%u"},
1276 	{Opt_delalloc, "delalloc"},
1277 	{Opt_nodelalloc, "nodelalloc"},
1278 	{Opt_mblk_io_submit, "mblk_io_submit"},
1279 	{Opt_nomblk_io_submit, "nomblk_io_submit"},
1280 	{Opt_block_validity, "block_validity"},
1281 	{Opt_noblock_validity, "noblock_validity"},
1282 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1283 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1284 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1285 	{Opt_auto_da_alloc, "auto_da_alloc"},
1286 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1287 	{Opt_dioread_nolock, "dioread_nolock"},
1288 	{Opt_dioread_lock, "dioread_lock"},
1289 	{Opt_discard, "discard"},
1290 	{Opt_nodiscard, "nodiscard"},
1291 	{Opt_init_itable, "init_itable=%u"},
1292 	{Opt_init_itable, "init_itable"},
1293 	{Opt_noinit_itable, "noinit_itable"},
1294 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1295 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1296 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1297 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1298 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1299 	{Opt_err, NULL},
1300 };
1301 
1302 static ext4_fsblk_t get_sb_block(void **data)
1303 {
1304 	ext4_fsblk_t	sb_block;
1305 	char		*options = (char *) *data;
1306 
1307 	if (!options || strncmp(options, "sb=", 3) != 0)
1308 		return 1;	/* Default location */
1309 
1310 	options += 3;
1311 	/* TODO: use simple_strtoll with >32bit ext4 */
1312 	sb_block = simple_strtoul(options, &options, 0);
1313 	if (*options && *options != ',') {
1314 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1315 		       (char *) *data);
1316 		return 1;
1317 	}
1318 	if (*options == ',')
1319 		options++;
1320 	*data = (void *) options;
1321 
1322 	return sb_block;
1323 }
1324 
1325 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1326 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1327 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1328 
1329 #ifdef CONFIG_QUOTA
1330 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1331 {
1332 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1333 	char *qname;
1334 
1335 	if (sb_any_quota_loaded(sb) &&
1336 		!sbi->s_qf_names[qtype]) {
1337 		ext4_msg(sb, KERN_ERR,
1338 			"Cannot change journaled "
1339 			"quota options when quota turned on");
1340 		return -1;
1341 	}
1342 	qname = match_strdup(args);
1343 	if (!qname) {
1344 		ext4_msg(sb, KERN_ERR,
1345 			"Not enough memory for storing quotafile name");
1346 		return -1;
1347 	}
1348 	if (sbi->s_qf_names[qtype] &&
1349 		strcmp(sbi->s_qf_names[qtype], qname)) {
1350 		ext4_msg(sb, KERN_ERR,
1351 			"%s quota file already specified", QTYPE2NAME(qtype));
1352 		kfree(qname);
1353 		return -1;
1354 	}
1355 	sbi->s_qf_names[qtype] = qname;
1356 	if (strchr(sbi->s_qf_names[qtype], '/')) {
1357 		ext4_msg(sb, KERN_ERR,
1358 			"quotafile must be on filesystem root");
1359 		kfree(sbi->s_qf_names[qtype]);
1360 		sbi->s_qf_names[qtype] = NULL;
1361 		return -1;
1362 	}
1363 	set_opt(sb, QUOTA);
1364 	return 1;
1365 }
1366 
1367 static int clear_qf_name(struct super_block *sb, int qtype)
1368 {
1369 
1370 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1371 
1372 	if (sb_any_quota_loaded(sb) &&
1373 		sbi->s_qf_names[qtype]) {
1374 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1375 			" when quota turned on");
1376 		return -1;
1377 	}
1378 	/*
1379 	 * The space will be released later when all options are confirmed
1380 	 * to be correct
1381 	 */
1382 	sbi->s_qf_names[qtype] = NULL;
1383 	return 1;
1384 }
1385 #endif
1386 
1387 #define MOPT_SET	0x0001
1388 #define MOPT_CLEAR	0x0002
1389 #define MOPT_NOSUPPORT	0x0004
1390 #define MOPT_EXPLICIT	0x0008
1391 #define MOPT_CLEAR_ERR	0x0010
1392 #define MOPT_GTE0	0x0020
1393 #ifdef CONFIG_QUOTA
1394 #define MOPT_Q		0
1395 #define MOPT_QFMT	0x0040
1396 #else
1397 #define MOPT_Q		MOPT_NOSUPPORT
1398 #define MOPT_QFMT	MOPT_NOSUPPORT
1399 #endif
1400 #define MOPT_DATAJ	0x0080
1401 
1402 static const struct mount_opts {
1403 	int	token;
1404 	int	mount_opt;
1405 	int	flags;
1406 } ext4_mount_opts[] = {
1407 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1408 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1409 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1410 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1411 	{Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
1412 	{Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
1413 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1414 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1415 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
1416 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_CLEAR},
1417 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1418 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1419 	{Opt_delalloc, EXT4_MOUNT_DELALLOC, MOPT_SET | MOPT_EXPLICIT},
1420 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC, MOPT_CLEAR | MOPT_EXPLICIT},
1421 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM, MOPT_SET},
1422 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1423 				    EXT4_MOUNT_JOURNAL_CHECKSUM), MOPT_SET},
1424 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_SET},
1425 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1426 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1427 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1428 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_SET},
1429 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_CLEAR},
1430 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1431 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1432 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1433 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1434 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1435 	{Opt_commit, 0, MOPT_GTE0},
1436 	{Opt_max_batch_time, 0, MOPT_GTE0},
1437 	{Opt_min_batch_time, 0, MOPT_GTE0},
1438 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1439 	{Opt_init_itable, 0, MOPT_GTE0},
1440 	{Opt_stripe, 0, MOPT_GTE0},
1441 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
1442 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
1443 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
1444 #ifdef CONFIG_EXT4_FS_XATTR
1445 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1446 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1447 #else
1448 	{Opt_user_xattr, 0, MOPT_NOSUPPORT},
1449 	{Opt_nouser_xattr, 0, MOPT_NOSUPPORT},
1450 #endif
1451 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1452 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1453 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1454 #else
1455 	{Opt_acl, 0, MOPT_NOSUPPORT},
1456 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1457 #endif
1458 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1459 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1460 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1461 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1462 							MOPT_SET | MOPT_Q},
1463 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1464 							MOPT_SET | MOPT_Q},
1465 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1466 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1467 	{Opt_usrjquota, 0, MOPT_Q},
1468 	{Opt_grpjquota, 0, MOPT_Q},
1469 	{Opt_offusrjquota, 0, MOPT_Q},
1470 	{Opt_offgrpjquota, 0, MOPT_Q},
1471 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1472 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1473 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1474 	{Opt_err, 0, 0}
1475 };
1476 
1477 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1478 			    substring_t *args, unsigned long *journal_devnum,
1479 			    unsigned int *journal_ioprio, int is_remount)
1480 {
1481 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1482 	const struct mount_opts *m;
1483 	kuid_t uid;
1484 	kgid_t gid;
1485 	int arg = 0;
1486 
1487 #ifdef CONFIG_QUOTA
1488 	if (token == Opt_usrjquota)
1489 		return set_qf_name(sb, USRQUOTA, &args[0]);
1490 	else if (token == Opt_grpjquota)
1491 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1492 	else if (token == Opt_offusrjquota)
1493 		return clear_qf_name(sb, USRQUOTA);
1494 	else if (token == Opt_offgrpjquota)
1495 		return clear_qf_name(sb, GRPQUOTA);
1496 #endif
1497 	if (args->from && match_int(args, &arg))
1498 		return -1;
1499 	switch (token) {
1500 	case Opt_noacl:
1501 	case Opt_nouser_xattr:
1502 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1503 		break;
1504 	case Opt_sb:
1505 		return 1;	/* handled by get_sb_block() */
1506 	case Opt_removed:
1507 		ext4_msg(sb, KERN_WARNING,
1508 			 "Ignoring removed %s option", opt);
1509 		return 1;
1510 	case Opt_resuid:
1511 		uid = make_kuid(current_user_ns(), arg);
1512 		if (!uid_valid(uid)) {
1513 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1514 			return -1;
1515 		}
1516 		sbi->s_resuid = uid;
1517 		return 1;
1518 	case Opt_resgid:
1519 		gid = make_kgid(current_user_ns(), arg);
1520 		if (!gid_valid(gid)) {
1521 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1522 			return -1;
1523 		}
1524 		sbi->s_resgid = gid;
1525 		return 1;
1526 	case Opt_abort:
1527 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1528 		return 1;
1529 	case Opt_i_version:
1530 		sb->s_flags |= MS_I_VERSION;
1531 		return 1;
1532 	case Opt_journal_dev:
1533 		if (is_remount) {
1534 			ext4_msg(sb, KERN_ERR,
1535 				 "Cannot specify journal on remount");
1536 			return -1;
1537 		}
1538 		*journal_devnum = arg;
1539 		return 1;
1540 	case Opt_journal_ioprio:
1541 		if (arg < 0 || arg > 7)
1542 			return -1;
1543 		*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1544 		return 1;
1545 	}
1546 
1547 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1548 		if (token != m->token)
1549 			continue;
1550 		if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1551 			return -1;
1552 		if (m->flags & MOPT_EXPLICIT)
1553 			set_opt2(sb, EXPLICIT_DELALLOC);
1554 		if (m->flags & MOPT_CLEAR_ERR)
1555 			clear_opt(sb, ERRORS_MASK);
1556 		if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1557 			ext4_msg(sb, KERN_ERR, "Cannot change quota "
1558 				 "options when quota turned on");
1559 			return -1;
1560 		}
1561 
1562 		if (m->flags & MOPT_NOSUPPORT) {
1563 			ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1564 		} else if (token == Opt_commit) {
1565 			if (arg == 0)
1566 				arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1567 			sbi->s_commit_interval = HZ * arg;
1568 		} else if (token == Opt_max_batch_time) {
1569 			if (arg == 0)
1570 				arg = EXT4_DEF_MAX_BATCH_TIME;
1571 			sbi->s_max_batch_time = arg;
1572 		} else if (token == Opt_min_batch_time) {
1573 			sbi->s_min_batch_time = arg;
1574 		} else if (token == Opt_inode_readahead_blks) {
1575 			if (arg > (1 << 30))
1576 				return -1;
1577 			if (arg && !is_power_of_2(arg)) {
1578 				ext4_msg(sb, KERN_ERR,
1579 					 "EXT4-fs: inode_readahead_blks"
1580 					 " must be a power of 2");
1581 				return -1;
1582 			}
1583 			sbi->s_inode_readahead_blks = arg;
1584 		} else if (token == Opt_init_itable) {
1585 			set_opt(sb, INIT_INODE_TABLE);
1586 			if (!args->from)
1587 				arg = EXT4_DEF_LI_WAIT_MULT;
1588 			sbi->s_li_wait_mult = arg;
1589 		} else if (token == Opt_stripe) {
1590 			sbi->s_stripe = arg;
1591 		} else if (m->flags & MOPT_DATAJ) {
1592 			if (is_remount) {
1593 				if (!sbi->s_journal)
1594 					ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1595 				else if (test_opt(sb, DATA_FLAGS) !=
1596 					 m->mount_opt) {
1597 					ext4_msg(sb, KERN_ERR,
1598 					 "Cannot change data mode on remount");
1599 					return -1;
1600 				}
1601 			} else {
1602 				clear_opt(sb, DATA_FLAGS);
1603 				sbi->s_mount_opt |= m->mount_opt;
1604 			}
1605 #ifdef CONFIG_QUOTA
1606 		} else if (m->flags & MOPT_QFMT) {
1607 			if (sb_any_quota_loaded(sb) &&
1608 			    sbi->s_jquota_fmt != m->mount_opt) {
1609 				ext4_msg(sb, KERN_ERR, "Cannot "
1610 					 "change journaled quota options "
1611 					 "when quota turned on");
1612 				return -1;
1613 			}
1614 			sbi->s_jquota_fmt = m->mount_opt;
1615 #endif
1616 		} else {
1617 			if (!args->from)
1618 				arg = 1;
1619 			if (m->flags & MOPT_CLEAR)
1620 				arg = !arg;
1621 			else if (unlikely(!(m->flags & MOPT_SET))) {
1622 				ext4_msg(sb, KERN_WARNING,
1623 					 "buggy handling of option %s", opt);
1624 				WARN_ON(1);
1625 				return -1;
1626 			}
1627 			if (arg != 0)
1628 				sbi->s_mount_opt |= m->mount_opt;
1629 			else
1630 				sbi->s_mount_opt &= ~m->mount_opt;
1631 		}
1632 		return 1;
1633 	}
1634 	ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1635 		 "or missing value", opt);
1636 	return -1;
1637 }
1638 
1639 static int parse_options(char *options, struct super_block *sb,
1640 			 unsigned long *journal_devnum,
1641 			 unsigned int *journal_ioprio,
1642 			 int is_remount)
1643 {
1644 #ifdef CONFIG_QUOTA
1645 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1646 #endif
1647 	char *p;
1648 	substring_t args[MAX_OPT_ARGS];
1649 	int token;
1650 
1651 	if (!options)
1652 		return 1;
1653 
1654 	while ((p = strsep(&options, ",")) != NULL) {
1655 		if (!*p)
1656 			continue;
1657 		/*
1658 		 * Initialize args struct so we know whether arg was
1659 		 * found; some options take optional arguments.
1660 		 */
1661 		args[0].to = args[0].from = 0;
1662 		token = match_token(p, tokens, args);
1663 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1664 				     journal_ioprio, is_remount) < 0)
1665 			return 0;
1666 	}
1667 #ifdef CONFIG_QUOTA
1668 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1669 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1670 			clear_opt(sb, USRQUOTA);
1671 
1672 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1673 			clear_opt(sb, GRPQUOTA);
1674 
1675 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1676 			ext4_msg(sb, KERN_ERR, "old and new quota "
1677 					"format mixing");
1678 			return 0;
1679 		}
1680 
1681 		if (!sbi->s_jquota_fmt) {
1682 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1683 					"not specified");
1684 			return 0;
1685 		}
1686 	} else {
1687 		if (sbi->s_jquota_fmt) {
1688 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1689 					"specified with no journaling "
1690 					"enabled");
1691 			return 0;
1692 		}
1693 	}
1694 #endif
1695 	return 1;
1696 }
1697 
1698 static inline void ext4_show_quota_options(struct seq_file *seq,
1699 					   struct super_block *sb)
1700 {
1701 #if defined(CONFIG_QUOTA)
1702 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1703 
1704 	if (sbi->s_jquota_fmt) {
1705 		char *fmtname = "";
1706 
1707 		switch (sbi->s_jquota_fmt) {
1708 		case QFMT_VFS_OLD:
1709 			fmtname = "vfsold";
1710 			break;
1711 		case QFMT_VFS_V0:
1712 			fmtname = "vfsv0";
1713 			break;
1714 		case QFMT_VFS_V1:
1715 			fmtname = "vfsv1";
1716 			break;
1717 		}
1718 		seq_printf(seq, ",jqfmt=%s", fmtname);
1719 	}
1720 
1721 	if (sbi->s_qf_names[USRQUOTA])
1722 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1723 
1724 	if (sbi->s_qf_names[GRPQUOTA])
1725 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1726 
1727 	if (test_opt(sb, USRQUOTA))
1728 		seq_puts(seq, ",usrquota");
1729 
1730 	if (test_opt(sb, GRPQUOTA))
1731 		seq_puts(seq, ",grpquota");
1732 #endif
1733 }
1734 
1735 static const char *token2str(int token)
1736 {
1737 	static const struct match_token *t;
1738 
1739 	for (t = tokens; t->token != Opt_err; t++)
1740 		if (t->token == token && !strchr(t->pattern, '='))
1741 			break;
1742 	return t->pattern;
1743 }
1744 
1745 /*
1746  * Show an option if
1747  *  - it's set to a non-default value OR
1748  *  - if the per-sb default is different from the global default
1749  */
1750 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1751 			      int nodefs)
1752 {
1753 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1754 	struct ext4_super_block *es = sbi->s_es;
1755 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1756 	const struct mount_opts *m;
1757 	char sep = nodefs ? '\n' : ',';
1758 
1759 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1760 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1761 
1762 	if (sbi->s_sb_block != 1)
1763 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1764 
1765 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1766 		int want_set = m->flags & MOPT_SET;
1767 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1768 		    (m->flags & MOPT_CLEAR_ERR))
1769 			continue;
1770 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1771 			continue; /* skip if same as the default */
1772 		if ((want_set &&
1773 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1774 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1775 			continue; /* select Opt_noFoo vs Opt_Foo */
1776 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1777 	}
1778 
1779 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1780 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1781 		SEQ_OPTS_PRINT("resuid=%u",
1782 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1783 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1784 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1785 		SEQ_OPTS_PRINT("resgid=%u",
1786 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1787 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1788 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1789 		SEQ_OPTS_PUTS("errors=remount-ro");
1790 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1791 		SEQ_OPTS_PUTS("errors=continue");
1792 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1793 		SEQ_OPTS_PUTS("errors=panic");
1794 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1795 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1796 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1797 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1798 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1799 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1800 	if (sb->s_flags & MS_I_VERSION)
1801 		SEQ_OPTS_PUTS("i_version");
1802 	if (nodefs || sbi->s_stripe)
1803 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1804 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1805 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1806 			SEQ_OPTS_PUTS("data=journal");
1807 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1808 			SEQ_OPTS_PUTS("data=ordered");
1809 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1810 			SEQ_OPTS_PUTS("data=writeback");
1811 	}
1812 	if (nodefs ||
1813 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1814 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1815 			       sbi->s_inode_readahead_blks);
1816 
1817 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1818 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1819 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1820 
1821 	ext4_show_quota_options(seq, sb);
1822 	return 0;
1823 }
1824 
1825 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1826 {
1827 	return _ext4_show_options(seq, root->d_sb, 0);
1828 }
1829 
1830 static int options_seq_show(struct seq_file *seq, void *offset)
1831 {
1832 	struct super_block *sb = seq->private;
1833 	int rc;
1834 
1835 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1836 	rc = _ext4_show_options(seq, sb, 1);
1837 	seq_puts(seq, "\n");
1838 	return rc;
1839 }
1840 
1841 static int options_open_fs(struct inode *inode, struct file *file)
1842 {
1843 	return single_open(file, options_seq_show, PDE(inode)->data);
1844 }
1845 
1846 static const struct file_operations ext4_seq_options_fops = {
1847 	.owner = THIS_MODULE,
1848 	.open = options_open_fs,
1849 	.read = seq_read,
1850 	.llseek = seq_lseek,
1851 	.release = single_release,
1852 };
1853 
1854 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1855 			    int read_only)
1856 {
1857 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1858 	int res = 0;
1859 
1860 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1861 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1862 			 "forcing read-only mode");
1863 		res = MS_RDONLY;
1864 	}
1865 	if (read_only)
1866 		goto done;
1867 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1868 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1869 			 "running e2fsck is recommended");
1870 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1871 		ext4_msg(sb, KERN_WARNING,
1872 			 "warning: mounting fs with errors, "
1873 			 "running e2fsck is recommended");
1874 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1875 		 le16_to_cpu(es->s_mnt_count) >=
1876 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1877 		ext4_msg(sb, KERN_WARNING,
1878 			 "warning: maximal mount count reached, "
1879 			 "running e2fsck is recommended");
1880 	else if (le32_to_cpu(es->s_checkinterval) &&
1881 		(le32_to_cpu(es->s_lastcheck) +
1882 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1883 		ext4_msg(sb, KERN_WARNING,
1884 			 "warning: checktime reached, "
1885 			 "running e2fsck is recommended");
1886 	if (!sbi->s_journal)
1887 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1888 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1889 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1890 	le16_add_cpu(&es->s_mnt_count, 1);
1891 	es->s_mtime = cpu_to_le32(get_seconds());
1892 	ext4_update_dynamic_rev(sb);
1893 	if (sbi->s_journal)
1894 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1895 
1896 	ext4_commit_super(sb, 1);
1897 done:
1898 	if (test_opt(sb, DEBUG))
1899 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1900 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1901 			sb->s_blocksize,
1902 			sbi->s_groups_count,
1903 			EXT4_BLOCKS_PER_GROUP(sb),
1904 			EXT4_INODES_PER_GROUP(sb),
1905 			sbi->s_mount_opt, sbi->s_mount_opt2);
1906 
1907 	cleancache_init_fs(sb);
1908 	return res;
1909 }
1910 
1911 static int ext4_fill_flex_info(struct super_block *sb)
1912 {
1913 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1914 	struct ext4_group_desc *gdp = NULL;
1915 	ext4_group_t flex_group_count;
1916 	ext4_group_t flex_group;
1917 	unsigned int groups_per_flex = 0;
1918 	size_t size;
1919 	int i;
1920 
1921 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1922 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1923 		sbi->s_log_groups_per_flex = 0;
1924 		return 1;
1925 	}
1926 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1927 
1928 	/* We allocate both existing and potentially added groups */
1929 	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1930 			((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1931 			      EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1932 	size = flex_group_count * sizeof(struct flex_groups);
1933 	sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
1934 	if (sbi->s_flex_groups == NULL) {
1935 		ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
1936 			 flex_group_count);
1937 		goto failed;
1938 	}
1939 
1940 	for (i = 0; i < sbi->s_groups_count; i++) {
1941 		gdp = ext4_get_group_desc(sb, i, NULL);
1942 
1943 		flex_group = ext4_flex_group(sbi, i);
1944 		atomic_add(ext4_free_inodes_count(sb, gdp),
1945 			   &sbi->s_flex_groups[flex_group].free_inodes);
1946 		atomic_add(ext4_free_group_clusters(sb, gdp),
1947 			   &sbi->s_flex_groups[flex_group].free_clusters);
1948 		atomic_add(ext4_used_dirs_count(sb, gdp),
1949 			   &sbi->s_flex_groups[flex_group].used_dirs);
1950 	}
1951 
1952 	return 1;
1953 failed:
1954 	return 0;
1955 }
1956 
1957 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1958 				   struct ext4_group_desc *gdp)
1959 {
1960 	int offset;
1961 	__u16 crc = 0;
1962 	__le32 le_group = cpu_to_le32(block_group);
1963 
1964 	if ((sbi->s_es->s_feature_ro_compat &
1965 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1966 		/* Use new metadata_csum algorithm */
1967 		__u16 old_csum;
1968 		__u32 csum32;
1969 
1970 		old_csum = gdp->bg_checksum;
1971 		gdp->bg_checksum = 0;
1972 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1973 				     sizeof(le_group));
1974 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1975 				     sbi->s_desc_size);
1976 		gdp->bg_checksum = old_csum;
1977 
1978 		crc = csum32 & 0xFFFF;
1979 		goto out;
1980 	}
1981 
1982 	/* old crc16 code */
1983 	offset = offsetof(struct ext4_group_desc, bg_checksum);
1984 
1985 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1986 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1987 	crc = crc16(crc, (__u8 *)gdp, offset);
1988 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
1989 	/* for checksum of struct ext4_group_desc do the rest...*/
1990 	if ((sbi->s_es->s_feature_incompat &
1991 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1992 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1993 		crc = crc16(crc, (__u8 *)gdp + offset,
1994 			    le16_to_cpu(sbi->s_es->s_desc_size) -
1995 				offset);
1996 
1997 out:
1998 	return cpu_to_le16(crc);
1999 }
2000 
2001 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2002 				struct ext4_group_desc *gdp)
2003 {
2004 	if (ext4_has_group_desc_csum(sb) &&
2005 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2006 						      block_group, gdp)))
2007 		return 0;
2008 
2009 	return 1;
2010 }
2011 
2012 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2013 			      struct ext4_group_desc *gdp)
2014 {
2015 	if (!ext4_has_group_desc_csum(sb))
2016 		return;
2017 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2018 }
2019 
2020 /* Called at mount-time, super-block is locked */
2021 static int ext4_check_descriptors(struct super_block *sb,
2022 				  ext4_group_t *first_not_zeroed)
2023 {
2024 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2025 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2026 	ext4_fsblk_t last_block;
2027 	ext4_fsblk_t block_bitmap;
2028 	ext4_fsblk_t inode_bitmap;
2029 	ext4_fsblk_t inode_table;
2030 	int flexbg_flag = 0;
2031 	ext4_group_t i, grp = sbi->s_groups_count;
2032 
2033 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2034 		flexbg_flag = 1;
2035 
2036 	ext4_debug("Checking group descriptors");
2037 
2038 	for (i = 0; i < sbi->s_groups_count; i++) {
2039 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2040 
2041 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2042 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2043 		else
2044 			last_block = first_block +
2045 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2046 
2047 		if ((grp == sbi->s_groups_count) &&
2048 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2049 			grp = i;
2050 
2051 		block_bitmap = ext4_block_bitmap(sb, gdp);
2052 		if (block_bitmap < first_block || block_bitmap > last_block) {
2053 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2054 			       "Block bitmap for group %u not in group "
2055 			       "(block %llu)!", i, block_bitmap);
2056 			return 0;
2057 		}
2058 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2059 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2060 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2061 			       "Inode bitmap for group %u not in group "
2062 			       "(block %llu)!", i, inode_bitmap);
2063 			return 0;
2064 		}
2065 		inode_table = ext4_inode_table(sb, gdp);
2066 		if (inode_table < first_block ||
2067 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2068 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2069 			       "Inode table for group %u not in group "
2070 			       "(block %llu)!", i, inode_table);
2071 			return 0;
2072 		}
2073 		ext4_lock_group(sb, i);
2074 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2075 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2076 				 "Checksum for group %u failed (%u!=%u)",
2077 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2078 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2079 			if (!(sb->s_flags & MS_RDONLY)) {
2080 				ext4_unlock_group(sb, i);
2081 				return 0;
2082 			}
2083 		}
2084 		ext4_unlock_group(sb, i);
2085 		if (!flexbg_flag)
2086 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2087 	}
2088 	if (NULL != first_not_zeroed)
2089 		*first_not_zeroed = grp;
2090 
2091 	ext4_free_blocks_count_set(sbi->s_es,
2092 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2093 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2094 	return 1;
2095 }
2096 
2097 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2098  * the superblock) which were deleted from all directories, but held open by
2099  * a process at the time of a crash.  We walk the list and try to delete these
2100  * inodes at recovery time (only with a read-write filesystem).
2101  *
2102  * In order to keep the orphan inode chain consistent during traversal (in
2103  * case of crash during recovery), we link each inode into the superblock
2104  * orphan list_head and handle it the same way as an inode deletion during
2105  * normal operation (which journals the operations for us).
2106  *
2107  * We only do an iget() and an iput() on each inode, which is very safe if we
2108  * accidentally point at an in-use or already deleted inode.  The worst that
2109  * can happen in this case is that we get a "bit already cleared" message from
2110  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2111  * e2fsck was run on this filesystem, and it must have already done the orphan
2112  * inode cleanup for us, so we can safely abort without any further action.
2113  */
2114 static void ext4_orphan_cleanup(struct super_block *sb,
2115 				struct ext4_super_block *es)
2116 {
2117 	unsigned int s_flags = sb->s_flags;
2118 	int nr_orphans = 0, nr_truncates = 0;
2119 #ifdef CONFIG_QUOTA
2120 	int i;
2121 #endif
2122 	if (!es->s_last_orphan) {
2123 		jbd_debug(4, "no orphan inodes to clean up\n");
2124 		return;
2125 	}
2126 
2127 	if (bdev_read_only(sb->s_bdev)) {
2128 		ext4_msg(sb, KERN_ERR, "write access "
2129 			"unavailable, skipping orphan cleanup");
2130 		return;
2131 	}
2132 
2133 	/* Check if feature set would not allow a r/w mount */
2134 	if (!ext4_feature_set_ok(sb, 0)) {
2135 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2136 			 "unknown ROCOMPAT features");
2137 		return;
2138 	}
2139 
2140 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2141 		if (es->s_last_orphan)
2142 			jbd_debug(1, "Errors on filesystem, "
2143 				  "clearing orphan list.\n");
2144 		es->s_last_orphan = 0;
2145 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2146 		return;
2147 	}
2148 
2149 	if (s_flags & MS_RDONLY) {
2150 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2151 		sb->s_flags &= ~MS_RDONLY;
2152 	}
2153 #ifdef CONFIG_QUOTA
2154 	/* Needed for iput() to work correctly and not trash data */
2155 	sb->s_flags |= MS_ACTIVE;
2156 	/* Turn on quotas so that they are updated correctly */
2157 	for (i = 0; i < MAXQUOTAS; i++) {
2158 		if (EXT4_SB(sb)->s_qf_names[i]) {
2159 			int ret = ext4_quota_on_mount(sb, i);
2160 			if (ret < 0)
2161 				ext4_msg(sb, KERN_ERR,
2162 					"Cannot turn on journaled "
2163 					"quota: error %d", ret);
2164 		}
2165 	}
2166 #endif
2167 
2168 	while (es->s_last_orphan) {
2169 		struct inode *inode;
2170 
2171 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2172 		if (IS_ERR(inode)) {
2173 			es->s_last_orphan = 0;
2174 			break;
2175 		}
2176 
2177 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2178 		dquot_initialize(inode);
2179 		if (inode->i_nlink) {
2180 			ext4_msg(sb, KERN_DEBUG,
2181 				"%s: truncating inode %lu to %lld bytes",
2182 				__func__, inode->i_ino, inode->i_size);
2183 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2184 				  inode->i_ino, inode->i_size);
2185 			ext4_truncate(inode);
2186 			nr_truncates++;
2187 		} else {
2188 			ext4_msg(sb, KERN_DEBUG,
2189 				"%s: deleting unreferenced inode %lu",
2190 				__func__, inode->i_ino);
2191 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2192 				  inode->i_ino);
2193 			nr_orphans++;
2194 		}
2195 		iput(inode);  /* The delete magic happens here! */
2196 	}
2197 
2198 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2199 
2200 	if (nr_orphans)
2201 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2202 		       PLURAL(nr_orphans));
2203 	if (nr_truncates)
2204 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2205 		       PLURAL(nr_truncates));
2206 #ifdef CONFIG_QUOTA
2207 	/* Turn quotas off */
2208 	for (i = 0; i < MAXQUOTAS; i++) {
2209 		if (sb_dqopt(sb)->files[i])
2210 			dquot_quota_off(sb, i);
2211 	}
2212 #endif
2213 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2214 }
2215 
2216 /*
2217  * Maximal extent format file size.
2218  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2219  * extent format containers, within a sector_t, and within i_blocks
2220  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2221  * so that won't be a limiting factor.
2222  *
2223  * However there is other limiting factor. We do store extents in the form
2224  * of starting block and length, hence the resulting length of the extent
2225  * covering maximum file size must fit into on-disk format containers as
2226  * well. Given that length is always by 1 unit bigger than max unit (because
2227  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2228  *
2229  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2230  */
2231 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2232 {
2233 	loff_t res;
2234 	loff_t upper_limit = MAX_LFS_FILESIZE;
2235 
2236 	/* small i_blocks in vfs inode? */
2237 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2238 		/*
2239 		 * CONFIG_LBDAF is not enabled implies the inode
2240 		 * i_block represent total blocks in 512 bytes
2241 		 * 32 == size of vfs inode i_blocks * 8
2242 		 */
2243 		upper_limit = (1LL << 32) - 1;
2244 
2245 		/* total blocks in file system block size */
2246 		upper_limit >>= (blkbits - 9);
2247 		upper_limit <<= blkbits;
2248 	}
2249 
2250 	/*
2251 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2252 	 * by one fs block, so ee_len can cover the extent of maximum file
2253 	 * size
2254 	 */
2255 	res = (1LL << 32) - 1;
2256 	res <<= blkbits;
2257 
2258 	/* Sanity check against vm- & vfs- imposed limits */
2259 	if (res > upper_limit)
2260 		res = upper_limit;
2261 
2262 	return res;
2263 }
2264 
2265 /*
2266  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2267  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2268  * We need to be 1 filesystem block less than the 2^48 sector limit.
2269  */
2270 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2271 {
2272 	loff_t res = EXT4_NDIR_BLOCKS;
2273 	int meta_blocks;
2274 	loff_t upper_limit;
2275 	/* This is calculated to be the largest file size for a dense, block
2276 	 * mapped file such that the file's total number of 512-byte sectors,
2277 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2278 	 *
2279 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2280 	 * number of 512-byte sectors of the file.
2281 	 */
2282 
2283 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2284 		/*
2285 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2286 		 * the inode i_block field represents total file blocks in
2287 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2288 		 */
2289 		upper_limit = (1LL << 32) - 1;
2290 
2291 		/* total blocks in file system block size */
2292 		upper_limit >>= (bits - 9);
2293 
2294 	} else {
2295 		/*
2296 		 * We use 48 bit ext4_inode i_blocks
2297 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2298 		 * represent total number of blocks in
2299 		 * file system block size
2300 		 */
2301 		upper_limit = (1LL << 48) - 1;
2302 
2303 	}
2304 
2305 	/* indirect blocks */
2306 	meta_blocks = 1;
2307 	/* double indirect blocks */
2308 	meta_blocks += 1 + (1LL << (bits-2));
2309 	/* tripple indirect blocks */
2310 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2311 
2312 	upper_limit -= meta_blocks;
2313 	upper_limit <<= bits;
2314 
2315 	res += 1LL << (bits-2);
2316 	res += 1LL << (2*(bits-2));
2317 	res += 1LL << (3*(bits-2));
2318 	res <<= bits;
2319 	if (res > upper_limit)
2320 		res = upper_limit;
2321 
2322 	if (res > MAX_LFS_FILESIZE)
2323 		res = MAX_LFS_FILESIZE;
2324 
2325 	return res;
2326 }
2327 
2328 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2329 				   ext4_fsblk_t logical_sb_block, int nr)
2330 {
2331 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2332 	ext4_group_t bg, first_meta_bg;
2333 	int has_super = 0;
2334 
2335 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2336 
2337 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2338 	    nr < first_meta_bg)
2339 		return logical_sb_block + nr + 1;
2340 	bg = sbi->s_desc_per_block * nr;
2341 	if (ext4_bg_has_super(sb, bg))
2342 		has_super = 1;
2343 
2344 	return (has_super + ext4_group_first_block_no(sb, bg));
2345 }
2346 
2347 /**
2348  * ext4_get_stripe_size: Get the stripe size.
2349  * @sbi: In memory super block info
2350  *
2351  * If we have specified it via mount option, then
2352  * use the mount option value. If the value specified at mount time is
2353  * greater than the blocks per group use the super block value.
2354  * If the super block value is greater than blocks per group return 0.
2355  * Allocator needs it be less than blocks per group.
2356  *
2357  */
2358 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2359 {
2360 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2361 	unsigned long stripe_width =
2362 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2363 	int ret;
2364 
2365 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2366 		ret = sbi->s_stripe;
2367 	else if (stripe_width <= sbi->s_blocks_per_group)
2368 		ret = stripe_width;
2369 	else if (stride <= sbi->s_blocks_per_group)
2370 		ret = stride;
2371 	else
2372 		ret = 0;
2373 
2374 	/*
2375 	 * If the stripe width is 1, this makes no sense and
2376 	 * we set it to 0 to turn off stripe handling code.
2377 	 */
2378 	if (ret <= 1)
2379 		ret = 0;
2380 
2381 	return ret;
2382 }
2383 
2384 /* sysfs supprt */
2385 
2386 struct ext4_attr {
2387 	struct attribute attr;
2388 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2389 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2390 			 const char *, size_t);
2391 	int offset;
2392 };
2393 
2394 static int parse_strtoul(const char *buf,
2395 		unsigned long max, unsigned long *value)
2396 {
2397 	char *endp;
2398 
2399 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2400 	endp = skip_spaces(endp);
2401 	if (*endp || *value > max)
2402 		return -EINVAL;
2403 
2404 	return 0;
2405 }
2406 
2407 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2408 					      struct ext4_sb_info *sbi,
2409 					      char *buf)
2410 {
2411 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2412 		(s64) EXT4_C2B(sbi,
2413 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2414 }
2415 
2416 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2417 					 struct ext4_sb_info *sbi, char *buf)
2418 {
2419 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2420 
2421 	if (!sb->s_bdev->bd_part)
2422 		return snprintf(buf, PAGE_SIZE, "0\n");
2423 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2424 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2425 			 sbi->s_sectors_written_start) >> 1);
2426 }
2427 
2428 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2429 					  struct ext4_sb_info *sbi, char *buf)
2430 {
2431 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2432 
2433 	if (!sb->s_bdev->bd_part)
2434 		return snprintf(buf, PAGE_SIZE, "0\n");
2435 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2436 			(unsigned long long)(sbi->s_kbytes_written +
2437 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2438 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2439 }
2440 
2441 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2442 					  struct ext4_sb_info *sbi,
2443 					  const char *buf, size_t count)
2444 {
2445 	unsigned long t;
2446 
2447 	if (parse_strtoul(buf, 0x40000000, &t))
2448 		return -EINVAL;
2449 
2450 	if (t && !is_power_of_2(t))
2451 		return -EINVAL;
2452 
2453 	sbi->s_inode_readahead_blks = t;
2454 	return count;
2455 }
2456 
2457 static ssize_t sbi_ui_show(struct ext4_attr *a,
2458 			   struct ext4_sb_info *sbi, char *buf)
2459 {
2460 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2461 
2462 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2463 }
2464 
2465 static ssize_t sbi_ui_store(struct ext4_attr *a,
2466 			    struct ext4_sb_info *sbi,
2467 			    const char *buf, size_t count)
2468 {
2469 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2470 	unsigned long t;
2471 
2472 	if (parse_strtoul(buf, 0xffffffff, &t))
2473 		return -EINVAL;
2474 	*ui = t;
2475 	return count;
2476 }
2477 
2478 static ssize_t trigger_test_error(struct ext4_attr *a,
2479 				  struct ext4_sb_info *sbi,
2480 				  const char *buf, size_t count)
2481 {
2482 	int len = count;
2483 
2484 	if (!capable(CAP_SYS_ADMIN))
2485 		return -EPERM;
2486 
2487 	if (len && buf[len-1] == '\n')
2488 		len--;
2489 
2490 	if (len)
2491 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2492 	return count;
2493 }
2494 
2495 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2496 static struct ext4_attr ext4_attr_##_name = {			\
2497 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2498 	.show	= _show,					\
2499 	.store	= _store,					\
2500 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2501 }
2502 #define EXT4_ATTR(name, mode, show, store) \
2503 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2504 
2505 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2506 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2507 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2508 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2509 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2510 #define ATTR_LIST(name) &ext4_attr_##name.attr
2511 
2512 EXT4_RO_ATTR(delayed_allocation_blocks);
2513 EXT4_RO_ATTR(session_write_kbytes);
2514 EXT4_RO_ATTR(lifetime_write_kbytes);
2515 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2516 		 inode_readahead_blks_store, s_inode_readahead_blks);
2517 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2518 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2519 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2520 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2521 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2522 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2523 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2524 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2525 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2526 
2527 static struct attribute *ext4_attrs[] = {
2528 	ATTR_LIST(delayed_allocation_blocks),
2529 	ATTR_LIST(session_write_kbytes),
2530 	ATTR_LIST(lifetime_write_kbytes),
2531 	ATTR_LIST(inode_readahead_blks),
2532 	ATTR_LIST(inode_goal),
2533 	ATTR_LIST(mb_stats),
2534 	ATTR_LIST(mb_max_to_scan),
2535 	ATTR_LIST(mb_min_to_scan),
2536 	ATTR_LIST(mb_order2_req),
2537 	ATTR_LIST(mb_stream_req),
2538 	ATTR_LIST(mb_group_prealloc),
2539 	ATTR_LIST(max_writeback_mb_bump),
2540 	ATTR_LIST(trigger_fs_error),
2541 	NULL,
2542 };
2543 
2544 /* Features this copy of ext4 supports */
2545 EXT4_INFO_ATTR(lazy_itable_init);
2546 EXT4_INFO_ATTR(batched_discard);
2547 
2548 static struct attribute *ext4_feat_attrs[] = {
2549 	ATTR_LIST(lazy_itable_init),
2550 	ATTR_LIST(batched_discard),
2551 	NULL,
2552 };
2553 
2554 static ssize_t ext4_attr_show(struct kobject *kobj,
2555 			      struct attribute *attr, char *buf)
2556 {
2557 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2558 						s_kobj);
2559 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2560 
2561 	return a->show ? a->show(a, sbi, buf) : 0;
2562 }
2563 
2564 static ssize_t ext4_attr_store(struct kobject *kobj,
2565 			       struct attribute *attr,
2566 			       const char *buf, size_t len)
2567 {
2568 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2569 						s_kobj);
2570 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2571 
2572 	return a->store ? a->store(a, sbi, buf, len) : 0;
2573 }
2574 
2575 static void ext4_sb_release(struct kobject *kobj)
2576 {
2577 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2578 						s_kobj);
2579 	complete(&sbi->s_kobj_unregister);
2580 }
2581 
2582 static const struct sysfs_ops ext4_attr_ops = {
2583 	.show	= ext4_attr_show,
2584 	.store	= ext4_attr_store,
2585 };
2586 
2587 static struct kobj_type ext4_ktype = {
2588 	.default_attrs	= ext4_attrs,
2589 	.sysfs_ops	= &ext4_attr_ops,
2590 	.release	= ext4_sb_release,
2591 };
2592 
2593 static void ext4_feat_release(struct kobject *kobj)
2594 {
2595 	complete(&ext4_feat->f_kobj_unregister);
2596 }
2597 
2598 static struct kobj_type ext4_feat_ktype = {
2599 	.default_attrs	= ext4_feat_attrs,
2600 	.sysfs_ops	= &ext4_attr_ops,
2601 	.release	= ext4_feat_release,
2602 };
2603 
2604 /*
2605  * Check whether this filesystem can be mounted based on
2606  * the features present and the RDONLY/RDWR mount requested.
2607  * Returns 1 if this filesystem can be mounted as requested,
2608  * 0 if it cannot be.
2609  */
2610 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2611 {
2612 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2613 		ext4_msg(sb, KERN_ERR,
2614 			"Couldn't mount because of "
2615 			"unsupported optional features (%x)",
2616 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2617 			~EXT4_FEATURE_INCOMPAT_SUPP));
2618 		return 0;
2619 	}
2620 
2621 	if (readonly)
2622 		return 1;
2623 
2624 	/* Check that feature set is OK for a read-write mount */
2625 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2626 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2627 			 "unsupported optional features (%x)",
2628 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2629 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2630 		return 0;
2631 	}
2632 	/*
2633 	 * Large file size enabled file system can only be mounted
2634 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2635 	 */
2636 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2637 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2638 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2639 				 "cannot be mounted RDWR without "
2640 				 "CONFIG_LBDAF");
2641 			return 0;
2642 		}
2643 	}
2644 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2645 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2646 		ext4_msg(sb, KERN_ERR,
2647 			 "Can't support bigalloc feature without "
2648 			 "extents feature\n");
2649 		return 0;
2650 	}
2651 
2652 #ifndef CONFIG_QUOTA
2653 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2654 	    !readonly) {
2655 		ext4_msg(sb, KERN_ERR,
2656 			 "Filesystem with quota feature cannot be mounted RDWR "
2657 			 "without CONFIG_QUOTA");
2658 		return 0;
2659 	}
2660 #endif  /* CONFIG_QUOTA */
2661 	return 1;
2662 }
2663 
2664 /*
2665  * This function is called once a day if we have errors logged
2666  * on the file system
2667  */
2668 static void print_daily_error_info(unsigned long arg)
2669 {
2670 	struct super_block *sb = (struct super_block *) arg;
2671 	struct ext4_sb_info *sbi;
2672 	struct ext4_super_block *es;
2673 
2674 	sbi = EXT4_SB(sb);
2675 	es = sbi->s_es;
2676 
2677 	if (es->s_error_count)
2678 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2679 			 le32_to_cpu(es->s_error_count));
2680 	if (es->s_first_error_time) {
2681 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2682 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2683 		       (int) sizeof(es->s_first_error_func),
2684 		       es->s_first_error_func,
2685 		       le32_to_cpu(es->s_first_error_line));
2686 		if (es->s_first_error_ino)
2687 			printk(": inode %u",
2688 			       le32_to_cpu(es->s_first_error_ino));
2689 		if (es->s_first_error_block)
2690 			printk(": block %llu", (unsigned long long)
2691 			       le64_to_cpu(es->s_first_error_block));
2692 		printk("\n");
2693 	}
2694 	if (es->s_last_error_time) {
2695 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2696 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2697 		       (int) sizeof(es->s_last_error_func),
2698 		       es->s_last_error_func,
2699 		       le32_to_cpu(es->s_last_error_line));
2700 		if (es->s_last_error_ino)
2701 			printk(": inode %u",
2702 			       le32_to_cpu(es->s_last_error_ino));
2703 		if (es->s_last_error_block)
2704 			printk(": block %llu", (unsigned long long)
2705 			       le64_to_cpu(es->s_last_error_block));
2706 		printk("\n");
2707 	}
2708 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2709 }
2710 
2711 /* Find next suitable group and run ext4_init_inode_table */
2712 static int ext4_run_li_request(struct ext4_li_request *elr)
2713 {
2714 	struct ext4_group_desc *gdp = NULL;
2715 	ext4_group_t group, ngroups;
2716 	struct super_block *sb;
2717 	unsigned long timeout = 0;
2718 	int ret = 0;
2719 
2720 	sb = elr->lr_super;
2721 	ngroups = EXT4_SB(sb)->s_groups_count;
2722 
2723 	sb_start_write(sb);
2724 	for (group = elr->lr_next_group; group < ngroups; group++) {
2725 		gdp = ext4_get_group_desc(sb, group, NULL);
2726 		if (!gdp) {
2727 			ret = 1;
2728 			break;
2729 		}
2730 
2731 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2732 			break;
2733 	}
2734 
2735 	if (group == ngroups)
2736 		ret = 1;
2737 
2738 	if (!ret) {
2739 		timeout = jiffies;
2740 		ret = ext4_init_inode_table(sb, group,
2741 					    elr->lr_timeout ? 0 : 1);
2742 		if (elr->lr_timeout == 0) {
2743 			timeout = (jiffies - timeout) *
2744 				  elr->lr_sbi->s_li_wait_mult;
2745 			elr->lr_timeout = timeout;
2746 		}
2747 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2748 		elr->lr_next_group = group + 1;
2749 	}
2750 	sb_end_write(sb);
2751 
2752 	return ret;
2753 }
2754 
2755 /*
2756  * Remove lr_request from the list_request and free the
2757  * request structure. Should be called with li_list_mtx held
2758  */
2759 static void ext4_remove_li_request(struct ext4_li_request *elr)
2760 {
2761 	struct ext4_sb_info *sbi;
2762 
2763 	if (!elr)
2764 		return;
2765 
2766 	sbi = elr->lr_sbi;
2767 
2768 	list_del(&elr->lr_request);
2769 	sbi->s_li_request = NULL;
2770 	kfree(elr);
2771 }
2772 
2773 static void ext4_unregister_li_request(struct super_block *sb)
2774 {
2775 	mutex_lock(&ext4_li_mtx);
2776 	if (!ext4_li_info) {
2777 		mutex_unlock(&ext4_li_mtx);
2778 		return;
2779 	}
2780 
2781 	mutex_lock(&ext4_li_info->li_list_mtx);
2782 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2783 	mutex_unlock(&ext4_li_info->li_list_mtx);
2784 	mutex_unlock(&ext4_li_mtx);
2785 }
2786 
2787 static struct task_struct *ext4_lazyinit_task;
2788 
2789 /*
2790  * This is the function where ext4lazyinit thread lives. It walks
2791  * through the request list searching for next scheduled filesystem.
2792  * When such a fs is found, run the lazy initialization request
2793  * (ext4_rn_li_request) and keep track of the time spend in this
2794  * function. Based on that time we compute next schedule time of
2795  * the request. When walking through the list is complete, compute
2796  * next waking time and put itself into sleep.
2797  */
2798 static int ext4_lazyinit_thread(void *arg)
2799 {
2800 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2801 	struct list_head *pos, *n;
2802 	struct ext4_li_request *elr;
2803 	unsigned long next_wakeup, cur;
2804 
2805 	BUG_ON(NULL == eli);
2806 
2807 cont_thread:
2808 	while (true) {
2809 		next_wakeup = MAX_JIFFY_OFFSET;
2810 
2811 		mutex_lock(&eli->li_list_mtx);
2812 		if (list_empty(&eli->li_request_list)) {
2813 			mutex_unlock(&eli->li_list_mtx);
2814 			goto exit_thread;
2815 		}
2816 
2817 		list_for_each_safe(pos, n, &eli->li_request_list) {
2818 			elr = list_entry(pos, struct ext4_li_request,
2819 					 lr_request);
2820 
2821 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2822 				if (ext4_run_li_request(elr) != 0) {
2823 					/* error, remove the lazy_init job */
2824 					ext4_remove_li_request(elr);
2825 					continue;
2826 				}
2827 			}
2828 
2829 			if (time_before(elr->lr_next_sched, next_wakeup))
2830 				next_wakeup = elr->lr_next_sched;
2831 		}
2832 		mutex_unlock(&eli->li_list_mtx);
2833 
2834 		try_to_freeze();
2835 
2836 		cur = jiffies;
2837 		if ((time_after_eq(cur, next_wakeup)) ||
2838 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2839 			cond_resched();
2840 			continue;
2841 		}
2842 
2843 		schedule_timeout_interruptible(next_wakeup - cur);
2844 
2845 		if (kthread_should_stop()) {
2846 			ext4_clear_request_list();
2847 			goto exit_thread;
2848 		}
2849 	}
2850 
2851 exit_thread:
2852 	/*
2853 	 * It looks like the request list is empty, but we need
2854 	 * to check it under the li_list_mtx lock, to prevent any
2855 	 * additions into it, and of course we should lock ext4_li_mtx
2856 	 * to atomically free the list and ext4_li_info, because at
2857 	 * this point another ext4 filesystem could be registering
2858 	 * new one.
2859 	 */
2860 	mutex_lock(&ext4_li_mtx);
2861 	mutex_lock(&eli->li_list_mtx);
2862 	if (!list_empty(&eli->li_request_list)) {
2863 		mutex_unlock(&eli->li_list_mtx);
2864 		mutex_unlock(&ext4_li_mtx);
2865 		goto cont_thread;
2866 	}
2867 	mutex_unlock(&eli->li_list_mtx);
2868 	kfree(ext4_li_info);
2869 	ext4_li_info = NULL;
2870 	mutex_unlock(&ext4_li_mtx);
2871 
2872 	return 0;
2873 }
2874 
2875 static void ext4_clear_request_list(void)
2876 {
2877 	struct list_head *pos, *n;
2878 	struct ext4_li_request *elr;
2879 
2880 	mutex_lock(&ext4_li_info->li_list_mtx);
2881 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2882 		elr = list_entry(pos, struct ext4_li_request,
2883 				 lr_request);
2884 		ext4_remove_li_request(elr);
2885 	}
2886 	mutex_unlock(&ext4_li_info->li_list_mtx);
2887 }
2888 
2889 static int ext4_run_lazyinit_thread(void)
2890 {
2891 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2892 					 ext4_li_info, "ext4lazyinit");
2893 	if (IS_ERR(ext4_lazyinit_task)) {
2894 		int err = PTR_ERR(ext4_lazyinit_task);
2895 		ext4_clear_request_list();
2896 		kfree(ext4_li_info);
2897 		ext4_li_info = NULL;
2898 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2899 				 "initialization thread\n",
2900 				 err);
2901 		return err;
2902 	}
2903 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2904 	return 0;
2905 }
2906 
2907 /*
2908  * Check whether it make sense to run itable init. thread or not.
2909  * If there is at least one uninitialized inode table, return
2910  * corresponding group number, else the loop goes through all
2911  * groups and return total number of groups.
2912  */
2913 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2914 {
2915 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2916 	struct ext4_group_desc *gdp = NULL;
2917 
2918 	for (group = 0; group < ngroups; group++) {
2919 		gdp = ext4_get_group_desc(sb, group, NULL);
2920 		if (!gdp)
2921 			continue;
2922 
2923 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2924 			break;
2925 	}
2926 
2927 	return group;
2928 }
2929 
2930 static int ext4_li_info_new(void)
2931 {
2932 	struct ext4_lazy_init *eli = NULL;
2933 
2934 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2935 	if (!eli)
2936 		return -ENOMEM;
2937 
2938 	INIT_LIST_HEAD(&eli->li_request_list);
2939 	mutex_init(&eli->li_list_mtx);
2940 
2941 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2942 
2943 	ext4_li_info = eli;
2944 
2945 	return 0;
2946 }
2947 
2948 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2949 					    ext4_group_t start)
2950 {
2951 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2952 	struct ext4_li_request *elr;
2953 	unsigned long rnd;
2954 
2955 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2956 	if (!elr)
2957 		return NULL;
2958 
2959 	elr->lr_super = sb;
2960 	elr->lr_sbi = sbi;
2961 	elr->lr_next_group = start;
2962 
2963 	/*
2964 	 * Randomize first schedule time of the request to
2965 	 * spread the inode table initialization requests
2966 	 * better.
2967 	 */
2968 	get_random_bytes(&rnd, sizeof(rnd));
2969 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
2970 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2971 
2972 	return elr;
2973 }
2974 
2975 static int ext4_register_li_request(struct super_block *sb,
2976 				    ext4_group_t first_not_zeroed)
2977 {
2978 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2979 	struct ext4_li_request *elr;
2980 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2981 	int ret = 0;
2982 
2983 	if (sbi->s_li_request != NULL) {
2984 		/*
2985 		 * Reset timeout so it can be computed again, because
2986 		 * s_li_wait_mult might have changed.
2987 		 */
2988 		sbi->s_li_request->lr_timeout = 0;
2989 		return 0;
2990 	}
2991 
2992 	if (first_not_zeroed == ngroups ||
2993 	    (sb->s_flags & MS_RDONLY) ||
2994 	    !test_opt(sb, INIT_INODE_TABLE))
2995 		return 0;
2996 
2997 	elr = ext4_li_request_new(sb, first_not_zeroed);
2998 	if (!elr)
2999 		return -ENOMEM;
3000 
3001 	mutex_lock(&ext4_li_mtx);
3002 
3003 	if (NULL == ext4_li_info) {
3004 		ret = ext4_li_info_new();
3005 		if (ret)
3006 			goto out;
3007 	}
3008 
3009 	mutex_lock(&ext4_li_info->li_list_mtx);
3010 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3011 	mutex_unlock(&ext4_li_info->li_list_mtx);
3012 
3013 	sbi->s_li_request = elr;
3014 	/*
3015 	 * set elr to NULL here since it has been inserted to
3016 	 * the request_list and the removal and free of it is
3017 	 * handled by ext4_clear_request_list from now on.
3018 	 */
3019 	elr = NULL;
3020 
3021 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3022 		ret = ext4_run_lazyinit_thread();
3023 		if (ret)
3024 			goto out;
3025 	}
3026 out:
3027 	mutex_unlock(&ext4_li_mtx);
3028 	if (ret)
3029 		kfree(elr);
3030 	return ret;
3031 }
3032 
3033 /*
3034  * We do not need to lock anything since this is called on
3035  * module unload.
3036  */
3037 static void ext4_destroy_lazyinit_thread(void)
3038 {
3039 	/*
3040 	 * If thread exited earlier
3041 	 * there's nothing to be done.
3042 	 */
3043 	if (!ext4_li_info || !ext4_lazyinit_task)
3044 		return;
3045 
3046 	kthread_stop(ext4_lazyinit_task);
3047 }
3048 
3049 static int set_journal_csum_feature_set(struct super_block *sb)
3050 {
3051 	int ret = 1;
3052 	int compat, incompat;
3053 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3054 
3055 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3056 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3057 		/* journal checksum v2 */
3058 		compat = 0;
3059 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3060 	} else {
3061 		/* journal checksum v1 */
3062 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3063 		incompat = 0;
3064 	}
3065 
3066 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3067 		ret = jbd2_journal_set_features(sbi->s_journal,
3068 				compat, 0,
3069 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3070 				incompat);
3071 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3072 		ret = jbd2_journal_set_features(sbi->s_journal,
3073 				compat, 0,
3074 				incompat);
3075 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3076 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3077 	} else {
3078 		jbd2_journal_clear_features(sbi->s_journal,
3079 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3080 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3081 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3082 	}
3083 
3084 	return ret;
3085 }
3086 
3087 /*
3088  * Note: calculating the overhead so we can be compatible with
3089  * historical BSD practice is quite difficult in the face of
3090  * clusters/bigalloc.  This is because multiple metadata blocks from
3091  * different block group can end up in the same allocation cluster.
3092  * Calculating the exact overhead in the face of clustered allocation
3093  * requires either O(all block bitmaps) in memory or O(number of block
3094  * groups**2) in time.  We will still calculate the superblock for
3095  * older file systems --- and if we come across with a bigalloc file
3096  * system with zero in s_overhead_clusters the estimate will be close to
3097  * correct especially for very large cluster sizes --- but for newer
3098  * file systems, it's better to calculate this figure once at mkfs
3099  * time, and store it in the superblock.  If the superblock value is
3100  * present (even for non-bigalloc file systems), we will use it.
3101  */
3102 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3103 			  char *buf)
3104 {
3105 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3106 	struct ext4_group_desc	*gdp;
3107 	ext4_fsblk_t		first_block, last_block, b;
3108 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3109 	int			s, j, count = 0;
3110 
3111 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3112 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3113 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3114 	for (i = 0; i < ngroups; i++) {
3115 		gdp = ext4_get_group_desc(sb, i, NULL);
3116 		b = ext4_block_bitmap(sb, gdp);
3117 		if (b >= first_block && b <= last_block) {
3118 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3119 			count++;
3120 		}
3121 		b = ext4_inode_bitmap(sb, gdp);
3122 		if (b >= first_block && b <= last_block) {
3123 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3124 			count++;
3125 		}
3126 		b = ext4_inode_table(sb, gdp);
3127 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3128 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3129 				int c = EXT4_B2C(sbi, b - first_block);
3130 				ext4_set_bit(c, buf);
3131 				count++;
3132 			}
3133 		if (i != grp)
3134 			continue;
3135 		s = 0;
3136 		if (ext4_bg_has_super(sb, grp)) {
3137 			ext4_set_bit(s++, buf);
3138 			count++;
3139 		}
3140 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3141 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3142 			count++;
3143 		}
3144 	}
3145 	if (!count)
3146 		return 0;
3147 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3148 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3149 }
3150 
3151 /*
3152  * Compute the overhead and stash it in sbi->s_overhead
3153  */
3154 int ext4_calculate_overhead(struct super_block *sb)
3155 {
3156 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3157 	struct ext4_super_block *es = sbi->s_es;
3158 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3159 	ext4_fsblk_t overhead = 0;
3160 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3161 
3162 	memset(buf, 0, PAGE_SIZE);
3163 	if (!buf)
3164 		return -ENOMEM;
3165 
3166 	/*
3167 	 * Compute the overhead (FS structures).  This is constant
3168 	 * for a given filesystem unless the number of block groups
3169 	 * changes so we cache the previous value until it does.
3170 	 */
3171 
3172 	/*
3173 	 * All of the blocks before first_data_block are overhead
3174 	 */
3175 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3176 
3177 	/*
3178 	 * Add the overhead found in each block group
3179 	 */
3180 	for (i = 0; i < ngroups; i++) {
3181 		int blks;
3182 
3183 		blks = count_overhead(sb, i, buf);
3184 		overhead += blks;
3185 		if (blks)
3186 			memset(buf, 0, PAGE_SIZE);
3187 		cond_resched();
3188 	}
3189 	sbi->s_overhead = overhead;
3190 	smp_wmb();
3191 	free_page((unsigned long) buf);
3192 	return 0;
3193 }
3194 
3195 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3196 {
3197 	char *orig_data = kstrdup(data, GFP_KERNEL);
3198 	struct buffer_head *bh;
3199 	struct ext4_super_block *es = NULL;
3200 	struct ext4_sb_info *sbi;
3201 	ext4_fsblk_t block;
3202 	ext4_fsblk_t sb_block = get_sb_block(&data);
3203 	ext4_fsblk_t logical_sb_block;
3204 	unsigned long offset = 0;
3205 	unsigned long journal_devnum = 0;
3206 	unsigned long def_mount_opts;
3207 	struct inode *root;
3208 	char *cp;
3209 	const char *descr;
3210 	int ret = -ENOMEM;
3211 	int blocksize, clustersize;
3212 	unsigned int db_count;
3213 	unsigned int i;
3214 	int needs_recovery, has_huge_files, has_bigalloc;
3215 	__u64 blocks_count;
3216 	int err;
3217 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3218 	ext4_group_t first_not_zeroed;
3219 
3220 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3221 	if (!sbi)
3222 		goto out_free_orig;
3223 
3224 	sbi->s_blockgroup_lock =
3225 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3226 	if (!sbi->s_blockgroup_lock) {
3227 		kfree(sbi);
3228 		goto out_free_orig;
3229 	}
3230 	sb->s_fs_info = sbi;
3231 	sbi->s_sb = sb;
3232 	sbi->s_mount_opt = 0;
3233 	sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
3234 	sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
3235 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3236 	sbi->s_sb_block = sb_block;
3237 	if (sb->s_bdev->bd_part)
3238 		sbi->s_sectors_written_start =
3239 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3240 
3241 	/* Cleanup superblock name */
3242 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3243 		*cp = '!';
3244 
3245 	ret = -EINVAL;
3246 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3247 	if (!blocksize) {
3248 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3249 		goto out_fail;
3250 	}
3251 
3252 	/*
3253 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3254 	 * block sizes.  We need to calculate the offset from buffer start.
3255 	 */
3256 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3257 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3258 		offset = do_div(logical_sb_block, blocksize);
3259 	} else {
3260 		logical_sb_block = sb_block;
3261 	}
3262 
3263 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3264 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3265 		goto out_fail;
3266 	}
3267 	/*
3268 	 * Note: s_es must be initialized as soon as possible because
3269 	 *       some ext4 macro-instructions depend on its value
3270 	 */
3271 	es = (struct ext4_super_block *) (bh->b_data + offset);
3272 	sbi->s_es = es;
3273 	sb->s_magic = le16_to_cpu(es->s_magic);
3274 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3275 		goto cantfind_ext4;
3276 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3277 
3278 	/* Warn if metadata_csum and gdt_csum are both set. */
3279 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3280 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3281 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3282 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3283 			     "redundant flags; please run fsck.");
3284 
3285 	/* Check for a known checksum algorithm */
3286 	if (!ext4_verify_csum_type(sb, es)) {
3287 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3288 			 "unknown checksum algorithm.");
3289 		silent = 1;
3290 		goto cantfind_ext4;
3291 	}
3292 
3293 	/* Load the checksum driver */
3294 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3295 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3296 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3297 		if (IS_ERR(sbi->s_chksum_driver)) {
3298 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3299 			ret = PTR_ERR(sbi->s_chksum_driver);
3300 			sbi->s_chksum_driver = NULL;
3301 			goto failed_mount;
3302 		}
3303 	}
3304 
3305 	/* Check superblock checksum */
3306 	if (!ext4_superblock_csum_verify(sb, es)) {
3307 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3308 			 "invalid superblock checksum.  Run e2fsck?");
3309 		silent = 1;
3310 		goto cantfind_ext4;
3311 	}
3312 
3313 	/* Precompute checksum seed for all metadata */
3314 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3315 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3316 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3317 					       sizeof(es->s_uuid));
3318 
3319 	/* Set defaults before we parse the mount options */
3320 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3321 	set_opt(sb, INIT_INODE_TABLE);
3322 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3323 		set_opt(sb, DEBUG);
3324 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3325 		set_opt(sb, GRPID);
3326 	if (def_mount_opts & EXT4_DEFM_UID16)
3327 		set_opt(sb, NO_UID32);
3328 	/* xattr user namespace & acls are now defaulted on */
3329 #ifdef CONFIG_EXT4_FS_XATTR
3330 	set_opt(sb, XATTR_USER);
3331 #endif
3332 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3333 	set_opt(sb, POSIX_ACL);
3334 #endif
3335 	set_opt(sb, MBLK_IO_SUBMIT);
3336 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3337 		set_opt(sb, JOURNAL_DATA);
3338 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3339 		set_opt(sb, ORDERED_DATA);
3340 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3341 		set_opt(sb, WRITEBACK_DATA);
3342 
3343 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3344 		set_opt(sb, ERRORS_PANIC);
3345 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3346 		set_opt(sb, ERRORS_CONT);
3347 	else
3348 		set_opt(sb, ERRORS_RO);
3349 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3350 		set_opt(sb, BLOCK_VALIDITY);
3351 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3352 		set_opt(sb, DISCARD);
3353 
3354 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3355 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3356 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3357 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3358 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3359 
3360 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3361 		set_opt(sb, BARRIER);
3362 
3363 	/*
3364 	 * enable delayed allocation by default
3365 	 * Use -o nodelalloc to turn it off
3366 	 */
3367 	if (!IS_EXT3_SB(sb) &&
3368 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3369 		set_opt(sb, DELALLOC);
3370 
3371 	/*
3372 	 * set default s_li_wait_mult for lazyinit, for the case there is
3373 	 * no mount option specified.
3374 	 */
3375 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3376 
3377 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3378 			   &journal_devnum, &journal_ioprio, 0)) {
3379 		ext4_msg(sb, KERN_WARNING,
3380 			 "failed to parse options in superblock: %s",
3381 			 sbi->s_es->s_mount_opts);
3382 	}
3383 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3384 	if (!parse_options((char *) data, sb, &journal_devnum,
3385 			   &journal_ioprio, 0))
3386 		goto failed_mount;
3387 
3388 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3389 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3390 			    "with data=journal disables delayed "
3391 			    "allocation and O_DIRECT support!\n");
3392 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3393 			ext4_msg(sb, KERN_ERR, "can't mount with "
3394 				 "both data=journal and delalloc");
3395 			goto failed_mount;
3396 		}
3397 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3398 			ext4_msg(sb, KERN_ERR, "can't mount with "
3399 				 "both data=journal and delalloc");
3400 			goto failed_mount;
3401 		}
3402 		if (test_opt(sb, DELALLOC))
3403 			clear_opt(sb, DELALLOC);
3404 	}
3405 
3406 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3407 	if (test_opt(sb, DIOREAD_NOLOCK)) {
3408 		if (blocksize < PAGE_SIZE) {
3409 			ext4_msg(sb, KERN_ERR, "can't mount with "
3410 				 "dioread_nolock if block size != PAGE_SIZE");
3411 			goto failed_mount;
3412 		}
3413 	}
3414 
3415 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3416 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3417 
3418 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3419 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3420 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3421 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3422 		ext4_msg(sb, KERN_WARNING,
3423 		       "feature flags set on rev 0 fs, "
3424 		       "running e2fsck is recommended");
3425 
3426 	if (IS_EXT2_SB(sb)) {
3427 		if (ext2_feature_set_ok(sb))
3428 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3429 				 "using the ext4 subsystem");
3430 		else {
3431 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3432 				 "to feature incompatibilities");
3433 			goto failed_mount;
3434 		}
3435 	}
3436 
3437 	if (IS_EXT3_SB(sb)) {
3438 		if (ext3_feature_set_ok(sb))
3439 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3440 				 "using the ext4 subsystem");
3441 		else {
3442 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3443 				 "to feature incompatibilities");
3444 			goto failed_mount;
3445 		}
3446 	}
3447 
3448 	/*
3449 	 * Check feature flags regardless of the revision level, since we
3450 	 * previously didn't change the revision level when setting the flags,
3451 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3452 	 */
3453 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3454 		goto failed_mount;
3455 
3456 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3457 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3458 		ext4_msg(sb, KERN_ERR,
3459 		       "Unsupported filesystem blocksize %d", blocksize);
3460 		goto failed_mount;
3461 	}
3462 
3463 	if (sb->s_blocksize != blocksize) {
3464 		/* Validate the filesystem blocksize */
3465 		if (!sb_set_blocksize(sb, blocksize)) {
3466 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3467 					blocksize);
3468 			goto failed_mount;
3469 		}
3470 
3471 		brelse(bh);
3472 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3473 		offset = do_div(logical_sb_block, blocksize);
3474 		bh = sb_bread(sb, logical_sb_block);
3475 		if (!bh) {
3476 			ext4_msg(sb, KERN_ERR,
3477 			       "Can't read superblock on 2nd try");
3478 			goto failed_mount;
3479 		}
3480 		es = (struct ext4_super_block *)(bh->b_data + offset);
3481 		sbi->s_es = es;
3482 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3483 			ext4_msg(sb, KERN_ERR,
3484 			       "Magic mismatch, very weird!");
3485 			goto failed_mount;
3486 		}
3487 	}
3488 
3489 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3490 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3491 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3492 						      has_huge_files);
3493 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3494 
3495 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3496 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3497 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3498 	} else {
3499 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3500 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3501 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3502 		    (!is_power_of_2(sbi->s_inode_size)) ||
3503 		    (sbi->s_inode_size > blocksize)) {
3504 			ext4_msg(sb, KERN_ERR,
3505 			       "unsupported inode size: %d",
3506 			       sbi->s_inode_size);
3507 			goto failed_mount;
3508 		}
3509 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3510 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3511 	}
3512 
3513 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3514 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3515 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3516 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3517 		    !is_power_of_2(sbi->s_desc_size)) {
3518 			ext4_msg(sb, KERN_ERR,
3519 			       "unsupported descriptor size %lu",
3520 			       sbi->s_desc_size);
3521 			goto failed_mount;
3522 		}
3523 	} else
3524 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3525 
3526 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3527 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3528 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3529 		goto cantfind_ext4;
3530 
3531 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3532 	if (sbi->s_inodes_per_block == 0)
3533 		goto cantfind_ext4;
3534 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3535 					sbi->s_inodes_per_block;
3536 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3537 	sbi->s_sbh = bh;
3538 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3539 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3540 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3541 
3542 	for (i = 0; i < 4; i++)
3543 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3544 	sbi->s_def_hash_version = es->s_def_hash_version;
3545 	i = le32_to_cpu(es->s_flags);
3546 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3547 		sbi->s_hash_unsigned = 3;
3548 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3549 #ifdef __CHAR_UNSIGNED__
3550 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3551 		sbi->s_hash_unsigned = 3;
3552 #else
3553 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3554 #endif
3555 	}
3556 
3557 	/* Handle clustersize */
3558 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3559 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3560 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3561 	if (has_bigalloc) {
3562 		if (clustersize < blocksize) {
3563 			ext4_msg(sb, KERN_ERR,
3564 				 "cluster size (%d) smaller than "
3565 				 "block size (%d)", clustersize, blocksize);
3566 			goto failed_mount;
3567 		}
3568 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3569 			le32_to_cpu(es->s_log_block_size);
3570 		sbi->s_clusters_per_group =
3571 			le32_to_cpu(es->s_clusters_per_group);
3572 		if (sbi->s_clusters_per_group > blocksize * 8) {
3573 			ext4_msg(sb, KERN_ERR,
3574 				 "#clusters per group too big: %lu",
3575 				 sbi->s_clusters_per_group);
3576 			goto failed_mount;
3577 		}
3578 		if (sbi->s_blocks_per_group !=
3579 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3580 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3581 				 "clusters per group (%lu) inconsistent",
3582 				 sbi->s_blocks_per_group,
3583 				 sbi->s_clusters_per_group);
3584 			goto failed_mount;
3585 		}
3586 	} else {
3587 		if (clustersize != blocksize) {
3588 			ext4_warning(sb, "fragment/cluster size (%d) != "
3589 				     "block size (%d)", clustersize,
3590 				     blocksize);
3591 			clustersize = blocksize;
3592 		}
3593 		if (sbi->s_blocks_per_group > blocksize * 8) {
3594 			ext4_msg(sb, KERN_ERR,
3595 				 "#blocks per group too big: %lu",
3596 				 sbi->s_blocks_per_group);
3597 			goto failed_mount;
3598 		}
3599 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3600 		sbi->s_cluster_bits = 0;
3601 	}
3602 	sbi->s_cluster_ratio = clustersize / blocksize;
3603 
3604 	if (sbi->s_inodes_per_group > blocksize * 8) {
3605 		ext4_msg(sb, KERN_ERR,
3606 		       "#inodes per group too big: %lu",
3607 		       sbi->s_inodes_per_group);
3608 		goto failed_mount;
3609 	}
3610 
3611 	/*
3612 	 * Test whether we have more sectors than will fit in sector_t,
3613 	 * and whether the max offset is addressable by the page cache.
3614 	 */
3615 	err = generic_check_addressable(sb->s_blocksize_bits,
3616 					ext4_blocks_count(es));
3617 	if (err) {
3618 		ext4_msg(sb, KERN_ERR, "filesystem"
3619 			 " too large to mount safely on this system");
3620 		if (sizeof(sector_t) < 8)
3621 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3622 		ret = err;
3623 		goto failed_mount;
3624 	}
3625 
3626 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3627 		goto cantfind_ext4;
3628 
3629 	/* check blocks count against device size */
3630 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3631 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3632 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3633 		       "exceeds size of device (%llu blocks)",
3634 		       ext4_blocks_count(es), blocks_count);
3635 		goto failed_mount;
3636 	}
3637 
3638 	/*
3639 	 * It makes no sense for the first data block to be beyond the end
3640 	 * of the filesystem.
3641 	 */
3642 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3643 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3644 			 "block %u is beyond end of filesystem (%llu)",
3645 			 le32_to_cpu(es->s_first_data_block),
3646 			 ext4_blocks_count(es));
3647 		goto failed_mount;
3648 	}
3649 	blocks_count = (ext4_blocks_count(es) -
3650 			le32_to_cpu(es->s_first_data_block) +
3651 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3652 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3653 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3654 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3655 		       "(block count %llu, first data block %u, "
3656 		       "blocks per group %lu)", sbi->s_groups_count,
3657 		       ext4_blocks_count(es),
3658 		       le32_to_cpu(es->s_first_data_block),
3659 		       EXT4_BLOCKS_PER_GROUP(sb));
3660 		goto failed_mount;
3661 	}
3662 	sbi->s_groups_count = blocks_count;
3663 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3664 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3665 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3666 		   EXT4_DESC_PER_BLOCK(sb);
3667 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3668 					  sizeof(struct buffer_head *),
3669 					  GFP_KERNEL);
3670 	if (sbi->s_group_desc == NULL) {
3671 		ext4_msg(sb, KERN_ERR, "not enough memory");
3672 		ret = -ENOMEM;
3673 		goto failed_mount;
3674 	}
3675 
3676 	if (ext4_proc_root)
3677 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3678 
3679 	if (sbi->s_proc)
3680 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3681 				 &ext4_seq_options_fops, sb);
3682 
3683 	bgl_lock_init(sbi->s_blockgroup_lock);
3684 
3685 	for (i = 0; i < db_count; i++) {
3686 		block = descriptor_loc(sb, logical_sb_block, i);
3687 		sbi->s_group_desc[i] = sb_bread(sb, block);
3688 		if (!sbi->s_group_desc[i]) {
3689 			ext4_msg(sb, KERN_ERR,
3690 			       "can't read group descriptor %d", i);
3691 			db_count = i;
3692 			goto failed_mount2;
3693 		}
3694 	}
3695 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3696 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3697 		goto failed_mount2;
3698 	}
3699 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3700 		if (!ext4_fill_flex_info(sb)) {
3701 			ext4_msg(sb, KERN_ERR,
3702 			       "unable to initialize "
3703 			       "flex_bg meta info!");
3704 			goto failed_mount2;
3705 		}
3706 
3707 	sbi->s_gdb_count = db_count;
3708 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3709 	spin_lock_init(&sbi->s_next_gen_lock);
3710 
3711 	init_timer(&sbi->s_err_report);
3712 	sbi->s_err_report.function = print_daily_error_info;
3713 	sbi->s_err_report.data = (unsigned long) sb;
3714 
3715 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3716 			ext4_count_free_clusters(sb));
3717 	if (!err) {
3718 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3719 				ext4_count_free_inodes(sb));
3720 	}
3721 	if (!err) {
3722 		err = percpu_counter_init(&sbi->s_dirs_counter,
3723 				ext4_count_dirs(sb));
3724 	}
3725 	if (!err) {
3726 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3727 	}
3728 	if (err) {
3729 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3730 		ret = err;
3731 		goto failed_mount3;
3732 	}
3733 
3734 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3735 	sbi->s_max_writeback_mb_bump = 128;
3736 
3737 	/*
3738 	 * set up enough so that it can read an inode
3739 	 */
3740 	if (!test_opt(sb, NOLOAD) &&
3741 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3742 		sb->s_op = &ext4_sops;
3743 	else
3744 		sb->s_op = &ext4_nojournal_sops;
3745 	sb->s_export_op = &ext4_export_ops;
3746 	sb->s_xattr = ext4_xattr_handlers;
3747 #ifdef CONFIG_QUOTA
3748 	sb->s_qcop = &ext4_qctl_operations;
3749 	sb->dq_op = &ext4_quota_operations;
3750 
3751 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
3752 		/* Use qctl operations for hidden quota files. */
3753 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3754 	}
3755 #endif
3756 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3757 
3758 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3759 	mutex_init(&sbi->s_orphan_lock);
3760 	sbi->s_resize_flags = 0;
3761 
3762 	sb->s_root = NULL;
3763 
3764 	needs_recovery = (es->s_last_orphan != 0 ||
3765 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3766 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3767 
3768 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3769 	    !(sb->s_flags & MS_RDONLY))
3770 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3771 			goto failed_mount3;
3772 
3773 	/*
3774 	 * The first inode we look at is the journal inode.  Don't try
3775 	 * root first: it may be modified in the journal!
3776 	 */
3777 	if (!test_opt(sb, NOLOAD) &&
3778 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3779 		if (ext4_load_journal(sb, es, journal_devnum))
3780 			goto failed_mount3;
3781 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3782 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3783 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3784 		       "suppressed and not mounted read-only");
3785 		goto failed_mount_wq;
3786 	} else {
3787 		clear_opt(sb, DATA_FLAGS);
3788 		sbi->s_journal = NULL;
3789 		needs_recovery = 0;
3790 		goto no_journal;
3791 	}
3792 
3793 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3794 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3795 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3796 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3797 		goto failed_mount_wq;
3798 	}
3799 
3800 	if (!set_journal_csum_feature_set(sb)) {
3801 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3802 			 "feature set");
3803 		goto failed_mount_wq;
3804 	}
3805 
3806 	/* We have now updated the journal if required, so we can
3807 	 * validate the data journaling mode. */
3808 	switch (test_opt(sb, DATA_FLAGS)) {
3809 	case 0:
3810 		/* No mode set, assume a default based on the journal
3811 		 * capabilities: ORDERED_DATA if the journal can
3812 		 * cope, else JOURNAL_DATA
3813 		 */
3814 		if (jbd2_journal_check_available_features
3815 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3816 			set_opt(sb, ORDERED_DATA);
3817 		else
3818 			set_opt(sb, JOURNAL_DATA);
3819 		break;
3820 
3821 	case EXT4_MOUNT_ORDERED_DATA:
3822 	case EXT4_MOUNT_WRITEBACK_DATA:
3823 		if (!jbd2_journal_check_available_features
3824 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3825 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3826 			       "requested data journaling mode");
3827 			goto failed_mount_wq;
3828 		}
3829 	default:
3830 		break;
3831 	}
3832 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3833 
3834 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3835 
3836 	/*
3837 	 * The journal may have updated the bg summary counts, so we
3838 	 * need to update the global counters.
3839 	 */
3840 	percpu_counter_set(&sbi->s_freeclusters_counter,
3841 			   ext4_count_free_clusters(sb));
3842 	percpu_counter_set(&sbi->s_freeinodes_counter,
3843 			   ext4_count_free_inodes(sb));
3844 	percpu_counter_set(&sbi->s_dirs_counter,
3845 			   ext4_count_dirs(sb));
3846 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3847 
3848 no_journal:
3849 	/*
3850 	 * Get the # of file system overhead blocks from the
3851 	 * superblock if present.
3852 	 */
3853 	if (es->s_overhead_clusters)
3854 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3855 	else {
3856 		ret = ext4_calculate_overhead(sb);
3857 		if (ret)
3858 			goto failed_mount_wq;
3859 	}
3860 
3861 	/*
3862 	 * The maximum number of concurrent works can be high and
3863 	 * concurrency isn't really necessary.  Limit it to 1.
3864 	 */
3865 	EXT4_SB(sb)->dio_unwritten_wq =
3866 		alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3867 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3868 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3869 		goto failed_mount_wq;
3870 	}
3871 
3872 	/*
3873 	 * The jbd2_journal_load will have done any necessary log recovery,
3874 	 * so we can safely mount the rest of the filesystem now.
3875 	 */
3876 
3877 	root = ext4_iget(sb, EXT4_ROOT_INO);
3878 	if (IS_ERR(root)) {
3879 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3880 		ret = PTR_ERR(root);
3881 		root = NULL;
3882 		goto failed_mount4;
3883 	}
3884 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3885 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3886 		iput(root);
3887 		goto failed_mount4;
3888 	}
3889 	sb->s_root = d_make_root(root);
3890 	if (!sb->s_root) {
3891 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3892 		ret = -ENOMEM;
3893 		goto failed_mount4;
3894 	}
3895 
3896 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3897 		sb->s_flags |= MS_RDONLY;
3898 
3899 	/* determine the minimum size of new large inodes, if present */
3900 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3901 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3902 						     EXT4_GOOD_OLD_INODE_SIZE;
3903 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3904 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3905 			if (sbi->s_want_extra_isize <
3906 			    le16_to_cpu(es->s_want_extra_isize))
3907 				sbi->s_want_extra_isize =
3908 					le16_to_cpu(es->s_want_extra_isize);
3909 			if (sbi->s_want_extra_isize <
3910 			    le16_to_cpu(es->s_min_extra_isize))
3911 				sbi->s_want_extra_isize =
3912 					le16_to_cpu(es->s_min_extra_isize);
3913 		}
3914 	}
3915 	/* Check if enough inode space is available */
3916 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3917 							sbi->s_inode_size) {
3918 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3919 						       EXT4_GOOD_OLD_INODE_SIZE;
3920 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3921 			 "available");
3922 	}
3923 
3924 	err = ext4_setup_system_zone(sb);
3925 	if (err) {
3926 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3927 			 "zone (%d)", err);
3928 		goto failed_mount4a;
3929 	}
3930 
3931 	ext4_ext_init(sb);
3932 	err = ext4_mb_init(sb);
3933 	if (err) {
3934 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3935 			 err);
3936 		goto failed_mount5;
3937 	}
3938 
3939 	err = ext4_register_li_request(sb, first_not_zeroed);
3940 	if (err)
3941 		goto failed_mount6;
3942 
3943 	sbi->s_kobj.kset = ext4_kset;
3944 	init_completion(&sbi->s_kobj_unregister);
3945 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3946 				   "%s", sb->s_id);
3947 	if (err)
3948 		goto failed_mount7;
3949 
3950 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3951 	ext4_orphan_cleanup(sb, es);
3952 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3953 	if (needs_recovery) {
3954 		ext4_msg(sb, KERN_INFO, "recovery complete");
3955 		ext4_mark_recovery_complete(sb, es);
3956 	}
3957 	if (EXT4_SB(sb)->s_journal) {
3958 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3959 			descr = " journalled data mode";
3960 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3961 			descr = " ordered data mode";
3962 		else
3963 			descr = " writeback data mode";
3964 	} else
3965 		descr = "out journal";
3966 
3967 #ifdef CONFIG_QUOTA
3968 	/* Enable quota usage during mount. */
3969 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
3970 	    !(sb->s_flags & MS_RDONLY)) {
3971 		ret = ext4_enable_quotas(sb);
3972 		if (ret)
3973 			goto failed_mount7;
3974 	}
3975 #endif  /* CONFIG_QUOTA */
3976 
3977 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3978 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3979 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3980 
3981 	if (es->s_error_count)
3982 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3983 
3984 	kfree(orig_data);
3985 	return 0;
3986 
3987 cantfind_ext4:
3988 	if (!silent)
3989 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3990 	goto failed_mount;
3991 
3992 failed_mount7:
3993 	ext4_unregister_li_request(sb);
3994 failed_mount6:
3995 	ext4_mb_release(sb);
3996 failed_mount5:
3997 	ext4_ext_release(sb);
3998 	ext4_release_system_zone(sb);
3999 failed_mount4a:
4000 	dput(sb->s_root);
4001 	sb->s_root = NULL;
4002 failed_mount4:
4003 	ext4_msg(sb, KERN_ERR, "mount failed");
4004 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4005 failed_mount_wq:
4006 	if (sbi->s_journal) {
4007 		jbd2_journal_destroy(sbi->s_journal);
4008 		sbi->s_journal = NULL;
4009 	}
4010 failed_mount3:
4011 	del_timer(&sbi->s_err_report);
4012 	if (sbi->s_flex_groups)
4013 		ext4_kvfree(sbi->s_flex_groups);
4014 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4015 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4016 	percpu_counter_destroy(&sbi->s_dirs_counter);
4017 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4018 	if (sbi->s_mmp_tsk)
4019 		kthread_stop(sbi->s_mmp_tsk);
4020 failed_mount2:
4021 	for (i = 0; i < db_count; i++)
4022 		brelse(sbi->s_group_desc[i]);
4023 	ext4_kvfree(sbi->s_group_desc);
4024 failed_mount:
4025 	if (sbi->s_chksum_driver)
4026 		crypto_free_shash(sbi->s_chksum_driver);
4027 	if (sbi->s_proc) {
4028 		remove_proc_entry("options", sbi->s_proc);
4029 		remove_proc_entry(sb->s_id, ext4_proc_root);
4030 	}
4031 #ifdef CONFIG_QUOTA
4032 	for (i = 0; i < MAXQUOTAS; i++)
4033 		kfree(sbi->s_qf_names[i]);
4034 #endif
4035 	ext4_blkdev_remove(sbi);
4036 	brelse(bh);
4037 out_fail:
4038 	sb->s_fs_info = NULL;
4039 	kfree(sbi->s_blockgroup_lock);
4040 	kfree(sbi);
4041 out_free_orig:
4042 	kfree(orig_data);
4043 	return ret;
4044 }
4045 
4046 /*
4047  * Setup any per-fs journal parameters now.  We'll do this both on
4048  * initial mount, once the journal has been initialised but before we've
4049  * done any recovery; and again on any subsequent remount.
4050  */
4051 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4052 {
4053 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4054 
4055 	journal->j_commit_interval = sbi->s_commit_interval;
4056 	journal->j_min_batch_time = sbi->s_min_batch_time;
4057 	journal->j_max_batch_time = sbi->s_max_batch_time;
4058 
4059 	write_lock(&journal->j_state_lock);
4060 	if (test_opt(sb, BARRIER))
4061 		journal->j_flags |= JBD2_BARRIER;
4062 	else
4063 		journal->j_flags &= ~JBD2_BARRIER;
4064 	if (test_opt(sb, DATA_ERR_ABORT))
4065 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4066 	else
4067 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4068 	write_unlock(&journal->j_state_lock);
4069 }
4070 
4071 static journal_t *ext4_get_journal(struct super_block *sb,
4072 				   unsigned int journal_inum)
4073 {
4074 	struct inode *journal_inode;
4075 	journal_t *journal;
4076 
4077 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4078 
4079 	/* First, test for the existence of a valid inode on disk.  Bad
4080 	 * things happen if we iget() an unused inode, as the subsequent
4081 	 * iput() will try to delete it. */
4082 
4083 	journal_inode = ext4_iget(sb, journal_inum);
4084 	if (IS_ERR(journal_inode)) {
4085 		ext4_msg(sb, KERN_ERR, "no journal found");
4086 		return NULL;
4087 	}
4088 	if (!journal_inode->i_nlink) {
4089 		make_bad_inode(journal_inode);
4090 		iput(journal_inode);
4091 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4092 		return NULL;
4093 	}
4094 
4095 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4096 		  journal_inode, journal_inode->i_size);
4097 	if (!S_ISREG(journal_inode->i_mode)) {
4098 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4099 		iput(journal_inode);
4100 		return NULL;
4101 	}
4102 
4103 	journal = jbd2_journal_init_inode(journal_inode);
4104 	if (!journal) {
4105 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4106 		iput(journal_inode);
4107 		return NULL;
4108 	}
4109 	journal->j_private = sb;
4110 	ext4_init_journal_params(sb, journal);
4111 	return journal;
4112 }
4113 
4114 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4115 				       dev_t j_dev)
4116 {
4117 	struct buffer_head *bh;
4118 	journal_t *journal;
4119 	ext4_fsblk_t start;
4120 	ext4_fsblk_t len;
4121 	int hblock, blocksize;
4122 	ext4_fsblk_t sb_block;
4123 	unsigned long offset;
4124 	struct ext4_super_block *es;
4125 	struct block_device *bdev;
4126 
4127 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4128 
4129 	bdev = ext4_blkdev_get(j_dev, sb);
4130 	if (bdev == NULL)
4131 		return NULL;
4132 
4133 	blocksize = sb->s_blocksize;
4134 	hblock = bdev_logical_block_size(bdev);
4135 	if (blocksize < hblock) {
4136 		ext4_msg(sb, KERN_ERR,
4137 			"blocksize too small for journal device");
4138 		goto out_bdev;
4139 	}
4140 
4141 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4142 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4143 	set_blocksize(bdev, blocksize);
4144 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4145 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4146 		       "external journal");
4147 		goto out_bdev;
4148 	}
4149 
4150 	es = (struct ext4_super_block *) (bh->b_data + offset);
4151 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4152 	    !(le32_to_cpu(es->s_feature_incompat) &
4153 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4154 		ext4_msg(sb, KERN_ERR, "external journal has "
4155 					"bad superblock");
4156 		brelse(bh);
4157 		goto out_bdev;
4158 	}
4159 
4160 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4161 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4162 		brelse(bh);
4163 		goto out_bdev;
4164 	}
4165 
4166 	len = ext4_blocks_count(es);
4167 	start = sb_block + 1;
4168 	brelse(bh);	/* we're done with the superblock */
4169 
4170 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4171 					start, len, blocksize);
4172 	if (!journal) {
4173 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4174 		goto out_bdev;
4175 	}
4176 	journal->j_private = sb;
4177 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
4178 	wait_on_buffer(journal->j_sb_buffer);
4179 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4180 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4181 		goto out_journal;
4182 	}
4183 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4184 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4185 					"user (unsupported) - %d",
4186 			be32_to_cpu(journal->j_superblock->s_nr_users));
4187 		goto out_journal;
4188 	}
4189 	EXT4_SB(sb)->journal_bdev = bdev;
4190 	ext4_init_journal_params(sb, journal);
4191 	return journal;
4192 
4193 out_journal:
4194 	jbd2_journal_destroy(journal);
4195 out_bdev:
4196 	ext4_blkdev_put(bdev);
4197 	return NULL;
4198 }
4199 
4200 static int ext4_load_journal(struct super_block *sb,
4201 			     struct ext4_super_block *es,
4202 			     unsigned long journal_devnum)
4203 {
4204 	journal_t *journal;
4205 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4206 	dev_t journal_dev;
4207 	int err = 0;
4208 	int really_read_only;
4209 
4210 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4211 
4212 	if (journal_devnum &&
4213 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4214 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4215 			"numbers have changed");
4216 		journal_dev = new_decode_dev(journal_devnum);
4217 	} else
4218 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4219 
4220 	really_read_only = bdev_read_only(sb->s_bdev);
4221 
4222 	/*
4223 	 * Are we loading a blank journal or performing recovery after a
4224 	 * crash?  For recovery, we need to check in advance whether we
4225 	 * can get read-write access to the device.
4226 	 */
4227 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4228 		if (sb->s_flags & MS_RDONLY) {
4229 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4230 					"required on readonly filesystem");
4231 			if (really_read_only) {
4232 				ext4_msg(sb, KERN_ERR, "write access "
4233 					"unavailable, cannot proceed");
4234 				return -EROFS;
4235 			}
4236 			ext4_msg(sb, KERN_INFO, "write access will "
4237 			       "be enabled during recovery");
4238 		}
4239 	}
4240 
4241 	if (journal_inum && journal_dev) {
4242 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4243 		       "and inode journals!");
4244 		return -EINVAL;
4245 	}
4246 
4247 	if (journal_inum) {
4248 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4249 			return -EINVAL;
4250 	} else {
4251 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4252 			return -EINVAL;
4253 	}
4254 
4255 	if (!(journal->j_flags & JBD2_BARRIER))
4256 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4257 
4258 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4259 		err = jbd2_journal_wipe(journal, !really_read_only);
4260 	if (!err) {
4261 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4262 		if (save)
4263 			memcpy(save, ((char *) es) +
4264 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4265 		err = jbd2_journal_load(journal);
4266 		if (save)
4267 			memcpy(((char *) es) + EXT4_S_ERR_START,
4268 			       save, EXT4_S_ERR_LEN);
4269 		kfree(save);
4270 	}
4271 
4272 	if (err) {
4273 		ext4_msg(sb, KERN_ERR, "error loading journal");
4274 		jbd2_journal_destroy(journal);
4275 		return err;
4276 	}
4277 
4278 	EXT4_SB(sb)->s_journal = journal;
4279 	ext4_clear_journal_err(sb, es);
4280 
4281 	if (!really_read_only && journal_devnum &&
4282 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4283 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4284 
4285 		/* Make sure we flush the recovery flag to disk. */
4286 		ext4_commit_super(sb, 1);
4287 	}
4288 
4289 	return 0;
4290 }
4291 
4292 static int ext4_commit_super(struct super_block *sb, int sync)
4293 {
4294 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4295 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4296 	int error = 0;
4297 
4298 	if (!sbh || block_device_ejected(sb))
4299 		return error;
4300 	if (buffer_write_io_error(sbh)) {
4301 		/*
4302 		 * Oh, dear.  A previous attempt to write the
4303 		 * superblock failed.  This could happen because the
4304 		 * USB device was yanked out.  Or it could happen to
4305 		 * be a transient write error and maybe the block will
4306 		 * be remapped.  Nothing we can do but to retry the
4307 		 * write and hope for the best.
4308 		 */
4309 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4310 		       "superblock detected");
4311 		clear_buffer_write_io_error(sbh);
4312 		set_buffer_uptodate(sbh);
4313 	}
4314 	/*
4315 	 * If the file system is mounted read-only, don't update the
4316 	 * superblock write time.  This avoids updating the superblock
4317 	 * write time when we are mounting the root file system
4318 	 * read/only but we need to replay the journal; at that point,
4319 	 * for people who are east of GMT and who make their clock
4320 	 * tick in localtime for Windows bug-for-bug compatibility,
4321 	 * the clock is set in the future, and this will cause e2fsck
4322 	 * to complain and force a full file system check.
4323 	 */
4324 	if (!(sb->s_flags & MS_RDONLY))
4325 		es->s_wtime = cpu_to_le32(get_seconds());
4326 	if (sb->s_bdev->bd_part)
4327 		es->s_kbytes_written =
4328 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4329 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4330 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4331 	else
4332 		es->s_kbytes_written =
4333 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4334 	ext4_free_blocks_count_set(es,
4335 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4336 				&EXT4_SB(sb)->s_freeclusters_counter)));
4337 	es->s_free_inodes_count =
4338 		cpu_to_le32(percpu_counter_sum_positive(
4339 				&EXT4_SB(sb)->s_freeinodes_counter));
4340 	BUFFER_TRACE(sbh, "marking dirty");
4341 	ext4_superblock_csum_set(sb, es);
4342 	mark_buffer_dirty(sbh);
4343 	if (sync) {
4344 		error = sync_dirty_buffer(sbh);
4345 		if (error)
4346 			return error;
4347 
4348 		error = buffer_write_io_error(sbh);
4349 		if (error) {
4350 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4351 			       "superblock");
4352 			clear_buffer_write_io_error(sbh);
4353 			set_buffer_uptodate(sbh);
4354 		}
4355 	}
4356 	return error;
4357 }
4358 
4359 /*
4360  * Have we just finished recovery?  If so, and if we are mounting (or
4361  * remounting) the filesystem readonly, then we will end up with a
4362  * consistent fs on disk.  Record that fact.
4363  */
4364 static void ext4_mark_recovery_complete(struct super_block *sb,
4365 					struct ext4_super_block *es)
4366 {
4367 	journal_t *journal = EXT4_SB(sb)->s_journal;
4368 
4369 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4370 		BUG_ON(journal != NULL);
4371 		return;
4372 	}
4373 	jbd2_journal_lock_updates(journal);
4374 	if (jbd2_journal_flush(journal) < 0)
4375 		goto out;
4376 
4377 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4378 	    sb->s_flags & MS_RDONLY) {
4379 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4380 		ext4_commit_super(sb, 1);
4381 	}
4382 
4383 out:
4384 	jbd2_journal_unlock_updates(journal);
4385 }
4386 
4387 /*
4388  * If we are mounting (or read-write remounting) a filesystem whose journal
4389  * has recorded an error from a previous lifetime, move that error to the
4390  * main filesystem now.
4391  */
4392 static void ext4_clear_journal_err(struct super_block *sb,
4393 				   struct ext4_super_block *es)
4394 {
4395 	journal_t *journal;
4396 	int j_errno;
4397 	const char *errstr;
4398 
4399 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4400 
4401 	journal = EXT4_SB(sb)->s_journal;
4402 
4403 	/*
4404 	 * Now check for any error status which may have been recorded in the
4405 	 * journal by a prior ext4_error() or ext4_abort()
4406 	 */
4407 
4408 	j_errno = jbd2_journal_errno(journal);
4409 	if (j_errno) {
4410 		char nbuf[16];
4411 
4412 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4413 		ext4_warning(sb, "Filesystem error recorded "
4414 			     "from previous mount: %s", errstr);
4415 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4416 
4417 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4418 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4419 		ext4_commit_super(sb, 1);
4420 
4421 		jbd2_journal_clear_err(journal);
4422 	}
4423 }
4424 
4425 /*
4426  * Force the running and committing transactions to commit,
4427  * and wait on the commit.
4428  */
4429 int ext4_force_commit(struct super_block *sb)
4430 {
4431 	journal_t *journal;
4432 	int ret = 0;
4433 
4434 	if (sb->s_flags & MS_RDONLY)
4435 		return 0;
4436 
4437 	journal = EXT4_SB(sb)->s_journal;
4438 	if (journal)
4439 		ret = ext4_journal_force_commit(journal);
4440 
4441 	return ret;
4442 }
4443 
4444 static int ext4_sync_fs(struct super_block *sb, int wait)
4445 {
4446 	int ret = 0;
4447 	tid_t target;
4448 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4449 
4450 	trace_ext4_sync_fs(sb, wait);
4451 	flush_workqueue(sbi->dio_unwritten_wq);
4452 	/*
4453 	 * Writeback quota in non-journalled quota case - journalled quota has
4454 	 * no dirty dquots
4455 	 */
4456 	dquot_writeback_dquots(sb, -1);
4457 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4458 		if (wait)
4459 			jbd2_log_wait_commit(sbi->s_journal, target);
4460 	}
4461 	return ret;
4462 }
4463 
4464 /*
4465  * LVM calls this function before a (read-only) snapshot is created.  This
4466  * gives us a chance to flush the journal completely and mark the fs clean.
4467  *
4468  * Note that only this function cannot bring a filesystem to be in a clean
4469  * state independently. It relies on upper layer to stop all data & metadata
4470  * modifications.
4471  */
4472 static int ext4_freeze(struct super_block *sb)
4473 {
4474 	int error = 0;
4475 	journal_t *journal;
4476 
4477 	if (sb->s_flags & MS_RDONLY)
4478 		return 0;
4479 
4480 	journal = EXT4_SB(sb)->s_journal;
4481 
4482 	/* Now we set up the journal barrier. */
4483 	jbd2_journal_lock_updates(journal);
4484 
4485 	/*
4486 	 * Don't clear the needs_recovery flag if we failed to flush
4487 	 * the journal.
4488 	 */
4489 	error = jbd2_journal_flush(journal);
4490 	if (error < 0)
4491 		goto out;
4492 
4493 	/* Journal blocked and flushed, clear needs_recovery flag. */
4494 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4495 	error = ext4_commit_super(sb, 1);
4496 out:
4497 	/* we rely on upper layer to stop further updates */
4498 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4499 	return error;
4500 }
4501 
4502 /*
4503  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4504  * flag here, even though the filesystem is not technically dirty yet.
4505  */
4506 static int ext4_unfreeze(struct super_block *sb)
4507 {
4508 	if (sb->s_flags & MS_RDONLY)
4509 		return 0;
4510 
4511 	lock_super(sb);
4512 	/* Reset the needs_recovery flag before the fs is unlocked. */
4513 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4514 	ext4_commit_super(sb, 1);
4515 	unlock_super(sb);
4516 	return 0;
4517 }
4518 
4519 /*
4520  * Structure to save mount options for ext4_remount's benefit
4521  */
4522 struct ext4_mount_options {
4523 	unsigned long s_mount_opt;
4524 	unsigned long s_mount_opt2;
4525 	kuid_t s_resuid;
4526 	kgid_t s_resgid;
4527 	unsigned long s_commit_interval;
4528 	u32 s_min_batch_time, s_max_batch_time;
4529 #ifdef CONFIG_QUOTA
4530 	int s_jquota_fmt;
4531 	char *s_qf_names[MAXQUOTAS];
4532 #endif
4533 };
4534 
4535 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4536 {
4537 	struct ext4_super_block *es;
4538 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4539 	unsigned long old_sb_flags;
4540 	struct ext4_mount_options old_opts;
4541 	int enable_quota = 0;
4542 	ext4_group_t g;
4543 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4544 	int err = 0;
4545 #ifdef CONFIG_QUOTA
4546 	int i;
4547 #endif
4548 	char *orig_data = kstrdup(data, GFP_KERNEL);
4549 
4550 	/* Store the original options */
4551 	lock_super(sb);
4552 	old_sb_flags = sb->s_flags;
4553 	old_opts.s_mount_opt = sbi->s_mount_opt;
4554 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4555 	old_opts.s_resuid = sbi->s_resuid;
4556 	old_opts.s_resgid = sbi->s_resgid;
4557 	old_opts.s_commit_interval = sbi->s_commit_interval;
4558 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4559 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4560 #ifdef CONFIG_QUOTA
4561 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4562 	for (i = 0; i < MAXQUOTAS; i++)
4563 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4564 #endif
4565 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4566 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4567 
4568 	/*
4569 	 * Allow the "check" option to be passed as a remount option.
4570 	 */
4571 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4572 		err = -EINVAL;
4573 		goto restore_opts;
4574 	}
4575 
4576 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4577 		ext4_abort(sb, "Abort forced by user");
4578 
4579 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4580 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4581 
4582 	es = sbi->s_es;
4583 
4584 	if (sbi->s_journal) {
4585 		ext4_init_journal_params(sb, sbi->s_journal);
4586 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4587 	}
4588 
4589 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4590 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4591 			err = -EROFS;
4592 			goto restore_opts;
4593 		}
4594 
4595 		if (*flags & MS_RDONLY) {
4596 			err = dquot_suspend(sb, -1);
4597 			if (err < 0)
4598 				goto restore_opts;
4599 
4600 			/*
4601 			 * First of all, the unconditional stuff we have to do
4602 			 * to disable replay of the journal when we next remount
4603 			 */
4604 			sb->s_flags |= MS_RDONLY;
4605 
4606 			/*
4607 			 * OK, test if we are remounting a valid rw partition
4608 			 * readonly, and if so set the rdonly flag and then
4609 			 * mark the partition as valid again.
4610 			 */
4611 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4612 			    (sbi->s_mount_state & EXT4_VALID_FS))
4613 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4614 
4615 			if (sbi->s_journal)
4616 				ext4_mark_recovery_complete(sb, es);
4617 		} else {
4618 			/* Make sure we can mount this feature set readwrite */
4619 			if (!ext4_feature_set_ok(sb, 0)) {
4620 				err = -EROFS;
4621 				goto restore_opts;
4622 			}
4623 			/*
4624 			 * Make sure the group descriptor checksums
4625 			 * are sane.  If they aren't, refuse to remount r/w.
4626 			 */
4627 			for (g = 0; g < sbi->s_groups_count; g++) {
4628 				struct ext4_group_desc *gdp =
4629 					ext4_get_group_desc(sb, g, NULL);
4630 
4631 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4632 					ext4_msg(sb, KERN_ERR,
4633 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4634 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4635 					       le16_to_cpu(gdp->bg_checksum));
4636 					err = -EINVAL;
4637 					goto restore_opts;
4638 				}
4639 			}
4640 
4641 			/*
4642 			 * If we have an unprocessed orphan list hanging
4643 			 * around from a previously readonly bdev mount,
4644 			 * require a full umount/remount for now.
4645 			 */
4646 			if (es->s_last_orphan) {
4647 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4648 				       "remount RDWR because of unprocessed "
4649 				       "orphan inode list.  Please "
4650 				       "umount/remount instead");
4651 				err = -EINVAL;
4652 				goto restore_opts;
4653 			}
4654 
4655 			/*
4656 			 * Mounting a RDONLY partition read-write, so reread
4657 			 * and store the current valid flag.  (It may have
4658 			 * been changed by e2fsck since we originally mounted
4659 			 * the partition.)
4660 			 */
4661 			if (sbi->s_journal)
4662 				ext4_clear_journal_err(sb, es);
4663 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4664 			if (!ext4_setup_super(sb, es, 0))
4665 				sb->s_flags &= ~MS_RDONLY;
4666 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4667 						     EXT4_FEATURE_INCOMPAT_MMP))
4668 				if (ext4_multi_mount_protect(sb,
4669 						le64_to_cpu(es->s_mmp_block))) {
4670 					err = -EROFS;
4671 					goto restore_opts;
4672 				}
4673 			enable_quota = 1;
4674 		}
4675 	}
4676 
4677 	/*
4678 	 * Reinitialize lazy itable initialization thread based on
4679 	 * current settings
4680 	 */
4681 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4682 		ext4_unregister_li_request(sb);
4683 	else {
4684 		ext4_group_t first_not_zeroed;
4685 		first_not_zeroed = ext4_has_uninit_itable(sb);
4686 		ext4_register_li_request(sb, first_not_zeroed);
4687 	}
4688 
4689 	ext4_setup_system_zone(sb);
4690 	if (sbi->s_journal == NULL)
4691 		ext4_commit_super(sb, 1);
4692 
4693 	unlock_super(sb);
4694 #ifdef CONFIG_QUOTA
4695 	/* Release old quota file names */
4696 	for (i = 0; i < MAXQUOTAS; i++)
4697 		if (old_opts.s_qf_names[i] &&
4698 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4699 			kfree(old_opts.s_qf_names[i]);
4700 	if (enable_quota) {
4701 		if (sb_any_quota_suspended(sb))
4702 			dquot_resume(sb, -1);
4703 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4704 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4705 			err = ext4_enable_quotas(sb);
4706 			if (err) {
4707 				lock_super(sb);
4708 				goto restore_opts;
4709 			}
4710 		}
4711 	}
4712 #endif
4713 
4714 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4715 	kfree(orig_data);
4716 	return 0;
4717 
4718 restore_opts:
4719 	sb->s_flags = old_sb_flags;
4720 	sbi->s_mount_opt = old_opts.s_mount_opt;
4721 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4722 	sbi->s_resuid = old_opts.s_resuid;
4723 	sbi->s_resgid = old_opts.s_resgid;
4724 	sbi->s_commit_interval = old_opts.s_commit_interval;
4725 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4726 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4727 #ifdef CONFIG_QUOTA
4728 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4729 	for (i = 0; i < MAXQUOTAS; i++) {
4730 		if (sbi->s_qf_names[i] &&
4731 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4732 			kfree(sbi->s_qf_names[i]);
4733 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4734 	}
4735 #endif
4736 	unlock_super(sb);
4737 	kfree(orig_data);
4738 	return err;
4739 }
4740 
4741 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4742 {
4743 	struct super_block *sb = dentry->d_sb;
4744 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4745 	struct ext4_super_block *es = sbi->s_es;
4746 	ext4_fsblk_t overhead = 0;
4747 	u64 fsid;
4748 	s64 bfree;
4749 
4750 	if (!test_opt(sb, MINIX_DF))
4751 		overhead = sbi->s_overhead;
4752 
4753 	buf->f_type = EXT4_SUPER_MAGIC;
4754 	buf->f_bsize = sb->s_blocksize;
4755 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
4756 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4757 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4758 	/* prevent underflow in case that few free space is available */
4759 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4760 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4761 	if (buf->f_bfree < ext4_r_blocks_count(es))
4762 		buf->f_bavail = 0;
4763 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4764 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4765 	buf->f_namelen = EXT4_NAME_LEN;
4766 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4767 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4768 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4769 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4770 
4771 	return 0;
4772 }
4773 
4774 /* Helper function for writing quotas on sync - we need to start transaction
4775  * before quota file is locked for write. Otherwise the are possible deadlocks:
4776  * Process 1                         Process 2
4777  * ext4_create()                     quota_sync()
4778  *   jbd2_journal_start()                  write_dquot()
4779  *   dquot_initialize()                         down(dqio_mutex)
4780  *     down(dqio_mutex)                    jbd2_journal_start()
4781  *
4782  */
4783 
4784 #ifdef CONFIG_QUOTA
4785 
4786 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4787 {
4788 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4789 }
4790 
4791 static int ext4_write_dquot(struct dquot *dquot)
4792 {
4793 	int ret, err;
4794 	handle_t *handle;
4795 	struct inode *inode;
4796 
4797 	inode = dquot_to_inode(dquot);
4798 	handle = ext4_journal_start(inode,
4799 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4800 	if (IS_ERR(handle))
4801 		return PTR_ERR(handle);
4802 	ret = dquot_commit(dquot);
4803 	err = ext4_journal_stop(handle);
4804 	if (!ret)
4805 		ret = err;
4806 	return ret;
4807 }
4808 
4809 static int ext4_acquire_dquot(struct dquot *dquot)
4810 {
4811 	int ret, err;
4812 	handle_t *handle;
4813 
4814 	handle = ext4_journal_start(dquot_to_inode(dquot),
4815 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4816 	if (IS_ERR(handle))
4817 		return PTR_ERR(handle);
4818 	ret = dquot_acquire(dquot);
4819 	err = ext4_journal_stop(handle);
4820 	if (!ret)
4821 		ret = err;
4822 	return ret;
4823 }
4824 
4825 static int ext4_release_dquot(struct dquot *dquot)
4826 {
4827 	int ret, err;
4828 	handle_t *handle;
4829 
4830 	handle = ext4_journal_start(dquot_to_inode(dquot),
4831 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4832 	if (IS_ERR(handle)) {
4833 		/* Release dquot anyway to avoid endless cycle in dqput() */
4834 		dquot_release(dquot);
4835 		return PTR_ERR(handle);
4836 	}
4837 	ret = dquot_release(dquot);
4838 	err = ext4_journal_stop(handle);
4839 	if (!ret)
4840 		ret = err;
4841 	return ret;
4842 }
4843 
4844 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4845 {
4846 	/* Are we journaling quotas? */
4847 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4848 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4849 		dquot_mark_dquot_dirty(dquot);
4850 		return ext4_write_dquot(dquot);
4851 	} else {
4852 		return dquot_mark_dquot_dirty(dquot);
4853 	}
4854 }
4855 
4856 static int ext4_write_info(struct super_block *sb, int type)
4857 {
4858 	int ret, err;
4859 	handle_t *handle;
4860 
4861 	/* Data block + inode block */
4862 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
4863 	if (IS_ERR(handle))
4864 		return PTR_ERR(handle);
4865 	ret = dquot_commit_info(sb, type);
4866 	err = ext4_journal_stop(handle);
4867 	if (!ret)
4868 		ret = err;
4869 	return ret;
4870 }
4871 
4872 /*
4873  * Turn on quotas during mount time - we need to find
4874  * the quota file and such...
4875  */
4876 static int ext4_quota_on_mount(struct super_block *sb, int type)
4877 {
4878 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4879 					EXT4_SB(sb)->s_jquota_fmt, type);
4880 }
4881 
4882 /*
4883  * Standard function to be called on quota_on
4884  */
4885 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4886 			 struct path *path)
4887 {
4888 	int err;
4889 
4890 	if (!test_opt(sb, QUOTA))
4891 		return -EINVAL;
4892 
4893 	/* Quotafile not on the same filesystem? */
4894 	if (path->dentry->d_sb != sb)
4895 		return -EXDEV;
4896 	/* Journaling quota? */
4897 	if (EXT4_SB(sb)->s_qf_names[type]) {
4898 		/* Quotafile not in fs root? */
4899 		if (path->dentry->d_parent != sb->s_root)
4900 			ext4_msg(sb, KERN_WARNING,
4901 				"Quota file not on filesystem root. "
4902 				"Journaled quota will not work");
4903 	}
4904 
4905 	/*
4906 	 * When we journal data on quota file, we have to flush journal to see
4907 	 * all updates to the file when we bypass pagecache...
4908 	 */
4909 	if (EXT4_SB(sb)->s_journal &&
4910 	    ext4_should_journal_data(path->dentry->d_inode)) {
4911 		/*
4912 		 * We don't need to lock updates but journal_flush() could
4913 		 * otherwise be livelocked...
4914 		 */
4915 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4916 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4917 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4918 		if (err)
4919 			return err;
4920 	}
4921 
4922 	return dquot_quota_on(sb, type, format_id, path);
4923 }
4924 
4925 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4926 			     unsigned int flags)
4927 {
4928 	int err;
4929 	struct inode *qf_inode;
4930 	unsigned long qf_inums[MAXQUOTAS] = {
4931 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4932 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4933 	};
4934 
4935 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4936 
4937 	if (!qf_inums[type])
4938 		return -EPERM;
4939 
4940 	qf_inode = ext4_iget(sb, qf_inums[type]);
4941 	if (IS_ERR(qf_inode)) {
4942 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4943 		return PTR_ERR(qf_inode);
4944 	}
4945 
4946 	err = dquot_enable(qf_inode, type, format_id, flags);
4947 	iput(qf_inode);
4948 
4949 	return err;
4950 }
4951 
4952 /* Enable usage tracking for all quota types. */
4953 static int ext4_enable_quotas(struct super_block *sb)
4954 {
4955 	int type, err = 0;
4956 	unsigned long qf_inums[MAXQUOTAS] = {
4957 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4958 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4959 	};
4960 
4961 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
4962 	for (type = 0; type < MAXQUOTAS; type++) {
4963 		if (qf_inums[type]) {
4964 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
4965 						DQUOT_USAGE_ENABLED);
4966 			if (err) {
4967 				ext4_warning(sb,
4968 					"Failed to enable quota (type=%d) "
4969 					"tracking. Please run e2fsck to fix.",
4970 					type);
4971 				return err;
4972 			}
4973 		}
4974 	}
4975 	return 0;
4976 }
4977 
4978 /*
4979  * quota_on function that is used when QUOTA feature is set.
4980  */
4981 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
4982 				 int format_id)
4983 {
4984 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4985 		return -EINVAL;
4986 
4987 	/*
4988 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
4989 	 */
4990 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
4991 }
4992 
4993 static int ext4_quota_off(struct super_block *sb, int type)
4994 {
4995 	struct inode *inode = sb_dqopt(sb)->files[type];
4996 	handle_t *handle;
4997 
4998 	/* Force all delayed allocation blocks to be allocated.
4999 	 * Caller already holds s_umount sem */
5000 	if (test_opt(sb, DELALLOC))
5001 		sync_filesystem(sb);
5002 
5003 	if (!inode)
5004 		goto out;
5005 
5006 	/* Update modification times of quota files when userspace can
5007 	 * start looking at them */
5008 	handle = ext4_journal_start(inode, 1);
5009 	if (IS_ERR(handle))
5010 		goto out;
5011 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5012 	ext4_mark_inode_dirty(handle, inode);
5013 	ext4_journal_stop(handle);
5014 
5015 out:
5016 	return dquot_quota_off(sb, type);
5017 }
5018 
5019 /*
5020  * quota_off function that is used when QUOTA feature is set.
5021  */
5022 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5023 {
5024 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5025 		return -EINVAL;
5026 
5027 	/* Disable only the limits. */
5028 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5029 }
5030 
5031 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5032  * acquiring the locks... As quota files are never truncated and quota code
5033  * itself serializes the operations (and no one else should touch the files)
5034  * we don't have to be afraid of races */
5035 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5036 			       size_t len, loff_t off)
5037 {
5038 	struct inode *inode = sb_dqopt(sb)->files[type];
5039 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5040 	int err = 0;
5041 	int offset = off & (sb->s_blocksize - 1);
5042 	int tocopy;
5043 	size_t toread;
5044 	struct buffer_head *bh;
5045 	loff_t i_size = i_size_read(inode);
5046 
5047 	if (off > i_size)
5048 		return 0;
5049 	if (off+len > i_size)
5050 		len = i_size-off;
5051 	toread = len;
5052 	while (toread > 0) {
5053 		tocopy = sb->s_blocksize - offset < toread ?
5054 				sb->s_blocksize - offset : toread;
5055 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5056 		if (err)
5057 			return err;
5058 		if (!bh)	/* A hole? */
5059 			memset(data, 0, tocopy);
5060 		else
5061 			memcpy(data, bh->b_data+offset, tocopy);
5062 		brelse(bh);
5063 		offset = 0;
5064 		toread -= tocopy;
5065 		data += tocopy;
5066 		blk++;
5067 	}
5068 	return len;
5069 }
5070 
5071 /* Write to quotafile (we know the transaction is already started and has
5072  * enough credits) */
5073 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5074 				const char *data, size_t len, loff_t off)
5075 {
5076 	struct inode *inode = sb_dqopt(sb)->files[type];
5077 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5078 	int err = 0;
5079 	int offset = off & (sb->s_blocksize - 1);
5080 	struct buffer_head *bh;
5081 	handle_t *handle = journal_current_handle();
5082 
5083 	if (EXT4_SB(sb)->s_journal && !handle) {
5084 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5085 			" cancelled because transaction is not started",
5086 			(unsigned long long)off, (unsigned long long)len);
5087 		return -EIO;
5088 	}
5089 	/*
5090 	 * Since we account only one data block in transaction credits,
5091 	 * then it is impossible to cross a block boundary.
5092 	 */
5093 	if (sb->s_blocksize - offset < len) {
5094 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5095 			" cancelled because not block aligned",
5096 			(unsigned long long)off, (unsigned long long)len);
5097 		return -EIO;
5098 	}
5099 
5100 	bh = ext4_bread(handle, inode, blk, 1, &err);
5101 	if (!bh)
5102 		goto out;
5103 	err = ext4_journal_get_write_access(handle, bh);
5104 	if (err) {
5105 		brelse(bh);
5106 		goto out;
5107 	}
5108 	lock_buffer(bh);
5109 	memcpy(bh->b_data+offset, data, len);
5110 	flush_dcache_page(bh->b_page);
5111 	unlock_buffer(bh);
5112 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5113 	brelse(bh);
5114 out:
5115 	if (err)
5116 		return err;
5117 	if (inode->i_size < off + len) {
5118 		i_size_write(inode, off + len);
5119 		EXT4_I(inode)->i_disksize = inode->i_size;
5120 		ext4_mark_inode_dirty(handle, inode);
5121 	}
5122 	return len;
5123 }
5124 
5125 #endif
5126 
5127 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5128 		       const char *dev_name, void *data)
5129 {
5130 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5131 }
5132 
5133 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5134 static inline void register_as_ext2(void)
5135 {
5136 	int err = register_filesystem(&ext2_fs_type);
5137 	if (err)
5138 		printk(KERN_WARNING
5139 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5140 }
5141 
5142 static inline void unregister_as_ext2(void)
5143 {
5144 	unregister_filesystem(&ext2_fs_type);
5145 }
5146 
5147 static inline int ext2_feature_set_ok(struct super_block *sb)
5148 {
5149 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5150 		return 0;
5151 	if (sb->s_flags & MS_RDONLY)
5152 		return 1;
5153 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5154 		return 0;
5155 	return 1;
5156 }
5157 MODULE_ALIAS("ext2");
5158 #else
5159 static inline void register_as_ext2(void) { }
5160 static inline void unregister_as_ext2(void) { }
5161 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5162 #endif
5163 
5164 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5165 static inline void register_as_ext3(void)
5166 {
5167 	int err = register_filesystem(&ext3_fs_type);
5168 	if (err)
5169 		printk(KERN_WARNING
5170 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5171 }
5172 
5173 static inline void unregister_as_ext3(void)
5174 {
5175 	unregister_filesystem(&ext3_fs_type);
5176 }
5177 
5178 static inline int ext3_feature_set_ok(struct super_block *sb)
5179 {
5180 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5181 		return 0;
5182 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5183 		return 0;
5184 	if (sb->s_flags & MS_RDONLY)
5185 		return 1;
5186 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5187 		return 0;
5188 	return 1;
5189 }
5190 MODULE_ALIAS("ext3");
5191 #else
5192 static inline void register_as_ext3(void) { }
5193 static inline void unregister_as_ext3(void) { }
5194 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5195 #endif
5196 
5197 static struct file_system_type ext4_fs_type = {
5198 	.owner		= THIS_MODULE,
5199 	.name		= "ext4",
5200 	.mount		= ext4_mount,
5201 	.kill_sb	= kill_block_super,
5202 	.fs_flags	= FS_REQUIRES_DEV,
5203 };
5204 
5205 static int __init ext4_init_feat_adverts(void)
5206 {
5207 	struct ext4_features *ef;
5208 	int ret = -ENOMEM;
5209 
5210 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5211 	if (!ef)
5212 		goto out;
5213 
5214 	ef->f_kobj.kset = ext4_kset;
5215 	init_completion(&ef->f_kobj_unregister);
5216 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5217 				   "features");
5218 	if (ret) {
5219 		kfree(ef);
5220 		goto out;
5221 	}
5222 
5223 	ext4_feat = ef;
5224 	ret = 0;
5225 out:
5226 	return ret;
5227 }
5228 
5229 static void ext4_exit_feat_adverts(void)
5230 {
5231 	kobject_put(&ext4_feat->f_kobj);
5232 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5233 	kfree(ext4_feat);
5234 }
5235 
5236 /* Shared across all ext4 file systems */
5237 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5238 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5239 
5240 static int __init ext4_init_fs(void)
5241 {
5242 	int i, err;
5243 
5244 	ext4_li_info = NULL;
5245 	mutex_init(&ext4_li_mtx);
5246 
5247 	ext4_check_flag_values();
5248 
5249 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5250 		mutex_init(&ext4__aio_mutex[i]);
5251 		init_waitqueue_head(&ext4__ioend_wq[i]);
5252 	}
5253 
5254 	err = ext4_init_pageio();
5255 	if (err)
5256 		return err;
5257 	err = ext4_init_system_zone();
5258 	if (err)
5259 		goto out6;
5260 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5261 	if (!ext4_kset)
5262 		goto out5;
5263 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5264 
5265 	err = ext4_init_feat_adverts();
5266 	if (err)
5267 		goto out4;
5268 
5269 	err = ext4_init_mballoc();
5270 	if (err)
5271 		goto out3;
5272 
5273 	err = ext4_init_xattr();
5274 	if (err)
5275 		goto out2;
5276 	err = init_inodecache();
5277 	if (err)
5278 		goto out1;
5279 	register_as_ext3();
5280 	register_as_ext2();
5281 	err = register_filesystem(&ext4_fs_type);
5282 	if (err)
5283 		goto out;
5284 
5285 	return 0;
5286 out:
5287 	unregister_as_ext2();
5288 	unregister_as_ext3();
5289 	destroy_inodecache();
5290 out1:
5291 	ext4_exit_xattr();
5292 out2:
5293 	ext4_exit_mballoc();
5294 out3:
5295 	ext4_exit_feat_adverts();
5296 out4:
5297 	if (ext4_proc_root)
5298 		remove_proc_entry("fs/ext4", NULL);
5299 	kset_unregister(ext4_kset);
5300 out5:
5301 	ext4_exit_system_zone();
5302 out6:
5303 	ext4_exit_pageio();
5304 	return err;
5305 }
5306 
5307 static void __exit ext4_exit_fs(void)
5308 {
5309 	ext4_destroy_lazyinit_thread();
5310 	unregister_as_ext2();
5311 	unregister_as_ext3();
5312 	unregister_filesystem(&ext4_fs_type);
5313 	destroy_inodecache();
5314 	ext4_exit_xattr();
5315 	ext4_exit_mballoc();
5316 	ext4_exit_feat_adverts();
5317 	remove_proc_entry("fs/ext4", NULL);
5318 	kset_unregister(ext4_kset);
5319 	ext4_exit_system_zone();
5320 	ext4_exit_pageio();
5321 }
5322 
5323 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5324 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5325 MODULE_LICENSE("GPL");
5326 module_init(ext4_init_fs)
5327 module_exit(ext4_exit_fs)
5328