xref: /linux/fs/ext4/super.c (revision c116cc94969447f44fd7205a027084ceebe90d34)
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  * The only special thing we need to do here is to make sure that all
331  * journal_end calls result in the superblock being marked dirty, so
332  * that sync() will call the filesystem's write_super callback if
333  * appropriate.
334  */
335 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
336 {
337 	journal_t *journal;
338 
339 	trace_ext4_journal_start(sb, nblocks, _RET_IP_);
340 	if (sb->s_flags & MS_RDONLY)
341 		return ERR_PTR(-EROFS);
342 
343 	WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
344 	journal = EXT4_SB(sb)->s_journal;
345 	if (!journal)
346 		return ext4_get_nojournal();
347 	/*
348 	 * Special case here: if the journal has aborted behind our
349 	 * backs (eg. EIO in the commit thread), then we still need to
350 	 * take the FS itself readonly cleanly.
351 	 */
352 	if (is_journal_aborted(journal)) {
353 		ext4_abort(sb, "Detected aborted journal");
354 		return ERR_PTR(-EROFS);
355 	}
356 	return jbd2_journal_start(journal, nblocks);
357 }
358 
359 /*
360  * The only special thing we need to do here is to make sure that all
361  * jbd2_journal_stop calls result in the superblock being marked dirty, so
362  * that sync() will call the filesystem's write_super callback if
363  * appropriate.
364  */
365 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
366 {
367 	struct super_block *sb;
368 	int err;
369 	int rc;
370 
371 	if (!ext4_handle_valid(handle)) {
372 		ext4_put_nojournal(handle);
373 		return 0;
374 	}
375 	sb = handle->h_transaction->t_journal->j_private;
376 	err = handle->h_err;
377 	rc = jbd2_journal_stop(handle);
378 
379 	if (!err)
380 		err = rc;
381 	if (err)
382 		__ext4_std_error(sb, where, line, err);
383 	return err;
384 }
385 
386 void ext4_journal_abort_handle(const char *caller, unsigned int line,
387 			       const char *err_fn, struct buffer_head *bh,
388 			       handle_t *handle, int err)
389 {
390 	char nbuf[16];
391 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
392 
393 	BUG_ON(!ext4_handle_valid(handle));
394 
395 	if (bh)
396 		BUFFER_TRACE(bh, "abort");
397 
398 	if (!handle->h_err)
399 		handle->h_err = err;
400 
401 	if (is_handle_aborted(handle))
402 		return;
403 
404 	printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
405 	       caller, line, errstr, err_fn);
406 
407 	jbd2_journal_abort_handle(handle);
408 }
409 
410 static void __save_error_info(struct super_block *sb, const char *func,
411 			    unsigned int line)
412 {
413 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
414 
415 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
416 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
417 	es->s_last_error_time = cpu_to_le32(get_seconds());
418 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
419 	es->s_last_error_line = cpu_to_le32(line);
420 	if (!es->s_first_error_time) {
421 		es->s_first_error_time = es->s_last_error_time;
422 		strncpy(es->s_first_error_func, func,
423 			sizeof(es->s_first_error_func));
424 		es->s_first_error_line = cpu_to_le32(line);
425 		es->s_first_error_ino = es->s_last_error_ino;
426 		es->s_first_error_block = es->s_last_error_block;
427 	}
428 	/*
429 	 * Start the daily error reporting function if it hasn't been
430 	 * started already
431 	 */
432 	if (!es->s_error_count)
433 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
434 	es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
435 }
436 
437 static void save_error_info(struct super_block *sb, const char *func,
438 			    unsigned int line)
439 {
440 	__save_error_info(sb, func, line);
441 	ext4_commit_super(sb, 1);
442 }
443 
444 /*
445  * The del_gendisk() function uninitializes the disk-specific data
446  * structures, including the bdi structure, without telling anyone
447  * else.  Once this happens, any attempt to call mark_buffer_dirty()
448  * (for example, by ext4_commit_super), will cause a kernel OOPS.
449  * This is a kludge to prevent these oops until we can put in a proper
450  * hook in del_gendisk() to inform the VFS and file system layers.
451  */
452 static int block_device_ejected(struct super_block *sb)
453 {
454 	struct inode *bd_inode = sb->s_bdev->bd_inode;
455 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
456 
457 	return bdi->dev == NULL;
458 }
459 
460 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
461 {
462 	struct super_block		*sb = journal->j_private;
463 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
464 	int				error = is_journal_aborted(journal);
465 	struct ext4_journal_cb_entry	*jce, *tmp;
466 
467 	spin_lock(&sbi->s_md_lock);
468 	list_for_each_entry_safe(jce, tmp, &txn->t_private_list, jce_list) {
469 		list_del_init(&jce->jce_list);
470 		spin_unlock(&sbi->s_md_lock);
471 		jce->jce_func(sb, jce, error);
472 		spin_lock(&sbi->s_md_lock);
473 	}
474 	spin_unlock(&sbi->s_md_lock);
475 }
476 
477 /* Deal with the reporting of failure conditions on a filesystem such as
478  * inconsistencies detected or read IO failures.
479  *
480  * On ext2, we can store the error state of the filesystem in the
481  * superblock.  That is not possible on ext4, because we may have other
482  * write ordering constraints on the superblock which prevent us from
483  * writing it out straight away; and given that the journal is about to
484  * be aborted, we can't rely on the current, or future, transactions to
485  * write out the superblock safely.
486  *
487  * We'll just use the jbd2_journal_abort() error code to record an error in
488  * the journal instead.  On recovery, the journal will complain about
489  * that error until we've noted it down and cleared it.
490  */
491 
492 static void ext4_handle_error(struct super_block *sb)
493 {
494 	if (sb->s_flags & MS_RDONLY)
495 		return;
496 
497 	if (!test_opt(sb, ERRORS_CONT)) {
498 		journal_t *journal = EXT4_SB(sb)->s_journal;
499 
500 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
501 		if (journal)
502 			jbd2_journal_abort(journal, -EIO);
503 	}
504 	if (test_opt(sb, ERRORS_RO)) {
505 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
506 		sb->s_flags |= MS_RDONLY;
507 	}
508 	if (test_opt(sb, ERRORS_PANIC))
509 		panic("EXT4-fs (device %s): panic forced after error\n",
510 			sb->s_id);
511 }
512 
513 void __ext4_error(struct super_block *sb, const char *function,
514 		  unsigned int line, const char *fmt, ...)
515 {
516 	struct va_format vaf;
517 	va_list args;
518 
519 	va_start(args, fmt);
520 	vaf.fmt = fmt;
521 	vaf.va = &args;
522 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
523 	       sb->s_id, function, line, current->comm, &vaf);
524 	va_end(args);
525 	save_error_info(sb, function, line);
526 
527 	ext4_handle_error(sb);
528 }
529 
530 void ext4_error_inode(struct inode *inode, const char *function,
531 		      unsigned int line, ext4_fsblk_t block,
532 		      const char *fmt, ...)
533 {
534 	va_list args;
535 	struct va_format vaf;
536 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
537 
538 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
539 	es->s_last_error_block = cpu_to_le64(block);
540 	save_error_info(inode->i_sb, function, line);
541 	va_start(args, fmt);
542 	vaf.fmt = fmt;
543 	vaf.va = &args;
544 	if (block)
545 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
546 		       "inode #%lu: block %llu: comm %s: %pV\n",
547 		       inode->i_sb->s_id, function, line, inode->i_ino,
548 		       block, current->comm, &vaf);
549 	else
550 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
551 		       "inode #%lu: comm %s: %pV\n",
552 		       inode->i_sb->s_id, function, line, inode->i_ino,
553 		       current->comm, &vaf);
554 	va_end(args);
555 
556 	ext4_handle_error(inode->i_sb);
557 }
558 
559 void ext4_error_file(struct file *file, const char *function,
560 		     unsigned int line, ext4_fsblk_t block,
561 		     const char *fmt, ...)
562 {
563 	va_list args;
564 	struct va_format vaf;
565 	struct ext4_super_block *es;
566 	struct inode *inode = file->f_dentry->d_inode;
567 	char pathname[80], *path;
568 
569 	es = EXT4_SB(inode->i_sb)->s_es;
570 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
571 	save_error_info(inode->i_sb, function, line);
572 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
573 	if (IS_ERR(path))
574 		path = "(unknown)";
575 	va_start(args, fmt);
576 	vaf.fmt = fmt;
577 	vaf.va = &args;
578 	if (block)
579 		printk(KERN_CRIT
580 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
581 		       "block %llu: comm %s: path %s: %pV\n",
582 		       inode->i_sb->s_id, function, line, inode->i_ino,
583 		       block, current->comm, path, &vaf);
584 	else
585 		printk(KERN_CRIT
586 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
587 		       "comm %s: path %s: %pV\n",
588 		       inode->i_sb->s_id, function, line, inode->i_ino,
589 		       current->comm, path, &vaf);
590 	va_end(args);
591 
592 	ext4_handle_error(inode->i_sb);
593 }
594 
595 static const char *ext4_decode_error(struct super_block *sb, int errno,
596 				     char nbuf[16])
597 {
598 	char *errstr = NULL;
599 
600 	switch (errno) {
601 	case -EIO:
602 		errstr = "IO failure";
603 		break;
604 	case -ENOMEM:
605 		errstr = "Out of memory";
606 		break;
607 	case -EROFS:
608 		if (!sb || (EXT4_SB(sb)->s_journal &&
609 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
610 			errstr = "Journal has aborted";
611 		else
612 			errstr = "Readonly filesystem";
613 		break;
614 	default:
615 		/* If the caller passed in an extra buffer for unknown
616 		 * errors, textualise them now.  Else we just return
617 		 * NULL. */
618 		if (nbuf) {
619 			/* Check for truncated error codes... */
620 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
621 				errstr = nbuf;
622 		}
623 		break;
624 	}
625 
626 	return errstr;
627 }
628 
629 /* __ext4_std_error decodes expected errors from journaling functions
630  * automatically and invokes the appropriate error response.  */
631 
632 void __ext4_std_error(struct super_block *sb, const char *function,
633 		      unsigned int line, int errno)
634 {
635 	char nbuf[16];
636 	const char *errstr;
637 
638 	/* Special case: if the error is EROFS, and we're not already
639 	 * inside a transaction, then there's really no point in logging
640 	 * an error. */
641 	if (errno == -EROFS && journal_current_handle() == NULL &&
642 	    (sb->s_flags & MS_RDONLY))
643 		return;
644 
645 	errstr = ext4_decode_error(sb, errno, nbuf);
646 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
647 	       sb->s_id, function, line, errstr);
648 	save_error_info(sb, function, line);
649 
650 	ext4_handle_error(sb);
651 }
652 
653 /*
654  * ext4_abort is a much stronger failure handler than ext4_error.  The
655  * abort function may be used to deal with unrecoverable failures such
656  * as journal IO errors or ENOMEM at a critical moment in log management.
657  *
658  * We unconditionally force the filesystem into an ABORT|READONLY state,
659  * unless the error response on the fs has been set to panic in which
660  * case we take the easy way out and panic immediately.
661  */
662 
663 void __ext4_abort(struct super_block *sb, const char *function,
664 		unsigned int line, const char *fmt, ...)
665 {
666 	va_list args;
667 
668 	save_error_info(sb, function, line);
669 	va_start(args, fmt);
670 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
671 	       function, line);
672 	vprintk(fmt, args);
673 	printk("\n");
674 	va_end(args);
675 
676 	if ((sb->s_flags & MS_RDONLY) == 0) {
677 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
678 		sb->s_flags |= MS_RDONLY;
679 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
680 		if (EXT4_SB(sb)->s_journal)
681 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
682 		save_error_info(sb, function, line);
683 	}
684 	if (test_opt(sb, ERRORS_PANIC))
685 		panic("EXT4-fs panic from previous error\n");
686 }
687 
688 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
689 {
690 	struct va_format vaf;
691 	va_list args;
692 
693 	va_start(args, fmt);
694 	vaf.fmt = fmt;
695 	vaf.va = &args;
696 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
697 	va_end(args);
698 }
699 
700 void __ext4_warning(struct super_block *sb, const char *function,
701 		    unsigned int line, const char *fmt, ...)
702 {
703 	struct va_format vaf;
704 	va_list args;
705 
706 	va_start(args, fmt);
707 	vaf.fmt = fmt;
708 	vaf.va = &args;
709 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
710 	       sb->s_id, function, line, &vaf);
711 	va_end(args);
712 }
713 
714 void __ext4_grp_locked_error(const char *function, unsigned int line,
715 			     struct super_block *sb, ext4_group_t grp,
716 			     unsigned long ino, ext4_fsblk_t block,
717 			     const char *fmt, ...)
718 __releases(bitlock)
719 __acquires(bitlock)
720 {
721 	struct va_format vaf;
722 	va_list args;
723 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
724 
725 	es->s_last_error_ino = cpu_to_le32(ino);
726 	es->s_last_error_block = cpu_to_le64(block);
727 	__save_error_info(sb, function, line);
728 
729 	va_start(args, fmt);
730 
731 	vaf.fmt = fmt;
732 	vaf.va = &args;
733 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
734 	       sb->s_id, function, line, grp);
735 	if (ino)
736 		printk(KERN_CONT "inode %lu: ", ino);
737 	if (block)
738 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
739 	printk(KERN_CONT "%pV\n", &vaf);
740 	va_end(args);
741 
742 	if (test_opt(sb, ERRORS_CONT)) {
743 		ext4_commit_super(sb, 0);
744 		return;
745 	}
746 
747 	ext4_unlock_group(sb, grp);
748 	ext4_handle_error(sb);
749 	/*
750 	 * We only get here in the ERRORS_RO case; relocking the group
751 	 * may be dangerous, but nothing bad will happen since the
752 	 * filesystem will have already been marked read/only and the
753 	 * journal has been aborted.  We return 1 as a hint to callers
754 	 * who might what to use the return value from
755 	 * ext4_grp_locked_error() to distinguish between the
756 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
757 	 * aggressively from the ext4 function in question, with a
758 	 * more appropriate error code.
759 	 */
760 	ext4_lock_group(sb, grp);
761 	return;
762 }
763 
764 void ext4_update_dynamic_rev(struct super_block *sb)
765 {
766 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
767 
768 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
769 		return;
770 
771 	ext4_warning(sb,
772 		     "updating to rev %d because of new feature flag, "
773 		     "running e2fsck is recommended",
774 		     EXT4_DYNAMIC_REV);
775 
776 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
777 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
778 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
779 	/* leave es->s_feature_*compat flags alone */
780 	/* es->s_uuid will be set by e2fsck if empty */
781 
782 	/*
783 	 * The rest of the superblock fields should be zero, and if not it
784 	 * means they are likely already in use, so leave them alone.  We
785 	 * can leave it up to e2fsck to clean up any inconsistencies there.
786 	 */
787 }
788 
789 /*
790  * Open the external journal device
791  */
792 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
793 {
794 	struct block_device *bdev;
795 	char b[BDEVNAME_SIZE];
796 
797 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
798 	if (IS_ERR(bdev))
799 		goto fail;
800 	return bdev;
801 
802 fail:
803 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
804 			__bdevname(dev, b), PTR_ERR(bdev));
805 	return NULL;
806 }
807 
808 /*
809  * Release the journal device
810  */
811 static int ext4_blkdev_put(struct block_device *bdev)
812 {
813 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
814 }
815 
816 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
817 {
818 	struct block_device *bdev;
819 	int ret = -ENODEV;
820 
821 	bdev = sbi->journal_bdev;
822 	if (bdev) {
823 		ret = ext4_blkdev_put(bdev);
824 		sbi->journal_bdev = NULL;
825 	}
826 	return ret;
827 }
828 
829 static inline struct inode *orphan_list_entry(struct list_head *l)
830 {
831 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
832 }
833 
834 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
835 {
836 	struct list_head *l;
837 
838 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
839 		 le32_to_cpu(sbi->s_es->s_last_orphan));
840 
841 	printk(KERN_ERR "sb_info orphan list:\n");
842 	list_for_each(l, &sbi->s_orphan) {
843 		struct inode *inode = orphan_list_entry(l);
844 		printk(KERN_ERR "  "
845 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
846 		       inode->i_sb->s_id, inode->i_ino, inode,
847 		       inode->i_mode, inode->i_nlink,
848 		       NEXT_ORPHAN(inode));
849 	}
850 }
851 
852 static void ext4_put_super(struct super_block *sb)
853 {
854 	struct ext4_sb_info *sbi = EXT4_SB(sb);
855 	struct ext4_super_block *es = sbi->s_es;
856 	int i, err;
857 
858 	ext4_unregister_li_request(sb);
859 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
860 
861 	flush_workqueue(sbi->dio_unwritten_wq);
862 	destroy_workqueue(sbi->dio_unwritten_wq);
863 
864 	lock_super(sb);
865 	if (sbi->s_journal) {
866 		err = jbd2_journal_destroy(sbi->s_journal);
867 		sbi->s_journal = NULL;
868 		if (err < 0)
869 			ext4_abort(sb, "Couldn't clean up the journal");
870 	}
871 
872 	del_timer(&sbi->s_err_report);
873 	ext4_release_system_zone(sb);
874 	ext4_mb_release(sb);
875 	ext4_ext_release(sb);
876 	ext4_xattr_put_super(sb);
877 
878 	if (!(sb->s_flags & MS_RDONLY)) {
879 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
880 		es->s_state = cpu_to_le16(sbi->s_mount_state);
881 	}
882 	if (!(sb->s_flags & MS_RDONLY))
883 		ext4_commit_super(sb, 1);
884 
885 	if (sbi->s_proc) {
886 		remove_proc_entry("options", sbi->s_proc);
887 		remove_proc_entry(sb->s_id, ext4_proc_root);
888 	}
889 	kobject_del(&sbi->s_kobj);
890 
891 	for (i = 0; i < sbi->s_gdb_count; i++)
892 		brelse(sbi->s_group_desc[i]);
893 	ext4_kvfree(sbi->s_group_desc);
894 	ext4_kvfree(sbi->s_flex_groups);
895 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
896 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
897 	percpu_counter_destroy(&sbi->s_dirs_counter);
898 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
899 	brelse(sbi->s_sbh);
900 #ifdef CONFIG_QUOTA
901 	for (i = 0; i < MAXQUOTAS; i++)
902 		kfree(sbi->s_qf_names[i]);
903 #endif
904 
905 	/* Debugging code just in case the in-memory inode orphan list
906 	 * isn't empty.  The on-disk one can be non-empty if we've
907 	 * detected an error and taken the fs readonly, but the
908 	 * in-memory list had better be clean by this point. */
909 	if (!list_empty(&sbi->s_orphan))
910 		dump_orphan_list(sb, sbi);
911 	J_ASSERT(list_empty(&sbi->s_orphan));
912 
913 	invalidate_bdev(sb->s_bdev);
914 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
915 		/*
916 		 * Invalidate the journal device's buffers.  We don't want them
917 		 * floating about in memory - the physical journal device may
918 		 * hotswapped, and it breaks the `ro-after' testing code.
919 		 */
920 		sync_blockdev(sbi->journal_bdev);
921 		invalidate_bdev(sbi->journal_bdev);
922 		ext4_blkdev_remove(sbi);
923 	}
924 	if (sbi->s_mmp_tsk)
925 		kthread_stop(sbi->s_mmp_tsk);
926 	sb->s_fs_info = NULL;
927 	/*
928 	 * Now that we are completely done shutting down the
929 	 * superblock, we need to actually destroy the kobject.
930 	 */
931 	unlock_super(sb);
932 	kobject_put(&sbi->s_kobj);
933 	wait_for_completion(&sbi->s_kobj_unregister);
934 	if (sbi->s_chksum_driver)
935 		crypto_free_shash(sbi->s_chksum_driver);
936 	kfree(sbi->s_blockgroup_lock);
937 	kfree(sbi);
938 }
939 
940 static struct kmem_cache *ext4_inode_cachep;
941 
942 /*
943  * Called inside transaction, so use GFP_NOFS
944  */
945 static struct inode *ext4_alloc_inode(struct super_block *sb)
946 {
947 	struct ext4_inode_info *ei;
948 
949 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
950 	if (!ei)
951 		return NULL;
952 
953 	ei->vfs_inode.i_version = 1;
954 	ei->vfs_inode.i_data.writeback_index = 0;
955 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
956 	INIT_LIST_HEAD(&ei->i_prealloc_list);
957 	spin_lock_init(&ei->i_prealloc_lock);
958 	ei->i_reserved_data_blocks = 0;
959 	ei->i_reserved_meta_blocks = 0;
960 	ei->i_allocated_meta_blocks = 0;
961 	ei->i_da_metadata_calc_len = 0;
962 	spin_lock_init(&(ei->i_block_reservation_lock));
963 #ifdef CONFIG_QUOTA
964 	ei->i_reserved_quota = 0;
965 #endif
966 	ei->jinode = NULL;
967 	INIT_LIST_HEAD(&ei->i_completed_io_list);
968 	spin_lock_init(&ei->i_completed_io_lock);
969 	ei->cur_aio_dio = NULL;
970 	ei->i_sync_tid = 0;
971 	ei->i_datasync_tid = 0;
972 	atomic_set(&ei->i_ioend_count, 0);
973 	atomic_set(&ei->i_aiodio_unwritten, 0);
974 
975 	return &ei->vfs_inode;
976 }
977 
978 static int ext4_drop_inode(struct inode *inode)
979 {
980 	int drop = generic_drop_inode(inode);
981 
982 	trace_ext4_drop_inode(inode, drop);
983 	return drop;
984 }
985 
986 static void ext4_i_callback(struct rcu_head *head)
987 {
988 	struct inode *inode = container_of(head, struct inode, i_rcu);
989 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
990 }
991 
992 static void ext4_destroy_inode(struct inode *inode)
993 {
994 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
995 		ext4_msg(inode->i_sb, KERN_ERR,
996 			 "Inode %lu (%p): orphan list check failed!",
997 			 inode->i_ino, EXT4_I(inode));
998 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
999 				EXT4_I(inode), sizeof(struct ext4_inode_info),
1000 				true);
1001 		dump_stack();
1002 	}
1003 	call_rcu(&inode->i_rcu, ext4_i_callback);
1004 }
1005 
1006 static void init_once(void *foo)
1007 {
1008 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
1009 
1010 	INIT_LIST_HEAD(&ei->i_orphan);
1011 #ifdef CONFIG_EXT4_FS_XATTR
1012 	init_rwsem(&ei->xattr_sem);
1013 #endif
1014 	init_rwsem(&ei->i_data_sem);
1015 	inode_init_once(&ei->vfs_inode);
1016 }
1017 
1018 static int init_inodecache(void)
1019 {
1020 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1021 					     sizeof(struct ext4_inode_info),
1022 					     0, (SLAB_RECLAIM_ACCOUNT|
1023 						SLAB_MEM_SPREAD),
1024 					     init_once);
1025 	if (ext4_inode_cachep == NULL)
1026 		return -ENOMEM;
1027 	return 0;
1028 }
1029 
1030 static void destroy_inodecache(void)
1031 {
1032 	kmem_cache_destroy(ext4_inode_cachep);
1033 }
1034 
1035 void ext4_clear_inode(struct inode *inode)
1036 {
1037 	invalidate_inode_buffers(inode);
1038 	clear_inode(inode);
1039 	dquot_drop(inode);
1040 	ext4_discard_preallocations(inode);
1041 	if (EXT4_I(inode)->jinode) {
1042 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1043 					       EXT4_I(inode)->jinode);
1044 		jbd2_free_inode(EXT4_I(inode)->jinode);
1045 		EXT4_I(inode)->jinode = NULL;
1046 	}
1047 }
1048 
1049 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1050 					u64 ino, u32 generation)
1051 {
1052 	struct inode *inode;
1053 
1054 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1055 		return ERR_PTR(-ESTALE);
1056 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1057 		return ERR_PTR(-ESTALE);
1058 
1059 	/* iget isn't really right if the inode is currently unallocated!!
1060 	 *
1061 	 * ext4_read_inode will return a bad_inode if the inode had been
1062 	 * deleted, so we should be safe.
1063 	 *
1064 	 * Currently we don't know the generation for parent directory, so
1065 	 * a generation of 0 means "accept any"
1066 	 */
1067 	inode = ext4_iget(sb, ino);
1068 	if (IS_ERR(inode))
1069 		return ERR_CAST(inode);
1070 	if (generation && inode->i_generation != generation) {
1071 		iput(inode);
1072 		return ERR_PTR(-ESTALE);
1073 	}
1074 
1075 	return inode;
1076 }
1077 
1078 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1079 					int fh_len, int fh_type)
1080 {
1081 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1082 				    ext4_nfs_get_inode);
1083 }
1084 
1085 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1086 					int fh_len, int fh_type)
1087 {
1088 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1089 				    ext4_nfs_get_inode);
1090 }
1091 
1092 /*
1093  * Try to release metadata pages (indirect blocks, directories) which are
1094  * mapped via the block device.  Since these pages could have journal heads
1095  * which would prevent try_to_free_buffers() from freeing them, we must use
1096  * jbd2 layer's try_to_free_buffers() function to release them.
1097  */
1098 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1099 				 gfp_t wait)
1100 {
1101 	journal_t *journal = EXT4_SB(sb)->s_journal;
1102 
1103 	WARN_ON(PageChecked(page));
1104 	if (!page_has_buffers(page))
1105 		return 0;
1106 	if (journal)
1107 		return jbd2_journal_try_to_free_buffers(journal, page,
1108 							wait & ~__GFP_WAIT);
1109 	return try_to_free_buffers(page);
1110 }
1111 
1112 #ifdef CONFIG_QUOTA
1113 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1114 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1115 
1116 static int ext4_write_dquot(struct dquot *dquot);
1117 static int ext4_acquire_dquot(struct dquot *dquot);
1118 static int ext4_release_dquot(struct dquot *dquot);
1119 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1120 static int ext4_write_info(struct super_block *sb, int type);
1121 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1122 			 struct path *path);
1123 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1124 				 int format_id);
1125 static int ext4_quota_off(struct super_block *sb, int type);
1126 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1127 static int ext4_quota_on_mount(struct super_block *sb, int type);
1128 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1129 			       size_t len, loff_t off);
1130 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1131 				const char *data, size_t len, loff_t off);
1132 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1133 			     unsigned int flags);
1134 static int ext4_enable_quotas(struct super_block *sb);
1135 
1136 static const struct dquot_operations ext4_quota_operations = {
1137 	.get_reserved_space = ext4_get_reserved_space,
1138 	.write_dquot	= ext4_write_dquot,
1139 	.acquire_dquot	= ext4_acquire_dquot,
1140 	.release_dquot	= ext4_release_dquot,
1141 	.mark_dirty	= ext4_mark_dquot_dirty,
1142 	.write_info	= ext4_write_info,
1143 	.alloc_dquot	= dquot_alloc,
1144 	.destroy_dquot	= dquot_destroy,
1145 };
1146 
1147 static const struct quotactl_ops ext4_qctl_operations = {
1148 	.quota_on	= ext4_quota_on,
1149 	.quota_off	= ext4_quota_off,
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 
1157 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1158 	.quota_on_meta	= ext4_quota_on_sysfile,
1159 	.quota_off	= ext4_quota_off_sysfile,
1160 	.quota_sync	= dquot_quota_sync,
1161 	.get_info	= dquot_get_dqinfo,
1162 	.set_info	= dquot_set_dqinfo,
1163 	.get_dqblk	= dquot_get_dqblk,
1164 	.set_dqblk	= dquot_set_dqblk
1165 };
1166 #endif
1167 
1168 static const struct super_operations ext4_sops = {
1169 	.alloc_inode	= ext4_alloc_inode,
1170 	.destroy_inode	= ext4_destroy_inode,
1171 	.write_inode	= ext4_write_inode,
1172 	.dirty_inode	= ext4_dirty_inode,
1173 	.drop_inode	= ext4_drop_inode,
1174 	.evict_inode	= ext4_evict_inode,
1175 	.put_super	= ext4_put_super,
1176 	.sync_fs	= ext4_sync_fs,
1177 	.freeze_fs	= ext4_freeze,
1178 	.unfreeze_fs	= ext4_unfreeze,
1179 	.statfs		= ext4_statfs,
1180 	.remount_fs	= ext4_remount,
1181 	.show_options	= ext4_show_options,
1182 #ifdef CONFIG_QUOTA
1183 	.quota_read	= ext4_quota_read,
1184 	.quota_write	= ext4_quota_write,
1185 #endif
1186 	.bdev_try_to_free_page = bdev_try_to_free_page,
1187 };
1188 
1189 static const struct super_operations ext4_nojournal_sops = {
1190 	.alloc_inode	= ext4_alloc_inode,
1191 	.destroy_inode	= ext4_destroy_inode,
1192 	.write_inode	= ext4_write_inode,
1193 	.dirty_inode	= ext4_dirty_inode,
1194 	.drop_inode	= ext4_drop_inode,
1195 	.evict_inode	= ext4_evict_inode,
1196 	.put_super	= ext4_put_super,
1197 	.statfs		= ext4_statfs,
1198 	.remount_fs	= ext4_remount,
1199 	.show_options	= ext4_show_options,
1200 #ifdef CONFIG_QUOTA
1201 	.quota_read	= ext4_quota_read,
1202 	.quota_write	= ext4_quota_write,
1203 #endif
1204 	.bdev_try_to_free_page = bdev_try_to_free_page,
1205 };
1206 
1207 static const struct export_operations ext4_export_ops = {
1208 	.fh_to_dentry = ext4_fh_to_dentry,
1209 	.fh_to_parent = ext4_fh_to_parent,
1210 	.get_parent = ext4_get_parent,
1211 };
1212 
1213 enum {
1214 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1215 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1216 	Opt_nouid32, Opt_debug, Opt_removed,
1217 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1218 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1219 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1220 	Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1221 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1222 	Opt_data_err_abort, Opt_data_err_ignore,
1223 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1224 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1225 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1226 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1227 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1228 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1229 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1230 	Opt_dioread_nolock, Opt_dioread_lock,
1231 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1232 };
1233 
1234 static const match_table_t tokens = {
1235 	{Opt_bsd_df, "bsddf"},
1236 	{Opt_minix_df, "minixdf"},
1237 	{Opt_grpid, "grpid"},
1238 	{Opt_grpid, "bsdgroups"},
1239 	{Opt_nogrpid, "nogrpid"},
1240 	{Opt_nogrpid, "sysvgroups"},
1241 	{Opt_resgid, "resgid=%u"},
1242 	{Opt_resuid, "resuid=%u"},
1243 	{Opt_sb, "sb=%u"},
1244 	{Opt_err_cont, "errors=continue"},
1245 	{Opt_err_panic, "errors=panic"},
1246 	{Opt_err_ro, "errors=remount-ro"},
1247 	{Opt_nouid32, "nouid32"},
1248 	{Opt_debug, "debug"},
1249 	{Opt_removed, "oldalloc"},
1250 	{Opt_removed, "orlov"},
1251 	{Opt_user_xattr, "user_xattr"},
1252 	{Opt_nouser_xattr, "nouser_xattr"},
1253 	{Opt_acl, "acl"},
1254 	{Opt_noacl, "noacl"},
1255 	{Opt_noload, "norecovery"},
1256 	{Opt_noload, "noload"},
1257 	{Opt_removed, "nobh"},
1258 	{Opt_removed, "bh"},
1259 	{Opt_commit, "commit=%u"},
1260 	{Opt_min_batch_time, "min_batch_time=%u"},
1261 	{Opt_max_batch_time, "max_batch_time=%u"},
1262 	{Opt_journal_dev, "journal_dev=%u"},
1263 	{Opt_journal_checksum, "journal_checksum"},
1264 	{Opt_journal_async_commit, "journal_async_commit"},
1265 	{Opt_abort, "abort"},
1266 	{Opt_data_journal, "data=journal"},
1267 	{Opt_data_ordered, "data=ordered"},
1268 	{Opt_data_writeback, "data=writeback"},
1269 	{Opt_data_err_abort, "data_err=abort"},
1270 	{Opt_data_err_ignore, "data_err=ignore"},
1271 	{Opt_offusrjquota, "usrjquota="},
1272 	{Opt_usrjquota, "usrjquota=%s"},
1273 	{Opt_offgrpjquota, "grpjquota="},
1274 	{Opt_grpjquota, "grpjquota=%s"},
1275 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1276 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1277 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1278 	{Opt_grpquota, "grpquota"},
1279 	{Opt_noquota, "noquota"},
1280 	{Opt_quota, "quota"},
1281 	{Opt_usrquota, "usrquota"},
1282 	{Opt_barrier, "barrier=%u"},
1283 	{Opt_barrier, "barrier"},
1284 	{Opt_nobarrier, "nobarrier"},
1285 	{Opt_i_version, "i_version"},
1286 	{Opt_stripe, "stripe=%u"},
1287 	{Opt_delalloc, "delalloc"},
1288 	{Opt_nodelalloc, "nodelalloc"},
1289 	{Opt_mblk_io_submit, "mblk_io_submit"},
1290 	{Opt_nomblk_io_submit, "nomblk_io_submit"},
1291 	{Opt_block_validity, "block_validity"},
1292 	{Opt_noblock_validity, "noblock_validity"},
1293 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1294 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1295 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1296 	{Opt_auto_da_alloc, "auto_da_alloc"},
1297 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1298 	{Opt_dioread_nolock, "dioread_nolock"},
1299 	{Opt_dioread_lock, "dioread_lock"},
1300 	{Opt_discard, "discard"},
1301 	{Opt_nodiscard, "nodiscard"},
1302 	{Opt_init_itable, "init_itable=%u"},
1303 	{Opt_init_itable, "init_itable"},
1304 	{Opt_noinit_itable, "noinit_itable"},
1305 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1306 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1307 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1308 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1309 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1310 	{Opt_err, NULL},
1311 };
1312 
1313 static ext4_fsblk_t get_sb_block(void **data)
1314 {
1315 	ext4_fsblk_t	sb_block;
1316 	char		*options = (char *) *data;
1317 
1318 	if (!options || strncmp(options, "sb=", 3) != 0)
1319 		return 1;	/* Default location */
1320 
1321 	options += 3;
1322 	/* TODO: use simple_strtoll with >32bit ext4 */
1323 	sb_block = simple_strtoul(options, &options, 0);
1324 	if (*options && *options != ',') {
1325 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1326 		       (char *) *data);
1327 		return 1;
1328 	}
1329 	if (*options == ',')
1330 		options++;
1331 	*data = (void *) options;
1332 
1333 	return sb_block;
1334 }
1335 
1336 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1337 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1338 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1339 
1340 #ifdef CONFIG_QUOTA
1341 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1342 {
1343 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1344 	char *qname;
1345 
1346 	if (sb_any_quota_loaded(sb) &&
1347 		!sbi->s_qf_names[qtype]) {
1348 		ext4_msg(sb, KERN_ERR,
1349 			"Cannot change journaled "
1350 			"quota options when quota turned on");
1351 		return -1;
1352 	}
1353 	qname = match_strdup(args);
1354 	if (!qname) {
1355 		ext4_msg(sb, KERN_ERR,
1356 			"Not enough memory for storing quotafile name");
1357 		return -1;
1358 	}
1359 	if (sbi->s_qf_names[qtype] &&
1360 		strcmp(sbi->s_qf_names[qtype], qname)) {
1361 		ext4_msg(sb, KERN_ERR,
1362 			"%s quota file already specified", QTYPE2NAME(qtype));
1363 		kfree(qname);
1364 		return -1;
1365 	}
1366 	sbi->s_qf_names[qtype] = qname;
1367 	if (strchr(sbi->s_qf_names[qtype], '/')) {
1368 		ext4_msg(sb, KERN_ERR,
1369 			"quotafile must be on filesystem root");
1370 		kfree(sbi->s_qf_names[qtype]);
1371 		sbi->s_qf_names[qtype] = NULL;
1372 		return -1;
1373 	}
1374 	set_opt(sb, QUOTA);
1375 	return 1;
1376 }
1377 
1378 static int clear_qf_name(struct super_block *sb, int qtype)
1379 {
1380 
1381 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1382 
1383 	if (sb_any_quota_loaded(sb) &&
1384 		sbi->s_qf_names[qtype]) {
1385 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1386 			" when quota turned on");
1387 		return -1;
1388 	}
1389 	/*
1390 	 * The space will be released later when all options are confirmed
1391 	 * to be correct
1392 	 */
1393 	sbi->s_qf_names[qtype] = NULL;
1394 	return 1;
1395 }
1396 #endif
1397 
1398 #define MOPT_SET	0x0001
1399 #define MOPT_CLEAR	0x0002
1400 #define MOPT_NOSUPPORT	0x0004
1401 #define MOPT_EXPLICIT	0x0008
1402 #define MOPT_CLEAR_ERR	0x0010
1403 #define MOPT_GTE0	0x0020
1404 #ifdef CONFIG_QUOTA
1405 #define MOPT_Q		0
1406 #define MOPT_QFMT	0x0040
1407 #else
1408 #define MOPT_Q		MOPT_NOSUPPORT
1409 #define MOPT_QFMT	MOPT_NOSUPPORT
1410 #endif
1411 #define MOPT_DATAJ	0x0080
1412 
1413 static const struct mount_opts {
1414 	int	token;
1415 	int	mount_opt;
1416 	int	flags;
1417 } ext4_mount_opts[] = {
1418 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1419 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1420 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1421 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1422 	{Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
1423 	{Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
1424 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1425 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1426 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
1427 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_CLEAR},
1428 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1429 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1430 	{Opt_delalloc, EXT4_MOUNT_DELALLOC, MOPT_SET | MOPT_EXPLICIT},
1431 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC, MOPT_CLEAR | MOPT_EXPLICIT},
1432 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM, MOPT_SET},
1433 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1434 				    EXT4_MOUNT_JOURNAL_CHECKSUM), MOPT_SET},
1435 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_SET},
1436 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1437 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1438 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1439 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_SET},
1440 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_CLEAR},
1441 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1442 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1443 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1444 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1445 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1446 	{Opt_commit, 0, MOPT_GTE0},
1447 	{Opt_max_batch_time, 0, MOPT_GTE0},
1448 	{Opt_min_batch_time, 0, MOPT_GTE0},
1449 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1450 	{Opt_init_itable, 0, MOPT_GTE0},
1451 	{Opt_stripe, 0, MOPT_GTE0},
1452 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
1453 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
1454 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
1455 #ifdef CONFIG_EXT4_FS_XATTR
1456 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1457 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1458 #else
1459 	{Opt_user_xattr, 0, MOPT_NOSUPPORT},
1460 	{Opt_nouser_xattr, 0, MOPT_NOSUPPORT},
1461 #endif
1462 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1463 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1464 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1465 #else
1466 	{Opt_acl, 0, MOPT_NOSUPPORT},
1467 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1468 #endif
1469 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1470 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1471 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1472 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1473 							MOPT_SET | MOPT_Q},
1474 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1475 							MOPT_SET | MOPT_Q},
1476 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1477 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1478 	{Opt_usrjquota, 0, MOPT_Q},
1479 	{Opt_grpjquota, 0, MOPT_Q},
1480 	{Opt_offusrjquota, 0, MOPT_Q},
1481 	{Opt_offgrpjquota, 0, MOPT_Q},
1482 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1483 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1484 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1485 	{Opt_err, 0, 0}
1486 };
1487 
1488 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1489 			    substring_t *args, unsigned long *journal_devnum,
1490 			    unsigned int *journal_ioprio, int is_remount)
1491 {
1492 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1493 	const struct mount_opts *m;
1494 	kuid_t uid;
1495 	kgid_t gid;
1496 	int arg = 0;
1497 
1498 #ifdef CONFIG_QUOTA
1499 	if (token == Opt_usrjquota)
1500 		return set_qf_name(sb, USRQUOTA, &args[0]);
1501 	else if (token == Opt_grpjquota)
1502 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1503 	else if (token == Opt_offusrjquota)
1504 		return clear_qf_name(sb, USRQUOTA);
1505 	else if (token == Opt_offgrpjquota)
1506 		return clear_qf_name(sb, GRPQUOTA);
1507 #endif
1508 	if (args->from && match_int(args, &arg))
1509 		return -1;
1510 	switch (token) {
1511 	case Opt_noacl:
1512 	case Opt_nouser_xattr:
1513 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1514 		break;
1515 	case Opt_sb:
1516 		return 1;	/* handled by get_sb_block() */
1517 	case Opt_removed:
1518 		ext4_msg(sb, KERN_WARNING,
1519 			 "Ignoring removed %s option", opt);
1520 		return 1;
1521 	case Opt_resuid:
1522 		uid = make_kuid(current_user_ns(), arg);
1523 		if (!uid_valid(uid)) {
1524 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1525 			return -1;
1526 		}
1527 		sbi->s_resuid = uid;
1528 		return 1;
1529 	case Opt_resgid:
1530 		gid = make_kgid(current_user_ns(), arg);
1531 		if (!gid_valid(gid)) {
1532 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1533 			return -1;
1534 		}
1535 		sbi->s_resgid = gid;
1536 		return 1;
1537 	case Opt_abort:
1538 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1539 		return 1;
1540 	case Opt_i_version:
1541 		sb->s_flags |= MS_I_VERSION;
1542 		return 1;
1543 	case Opt_journal_dev:
1544 		if (is_remount) {
1545 			ext4_msg(sb, KERN_ERR,
1546 				 "Cannot specify journal on remount");
1547 			return -1;
1548 		}
1549 		*journal_devnum = arg;
1550 		return 1;
1551 	case Opt_journal_ioprio:
1552 		if (arg < 0 || arg > 7)
1553 			return -1;
1554 		*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1555 		return 1;
1556 	}
1557 
1558 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1559 		if (token != m->token)
1560 			continue;
1561 		if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1562 			return -1;
1563 		if (m->flags & MOPT_EXPLICIT)
1564 			set_opt2(sb, EXPLICIT_DELALLOC);
1565 		if (m->flags & MOPT_CLEAR_ERR)
1566 			clear_opt(sb, ERRORS_MASK);
1567 		if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1568 			ext4_msg(sb, KERN_ERR, "Cannot change quota "
1569 				 "options when quota turned on");
1570 			return -1;
1571 		}
1572 
1573 		if (m->flags & MOPT_NOSUPPORT) {
1574 			ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1575 		} else if (token == Opt_commit) {
1576 			if (arg == 0)
1577 				arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1578 			sbi->s_commit_interval = HZ * arg;
1579 		} else if (token == Opt_max_batch_time) {
1580 			if (arg == 0)
1581 				arg = EXT4_DEF_MAX_BATCH_TIME;
1582 			sbi->s_max_batch_time = arg;
1583 		} else if (token == Opt_min_batch_time) {
1584 			sbi->s_min_batch_time = arg;
1585 		} else if (token == Opt_inode_readahead_blks) {
1586 			if (arg > (1 << 30))
1587 				return -1;
1588 			if (arg && !is_power_of_2(arg)) {
1589 				ext4_msg(sb, KERN_ERR,
1590 					 "EXT4-fs: inode_readahead_blks"
1591 					 " must be a power of 2");
1592 				return -1;
1593 			}
1594 			sbi->s_inode_readahead_blks = arg;
1595 		} else if (token == Opt_init_itable) {
1596 			set_opt(sb, INIT_INODE_TABLE);
1597 			if (!args->from)
1598 				arg = EXT4_DEF_LI_WAIT_MULT;
1599 			sbi->s_li_wait_mult = arg;
1600 		} else if (token == Opt_stripe) {
1601 			sbi->s_stripe = arg;
1602 		} else if (m->flags & MOPT_DATAJ) {
1603 			if (is_remount) {
1604 				if (!sbi->s_journal)
1605 					ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1606 				else if (test_opt(sb, DATA_FLAGS) !=
1607 					 m->mount_opt) {
1608 					ext4_msg(sb, KERN_ERR,
1609 					 "Cannot change data mode on remount");
1610 					return -1;
1611 				}
1612 			} else {
1613 				clear_opt(sb, DATA_FLAGS);
1614 				sbi->s_mount_opt |= m->mount_opt;
1615 			}
1616 #ifdef CONFIG_QUOTA
1617 		} else if (m->flags & MOPT_QFMT) {
1618 			if (sb_any_quota_loaded(sb) &&
1619 			    sbi->s_jquota_fmt != m->mount_opt) {
1620 				ext4_msg(sb, KERN_ERR, "Cannot "
1621 					 "change journaled quota options "
1622 					 "when quota turned on");
1623 				return -1;
1624 			}
1625 			sbi->s_jquota_fmt = m->mount_opt;
1626 #endif
1627 		} else {
1628 			if (!args->from)
1629 				arg = 1;
1630 			if (m->flags & MOPT_CLEAR)
1631 				arg = !arg;
1632 			else if (unlikely(!(m->flags & MOPT_SET))) {
1633 				ext4_msg(sb, KERN_WARNING,
1634 					 "buggy handling of option %s", opt);
1635 				WARN_ON(1);
1636 				return -1;
1637 			}
1638 			if (arg != 0)
1639 				sbi->s_mount_opt |= m->mount_opt;
1640 			else
1641 				sbi->s_mount_opt &= ~m->mount_opt;
1642 		}
1643 		return 1;
1644 	}
1645 	ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1646 		 "or missing value", opt);
1647 	return -1;
1648 }
1649 
1650 static int parse_options(char *options, struct super_block *sb,
1651 			 unsigned long *journal_devnum,
1652 			 unsigned int *journal_ioprio,
1653 			 int is_remount)
1654 {
1655 #ifdef CONFIG_QUOTA
1656 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1657 #endif
1658 	char *p;
1659 	substring_t args[MAX_OPT_ARGS];
1660 	int token;
1661 
1662 	if (!options)
1663 		return 1;
1664 
1665 	while ((p = strsep(&options, ",")) != NULL) {
1666 		if (!*p)
1667 			continue;
1668 		/*
1669 		 * Initialize args struct so we know whether arg was
1670 		 * found; some options take optional arguments.
1671 		 */
1672 		args[0].to = args[0].from = 0;
1673 		token = match_token(p, tokens, args);
1674 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1675 				     journal_ioprio, is_remount) < 0)
1676 			return 0;
1677 	}
1678 #ifdef CONFIG_QUOTA
1679 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1680 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1681 			clear_opt(sb, USRQUOTA);
1682 
1683 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1684 			clear_opt(sb, GRPQUOTA);
1685 
1686 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1687 			ext4_msg(sb, KERN_ERR, "old and new quota "
1688 					"format mixing");
1689 			return 0;
1690 		}
1691 
1692 		if (!sbi->s_jquota_fmt) {
1693 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1694 					"not specified");
1695 			return 0;
1696 		}
1697 	} else {
1698 		if (sbi->s_jquota_fmt) {
1699 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1700 					"specified with no journaling "
1701 					"enabled");
1702 			return 0;
1703 		}
1704 	}
1705 #endif
1706 	return 1;
1707 }
1708 
1709 static inline void ext4_show_quota_options(struct seq_file *seq,
1710 					   struct super_block *sb)
1711 {
1712 #if defined(CONFIG_QUOTA)
1713 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1714 
1715 	if (sbi->s_jquota_fmt) {
1716 		char *fmtname = "";
1717 
1718 		switch (sbi->s_jquota_fmt) {
1719 		case QFMT_VFS_OLD:
1720 			fmtname = "vfsold";
1721 			break;
1722 		case QFMT_VFS_V0:
1723 			fmtname = "vfsv0";
1724 			break;
1725 		case QFMT_VFS_V1:
1726 			fmtname = "vfsv1";
1727 			break;
1728 		}
1729 		seq_printf(seq, ",jqfmt=%s", fmtname);
1730 	}
1731 
1732 	if (sbi->s_qf_names[USRQUOTA])
1733 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1734 
1735 	if (sbi->s_qf_names[GRPQUOTA])
1736 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1737 
1738 	if (test_opt(sb, USRQUOTA))
1739 		seq_puts(seq, ",usrquota");
1740 
1741 	if (test_opt(sb, GRPQUOTA))
1742 		seq_puts(seq, ",grpquota");
1743 #endif
1744 }
1745 
1746 static const char *token2str(int token)
1747 {
1748 	static const struct match_token *t;
1749 
1750 	for (t = tokens; t->token != Opt_err; t++)
1751 		if (t->token == token && !strchr(t->pattern, '='))
1752 			break;
1753 	return t->pattern;
1754 }
1755 
1756 /*
1757  * Show an option if
1758  *  - it's set to a non-default value OR
1759  *  - if the per-sb default is different from the global default
1760  */
1761 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1762 			      int nodefs)
1763 {
1764 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1765 	struct ext4_super_block *es = sbi->s_es;
1766 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1767 	const struct mount_opts *m;
1768 	char sep = nodefs ? '\n' : ',';
1769 
1770 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1771 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1772 
1773 	if (sbi->s_sb_block != 1)
1774 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1775 
1776 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1777 		int want_set = m->flags & MOPT_SET;
1778 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1779 		    (m->flags & MOPT_CLEAR_ERR))
1780 			continue;
1781 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1782 			continue; /* skip if same as the default */
1783 		if ((want_set &&
1784 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1785 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1786 			continue; /* select Opt_noFoo vs Opt_Foo */
1787 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1788 	}
1789 
1790 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1791 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1792 		SEQ_OPTS_PRINT("resuid=%u",
1793 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1794 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1795 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1796 		SEQ_OPTS_PRINT("resgid=%u",
1797 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1798 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1799 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1800 		SEQ_OPTS_PUTS("errors=remount-ro");
1801 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1802 		SEQ_OPTS_PUTS("errors=continue");
1803 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1804 		SEQ_OPTS_PUTS("errors=panic");
1805 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1806 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1807 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1808 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1809 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1810 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1811 	if (sb->s_flags & MS_I_VERSION)
1812 		SEQ_OPTS_PUTS("i_version");
1813 	if (nodefs || sbi->s_stripe)
1814 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1815 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1816 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1817 			SEQ_OPTS_PUTS("data=journal");
1818 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1819 			SEQ_OPTS_PUTS("data=ordered");
1820 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1821 			SEQ_OPTS_PUTS("data=writeback");
1822 	}
1823 	if (nodefs ||
1824 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1825 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1826 			       sbi->s_inode_readahead_blks);
1827 
1828 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1829 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1830 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1831 
1832 	ext4_show_quota_options(seq, sb);
1833 	return 0;
1834 }
1835 
1836 static int ext4_show_options(struct seq_file *seq, struct dentry *root)
1837 {
1838 	return _ext4_show_options(seq, root->d_sb, 0);
1839 }
1840 
1841 static int options_seq_show(struct seq_file *seq, void *offset)
1842 {
1843 	struct super_block *sb = seq->private;
1844 	int rc;
1845 
1846 	seq_puts(seq, (sb->s_flags & MS_RDONLY) ? "ro" : "rw");
1847 	rc = _ext4_show_options(seq, sb, 1);
1848 	seq_puts(seq, "\n");
1849 	return rc;
1850 }
1851 
1852 static int options_open_fs(struct inode *inode, struct file *file)
1853 {
1854 	return single_open(file, options_seq_show, PDE(inode)->data);
1855 }
1856 
1857 static const struct file_operations ext4_seq_options_fops = {
1858 	.owner = THIS_MODULE,
1859 	.open = options_open_fs,
1860 	.read = seq_read,
1861 	.llseek = seq_lseek,
1862 	.release = single_release,
1863 };
1864 
1865 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1866 			    int read_only)
1867 {
1868 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1869 	int res = 0;
1870 
1871 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1872 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1873 			 "forcing read-only mode");
1874 		res = MS_RDONLY;
1875 	}
1876 	if (read_only)
1877 		goto done;
1878 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1879 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1880 			 "running e2fsck is recommended");
1881 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1882 		ext4_msg(sb, KERN_WARNING,
1883 			 "warning: mounting fs with errors, "
1884 			 "running e2fsck is recommended");
1885 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) > 0 &&
1886 		 le16_to_cpu(es->s_mnt_count) >=
1887 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1888 		ext4_msg(sb, KERN_WARNING,
1889 			 "warning: maximal mount count reached, "
1890 			 "running e2fsck is recommended");
1891 	else if (le32_to_cpu(es->s_checkinterval) &&
1892 		(le32_to_cpu(es->s_lastcheck) +
1893 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1894 		ext4_msg(sb, KERN_WARNING,
1895 			 "warning: checktime reached, "
1896 			 "running e2fsck is recommended");
1897 	if (!sbi->s_journal)
1898 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1899 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1900 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1901 	le16_add_cpu(&es->s_mnt_count, 1);
1902 	es->s_mtime = cpu_to_le32(get_seconds());
1903 	ext4_update_dynamic_rev(sb);
1904 	if (sbi->s_journal)
1905 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1906 
1907 	ext4_commit_super(sb, 1);
1908 done:
1909 	if (test_opt(sb, DEBUG))
1910 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1911 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1912 			sb->s_blocksize,
1913 			sbi->s_groups_count,
1914 			EXT4_BLOCKS_PER_GROUP(sb),
1915 			EXT4_INODES_PER_GROUP(sb),
1916 			sbi->s_mount_opt, sbi->s_mount_opt2);
1917 
1918 	cleancache_init_fs(sb);
1919 	return res;
1920 }
1921 
1922 static int ext4_fill_flex_info(struct super_block *sb)
1923 {
1924 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1925 	struct ext4_group_desc *gdp = NULL;
1926 	ext4_group_t flex_group_count;
1927 	ext4_group_t flex_group;
1928 	unsigned int groups_per_flex = 0;
1929 	size_t size;
1930 	int i;
1931 
1932 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1933 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1934 		sbi->s_log_groups_per_flex = 0;
1935 		return 1;
1936 	}
1937 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1938 
1939 	/* We allocate both existing and potentially added groups */
1940 	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1941 			((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1942 			      EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1943 	size = flex_group_count * sizeof(struct flex_groups);
1944 	sbi->s_flex_groups = ext4_kvzalloc(size, GFP_KERNEL);
1945 	if (sbi->s_flex_groups == NULL) {
1946 		ext4_msg(sb, KERN_ERR, "not enough memory for %u flex groups",
1947 			 flex_group_count);
1948 		goto failed;
1949 	}
1950 
1951 	for (i = 0; i < sbi->s_groups_count; i++) {
1952 		gdp = ext4_get_group_desc(sb, i, NULL);
1953 
1954 		flex_group = ext4_flex_group(sbi, i);
1955 		atomic_add(ext4_free_inodes_count(sb, gdp),
1956 			   &sbi->s_flex_groups[flex_group].free_inodes);
1957 		atomic_add(ext4_free_group_clusters(sb, gdp),
1958 			   &sbi->s_flex_groups[flex_group].free_clusters);
1959 		atomic_add(ext4_used_dirs_count(sb, gdp),
1960 			   &sbi->s_flex_groups[flex_group].used_dirs);
1961 	}
1962 
1963 	return 1;
1964 failed:
1965 	return 0;
1966 }
1967 
1968 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1969 				   struct ext4_group_desc *gdp)
1970 {
1971 	int offset;
1972 	__u16 crc = 0;
1973 	__le32 le_group = cpu_to_le32(block_group);
1974 
1975 	if ((sbi->s_es->s_feature_ro_compat &
1976 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1977 		/* Use new metadata_csum algorithm */
1978 		__u16 old_csum;
1979 		__u32 csum32;
1980 
1981 		old_csum = gdp->bg_checksum;
1982 		gdp->bg_checksum = 0;
1983 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
1984 				     sizeof(le_group));
1985 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
1986 				     sbi->s_desc_size);
1987 		gdp->bg_checksum = old_csum;
1988 
1989 		crc = csum32 & 0xFFFF;
1990 		goto out;
1991 	}
1992 
1993 	/* old crc16 code */
1994 	offset = offsetof(struct ext4_group_desc, bg_checksum);
1995 
1996 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1997 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1998 	crc = crc16(crc, (__u8 *)gdp, offset);
1999 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2000 	/* for checksum of struct ext4_group_desc do the rest...*/
2001 	if ((sbi->s_es->s_feature_incompat &
2002 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2003 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2004 		crc = crc16(crc, (__u8 *)gdp + offset,
2005 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2006 				offset);
2007 
2008 out:
2009 	return cpu_to_le16(crc);
2010 }
2011 
2012 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2013 				struct ext4_group_desc *gdp)
2014 {
2015 	if (ext4_has_group_desc_csum(sb) &&
2016 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2017 						      block_group, gdp)))
2018 		return 0;
2019 
2020 	return 1;
2021 }
2022 
2023 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2024 			      struct ext4_group_desc *gdp)
2025 {
2026 	if (!ext4_has_group_desc_csum(sb))
2027 		return;
2028 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2029 }
2030 
2031 /* Called at mount-time, super-block is locked */
2032 static int ext4_check_descriptors(struct super_block *sb,
2033 				  ext4_group_t *first_not_zeroed)
2034 {
2035 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2036 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2037 	ext4_fsblk_t last_block;
2038 	ext4_fsblk_t block_bitmap;
2039 	ext4_fsblk_t inode_bitmap;
2040 	ext4_fsblk_t inode_table;
2041 	int flexbg_flag = 0;
2042 	ext4_group_t i, grp = sbi->s_groups_count;
2043 
2044 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2045 		flexbg_flag = 1;
2046 
2047 	ext4_debug("Checking group descriptors");
2048 
2049 	for (i = 0; i < sbi->s_groups_count; i++) {
2050 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2051 
2052 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2053 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2054 		else
2055 			last_block = first_block +
2056 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2057 
2058 		if ((grp == sbi->s_groups_count) &&
2059 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2060 			grp = i;
2061 
2062 		block_bitmap = ext4_block_bitmap(sb, gdp);
2063 		if (block_bitmap < first_block || block_bitmap > last_block) {
2064 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2065 			       "Block bitmap for group %u not in group "
2066 			       "(block %llu)!", i, block_bitmap);
2067 			return 0;
2068 		}
2069 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2070 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2071 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2072 			       "Inode bitmap for group %u not in group "
2073 			       "(block %llu)!", i, inode_bitmap);
2074 			return 0;
2075 		}
2076 		inode_table = ext4_inode_table(sb, gdp);
2077 		if (inode_table < first_block ||
2078 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2079 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2080 			       "Inode table for group %u not in group "
2081 			       "(block %llu)!", i, inode_table);
2082 			return 0;
2083 		}
2084 		ext4_lock_group(sb, i);
2085 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2086 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2087 				 "Checksum for group %u failed (%u!=%u)",
2088 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2089 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2090 			if (!(sb->s_flags & MS_RDONLY)) {
2091 				ext4_unlock_group(sb, i);
2092 				return 0;
2093 			}
2094 		}
2095 		ext4_unlock_group(sb, i);
2096 		if (!flexbg_flag)
2097 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2098 	}
2099 	if (NULL != first_not_zeroed)
2100 		*first_not_zeroed = grp;
2101 
2102 	ext4_free_blocks_count_set(sbi->s_es,
2103 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2104 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2105 	return 1;
2106 }
2107 
2108 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2109  * the superblock) which were deleted from all directories, but held open by
2110  * a process at the time of a crash.  We walk the list and try to delete these
2111  * inodes at recovery time (only with a read-write filesystem).
2112  *
2113  * In order to keep the orphan inode chain consistent during traversal (in
2114  * case of crash during recovery), we link each inode into the superblock
2115  * orphan list_head and handle it the same way as an inode deletion during
2116  * normal operation (which journals the operations for us).
2117  *
2118  * We only do an iget() and an iput() on each inode, which is very safe if we
2119  * accidentally point at an in-use or already deleted inode.  The worst that
2120  * can happen in this case is that we get a "bit already cleared" message from
2121  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2122  * e2fsck was run on this filesystem, and it must have already done the orphan
2123  * inode cleanup for us, so we can safely abort without any further action.
2124  */
2125 static void ext4_orphan_cleanup(struct super_block *sb,
2126 				struct ext4_super_block *es)
2127 {
2128 	unsigned int s_flags = sb->s_flags;
2129 	int nr_orphans = 0, nr_truncates = 0;
2130 #ifdef CONFIG_QUOTA
2131 	int i;
2132 #endif
2133 	if (!es->s_last_orphan) {
2134 		jbd_debug(4, "no orphan inodes to clean up\n");
2135 		return;
2136 	}
2137 
2138 	if (bdev_read_only(sb->s_bdev)) {
2139 		ext4_msg(sb, KERN_ERR, "write access "
2140 			"unavailable, skipping orphan cleanup");
2141 		return;
2142 	}
2143 
2144 	/* Check if feature set would not allow a r/w mount */
2145 	if (!ext4_feature_set_ok(sb, 0)) {
2146 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2147 			 "unknown ROCOMPAT features");
2148 		return;
2149 	}
2150 
2151 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2152 		if (es->s_last_orphan)
2153 			jbd_debug(1, "Errors on filesystem, "
2154 				  "clearing orphan list.\n");
2155 		es->s_last_orphan = 0;
2156 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2157 		return;
2158 	}
2159 
2160 	if (s_flags & MS_RDONLY) {
2161 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2162 		sb->s_flags &= ~MS_RDONLY;
2163 	}
2164 #ifdef CONFIG_QUOTA
2165 	/* Needed for iput() to work correctly and not trash data */
2166 	sb->s_flags |= MS_ACTIVE;
2167 	/* Turn on quotas so that they are updated correctly */
2168 	for (i = 0; i < MAXQUOTAS; i++) {
2169 		if (EXT4_SB(sb)->s_qf_names[i]) {
2170 			int ret = ext4_quota_on_mount(sb, i);
2171 			if (ret < 0)
2172 				ext4_msg(sb, KERN_ERR,
2173 					"Cannot turn on journaled "
2174 					"quota: error %d", ret);
2175 		}
2176 	}
2177 #endif
2178 
2179 	while (es->s_last_orphan) {
2180 		struct inode *inode;
2181 
2182 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2183 		if (IS_ERR(inode)) {
2184 			es->s_last_orphan = 0;
2185 			break;
2186 		}
2187 
2188 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2189 		dquot_initialize(inode);
2190 		if (inode->i_nlink) {
2191 			ext4_msg(sb, KERN_DEBUG,
2192 				"%s: truncating inode %lu to %lld bytes",
2193 				__func__, inode->i_ino, inode->i_size);
2194 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2195 				  inode->i_ino, inode->i_size);
2196 			ext4_truncate(inode);
2197 			nr_truncates++;
2198 		} else {
2199 			ext4_msg(sb, KERN_DEBUG,
2200 				"%s: deleting unreferenced inode %lu",
2201 				__func__, inode->i_ino);
2202 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2203 				  inode->i_ino);
2204 			nr_orphans++;
2205 		}
2206 		iput(inode);  /* The delete magic happens here! */
2207 	}
2208 
2209 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2210 
2211 	if (nr_orphans)
2212 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2213 		       PLURAL(nr_orphans));
2214 	if (nr_truncates)
2215 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2216 		       PLURAL(nr_truncates));
2217 #ifdef CONFIG_QUOTA
2218 	/* Turn quotas off */
2219 	for (i = 0; i < MAXQUOTAS; i++) {
2220 		if (sb_dqopt(sb)->files[i])
2221 			dquot_quota_off(sb, i);
2222 	}
2223 #endif
2224 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2225 }
2226 
2227 /*
2228  * Maximal extent format file size.
2229  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2230  * extent format containers, within a sector_t, and within i_blocks
2231  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2232  * so that won't be a limiting factor.
2233  *
2234  * However there is other limiting factor. We do store extents in the form
2235  * of starting block and length, hence the resulting length of the extent
2236  * covering maximum file size must fit into on-disk format containers as
2237  * well. Given that length is always by 1 unit bigger than max unit (because
2238  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2239  *
2240  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2241  */
2242 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2243 {
2244 	loff_t res;
2245 	loff_t upper_limit = MAX_LFS_FILESIZE;
2246 
2247 	/* small i_blocks in vfs inode? */
2248 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2249 		/*
2250 		 * CONFIG_LBDAF is not enabled implies the inode
2251 		 * i_block represent total blocks in 512 bytes
2252 		 * 32 == size of vfs inode i_blocks * 8
2253 		 */
2254 		upper_limit = (1LL << 32) - 1;
2255 
2256 		/* total blocks in file system block size */
2257 		upper_limit >>= (blkbits - 9);
2258 		upper_limit <<= blkbits;
2259 	}
2260 
2261 	/*
2262 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2263 	 * by one fs block, so ee_len can cover the extent of maximum file
2264 	 * size
2265 	 */
2266 	res = (1LL << 32) - 1;
2267 	res <<= blkbits;
2268 
2269 	/* Sanity check against vm- & vfs- imposed limits */
2270 	if (res > upper_limit)
2271 		res = upper_limit;
2272 
2273 	return res;
2274 }
2275 
2276 /*
2277  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2278  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2279  * We need to be 1 filesystem block less than the 2^48 sector limit.
2280  */
2281 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2282 {
2283 	loff_t res = EXT4_NDIR_BLOCKS;
2284 	int meta_blocks;
2285 	loff_t upper_limit;
2286 	/* This is calculated to be the largest file size for a dense, block
2287 	 * mapped file such that the file's total number of 512-byte sectors,
2288 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2289 	 *
2290 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2291 	 * number of 512-byte sectors of the file.
2292 	 */
2293 
2294 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2295 		/*
2296 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2297 		 * the inode i_block field represents total file blocks in
2298 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2299 		 */
2300 		upper_limit = (1LL << 32) - 1;
2301 
2302 		/* total blocks in file system block size */
2303 		upper_limit >>= (bits - 9);
2304 
2305 	} else {
2306 		/*
2307 		 * We use 48 bit ext4_inode i_blocks
2308 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2309 		 * represent total number of blocks in
2310 		 * file system block size
2311 		 */
2312 		upper_limit = (1LL << 48) - 1;
2313 
2314 	}
2315 
2316 	/* indirect blocks */
2317 	meta_blocks = 1;
2318 	/* double indirect blocks */
2319 	meta_blocks += 1 + (1LL << (bits-2));
2320 	/* tripple indirect blocks */
2321 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2322 
2323 	upper_limit -= meta_blocks;
2324 	upper_limit <<= bits;
2325 
2326 	res += 1LL << (bits-2);
2327 	res += 1LL << (2*(bits-2));
2328 	res += 1LL << (3*(bits-2));
2329 	res <<= bits;
2330 	if (res > upper_limit)
2331 		res = upper_limit;
2332 
2333 	if (res > MAX_LFS_FILESIZE)
2334 		res = MAX_LFS_FILESIZE;
2335 
2336 	return res;
2337 }
2338 
2339 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2340 				   ext4_fsblk_t logical_sb_block, int nr)
2341 {
2342 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2343 	ext4_group_t bg, first_meta_bg;
2344 	int has_super = 0;
2345 
2346 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2347 
2348 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2349 	    nr < first_meta_bg)
2350 		return logical_sb_block + nr + 1;
2351 	bg = sbi->s_desc_per_block * nr;
2352 	if (ext4_bg_has_super(sb, bg))
2353 		has_super = 1;
2354 
2355 	return (has_super + ext4_group_first_block_no(sb, bg));
2356 }
2357 
2358 /**
2359  * ext4_get_stripe_size: Get the stripe size.
2360  * @sbi: In memory super block info
2361  *
2362  * If we have specified it via mount option, then
2363  * use the mount option value. If the value specified at mount time is
2364  * greater than the blocks per group use the super block value.
2365  * If the super block value is greater than blocks per group return 0.
2366  * Allocator needs it be less than blocks per group.
2367  *
2368  */
2369 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2370 {
2371 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2372 	unsigned long stripe_width =
2373 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2374 	int ret;
2375 
2376 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2377 		ret = sbi->s_stripe;
2378 	else if (stripe_width <= sbi->s_blocks_per_group)
2379 		ret = stripe_width;
2380 	else if (stride <= sbi->s_blocks_per_group)
2381 		ret = stride;
2382 	else
2383 		ret = 0;
2384 
2385 	/*
2386 	 * If the stripe width is 1, this makes no sense and
2387 	 * we set it to 0 to turn off stripe handling code.
2388 	 */
2389 	if (ret <= 1)
2390 		ret = 0;
2391 
2392 	return ret;
2393 }
2394 
2395 /* sysfs supprt */
2396 
2397 struct ext4_attr {
2398 	struct attribute attr;
2399 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2400 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2401 			 const char *, size_t);
2402 	int offset;
2403 };
2404 
2405 static int parse_strtoul(const char *buf,
2406 		unsigned long max, unsigned long *value)
2407 {
2408 	char *endp;
2409 
2410 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2411 	endp = skip_spaces(endp);
2412 	if (*endp || *value > max)
2413 		return -EINVAL;
2414 
2415 	return 0;
2416 }
2417 
2418 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2419 					      struct ext4_sb_info *sbi,
2420 					      char *buf)
2421 {
2422 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2423 		(s64) EXT4_C2B(sbi,
2424 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2425 }
2426 
2427 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2428 					 struct ext4_sb_info *sbi, char *buf)
2429 {
2430 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2431 
2432 	if (!sb->s_bdev->bd_part)
2433 		return snprintf(buf, PAGE_SIZE, "0\n");
2434 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2435 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2436 			 sbi->s_sectors_written_start) >> 1);
2437 }
2438 
2439 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2440 					  struct ext4_sb_info *sbi, char *buf)
2441 {
2442 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2443 
2444 	if (!sb->s_bdev->bd_part)
2445 		return snprintf(buf, PAGE_SIZE, "0\n");
2446 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2447 			(unsigned long long)(sbi->s_kbytes_written +
2448 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2449 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2450 }
2451 
2452 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2453 					  struct ext4_sb_info *sbi,
2454 					  const char *buf, size_t count)
2455 {
2456 	unsigned long t;
2457 
2458 	if (parse_strtoul(buf, 0x40000000, &t))
2459 		return -EINVAL;
2460 
2461 	if (t && !is_power_of_2(t))
2462 		return -EINVAL;
2463 
2464 	sbi->s_inode_readahead_blks = t;
2465 	return count;
2466 }
2467 
2468 static ssize_t sbi_ui_show(struct ext4_attr *a,
2469 			   struct ext4_sb_info *sbi, char *buf)
2470 {
2471 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2472 
2473 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2474 }
2475 
2476 static ssize_t sbi_ui_store(struct ext4_attr *a,
2477 			    struct ext4_sb_info *sbi,
2478 			    const char *buf, size_t count)
2479 {
2480 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2481 	unsigned long t;
2482 
2483 	if (parse_strtoul(buf, 0xffffffff, &t))
2484 		return -EINVAL;
2485 	*ui = t;
2486 	return count;
2487 }
2488 
2489 static ssize_t trigger_test_error(struct ext4_attr *a,
2490 				  struct ext4_sb_info *sbi,
2491 				  const char *buf, size_t count)
2492 {
2493 	int len = count;
2494 
2495 	if (!capable(CAP_SYS_ADMIN))
2496 		return -EPERM;
2497 
2498 	if (len && buf[len-1] == '\n')
2499 		len--;
2500 
2501 	if (len)
2502 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2503 	return count;
2504 }
2505 
2506 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2507 static struct ext4_attr ext4_attr_##_name = {			\
2508 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2509 	.show	= _show,					\
2510 	.store	= _store,					\
2511 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2512 }
2513 #define EXT4_ATTR(name, mode, show, store) \
2514 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2515 
2516 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2517 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2518 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2519 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2520 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2521 #define ATTR_LIST(name) &ext4_attr_##name.attr
2522 
2523 EXT4_RO_ATTR(delayed_allocation_blocks);
2524 EXT4_RO_ATTR(session_write_kbytes);
2525 EXT4_RO_ATTR(lifetime_write_kbytes);
2526 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2527 		 inode_readahead_blks_store, s_inode_readahead_blks);
2528 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2529 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2530 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2531 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2532 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2533 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2534 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2535 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2536 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2537 
2538 static struct attribute *ext4_attrs[] = {
2539 	ATTR_LIST(delayed_allocation_blocks),
2540 	ATTR_LIST(session_write_kbytes),
2541 	ATTR_LIST(lifetime_write_kbytes),
2542 	ATTR_LIST(inode_readahead_blks),
2543 	ATTR_LIST(inode_goal),
2544 	ATTR_LIST(mb_stats),
2545 	ATTR_LIST(mb_max_to_scan),
2546 	ATTR_LIST(mb_min_to_scan),
2547 	ATTR_LIST(mb_order2_req),
2548 	ATTR_LIST(mb_stream_req),
2549 	ATTR_LIST(mb_group_prealloc),
2550 	ATTR_LIST(max_writeback_mb_bump),
2551 	ATTR_LIST(trigger_fs_error),
2552 	NULL,
2553 };
2554 
2555 /* Features this copy of ext4 supports */
2556 EXT4_INFO_ATTR(lazy_itable_init);
2557 EXT4_INFO_ATTR(batched_discard);
2558 
2559 static struct attribute *ext4_feat_attrs[] = {
2560 	ATTR_LIST(lazy_itable_init),
2561 	ATTR_LIST(batched_discard),
2562 	NULL,
2563 };
2564 
2565 static ssize_t ext4_attr_show(struct kobject *kobj,
2566 			      struct attribute *attr, char *buf)
2567 {
2568 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2569 						s_kobj);
2570 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2571 
2572 	return a->show ? a->show(a, sbi, buf) : 0;
2573 }
2574 
2575 static ssize_t ext4_attr_store(struct kobject *kobj,
2576 			       struct attribute *attr,
2577 			       const char *buf, size_t len)
2578 {
2579 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2580 						s_kobj);
2581 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2582 
2583 	return a->store ? a->store(a, sbi, buf, len) : 0;
2584 }
2585 
2586 static void ext4_sb_release(struct kobject *kobj)
2587 {
2588 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2589 						s_kobj);
2590 	complete(&sbi->s_kobj_unregister);
2591 }
2592 
2593 static const struct sysfs_ops ext4_attr_ops = {
2594 	.show	= ext4_attr_show,
2595 	.store	= ext4_attr_store,
2596 };
2597 
2598 static struct kobj_type ext4_ktype = {
2599 	.default_attrs	= ext4_attrs,
2600 	.sysfs_ops	= &ext4_attr_ops,
2601 	.release	= ext4_sb_release,
2602 };
2603 
2604 static void ext4_feat_release(struct kobject *kobj)
2605 {
2606 	complete(&ext4_feat->f_kobj_unregister);
2607 }
2608 
2609 static struct kobj_type ext4_feat_ktype = {
2610 	.default_attrs	= ext4_feat_attrs,
2611 	.sysfs_ops	= &ext4_attr_ops,
2612 	.release	= ext4_feat_release,
2613 };
2614 
2615 /*
2616  * Check whether this filesystem can be mounted based on
2617  * the features present and the RDONLY/RDWR mount requested.
2618  * Returns 1 if this filesystem can be mounted as requested,
2619  * 0 if it cannot be.
2620  */
2621 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2622 {
2623 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2624 		ext4_msg(sb, KERN_ERR,
2625 			"Couldn't mount because of "
2626 			"unsupported optional features (%x)",
2627 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2628 			~EXT4_FEATURE_INCOMPAT_SUPP));
2629 		return 0;
2630 	}
2631 
2632 	if (readonly)
2633 		return 1;
2634 
2635 	/* Check that feature set is OK for a read-write mount */
2636 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2637 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2638 			 "unsupported optional features (%x)",
2639 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2640 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2641 		return 0;
2642 	}
2643 	/*
2644 	 * Large file size enabled file system can only be mounted
2645 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2646 	 */
2647 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2648 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2649 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2650 				 "cannot be mounted RDWR without "
2651 				 "CONFIG_LBDAF");
2652 			return 0;
2653 		}
2654 	}
2655 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2656 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2657 		ext4_msg(sb, KERN_ERR,
2658 			 "Can't support bigalloc feature without "
2659 			 "extents feature\n");
2660 		return 0;
2661 	}
2662 
2663 #ifndef CONFIG_QUOTA
2664 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2665 	    !readonly) {
2666 		ext4_msg(sb, KERN_ERR,
2667 			 "Filesystem with quota feature cannot be mounted RDWR "
2668 			 "without CONFIG_QUOTA");
2669 		return 0;
2670 	}
2671 #endif  /* CONFIG_QUOTA */
2672 	return 1;
2673 }
2674 
2675 /*
2676  * This function is called once a day if we have errors logged
2677  * on the file system
2678  */
2679 static void print_daily_error_info(unsigned long arg)
2680 {
2681 	struct super_block *sb = (struct super_block *) arg;
2682 	struct ext4_sb_info *sbi;
2683 	struct ext4_super_block *es;
2684 
2685 	sbi = EXT4_SB(sb);
2686 	es = sbi->s_es;
2687 
2688 	if (es->s_error_count)
2689 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2690 			 le32_to_cpu(es->s_error_count));
2691 	if (es->s_first_error_time) {
2692 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2693 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2694 		       (int) sizeof(es->s_first_error_func),
2695 		       es->s_first_error_func,
2696 		       le32_to_cpu(es->s_first_error_line));
2697 		if (es->s_first_error_ino)
2698 			printk(": inode %u",
2699 			       le32_to_cpu(es->s_first_error_ino));
2700 		if (es->s_first_error_block)
2701 			printk(": block %llu", (unsigned long long)
2702 			       le64_to_cpu(es->s_first_error_block));
2703 		printk("\n");
2704 	}
2705 	if (es->s_last_error_time) {
2706 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2707 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2708 		       (int) sizeof(es->s_last_error_func),
2709 		       es->s_last_error_func,
2710 		       le32_to_cpu(es->s_last_error_line));
2711 		if (es->s_last_error_ino)
2712 			printk(": inode %u",
2713 			       le32_to_cpu(es->s_last_error_ino));
2714 		if (es->s_last_error_block)
2715 			printk(": block %llu", (unsigned long long)
2716 			       le64_to_cpu(es->s_last_error_block));
2717 		printk("\n");
2718 	}
2719 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2720 }
2721 
2722 /* Find next suitable group and run ext4_init_inode_table */
2723 static int ext4_run_li_request(struct ext4_li_request *elr)
2724 {
2725 	struct ext4_group_desc *gdp = NULL;
2726 	ext4_group_t group, ngroups;
2727 	struct super_block *sb;
2728 	unsigned long timeout = 0;
2729 	int ret = 0;
2730 
2731 	sb = elr->lr_super;
2732 	ngroups = EXT4_SB(sb)->s_groups_count;
2733 
2734 	sb_start_write(sb);
2735 	for (group = elr->lr_next_group; group < ngroups; group++) {
2736 		gdp = ext4_get_group_desc(sb, group, NULL);
2737 		if (!gdp) {
2738 			ret = 1;
2739 			break;
2740 		}
2741 
2742 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2743 			break;
2744 	}
2745 
2746 	if (group == ngroups)
2747 		ret = 1;
2748 
2749 	if (!ret) {
2750 		timeout = jiffies;
2751 		ret = ext4_init_inode_table(sb, group,
2752 					    elr->lr_timeout ? 0 : 1);
2753 		if (elr->lr_timeout == 0) {
2754 			timeout = (jiffies - timeout) *
2755 				  elr->lr_sbi->s_li_wait_mult;
2756 			elr->lr_timeout = timeout;
2757 		}
2758 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2759 		elr->lr_next_group = group + 1;
2760 	}
2761 	sb_end_write(sb);
2762 
2763 	return ret;
2764 }
2765 
2766 /*
2767  * Remove lr_request from the list_request and free the
2768  * request structure. Should be called with li_list_mtx held
2769  */
2770 static void ext4_remove_li_request(struct ext4_li_request *elr)
2771 {
2772 	struct ext4_sb_info *sbi;
2773 
2774 	if (!elr)
2775 		return;
2776 
2777 	sbi = elr->lr_sbi;
2778 
2779 	list_del(&elr->lr_request);
2780 	sbi->s_li_request = NULL;
2781 	kfree(elr);
2782 }
2783 
2784 static void ext4_unregister_li_request(struct super_block *sb)
2785 {
2786 	mutex_lock(&ext4_li_mtx);
2787 	if (!ext4_li_info) {
2788 		mutex_unlock(&ext4_li_mtx);
2789 		return;
2790 	}
2791 
2792 	mutex_lock(&ext4_li_info->li_list_mtx);
2793 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2794 	mutex_unlock(&ext4_li_info->li_list_mtx);
2795 	mutex_unlock(&ext4_li_mtx);
2796 }
2797 
2798 static struct task_struct *ext4_lazyinit_task;
2799 
2800 /*
2801  * This is the function where ext4lazyinit thread lives. It walks
2802  * through the request list searching for next scheduled filesystem.
2803  * When such a fs is found, run the lazy initialization request
2804  * (ext4_rn_li_request) and keep track of the time spend in this
2805  * function. Based on that time we compute next schedule time of
2806  * the request. When walking through the list is complete, compute
2807  * next waking time and put itself into sleep.
2808  */
2809 static int ext4_lazyinit_thread(void *arg)
2810 {
2811 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2812 	struct list_head *pos, *n;
2813 	struct ext4_li_request *elr;
2814 	unsigned long next_wakeup, cur;
2815 
2816 	BUG_ON(NULL == eli);
2817 
2818 cont_thread:
2819 	while (true) {
2820 		next_wakeup = MAX_JIFFY_OFFSET;
2821 
2822 		mutex_lock(&eli->li_list_mtx);
2823 		if (list_empty(&eli->li_request_list)) {
2824 			mutex_unlock(&eli->li_list_mtx);
2825 			goto exit_thread;
2826 		}
2827 
2828 		list_for_each_safe(pos, n, &eli->li_request_list) {
2829 			elr = list_entry(pos, struct ext4_li_request,
2830 					 lr_request);
2831 
2832 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2833 				if (ext4_run_li_request(elr) != 0) {
2834 					/* error, remove the lazy_init job */
2835 					ext4_remove_li_request(elr);
2836 					continue;
2837 				}
2838 			}
2839 
2840 			if (time_before(elr->lr_next_sched, next_wakeup))
2841 				next_wakeup = elr->lr_next_sched;
2842 		}
2843 		mutex_unlock(&eli->li_list_mtx);
2844 
2845 		try_to_freeze();
2846 
2847 		cur = jiffies;
2848 		if ((time_after_eq(cur, next_wakeup)) ||
2849 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2850 			cond_resched();
2851 			continue;
2852 		}
2853 
2854 		schedule_timeout_interruptible(next_wakeup - cur);
2855 
2856 		if (kthread_should_stop()) {
2857 			ext4_clear_request_list();
2858 			goto exit_thread;
2859 		}
2860 	}
2861 
2862 exit_thread:
2863 	/*
2864 	 * It looks like the request list is empty, but we need
2865 	 * to check it under the li_list_mtx lock, to prevent any
2866 	 * additions into it, and of course we should lock ext4_li_mtx
2867 	 * to atomically free the list and ext4_li_info, because at
2868 	 * this point another ext4 filesystem could be registering
2869 	 * new one.
2870 	 */
2871 	mutex_lock(&ext4_li_mtx);
2872 	mutex_lock(&eli->li_list_mtx);
2873 	if (!list_empty(&eli->li_request_list)) {
2874 		mutex_unlock(&eli->li_list_mtx);
2875 		mutex_unlock(&ext4_li_mtx);
2876 		goto cont_thread;
2877 	}
2878 	mutex_unlock(&eli->li_list_mtx);
2879 	kfree(ext4_li_info);
2880 	ext4_li_info = NULL;
2881 	mutex_unlock(&ext4_li_mtx);
2882 
2883 	return 0;
2884 }
2885 
2886 static void ext4_clear_request_list(void)
2887 {
2888 	struct list_head *pos, *n;
2889 	struct ext4_li_request *elr;
2890 
2891 	mutex_lock(&ext4_li_info->li_list_mtx);
2892 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2893 		elr = list_entry(pos, struct ext4_li_request,
2894 				 lr_request);
2895 		ext4_remove_li_request(elr);
2896 	}
2897 	mutex_unlock(&ext4_li_info->li_list_mtx);
2898 }
2899 
2900 static int ext4_run_lazyinit_thread(void)
2901 {
2902 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2903 					 ext4_li_info, "ext4lazyinit");
2904 	if (IS_ERR(ext4_lazyinit_task)) {
2905 		int err = PTR_ERR(ext4_lazyinit_task);
2906 		ext4_clear_request_list();
2907 		kfree(ext4_li_info);
2908 		ext4_li_info = NULL;
2909 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2910 				 "initialization thread\n",
2911 				 err);
2912 		return err;
2913 	}
2914 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2915 	return 0;
2916 }
2917 
2918 /*
2919  * Check whether it make sense to run itable init. thread or not.
2920  * If there is at least one uninitialized inode table, return
2921  * corresponding group number, else the loop goes through all
2922  * groups and return total number of groups.
2923  */
2924 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2925 {
2926 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2927 	struct ext4_group_desc *gdp = NULL;
2928 
2929 	for (group = 0; group < ngroups; group++) {
2930 		gdp = ext4_get_group_desc(sb, group, NULL);
2931 		if (!gdp)
2932 			continue;
2933 
2934 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2935 			break;
2936 	}
2937 
2938 	return group;
2939 }
2940 
2941 static int ext4_li_info_new(void)
2942 {
2943 	struct ext4_lazy_init *eli = NULL;
2944 
2945 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2946 	if (!eli)
2947 		return -ENOMEM;
2948 
2949 	INIT_LIST_HEAD(&eli->li_request_list);
2950 	mutex_init(&eli->li_list_mtx);
2951 
2952 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2953 
2954 	ext4_li_info = eli;
2955 
2956 	return 0;
2957 }
2958 
2959 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2960 					    ext4_group_t start)
2961 {
2962 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2963 	struct ext4_li_request *elr;
2964 	unsigned long rnd;
2965 
2966 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2967 	if (!elr)
2968 		return NULL;
2969 
2970 	elr->lr_super = sb;
2971 	elr->lr_sbi = sbi;
2972 	elr->lr_next_group = start;
2973 
2974 	/*
2975 	 * Randomize first schedule time of the request to
2976 	 * spread the inode table initialization requests
2977 	 * better.
2978 	 */
2979 	get_random_bytes(&rnd, sizeof(rnd));
2980 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
2981 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2982 
2983 	return elr;
2984 }
2985 
2986 static int ext4_register_li_request(struct super_block *sb,
2987 				    ext4_group_t first_not_zeroed)
2988 {
2989 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2990 	struct ext4_li_request *elr;
2991 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2992 	int ret = 0;
2993 
2994 	if (sbi->s_li_request != NULL) {
2995 		/*
2996 		 * Reset timeout so it can be computed again, because
2997 		 * s_li_wait_mult might have changed.
2998 		 */
2999 		sbi->s_li_request->lr_timeout = 0;
3000 		return 0;
3001 	}
3002 
3003 	if (first_not_zeroed == ngroups ||
3004 	    (sb->s_flags & MS_RDONLY) ||
3005 	    !test_opt(sb, INIT_INODE_TABLE))
3006 		return 0;
3007 
3008 	elr = ext4_li_request_new(sb, first_not_zeroed);
3009 	if (!elr)
3010 		return -ENOMEM;
3011 
3012 	mutex_lock(&ext4_li_mtx);
3013 
3014 	if (NULL == ext4_li_info) {
3015 		ret = ext4_li_info_new();
3016 		if (ret)
3017 			goto out;
3018 	}
3019 
3020 	mutex_lock(&ext4_li_info->li_list_mtx);
3021 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3022 	mutex_unlock(&ext4_li_info->li_list_mtx);
3023 
3024 	sbi->s_li_request = elr;
3025 	/*
3026 	 * set elr to NULL here since it has been inserted to
3027 	 * the request_list and the removal and free of it is
3028 	 * handled by ext4_clear_request_list from now on.
3029 	 */
3030 	elr = NULL;
3031 
3032 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3033 		ret = ext4_run_lazyinit_thread();
3034 		if (ret)
3035 			goto out;
3036 	}
3037 out:
3038 	mutex_unlock(&ext4_li_mtx);
3039 	if (ret)
3040 		kfree(elr);
3041 	return ret;
3042 }
3043 
3044 /*
3045  * We do not need to lock anything since this is called on
3046  * module unload.
3047  */
3048 static void ext4_destroy_lazyinit_thread(void)
3049 {
3050 	/*
3051 	 * If thread exited earlier
3052 	 * there's nothing to be done.
3053 	 */
3054 	if (!ext4_li_info || !ext4_lazyinit_task)
3055 		return;
3056 
3057 	kthread_stop(ext4_lazyinit_task);
3058 }
3059 
3060 static int set_journal_csum_feature_set(struct super_block *sb)
3061 {
3062 	int ret = 1;
3063 	int compat, incompat;
3064 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3065 
3066 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3067 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3068 		/* journal checksum v2 */
3069 		compat = 0;
3070 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3071 	} else {
3072 		/* journal checksum v1 */
3073 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3074 		incompat = 0;
3075 	}
3076 
3077 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3078 		ret = jbd2_journal_set_features(sbi->s_journal,
3079 				compat, 0,
3080 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3081 				incompat);
3082 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3083 		ret = jbd2_journal_set_features(sbi->s_journal,
3084 				compat, 0,
3085 				incompat);
3086 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3087 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3088 	} else {
3089 		jbd2_journal_clear_features(sbi->s_journal,
3090 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3091 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3092 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3093 	}
3094 
3095 	return ret;
3096 }
3097 
3098 /*
3099  * Note: calculating the overhead so we can be compatible with
3100  * historical BSD practice is quite difficult in the face of
3101  * clusters/bigalloc.  This is because multiple metadata blocks from
3102  * different block group can end up in the same allocation cluster.
3103  * Calculating the exact overhead in the face of clustered allocation
3104  * requires either O(all block bitmaps) in memory or O(number of block
3105  * groups**2) in time.  We will still calculate the superblock for
3106  * older file systems --- and if we come across with a bigalloc file
3107  * system with zero in s_overhead_clusters the estimate will be close to
3108  * correct especially for very large cluster sizes --- but for newer
3109  * file systems, it's better to calculate this figure once at mkfs
3110  * time, and store it in the superblock.  If the superblock value is
3111  * present (even for non-bigalloc file systems), we will use it.
3112  */
3113 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3114 			  char *buf)
3115 {
3116 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3117 	struct ext4_group_desc	*gdp;
3118 	ext4_fsblk_t		first_block, last_block, b;
3119 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3120 	int			s, j, count = 0;
3121 
3122 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3123 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3124 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3125 	for (i = 0; i < ngroups; i++) {
3126 		gdp = ext4_get_group_desc(sb, i, NULL);
3127 		b = ext4_block_bitmap(sb, gdp);
3128 		if (b >= first_block && b <= last_block) {
3129 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3130 			count++;
3131 		}
3132 		b = ext4_inode_bitmap(sb, gdp);
3133 		if (b >= first_block && b <= last_block) {
3134 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3135 			count++;
3136 		}
3137 		b = ext4_inode_table(sb, gdp);
3138 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3139 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3140 				int c = EXT4_B2C(sbi, b - first_block);
3141 				ext4_set_bit(c, buf);
3142 				count++;
3143 			}
3144 		if (i != grp)
3145 			continue;
3146 		s = 0;
3147 		if (ext4_bg_has_super(sb, grp)) {
3148 			ext4_set_bit(s++, buf);
3149 			count++;
3150 		}
3151 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3152 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3153 			count++;
3154 		}
3155 	}
3156 	if (!count)
3157 		return 0;
3158 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3159 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3160 }
3161 
3162 /*
3163  * Compute the overhead and stash it in sbi->s_overhead
3164  */
3165 int ext4_calculate_overhead(struct super_block *sb)
3166 {
3167 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3168 	struct ext4_super_block *es = sbi->s_es;
3169 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3170 	ext4_fsblk_t overhead = 0;
3171 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3172 
3173 	memset(buf, 0, PAGE_SIZE);
3174 	if (!buf)
3175 		return -ENOMEM;
3176 
3177 	/*
3178 	 * Compute the overhead (FS structures).  This is constant
3179 	 * for a given filesystem unless the number of block groups
3180 	 * changes so we cache the previous value until it does.
3181 	 */
3182 
3183 	/*
3184 	 * All of the blocks before first_data_block are overhead
3185 	 */
3186 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3187 
3188 	/*
3189 	 * Add the overhead found in each block group
3190 	 */
3191 	for (i = 0; i < ngroups; i++) {
3192 		int blks;
3193 
3194 		blks = count_overhead(sb, i, buf);
3195 		overhead += blks;
3196 		if (blks)
3197 			memset(buf, 0, PAGE_SIZE);
3198 		cond_resched();
3199 	}
3200 	sbi->s_overhead = overhead;
3201 	smp_wmb();
3202 	free_page((unsigned long) buf);
3203 	return 0;
3204 }
3205 
3206 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3207 {
3208 	char *orig_data = kstrdup(data, GFP_KERNEL);
3209 	struct buffer_head *bh;
3210 	struct ext4_super_block *es = NULL;
3211 	struct ext4_sb_info *sbi;
3212 	ext4_fsblk_t block;
3213 	ext4_fsblk_t sb_block = get_sb_block(&data);
3214 	ext4_fsblk_t logical_sb_block;
3215 	unsigned long offset = 0;
3216 	unsigned long journal_devnum = 0;
3217 	unsigned long def_mount_opts;
3218 	struct inode *root;
3219 	char *cp;
3220 	const char *descr;
3221 	int ret = -ENOMEM;
3222 	int blocksize, clustersize;
3223 	unsigned int db_count;
3224 	unsigned int i;
3225 	int needs_recovery, has_huge_files, has_bigalloc;
3226 	__u64 blocks_count;
3227 	int err;
3228 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3229 	ext4_group_t first_not_zeroed;
3230 
3231 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3232 	if (!sbi)
3233 		goto out_free_orig;
3234 
3235 	sbi->s_blockgroup_lock =
3236 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3237 	if (!sbi->s_blockgroup_lock) {
3238 		kfree(sbi);
3239 		goto out_free_orig;
3240 	}
3241 	sb->s_fs_info = sbi;
3242 	sbi->s_sb = sb;
3243 	sbi->s_mount_opt = 0;
3244 	sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
3245 	sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
3246 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3247 	sbi->s_sb_block = sb_block;
3248 	if (sb->s_bdev->bd_part)
3249 		sbi->s_sectors_written_start =
3250 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3251 
3252 	/* Cleanup superblock name */
3253 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3254 		*cp = '!';
3255 
3256 	ret = -EINVAL;
3257 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3258 	if (!blocksize) {
3259 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3260 		goto out_fail;
3261 	}
3262 
3263 	/*
3264 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3265 	 * block sizes.  We need to calculate the offset from buffer start.
3266 	 */
3267 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3268 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3269 		offset = do_div(logical_sb_block, blocksize);
3270 	} else {
3271 		logical_sb_block = sb_block;
3272 	}
3273 
3274 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3275 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3276 		goto out_fail;
3277 	}
3278 	/*
3279 	 * Note: s_es must be initialized as soon as possible because
3280 	 *       some ext4 macro-instructions depend on its value
3281 	 */
3282 	es = (struct ext4_super_block *) (bh->b_data + offset);
3283 	sbi->s_es = es;
3284 	sb->s_magic = le16_to_cpu(es->s_magic);
3285 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3286 		goto cantfind_ext4;
3287 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3288 
3289 	/* Warn if metadata_csum and gdt_csum are both set. */
3290 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3291 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3292 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3293 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3294 			     "redundant flags; please run fsck.");
3295 
3296 	/* Check for a known checksum algorithm */
3297 	if (!ext4_verify_csum_type(sb, es)) {
3298 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3299 			 "unknown checksum algorithm.");
3300 		silent = 1;
3301 		goto cantfind_ext4;
3302 	}
3303 
3304 	/* Load the checksum driver */
3305 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3306 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3307 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3308 		if (IS_ERR(sbi->s_chksum_driver)) {
3309 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3310 			ret = PTR_ERR(sbi->s_chksum_driver);
3311 			sbi->s_chksum_driver = NULL;
3312 			goto failed_mount;
3313 		}
3314 	}
3315 
3316 	/* Check superblock checksum */
3317 	if (!ext4_superblock_csum_verify(sb, es)) {
3318 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3319 			 "invalid superblock checksum.  Run e2fsck?");
3320 		silent = 1;
3321 		goto cantfind_ext4;
3322 	}
3323 
3324 	/* Precompute checksum seed for all metadata */
3325 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3326 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3327 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3328 					       sizeof(es->s_uuid));
3329 
3330 	/* Set defaults before we parse the mount options */
3331 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3332 	set_opt(sb, INIT_INODE_TABLE);
3333 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3334 		set_opt(sb, DEBUG);
3335 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3336 		set_opt(sb, GRPID);
3337 	if (def_mount_opts & EXT4_DEFM_UID16)
3338 		set_opt(sb, NO_UID32);
3339 	/* xattr user namespace & acls are now defaulted on */
3340 #ifdef CONFIG_EXT4_FS_XATTR
3341 	set_opt(sb, XATTR_USER);
3342 #endif
3343 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3344 	set_opt(sb, POSIX_ACL);
3345 #endif
3346 	set_opt(sb, MBLK_IO_SUBMIT);
3347 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3348 		set_opt(sb, JOURNAL_DATA);
3349 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3350 		set_opt(sb, ORDERED_DATA);
3351 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3352 		set_opt(sb, WRITEBACK_DATA);
3353 
3354 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3355 		set_opt(sb, ERRORS_PANIC);
3356 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3357 		set_opt(sb, ERRORS_CONT);
3358 	else
3359 		set_opt(sb, ERRORS_RO);
3360 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3361 		set_opt(sb, BLOCK_VALIDITY);
3362 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3363 		set_opt(sb, DISCARD);
3364 
3365 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3366 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3367 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3368 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3369 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3370 
3371 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3372 		set_opt(sb, BARRIER);
3373 
3374 	/*
3375 	 * enable delayed allocation by default
3376 	 * Use -o nodelalloc to turn it off
3377 	 */
3378 	if (!IS_EXT3_SB(sb) &&
3379 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3380 		set_opt(sb, DELALLOC);
3381 
3382 	/*
3383 	 * set default s_li_wait_mult for lazyinit, for the case there is
3384 	 * no mount option specified.
3385 	 */
3386 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3387 
3388 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3389 			   &journal_devnum, &journal_ioprio, 0)) {
3390 		ext4_msg(sb, KERN_WARNING,
3391 			 "failed to parse options in superblock: %s",
3392 			 sbi->s_es->s_mount_opts);
3393 	}
3394 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3395 	if (!parse_options((char *) data, sb, &journal_devnum,
3396 			   &journal_ioprio, 0))
3397 		goto failed_mount;
3398 
3399 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3400 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3401 			    "with data=journal disables delayed "
3402 			    "allocation and O_DIRECT support!\n");
3403 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3404 			ext4_msg(sb, KERN_ERR, "can't mount with "
3405 				 "both data=journal and delalloc");
3406 			goto failed_mount;
3407 		}
3408 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3409 			ext4_msg(sb, KERN_ERR, "can't mount with "
3410 				 "both data=journal and delalloc");
3411 			goto failed_mount;
3412 		}
3413 		if (test_opt(sb, DELALLOC))
3414 			clear_opt(sb, DELALLOC);
3415 	}
3416 
3417 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3418 	if (test_opt(sb, DIOREAD_NOLOCK)) {
3419 		if (blocksize < PAGE_SIZE) {
3420 			ext4_msg(sb, KERN_ERR, "can't mount with "
3421 				 "dioread_nolock if block size != PAGE_SIZE");
3422 			goto failed_mount;
3423 		}
3424 	}
3425 
3426 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3427 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3428 
3429 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3430 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3431 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3432 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3433 		ext4_msg(sb, KERN_WARNING,
3434 		       "feature flags set on rev 0 fs, "
3435 		       "running e2fsck is recommended");
3436 
3437 	if (IS_EXT2_SB(sb)) {
3438 		if (ext2_feature_set_ok(sb))
3439 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3440 				 "using the ext4 subsystem");
3441 		else {
3442 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3443 				 "to feature incompatibilities");
3444 			goto failed_mount;
3445 		}
3446 	}
3447 
3448 	if (IS_EXT3_SB(sb)) {
3449 		if (ext3_feature_set_ok(sb))
3450 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3451 				 "using the ext4 subsystem");
3452 		else {
3453 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3454 				 "to feature incompatibilities");
3455 			goto failed_mount;
3456 		}
3457 	}
3458 
3459 	/*
3460 	 * Check feature flags regardless of the revision level, since we
3461 	 * previously didn't change the revision level when setting the flags,
3462 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3463 	 */
3464 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3465 		goto failed_mount;
3466 
3467 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3468 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3469 		ext4_msg(sb, KERN_ERR,
3470 		       "Unsupported filesystem blocksize %d", blocksize);
3471 		goto failed_mount;
3472 	}
3473 
3474 	if (sb->s_blocksize != blocksize) {
3475 		/* Validate the filesystem blocksize */
3476 		if (!sb_set_blocksize(sb, blocksize)) {
3477 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3478 					blocksize);
3479 			goto failed_mount;
3480 		}
3481 
3482 		brelse(bh);
3483 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3484 		offset = do_div(logical_sb_block, blocksize);
3485 		bh = sb_bread(sb, logical_sb_block);
3486 		if (!bh) {
3487 			ext4_msg(sb, KERN_ERR,
3488 			       "Can't read superblock on 2nd try");
3489 			goto failed_mount;
3490 		}
3491 		es = (struct ext4_super_block *)(bh->b_data + offset);
3492 		sbi->s_es = es;
3493 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3494 			ext4_msg(sb, KERN_ERR,
3495 			       "Magic mismatch, very weird!");
3496 			goto failed_mount;
3497 		}
3498 	}
3499 
3500 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3501 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3502 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3503 						      has_huge_files);
3504 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3505 
3506 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3507 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3508 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3509 	} else {
3510 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3511 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3512 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3513 		    (!is_power_of_2(sbi->s_inode_size)) ||
3514 		    (sbi->s_inode_size > blocksize)) {
3515 			ext4_msg(sb, KERN_ERR,
3516 			       "unsupported inode size: %d",
3517 			       sbi->s_inode_size);
3518 			goto failed_mount;
3519 		}
3520 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3521 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3522 	}
3523 
3524 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3525 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3526 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3527 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3528 		    !is_power_of_2(sbi->s_desc_size)) {
3529 			ext4_msg(sb, KERN_ERR,
3530 			       "unsupported descriptor size %lu",
3531 			       sbi->s_desc_size);
3532 			goto failed_mount;
3533 		}
3534 	} else
3535 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3536 
3537 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3538 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3539 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3540 		goto cantfind_ext4;
3541 
3542 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3543 	if (sbi->s_inodes_per_block == 0)
3544 		goto cantfind_ext4;
3545 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3546 					sbi->s_inodes_per_block;
3547 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3548 	sbi->s_sbh = bh;
3549 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3550 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3551 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3552 
3553 	for (i = 0; i < 4; i++)
3554 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3555 	sbi->s_def_hash_version = es->s_def_hash_version;
3556 	i = le32_to_cpu(es->s_flags);
3557 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3558 		sbi->s_hash_unsigned = 3;
3559 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3560 #ifdef __CHAR_UNSIGNED__
3561 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3562 		sbi->s_hash_unsigned = 3;
3563 #else
3564 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3565 #endif
3566 	}
3567 
3568 	/* Handle clustersize */
3569 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3570 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3571 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3572 	if (has_bigalloc) {
3573 		if (clustersize < blocksize) {
3574 			ext4_msg(sb, KERN_ERR,
3575 				 "cluster size (%d) smaller than "
3576 				 "block size (%d)", clustersize, blocksize);
3577 			goto failed_mount;
3578 		}
3579 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3580 			le32_to_cpu(es->s_log_block_size);
3581 		sbi->s_clusters_per_group =
3582 			le32_to_cpu(es->s_clusters_per_group);
3583 		if (sbi->s_clusters_per_group > blocksize * 8) {
3584 			ext4_msg(sb, KERN_ERR,
3585 				 "#clusters per group too big: %lu",
3586 				 sbi->s_clusters_per_group);
3587 			goto failed_mount;
3588 		}
3589 		if (sbi->s_blocks_per_group !=
3590 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3591 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3592 				 "clusters per group (%lu) inconsistent",
3593 				 sbi->s_blocks_per_group,
3594 				 sbi->s_clusters_per_group);
3595 			goto failed_mount;
3596 		}
3597 	} else {
3598 		if (clustersize != blocksize) {
3599 			ext4_warning(sb, "fragment/cluster size (%d) != "
3600 				     "block size (%d)", clustersize,
3601 				     blocksize);
3602 			clustersize = blocksize;
3603 		}
3604 		if (sbi->s_blocks_per_group > blocksize * 8) {
3605 			ext4_msg(sb, KERN_ERR,
3606 				 "#blocks per group too big: %lu",
3607 				 sbi->s_blocks_per_group);
3608 			goto failed_mount;
3609 		}
3610 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3611 		sbi->s_cluster_bits = 0;
3612 	}
3613 	sbi->s_cluster_ratio = clustersize / blocksize;
3614 
3615 	if (sbi->s_inodes_per_group > blocksize * 8) {
3616 		ext4_msg(sb, KERN_ERR,
3617 		       "#inodes per group too big: %lu",
3618 		       sbi->s_inodes_per_group);
3619 		goto failed_mount;
3620 	}
3621 
3622 	/*
3623 	 * Test whether we have more sectors than will fit in sector_t,
3624 	 * and whether the max offset is addressable by the page cache.
3625 	 */
3626 	err = generic_check_addressable(sb->s_blocksize_bits,
3627 					ext4_blocks_count(es));
3628 	if (err) {
3629 		ext4_msg(sb, KERN_ERR, "filesystem"
3630 			 " too large to mount safely on this system");
3631 		if (sizeof(sector_t) < 8)
3632 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3633 		ret = err;
3634 		goto failed_mount;
3635 	}
3636 
3637 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3638 		goto cantfind_ext4;
3639 
3640 	/* check blocks count against device size */
3641 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3642 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3643 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3644 		       "exceeds size of device (%llu blocks)",
3645 		       ext4_blocks_count(es), blocks_count);
3646 		goto failed_mount;
3647 	}
3648 
3649 	/*
3650 	 * It makes no sense for the first data block to be beyond the end
3651 	 * of the filesystem.
3652 	 */
3653 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3654 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3655 			 "block %u is beyond end of filesystem (%llu)",
3656 			 le32_to_cpu(es->s_first_data_block),
3657 			 ext4_blocks_count(es));
3658 		goto failed_mount;
3659 	}
3660 	blocks_count = (ext4_blocks_count(es) -
3661 			le32_to_cpu(es->s_first_data_block) +
3662 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3663 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3664 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3665 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3666 		       "(block count %llu, first data block %u, "
3667 		       "blocks per group %lu)", sbi->s_groups_count,
3668 		       ext4_blocks_count(es),
3669 		       le32_to_cpu(es->s_first_data_block),
3670 		       EXT4_BLOCKS_PER_GROUP(sb));
3671 		goto failed_mount;
3672 	}
3673 	sbi->s_groups_count = blocks_count;
3674 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3675 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3676 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3677 		   EXT4_DESC_PER_BLOCK(sb);
3678 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3679 					  sizeof(struct buffer_head *),
3680 					  GFP_KERNEL);
3681 	if (sbi->s_group_desc == NULL) {
3682 		ext4_msg(sb, KERN_ERR, "not enough memory");
3683 		ret = -ENOMEM;
3684 		goto failed_mount;
3685 	}
3686 
3687 	if (ext4_proc_root)
3688 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3689 
3690 	if (sbi->s_proc)
3691 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3692 				 &ext4_seq_options_fops, sb);
3693 
3694 	bgl_lock_init(sbi->s_blockgroup_lock);
3695 
3696 	for (i = 0; i < db_count; i++) {
3697 		block = descriptor_loc(sb, logical_sb_block, i);
3698 		sbi->s_group_desc[i] = sb_bread(sb, block);
3699 		if (!sbi->s_group_desc[i]) {
3700 			ext4_msg(sb, KERN_ERR,
3701 			       "can't read group descriptor %d", i);
3702 			db_count = i;
3703 			goto failed_mount2;
3704 		}
3705 	}
3706 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3707 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3708 		goto failed_mount2;
3709 	}
3710 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3711 		if (!ext4_fill_flex_info(sb)) {
3712 			ext4_msg(sb, KERN_ERR,
3713 			       "unable to initialize "
3714 			       "flex_bg meta info!");
3715 			goto failed_mount2;
3716 		}
3717 
3718 	sbi->s_gdb_count = db_count;
3719 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3720 	spin_lock_init(&sbi->s_next_gen_lock);
3721 
3722 	init_timer(&sbi->s_err_report);
3723 	sbi->s_err_report.function = print_daily_error_info;
3724 	sbi->s_err_report.data = (unsigned long) sb;
3725 
3726 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3727 			ext4_count_free_clusters(sb));
3728 	if (!err) {
3729 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3730 				ext4_count_free_inodes(sb));
3731 	}
3732 	if (!err) {
3733 		err = percpu_counter_init(&sbi->s_dirs_counter,
3734 				ext4_count_dirs(sb));
3735 	}
3736 	if (!err) {
3737 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3738 	}
3739 	if (err) {
3740 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3741 		ret = err;
3742 		goto failed_mount3;
3743 	}
3744 
3745 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3746 	sbi->s_max_writeback_mb_bump = 128;
3747 
3748 	/*
3749 	 * set up enough so that it can read an inode
3750 	 */
3751 	if (!test_opt(sb, NOLOAD) &&
3752 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3753 		sb->s_op = &ext4_sops;
3754 	else
3755 		sb->s_op = &ext4_nojournal_sops;
3756 	sb->s_export_op = &ext4_export_ops;
3757 	sb->s_xattr = ext4_xattr_handlers;
3758 #ifdef CONFIG_QUOTA
3759 	sb->s_qcop = &ext4_qctl_operations;
3760 	sb->dq_op = &ext4_quota_operations;
3761 
3762 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
3763 		/* Use qctl operations for hidden quota files. */
3764 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3765 	}
3766 #endif
3767 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3768 
3769 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3770 	mutex_init(&sbi->s_orphan_lock);
3771 	sbi->s_resize_flags = 0;
3772 
3773 	sb->s_root = NULL;
3774 
3775 	needs_recovery = (es->s_last_orphan != 0 ||
3776 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3777 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3778 
3779 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3780 	    !(sb->s_flags & MS_RDONLY))
3781 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3782 			goto failed_mount3;
3783 
3784 	/*
3785 	 * The first inode we look at is the journal inode.  Don't try
3786 	 * root first: it may be modified in the journal!
3787 	 */
3788 	if (!test_opt(sb, NOLOAD) &&
3789 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3790 		if (ext4_load_journal(sb, es, journal_devnum))
3791 			goto failed_mount3;
3792 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3793 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3794 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3795 		       "suppressed and not mounted read-only");
3796 		goto failed_mount_wq;
3797 	} else {
3798 		clear_opt(sb, DATA_FLAGS);
3799 		sbi->s_journal = NULL;
3800 		needs_recovery = 0;
3801 		goto no_journal;
3802 	}
3803 
3804 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3805 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3806 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3807 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3808 		goto failed_mount_wq;
3809 	}
3810 
3811 	if (!set_journal_csum_feature_set(sb)) {
3812 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3813 			 "feature set");
3814 		goto failed_mount_wq;
3815 	}
3816 
3817 	/* We have now updated the journal if required, so we can
3818 	 * validate the data journaling mode. */
3819 	switch (test_opt(sb, DATA_FLAGS)) {
3820 	case 0:
3821 		/* No mode set, assume a default based on the journal
3822 		 * capabilities: ORDERED_DATA if the journal can
3823 		 * cope, else JOURNAL_DATA
3824 		 */
3825 		if (jbd2_journal_check_available_features
3826 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3827 			set_opt(sb, ORDERED_DATA);
3828 		else
3829 			set_opt(sb, JOURNAL_DATA);
3830 		break;
3831 
3832 	case EXT4_MOUNT_ORDERED_DATA:
3833 	case EXT4_MOUNT_WRITEBACK_DATA:
3834 		if (!jbd2_journal_check_available_features
3835 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3836 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3837 			       "requested data journaling mode");
3838 			goto failed_mount_wq;
3839 		}
3840 	default:
3841 		break;
3842 	}
3843 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3844 
3845 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3846 
3847 	/*
3848 	 * The journal may have updated the bg summary counts, so we
3849 	 * need to update the global counters.
3850 	 */
3851 	percpu_counter_set(&sbi->s_freeclusters_counter,
3852 			   ext4_count_free_clusters(sb));
3853 	percpu_counter_set(&sbi->s_freeinodes_counter,
3854 			   ext4_count_free_inodes(sb));
3855 	percpu_counter_set(&sbi->s_dirs_counter,
3856 			   ext4_count_dirs(sb));
3857 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3858 
3859 no_journal:
3860 	/*
3861 	 * Get the # of file system overhead blocks from the
3862 	 * superblock if present.
3863 	 */
3864 	if (es->s_overhead_clusters)
3865 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3866 	else {
3867 		ret = ext4_calculate_overhead(sb);
3868 		if (ret)
3869 			goto failed_mount_wq;
3870 	}
3871 
3872 	/*
3873 	 * The maximum number of concurrent works can be high and
3874 	 * concurrency isn't really necessary.  Limit it to 1.
3875 	 */
3876 	EXT4_SB(sb)->dio_unwritten_wq =
3877 		alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3878 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3879 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3880 		goto failed_mount_wq;
3881 	}
3882 
3883 	/*
3884 	 * The jbd2_journal_load will have done any necessary log recovery,
3885 	 * so we can safely mount the rest of the filesystem now.
3886 	 */
3887 
3888 	root = ext4_iget(sb, EXT4_ROOT_INO);
3889 	if (IS_ERR(root)) {
3890 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3891 		ret = PTR_ERR(root);
3892 		root = NULL;
3893 		goto failed_mount4;
3894 	}
3895 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3896 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3897 		iput(root);
3898 		goto failed_mount4;
3899 	}
3900 	sb->s_root = d_make_root(root);
3901 	if (!sb->s_root) {
3902 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3903 		ret = -ENOMEM;
3904 		goto failed_mount4;
3905 	}
3906 
3907 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3908 		sb->s_flags |= MS_RDONLY;
3909 
3910 	/* determine the minimum size of new large inodes, if present */
3911 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3912 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3913 						     EXT4_GOOD_OLD_INODE_SIZE;
3914 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3915 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3916 			if (sbi->s_want_extra_isize <
3917 			    le16_to_cpu(es->s_want_extra_isize))
3918 				sbi->s_want_extra_isize =
3919 					le16_to_cpu(es->s_want_extra_isize);
3920 			if (sbi->s_want_extra_isize <
3921 			    le16_to_cpu(es->s_min_extra_isize))
3922 				sbi->s_want_extra_isize =
3923 					le16_to_cpu(es->s_min_extra_isize);
3924 		}
3925 	}
3926 	/* Check if enough inode space is available */
3927 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3928 							sbi->s_inode_size) {
3929 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3930 						       EXT4_GOOD_OLD_INODE_SIZE;
3931 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3932 			 "available");
3933 	}
3934 
3935 	err = ext4_setup_system_zone(sb);
3936 	if (err) {
3937 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3938 			 "zone (%d)", err);
3939 		goto failed_mount4a;
3940 	}
3941 
3942 	ext4_ext_init(sb);
3943 	err = ext4_mb_init(sb);
3944 	if (err) {
3945 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3946 			 err);
3947 		goto failed_mount5;
3948 	}
3949 
3950 	err = ext4_register_li_request(sb, first_not_zeroed);
3951 	if (err)
3952 		goto failed_mount6;
3953 
3954 	sbi->s_kobj.kset = ext4_kset;
3955 	init_completion(&sbi->s_kobj_unregister);
3956 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3957 				   "%s", sb->s_id);
3958 	if (err)
3959 		goto failed_mount7;
3960 
3961 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3962 	ext4_orphan_cleanup(sb, es);
3963 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3964 	if (needs_recovery) {
3965 		ext4_msg(sb, KERN_INFO, "recovery complete");
3966 		ext4_mark_recovery_complete(sb, es);
3967 	}
3968 	if (EXT4_SB(sb)->s_journal) {
3969 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3970 			descr = " journalled data mode";
3971 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3972 			descr = " ordered data mode";
3973 		else
3974 			descr = " writeback data mode";
3975 	} else
3976 		descr = "out journal";
3977 
3978 #ifdef CONFIG_QUOTA
3979 	/* Enable quota usage during mount. */
3980 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
3981 	    !(sb->s_flags & MS_RDONLY)) {
3982 		ret = ext4_enable_quotas(sb);
3983 		if (ret)
3984 			goto failed_mount7;
3985 	}
3986 #endif  /* CONFIG_QUOTA */
3987 
3988 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3989 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3990 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3991 
3992 	if (es->s_error_count)
3993 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3994 
3995 	kfree(orig_data);
3996 	return 0;
3997 
3998 cantfind_ext4:
3999 	if (!silent)
4000 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4001 	goto failed_mount;
4002 
4003 failed_mount7:
4004 	ext4_unregister_li_request(sb);
4005 failed_mount6:
4006 	ext4_mb_release(sb);
4007 failed_mount5:
4008 	ext4_ext_release(sb);
4009 	ext4_release_system_zone(sb);
4010 failed_mount4a:
4011 	dput(sb->s_root);
4012 	sb->s_root = NULL;
4013 failed_mount4:
4014 	ext4_msg(sb, KERN_ERR, "mount failed");
4015 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4016 failed_mount_wq:
4017 	if (sbi->s_journal) {
4018 		jbd2_journal_destroy(sbi->s_journal);
4019 		sbi->s_journal = NULL;
4020 	}
4021 failed_mount3:
4022 	del_timer(&sbi->s_err_report);
4023 	if (sbi->s_flex_groups)
4024 		ext4_kvfree(sbi->s_flex_groups);
4025 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4026 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4027 	percpu_counter_destroy(&sbi->s_dirs_counter);
4028 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4029 	if (sbi->s_mmp_tsk)
4030 		kthread_stop(sbi->s_mmp_tsk);
4031 failed_mount2:
4032 	for (i = 0; i < db_count; i++)
4033 		brelse(sbi->s_group_desc[i]);
4034 	ext4_kvfree(sbi->s_group_desc);
4035 failed_mount:
4036 	if (sbi->s_chksum_driver)
4037 		crypto_free_shash(sbi->s_chksum_driver);
4038 	if (sbi->s_proc) {
4039 		remove_proc_entry("options", sbi->s_proc);
4040 		remove_proc_entry(sb->s_id, ext4_proc_root);
4041 	}
4042 #ifdef CONFIG_QUOTA
4043 	for (i = 0; i < MAXQUOTAS; i++)
4044 		kfree(sbi->s_qf_names[i]);
4045 #endif
4046 	ext4_blkdev_remove(sbi);
4047 	brelse(bh);
4048 out_fail:
4049 	sb->s_fs_info = NULL;
4050 	kfree(sbi->s_blockgroup_lock);
4051 	kfree(sbi);
4052 out_free_orig:
4053 	kfree(orig_data);
4054 	return ret;
4055 }
4056 
4057 /*
4058  * Setup any per-fs journal parameters now.  We'll do this both on
4059  * initial mount, once the journal has been initialised but before we've
4060  * done any recovery; and again on any subsequent remount.
4061  */
4062 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4063 {
4064 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4065 
4066 	journal->j_commit_interval = sbi->s_commit_interval;
4067 	journal->j_min_batch_time = sbi->s_min_batch_time;
4068 	journal->j_max_batch_time = sbi->s_max_batch_time;
4069 
4070 	write_lock(&journal->j_state_lock);
4071 	if (test_opt(sb, BARRIER))
4072 		journal->j_flags |= JBD2_BARRIER;
4073 	else
4074 		journal->j_flags &= ~JBD2_BARRIER;
4075 	if (test_opt(sb, DATA_ERR_ABORT))
4076 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4077 	else
4078 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4079 	write_unlock(&journal->j_state_lock);
4080 }
4081 
4082 static journal_t *ext4_get_journal(struct super_block *sb,
4083 				   unsigned int journal_inum)
4084 {
4085 	struct inode *journal_inode;
4086 	journal_t *journal;
4087 
4088 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4089 
4090 	/* First, test for the existence of a valid inode on disk.  Bad
4091 	 * things happen if we iget() an unused inode, as the subsequent
4092 	 * iput() will try to delete it. */
4093 
4094 	journal_inode = ext4_iget(sb, journal_inum);
4095 	if (IS_ERR(journal_inode)) {
4096 		ext4_msg(sb, KERN_ERR, "no journal found");
4097 		return NULL;
4098 	}
4099 	if (!journal_inode->i_nlink) {
4100 		make_bad_inode(journal_inode);
4101 		iput(journal_inode);
4102 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4103 		return NULL;
4104 	}
4105 
4106 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4107 		  journal_inode, journal_inode->i_size);
4108 	if (!S_ISREG(journal_inode->i_mode)) {
4109 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4110 		iput(journal_inode);
4111 		return NULL;
4112 	}
4113 
4114 	journal = jbd2_journal_init_inode(journal_inode);
4115 	if (!journal) {
4116 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4117 		iput(journal_inode);
4118 		return NULL;
4119 	}
4120 	journal->j_private = sb;
4121 	ext4_init_journal_params(sb, journal);
4122 	return journal;
4123 }
4124 
4125 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4126 				       dev_t j_dev)
4127 {
4128 	struct buffer_head *bh;
4129 	journal_t *journal;
4130 	ext4_fsblk_t start;
4131 	ext4_fsblk_t len;
4132 	int hblock, blocksize;
4133 	ext4_fsblk_t sb_block;
4134 	unsigned long offset;
4135 	struct ext4_super_block *es;
4136 	struct block_device *bdev;
4137 
4138 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4139 
4140 	bdev = ext4_blkdev_get(j_dev, sb);
4141 	if (bdev == NULL)
4142 		return NULL;
4143 
4144 	blocksize = sb->s_blocksize;
4145 	hblock = bdev_logical_block_size(bdev);
4146 	if (blocksize < hblock) {
4147 		ext4_msg(sb, KERN_ERR,
4148 			"blocksize too small for journal device");
4149 		goto out_bdev;
4150 	}
4151 
4152 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4153 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4154 	set_blocksize(bdev, blocksize);
4155 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4156 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4157 		       "external journal");
4158 		goto out_bdev;
4159 	}
4160 
4161 	es = (struct ext4_super_block *) (bh->b_data + offset);
4162 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4163 	    !(le32_to_cpu(es->s_feature_incompat) &
4164 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4165 		ext4_msg(sb, KERN_ERR, "external journal has "
4166 					"bad superblock");
4167 		brelse(bh);
4168 		goto out_bdev;
4169 	}
4170 
4171 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4172 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4173 		brelse(bh);
4174 		goto out_bdev;
4175 	}
4176 
4177 	len = ext4_blocks_count(es);
4178 	start = sb_block + 1;
4179 	brelse(bh);	/* we're done with the superblock */
4180 
4181 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4182 					start, len, blocksize);
4183 	if (!journal) {
4184 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4185 		goto out_bdev;
4186 	}
4187 	journal->j_private = sb;
4188 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
4189 	wait_on_buffer(journal->j_sb_buffer);
4190 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4191 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4192 		goto out_journal;
4193 	}
4194 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4195 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4196 					"user (unsupported) - %d",
4197 			be32_to_cpu(journal->j_superblock->s_nr_users));
4198 		goto out_journal;
4199 	}
4200 	EXT4_SB(sb)->journal_bdev = bdev;
4201 	ext4_init_journal_params(sb, journal);
4202 	return journal;
4203 
4204 out_journal:
4205 	jbd2_journal_destroy(journal);
4206 out_bdev:
4207 	ext4_blkdev_put(bdev);
4208 	return NULL;
4209 }
4210 
4211 static int ext4_load_journal(struct super_block *sb,
4212 			     struct ext4_super_block *es,
4213 			     unsigned long journal_devnum)
4214 {
4215 	journal_t *journal;
4216 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4217 	dev_t journal_dev;
4218 	int err = 0;
4219 	int really_read_only;
4220 
4221 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4222 
4223 	if (journal_devnum &&
4224 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4225 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4226 			"numbers have changed");
4227 		journal_dev = new_decode_dev(journal_devnum);
4228 	} else
4229 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4230 
4231 	really_read_only = bdev_read_only(sb->s_bdev);
4232 
4233 	/*
4234 	 * Are we loading a blank journal or performing recovery after a
4235 	 * crash?  For recovery, we need to check in advance whether we
4236 	 * can get read-write access to the device.
4237 	 */
4238 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4239 		if (sb->s_flags & MS_RDONLY) {
4240 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4241 					"required on readonly filesystem");
4242 			if (really_read_only) {
4243 				ext4_msg(sb, KERN_ERR, "write access "
4244 					"unavailable, cannot proceed");
4245 				return -EROFS;
4246 			}
4247 			ext4_msg(sb, KERN_INFO, "write access will "
4248 			       "be enabled during recovery");
4249 		}
4250 	}
4251 
4252 	if (journal_inum && journal_dev) {
4253 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4254 		       "and inode journals!");
4255 		return -EINVAL;
4256 	}
4257 
4258 	if (journal_inum) {
4259 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4260 			return -EINVAL;
4261 	} else {
4262 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4263 			return -EINVAL;
4264 	}
4265 
4266 	if (!(journal->j_flags & JBD2_BARRIER))
4267 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4268 
4269 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4270 		err = jbd2_journal_wipe(journal, !really_read_only);
4271 	if (!err) {
4272 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4273 		if (save)
4274 			memcpy(save, ((char *) es) +
4275 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4276 		err = jbd2_journal_load(journal);
4277 		if (save)
4278 			memcpy(((char *) es) + EXT4_S_ERR_START,
4279 			       save, EXT4_S_ERR_LEN);
4280 		kfree(save);
4281 	}
4282 
4283 	if (err) {
4284 		ext4_msg(sb, KERN_ERR, "error loading journal");
4285 		jbd2_journal_destroy(journal);
4286 		return err;
4287 	}
4288 
4289 	EXT4_SB(sb)->s_journal = journal;
4290 	ext4_clear_journal_err(sb, es);
4291 
4292 	if (!really_read_only && journal_devnum &&
4293 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4294 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4295 
4296 		/* Make sure we flush the recovery flag to disk. */
4297 		ext4_commit_super(sb, 1);
4298 	}
4299 
4300 	return 0;
4301 }
4302 
4303 static int ext4_commit_super(struct super_block *sb, int sync)
4304 {
4305 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4306 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4307 	int error = 0;
4308 
4309 	if (!sbh || block_device_ejected(sb))
4310 		return error;
4311 	if (buffer_write_io_error(sbh)) {
4312 		/*
4313 		 * Oh, dear.  A previous attempt to write the
4314 		 * superblock failed.  This could happen because the
4315 		 * USB device was yanked out.  Or it could happen to
4316 		 * be a transient write error and maybe the block will
4317 		 * be remapped.  Nothing we can do but to retry the
4318 		 * write and hope for the best.
4319 		 */
4320 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4321 		       "superblock detected");
4322 		clear_buffer_write_io_error(sbh);
4323 		set_buffer_uptodate(sbh);
4324 	}
4325 	/*
4326 	 * If the file system is mounted read-only, don't update the
4327 	 * superblock write time.  This avoids updating the superblock
4328 	 * write time when we are mounting the root file system
4329 	 * read/only but we need to replay the journal; at that point,
4330 	 * for people who are east of GMT and who make their clock
4331 	 * tick in localtime for Windows bug-for-bug compatibility,
4332 	 * the clock is set in the future, and this will cause e2fsck
4333 	 * to complain and force a full file system check.
4334 	 */
4335 	if (!(sb->s_flags & MS_RDONLY))
4336 		es->s_wtime = cpu_to_le32(get_seconds());
4337 	if (sb->s_bdev->bd_part)
4338 		es->s_kbytes_written =
4339 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4340 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4341 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4342 	else
4343 		es->s_kbytes_written =
4344 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4345 	ext4_free_blocks_count_set(es,
4346 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4347 				&EXT4_SB(sb)->s_freeclusters_counter)));
4348 	es->s_free_inodes_count =
4349 		cpu_to_le32(percpu_counter_sum_positive(
4350 				&EXT4_SB(sb)->s_freeinodes_counter));
4351 	BUFFER_TRACE(sbh, "marking dirty");
4352 	ext4_superblock_csum_set(sb, es);
4353 	mark_buffer_dirty(sbh);
4354 	if (sync) {
4355 		error = sync_dirty_buffer(sbh);
4356 		if (error)
4357 			return error;
4358 
4359 		error = buffer_write_io_error(sbh);
4360 		if (error) {
4361 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4362 			       "superblock");
4363 			clear_buffer_write_io_error(sbh);
4364 			set_buffer_uptodate(sbh);
4365 		}
4366 	}
4367 	return error;
4368 }
4369 
4370 /*
4371  * Have we just finished recovery?  If so, and if we are mounting (or
4372  * remounting) the filesystem readonly, then we will end up with a
4373  * consistent fs on disk.  Record that fact.
4374  */
4375 static void ext4_mark_recovery_complete(struct super_block *sb,
4376 					struct ext4_super_block *es)
4377 {
4378 	journal_t *journal = EXT4_SB(sb)->s_journal;
4379 
4380 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4381 		BUG_ON(journal != NULL);
4382 		return;
4383 	}
4384 	jbd2_journal_lock_updates(journal);
4385 	if (jbd2_journal_flush(journal) < 0)
4386 		goto out;
4387 
4388 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4389 	    sb->s_flags & MS_RDONLY) {
4390 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4391 		ext4_commit_super(sb, 1);
4392 	}
4393 
4394 out:
4395 	jbd2_journal_unlock_updates(journal);
4396 }
4397 
4398 /*
4399  * If we are mounting (or read-write remounting) a filesystem whose journal
4400  * has recorded an error from a previous lifetime, move that error to the
4401  * main filesystem now.
4402  */
4403 static void ext4_clear_journal_err(struct super_block *sb,
4404 				   struct ext4_super_block *es)
4405 {
4406 	journal_t *journal;
4407 	int j_errno;
4408 	const char *errstr;
4409 
4410 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4411 
4412 	journal = EXT4_SB(sb)->s_journal;
4413 
4414 	/*
4415 	 * Now check for any error status which may have been recorded in the
4416 	 * journal by a prior ext4_error() or ext4_abort()
4417 	 */
4418 
4419 	j_errno = jbd2_journal_errno(journal);
4420 	if (j_errno) {
4421 		char nbuf[16];
4422 
4423 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4424 		ext4_warning(sb, "Filesystem error recorded "
4425 			     "from previous mount: %s", errstr);
4426 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4427 
4428 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4429 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4430 		ext4_commit_super(sb, 1);
4431 
4432 		jbd2_journal_clear_err(journal);
4433 	}
4434 }
4435 
4436 /*
4437  * Force the running and committing transactions to commit,
4438  * and wait on the commit.
4439  */
4440 int ext4_force_commit(struct super_block *sb)
4441 {
4442 	journal_t *journal;
4443 	int ret = 0;
4444 
4445 	if (sb->s_flags & MS_RDONLY)
4446 		return 0;
4447 
4448 	journal = EXT4_SB(sb)->s_journal;
4449 	if (journal)
4450 		ret = ext4_journal_force_commit(journal);
4451 
4452 	return ret;
4453 }
4454 
4455 static int ext4_sync_fs(struct super_block *sb, int wait)
4456 {
4457 	int ret = 0;
4458 	tid_t target;
4459 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4460 
4461 	trace_ext4_sync_fs(sb, wait);
4462 	flush_workqueue(sbi->dio_unwritten_wq);
4463 	/*
4464 	 * Writeback quota in non-journalled quota case - journalled quota has
4465 	 * no dirty dquots
4466 	 */
4467 	dquot_writeback_dquots(sb, -1);
4468 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4469 		if (wait)
4470 			jbd2_log_wait_commit(sbi->s_journal, target);
4471 	}
4472 	return ret;
4473 }
4474 
4475 /*
4476  * LVM calls this function before a (read-only) snapshot is created.  This
4477  * gives us a chance to flush the journal completely and mark the fs clean.
4478  *
4479  * Note that only this function cannot bring a filesystem to be in a clean
4480  * state independently. It relies on upper layer to stop all data & metadata
4481  * modifications.
4482  */
4483 static int ext4_freeze(struct super_block *sb)
4484 {
4485 	int error = 0;
4486 	journal_t *journal;
4487 
4488 	if (sb->s_flags & MS_RDONLY)
4489 		return 0;
4490 
4491 	journal = EXT4_SB(sb)->s_journal;
4492 
4493 	/* Now we set up the journal barrier. */
4494 	jbd2_journal_lock_updates(journal);
4495 
4496 	/*
4497 	 * Don't clear the needs_recovery flag if we failed to flush
4498 	 * the journal.
4499 	 */
4500 	error = jbd2_journal_flush(journal);
4501 	if (error < 0)
4502 		goto out;
4503 
4504 	/* Journal blocked and flushed, clear needs_recovery flag. */
4505 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4506 	error = ext4_commit_super(sb, 1);
4507 out:
4508 	/* we rely on upper layer to stop further updates */
4509 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4510 	return error;
4511 }
4512 
4513 /*
4514  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4515  * flag here, even though the filesystem is not technically dirty yet.
4516  */
4517 static int ext4_unfreeze(struct super_block *sb)
4518 {
4519 	if (sb->s_flags & MS_RDONLY)
4520 		return 0;
4521 
4522 	lock_super(sb);
4523 	/* Reset the needs_recovery flag before the fs is unlocked. */
4524 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4525 	ext4_commit_super(sb, 1);
4526 	unlock_super(sb);
4527 	return 0;
4528 }
4529 
4530 /*
4531  * Structure to save mount options for ext4_remount's benefit
4532  */
4533 struct ext4_mount_options {
4534 	unsigned long s_mount_opt;
4535 	unsigned long s_mount_opt2;
4536 	kuid_t s_resuid;
4537 	kgid_t s_resgid;
4538 	unsigned long s_commit_interval;
4539 	u32 s_min_batch_time, s_max_batch_time;
4540 #ifdef CONFIG_QUOTA
4541 	int s_jquota_fmt;
4542 	char *s_qf_names[MAXQUOTAS];
4543 #endif
4544 };
4545 
4546 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4547 {
4548 	struct ext4_super_block *es;
4549 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4550 	unsigned long old_sb_flags;
4551 	struct ext4_mount_options old_opts;
4552 	int enable_quota = 0;
4553 	ext4_group_t g;
4554 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4555 	int err = 0;
4556 #ifdef CONFIG_QUOTA
4557 	int i;
4558 #endif
4559 	char *orig_data = kstrdup(data, GFP_KERNEL);
4560 
4561 	/* Store the original options */
4562 	lock_super(sb);
4563 	old_sb_flags = sb->s_flags;
4564 	old_opts.s_mount_opt = sbi->s_mount_opt;
4565 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4566 	old_opts.s_resuid = sbi->s_resuid;
4567 	old_opts.s_resgid = sbi->s_resgid;
4568 	old_opts.s_commit_interval = sbi->s_commit_interval;
4569 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4570 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4571 #ifdef CONFIG_QUOTA
4572 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4573 	for (i = 0; i < MAXQUOTAS; i++)
4574 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4575 #endif
4576 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4577 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4578 
4579 	/*
4580 	 * Allow the "check" option to be passed as a remount option.
4581 	 */
4582 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4583 		err = -EINVAL;
4584 		goto restore_opts;
4585 	}
4586 
4587 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4588 		ext4_abort(sb, "Abort forced by user");
4589 
4590 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4591 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4592 
4593 	es = sbi->s_es;
4594 
4595 	if (sbi->s_journal) {
4596 		ext4_init_journal_params(sb, sbi->s_journal);
4597 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4598 	}
4599 
4600 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4601 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4602 			err = -EROFS;
4603 			goto restore_opts;
4604 		}
4605 
4606 		if (*flags & MS_RDONLY) {
4607 			err = dquot_suspend(sb, -1);
4608 			if (err < 0)
4609 				goto restore_opts;
4610 
4611 			/*
4612 			 * First of all, the unconditional stuff we have to do
4613 			 * to disable replay of the journal when we next remount
4614 			 */
4615 			sb->s_flags |= MS_RDONLY;
4616 
4617 			/*
4618 			 * OK, test if we are remounting a valid rw partition
4619 			 * readonly, and if so set the rdonly flag and then
4620 			 * mark the partition as valid again.
4621 			 */
4622 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4623 			    (sbi->s_mount_state & EXT4_VALID_FS))
4624 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4625 
4626 			if (sbi->s_journal)
4627 				ext4_mark_recovery_complete(sb, es);
4628 		} else {
4629 			/* Make sure we can mount this feature set readwrite */
4630 			if (!ext4_feature_set_ok(sb, 0)) {
4631 				err = -EROFS;
4632 				goto restore_opts;
4633 			}
4634 			/*
4635 			 * Make sure the group descriptor checksums
4636 			 * are sane.  If they aren't, refuse to remount r/w.
4637 			 */
4638 			for (g = 0; g < sbi->s_groups_count; g++) {
4639 				struct ext4_group_desc *gdp =
4640 					ext4_get_group_desc(sb, g, NULL);
4641 
4642 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4643 					ext4_msg(sb, KERN_ERR,
4644 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4645 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4646 					       le16_to_cpu(gdp->bg_checksum));
4647 					err = -EINVAL;
4648 					goto restore_opts;
4649 				}
4650 			}
4651 
4652 			/*
4653 			 * If we have an unprocessed orphan list hanging
4654 			 * around from a previously readonly bdev mount,
4655 			 * require a full umount/remount for now.
4656 			 */
4657 			if (es->s_last_orphan) {
4658 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4659 				       "remount RDWR because of unprocessed "
4660 				       "orphan inode list.  Please "
4661 				       "umount/remount instead");
4662 				err = -EINVAL;
4663 				goto restore_opts;
4664 			}
4665 
4666 			/*
4667 			 * Mounting a RDONLY partition read-write, so reread
4668 			 * and store the current valid flag.  (It may have
4669 			 * been changed by e2fsck since we originally mounted
4670 			 * the partition.)
4671 			 */
4672 			if (sbi->s_journal)
4673 				ext4_clear_journal_err(sb, es);
4674 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4675 			if (!ext4_setup_super(sb, es, 0))
4676 				sb->s_flags &= ~MS_RDONLY;
4677 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4678 						     EXT4_FEATURE_INCOMPAT_MMP))
4679 				if (ext4_multi_mount_protect(sb,
4680 						le64_to_cpu(es->s_mmp_block))) {
4681 					err = -EROFS;
4682 					goto restore_opts;
4683 				}
4684 			enable_quota = 1;
4685 		}
4686 	}
4687 
4688 	/*
4689 	 * Reinitialize lazy itable initialization thread based on
4690 	 * current settings
4691 	 */
4692 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4693 		ext4_unregister_li_request(sb);
4694 	else {
4695 		ext4_group_t first_not_zeroed;
4696 		first_not_zeroed = ext4_has_uninit_itable(sb);
4697 		ext4_register_li_request(sb, first_not_zeroed);
4698 	}
4699 
4700 	ext4_setup_system_zone(sb);
4701 	if (sbi->s_journal == NULL)
4702 		ext4_commit_super(sb, 1);
4703 
4704 	unlock_super(sb);
4705 #ifdef CONFIG_QUOTA
4706 	/* Release old quota file names */
4707 	for (i = 0; i < MAXQUOTAS; i++)
4708 		if (old_opts.s_qf_names[i] &&
4709 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4710 			kfree(old_opts.s_qf_names[i]);
4711 	if (enable_quota) {
4712 		if (sb_any_quota_suspended(sb))
4713 			dquot_resume(sb, -1);
4714 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4715 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4716 			err = ext4_enable_quotas(sb);
4717 			if (err) {
4718 				lock_super(sb);
4719 				goto restore_opts;
4720 			}
4721 		}
4722 	}
4723 #endif
4724 
4725 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4726 	kfree(orig_data);
4727 	return 0;
4728 
4729 restore_opts:
4730 	sb->s_flags = old_sb_flags;
4731 	sbi->s_mount_opt = old_opts.s_mount_opt;
4732 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4733 	sbi->s_resuid = old_opts.s_resuid;
4734 	sbi->s_resgid = old_opts.s_resgid;
4735 	sbi->s_commit_interval = old_opts.s_commit_interval;
4736 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4737 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4738 #ifdef CONFIG_QUOTA
4739 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4740 	for (i = 0; i < MAXQUOTAS; i++) {
4741 		if (sbi->s_qf_names[i] &&
4742 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4743 			kfree(sbi->s_qf_names[i]);
4744 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4745 	}
4746 #endif
4747 	unlock_super(sb);
4748 	kfree(orig_data);
4749 	return err;
4750 }
4751 
4752 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4753 {
4754 	struct super_block *sb = dentry->d_sb;
4755 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4756 	struct ext4_super_block *es = sbi->s_es;
4757 	ext4_fsblk_t overhead = 0;
4758 	u64 fsid;
4759 	s64 bfree;
4760 
4761 	if (!test_opt(sb, MINIX_DF))
4762 		overhead = sbi->s_overhead;
4763 
4764 	buf->f_type = EXT4_SUPER_MAGIC;
4765 	buf->f_bsize = sb->s_blocksize;
4766 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
4767 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4768 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4769 	/* prevent underflow in case that few free space is available */
4770 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4771 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4772 	if (buf->f_bfree < ext4_r_blocks_count(es))
4773 		buf->f_bavail = 0;
4774 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4775 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4776 	buf->f_namelen = EXT4_NAME_LEN;
4777 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4778 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4779 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4780 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4781 
4782 	return 0;
4783 }
4784 
4785 /* Helper function for writing quotas on sync - we need to start transaction
4786  * before quota file is locked for write. Otherwise the are possible deadlocks:
4787  * Process 1                         Process 2
4788  * ext4_create()                     quota_sync()
4789  *   jbd2_journal_start()                  write_dquot()
4790  *   dquot_initialize()                         down(dqio_mutex)
4791  *     down(dqio_mutex)                    jbd2_journal_start()
4792  *
4793  */
4794 
4795 #ifdef CONFIG_QUOTA
4796 
4797 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4798 {
4799 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4800 }
4801 
4802 static int ext4_write_dquot(struct dquot *dquot)
4803 {
4804 	int ret, err;
4805 	handle_t *handle;
4806 	struct inode *inode;
4807 
4808 	inode = dquot_to_inode(dquot);
4809 	handle = ext4_journal_start(inode,
4810 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4811 	if (IS_ERR(handle))
4812 		return PTR_ERR(handle);
4813 	ret = dquot_commit(dquot);
4814 	err = ext4_journal_stop(handle);
4815 	if (!ret)
4816 		ret = err;
4817 	return ret;
4818 }
4819 
4820 static int ext4_acquire_dquot(struct dquot *dquot)
4821 {
4822 	int ret, err;
4823 	handle_t *handle;
4824 
4825 	handle = ext4_journal_start(dquot_to_inode(dquot),
4826 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4827 	if (IS_ERR(handle))
4828 		return PTR_ERR(handle);
4829 	ret = dquot_acquire(dquot);
4830 	err = ext4_journal_stop(handle);
4831 	if (!ret)
4832 		ret = err;
4833 	return ret;
4834 }
4835 
4836 static int ext4_release_dquot(struct dquot *dquot)
4837 {
4838 	int ret, err;
4839 	handle_t *handle;
4840 
4841 	handle = ext4_journal_start(dquot_to_inode(dquot),
4842 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4843 	if (IS_ERR(handle)) {
4844 		/* Release dquot anyway to avoid endless cycle in dqput() */
4845 		dquot_release(dquot);
4846 		return PTR_ERR(handle);
4847 	}
4848 	ret = dquot_release(dquot);
4849 	err = ext4_journal_stop(handle);
4850 	if (!ret)
4851 		ret = err;
4852 	return ret;
4853 }
4854 
4855 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4856 {
4857 	/* Are we journaling quotas? */
4858 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4859 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4860 		dquot_mark_dquot_dirty(dquot);
4861 		return ext4_write_dquot(dquot);
4862 	} else {
4863 		return dquot_mark_dquot_dirty(dquot);
4864 	}
4865 }
4866 
4867 static int ext4_write_info(struct super_block *sb, int type)
4868 {
4869 	int ret, err;
4870 	handle_t *handle;
4871 
4872 	/* Data block + inode block */
4873 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
4874 	if (IS_ERR(handle))
4875 		return PTR_ERR(handle);
4876 	ret = dquot_commit_info(sb, type);
4877 	err = ext4_journal_stop(handle);
4878 	if (!ret)
4879 		ret = err;
4880 	return ret;
4881 }
4882 
4883 /*
4884  * Turn on quotas during mount time - we need to find
4885  * the quota file and such...
4886  */
4887 static int ext4_quota_on_mount(struct super_block *sb, int type)
4888 {
4889 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4890 					EXT4_SB(sb)->s_jquota_fmt, type);
4891 }
4892 
4893 /*
4894  * Standard function to be called on quota_on
4895  */
4896 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4897 			 struct path *path)
4898 {
4899 	int err;
4900 
4901 	if (!test_opt(sb, QUOTA))
4902 		return -EINVAL;
4903 
4904 	/* Quotafile not on the same filesystem? */
4905 	if (path->dentry->d_sb != sb)
4906 		return -EXDEV;
4907 	/* Journaling quota? */
4908 	if (EXT4_SB(sb)->s_qf_names[type]) {
4909 		/* Quotafile not in fs root? */
4910 		if (path->dentry->d_parent != sb->s_root)
4911 			ext4_msg(sb, KERN_WARNING,
4912 				"Quota file not on filesystem root. "
4913 				"Journaled quota will not work");
4914 	}
4915 
4916 	/*
4917 	 * When we journal data on quota file, we have to flush journal to see
4918 	 * all updates to the file when we bypass pagecache...
4919 	 */
4920 	if (EXT4_SB(sb)->s_journal &&
4921 	    ext4_should_journal_data(path->dentry->d_inode)) {
4922 		/*
4923 		 * We don't need to lock updates but journal_flush() could
4924 		 * otherwise be livelocked...
4925 		 */
4926 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4927 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4928 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4929 		if (err)
4930 			return err;
4931 	}
4932 
4933 	return dquot_quota_on(sb, type, format_id, path);
4934 }
4935 
4936 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4937 			     unsigned int flags)
4938 {
4939 	int err;
4940 	struct inode *qf_inode;
4941 	unsigned long qf_inums[MAXQUOTAS] = {
4942 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4943 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4944 	};
4945 
4946 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4947 
4948 	if (!qf_inums[type])
4949 		return -EPERM;
4950 
4951 	qf_inode = ext4_iget(sb, qf_inums[type]);
4952 	if (IS_ERR(qf_inode)) {
4953 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4954 		return PTR_ERR(qf_inode);
4955 	}
4956 
4957 	err = dquot_enable(qf_inode, type, format_id, flags);
4958 	iput(qf_inode);
4959 
4960 	return err;
4961 }
4962 
4963 /* Enable usage tracking for all quota types. */
4964 static int ext4_enable_quotas(struct super_block *sb)
4965 {
4966 	int type, err = 0;
4967 	unsigned long qf_inums[MAXQUOTAS] = {
4968 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4969 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4970 	};
4971 
4972 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
4973 	for (type = 0; type < MAXQUOTAS; type++) {
4974 		if (qf_inums[type]) {
4975 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
4976 						DQUOT_USAGE_ENABLED);
4977 			if (err) {
4978 				ext4_warning(sb,
4979 					"Failed to enable quota (type=%d) "
4980 					"tracking. Please run e2fsck to fix.",
4981 					type);
4982 				return err;
4983 			}
4984 		}
4985 	}
4986 	return 0;
4987 }
4988 
4989 /*
4990  * quota_on function that is used when QUOTA feature is set.
4991  */
4992 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
4993 				 int format_id)
4994 {
4995 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
4996 		return -EINVAL;
4997 
4998 	/*
4999 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
5000 	 */
5001 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5002 }
5003 
5004 static int ext4_quota_off(struct super_block *sb, int type)
5005 {
5006 	struct inode *inode = sb_dqopt(sb)->files[type];
5007 	handle_t *handle;
5008 
5009 	/* Force all delayed allocation blocks to be allocated.
5010 	 * Caller already holds s_umount sem */
5011 	if (test_opt(sb, DELALLOC))
5012 		sync_filesystem(sb);
5013 
5014 	if (!inode)
5015 		goto out;
5016 
5017 	/* Update modification times of quota files when userspace can
5018 	 * start looking at them */
5019 	handle = ext4_journal_start(inode, 1);
5020 	if (IS_ERR(handle))
5021 		goto out;
5022 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5023 	ext4_mark_inode_dirty(handle, inode);
5024 	ext4_journal_stop(handle);
5025 
5026 out:
5027 	return dquot_quota_off(sb, type);
5028 }
5029 
5030 /*
5031  * quota_off function that is used when QUOTA feature is set.
5032  */
5033 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5034 {
5035 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5036 		return -EINVAL;
5037 
5038 	/* Disable only the limits. */
5039 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5040 }
5041 
5042 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5043  * acquiring the locks... As quota files are never truncated and quota code
5044  * itself serializes the operations (and no one else should touch the files)
5045  * we don't have to be afraid of races */
5046 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5047 			       size_t len, loff_t off)
5048 {
5049 	struct inode *inode = sb_dqopt(sb)->files[type];
5050 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5051 	int err = 0;
5052 	int offset = off & (sb->s_blocksize - 1);
5053 	int tocopy;
5054 	size_t toread;
5055 	struct buffer_head *bh;
5056 	loff_t i_size = i_size_read(inode);
5057 
5058 	if (off > i_size)
5059 		return 0;
5060 	if (off+len > i_size)
5061 		len = i_size-off;
5062 	toread = len;
5063 	while (toread > 0) {
5064 		tocopy = sb->s_blocksize - offset < toread ?
5065 				sb->s_blocksize - offset : toread;
5066 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5067 		if (err)
5068 			return err;
5069 		if (!bh)	/* A hole? */
5070 			memset(data, 0, tocopy);
5071 		else
5072 			memcpy(data, bh->b_data+offset, tocopy);
5073 		brelse(bh);
5074 		offset = 0;
5075 		toread -= tocopy;
5076 		data += tocopy;
5077 		blk++;
5078 	}
5079 	return len;
5080 }
5081 
5082 /* Write to quotafile (we know the transaction is already started and has
5083  * enough credits) */
5084 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5085 				const char *data, size_t len, loff_t off)
5086 {
5087 	struct inode *inode = sb_dqopt(sb)->files[type];
5088 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5089 	int err = 0;
5090 	int offset = off & (sb->s_blocksize - 1);
5091 	struct buffer_head *bh;
5092 	handle_t *handle = journal_current_handle();
5093 
5094 	if (EXT4_SB(sb)->s_journal && !handle) {
5095 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5096 			" cancelled because transaction is not started",
5097 			(unsigned long long)off, (unsigned long long)len);
5098 		return -EIO;
5099 	}
5100 	/*
5101 	 * Since we account only one data block in transaction credits,
5102 	 * then it is impossible to cross a block boundary.
5103 	 */
5104 	if (sb->s_blocksize - offset < len) {
5105 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5106 			" cancelled because not block aligned",
5107 			(unsigned long long)off, (unsigned long long)len);
5108 		return -EIO;
5109 	}
5110 
5111 	bh = ext4_bread(handle, inode, blk, 1, &err);
5112 	if (!bh)
5113 		goto out;
5114 	err = ext4_journal_get_write_access(handle, bh);
5115 	if (err) {
5116 		brelse(bh);
5117 		goto out;
5118 	}
5119 	lock_buffer(bh);
5120 	memcpy(bh->b_data+offset, data, len);
5121 	flush_dcache_page(bh->b_page);
5122 	unlock_buffer(bh);
5123 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5124 	brelse(bh);
5125 out:
5126 	if (err)
5127 		return err;
5128 	if (inode->i_size < off + len) {
5129 		i_size_write(inode, off + len);
5130 		EXT4_I(inode)->i_disksize = inode->i_size;
5131 		ext4_mark_inode_dirty(handle, inode);
5132 	}
5133 	return len;
5134 }
5135 
5136 #endif
5137 
5138 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5139 		       const char *dev_name, void *data)
5140 {
5141 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5142 }
5143 
5144 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5145 static inline void register_as_ext2(void)
5146 {
5147 	int err = register_filesystem(&ext2_fs_type);
5148 	if (err)
5149 		printk(KERN_WARNING
5150 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5151 }
5152 
5153 static inline void unregister_as_ext2(void)
5154 {
5155 	unregister_filesystem(&ext2_fs_type);
5156 }
5157 
5158 static inline int ext2_feature_set_ok(struct super_block *sb)
5159 {
5160 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5161 		return 0;
5162 	if (sb->s_flags & MS_RDONLY)
5163 		return 1;
5164 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5165 		return 0;
5166 	return 1;
5167 }
5168 MODULE_ALIAS("ext2");
5169 #else
5170 static inline void register_as_ext2(void) { }
5171 static inline void unregister_as_ext2(void) { }
5172 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5173 #endif
5174 
5175 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5176 static inline void register_as_ext3(void)
5177 {
5178 	int err = register_filesystem(&ext3_fs_type);
5179 	if (err)
5180 		printk(KERN_WARNING
5181 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5182 }
5183 
5184 static inline void unregister_as_ext3(void)
5185 {
5186 	unregister_filesystem(&ext3_fs_type);
5187 }
5188 
5189 static inline int ext3_feature_set_ok(struct super_block *sb)
5190 {
5191 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5192 		return 0;
5193 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5194 		return 0;
5195 	if (sb->s_flags & MS_RDONLY)
5196 		return 1;
5197 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5198 		return 0;
5199 	return 1;
5200 }
5201 MODULE_ALIAS("ext3");
5202 #else
5203 static inline void register_as_ext3(void) { }
5204 static inline void unregister_as_ext3(void) { }
5205 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5206 #endif
5207 
5208 static struct file_system_type ext4_fs_type = {
5209 	.owner		= THIS_MODULE,
5210 	.name		= "ext4",
5211 	.mount		= ext4_mount,
5212 	.kill_sb	= kill_block_super,
5213 	.fs_flags	= FS_REQUIRES_DEV,
5214 };
5215 
5216 static int __init ext4_init_feat_adverts(void)
5217 {
5218 	struct ext4_features *ef;
5219 	int ret = -ENOMEM;
5220 
5221 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5222 	if (!ef)
5223 		goto out;
5224 
5225 	ef->f_kobj.kset = ext4_kset;
5226 	init_completion(&ef->f_kobj_unregister);
5227 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5228 				   "features");
5229 	if (ret) {
5230 		kfree(ef);
5231 		goto out;
5232 	}
5233 
5234 	ext4_feat = ef;
5235 	ret = 0;
5236 out:
5237 	return ret;
5238 }
5239 
5240 static void ext4_exit_feat_adverts(void)
5241 {
5242 	kobject_put(&ext4_feat->f_kobj);
5243 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5244 	kfree(ext4_feat);
5245 }
5246 
5247 /* Shared across all ext4 file systems */
5248 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5249 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5250 
5251 static int __init ext4_init_fs(void)
5252 {
5253 	int i, err;
5254 
5255 	ext4_li_info = NULL;
5256 	mutex_init(&ext4_li_mtx);
5257 
5258 	ext4_check_flag_values();
5259 
5260 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5261 		mutex_init(&ext4__aio_mutex[i]);
5262 		init_waitqueue_head(&ext4__ioend_wq[i]);
5263 	}
5264 
5265 	err = ext4_init_pageio();
5266 	if (err)
5267 		return err;
5268 	err = ext4_init_system_zone();
5269 	if (err)
5270 		goto out6;
5271 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5272 	if (!ext4_kset)
5273 		goto out5;
5274 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5275 
5276 	err = ext4_init_feat_adverts();
5277 	if (err)
5278 		goto out4;
5279 
5280 	err = ext4_init_mballoc();
5281 	if (err)
5282 		goto out3;
5283 
5284 	err = ext4_init_xattr();
5285 	if (err)
5286 		goto out2;
5287 	err = init_inodecache();
5288 	if (err)
5289 		goto out1;
5290 	register_as_ext3();
5291 	register_as_ext2();
5292 	err = register_filesystem(&ext4_fs_type);
5293 	if (err)
5294 		goto out;
5295 
5296 	return 0;
5297 out:
5298 	unregister_as_ext2();
5299 	unregister_as_ext3();
5300 	destroy_inodecache();
5301 out1:
5302 	ext4_exit_xattr();
5303 out2:
5304 	ext4_exit_mballoc();
5305 out3:
5306 	ext4_exit_feat_adverts();
5307 out4:
5308 	if (ext4_proc_root)
5309 		remove_proc_entry("fs/ext4", NULL);
5310 	kset_unregister(ext4_kset);
5311 out5:
5312 	ext4_exit_system_zone();
5313 out6:
5314 	ext4_exit_pageio();
5315 	return err;
5316 }
5317 
5318 static void __exit ext4_exit_fs(void)
5319 {
5320 	ext4_destroy_lazyinit_thread();
5321 	unregister_as_ext2();
5322 	unregister_as_ext3();
5323 	unregister_filesystem(&ext4_fs_type);
5324 	destroy_inodecache();
5325 	ext4_exit_xattr();
5326 	ext4_exit_mballoc();
5327 	ext4_exit_feat_adverts();
5328 	remove_proc_entry("fs/ext4", NULL);
5329 	kset_unregister(ext4_kset);
5330 	ext4_exit_system_zone();
5331 	ext4_exit_pageio();
5332 }
5333 
5334 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5335 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5336 MODULE_LICENSE("GPL");
5337 module_init(ext4_init_fs)
5338 module_exit(ext4_exit_fs)
5339