xref: /linux/fs/ext4/super.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
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 	ei->i_da_metadata_calc_last_lblock = 0;
952 	spin_lock_init(&(ei->i_block_reservation_lock));
953 #ifdef CONFIG_QUOTA
954 	ei->i_reserved_quota = 0;
955 #endif
956 	ei->jinode = NULL;
957 	INIT_LIST_HEAD(&ei->i_completed_io_list);
958 	spin_lock_init(&ei->i_completed_io_lock);
959 	ei->cur_aio_dio = NULL;
960 	ei->i_sync_tid = 0;
961 	ei->i_datasync_tid = 0;
962 	atomic_set(&ei->i_ioend_count, 0);
963 	atomic_set(&ei->i_aiodio_unwritten, 0);
964 
965 	return &ei->vfs_inode;
966 }
967 
968 static int ext4_drop_inode(struct inode *inode)
969 {
970 	int drop = generic_drop_inode(inode);
971 
972 	trace_ext4_drop_inode(inode, drop);
973 	return drop;
974 }
975 
976 static void ext4_i_callback(struct rcu_head *head)
977 {
978 	struct inode *inode = container_of(head, struct inode, i_rcu);
979 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
980 }
981 
982 static void ext4_destroy_inode(struct inode *inode)
983 {
984 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
985 		ext4_msg(inode->i_sb, KERN_ERR,
986 			 "Inode %lu (%p): orphan list check failed!",
987 			 inode->i_ino, EXT4_I(inode));
988 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
989 				EXT4_I(inode), sizeof(struct ext4_inode_info),
990 				true);
991 		dump_stack();
992 	}
993 	call_rcu(&inode->i_rcu, ext4_i_callback);
994 }
995 
996 static void init_once(void *foo)
997 {
998 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
999 
1000 	INIT_LIST_HEAD(&ei->i_orphan);
1001 #ifdef CONFIG_EXT4_FS_XATTR
1002 	init_rwsem(&ei->xattr_sem);
1003 #endif
1004 	init_rwsem(&ei->i_data_sem);
1005 	inode_init_once(&ei->vfs_inode);
1006 }
1007 
1008 static int init_inodecache(void)
1009 {
1010 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1011 					     sizeof(struct ext4_inode_info),
1012 					     0, (SLAB_RECLAIM_ACCOUNT|
1013 						SLAB_MEM_SPREAD),
1014 					     init_once);
1015 	if (ext4_inode_cachep == NULL)
1016 		return -ENOMEM;
1017 	return 0;
1018 }
1019 
1020 static void destroy_inodecache(void)
1021 {
1022 	kmem_cache_destroy(ext4_inode_cachep);
1023 }
1024 
1025 void ext4_clear_inode(struct inode *inode)
1026 {
1027 	invalidate_inode_buffers(inode);
1028 	clear_inode(inode);
1029 	dquot_drop(inode);
1030 	ext4_discard_preallocations(inode);
1031 	if (EXT4_I(inode)->jinode) {
1032 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1033 					       EXT4_I(inode)->jinode);
1034 		jbd2_free_inode(EXT4_I(inode)->jinode);
1035 		EXT4_I(inode)->jinode = NULL;
1036 	}
1037 }
1038 
1039 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1040 					u64 ino, u32 generation)
1041 {
1042 	struct inode *inode;
1043 
1044 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1045 		return ERR_PTR(-ESTALE);
1046 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1047 		return ERR_PTR(-ESTALE);
1048 
1049 	/* iget isn't really right if the inode is currently unallocated!!
1050 	 *
1051 	 * ext4_read_inode will return a bad_inode if the inode had been
1052 	 * deleted, so we should be safe.
1053 	 *
1054 	 * Currently we don't know the generation for parent directory, so
1055 	 * a generation of 0 means "accept any"
1056 	 */
1057 	inode = ext4_iget(sb, ino);
1058 	if (IS_ERR(inode))
1059 		return ERR_CAST(inode);
1060 	if (generation && inode->i_generation != generation) {
1061 		iput(inode);
1062 		return ERR_PTR(-ESTALE);
1063 	}
1064 
1065 	return inode;
1066 }
1067 
1068 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1069 					int fh_len, int fh_type)
1070 {
1071 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1072 				    ext4_nfs_get_inode);
1073 }
1074 
1075 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1076 					int fh_len, int fh_type)
1077 {
1078 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1079 				    ext4_nfs_get_inode);
1080 }
1081 
1082 /*
1083  * Try to release metadata pages (indirect blocks, directories) which are
1084  * mapped via the block device.  Since these pages could have journal heads
1085  * which would prevent try_to_free_buffers() from freeing them, we must use
1086  * jbd2 layer's try_to_free_buffers() function to release them.
1087  */
1088 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1089 				 gfp_t wait)
1090 {
1091 	journal_t *journal = EXT4_SB(sb)->s_journal;
1092 
1093 	WARN_ON(PageChecked(page));
1094 	if (!page_has_buffers(page))
1095 		return 0;
1096 	if (journal)
1097 		return jbd2_journal_try_to_free_buffers(journal, page,
1098 							wait & ~__GFP_WAIT);
1099 	return try_to_free_buffers(page);
1100 }
1101 
1102 #ifdef CONFIG_QUOTA
1103 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1104 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1105 
1106 static int ext4_write_dquot(struct dquot *dquot);
1107 static int ext4_acquire_dquot(struct dquot *dquot);
1108 static int ext4_release_dquot(struct dquot *dquot);
1109 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1110 static int ext4_write_info(struct super_block *sb, int type);
1111 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1112 			 struct path *path);
1113 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1114 				 int format_id);
1115 static int ext4_quota_off(struct super_block *sb, int type);
1116 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1117 static int ext4_quota_on_mount(struct super_block *sb, int type);
1118 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1119 			       size_t len, loff_t off);
1120 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1121 				const char *data, size_t len, loff_t off);
1122 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1123 			     unsigned int flags);
1124 static int ext4_enable_quotas(struct super_block *sb);
1125 
1126 static const struct dquot_operations ext4_quota_operations = {
1127 	.get_reserved_space = ext4_get_reserved_space,
1128 	.write_dquot	= ext4_write_dquot,
1129 	.acquire_dquot	= ext4_acquire_dquot,
1130 	.release_dquot	= ext4_release_dquot,
1131 	.mark_dirty	= ext4_mark_dquot_dirty,
1132 	.write_info	= ext4_write_info,
1133 	.alloc_dquot	= dquot_alloc,
1134 	.destroy_dquot	= dquot_destroy,
1135 };
1136 
1137 static const struct quotactl_ops ext4_qctl_operations = {
1138 	.quota_on	= ext4_quota_on,
1139 	.quota_off	= ext4_quota_off,
1140 	.quota_sync	= dquot_quota_sync,
1141 	.get_info	= dquot_get_dqinfo,
1142 	.set_info	= dquot_set_dqinfo,
1143 	.get_dqblk	= dquot_get_dqblk,
1144 	.set_dqblk	= dquot_set_dqblk
1145 };
1146 
1147 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1148 	.quota_on_meta	= ext4_quota_on_sysfile,
1149 	.quota_off	= ext4_quota_off_sysfile,
1150 	.quota_sync	= dquot_quota_sync,
1151 	.get_info	= dquot_get_dqinfo,
1152 	.set_info	= dquot_set_dqinfo,
1153 	.get_dqblk	= dquot_get_dqblk,
1154 	.set_dqblk	= dquot_set_dqblk
1155 };
1156 #endif
1157 
1158 static const struct super_operations ext4_sops = {
1159 	.alloc_inode	= ext4_alloc_inode,
1160 	.destroy_inode	= ext4_destroy_inode,
1161 	.write_inode	= ext4_write_inode,
1162 	.dirty_inode	= ext4_dirty_inode,
1163 	.drop_inode	= ext4_drop_inode,
1164 	.evict_inode	= ext4_evict_inode,
1165 	.put_super	= ext4_put_super,
1166 	.sync_fs	= ext4_sync_fs,
1167 	.freeze_fs	= ext4_freeze,
1168 	.unfreeze_fs	= ext4_unfreeze,
1169 	.statfs		= ext4_statfs,
1170 	.remount_fs	= ext4_remount,
1171 	.show_options	= ext4_show_options,
1172 #ifdef CONFIG_QUOTA
1173 	.quota_read	= ext4_quota_read,
1174 	.quota_write	= ext4_quota_write,
1175 #endif
1176 	.bdev_try_to_free_page = bdev_try_to_free_page,
1177 };
1178 
1179 static const struct super_operations ext4_nojournal_sops = {
1180 	.alloc_inode	= ext4_alloc_inode,
1181 	.destroy_inode	= ext4_destroy_inode,
1182 	.write_inode	= ext4_write_inode,
1183 	.dirty_inode	= ext4_dirty_inode,
1184 	.drop_inode	= ext4_drop_inode,
1185 	.evict_inode	= ext4_evict_inode,
1186 	.put_super	= ext4_put_super,
1187 	.statfs		= ext4_statfs,
1188 	.remount_fs	= ext4_remount,
1189 	.show_options	= ext4_show_options,
1190 #ifdef CONFIG_QUOTA
1191 	.quota_read	= ext4_quota_read,
1192 	.quota_write	= ext4_quota_write,
1193 #endif
1194 	.bdev_try_to_free_page = bdev_try_to_free_page,
1195 };
1196 
1197 static const struct export_operations ext4_export_ops = {
1198 	.fh_to_dentry = ext4_fh_to_dentry,
1199 	.fh_to_parent = ext4_fh_to_parent,
1200 	.get_parent = ext4_get_parent,
1201 };
1202 
1203 enum {
1204 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1205 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1206 	Opt_nouid32, Opt_debug, Opt_removed,
1207 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1208 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1209 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1210 	Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1211 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1212 	Opt_data_err_abort, Opt_data_err_ignore,
1213 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1214 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1215 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1216 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1217 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1218 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1219 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1220 	Opt_dioread_nolock, Opt_dioread_lock,
1221 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1222 };
1223 
1224 static const match_table_t tokens = {
1225 	{Opt_bsd_df, "bsddf"},
1226 	{Opt_minix_df, "minixdf"},
1227 	{Opt_grpid, "grpid"},
1228 	{Opt_grpid, "bsdgroups"},
1229 	{Opt_nogrpid, "nogrpid"},
1230 	{Opt_nogrpid, "sysvgroups"},
1231 	{Opt_resgid, "resgid=%u"},
1232 	{Opt_resuid, "resuid=%u"},
1233 	{Opt_sb, "sb=%u"},
1234 	{Opt_err_cont, "errors=continue"},
1235 	{Opt_err_panic, "errors=panic"},
1236 	{Opt_err_ro, "errors=remount-ro"},
1237 	{Opt_nouid32, "nouid32"},
1238 	{Opt_debug, "debug"},
1239 	{Opt_removed, "oldalloc"},
1240 	{Opt_removed, "orlov"},
1241 	{Opt_user_xattr, "user_xattr"},
1242 	{Opt_nouser_xattr, "nouser_xattr"},
1243 	{Opt_acl, "acl"},
1244 	{Opt_noacl, "noacl"},
1245 	{Opt_noload, "norecovery"},
1246 	{Opt_noload, "noload"},
1247 	{Opt_removed, "nobh"},
1248 	{Opt_removed, "bh"},
1249 	{Opt_commit, "commit=%u"},
1250 	{Opt_min_batch_time, "min_batch_time=%u"},
1251 	{Opt_max_batch_time, "max_batch_time=%u"},
1252 	{Opt_journal_dev, "journal_dev=%u"},
1253 	{Opt_journal_checksum, "journal_checksum"},
1254 	{Opt_journal_async_commit, "journal_async_commit"},
1255 	{Opt_abort, "abort"},
1256 	{Opt_data_journal, "data=journal"},
1257 	{Opt_data_ordered, "data=ordered"},
1258 	{Opt_data_writeback, "data=writeback"},
1259 	{Opt_data_err_abort, "data_err=abort"},
1260 	{Opt_data_err_ignore, "data_err=ignore"},
1261 	{Opt_offusrjquota, "usrjquota="},
1262 	{Opt_usrjquota, "usrjquota=%s"},
1263 	{Opt_offgrpjquota, "grpjquota="},
1264 	{Opt_grpjquota, "grpjquota=%s"},
1265 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1266 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1267 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1268 	{Opt_grpquota, "grpquota"},
1269 	{Opt_noquota, "noquota"},
1270 	{Opt_quota, "quota"},
1271 	{Opt_usrquota, "usrquota"},
1272 	{Opt_barrier, "barrier=%u"},
1273 	{Opt_barrier, "barrier"},
1274 	{Opt_nobarrier, "nobarrier"},
1275 	{Opt_i_version, "i_version"},
1276 	{Opt_stripe, "stripe=%u"},
1277 	{Opt_delalloc, "delalloc"},
1278 	{Opt_nodelalloc, "nodelalloc"},
1279 	{Opt_mblk_io_submit, "mblk_io_submit"},
1280 	{Opt_nomblk_io_submit, "nomblk_io_submit"},
1281 	{Opt_block_validity, "block_validity"},
1282 	{Opt_noblock_validity, "noblock_validity"},
1283 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1284 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1285 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1286 	{Opt_auto_da_alloc, "auto_da_alloc"},
1287 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1288 	{Opt_dioread_nolock, "dioread_nolock"},
1289 	{Opt_dioread_lock, "dioread_lock"},
1290 	{Opt_discard, "discard"},
1291 	{Opt_nodiscard, "nodiscard"},
1292 	{Opt_init_itable, "init_itable=%u"},
1293 	{Opt_init_itable, "init_itable"},
1294 	{Opt_noinit_itable, "noinit_itable"},
1295 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1296 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1297 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1298 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1299 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1300 	{Opt_err, NULL},
1301 };
1302 
1303 static ext4_fsblk_t get_sb_block(void **data)
1304 {
1305 	ext4_fsblk_t	sb_block;
1306 	char		*options = (char *) *data;
1307 
1308 	if (!options || strncmp(options, "sb=", 3) != 0)
1309 		return 1;	/* Default location */
1310 
1311 	options += 3;
1312 	/* TODO: use simple_strtoll with >32bit ext4 */
1313 	sb_block = simple_strtoul(options, &options, 0);
1314 	if (*options && *options != ',') {
1315 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1316 		       (char *) *data);
1317 		return 1;
1318 	}
1319 	if (*options == ',')
1320 		options++;
1321 	*data = (void *) options;
1322 
1323 	return sb_block;
1324 }
1325 
1326 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1327 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1328 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1329 
1330 #ifdef CONFIG_QUOTA
1331 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1332 {
1333 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1334 	char *qname;
1335 
1336 	if (sb_any_quota_loaded(sb) &&
1337 		!sbi->s_qf_names[qtype]) {
1338 		ext4_msg(sb, KERN_ERR,
1339 			"Cannot change journaled "
1340 			"quota options when quota turned on");
1341 		return -1;
1342 	}
1343 	qname = match_strdup(args);
1344 	if (!qname) {
1345 		ext4_msg(sb, KERN_ERR,
1346 			"Not enough memory for storing quotafile name");
1347 		return -1;
1348 	}
1349 	if (sbi->s_qf_names[qtype] &&
1350 		strcmp(sbi->s_qf_names[qtype], qname)) {
1351 		ext4_msg(sb, KERN_ERR,
1352 			"%s quota file already specified", QTYPE2NAME(qtype));
1353 		kfree(qname);
1354 		return -1;
1355 	}
1356 	sbi->s_qf_names[qtype] = qname;
1357 	if (strchr(sbi->s_qf_names[qtype], '/')) {
1358 		ext4_msg(sb, KERN_ERR,
1359 			"quotafile must be on filesystem root");
1360 		kfree(sbi->s_qf_names[qtype]);
1361 		sbi->s_qf_names[qtype] = NULL;
1362 		return -1;
1363 	}
1364 	set_opt(sb, QUOTA);
1365 	return 1;
1366 }
1367 
1368 static int clear_qf_name(struct super_block *sb, int qtype)
1369 {
1370 
1371 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1372 
1373 	if (sb_any_quota_loaded(sb) &&
1374 		sbi->s_qf_names[qtype]) {
1375 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1376 			" when quota turned on");
1377 		return -1;
1378 	}
1379 	/*
1380 	 * The space will be released later when all options are confirmed
1381 	 * to be correct
1382 	 */
1383 	sbi->s_qf_names[qtype] = NULL;
1384 	return 1;
1385 }
1386 #endif
1387 
1388 #define MOPT_SET	0x0001
1389 #define MOPT_CLEAR	0x0002
1390 #define MOPT_NOSUPPORT	0x0004
1391 #define MOPT_EXPLICIT	0x0008
1392 #define MOPT_CLEAR_ERR	0x0010
1393 #define MOPT_GTE0	0x0020
1394 #ifdef CONFIG_QUOTA
1395 #define MOPT_Q		0
1396 #define MOPT_QFMT	0x0040
1397 #else
1398 #define MOPT_Q		MOPT_NOSUPPORT
1399 #define MOPT_QFMT	MOPT_NOSUPPORT
1400 #endif
1401 #define MOPT_DATAJ	0x0080
1402 
1403 static const struct mount_opts {
1404 	int	token;
1405 	int	mount_opt;
1406 	int	flags;
1407 } ext4_mount_opts[] = {
1408 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1409 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1410 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1411 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1412 	{Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
1413 	{Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
1414 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1415 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1416 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
1417 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_CLEAR},
1418 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1419 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1420 	{Opt_delalloc, EXT4_MOUNT_DELALLOC, MOPT_SET | MOPT_EXPLICIT},
1421 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC, MOPT_CLEAR | MOPT_EXPLICIT},
1422 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM, MOPT_SET},
1423 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1424 				    EXT4_MOUNT_JOURNAL_CHECKSUM), MOPT_SET},
1425 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_SET},
1426 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1427 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1428 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1429 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_SET},
1430 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_CLEAR},
1431 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1432 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1433 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1434 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1435 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1436 	{Opt_commit, 0, MOPT_GTE0},
1437 	{Opt_max_batch_time, 0, MOPT_GTE0},
1438 	{Opt_min_batch_time, 0, MOPT_GTE0},
1439 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1440 	{Opt_init_itable, 0, MOPT_GTE0},
1441 	{Opt_stripe, 0, MOPT_GTE0},
1442 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
1443 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
1444 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
1445 #ifdef CONFIG_EXT4_FS_XATTR
1446 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1447 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1448 #else
1449 	{Opt_user_xattr, 0, MOPT_NOSUPPORT},
1450 	{Opt_nouser_xattr, 0, MOPT_NOSUPPORT},
1451 #endif
1452 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1453 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1454 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1455 #else
1456 	{Opt_acl, 0, MOPT_NOSUPPORT},
1457 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1458 #endif
1459 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1460 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1461 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1462 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1463 							MOPT_SET | MOPT_Q},
1464 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1465 							MOPT_SET | MOPT_Q},
1466 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1467 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1468 	{Opt_usrjquota, 0, MOPT_Q},
1469 	{Opt_grpjquota, 0, MOPT_Q},
1470 	{Opt_offusrjquota, 0, MOPT_Q},
1471 	{Opt_offgrpjquota, 0, MOPT_Q},
1472 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1473 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1474 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1475 	{Opt_err, 0, 0}
1476 };
1477 
1478 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1479 			    substring_t *args, unsigned long *journal_devnum,
1480 			    unsigned int *journal_ioprio, int is_remount)
1481 {
1482 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1483 	const struct mount_opts *m;
1484 	kuid_t uid;
1485 	kgid_t gid;
1486 	int arg = 0;
1487 
1488 #ifdef CONFIG_QUOTA
1489 	if (token == Opt_usrjquota)
1490 		return set_qf_name(sb, USRQUOTA, &args[0]);
1491 	else if (token == Opt_grpjquota)
1492 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1493 	else if (token == Opt_offusrjquota)
1494 		return clear_qf_name(sb, USRQUOTA);
1495 	else if (token == Opt_offgrpjquota)
1496 		return clear_qf_name(sb, GRPQUOTA);
1497 #endif
1498 	if (args->from && match_int(args, &arg))
1499 		return -1;
1500 	switch (token) {
1501 	case Opt_noacl:
1502 	case Opt_nouser_xattr:
1503 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1504 		break;
1505 	case Opt_sb:
1506 		return 1;	/* handled by get_sb_block() */
1507 	case Opt_removed:
1508 		ext4_msg(sb, KERN_WARNING,
1509 			 "Ignoring removed %s option", opt);
1510 		return 1;
1511 	case Opt_resuid:
1512 		uid = make_kuid(current_user_ns(), arg);
1513 		if (!uid_valid(uid)) {
1514 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1515 			return -1;
1516 		}
1517 		sbi->s_resuid = uid;
1518 		return 1;
1519 	case Opt_resgid:
1520 		gid = make_kgid(current_user_ns(), arg);
1521 		if (!gid_valid(gid)) {
1522 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1523 			return -1;
1524 		}
1525 		sbi->s_resgid = gid;
1526 		return 1;
1527 	case Opt_abort:
1528 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1529 		return 1;
1530 	case Opt_i_version:
1531 		sb->s_flags |= MS_I_VERSION;
1532 		return 1;
1533 	case Opt_journal_dev:
1534 		if (is_remount) {
1535 			ext4_msg(sb, KERN_ERR,
1536 				 "Cannot specify journal on remount");
1537 			return -1;
1538 		}
1539 		*journal_devnum = arg;
1540 		return 1;
1541 	case Opt_journal_ioprio:
1542 		if (arg < 0 || arg > 7)
1543 			return -1;
1544 		*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1545 		return 1;
1546 	}
1547 
1548 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1549 		if (token != m->token)
1550 			continue;
1551 		if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1552 			return -1;
1553 		if (m->flags & MOPT_EXPLICIT)
1554 			set_opt2(sb, EXPLICIT_DELALLOC);
1555 		if (m->flags & MOPT_CLEAR_ERR)
1556 			clear_opt(sb, ERRORS_MASK);
1557 		if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1558 			ext4_msg(sb, KERN_ERR, "Cannot change quota "
1559 				 "options when quota turned on");
1560 			return -1;
1561 		}
1562 
1563 		if (m->flags & MOPT_NOSUPPORT) {
1564 			ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1565 		} else if (token == Opt_commit) {
1566 			if (arg == 0)
1567 				arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1568 			sbi->s_commit_interval = HZ * arg;
1569 		} else if (token == Opt_max_batch_time) {
1570 			if (arg == 0)
1571 				arg = EXT4_DEF_MAX_BATCH_TIME;
1572 			sbi->s_max_batch_time = arg;
1573 		} else if (token == Opt_min_batch_time) {
1574 			sbi->s_min_batch_time = arg;
1575 		} else if (token == Opt_inode_readahead_blks) {
1576 			if (arg > (1 << 30))
1577 				return -1;
1578 			if (arg && !is_power_of_2(arg)) {
1579 				ext4_msg(sb, KERN_ERR,
1580 					 "EXT4-fs: inode_readahead_blks"
1581 					 " must be a power of 2");
1582 				return -1;
1583 			}
1584 			sbi->s_inode_readahead_blks = arg;
1585 		} else if (token == Opt_init_itable) {
1586 			set_opt(sb, INIT_INODE_TABLE);
1587 			if (!args->from)
1588 				arg = EXT4_DEF_LI_WAIT_MULT;
1589 			sbi->s_li_wait_mult = arg;
1590 		} else if (token == Opt_stripe) {
1591 			sbi->s_stripe = arg;
1592 		} else if (m->flags & MOPT_DATAJ) {
1593 			if (is_remount) {
1594 				if (!sbi->s_journal)
1595 					ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1596 				else if (test_opt(sb, DATA_FLAGS) !=
1597 					 m->mount_opt) {
1598 					ext4_msg(sb, KERN_ERR,
1599 					 "Cannot change data mode on remount");
1600 					return -1;
1601 				}
1602 			} else {
1603 				clear_opt(sb, DATA_FLAGS);
1604 				sbi->s_mount_opt |= m->mount_opt;
1605 			}
1606 #ifdef CONFIG_QUOTA
1607 		} else if (m->flags & MOPT_QFMT) {
1608 			if (sb_any_quota_loaded(sb) &&
1609 			    sbi->s_jquota_fmt != m->mount_opt) {
1610 				ext4_msg(sb, KERN_ERR, "Cannot "
1611 					 "change journaled quota options "
1612 					 "when quota turned on");
1613 				return -1;
1614 			}
1615 			sbi->s_jquota_fmt = m->mount_opt;
1616 #endif
1617 		} else {
1618 			if (!args->from)
1619 				arg = 1;
1620 			if (m->flags & MOPT_CLEAR)
1621 				arg = !arg;
1622 			else if (unlikely(!(m->flags & MOPT_SET))) {
1623 				ext4_msg(sb, KERN_WARNING,
1624 					 "buggy handling of option %s", opt);
1625 				WARN_ON(1);
1626 				return -1;
1627 			}
1628 			if (arg != 0)
1629 				sbi->s_mount_opt |= m->mount_opt;
1630 			else
1631 				sbi->s_mount_opt &= ~m->mount_opt;
1632 		}
1633 		return 1;
1634 	}
1635 	ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1636 		 "or missing value", opt);
1637 	return -1;
1638 }
1639 
1640 static int parse_options(char *options, struct super_block *sb,
1641 			 unsigned long *journal_devnum,
1642 			 unsigned int *journal_ioprio,
1643 			 int is_remount)
1644 {
1645 #ifdef CONFIG_QUOTA
1646 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1647 #endif
1648 	char *p;
1649 	substring_t args[MAX_OPT_ARGS];
1650 	int token;
1651 
1652 	if (!options)
1653 		return 1;
1654 
1655 	while ((p = strsep(&options, ",")) != NULL) {
1656 		if (!*p)
1657 			continue;
1658 		/*
1659 		 * Initialize args struct so we know whether arg was
1660 		 * found; some options take optional arguments.
1661 		 */
1662 		args[0].to = args[0].from = 0;
1663 		token = match_token(p, tokens, args);
1664 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1665 				     journal_ioprio, is_remount) < 0)
1666 			return 0;
1667 	}
1668 #ifdef CONFIG_QUOTA
1669 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1670 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1671 			clear_opt(sb, USRQUOTA);
1672 
1673 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1674 			clear_opt(sb, GRPQUOTA);
1675 
1676 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1677 			ext4_msg(sb, KERN_ERR, "old and new quota "
1678 					"format mixing");
1679 			return 0;
1680 		}
1681 
1682 		if (!sbi->s_jquota_fmt) {
1683 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1684 					"not specified");
1685 			return 0;
1686 		}
1687 	} else {
1688 		if (sbi->s_jquota_fmt) {
1689 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1690 					"specified with no journaling "
1691 					"enabled");
1692 			return 0;
1693 		}
1694 	}
1695 #endif
1696 	return 1;
1697 }
1698 
1699 static inline void ext4_show_quota_options(struct seq_file *seq,
1700 					   struct super_block *sb)
1701 {
1702 #if defined(CONFIG_QUOTA)
1703 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1704 
1705 	if (sbi->s_jquota_fmt) {
1706 		char *fmtname = "";
1707 
1708 		switch (sbi->s_jquota_fmt) {
1709 		case QFMT_VFS_OLD:
1710 			fmtname = "vfsold";
1711 			break;
1712 		case QFMT_VFS_V0:
1713 			fmtname = "vfsv0";
1714 			break;
1715 		case QFMT_VFS_V1:
1716 			fmtname = "vfsv1";
1717 			break;
1718 		}
1719 		seq_printf(seq, ",jqfmt=%s", fmtname);
1720 	}
1721 
1722 	if (sbi->s_qf_names[USRQUOTA])
1723 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1724 
1725 	if (sbi->s_qf_names[GRPQUOTA])
1726 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1727 
1728 	if (test_opt(sb, USRQUOTA))
1729 		seq_puts(seq, ",usrquota");
1730 
1731 	if (test_opt(sb, GRPQUOTA))
1732 		seq_puts(seq, ",grpquota");
1733 #endif
1734 }
1735 
1736 static const char *token2str(int token)
1737 {
1738 	static const struct match_token *t;
1739 
1740 	for (t = tokens; t->token != Opt_err; t++)
1741 		if (t->token == token && !strchr(t->pattern, '='))
1742 			break;
1743 	return t->pattern;
1744 }
1745 
1746 /*
1747  * Show an option if
1748  *  - it's set to a non-default value OR
1749  *  - if the per-sb default is different from the global default
1750  */
1751 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1752 			      int nodefs)
1753 {
1754 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1755 	struct ext4_super_block *es = sbi->s_es;
1756 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1757 	const struct mount_opts *m;
1758 	char sep = nodefs ? '\n' : ',';
1759 
1760 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1761 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1762 
1763 	if (sbi->s_sb_block != 1)
1764 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1765 
1766 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1767 		int want_set = m->flags & MOPT_SET;
1768 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1769 		    (m->flags & MOPT_CLEAR_ERR))
1770 			continue;
1771 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1772 			continue; /* skip if same as the default */
1773 		if ((want_set &&
1774 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1775 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1776 			continue; /* select Opt_noFoo vs Opt_Foo */
1777 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1778 	}
1779 
1780 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1781 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1782 		SEQ_OPTS_PRINT("resuid=%u",
1783 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1784 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1785 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1786 		SEQ_OPTS_PRINT("resgid=%u",
1787 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1788 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1789 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1790 		SEQ_OPTS_PUTS("errors=remount-ro");
1791 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1792 		SEQ_OPTS_PUTS("errors=continue");
1793 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1794 		SEQ_OPTS_PUTS("errors=panic");
1795 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1796 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1797 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1798 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1799 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1800 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1801 	if (sb->s_flags & MS_I_VERSION)
1802 		SEQ_OPTS_PUTS("i_version");
1803 	if (nodefs || sbi->s_stripe)
1804 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1805 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1806 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1807 			SEQ_OPTS_PUTS("data=journal");
1808 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1809 			SEQ_OPTS_PUTS("data=ordered");
1810 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1811 			SEQ_OPTS_PUTS("data=writeback");
1812 	}
1813 	if (nodefs ||
1814 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1815 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1816 			       sbi->s_inode_readahead_blks);
1817 
1818 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1819 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1820 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1821 
1822 	ext4_show_quota_options(seq, sb);
1823 	return 0;
1824 }
1825 
1826 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1827 {
1828 	return _ext4_show_options(seq, root->d_sb, 0);
1829 }
1830 
1831 static int options_seq_show(struct seq_file *seq, void *offset)
1832 {
1833 	struct super_block *sb = seq->private;
1834 	int rc;
1835 
1836 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1837 	rc = _ext4_show_options(seq, sb, 1);
1838 	seq_puts(seq, "\n");
1839 	return rc;
1840 }
1841 
1842 static int options_open_fs(struct inode *inode, struct file *file)
1843 {
1844 	return single_open(file, options_seq_show, PDE(inode)->data);
1845 }
1846 
1847 static const struct file_operations ext4_seq_options_fops = {
1848 	.owner = THIS_MODULE,
1849 	.open = options_open_fs,
1850 	.read = seq_read,
1851 	.llseek = seq_lseek,
1852 	.release = single_release,
1853 };
1854 
1855 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1856 			    int read_only)
1857 {
1858 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1859 	int res = 0;
1860 
1861 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1862 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1863 			 "forcing read-only mode");
1864 		res = MS_RDONLY;
1865 	}
1866 	if (read_only)
1867 		goto done;
1868 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1869 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1870 			 "running e2fsck is recommended");
1871 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1872 		ext4_msg(sb, KERN_WARNING,
1873 			 "warning: mounting fs with errors, "
1874 			 "running e2fsck is recommended");
1875 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1876 		 le16_to_cpu(es->s_mnt_count) >=
1877 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1878 		ext4_msg(sb, KERN_WARNING,
1879 			 "warning: maximal mount count reached, "
1880 			 "running e2fsck is recommended");
1881 	else if (le32_to_cpu(es->s_checkinterval) &&
1882 		(le32_to_cpu(es->s_lastcheck) +
1883 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1884 		ext4_msg(sb, KERN_WARNING,
1885 			 "warning: checktime reached, "
1886 			 "running e2fsck is recommended");
1887 	if (!sbi->s_journal)
1888 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1889 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1890 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1891 	le16_add_cpu(&es->s_mnt_count, 1);
1892 	es->s_mtime = cpu_to_le32(get_seconds());
1893 	ext4_update_dynamic_rev(sb);
1894 	if (sbi->s_journal)
1895 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1896 
1897 	ext4_commit_super(sb, 1);
1898 done:
1899 	if (test_opt(sb, DEBUG))
1900 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1901 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1902 			sb->s_blocksize,
1903 			sbi->s_groups_count,
1904 			EXT4_BLOCKS_PER_GROUP(sb),
1905 			EXT4_INODES_PER_GROUP(sb),
1906 			sbi->s_mount_opt, sbi->s_mount_opt2);
1907 
1908 	cleancache_init_fs(sb);
1909 	return res;
1910 }
1911 
1912 static int ext4_fill_flex_info(struct super_block *sb)
1913 {
1914 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1915 	struct ext4_group_desc *gdp = NULL;
1916 	ext4_group_t flex_group_count;
1917 	ext4_group_t flex_group;
1918 	unsigned int groups_per_flex = 0;
1919 	size_t size;
1920 	int i;
1921 
1922 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1923 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1924 		sbi->s_log_groups_per_flex = 0;
1925 		return 1;
1926 	}
1927 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1928 
1929 	/* We allocate both existing and potentially added groups */
1930 	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1931 			((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1932 			      EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1933 	size = flex_group_count * sizeof(struct flex_groups);
1934 	sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
1935 	if (sbi->s_flex_groups == NULL) {
1936 		ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
1937 			 flex_group_count);
1938 		goto failed;
1939 	}
1940 
1941 	for (i = 0; i < sbi->s_groups_count; i++) {
1942 		gdp = ext4_get_group_desc(sb, i, NULL);
1943 
1944 		flex_group = ext4_flex_group(sbi, i);
1945 		atomic_add(ext4_free_inodes_count(sb, gdp),
1946 			   &sbi->s_flex_groups[flex_group].free_inodes);
1947 		atomic_add(ext4_free_group_clusters(sb, gdp),
1948 			   &sbi->s_flex_groups[flex_group].free_clusters);
1949 		atomic_add(ext4_used_dirs_count(sb, gdp),
1950 			   &sbi->s_flex_groups[flex_group].used_dirs);
1951 	}
1952 
1953 	return 1;
1954 failed:
1955 	return 0;
1956 }
1957 
1958 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1959 				   struct ext4_group_desc *gdp)
1960 {
1961 	int offset;
1962 	__u16 crc = 0;
1963 	__le32 le_group = cpu_to_le32(block_group);
1964 
1965 	if ((sbi->s_es->s_feature_ro_compat &
1966 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1967 		/* Use new metadata_csum algorithm */
1968 		__u16 old_csum;
1969 		__u32 csum32;
1970 
1971 		old_csum = gdp->bg_checksum;
1972 		gdp->bg_checksum = 0;
1973 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1974 				     sizeof(le_group));
1975 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1976 				     sbi->s_desc_size);
1977 		gdp->bg_checksum = old_csum;
1978 
1979 		crc = csum32 & 0xFFFF;
1980 		goto out;
1981 	}
1982 
1983 	/* old crc16 code */
1984 	offset = offsetof(struct ext4_group_desc, bg_checksum);
1985 
1986 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1987 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1988 	crc = crc16(crc, (__u8 *)gdp, offset);
1989 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
1990 	/* for checksum of struct ext4_group_desc do the rest...*/
1991 	if ((sbi->s_es->s_feature_incompat &
1992 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1993 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1994 		crc = crc16(crc, (__u8 *)gdp + offset,
1995 			    le16_to_cpu(sbi->s_es->s_desc_size) -
1996 				offset);
1997 
1998 out:
1999 	return cpu_to_le16(crc);
2000 }
2001 
2002 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2003 				struct ext4_group_desc *gdp)
2004 {
2005 	if (ext4_has_group_desc_csum(sb) &&
2006 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2007 						      block_group, gdp)))
2008 		return 0;
2009 
2010 	return 1;
2011 }
2012 
2013 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2014 			      struct ext4_group_desc *gdp)
2015 {
2016 	if (!ext4_has_group_desc_csum(sb))
2017 		return;
2018 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2019 }
2020 
2021 /* Called at mount-time, super-block is locked */
2022 static int ext4_check_descriptors(struct super_block *sb,
2023 				  ext4_group_t *first_not_zeroed)
2024 {
2025 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2026 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2027 	ext4_fsblk_t last_block;
2028 	ext4_fsblk_t block_bitmap;
2029 	ext4_fsblk_t inode_bitmap;
2030 	ext4_fsblk_t inode_table;
2031 	int flexbg_flag = 0;
2032 	ext4_group_t i, grp = sbi->s_groups_count;
2033 
2034 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2035 		flexbg_flag = 1;
2036 
2037 	ext4_debug("Checking group descriptors");
2038 
2039 	for (i = 0; i < sbi->s_groups_count; i++) {
2040 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2041 
2042 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2043 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2044 		else
2045 			last_block = first_block +
2046 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2047 
2048 		if ((grp == sbi->s_groups_count) &&
2049 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2050 			grp = i;
2051 
2052 		block_bitmap = ext4_block_bitmap(sb, gdp);
2053 		if (block_bitmap < first_block || block_bitmap > last_block) {
2054 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2055 			       "Block bitmap for group %u not in group "
2056 			       "(block %llu)!", i, block_bitmap);
2057 			return 0;
2058 		}
2059 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2060 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2061 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2062 			       "Inode bitmap for group %u not in group "
2063 			       "(block %llu)!", i, inode_bitmap);
2064 			return 0;
2065 		}
2066 		inode_table = ext4_inode_table(sb, gdp);
2067 		if (inode_table < first_block ||
2068 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2069 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2070 			       "Inode table for group %u not in group "
2071 			       "(block %llu)!", i, inode_table);
2072 			return 0;
2073 		}
2074 		ext4_lock_group(sb, i);
2075 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2076 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2077 				 "Checksum for group %u failed (%u!=%u)",
2078 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2079 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2080 			if (!(sb->s_flags & MS_RDONLY)) {
2081 				ext4_unlock_group(sb, i);
2082 				return 0;
2083 			}
2084 		}
2085 		ext4_unlock_group(sb, i);
2086 		if (!flexbg_flag)
2087 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2088 	}
2089 	if (NULL != first_not_zeroed)
2090 		*first_not_zeroed = grp;
2091 
2092 	ext4_free_blocks_count_set(sbi->s_es,
2093 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2094 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2095 	return 1;
2096 }
2097 
2098 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2099  * the superblock) which were deleted from all directories, but held open by
2100  * a process at the time of a crash.  We walk the list and try to delete these
2101  * inodes at recovery time (only with a read-write filesystem).
2102  *
2103  * In order to keep the orphan inode chain consistent during traversal (in
2104  * case of crash during recovery), we link each inode into the superblock
2105  * orphan list_head and handle it the same way as an inode deletion during
2106  * normal operation (which journals the operations for us).
2107  *
2108  * We only do an iget() and an iput() on each inode, which is very safe if we
2109  * accidentally point at an in-use or already deleted inode.  The worst that
2110  * can happen in this case is that we get a "bit already cleared" message from
2111  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2112  * e2fsck was run on this filesystem, and it must have already done the orphan
2113  * inode cleanup for us, so we can safely abort without any further action.
2114  */
2115 static void ext4_orphan_cleanup(struct super_block *sb,
2116 				struct ext4_super_block *es)
2117 {
2118 	unsigned int s_flags = sb->s_flags;
2119 	int nr_orphans = 0, nr_truncates = 0;
2120 #ifdef CONFIG_QUOTA
2121 	int i;
2122 #endif
2123 	if (!es->s_last_orphan) {
2124 		jbd_debug(4, "no orphan inodes to clean up\n");
2125 		return;
2126 	}
2127 
2128 	if (bdev_read_only(sb->s_bdev)) {
2129 		ext4_msg(sb, KERN_ERR, "write access "
2130 			"unavailable, skipping orphan cleanup");
2131 		return;
2132 	}
2133 
2134 	/* Check if feature set would not allow a r/w mount */
2135 	if (!ext4_feature_set_ok(sb, 0)) {
2136 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2137 			 "unknown ROCOMPAT features");
2138 		return;
2139 	}
2140 
2141 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2142 		if (es->s_last_orphan)
2143 			jbd_debug(1, "Errors on filesystem, "
2144 				  "clearing orphan list.\n");
2145 		es->s_last_orphan = 0;
2146 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2147 		return;
2148 	}
2149 
2150 	if (s_flags & MS_RDONLY) {
2151 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2152 		sb->s_flags &= ~MS_RDONLY;
2153 	}
2154 #ifdef CONFIG_QUOTA
2155 	/* Needed for iput() to work correctly and not trash data */
2156 	sb->s_flags |= MS_ACTIVE;
2157 	/* Turn on quotas so that they are updated correctly */
2158 	for (i = 0; i < MAXQUOTAS; i++) {
2159 		if (EXT4_SB(sb)->s_qf_names[i]) {
2160 			int ret = ext4_quota_on_mount(sb, i);
2161 			if (ret < 0)
2162 				ext4_msg(sb, KERN_ERR,
2163 					"Cannot turn on journaled "
2164 					"quota: error %d", ret);
2165 		}
2166 	}
2167 #endif
2168 
2169 	while (es->s_last_orphan) {
2170 		struct inode *inode;
2171 
2172 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2173 		if (IS_ERR(inode)) {
2174 			es->s_last_orphan = 0;
2175 			break;
2176 		}
2177 
2178 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2179 		dquot_initialize(inode);
2180 		if (inode->i_nlink) {
2181 			ext4_msg(sb, KERN_DEBUG,
2182 				"%s: truncating inode %lu to %lld bytes",
2183 				__func__, inode->i_ino, inode->i_size);
2184 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2185 				  inode->i_ino, inode->i_size);
2186 			ext4_truncate(inode);
2187 			nr_truncates++;
2188 		} else {
2189 			ext4_msg(sb, KERN_DEBUG,
2190 				"%s: deleting unreferenced inode %lu",
2191 				__func__, inode->i_ino);
2192 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2193 				  inode->i_ino);
2194 			nr_orphans++;
2195 		}
2196 		iput(inode);  /* The delete magic happens here! */
2197 	}
2198 
2199 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2200 
2201 	if (nr_orphans)
2202 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2203 		       PLURAL(nr_orphans));
2204 	if (nr_truncates)
2205 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2206 		       PLURAL(nr_truncates));
2207 #ifdef CONFIG_QUOTA
2208 	/* Turn quotas off */
2209 	for (i = 0; i < MAXQUOTAS; i++) {
2210 		if (sb_dqopt(sb)->files[i])
2211 			dquot_quota_off(sb, i);
2212 	}
2213 #endif
2214 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2215 }
2216 
2217 /*
2218  * Maximal extent format file size.
2219  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2220  * extent format containers, within a sector_t, and within i_blocks
2221  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2222  * so that won't be a limiting factor.
2223  *
2224  * However there is other limiting factor. We do store extents in the form
2225  * of starting block and length, hence the resulting length of the extent
2226  * covering maximum file size must fit into on-disk format containers as
2227  * well. Given that length is always by 1 unit bigger than max unit (because
2228  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2229  *
2230  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2231  */
2232 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2233 {
2234 	loff_t res;
2235 	loff_t upper_limit = MAX_LFS_FILESIZE;
2236 
2237 	/* small i_blocks in vfs inode? */
2238 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2239 		/*
2240 		 * CONFIG_LBDAF is not enabled implies the inode
2241 		 * i_block represent total blocks in 512 bytes
2242 		 * 32 == size of vfs inode i_blocks * 8
2243 		 */
2244 		upper_limit = (1LL << 32) - 1;
2245 
2246 		/* total blocks in file system block size */
2247 		upper_limit >>= (blkbits - 9);
2248 		upper_limit <<= blkbits;
2249 	}
2250 
2251 	/*
2252 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2253 	 * by one fs block, so ee_len can cover the extent of maximum file
2254 	 * size
2255 	 */
2256 	res = (1LL << 32) - 1;
2257 	res <<= blkbits;
2258 
2259 	/* Sanity check against vm- & vfs- imposed limits */
2260 	if (res > upper_limit)
2261 		res = upper_limit;
2262 
2263 	return res;
2264 }
2265 
2266 /*
2267  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2268  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2269  * We need to be 1 filesystem block less than the 2^48 sector limit.
2270  */
2271 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2272 {
2273 	loff_t res = EXT4_NDIR_BLOCKS;
2274 	int meta_blocks;
2275 	loff_t upper_limit;
2276 	/* This is calculated to be the largest file size for a dense, block
2277 	 * mapped file such that the file's total number of 512-byte sectors,
2278 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2279 	 *
2280 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2281 	 * number of 512-byte sectors of the file.
2282 	 */
2283 
2284 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2285 		/*
2286 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2287 		 * the inode i_block field represents total file blocks in
2288 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2289 		 */
2290 		upper_limit = (1LL << 32) - 1;
2291 
2292 		/* total blocks in file system block size */
2293 		upper_limit >>= (bits - 9);
2294 
2295 	} else {
2296 		/*
2297 		 * We use 48 bit ext4_inode i_blocks
2298 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2299 		 * represent total number of blocks in
2300 		 * file system block size
2301 		 */
2302 		upper_limit = (1LL << 48) - 1;
2303 
2304 	}
2305 
2306 	/* indirect blocks */
2307 	meta_blocks = 1;
2308 	/* double indirect blocks */
2309 	meta_blocks += 1 + (1LL << (bits-2));
2310 	/* tripple indirect blocks */
2311 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2312 
2313 	upper_limit -= meta_blocks;
2314 	upper_limit <<= bits;
2315 
2316 	res += 1LL << (bits-2);
2317 	res += 1LL << (2*(bits-2));
2318 	res += 1LL << (3*(bits-2));
2319 	res <<= bits;
2320 	if (res > upper_limit)
2321 		res = upper_limit;
2322 
2323 	if (res > MAX_LFS_FILESIZE)
2324 		res = MAX_LFS_FILESIZE;
2325 
2326 	return res;
2327 }
2328 
2329 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2330 				   ext4_fsblk_t logical_sb_block, int nr)
2331 {
2332 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2333 	ext4_group_t bg, first_meta_bg;
2334 	int has_super = 0;
2335 
2336 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2337 
2338 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2339 	    nr < first_meta_bg)
2340 		return logical_sb_block + nr + 1;
2341 	bg = sbi->s_desc_per_block * nr;
2342 	if (ext4_bg_has_super(sb, bg))
2343 		has_super = 1;
2344 
2345 	return (has_super + ext4_group_first_block_no(sb, bg));
2346 }
2347 
2348 /**
2349  * ext4_get_stripe_size: Get the stripe size.
2350  * @sbi: In memory super block info
2351  *
2352  * If we have specified it via mount option, then
2353  * use the mount option value. If the value specified at mount time is
2354  * greater than the blocks per group use the super block value.
2355  * If the super block value is greater than blocks per group return 0.
2356  * Allocator needs it be less than blocks per group.
2357  *
2358  */
2359 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2360 {
2361 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2362 	unsigned long stripe_width =
2363 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2364 	int ret;
2365 
2366 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2367 		ret = sbi->s_stripe;
2368 	else if (stripe_width <= sbi->s_blocks_per_group)
2369 		ret = stripe_width;
2370 	else if (stride <= sbi->s_blocks_per_group)
2371 		ret = stride;
2372 	else
2373 		ret = 0;
2374 
2375 	/*
2376 	 * If the stripe width is 1, this makes no sense and
2377 	 * we set it to 0 to turn off stripe handling code.
2378 	 */
2379 	if (ret <= 1)
2380 		ret = 0;
2381 
2382 	return ret;
2383 }
2384 
2385 /* sysfs supprt */
2386 
2387 struct ext4_attr {
2388 	struct attribute attr;
2389 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2390 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2391 			 const char *, size_t);
2392 	int offset;
2393 };
2394 
2395 static int parse_strtoul(const char *buf,
2396 		unsigned long max, unsigned long *value)
2397 {
2398 	char *endp;
2399 
2400 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2401 	endp = skip_spaces(endp);
2402 	if (*endp || *value > max)
2403 		return -EINVAL;
2404 
2405 	return 0;
2406 }
2407 
2408 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2409 					      struct ext4_sb_info *sbi,
2410 					      char *buf)
2411 {
2412 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2413 		(s64) EXT4_C2B(sbi,
2414 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2415 }
2416 
2417 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2418 					 struct ext4_sb_info *sbi, char *buf)
2419 {
2420 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2421 
2422 	if (!sb->s_bdev->bd_part)
2423 		return snprintf(buf, PAGE_SIZE, "0\n");
2424 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2425 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2426 			 sbi->s_sectors_written_start) >> 1);
2427 }
2428 
2429 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2430 					  struct ext4_sb_info *sbi, char *buf)
2431 {
2432 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2433 
2434 	if (!sb->s_bdev->bd_part)
2435 		return snprintf(buf, PAGE_SIZE, "0\n");
2436 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2437 			(unsigned long long)(sbi->s_kbytes_written +
2438 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2439 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2440 }
2441 
2442 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2443 					  struct ext4_sb_info *sbi,
2444 					  const char *buf, size_t count)
2445 {
2446 	unsigned long t;
2447 
2448 	if (parse_strtoul(buf, 0x40000000, &t))
2449 		return -EINVAL;
2450 
2451 	if (t && !is_power_of_2(t))
2452 		return -EINVAL;
2453 
2454 	sbi->s_inode_readahead_blks = t;
2455 	return count;
2456 }
2457 
2458 static ssize_t sbi_ui_show(struct ext4_attr *a,
2459 			   struct ext4_sb_info *sbi, char *buf)
2460 {
2461 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2462 
2463 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2464 }
2465 
2466 static ssize_t sbi_ui_store(struct ext4_attr *a,
2467 			    struct ext4_sb_info *sbi,
2468 			    const char *buf, size_t count)
2469 {
2470 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2471 	unsigned long t;
2472 
2473 	if (parse_strtoul(buf, 0xffffffff, &t))
2474 		return -EINVAL;
2475 	*ui = t;
2476 	return count;
2477 }
2478 
2479 static ssize_t trigger_test_error(struct ext4_attr *a,
2480 				  struct ext4_sb_info *sbi,
2481 				  const char *buf, size_t count)
2482 {
2483 	int len = count;
2484 
2485 	if (!capable(CAP_SYS_ADMIN))
2486 		return -EPERM;
2487 
2488 	if (len && buf[len-1] == '\n')
2489 		len--;
2490 
2491 	if (len)
2492 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2493 	return count;
2494 }
2495 
2496 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2497 static struct ext4_attr ext4_attr_##_name = {			\
2498 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2499 	.show	= _show,					\
2500 	.store	= _store,					\
2501 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2502 }
2503 #define EXT4_ATTR(name, mode, show, store) \
2504 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2505 
2506 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2507 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2508 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2509 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2510 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2511 #define ATTR_LIST(name) &ext4_attr_##name.attr
2512 
2513 EXT4_RO_ATTR(delayed_allocation_blocks);
2514 EXT4_RO_ATTR(session_write_kbytes);
2515 EXT4_RO_ATTR(lifetime_write_kbytes);
2516 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2517 		 inode_readahead_blks_store, s_inode_readahead_blks);
2518 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2519 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2520 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2521 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2522 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2523 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2524 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2525 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2526 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2527 
2528 static struct attribute *ext4_attrs[] = {
2529 	ATTR_LIST(delayed_allocation_blocks),
2530 	ATTR_LIST(session_write_kbytes),
2531 	ATTR_LIST(lifetime_write_kbytes),
2532 	ATTR_LIST(inode_readahead_blks),
2533 	ATTR_LIST(inode_goal),
2534 	ATTR_LIST(mb_stats),
2535 	ATTR_LIST(mb_max_to_scan),
2536 	ATTR_LIST(mb_min_to_scan),
2537 	ATTR_LIST(mb_order2_req),
2538 	ATTR_LIST(mb_stream_req),
2539 	ATTR_LIST(mb_group_prealloc),
2540 	ATTR_LIST(max_writeback_mb_bump),
2541 	ATTR_LIST(trigger_fs_error),
2542 	NULL,
2543 };
2544 
2545 /* Features this copy of ext4 supports */
2546 EXT4_INFO_ATTR(lazy_itable_init);
2547 EXT4_INFO_ATTR(batched_discard);
2548 
2549 static struct attribute *ext4_feat_attrs[] = {
2550 	ATTR_LIST(lazy_itable_init),
2551 	ATTR_LIST(batched_discard),
2552 	NULL,
2553 };
2554 
2555 static ssize_t ext4_attr_show(struct kobject *kobj,
2556 			      struct attribute *attr, char *buf)
2557 {
2558 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2559 						s_kobj);
2560 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2561 
2562 	return a->show ? a->show(a, sbi, buf) : 0;
2563 }
2564 
2565 static ssize_t ext4_attr_store(struct kobject *kobj,
2566 			       struct attribute *attr,
2567 			       const char *buf, size_t len)
2568 {
2569 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2570 						s_kobj);
2571 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2572 
2573 	return a->store ? a->store(a, sbi, buf, len) : 0;
2574 }
2575 
2576 static void ext4_sb_release(struct kobject *kobj)
2577 {
2578 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2579 						s_kobj);
2580 	complete(&sbi->s_kobj_unregister);
2581 }
2582 
2583 static const struct sysfs_ops ext4_attr_ops = {
2584 	.show	= ext4_attr_show,
2585 	.store	= ext4_attr_store,
2586 };
2587 
2588 static struct kobj_type ext4_ktype = {
2589 	.default_attrs	= ext4_attrs,
2590 	.sysfs_ops	= &ext4_attr_ops,
2591 	.release	= ext4_sb_release,
2592 };
2593 
2594 static void ext4_feat_release(struct kobject *kobj)
2595 {
2596 	complete(&ext4_feat->f_kobj_unregister);
2597 }
2598 
2599 static struct kobj_type ext4_feat_ktype = {
2600 	.default_attrs	= ext4_feat_attrs,
2601 	.sysfs_ops	= &ext4_attr_ops,
2602 	.release	= ext4_feat_release,
2603 };
2604 
2605 /*
2606  * Check whether this filesystem can be mounted based on
2607  * the features present and the RDONLY/RDWR mount requested.
2608  * Returns 1 if this filesystem can be mounted as requested,
2609  * 0 if it cannot be.
2610  */
2611 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2612 {
2613 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2614 		ext4_msg(sb, KERN_ERR,
2615 			"Couldn't mount because of "
2616 			"unsupported optional features (%x)",
2617 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2618 			~EXT4_FEATURE_INCOMPAT_SUPP));
2619 		return 0;
2620 	}
2621 
2622 	if (readonly)
2623 		return 1;
2624 
2625 	/* Check that feature set is OK for a read-write mount */
2626 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2627 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2628 			 "unsupported optional features (%x)",
2629 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2630 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2631 		return 0;
2632 	}
2633 	/*
2634 	 * Large file size enabled file system can only be mounted
2635 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2636 	 */
2637 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2638 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2639 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2640 				 "cannot be mounted RDWR without "
2641 				 "CONFIG_LBDAF");
2642 			return 0;
2643 		}
2644 	}
2645 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2646 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2647 		ext4_msg(sb, KERN_ERR,
2648 			 "Can't support bigalloc feature without "
2649 			 "extents feature\n");
2650 		return 0;
2651 	}
2652 
2653 #ifndef CONFIG_QUOTA
2654 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2655 	    !readonly) {
2656 		ext4_msg(sb, KERN_ERR,
2657 			 "Filesystem with quota feature cannot be mounted RDWR "
2658 			 "without CONFIG_QUOTA");
2659 		return 0;
2660 	}
2661 #endif  /* CONFIG_QUOTA */
2662 	return 1;
2663 }
2664 
2665 /*
2666  * This function is called once a day if we have errors logged
2667  * on the file system
2668  */
2669 static void print_daily_error_info(unsigned long arg)
2670 {
2671 	struct super_block *sb = (struct super_block *) arg;
2672 	struct ext4_sb_info *sbi;
2673 	struct ext4_super_block *es;
2674 
2675 	sbi = EXT4_SB(sb);
2676 	es = sbi->s_es;
2677 
2678 	if (es->s_error_count)
2679 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2680 			 le32_to_cpu(es->s_error_count));
2681 	if (es->s_first_error_time) {
2682 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2683 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2684 		       (int) sizeof(es->s_first_error_func),
2685 		       es->s_first_error_func,
2686 		       le32_to_cpu(es->s_first_error_line));
2687 		if (es->s_first_error_ino)
2688 			printk(": inode %u",
2689 			       le32_to_cpu(es->s_first_error_ino));
2690 		if (es->s_first_error_block)
2691 			printk(": block %llu", (unsigned long long)
2692 			       le64_to_cpu(es->s_first_error_block));
2693 		printk("\n");
2694 	}
2695 	if (es->s_last_error_time) {
2696 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2697 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2698 		       (int) sizeof(es->s_last_error_func),
2699 		       es->s_last_error_func,
2700 		       le32_to_cpu(es->s_last_error_line));
2701 		if (es->s_last_error_ino)
2702 			printk(": inode %u",
2703 			       le32_to_cpu(es->s_last_error_ino));
2704 		if (es->s_last_error_block)
2705 			printk(": block %llu", (unsigned long long)
2706 			       le64_to_cpu(es->s_last_error_block));
2707 		printk("\n");
2708 	}
2709 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2710 }
2711 
2712 /* Find next suitable group and run ext4_init_inode_table */
2713 static int ext4_run_li_request(struct ext4_li_request *elr)
2714 {
2715 	struct ext4_group_desc *gdp = NULL;
2716 	ext4_group_t group, ngroups;
2717 	struct super_block *sb;
2718 	unsigned long timeout = 0;
2719 	int ret = 0;
2720 
2721 	sb = elr->lr_super;
2722 	ngroups = EXT4_SB(sb)->s_groups_count;
2723 
2724 	sb_start_write(sb);
2725 	for (group = elr->lr_next_group; group < ngroups; group++) {
2726 		gdp = ext4_get_group_desc(sb, group, NULL);
2727 		if (!gdp) {
2728 			ret = 1;
2729 			break;
2730 		}
2731 
2732 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2733 			break;
2734 	}
2735 
2736 	if (group == ngroups)
2737 		ret = 1;
2738 
2739 	if (!ret) {
2740 		timeout = jiffies;
2741 		ret = ext4_init_inode_table(sb, group,
2742 					    elr->lr_timeout ? 0 : 1);
2743 		if (elr->lr_timeout == 0) {
2744 			timeout = (jiffies - timeout) *
2745 				  elr->lr_sbi->s_li_wait_mult;
2746 			elr->lr_timeout = timeout;
2747 		}
2748 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2749 		elr->lr_next_group = group + 1;
2750 	}
2751 	sb_end_write(sb);
2752 
2753 	return ret;
2754 }
2755 
2756 /*
2757  * Remove lr_request from the list_request and free the
2758  * request structure. Should be called with li_list_mtx held
2759  */
2760 static void ext4_remove_li_request(struct ext4_li_request *elr)
2761 {
2762 	struct ext4_sb_info *sbi;
2763 
2764 	if (!elr)
2765 		return;
2766 
2767 	sbi = elr->lr_sbi;
2768 
2769 	list_del(&elr->lr_request);
2770 	sbi->s_li_request = NULL;
2771 	kfree(elr);
2772 }
2773 
2774 static void ext4_unregister_li_request(struct super_block *sb)
2775 {
2776 	mutex_lock(&ext4_li_mtx);
2777 	if (!ext4_li_info) {
2778 		mutex_unlock(&ext4_li_mtx);
2779 		return;
2780 	}
2781 
2782 	mutex_lock(&ext4_li_info->li_list_mtx);
2783 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2784 	mutex_unlock(&ext4_li_info->li_list_mtx);
2785 	mutex_unlock(&ext4_li_mtx);
2786 }
2787 
2788 static struct task_struct *ext4_lazyinit_task;
2789 
2790 /*
2791  * This is the function where ext4lazyinit thread lives. It walks
2792  * through the request list searching for next scheduled filesystem.
2793  * When such a fs is found, run the lazy initialization request
2794  * (ext4_rn_li_request) and keep track of the time spend in this
2795  * function. Based on that time we compute next schedule time of
2796  * the request. When walking through the list is complete, compute
2797  * next waking time and put itself into sleep.
2798  */
2799 static int ext4_lazyinit_thread(void *arg)
2800 {
2801 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2802 	struct list_head *pos, *n;
2803 	struct ext4_li_request *elr;
2804 	unsigned long next_wakeup, cur;
2805 
2806 	BUG_ON(NULL == eli);
2807 
2808 cont_thread:
2809 	while (true) {
2810 		next_wakeup = MAX_JIFFY_OFFSET;
2811 
2812 		mutex_lock(&eli->li_list_mtx);
2813 		if (list_empty(&eli->li_request_list)) {
2814 			mutex_unlock(&eli->li_list_mtx);
2815 			goto exit_thread;
2816 		}
2817 
2818 		list_for_each_safe(pos, n, &eli->li_request_list) {
2819 			elr = list_entry(pos, struct ext4_li_request,
2820 					 lr_request);
2821 
2822 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2823 				if (ext4_run_li_request(elr) != 0) {
2824 					/* error, remove the lazy_init job */
2825 					ext4_remove_li_request(elr);
2826 					continue;
2827 				}
2828 			}
2829 
2830 			if (time_before(elr->lr_next_sched, next_wakeup))
2831 				next_wakeup = elr->lr_next_sched;
2832 		}
2833 		mutex_unlock(&eli->li_list_mtx);
2834 
2835 		try_to_freeze();
2836 
2837 		cur = jiffies;
2838 		if ((time_after_eq(cur, next_wakeup)) ||
2839 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2840 			cond_resched();
2841 			continue;
2842 		}
2843 
2844 		schedule_timeout_interruptible(next_wakeup - cur);
2845 
2846 		if (kthread_should_stop()) {
2847 			ext4_clear_request_list();
2848 			goto exit_thread;
2849 		}
2850 	}
2851 
2852 exit_thread:
2853 	/*
2854 	 * It looks like the request list is empty, but we need
2855 	 * to check it under the li_list_mtx lock, to prevent any
2856 	 * additions into it, and of course we should lock ext4_li_mtx
2857 	 * to atomically free the list and ext4_li_info, because at
2858 	 * this point another ext4 filesystem could be registering
2859 	 * new one.
2860 	 */
2861 	mutex_lock(&ext4_li_mtx);
2862 	mutex_lock(&eli->li_list_mtx);
2863 	if (!list_empty(&eli->li_request_list)) {
2864 		mutex_unlock(&eli->li_list_mtx);
2865 		mutex_unlock(&ext4_li_mtx);
2866 		goto cont_thread;
2867 	}
2868 	mutex_unlock(&eli->li_list_mtx);
2869 	kfree(ext4_li_info);
2870 	ext4_li_info = NULL;
2871 	mutex_unlock(&ext4_li_mtx);
2872 
2873 	return 0;
2874 }
2875 
2876 static void ext4_clear_request_list(void)
2877 {
2878 	struct list_head *pos, *n;
2879 	struct ext4_li_request *elr;
2880 
2881 	mutex_lock(&ext4_li_info->li_list_mtx);
2882 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2883 		elr = list_entry(pos, struct ext4_li_request,
2884 				 lr_request);
2885 		ext4_remove_li_request(elr);
2886 	}
2887 	mutex_unlock(&ext4_li_info->li_list_mtx);
2888 }
2889 
2890 static int ext4_run_lazyinit_thread(void)
2891 {
2892 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2893 					 ext4_li_info, "ext4lazyinit");
2894 	if (IS_ERR(ext4_lazyinit_task)) {
2895 		int err = PTR_ERR(ext4_lazyinit_task);
2896 		ext4_clear_request_list();
2897 		kfree(ext4_li_info);
2898 		ext4_li_info = NULL;
2899 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2900 				 "initialization thread\n",
2901 				 err);
2902 		return err;
2903 	}
2904 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2905 	return 0;
2906 }
2907 
2908 /*
2909  * Check whether it make sense to run itable init. thread or not.
2910  * If there is at least one uninitialized inode table, return
2911  * corresponding group number, else the loop goes through all
2912  * groups and return total number of groups.
2913  */
2914 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2915 {
2916 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2917 	struct ext4_group_desc *gdp = NULL;
2918 
2919 	for (group = 0; group < ngroups; group++) {
2920 		gdp = ext4_get_group_desc(sb, group, NULL);
2921 		if (!gdp)
2922 			continue;
2923 
2924 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2925 			break;
2926 	}
2927 
2928 	return group;
2929 }
2930 
2931 static int ext4_li_info_new(void)
2932 {
2933 	struct ext4_lazy_init *eli = NULL;
2934 
2935 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2936 	if (!eli)
2937 		return -ENOMEM;
2938 
2939 	INIT_LIST_HEAD(&eli->li_request_list);
2940 	mutex_init(&eli->li_list_mtx);
2941 
2942 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2943 
2944 	ext4_li_info = eli;
2945 
2946 	return 0;
2947 }
2948 
2949 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2950 					    ext4_group_t start)
2951 {
2952 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2953 	struct ext4_li_request *elr;
2954 	unsigned long rnd;
2955 
2956 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2957 	if (!elr)
2958 		return NULL;
2959 
2960 	elr->lr_super = sb;
2961 	elr->lr_sbi = sbi;
2962 	elr->lr_next_group = start;
2963 
2964 	/*
2965 	 * Randomize first schedule time of the request to
2966 	 * spread the inode table initialization requests
2967 	 * better.
2968 	 */
2969 	get_random_bytes(&rnd, sizeof(rnd));
2970 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
2971 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2972 
2973 	return elr;
2974 }
2975 
2976 static int ext4_register_li_request(struct super_block *sb,
2977 				    ext4_group_t first_not_zeroed)
2978 {
2979 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2980 	struct ext4_li_request *elr;
2981 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2982 	int ret = 0;
2983 
2984 	if (sbi->s_li_request != NULL) {
2985 		/*
2986 		 * Reset timeout so it can be computed again, because
2987 		 * s_li_wait_mult might have changed.
2988 		 */
2989 		sbi->s_li_request->lr_timeout = 0;
2990 		return 0;
2991 	}
2992 
2993 	if (first_not_zeroed == ngroups ||
2994 	    (sb->s_flags & MS_RDONLY) ||
2995 	    !test_opt(sb, INIT_INODE_TABLE))
2996 		return 0;
2997 
2998 	elr = ext4_li_request_new(sb, first_not_zeroed);
2999 	if (!elr)
3000 		return -ENOMEM;
3001 
3002 	mutex_lock(&ext4_li_mtx);
3003 
3004 	if (NULL == ext4_li_info) {
3005 		ret = ext4_li_info_new();
3006 		if (ret)
3007 			goto out;
3008 	}
3009 
3010 	mutex_lock(&ext4_li_info->li_list_mtx);
3011 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3012 	mutex_unlock(&ext4_li_info->li_list_mtx);
3013 
3014 	sbi->s_li_request = elr;
3015 	/*
3016 	 * set elr to NULL here since it has been inserted to
3017 	 * the request_list and the removal and free of it is
3018 	 * handled by ext4_clear_request_list from now on.
3019 	 */
3020 	elr = NULL;
3021 
3022 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3023 		ret = ext4_run_lazyinit_thread();
3024 		if (ret)
3025 			goto out;
3026 	}
3027 out:
3028 	mutex_unlock(&ext4_li_mtx);
3029 	if (ret)
3030 		kfree(elr);
3031 	return ret;
3032 }
3033 
3034 /*
3035  * We do not need to lock anything since this is called on
3036  * module unload.
3037  */
3038 static void ext4_destroy_lazyinit_thread(void)
3039 {
3040 	/*
3041 	 * If thread exited earlier
3042 	 * there's nothing to be done.
3043 	 */
3044 	if (!ext4_li_info || !ext4_lazyinit_task)
3045 		return;
3046 
3047 	kthread_stop(ext4_lazyinit_task);
3048 }
3049 
3050 static int set_journal_csum_feature_set(struct super_block *sb)
3051 {
3052 	int ret = 1;
3053 	int compat, incompat;
3054 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3055 
3056 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3057 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3058 		/* journal checksum v2 */
3059 		compat = 0;
3060 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3061 	} else {
3062 		/* journal checksum v1 */
3063 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3064 		incompat = 0;
3065 	}
3066 
3067 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3068 		ret = jbd2_journal_set_features(sbi->s_journal,
3069 				compat, 0,
3070 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3071 				incompat);
3072 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3073 		ret = jbd2_journal_set_features(sbi->s_journal,
3074 				compat, 0,
3075 				incompat);
3076 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3077 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3078 	} else {
3079 		jbd2_journal_clear_features(sbi->s_journal,
3080 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3081 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3082 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3083 	}
3084 
3085 	return ret;
3086 }
3087 
3088 /*
3089  * Note: calculating the overhead so we can be compatible with
3090  * historical BSD practice is quite difficult in the face of
3091  * clusters/bigalloc.  This is because multiple metadata blocks from
3092  * different block group can end up in the same allocation cluster.
3093  * Calculating the exact overhead in the face of clustered allocation
3094  * requires either O(all block bitmaps) in memory or O(number of block
3095  * groups**2) in time.  We will still calculate the superblock for
3096  * older file systems --- and if we come across with a bigalloc file
3097  * system with zero in s_overhead_clusters the estimate will be close to
3098  * correct especially for very large cluster sizes --- but for newer
3099  * file systems, it's better to calculate this figure once at mkfs
3100  * time, and store it in the superblock.  If the superblock value is
3101  * present (even for non-bigalloc file systems), we will use it.
3102  */
3103 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3104 			  char *buf)
3105 {
3106 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3107 	struct ext4_group_desc	*gdp;
3108 	ext4_fsblk_t		first_block, last_block, b;
3109 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3110 	int			s, j, count = 0;
3111 
3112 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3113 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3114 			sbi->s_itb_per_group + 2);
3115 
3116 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3117 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3118 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3119 	for (i = 0; i < ngroups; i++) {
3120 		gdp = ext4_get_group_desc(sb, i, NULL);
3121 		b = ext4_block_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_bitmap(sb, gdp);
3127 		if (b >= first_block && b <= last_block) {
3128 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3129 			count++;
3130 		}
3131 		b = ext4_inode_table(sb, gdp);
3132 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3133 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3134 				int c = EXT4_B2C(sbi, b - first_block);
3135 				ext4_set_bit(c, buf);
3136 				count++;
3137 			}
3138 		if (i != grp)
3139 			continue;
3140 		s = 0;
3141 		if (ext4_bg_has_super(sb, grp)) {
3142 			ext4_set_bit(s++, buf);
3143 			count++;
3144 		}
3145 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3146 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3147 			count++;
3148 		}
3149 	}
3150 	if (!count)
3151 		return 0;
3152 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3153 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3154 }
3155 
3156 /*
3157  * Compute the overhead and stash it in sbi->s_overhead
3158  */
3159 int ext4_calculate_overhead(struct super_block *sb)
3160 {
3161 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3162 	struct ext4_super_block *es = sbi->s_es;
3163 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3164 	ext4_fsblk_t overhead = 0;
3165 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3166 
3167 	memset(buf, 0, PAGE_SIZE);
3168 	if (!buf)
3169 		return -ENOMEM;
3170 
3171 	/*
3172 	 * Compute the overhead (FS structures).  This is constant
3173 	 * for a given filesystem unless the number of block groups
3174 	 * changes so we cache the previous value until it does.
3175 	 */
3176 
3177 	/*
3178 	 * All of the blocks before first_data_block are overhead
3179 	 */
3180 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3181 
3182 	/*
3183 	 * Add the overhead found in each block group
3184 	 */
3185 	for (i = 0; i < ngroups; i++) {
3186 		int blks;
3187 
3188 		blks = count_overhead(sb, i, buf);
3189 		overhead += blks;
3190 		if (blks)
3191 			memset(buf, 0, PAGE_SIZE);
3192 		cond_resched();
3193 	}
3194 	sbi->s_overhead = overhead;
3195 	smp_wmb();
3196 	free_page((unsigned long) buf);
3197 	return 0;
3198 }
3199 
3200 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3201 {
3202 	char *orig_data = kstrdup(data, GFP_KERNEL);
3203 	struct buffer_head *bh;
3204 	struct ext4_super_block *es = NULL;
3205 	struct ext4_sb_info *sbi;
3206 	ext4_fsblk_t block;
3207 	ext4_fsblk_t sb_block = get_sb_block(&data);
3208 	ext4_fsblk_t logical_sb_block;
3209 	unsigned long offset = 0;
3210 	unsigned long journal_devnum = 0;
3211 	unsigned long def_mount_opts;
3212 	struct inode *root;
3213 	char *cp;
3214 	const char *descr;
3215 	int ret = -ENOMEM;
3216 	int blocksize, clustersize;
3217 	unsigned int db_count;
3218 	unsigned int i;
3219 	int needs_recovery, has_huge_files, has_bigalloc;
3220 	__u64 blocks_count;
3221 	int err;
3222 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3223 	ext4_group_t first_not_zeroed;
3224 
3225 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3226 	if (!sbi)
3227 		goto out_free_orig;
3228 
3229 	sbi->s_blockgroup_lock =
3230 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3231 	if (!sbi->s_blockgroup_lock) {
3232 		kfree(sbi);
3233 		goto out_free_orig;
3234 	}
3235 	sb->s_fs_info = sbi;
3236 	sbi->s_sb = sb;
3237 	sbi->s_mount_opt = 0;
3238 	sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
3239 	sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
3240 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3241 	sbi->s_sb_block = sb_block;
3242 	if (sb->s_bdev->bd_part)
3243 		sbi->s_sectors_written_start =
3244 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3245 
3246 	/* Cleanup superblock name */
3247 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3248 		*cp = '!';
3249 
3250 	ret = -EINVAL;
3251 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3252 	if (!blocksize) {
3253 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3254 		goto out_fail;
3255 	}
3256 
3257 	/*
3258 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3259 	 * block sizes.  We need to calculate the offset from buffer start.
3260 	 */
3261 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3262 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3263 		offset = do_div(logical_sb_block, blocksize);
3264 	} else {
3265 		logical_sb_block = sb_block;
3266 	}
3267 
3268 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3269 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3270 		goto out_fail;
3271 	}
3272 	/*
3273 	 * Note: s_es must be initialized as soon as possible because
3274 	 *       some ext4 macro-instructions depend on its value
3275 	 */
3276 	es = (struct ext4_super_block *) (bh->b_data + offset);
3277 	sbi->s_es = es;
3278 	sb->s_magic = le16_to_cpu(es->s_magic);
3279 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3280 		goto cantfind_ext4;
3281 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3282 
3283 	/* Warn if metadata_csum and gdt_csum are both set. */
3284 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3285 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3286 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3287 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3288 			     "redundant flags; please run fsck.");
3289 
3290 	/* Check for a known checksum algorithm */
3291 	if (!ext4_verify_csum_type(sb, es)) {
3292 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3293 			 "unknown checksum algorithm.");
3294 		silent = 1;
3295 		goto cantfind_ext4;
3296 	}
3297 
3298 	/* Load the checksum driver */
3299 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3300 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3301 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3302 		if (IS_ERR(sbi->s_chksum_driver)) {
3303 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3304 			ret = PTR_ERR(sbi->s_chksum_driver);
3305 			sbi->s_chksum_driver = NULL;
3306 			goto failed_mount;
3307 		}
3308 	}
3309 
3310 	/* Check superblock checksum */
3311 	if (!ext4_superblock_csum_verify(sb, es)) {
3312 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3313 			 "invalid superblock checksum.  Run e2fsck?");
3314 		silent = 1;
3315 		goto cantfind_ext4;
3316 	}
3317 
3318 	/* Precompute checksum seed for all metadata */
3319 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3320 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3321 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3322 					       sizeof(es->s_uuid));
3323 
3324 	/* Set defaults before we parse the mount options */
3325 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3326 	set_opt(sb, INIT_INODE_TABLE);
3327 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3328 		set_opt(sb, DEBUG);
3329 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3330 		set_opt(sb, GRPID);
3331 	if (def_mount_opts & EXT4_DEFM_UID16)
3332 		set_opt(sb, NO_UID32);
3333 	/* xattr user namespace & acls are now defaulted on */
3334 #ifdef CONFIG_EXT4_FS_XATTR
3335 	set_opt(sb, XATTR_USER);
3336 #endif
3337 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3338 	set_opt(sb, POSIX_ACL);
3339 #endif
3340 	set_opt(sb, MBLK_IO_SUBMIT);
3341 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3342 		set_opt(sb, JOURNAL_DATA);
3343 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3344 		set_opt(sb, ORDERED_DATA);
3345 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3346 		set_opt(sb, WRITEBACK_DATA);
3347 
3348 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3349 		set_opt(sb, ERRORS_PANIC);
3350 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3351 		set_opt(sb, ERRORS_CONT);
3352 	else
3353 		set_opt(sb, ERRORS_RO);
3354 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3355 		set_opt(sb, BLOCK_VALIDITY);
3356 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3357 		set_opt(sb, DISCARD);
3358 
3359 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3360 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3361 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3362 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3363 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3364 
3365 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3366 		set_opt(sb, BARRIER);
3367 
3368 	/*
3369 	 * enable delayed allocation by default
3370 	 * Use -o nodelalloc to turn it off
3371 	 */
3372 	if (!IS_EXT3_SB(sb) &&
3373 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3374 		set_opt(sb, DELALLOC);
3375 
3376 	/*
3377 	 * set default s_li_wait_mult for lazyinit, for the case there is
3378 	 * no mount option specified.
3379 	 */
3380 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3381 
3382 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3383 			   &journal_devnum, &journal_ioprio, 0)) {
3384 		ext4_msg(sb, KERN_WARNING,
3385 			 "failed to parse options in superblock: %s",
3386 			 sbi->s_es->s_mount_opts);
3387 	}
3388 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3389 	if (!parse_options((char *) data, sb, &journal_devnum,
3390 			   &journal_ioprio, 0))
3391 		goto failed_mount;
3392 
3393 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3394 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3395 			    "with data=journal disables delayed "
3396 			    "allocation and O_DIRECT support!\n");
3397 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
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, DIOREAD_NOLOCK)) {
3403 			ext4_msg(sb, KERN_ERR, "can't mount with "
3404 				 "both data=journal and delalloc");
3405 			goto failed_mount;
3406 		}
3407 		if (test_opt(sb, DELALLOC))
3408 			clear_opt(sb, DELALLOC);
3409 	}
3410 
3411 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3412 	if (test_opt(sb, DIOREAD_NOLOCK)) {
3413 		if (blocksize < PAGE_SIZE) {
3414 			ext4_msg(sb, KERN_ERR, "can't mount with "
3415 				 "dioread_nolock if block size != PAGE_SIZE");
3416 			goto failed_mount;
3417 		}
3418 	}
3419 
3420 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3421 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3422 
3423 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3424 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3425 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3426 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3427 		ext4_msg(sb, KERN_WARNING,
3428 		       "feature flags set on rev 0 fs, "
3429 		       "running e2fsck is recommended");
3430 
3431 	if (IS_EXT2_SB(sb)) {
3432 		if (ext2_feature_set_ok(sb))
3433 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3434 				 "using the ext4 subsystem");
3435 		else {
3436 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3437 				 "to feature incompatibilities");
3438 			goto failed_mount;
3439 		}
3440 	}
3441 
3442 	if (IS_EXT3_SB(sb)) {
3443 		if (ext3_feature_set_ok(sb))
3444 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3445 				 "using the ext4 subsystem");
3446 		else {
3447 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3448 				 "to feature incompatibilities");
3449 			goto failed_mount;
3450 		}
3451 	}
3452 
3453 	/*
3454 	 * Check feature flags regardless of the revision level, since we
3455 	 * previously didn't change the revision level when setting the flags,
3456 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3457 	 */
3458 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3459 		goto failed_mount;
3460 
3461 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3462 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3463 		ext4_msg(sb, KERN_ERR,
3464 		       "Unsupported filesystem blocksize %d", blocksize);
3465 		goto failed_mount;
3466 	}
3467 
3468 	if (sb->s_blocksize != blocksize) {
3469 		/* Validate the filesystem blocksize */
3470 		if (!sb_set_blocksize(sb, blocksize)) {
3471 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3472 					blocksize);
3473 			goto failed_mount;
3474 		}
3475 
3476 		brelse(bh);
3477 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3478 		offset = do_div(logical_sb_block, blocksize);
3479 		bh = sb_bread(sb, logical_sb_block);
3480 		if (!bh) {
3481 			ext4_msg(sb, KERN_ERR,
3482 			       "Can't read superblock on 2nd try");
3483 			goto failed_mount;
3484 		}
3485 		es = (struct ext4_super_block *)(bh->b_data + offset);
3486 		sbi->s_es = es;
3487 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3488 			ext4_msg(sb, KERN_ERR,
3489 			       "Magic mismatch, very weird!");
3490 			goto failed_mount;
3491 		}
3492 	}
3493 
3494 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3495 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3496 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3497 						      has_huge_files);
3498 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3499 
3500 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3501 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3502 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3503 	} else {
3504 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3505 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3506 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3507 		    (!is_power_of_2(sbi->s_inode_size)) ||
3508 		    (sbi->s_inode_size > blocksize)) {
3509 			ext4_msg(sb, KERN_ERR,
3510 			       "unsupported inode size: %d",
3511 			       sbi->s_inode_size);
3512 			goto failed_mount;
3513 		}
3514 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3515 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3516 	}
3517 
3518 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3519 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3520 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3521 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3522 		    !is_power_of_2(sbi->s_desc_size)) {
3523 			ext4_msg(sb, KERN_ERR,
3524 			       "unsupported descriptor size %lu",
3525 			       sbi->s_desc_size);
3526 			goto failed_mount;
3527 		}
3528 	} else
3529 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3530 
3531 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3532 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3533 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3534 		goto cantfind_ext4;
3535 
3536 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3537 	if (sbi->s_inodes_per_block == 0)
3538 		goto cantfind_ext4;
3539 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3540 					sbi->s_inodes_per_block;
3541 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3542 	sbi->s_sbh = bh;
3543 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3544 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3545 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3546 
3547 	for (i = 0; i < 4; i++)
3548 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3549 	sbi->s_def_hash_version = es->s_def_hash_version;
3550 	i = le32_to_cpu(es->s_flags);
3551 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3552 		sbi->s_hash_unsigned = 3;
3553 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3554 #ifdef __CHAR_UNSIGNED__
3555 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3556 		sbi->s_hash_unsigned = 3;
3557 #else
3558 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3559 #endif
3560 	}
3561 
3562 	/* Handle clustersize */
3563 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3564 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3565 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3566 	if (has_bigalloc) {
3567 		if (clustersize < blocksize) {
3568 			ext4_msg(sb, KERN_ERR,
3569 				 "cluster size (%d) smaller than "
3570 				 "block size (%d)", clustersize, blocksize);
3571 			goto failed_mount;
3572 		}
3573 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3574 			le32_to_cpu(es->s_log_block_size);
3575 		sbi->s_clusters_per_group =
3576 			le32_to_cpu(es->s_clusters_per_group);
3577 		if (sbi->s_clusters_per_group > blocksize * 8) {
3578 			ext4_msg(sb, KERN_ERR,
3579 				 "#clusters per group too big: %lu",
3580 				 sbi->s_clusters_per_group);
3581 			goto failed_mount;
3582 		}
3583 		if (sbi->s_blocks_per_group !=
3584 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3585 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3586 				 "clusters per group (%lu) inconsistent",
3587 				 sbi->s_blocks_per_group,
3588 				 sbi->s_clusters_per_group);
3589 			goto failed_mount;
3590 		}
3591 	} else {
3592 		if (clustersize != blocksize) {
3593 			ext4_warning(sb, "fragment/cluster size (%d) != "
3594 				     "block size (%d)", clustersize,
3595 				     blocksize);
3596 			clustersize = blocksize;
3597 		}
3598 		if (sbi->s_blocks_per_group > blocksize * 8) {
3599 			ext4_msg(sb, KERN_ERR,
3600 				 "#blocks per group too big: %lu",
3601 				 sbi->s_blocks_per_group);
3602 			goto failed_mount;
3603 		}
3604 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3605 		sbi->s_cluster_bits = 0;
3606 	}
3607 	sbi->s_cluster_ratio = clustersize / blocksize;
3608 
3609 	if (sbi->s_inodes_per_group > blocksize * 8) {
3610 		ext4_msg(sb, KERN_ERR,
3611 		       "#inodes per group too big: %lu",
3612 		       sbi->s_inodes_per_group);
3613 		goto failed_mount;
3614 	}
3615 
3616 	/*
3617 	 * Test whether we have more sectors than will fit in sector_t,
3618 	 * and whether the max offset is addressable by the page cache.
3619 	 */
3620 	err = generic_check_addressable(sb->s_blocksize_bits,
3621 					ext4_blocks_count(es));
3622 	if (err) {
3623 		ext4_msg(sb, KERN_ERR, "filesystem"
3624 			 " too large to mount safely on this system");
3625 		if (sizeof(sector_t) < 8)
3626 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3627 		ret = err;
3628 		goto failed_mount;
3629 	}
3630 
3631 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3632 		goto cantfind_ext4;
3633 
3634 	/* check blocks count against device size */
3635 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3636 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3637 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3638 		       "exceeds size of device (%llu blocks)",
3639 		       ext4_blocks_count(es), blocks_count);
3640 		goto failed_mount;
3641 	}
3642 
3643 	/*
3644 	 * It makes no sense for the first data block to be beyond the end
3645 	 * of the filesystem.
3646 	 */
3647 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3648 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3649 			 "block %u is beyond end of filesystem (%llu)",
3650 			 le32_to_cpu(es->s_first_data_block),
3651 			 ext4_blocks_count(es));
3652 		goto failed_mount;
3653 	}
3654 	blocks_count = (ext4_blocks_count(es) -
3655 			le32_to_cpu(es->s_first_data_block) +
3656 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3657 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3658 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3659 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3660 		       "(block count %llu, first data block %u, "
3661 		       "blocks per group %lu)", sbi->s_groups_count,
3662 		       ext4_blocks_count(es),
3663 		       le32_to_cpu(es->s_first_data_block),
3664 		       EXT4_BLOCKS_PER_GROUP(sb));
3665 		goto failed_mount;
3666 	}
3667 	sbi->s_groups_count = blocks_count;
3668 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3669 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3670 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3671 		   EXT4_DESC_PER_BLOCK(sb);
3672 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3673 					  sizeof(struct buffer_head *),
3674 					  GFP_KERNEL);
3675 	if (sbi->s_group_desc == NULL) {
3676 		ext4_msg(sb, KERN_ERR, "not enough memory");
3677 		ret = -ENOMEM;
3678 		goto failed_mount;
3679 	}
3680 
3681 	if (ext4_proc_root)
3682 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3683 
3684 	if (sbi->s_proc)
3685 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3686 				 &ext4_seq_options_fops, sb);
3687 
3688 	bgl_lock_init(sbi->s_blockgroup_lock);
3689 
3690 	for (i = 0; i < db_count; i++) {
3691 		block = descriptor_loc(sb, logical_sb_block, i);
3692 		sbi->s_group_desc[i] = sb_bread(sb, block);
3693 		if (!sbi->s_group_desc[i]) {
3694 			ext4_msg(sb, KERN_ERR,
3695 			       "can't read group descriptor %d", i);
3696 			db_count = i;
3697 			goto failed_mount2;
3698 		}
3699 	}
3700 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3701 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3702 		goto failed_mount2;
3703 	}
3704 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3705 		if (!ext4_fill_flex_info(sb)) {
3706 			ext4_msg(sb, KERN_ERR,
3707 			       "unable to initialize "
3708 			       "flex_bg meta info!");
3709 			goto failed_mount2;
3710 		}
3711 
3712 	sbi->s_gdb_count = db_count;
3713 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3714 	spin_lock_init(&sbi->s_next_gen_lock);
3715 
3716 	init_timer(&sbi->s_err_report);
3717 	sbi->s_err_report.function = print_daily_error_info;
3718 	sbi->s_err_report.data = (unsigned long) sb;
3719 
3720 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3721 			ext4_count_free_clusters(sb));
3722 	if (!err) {
3723 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3724 				ext4_count_free_inodes(sb));
3725 	}
3726 	if (!err) {
3727 		err = percpu_counter_init(&sbi->s_dirs_counter,
3728 				ext4_count_dirs(sb));
3729 	}
3730 	if (!err) {
3731 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3732 	}
3733 	if (err) {
3734 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3735 		ret = err;
3736 		goto failed_mount3;
3737 	}
3738 
3739 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3740 	sbi->s_max_writeback_mb_bump = 128;
3741 
3742 	/*
3743 	 * set up enough so that it can read an inode
3744 	 */
3745 	if (!test_opt(sb, NOLOAD) &&
3746 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3747 		sb->s_op = &ext4_sops;
3748 	else
3749 		sb->s_op = &ext4_nojournal_sops;
3750 	sb->s_export_op = &ext4_export_ops;
3751 	sb->s_xattr = ext4_xattr_handlers;
3752 #ifdef CONFIG_QUOTA
3753 	sb->s_qcop = &ext4_qctl_operations;
3754 	sb->dq_op = &ext4_quota_operations;
3755 
3756 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
3757 		/* Use qctl operations for hidden quota files. */
3758 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3759 	}
3760 #endif
3761 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3762 
3763 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3764 	mutex_init(&sbi->s_orphan_lock);
3765 	sbi->s_resize_flags = 0;
3766 
3767 	sb->s_root = NULL;
3768 
3769 	needs_recovery = (es->s_last_orphan != 0 ||
3770 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3771 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3772 
3773 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3774 	    !(sb->s_flags & MS_RDONLY))
3775 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3776 			goto failed_mount3;
3777 
3778 	/*
3779 	 * The first inode we look at is the journal inode.  Don't try
3780 	 * root first: it may be modified in the journal!
3781 	 */
3782 	if (!test_opt(sb, NOLOAD) &&
3783 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3784 		if (ext4_load_journal(sb, es, journal_devnum))
3785 			goto failed_mount3;
3786 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3787 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3788 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3789 		       "suppressed and not mounted read-only");
3790 		goto failed_mount_wq;
3791 	} else {
3792 		clear_opt(sb, DATA_FLAGS);
3793 		sbi->s_journal = NULL;
3794 		needs_recovery = 0;
3795 		goto no_journal;
3796 	}
3797 
3798 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3799 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3800 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3801 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3802 		goto failed_mount_wq;
3803 	}
3804 
3805 	if (!set_journal_csum_feature_set(sb)) {
3806 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3807 			 "feature set");
3808 		goto failed_mount_wq;
3809 	}
3810 
3811 	/* We have now updated the journal if required, so we can
3812 	 * validate the data journaling mode. */
3813 	switch (test_opt(sb, DATA_FLAGS)) {
3814 	case 0:
3815 		/* No mode set, assume a default based on the journal
3816 		 * capabilities: ORDERED_DATA if the journal can
3817 		 * cope, else JOURNAL_DATA
3818 		 */
3819 		if (jbd2_journal_check_available_features
3820 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3821 			set_opt(sb, ORDERED_DATA);
3822 		else
3823 			set_opt(sb, JOURNAL_DATA);
3824 		break;
3825 
3826 	case EXT4_MOUNT_ORDERED_DATA:
3827 	case EXT4_MOUNT_WRITEBACK_DATA:
3828 		if (!jbd2_journal_check_available_features
3829 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3830 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3831 			       "requested data journaling mode");
3832 			goto failed_mount_wq;
3833 		}
3834 	default:
3835 		break;
3836 	}
3837 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3838 
3839 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3840 
3841 	/*
3842 	 * The journal may have updated the bg summary counts, so we
3843 	 * need to update the global counters.
3844 	 */
3845 	percpu_counter_set(&sbi->s_freeclusters_counter,
3846 			   ext4_count_free_clusters(sb));
3847 	percpu_counter_set(&sbi->s_freeinodes_counter,
3848 			   ext4_count_free_inodes(sb));
3849 	percpu_counter_set(&sbi->s_dirs_counter,
3850 			   ext4_count_dirs(sb));
3851 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3852 
3853 no_journal:
3854 	/*
3855 	 * Get the # of file system overhead blocks from the
3856 	 * superblock if present.
3857 	 */
3858 	if (es->s_overhead_clusters)
3859 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3860 	else {
3861 		ret = ext4_calculate_overhead(sb);
3862 		if (ret)
3863 			goto failed_mount_wq;
3864 	}
3865 
3866 	/*
3867 	 * The maximum number of concurrent works can be high and
3868 	 * concurrency isn't really necessary.  Limit it to 1.
3869 	 */
3870 	EXT4_SB(sb)->dio_unwritten_wq =
3871 		alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3872 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3873 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3874 		goto failed_mount_wq;
3875 	}
3876 
3877 	/*
3878 	 * The jbd2_journal_load will have done any necessary log recovery,
3879 	 * so we can safely mount the rest of the filesystem now.
3880 	 */
3881 
3882 	root = ext4_iget(sb, EXT4_ROOT_INO);
3883 	if (IS_ERR(root)) {
3884 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3885 		ret = PTR_ERR(root);
3886 		root = NULL;
3887 		goto failed_mount4;
3888 	}
3889 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3890 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3891 		iput(root);
3892 		goto failed_mount4;
3893 	}
3894 	sb->s_root = d_make_root(root);
3895 	if (!sb->s_root) {
3896 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3897 		ret = -ENOMEM;
3898 		goto failed_mount4;
3899 	}
3900 
3901 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3902 		sb->s_flags |= MS_RDONLY;
3903 
3904 	/* determine the minimum size of new large inodes, if present */
3905 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3906 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3907 						     EXT4_GOOD_OLD_INODE_SIZE;
3908 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3909 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3910 			if (sbi->s_want_extra_isize <
3911 			    le16_to_cpu(es->s_want_extra_isize))
3912 				sbi->s_want_extra_isize =
3913 					le16_to_cpu(es->s_want_extra_isize);
3914 			if (sbi->s_want_extra_isize <
3915 			    le16_to_cpu(es->s_min_extra_isize))
3916 				sbi->s_want_extra_isize =
3917 					le16_to_cpu(es->s_min_extra_isize);
3918 		}
3919 	}
3920 	/* Check if enough inode space is available */
3921 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3922 							sbi->s_inode_size) {
3923 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3924 						       EXT4_GOOD_OLD_INODE_SIZE;
3925 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3926 			 "available");
3927 	}
3928 
3929 	err = ext4_setup_system_zone(sb);
3930 	if (err) {
3931 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3932 			 "zone (%d)", err);
3933 		goto failed_mount4a;
3934 	}
3935 
3936 	ext4_ext_init(sb);
3937 	err = ext4_mb_init(sb);
3938 	if (err) {
3939 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3940 			 err);
3941 		goto failed_mount5;
3942 	}
3943 
3944 	err = ext4_register_li_request(sb, first_not_zeroed);
3945 	if (err)
3946 		goto failed_mount6;
3947 
3948 	sbi->s_kobj.kset = ext4_kset;
3949 	init_completion(&sbi->s_kobj_unregister);
3950 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3951 				   "%s", sb->s_id);
3952 	if (err)
3953 		goto failed_mount7;
3954 
3955 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3956 	ext4_orphan_cleanup(sb, es);
3957 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3958 	if (needs_recovery) {
3959 		ext4_msg(sb, KERN_INFO, "recovery complete");
3960 		ext4_mark_recovery_complete(sb, es);
3961 	}
3962 	if (EXT4_SB(sb)->s_journal) {
3963 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3964 			descr = " journalled data mode";
3965 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3966 			descr = " ordered data mode";
3967 		else
3968 			descr = " writeback data mode";
3969 	} else
3970 		descr = "out journal";
3971 
3972 #ifdef CONFIG_QUOTA
3973 	/* Enable quota usage during mount. */
3974 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
3975 	    !(sb->s_flags & MS_RDONLY)) {
3976 		ret = ext4_enable_quotas(sb);
3977 		if (ret)
3978 			goto failed_mount7;
3979 	}
3980 #endif  /* CONFIG_QUOTA */
3981 
3982 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3983 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3984 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3985 
3986 	if (es->s_error_count)
3987 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3988 
3989 	kfree(orig_data);
3990 	return 0;
3991 
3992 cantfind_ext4:
3993 	if (!silent)
3994 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3995 	goto failed_mount;
3996 
3997 failed_mount7:
3998 	ext4_unregister_li_request(sb);
3999 failed_mount6:
4000 	ext4_mb_release(sb);
4001 failed_mount5:
4002 	ext4_ext_release(sb);
4003 	ext4_release_system_zone(sb);
4004 failed_mount4a:
4005 	dput(sb->s_root);
4006 	sb->s_root = NULL;
4007 failed_mount4:
4008 	ext4_msg(sb, KERN_ERR, "mount failed");
4009 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4010 failed_mount_wq:
4011 	if (sbi->s_journal) {
4012 		jbd2_journal_destroy(sbi->s_journal);
4013 		sbi->s_journal = NULL;
4014 	}
4015 failed_mount3:
4016 	del_timer(&sbi->s_err_report);
4017 	if (sbi->s_flex_groups)
4018 		ext4_kvfree(sbi->s_flex_groups);
4019 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4020 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4021 	percpu_counter_destroy(&sbi->s_dirs_counter);
4022 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4023 	if (sbi->s_mmp_tsk)
4024 		kthread_stop(sbi->s_mmp_tsk);
4025 failed_mount2:
4026 	for (i = 0; i < db_count; i++)
4027 		brelse(sbi->s_group_desc[i]);
4028 	ext4_kvfree(sbi->s_group_desc);
4029 failed_mount:
4030 	if (sbi->s_chksum_driver)
4031 		crypto_free_shash(sbi->s_chksum_driver);
4032 	if (sbi->s_proc) {
4033 		remove_proc_entry("options", sbi->s_proc);
4034 		remove_proc_entry(sb->s_id, ext4_proc_root);
4035 	}
4036 #ifdef CONFIG_QUOTA
4037 	for (i = 0; i < MAXQUOTAS; i++)
4038 		kfree(sbi->s_qf_names[i]);
4039 #endif
4040 	ext4_blkdev_remove(sbi);
4041 	brelse(bh);
4042 out_fail:
4043 	sb->s_fs_info = NULL;
4044 	kfree(sbi->s_blockgroup_lock);
4045 	kfree(sbi);
4046 out_free_orig:
4047 	kfree(orig_data);
4048 	return ret;
4049 }
4050 
4051 /*
4052  * Setup any per-fs journal parameters now.  We'll do this both on
4053  * initial mount, once the journal has been initialised but before we've
4054  * done any recovery; and again on any subsequent remount.
4055  */
4056 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4057 {
4058 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4059 
4060 	journal->j_commit_interval = sbi->s_commit_interval;
4061 	journal->j_min_batch_time = sbi->s_min_batch_time;
4062 	journal->j_max_batch_time = sbi->s_max_batch_time;
4063 
4064 	write_lock(&journal->j_state_lock);
4065 	if (test_opt(sb, BARRIER))
4066 		journal->j_flags |= JBD2_BARRIER;
4067 	else
4068 		journal->j_flags &= ~JBD2_BARRIER;
4069 	if (test_opt(sb, DATA_ERR_ABORT))
4070 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4071 	else
4072 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4073 	write_unlock(&journal->j_state_lock);
4074 }
4075 
4076 static journal_t *ext4_get_journal(struct super_block *sb,
4077 				   unsigned int journal_inum)
4078 {
4079 	struct inode *journal_inode;
4080 	journal_t *journal;
4081 
4082 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4083 
4084 	/* First, test for the existence of a valid inode on disk.  Bad
4085 	 * things happen if we iget() an unused inode, as the subsequent
4086 	 * iput() will try to delete it. */
4087 
4088 	journal_inode = ext4_iget(sb, journal_inum);
4089 	if (IS_ERR(journal_inode)) {
4090 		ext4_msg(sb, KERN_ERR, "no journal found");
4091 		return NULL;
4092 	}
4093 	if (!journal_inode->i_nlink) {
4094 		make_bad_inode(journal_inode);
4095 		iput(journal_inode);
4096 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4097 		return NULL;
4098 	}
4099 
4100 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4101 		  journal_inode, journal_inode->i_size);
4102 	if (!S_ISREG(journal_inode->i_mode)) {
4103 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4104 		iput(journal_inode);
4105 		return NULL;
4106 	}
4107 
4108 	journal = jbd2_journal_init_inode(journal_inode);
4109 	if (!journal) {
4110 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4111 		iput(journal_inode);
4112 		return NULL;
4113 	}
4114 	journal->j_private = sb;
4115 	ext4_init_journal_params(sb, journal);
4116 	return journal;
4117 }
4118 
4119 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4120 				       dev_t j_dev)
4121 {
4122 	struct buffer_head *bh;
4123 	journal_t *journal;
4124 	ext4_fsblk_t start;
4125 	ext4_fsblk_t len;
4126 	int hblock, blocksize;
4127 	ext4_fsblk_t sb_block;
4128 	unsigned long offset;
4129 	struct ext4_super_block *es;
4130 	struct block_device *bdev;
4131 
4132 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4133 
4134 	bdev = ext4_blkdev_get(j_dev, sb);
4135 	if (bdev == NULL)
4136 		return NULL;
4137 
4138 	blocksize = sb->s_blocksize;
4139 	hblock = bdev_logical_block_size(bdev);
4140 	if (blocksize < hblock) {
4141 		ext4_msg(sb, KERN_ERR,
4142 			"blocksize too small for journal device");
4143 		goto out_bdev;
4144 	}
4145 
4146 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4147 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4148 	set_blocksize(bdev, blocksize);
4149 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4150 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4151 		       "external journal");
4152 		goto out_bdev;
4153 	}
4154 
4155 	es = (struct ext4_super_block *) (bh->b_data + offset);
4156 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4157 	    !(le32_to_cpu(es->s_feature_incompat) &
4158 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4159 		ext4_msg(sb, KERN_ERR, "external journal has "
4160 					"bad superblock");
4161 		brelse(bh);
4162 		goto out_bdev;
4163 	}
4164 
4165 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4166 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4167 		brelse(bh);
4168 		goto out_bdev;
4169 	}
4170 
4171 	len = ext4_blocks_count(es);
4172 	start = sb_block + 1;
4173 	brelse(bh);	/* we're done with the superblock */
4174 
4175 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4176 					start, len, blocksize);
4177 	if (!journal) {
4178 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4179 		goto out_bdev;
4180 	}
4181 	journal->j_private = sb;
4182 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
4183 	wait_on_buffer(journal->j_sb_buffer);
4184 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4185 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4186 		goto out_journal;
4187 	}
4188 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4189 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4190 					"user (unsupported) - %d",
4191 			be32_to_cpu(journal->j_superblock->s_nr_users));
4192 		goto out_journal;
4193 	}
4194 	EXT4_SB(sb)->journal_bdev = bdev;
4195 	ext4_init_journal_params(sb, journal);
4196 	return journal;
4197 
4198 out_journal:
4199 	jbd2_journal_destroy(journal);
4200 out_bdev:
4201 	ext4_blkdev_put(bdev);
4202 	return NULL;
4203 }
4204 
4205 static int ext4_load_journal(struct super_block *sb,
4206 			     struct ext4_super_block *es,
4207 			     unsigned long journal_devnum)
4208 {
4209 	journal_t *journal;
4210 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4211 	dev_t journal_dev;
4212 	int err = 0;
4213 	int really_read_only;
4214 
4215 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4216 
4217 	if (journal_devnum &&
4218 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4219 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4220 			"numbers have changed");
4221 		journal_dev = new_decode_dev(journal_devnum);
4222 	} else
4223 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4224 
4225 	really_read_only = bdev_read_only(sb->s_bdev);
4226 
4227 	/*
4228 	 * Are we loading a blank journal or performing recovery after a
4229 	 * crash?  For recovery, we need to check in advance whether we
4230 	 * can get read-write access to the device.
4231 	 */
4232 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4233 		if (sb->s_flags & MS_RDONLY) {
4234 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4235 					"required on readonly filesystem");
4236 			if (really_read_only) {
4237 				ext4_msg(sb, KERN_ERR, "write access "
4238 					"unavailable, cannot proceed");
4239 				return -EROFS;
4240 			}
4241 			ext4_msg(sb, KERN_INFO, "write access will "
4242 			       "be enabled during recovery");
4243 		}
4244 	}
4245 
4246 	if (journal_inum && journal_dev) {
4247 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4248 		       "and inode journals!");
4249 		return -EINVAL;
4250 	}
4251 
4252 	if (journal_inum) {
4253 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4254 			return -EINVAL;
4255 	} else {
4256 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4257 			return -EINVAL;
4258 	}
4259 
4260 	if (!(journal->j_flags & JBD2_BARRIER))
4261 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4262 
4263 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4264 		err = jbd2_journal_wipe(journal, !really_read_only);
4265 	if (!err) {
4266 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4267 		if (save)
4268 			memcpy(save, ((char *) es) +
4269 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4270 		err = jbd2_journal_load(journal);
4271 		if (save)
4272 			memcpy(((char *) es) + EXT4_S_ERR_START,
4273 			       save, EXT4_S_ERR_LEN);
4274 		kfree(save);
4275 	}
4276 
4277 	if (err) {
4278 		ext4_msg(sb, KERN_ERR, "error loading journal");
4279 		jbd2_journal_destroy(journal);
4280 		return err;
4281 	}
4282 
4283 	EXT4_SB(sb)->s_journal = journal;
4284 	ext4_clear_journal_err(sb, es);
4285 
4286 	if (!really_read_only && journal_devnum &&
4287 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4288 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4289 
4290 		/* Make sure we flush the recovery flag to disk. */
4291 		ext4_commit_super(sb, 1);
4292 	}
4293 
4294 	return 0;
4295 }
4296 
4297 static int ext4_commit_super(struct super_block *sb, int sync)
4298 {
4299 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4300 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4301 	int error = 0;
4302 
4303 	if (!sbh || block_device_ejected(sb))
4304 		return error;
4305 	if (buffer_write_io_error(sbh)) {
4306 		/*
4307 		 * Oh, dear.  A previous attempt to write the
4308 		 * superblock failed.  This could happen because the
4309 		 * USB device was yanked out.  Or it could happen to
4310 		 * be a transient write error and maybe the block will
4311 		 * be remapped.  Nothing we can do but to retry the
4312 		 * write and hope for the best.
4313 		 */
4314 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4315 		       "superblock detected");
4316 		clear_buffer_write_io_error(sbh);
4317 		set_buffer_uptodate(sbh);
4318 	}
4319 	/*
4320 	 * If the file system is mounted read-only, don't update the
4321 	 * superblock write time.  This avoids updating the superblock
4322 	 * write time when we are mounting the root file system
4323 	 * read/only but we need to replay the journal; at that point,
4324 	 * for people who are east of GMT and who make their clock
4325 	 * tick in localtime for Windows bug-for-bug compatibility,
4326 	 * the clock is set in the future, and this will cause e2fsck
4327 	 * to complain and force a full file system check.
4328 	 */
4329 	if (!(sb->s_flags & MS_RDONLY))
4330 		es->s_wtime = cpu_to_le32(get_seconds());
4331 	if (sb->s_bdev->bd_part)
4332 		es->s_kbytes_written =
4333 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4334 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4335 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4336 	else
4337 		es->s_kbytes_written =
4338 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4339 	ext4_free_blocks_count_set(es,
4340 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4341 				&EXT4_SB(sb)->s_freeclusters_counter)));
4342 	es->s_free_inodes_count =
4343 		cpu_to_le32(percpu_counter_sum_positive(
4344 				&EXT4_SB(sb)->s_freeinodes_counter));
4345 	BUFFER_TRACE(sbh, "marking dirty");
4346 	ext4_superblock_csum_set(sb, es);
4347 	mark_buffer_dirty(sbh);
4348 	if (sync) {
4349 		error = sync_dirty_buffer(sbh);
4350 		if (error)
4351 			return error;
4352 
4353 		error = buffer_write_io_error(sbh);
4354 		if (error) {
4355 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4356 			       "superblock");
4357 			clear_buffer_write_io_error(sbh);
4358 			set_buffer_uptodate(sbh);
4359 		}
4360 	}
4361 	return error;
4362 }
4363 
4364 /*
4365  * Have we just finished recovery?  If so, and if we are mounting (or
4366  * remounting) the filesystem readonly, then we will end up with a
4367  * consistent fs on disk.  Record that fact.
4368  */
4369 static void ext4_mark_recovery_complete(struct super_block *sb,
4370 					struct ext4_super_block *es)
4371 {
4372 	journal_t *journal = EXT4_SB(sb)->s_journal;
4373 
4374 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4375 		BUG_ON(journal != NULL);
4376 		return;
4377 	}
4378 	jbd2_journal_lock_updates(journal);
4379 	if (jbd2_journal_flush(journal) < 0)
4380 		goto out;
4381 
4382 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4383 	    sb->s_flags & MS_RDONLY) {
4384 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4385 		ext4_commit_super(sb, 1);
4386 	}
4387 
4388 out:
4389 	jbd2_journal_unlock_updates(journal);
4390 }
4391 
4392 /*
4393  * If we are mounting (or read-write remounting) a filesystem whose journal
4394  * has recorded an error from a previous lifetime, move that error to the
4395  * main filesystem now.
4396  */
4397 static void ext4_clear_journal_err(struct super_block *sb,
4398 				   struct ext4_super_block *es)
4399 {
4400 	journal_t *journal;
4401 	int j_errno;
4402 	const char *errstr;
4403 
4404 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4405 
4406 	journal = EXT4_SB(sb)->s_journal;
4407 
4408 	/*
4409 	 * Now check for any error status which may have been recorded in the
4410 	 * journal by a prior ext4_error() or ext4_abort()
4411 	 */
4412 
4413 	j_errno = jbd2_journal_errno(journal);
4414 	if (j_errno) {
4415 		char nbuf[16];
4416 
4417 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4418 		ext4_warning(sb, "Filesystem error recorded "
4419 			     "from previous mount: %s", errstr);
4420 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4421 
4422 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4423 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4424 		ext4_commit_super(sb, 1);
4425 
4426 		jbd2_journal_clear_err(journal);
4427 		jbd2_journal_update_sb_errno(journal);
4428 	}
4429 }
4430 
4431 /*
4432  * Force the running and committing transactions to commit,
4433  * and wait on the commit.
4434  */
4435 int ext4_force_commit(struct super_block *sb)
4436 {
4437 	journal_t *journal;
4438 	int ret = 0;
4439 
4440 	if (sb->s_flags & MS_RDONLY)
4441 		return 0;
4442 
4443 	journal = EXT4_SB(sb)->s_journal;
4444 	if (journal)
4445 		ret = ext4_journal_force_commit(journal);
4446 
4447 	return ret;
4448 }
4449 
4450 static int ext4_sync_fs(struct super_block *sb, int wait)
4451 {
4452 	int ret = 0;
4453 	tid_t target;
4454 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4455 
4456 	trace_ext4_sync_fs(sb, wait);
4457 	flush_workqueue(sbi->dio_unwritten_wq);
4458 	/*
4459 	 * Writeback quota in non-journalled quota case - journalled quota has
4460 	 * no dirty dquots
4461 	 */
4462 	dquot_writeback_dquots(sb, -1);
4463 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4464 		if (wait)
4465 			jbd2_log_wait_commit(sbi->s_journal, target);
4466 	}
4467 	return ret;
4468 }
4469 
4470 /*
4471  * LVM calls this function before a (read-only) snapshot is created.  This
4472  * gives us a chance to flush the journal completely and mark the fs clean.
4473  *
4474  * Note that only this function cannot bring a filesystem to be in a clean
4475  * state independently. It relies on upper layer to stop all data & metadata
4476  * modifications.
4477  */
4478 static int ext4_freeze(struct super_block *sb)
4479 {
4480 	int error = 0;
4481 	journal_t *journal;
4482 
4483 	if (sb->s_flags & MS_RDONLY)
4484 		return 0;
4485 
4486 	journal = EXT4_SB(sb)->s_journal;
4487 
4488 	/* Now we set up the journal barrier. */
4489 	jbd2_journal_lock_updates(journal);
4490 
4491 	/*
4492 	 * Don't clear the needs_recovery flag if we failed to flush
4493 	 * the journal.
4494 	 */
4495 	error = jbd2_journal_flush(journal);
4496 	if (error < 0)
4497 		goto out;
4498 
4499 	/* Journal blocked and flushed, clear needs_recovery flag. */
4500 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4501 	error = ext4_commit_super(sb, 1);
4502 out:
4503 	/* we rely on upper layer to stop further updates */
4504 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4505 	return error;
4506 }
4507 
4508 /*
4509  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4510  * flag here, even though the filesystem is not technically dirty yet.
4511  */
4512 static int ext4_unfreeze(struct super_block *sb)
4513 {
4514 	if (sb->s_flags & MS_RDONLY)
4515 		return 0;
4516 
4517 	lock_super(sb);
4518 	/* Reset the needs_recovery flag before the fs is unlocked. */
4519 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4520 	ext4_commit_super(sb, 1);
4521 	unlock_super(sb);
4522 	return 0;
4523 }
4524 
4525 /*
4526  * Structure to save mount options for ext4_remount's benefit
4527  */
4528 struct ext4_mount_options {
4529 	unsigned long s_mount_opt;
4530 	unsigned long s_mount_opt2;
4531 	kuid_t s_resuid;
4532 	kgid_t s_resgid;
4533 	unsigned long s_commit_interval;
4534 	u32 s_min_batch_time, s_max_batch_time;
4535 #ifdef CONFIG_QUOTA
4536 	int s_jquota_fmt;
4537 	char *s_qf_names[MAXQUOTAS];
4538 #endif
4539 };
4540 
4541 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4542 {
4543 	struct ext4_super_block *es;
4544 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4545 	unsigned long old_sb_flags;
4546 	struct ext4_mount_options old_opts;
4547 	int enable_quota = 0;
4548 	ext4_group_t g;
4549 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4550 	int err = 0;
4551 #ifdef CONFIG_QUOTA
4552 	int i;
4553 #endif
4554 	char *orig_data = kstrdup(data, GFP_KERNEL);
4555 
4556 	/* Store the original options */
4557 	lock_super(sb);
4558 	old_sb_flags = sb->s_flags;
4559 	old_opts.s_mount_opt = sbi->s_mount_opt;
4560 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4561 	old_opts.s_resuid = sbi->s_resuid;
4562 	old_opts.s_resgid = sbi->s_resgid;
4563 	old_opts.s_commit_interval = sbi->s_commit_interval;
4564 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4565 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4566 #ifdef CONFIG_QUOTA
4567 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4568 	for (i = 0; i < MAXQUOTAS; i++)
4569 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4570 #endif
4571 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4572 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4573 
4574 	/*
4575 	 * Allow the "check" option to be passed as a remount option.
4576 	 */
4577 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4578 		err = -EINVAL;
4579 		goto restore_opts;
4580 	}
4581 
4582 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4583 		ext4_abort(sb, "Abort forced by user");
4584 
4585 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4586 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4587 
4588 	es = sbi->s_es;
4589 
4590 	if (sbi->s_journal) {
4591 		ext4_init_journal_params(sb, sbi->s_journal);
4592 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4593 	}
4594 
4595 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4596 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4597 			err = -EROFS;
4598 			goto restore_opts;
4599 		}
4600 
4601 		if (*flags & MS_RDONLY) {
4602 			err = dquot_suspend(sb, -1);
4603 			if (err < 0)
4604 				goto restore_opts;
4605 
4606 			/*
4607 			 * First of all, the unconditional stuff we have to do
4608 			 * to disable replay of the journal when we next remount
4609 			 */
4610 			sb->s_flags |= MS_RDONLY;
4611 
4612 			/*
4613 			 * OK, test if we are remounting a valid rw partition
4614 			 * readonly, and if so set the rdonly flag and then
4615 			 * mark the partition as valid again.
4616 			 */
4617 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4618 			    (sbi->s_mount_state & EXT4_VALID_FS))
4619 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4620 
4621 			if (sbi->s_journal)
4622 				ext4_mark_recovery_complete(sb, es);
4623 		} else {
4624 			/* Make sure we can mount this feature set readwrite */
4625 			if (!ext4_feature_set_ok(sb, 0)) {
4626 				err = -EROFS;
4627 				goto restore_opts;
4628 			}
4629 			/*
4630 			 * Make sure the group descriptor checksums
4631 			 * are sane.  If they aren't, refuse to remount r/w.
4632 			 */
4633 			for (g = 0; g < sbi->s_groups_count; g++) {
4634 				struct ext4_group_desc *gdp =
4635 					ext4_get_group_desc(sb, g, NULL);
4636 
4637 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4638 					ext4_msg(sb, KERN_ERR,
4639 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4640 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4641 					       le16_to_cpu(gdp->bg_checksum));
4642 					err = -EINVAL;
4643 					goto restore_opts;
4644 				}
4645 			}
4646 
4647 			/*
4648 			 * If we have an unprocessed orphan list hanging
4649 			 * around from a previously readonly bdev mount,
4650 			 * require a full umount/remount for now.
4651 			 */
4652 			if (es->s_last_orphan) {
4653 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4654 				       "remount RDWR because of unprocessed "
4655 				       "orphan inode list.  Please "
4656 				       "umount/remount instead");
4657 				err = -EINVAL;
4658 				goto restore_opts;
4659 			}
4660 
4661 			/*
4662 			 * Mounting a RDONLY partition read-write, so reread
4663 			 * and store the current valid flag.  (It may have
4664 			 * been changed by e2fsck since we originally mounted
4665 			 * the partition.)
4666 			 */
4667 			if (sbi->s_journal)
4668 				ext4_clear_journal_err(sb, es);
4669 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4670 			if (!ext4_setup_super(sb, es, 0))
4671 				sb->s_flags &= ~MS_RDONLY;
4672 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4673 						     EXT4_FEATURE_INCOMPAT_MMP))
4674 				if (ext4_multi_mount_protect(sb,
4675 						le64_to_cpu(es->s_mmp_block))) {
4676 					err = -EROFS;
4677 					goto restore_opts;
4678 				}
4679 			enable_quota = 1;
4680 		}
4681 	}
4682 
4683 	/*
4684 	 * Reinitialize lazy itable initialization thread based on
4685 	 * current settings
4686 	 */
4687 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4688 		ext4_unregister_li_request(sb);
4689 	else {
4690 		ext4_group_t first_not_zeroed;
4691 		first_not_zeroed = ext4_has_uninit_itable(sb);
4692 		ext4_register_li_request(sb, first_not_zeroed);
4693 	}
4694 
4695 	ext4_setup_system_zone(sb);
4696 	if (sbi->s_journal == NULL)
4697 		ext4_commit_super(sb, 1);
4698 
4699 	unlock_super(sb);
4700 #ifdef CONFIG_QUOTA
4701 	/* Release old quota file names */
4702 	for (i = 0; i < MAXQUOTAS; i++)
4703 		if (old_opts.s_qf_names[i] &&
4704 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4705 			kfree(old_opts.s_qf_names[i]);
4706 	if (enable_quota) {
4707 		if (sb_any_quota_suspended(sb))
4708 			dquot_resume(sb, -1);
4709 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4710 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4711 			err = ext4_enable_quotas(sb);
4712 			if (err) {
4713 				lock_super(sb);
4714 				goto restore_opts;
4715 			}
4716 		}
4717 	}
4718 #endif
4719 
4720 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4721 	kfree(orig_data);
4722 	return 0;
4723 
4724 restore_opts:
4725 	sb->s_flags = old_sb_flags;
4726 	sbi->s_mount_opt = old_opts.s_mount_opt;
4727 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4728 	sbi->s_resuid = old_opts.s_resuid;
4729 	sbi->s_resgid = old_opts.s_resgid;
4730 	sbi->s_commit_interval = old_opts.s_commit_interval;
4731 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4732 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4733 #ifdef CONFIG_QUOTA
4734 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4735 	for (i = 0; i < MAXQUOTAS; i++) {
4736 		if (sbi->s_qf_names[i] &&
4737 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4738 			kfree(sbi->s_qf_names[i]);
4739 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4740 	}
4741 #endif
4742 	unlock_super(sb);
4743 	kfree(orig_data);
4744 	return err;
4745 }
4746 
4747 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4748 {
4749 	struct super_block *sb = dentry->d_sb;
4750 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4751 	struct ext4_super_block *es = sbi->s_es;
4752 	ext4_fsblk_t overhead = 0;
4753 	u64 fsid;
4754 	s64 bfree;
4755 
4756 	if (!test_opt(sb, MINIX_DF))
4757 		overhead = sbi->s_overhead;
4758 
4759 	buf->f_type = EXT4_SUPER_MAGIC;
4760 	buf->f_bsize = sb->s_blocksize;
4761 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
4762 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4763 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4764 	/* prevent underflow in case that few free space is available */
4765 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4766 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4767 	if (buf->f_bfree < ext4_r_blocks_count(es))
4768 		buf->f_bavail = 0;
4769 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4770 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4771 	buf->f_namelen = EXT4_NAME_LEN;
4772 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4773 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4774 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4775 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4776 
4777 	return 0;
4778 }
4779 
4780 /* Helper function for writing quotas on sync - we need to start transaction
4781  * before quota file is locked for write. Otherwise the are possible deadlocks:
4782  * Process 1                         Process 2
4783  * ext4_create()                     quota_sync()
4784  *   jbd2_journal_start()                  write_dquot()
4785  *   dquot_initialize()                         down(dqio_mutex)
4786  *     down(dqio_mutex)                    jbd2_journal_start()
4787  *
4788  */
4789 
4790 #ifdef CONFIG_QUOTA
4791 
4792 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4793 {
4794 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4795 }
4796 
4797 static int ext4_write_dquot(struct dquot *dquot)
4798 {
4799 	int ret, err;
4800 	handle_t *handle;
4801 	struct inode *inode;
4802 
4803 	inode = dquot_to_inode(dquot);
4804 	handle = ext4_journal_start(inode,
4805 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4806 	if (IS_ERR(handle))
4807 		return PTR_ERR(handle);
4808 	ret = dquot_commit(dquot);
4809 	err = ext4_journal_stop(handle);
4810 	if (!ret)
4811 		ret = err;
4812 	return ret;
4813 }
4814 
4815 static int ext4_acquire_dquot(struct dquot *dquot)
4816 {
4817 	int ret, err;
4818 	handle_t *handle;
4819 
4820 	handle = ext4_journal_start(dquot_to_inode(dquot),
4821 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4822 	if (IS_ERR(handle))
4823 		return PTR_ERR(handle);
4824 	ret = dquot_acquire(dquot);
4825 	err = ext4_journal_stop(handle);
4826 	if (!ret)
4827 		ret = err;
4828 	return ret;
4829 }
4830 
4831 static int ext4_release_dquot(struct dquot *dquot)
4832 {
4833 	int ret, err;
4834 	handle_t *handle;
4835 
4836 	handle = ext4_journal_start(dquot_to_inode(dquot),
4837 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4838 	if (IS_ERR(handle)) {
4839 		/* Release dquot anyway to avoid endless cycle in dqput() */
4840 		dquot_release(dquot);
4841 		return PTR_ERR(handle);
4842 	}
4843 	ret = dquot_release(dquot);
4844 	err = ext4_journal_stop(handle);
4845 	if (!ret)
4846 		ret = err;
4847 	return ret;
4848 }
4849 
4850 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4851 {
4852 	/* Are we journaling quotas? */
4853 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4854 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4855 		dquot_mark_dquot_dirty(dquot);
4856 		return ext4_write_dquot(dquot);
4857 	} else {
4858 		return dquot_mark_dquot_dirty(dquot);
4859 	}
4860 }
4861 
4862 static int ext4_write_info(struct super_block *sb, int type)
4863 {
4864 	int ret, err;
4865 	handle_t *handle;
4866 
4867 	/* Data block + inode block */
4868 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
4869 	if (IS_ERR(handle))
4870 		return PTR_ERR(handle);
4871 	ret = dquot_commit_info(sb, type);
4872 	err = ext4_journal_stop(handle);
4873 	if (!ret)
4874 		ret = err;
4875 	return ret;
4876 }
4877 
4878 /*
4879  * Turn on quotas during mount time - we need to find
4880  * the quota file and such...
4881  */
4882 static int ext4_quota_on_mount(struct super_block *sb, int type)
4883 {
4884 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4885 					EXT4_SB(sb)->s_jquota_fmt, type);
4886 }
4887 
4888 /*
4889  * Standard function to be called on quota_on
4890  */
4891 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4892 			 struct path *path)
4893 {
4894 	int err;
4895 
4896 	if (!test_opt(sb, QUOTA))
4897 		return -EINVAL;
4898 
4899 	/* Quotafile not on the same filesystem? */
4900 	if (path->dentry->d_sb != sb)
4901 		return -EXDEV;
4902 	/* Journaling quota? */
4903 	if (EXT4_SB(sb)->s_qf_names[type]) {
4904 		/* Quotafile not in fs root? */
4905 		if (path->dentry->d_parent != sb->s_root)
4906 			ext4_msg(sb, KERN_WARNING,
4907 				"Quota file not on filesystem root. "
4908 				"Journaled quota will not work");
4909 	}
4910 
4911 	/*
4912 	 * When we journal data on quota file, we have to flush journal to see
4913 	 * all updates to the file when we bypass pagecache...
4914 	 */
4915 	if (EXT4_SB(sb)->s_journal &&
4916 	    ext4_should_journal_data(path->dentry->d_inode)) {
4917 		/*
4918 		 * We don't need to lock updates but journal_flush() could
4919 		 * otherwise be livelocked...
4920 		 */
4921 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4922 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4923 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4924 		if (err)
4925 			return err;
4926 	}
4927 
4928 	return dquot_quota_on(sb, type, format_id, path);
4929 }
4930 
4931 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4932 			     unsigned int flags)
4933 {
4934 	int err;
4935 	struct inode *qf_inode;
4936 	unsigned long qf_inums[MAXQUOTAS] = {
4937 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4938 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4939 	};
4940 
4941 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4942 
4943 	if (!qf_inums[type])
4944 		return -EPERM;
4945 
4946 	qf_inode = ext4_iget(sb, qf_inums[type]);
4947 	if (IS_ERR(qf_inode)) {
4948 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4949 		return PTR_ERR(qf_inode);
4950 	}
4951 
4952 	err = dquot_enable(qf_inode, type, format_id, flags);
4953 	iput(qf_inode);
4954 
4955 	return err;
4956 }
4957 
4958 /* Enable usage tracking for all quota types. */
4959 static int ext4_enable_quotas(struct super_block *sb)
4960 {
4961 	int type, err = 0;
4962 	unsigned long qf_inums[MAXQUOTAS] = {
4963 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4964 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4965 	};
4966 
4967 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
4968 	for (type = 0; type < MAXQUOTAS; type++) {
4969 		if (qf_inums[type]) {
4970 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
4971 						DQUOT_USAGE_ENABLED);
4972 			if (err) {
4973 				ext4_warning(sb,
4974 					"Failed to enable quota (type=%d) "
4975 					"tracking. Please run e2fsck to fix.",
4976 					type);
4977 				return err;
4978 			}
4979 		}
4980 	}
4981 	return 0;
4982 }
4983 
4984 /*
4985  * quota_on function that is used when QUOTA feature is set.
4986  */
4987 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
4988 				 int format_id)
4989 {
4990 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4991 		return -EINVAL;
4992 
4993 	/*
4994 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
4995 	 */
4996 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
4997 }
4998 
4999 static int ext4_quota_off(struct super_block *sb, int type)
5000 {
5001 	struct inode *inode = sb_dqopt(sb)->files[type];
5002 	handle_t *handle;
5003 
5004 	/* Force all delayed allocation blocks to be allocated.
5005 	 * Caller already holds s_umount sem */
5006 	if (test_opt(sb, DELALLOC))
5007 		sync_filesystem(sb);
5008 
5009 	if (!inode)
5010 		goto out;
5011 
5012 	/* Update modification times of quota files when userspace can
5013 	 * start looking at them */
5014 	handle = ext4_journal_start(inode, 1);
5015 	if (IS_ERR(handle))
5016 		goto out;
5017 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5018 	ext4_mark_inode_dirty(handle, inode);
5019 	ext4_journal_stop(handle);
5020 
5021 out:
5022 	return dquot_quota_off(sb, type);
5023 }
5024 
5025 /*
5026  * quota_off function that is used when QUOTA feature is set.
5027  */
5028 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5029 {
5030 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5031 		return -EINVAL;
5032 
5033 	/* Disable only the limits. */
5034 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5035 }
5036 
5037 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5038  * acquiring the locks... As quota files are never truncated and quota code
5039  * itself serializes the operations (and no one else should touch the files)
5040  * we don't have to be afraid of races */
5041 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5042 			       size_t len, loff_t off)
5043 {
5044 	struct inode *inode = sb_dqopt(sb)->files[type];
5045 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5046 	int err = 0;
5047 	int offset = off & (sb->s_blocksize - 1);
5048 	int tocopy;
5049 	size_t toread;
5050 	struct buffer_head *bh;
5051 	loff_t i_size = i_size_read(inode);
5052 
5053 	if (off > i_size)
5054 		return 0;
5055 	if (off+len > i_size)
5056 		len = i_size-off;
5057 	toread = len;
5058 	while (toread > 0) {
5059 		tocopy = sb->s_blocksize - offset < toread ?
5060 				sb->s_blocksize - offset : toread;
5061 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5062 		if (err)
5063 			return err;
5064 		if (!bh)	/* A hole? */
5065 			memset(data, 0, tocopy);
5066 		else
5067 			memcpy(data, bh->b_data+offset, tocopy);
5068 		brelse(bh);
5069 		offset = 0;
5070 		toread -= tocopy;
5071 		data += tocopy;
5072 		blk++;
5073 	}
5074 	return len;
5075 }
5076 
5077 /* Write to quotafile (we know the transaction is already started and has
5078  * enough credits) */
5079 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5080 				const char *data, size_t len, loff_t off)
5081 {
5082 	struct inode *inode = sb_dqopt(sb)->files[type];
5083 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5084 	int err = 0;
5085 	int offset = off & (sb->s_blocksize - 1);
5086 	struct buffer_head *bh;
5087 	handle_t *handle = journal_current_handle();
5088 
5089 	if (EXT4_SB(sb)->s_journal && !handle) {
5090 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5091 			" cancelled because transaction is not started",
5092 			(unsigned long long)off, (unsigned long long)len);
5093 		return -EIO;
5094 	}
5095 	/*
5096 	 * Since we account only one data block in transaction credits,
5097 	 * then it is impossible to cross a block boundary.
5098 	 */
5099 	if (sb->s_blocksize - offset < len) {
5100 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5101 			" cancelled because not block aligned",
5102 			(unsigned long long)off, (unsigned long long)len);
5103 		return -EIO;
5104 	}
5105 
5106 	bh = ext4_bread(handle, inode, blk, 1, &err);
5107 	if (!bh)
5108 		goto out;
5109 	err = ext4_journal_get_write_access(handle, bh);
5110 	if (err) {
5111 		brelse(bh);
5112 		goto out;
5113 	}
5114 	lock_buffer(bh);
5115 	memcpy(bh->b_data+offset, data, len);
5116 	flush_dcache_page(bh->b_page);
5117 	unlock_buffer(bh);
5118 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5119 	brelse(bh);
5120 out:
5121 	if (err)
5122 		return err;
5123 	if (inode->i_size < off + len) {
5124 		i_size_write(inode, off + len);
5125 		EXT4_I(inode)->i_disksize = inode->i_size;
5126 		ext4_mark_inode_dirty(handle, inode);
5127 	}
5128 	return len;
5129 }
5130 
5131 #endif
5132 
5133 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5134 		       const char *dev_name, void *data)
5135 {
5136 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5137 }
5138 
5139 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5140 static inline void register_as_ext2(void)
5141 {
5142 	int err = register_filesystem(&ext2_fs_type);
5143 	if (err)
5144 		printk(KERN_WARNING
5145 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5146 }
5147 
5148 static inline void unregister_as_ext2(void)
5149 {
5150 	unregister_filesystem(&ext2_fs_type);
5151 }
5152 
5153 static inline int ext2_feature_set_ok(struct super_block *sb)
5154 {
5155 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5156 		return 0;
5157 	if (sb->s_flags & MS_RDONLY)
5158 		return 1;
5159 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5160 		return 0;
5161 	return 1;
5162 }
5163 MODULE_ALIAS("ext2");
5164 #else
5165 static inline void register_as_ext2(void) { }
5166 static inline void unregister_as_ext2(void) { }
5167 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5168 #endif
5169 
5170 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5171 static inline void register_as_ext3(void)
5172 {
5173 	int err = register_filesystem(&ext3_fs_type);
5174 	if (err)
5175 		printk(KERN_WARNING
5176 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5177 }
5178 
5179 static inline void unregister_as_ext3(void)
5180 {
5181 	unregister_filesystem(&ext3_fs_type);
5182 }
5183 
5184 static inline int ext3_feature_set_ok(struct super_block *sb)
5185 {
5186 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5187 		return 0;
5188 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5189 		return 0;
5190 	if (sb->s_flags & MS_RDONLY)
5191 		return 1;
5192 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5193 		return 0;
5194 	return 1;
5195 }
5196 MODULE_ALIAS("ext3");
5197 #else
5198 static inline void register_as_ext3(void) { }
5199 static inline void unregister_as_ext3(void) { }
5200 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5201 #endif
5202 
5203 static struct file_system_type ext4_fs_type = {
5204 	.owner		= THIS_MODULE,
5205 	.name		= "ext4",
5206 	.mount		= ext4_mount,
5207 	.kill_sb	= kill_block_super,
5208 	.fs_flags	= FS_REQUIRES_DEV,
5209 };
5210 
5211 static int __init ext4_init_feat_adverts(void)
5212 {
5213 	struct ext4_features *ef;
5214 	int ret = -ENOMEM;
5215 
5216 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5217 	if (!ef)
5218 		goto out;
5219 
5220 	ef->f_kobj.kset = ext4_kset;
5221 	init_completion(&ef->f_kobj_unregister);
5222 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5223 				   "features");
5224 	if (ret) {
5225 		kfree(ef);
5226 		goto out;
5227 	}
5228 
5229 	ext4_feat = ef;
5230 	ret = 0;
5231 out:
5232 	return ret;
5233 }
5234 
5235 static void ext4_exit_feat_adverts(void)
5236 {
5237 	kobject_put(&ext4_feat->f_kobj);
5238 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5239 	kfree(ext4_feat);
5240 }
5241 
5242 /* Shared across all ext4 file systems */
5243 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5244 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5245 
5246 static int __init ext4_init_fs(void)
5247 {
5248 	int i, err;
5249 
5250 	ext4_li_info = NULL;
5251 	mutex_init(&ext4_li_mtx);
5252 
5253 	ext4_check_flag_values();
5254 
5255 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5256 		mutex_init(&ext4__aio_mutex[i]);
5257 		init_waitqueue_head(&ext4__ioend_wq[i]);
5258 	}
5259 
5260 	err = ext4_init_pageio();
5261 	if (err)
5262 		return err;
5263 	err = ext4_init_system_zone();
5264 	if (err)
5265 		goto out6;
5266 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5267 	if (!ext4_kset)
5268 		goto out5;
5269 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5270 
5271 	err = ext4_init_feat_adverts();
5272 	if (err)
5273 		goto out4;
5274 
5275 	err = ext4_init_mballoc();
5276 	if (err)
5277 		goto out3;
5278 
5279 	err = ext4_init_xattr();
5280 	if (err)
5281 		goto out2;
5282 	err = init_inodecache();
5283 	if (err)
5284 		goto out1;
5285 	register_as_ext3();
5286 	register_as_ext2();
5287 	err = register_filesystem(&ext4_fs_type);
5288 	if (err)
5289 		goto out;
5290 
5291 	return 0;
5292 out:
5293 	unregister_as_ext2();
5294 	unregister_as_ext3();
5295 	destroy_inodecache();
5296 out1:
5297 	ext4_exit_xattr();
5298 out2:
5299 	ext4_exit_mballoc();
5300 out3:
5301 	ext4_exit_feat_adverts();
5302 out4:
5303 	if (ext4_proc_root)
5304 		remove_proc_entry("fs/ext4", NULL);
5305 	kset_unregister(ext4_kset);
5306 out5:
5307 	ext4_exit_system_zone();
5308 out6:
5309 	ext4_exit_pageio();
5310 	return err;
5311 }
5312 
5313 static void __exit ext4_exit_fs(void)
5314 {
5315 	ext4_destroy_lazyinit_thread();
5316 	unregister_as_ext2();
5317 	unregister_as_ext3();
5318 	unregister_filesystem(&ext4_fs_type);
5319 	destroy_inodecache();
5320 	ext4_exit_xattr();
5321 	ext4_exit_mballoc();
5322 	ext4_exit_feat_adverts();
5323 	remove_proc_entry("fs/ext4", NULL);
5324 	kset_unregister(ext4_kset);
5325 	ext4_exit_system_zone();
5326 	ext4_exit_pageio();
5327 }
5328 
5329 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5330 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5331 MODULE_LICENSE("GPL");
5332 module_init(ext4_init_fs)
5333 module_exit(ext4_exit_fs)
5334