xref: /linux/fs/ext4/super.c (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
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 {
148 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
149 
150 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
151 		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
152 		return;
153 
154 	es->s_checksum = ext4_superblock_csum(sb, es);
155 }
156 
157 void *ext4_kvmalloc(size_t size, gfp_t flags)
158 {
159 	void *ret;
160 
161 	ret = kmalloc(size, flags);
162 	if (!ret)
163 		ret = __vmalloc(size, flags, PAGE_KERNEL);
164 	return ret;
165 }
166 
167 void *ext4_kvzalloc(size_t size, gfp_t flags)
168 {
169 	void *ret;
170 
171 	ret = kzalloc(size, flags);
172 	if (!ret)
173 		ret = __vmalloc(size, flags | __GFP_ZERO, PAGE_KERNEL);
174 	return ret;
175 }
176 
177 void ext4_kvfree(void *ptr)
178 {
179 	if (is_vmalloc_addr(ptr))
180 		vfree(ptr);
181 	else
182 		kfree(ptr);
183 
184 }
185 
186 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
187 			       struct ext4_group_desc *bg)
188 {
189 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
190 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
191 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
192 }
193 
194 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
195 			       struct ext4_group_desc *bg)
196 {
197 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
198 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
199 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
200 }
201 
202 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
203 			      struct ext4_group_desc *bg)
204 {
205 	return le32_to_cpu(bg->bg_inode_table_lo) |
206 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
207 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
208 }
209 
210 __u32 ext4_free_group_clusters(struct super_block *sb,
211 			       struct ext4_group_desc *bg)
212 {
213 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
214 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
215 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
216 }
217 
218 __u32 ext4_free_inodes_count(struct super_block *sb,
219 			      struct ext4_group_desc *bg)
220 {
221 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
222 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
223 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
224 }
225 
226 __u32 ext4_used_dirs_count(struct super_block *sb,
227 			      struct ext4_group_desc *bg)
228 {
229 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
230 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
231 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
232 }
233 
234 __u32 ext4_itable_unused_count(struct super_block *sb,
235 			      struct ext4_group_desc *bg)
236 {
237 	return le16_to_cpu(bg->bg_itable_unused_lo) |
238 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
239 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
240 }
241 
242 void ext4_block_bitmap_set(struct super_block *sb,
243 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
244 {
245 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
246 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
247 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
248 }
249 
250 void ext4_inode_bitmap_set(struct super_block *sb,
251 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
252 {
253 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
254 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
255 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
256 }
257 
258 void ext4_inode_table_set(struct super_block *sb,
259 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
260 {
261 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
262 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
263 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
264 }
265 
266 void ext4_free_group_clusters_set(struct super_block *sb,
267 				  struct ext4_group_desc *bg, __u32 count)
268 {
269 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
270 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
271 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
272 }
273 
274 void ext4_free_inodes_set(struct super_block *sb,
275 			  struct ext4_group_desc *bg, __u32 count)
276 {
277 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
278 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
279 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
280 }
281 
282 void ext4_used_dirs_set(struct super_block *sb,
283 			  struct ext4_group_desc *bg, __u32 count)
284 {
285 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
286 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
287 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
288 }
289 
290 void ext4_itable_unused_set(struct super_block *sb,
291 			  struct ext4_group_desc *bg, __u32 count)
292 {
293 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
294 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
295 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
296 }
297 
298 
299 /* Just increment the non-pointer handle value */
300 static handle_t *ext4_get_nojournal(void)
301 {
302 	handle_t *handle = current->journal_info;
303 	unsigned long ref_cnt = (unsigned long)handle;
304 
305 	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
306 
307 	ref_cnt++;
308 	handle = (handle_t *)ref_cnt;
309 
310 	current->journal_info = handle;
311 	return handle;
312 }
313 
314 
315 /* Decrement the non-pointer handle value */
316 static void ext4_put_nojournal(handle_t *handle)
317 {
318 	unsigned long ref_cnt = (unsigned long)handle;
319 
320 	BUG_ON(ref_cnt == 0);
321 
322 	ref_cnt--;
323 	handle = (handle_t *)ref_cnt;
324 
325 	current->journal_info = handle;
326 }
327 
328 /*
329  * Wrappers for jbd2_journal_start/end.
330  */
331 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
332 {
333 	journal_t *journal;
334 
335 	trace_ext4_journal_start(sb, nblocks, _RET_IP_);
336 	if (sb->s_flags & MS_RDONLY)
337 		return ERR_PTR(-EROFS);
338 
339 	WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE);
340 	journal = EXT4_SB(sb)->s_journal;
341 	if (!journal)
342 		return ext4_get_nojournal();
343 	/*
344 	 * Special case here: if the journal has aborted behind our
345 	 * backs (eg. EIO in the commit thread), then we still need to
346 	 * take the FS itself readonly cleanly.
347 	 */
348 	if (is_journal_aborted(journal)) {
349 		ext4_abort(sb, "Detected aborted journal");
350 		return ERR_PTR(-EROFS);
351 	}
352 	return jbd2_journal_start(journal, nblocks);
353 }
354 
355 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
356 {
357 	struct super_block *sb;
358 	int err;
359 	int rc;
360 
361 	if (!ext4_handle_valid(handle)) {
362 		ext4_put_nojournal(handle);
363 		return 0;
364 	}
365 	sb = handle->h_transaction->t_journal->j_private;
366 	err = handle->h_err;
367 	rc = jbd2_journal_stop(handle);
368 
369 	if (!err)
370 		err = rc;
371 	if (err)
372 		__ext4_std_error(sb, where, line, err);
373 	return err;
374 }
375 
376 void ext4_journal_abort_handle(const char *caller, unsigned int line,
377 			       const char *err_fn, struct buffer_head *bh,
378 			       handle_t *handle, int err)
379 {
380 	char nbuf[16];
381 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
382 
383 	BUG_ON(!ext4_handle_valid(handle));
384 
385 	if (bh)
386 		BUFFER_TRACE(bh, "abort");
387 
388 	if (!handle->h_err)
389 		handle->h_err = err;
390 
391 	if (is_handle_aborted(handle))
392 		return;
393 
394 	printk(KERN_ERR "EXT4-fs: %s:%d: aborting transaction: %s in %s\n",
395 	       caller, line, errstr, err_fn);
396 
397 	jbd2_journal_abort_handle(handle);
398 }
399 
400 static void __save_error_info(struct super_block *sb, const char *func,
401 			    unsigned int line)
402 {
403 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
404 
405 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
406 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
407 	es->s_last_error_time = cpu_to_le32(get_seconds());
408 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
409 	es->s_last_error_line = cpu_to_le32(line);
410 	if (!es->s_first_error_time) {
411 		es->s_first_error_time = es->s_last_error_time;
412 		strncpy(es->s_first_error_func, func,
413 			sizeof(es->s_first_error_func));
414 		es->s_first_error_line = cpu_to_le32(line);
415 		es->s_first_error_ino = es->s_last_error_ino;
416 		es->s_first_error_block = es->s_last_error_block;
417 	}
418 	/*
419 	 * Start the daily error reporting function if it hasn't been
420 	 * started already
421 	 */
422 	if (!es->s_error_count)
423 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
424 	le32_add_cpu(&es->s_error_count, 1);
425 }
426 
427 static void save_error_info(struct super_block *sb, const char *func,
428 			    unsigned int line)
429 {
430 	__save_error_info(sb, func, line);
431 	ext4_commit_super(sb, 1);
432 }
433 
434 /*
435  * The del_gendisk() function uninitializes the disk-specific data
436  * structures, including the bdi structure, without telling anyone
437  * else.  Once this happens, any attempt to call mark_buffer_dirty()
438  * (for example, by ext4_commit_super), will cause a kernel OOPS.
439  * This is a kludge to prevent these oops until we can put in a proper
440  * hook in del_gendisk() to inform the VFS and file system layers.
441  */
442 static int block_device_ejected(struct super_block *sb)
443 {
444 	struct inode *bd_inode = sb->s_bdev->bd_inode;
445 	struct backing_dev_info *bdi = bd_inode->i_mapping->backing_dev_info;
446 
447 	return bdi->dev == NULL;
448 }
449 
450 static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
451 {
452 	struct super_block		*sb = journal->j_private;
453 	struct ext4_sb_info		*sbi = EXT4_SB(sb);
454 	int				error = is_journal_aborted(journal);
455 	struct ext4_journal_cb_entry	*jce, *tmp;
456 
457 	spin_lock(&sbi->s_md_lock);
458 	list_for_each_entry_safe(jce, tmp, &txn->t_private_list, jce_list) {
459 		list_del_init(&jce->jce_list);
460 		spin_unlock(&sbi->s_md_lock);
461 		jce->jce_func(sb, jce, error);
462 		spin_lock(&sbi->s_md_lock);
463 	}
464 	spin_unlock(&sbi->s_md_lock);
465 }
466 
467 /* Deal with the reporting of failure conditions on a filesystem such as
468  * inconsistencies detected or read IO failures.
469  *
470  * On ext2, we can store the error state of the filesystem in the
471  * superblock.  That is not possible on ext4, because we may have other
472  * write ordering constraints on the superblock which prevent us from
473  * writing it out straight away; and given that the journal is about to
474  * be aborted, we can't rely on the current, or future, transactions to
475  * write out the superblock safely.
476  *
477  * We'll just use the jbd2_journal_abort() error code to record an error in
478  * the journal instead.  On recovery, the journal will complain about
479  * that error until we've noted it down and cleared it.
480  */
481 
482 static void ext4_handle_error(struct super_block *sb)
483 {
484 	if (sb->s_flags & MS_RDONLY)
485 		return;
486 
487 	if (!test_opt(sb, ERRORS_CONT)) {
488 		journal_t *journal = EXT4_SB(sb)->s_journal;
489 
490 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
491 		if (journal)
492 			jbd2_journal_abort(journal, -EIO);
493 	}
494 	if (test_opt(sb, ERRORS_RO)) {
495 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
496 		sb->s_flags |= MS_RDONLY;
497 	}
498 	if (test_opt(sb, ERRORS_PANIC))
499 		panic("EXT4-fs (device %s): panic forced after error\n",
500 			sb->s_id);
501 }
502 
503 void __ext4_error(struct super_block *sb, const char *function,
504 		  unsigned int line, const char *fmt, ...)
505 {
506 	struct va_format vaf;
507 	va_list args;
508 
509 	va_start(args, fmt);
510 	vaf.fmt = fmt;
511 	vaf.va = &args;
512 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
513 	       sb->s_id, function, line, current->comm, &vaf);
514 	va_end(args);
515 	save_error_info(sb, function, line);
516 
517 	ext4_handle_error(sb);
518 }
519 
520 void ext4_error_inode(struct inode *inode, const char *function,
521 		      unsigned int line, ext4_fsblk_t block,
522 		      const char *fmt, ...)
523 {
524 	va_list args;
525 	struct va_format vaf;
526 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
527 
528 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
529 	es->s_last_error_block = cpu_to_le64(block);
530 	save_error_info(inode->i_sb, function, line);
531 	va_start(args, fmt);
532 	vaf.fmt = fmt;
533 	vaf.va = &args;
534 	if (block)
535 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
536 		       "inode #%lu: block %llu: comm %s: %pV\n",
537 		       inode->i_sb->s_id, function, line, inode->i_ino,
538 		       block, current->comm, &vaf);
539 	else
540 		printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: "
541 		       "inode #%lu: comm %s: %pV\n",
542 		       inode->i_sb->s_id, function, line, inode->i_ino,
543 		       current->comm, &vaf);
544 	va_end(args);
545 
546 	ext4_handle_error(inode->i_sb);
547 }
548 
549 void ext4_error_file(struct file *file, const char *function,
550 		     unsigned int line, ext4_fsblk_t block,
551 		     const char *fmt, ...)
552 {
553 	va_list args;
554 	struct va_format vaf;
555 	struct ext4_super_block *es;
556 	struct inode *inode = file->f_dentry->d_inode;
557 	char pathname[80], *path;
558 
559 	es = EXT4_SB(inode->i_sb)->s_es;
560 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
561 	save_error_info(inode->i_sb, function, line);
562 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
563 	if (IS_ERR(path))
564 		path = "(unknown)";
565 	va_start(args, fmt);
566 	vaf.fmt = fmt;
567 	vaf.va = &args;
568 	if (block)
569 		printk(KERN_CRIT
570 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
571 		       "block %llu: comm %s: path %s: %pV\n",
572 		       inode->i_sb->s_id, function, line, inode->i_ino,
573 		       block, current->comm, path, &vaf);
574 	else
575 		printk(KERN_CRIT
576 		       "EXT4-fs error (device %s): %s:%d: inode #%lu: "
577 		       "comm %s: path %s: %pV\n",
578 		       inode->i_sb->s_id, function, line, inode->i_ino,
579 		       current->comm, path, &vaf);
580 	va_end(args);
581 
582 	ext4_handle_error(inode->i_sb);
583 }
584 
585 static const char *ext4_decode_error(struct super_block *sb, int errno,
586 				     char nbuf[16])
587 {
588 	char *errstr = NULL;
589 
590 	switch (errno) {
591 	case -EIO:
592 		errstr = "IO failure";
593 		break;
594 	case -ENOMEM:
595 		errstr = "Out of memory";
596 		break;
597 	case -EROFS:
598 		if (!sb || (EXT4_SB(sb)->s_journal &&
599 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
600 			errstr = "Journal has aborted";
601 		else
602 			errstr = "Readonly filesystem";
603 		break;
604 	default:
605 		/* If the caller passed in an extra buffer for unknown
606 		 * errors, textualise them now.  Else we just return
607 		 * NULL. */
608 		if (nbuf) {
609 			/* Check for truncated error codes... */
610 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
611 				errstr = nbuf;
612 		}
613 		break;
614 	}
615 
616 	return errstr;
617 }
618 
619 /* __ext4_std_error decodes expected errors from journaling functions
620  * automatically and invokes the appropriate error response.  */
621 
622 void __ext4_std_error(struct super_block *sb, const char *function,
623 		      unsigned int line, int errno)
624 {
625 	char nbuf[16];
626 	const char *errstr;
627 
628 	/* Special case: if the error is EROFS, and we're not already
629 	 * inside a transaction, then there's really no point in logging
630 	 * an error. */
631 	if (errno == -EROFS && journal_current_handle() == NULL &&
632 	    (sb->s_flags & MS_RDONLY))
633 		return;
634 
635 	errstr = ext4_decode_error(sb, errno, nbuf);
636 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
637 	       sb->s_id, function, line, errstr);
638 	save_error_info(sb, function, line);
639 
640 	ext4_handle_error(sb);
641 }
642 
643 /*
644  * ext4_abort is a much stronger failure handler than ext4_error.  The
645  * abort function may be used to deal with unrecoverable failures such
646  * as journal IO errors or ENOMEM at a critical moment in log management.
647  *
648  * We unconditionally force the filesystem into an ABORT|READONLY state,
649  * unless the error response on the fs has been set to panic in which
650  * case we take the easy way out and panic immediately.
651  */
652 
653 void __ext4_abort(struct super_block *sb, const char *function,
654 		unsigned int line, const char *fmt, ...)
655 {
656 	va_list args;
657 
658 	save_error_info(sb, function, line);
659 	va_start(args, fmt);
660 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
661 	       function, line);
662 	vprintk(fmt, args);
663 	printk("\n");
664 	va_end(args);
665 
666 	if ((sb->s_flags & MS_RDONLY) == 0) {
667 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
668 		sb->s_flags |= MS_RDONLY;
669 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
670 		if (EXT4_SB(sb)->s_journal)
671 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
672 		save_error_info(sb, function, line);
673 	}
674 	if (test_opt(sb, ERRORS_PANIC))
675 		panic("EXT4-fs panic from previous error\n");
676 }
677 
678 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
679 {
680 	struct va_format vaf;
681 	va_list args;
682 
683 	va_start(args, fmt);
684 	vaf.fmt = fmt;
685 	vaf.va = &args;
686 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
687 	va_end(args);
688 }
689 
690 void __ext4_warning(struct super_block *sb, const char *function,
691 		    unsigned int line, const char *fmt, ...)
692 {
693 	struct va_format vaf;
694 	va_list args;
695 
696 	va_start(args, fmt);
697 	vaf.fmt = fmt;
698 	vaf.va = &args;
699 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
700 	       sb->s_id, function, line, &vaf);
701 	va_end(args);
702 }
703 
704 void __ext4_grp_locked_error(const char *function, unsigned int line,
705 			     struct super_block *sb, ext4_group_t grp,
706 			     unsigned long ino, ext4_fsblk_t block,
707 			     const char *fmt, ...)
708 __releases(bitlock)
709 __acquires(bitlock)
710 {
711 	struct va_format vaf;
712 	va_list args;
713 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
714 
715 	es->s_last_error_ino = cpu_to_le32(ino);
716 	es->s_last_error_block = cpu_to_le64(block);
717 	__save_error_info(sb, function, line);
718 
719 	va_start(args, fmt);
720 
721 	vaf.fmt = fmt;
722 	vaf.va = &args;
723 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u, ",
724 	       sb->s_id, function, line, grp);
725 	if (ino)
726 		printk(KERN_CONT "inode %lu: ", ino);
727 	if (block)
728 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
729 	printk(KERN_CONT "%pV\n", &vaf);
730 	va_end(args);
731 
732 	if (test_opt(sb, ERRORS_CONT)) {
733 		ext4_commit_super(sb, 0);
734 		return;
735 	}
736 
737 	ext4_unlock_group(sb, grp);
738 	ext4_handle_error(sb);
739 	/*
740 	 * We only get here in the ERRORS_RO case; relocking the group
741 	 * may be dangerous, but nothing bad will happen since the
742 	 * filesystem will have already been marked read/only and the
743 	 * journal has been aborted.  We return 1 as a hint to callers
744 	 * who might what to use the return value from
745 	 * ext4_grp_locked_error() to distinguish between the
746 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
747 	 * aggressively from the ext4 function in question, with a
748 	 * more appropriate error code.
749 	 */
750 	ext4_lock_group(sb, grp);
751 	return;
752 }
753 
754 void ext4_update_dynamic_rev(struct super_block *sb)
755 {
756 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
757 
758 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
759 		return;
760 
761 	ext4_warning(sb,
762 		     "updating to rev %d because of new feature flag, "
763 		     "running e2fsck is recommended",
764 		     EXT4_DYNAMIC_REV);
765 
766 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
767 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
768 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
769 	/* leave es->s_feature_*compat flags alone */
770 	/* es->s_uuid will be set by e2fsck if empty */
771 
772 	/*
773 	 * The rest of the superblock fields should be zero, and if not it
774 	 * means they are likely already in use, so leave them alone.  We
775 	 * can leave it up to e2fsck to clean up any inconsistencies there.
776 	 */
777 }
778 
779 /*
780  * Open the external journal device
781  */
782 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
783 {
784 	struct block_device *bdev;
785 	char b[BDEVNAME_SIZE];
786 
787 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
788 	if (IS_ERR(bdev))
789 		goto fail;
790 	return bdev;
791 
792 fail:
793 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
794 			__bdevname(dev, b), PTR_ERR(bdev));
795 	return NULL;
796 }
797 
798 /*
799  * Release the journal device
800  */
801 static int ext4_blkdev_put(struct block_device *bdev)
802 {
803 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
804 }
805 
806 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
807 {
808 	struct block_device *bdev;
809 	int ret = -ENODEV;
810 
811 	bdev = sbi->journal_bdev;
812 	if (bdev) {
813 		ret = ext4_blkdev_put(bdev);
814 		sbi->journal_bdev = NULL;
815 	}
816 	return ret;
817 }
818 
819 static inline struct inode *orphan_list_entry(struct list_head *l)
820 {
821 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
822 }
823 
824 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
825 {
826 	struct list_head *l;
827 
828 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
829 		 le32_to_cpu(sbi->s_es->s_last_orphan));
830 
831 	printk(KERN_ERR "sb_info orphan list:\n");
832 	list_for_each(l, &sbi->s_orphan) {
833 		struct inode *inode = orphan_list_entry(l);
834 		printk(KERN_ERR "  "
835 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
836 		       inode->i_sb->s_id, inode->i_ino, inode,
837 		       inode->i_mode, inode->i_nlink,
838 		       NEXT_ORPHAN(inode));
839 	}
840 }
841 
842 static void ext4_put_super(struct super_block *sb)
843 {
844 	struct ext4_sb_info *sbi = EXT4_SB(sb);
845 	struct ext4_super_block *es = sbi->s_es;
846 	int i, err;
847 
848 	ext4_unregister_li_request(sb);
849 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
850 
851 	flush_workqueue(sbi->dio_unwritten_wq);
852 	destroy_workqueue(sbi->dio_unwritten_wq);
853 
854 	if (sbi->s_journal) {
855 		err = jbd2_journal_destroy(sbi->s_journal);
856 		sbi->s_journal = NULL;
857 		if (err < 0)
858 			ext4_abort(sb, "Couldn't clean up the journal");
859 	}
860 
861 	del_timer(&sbi->s_err_report);
862 	ext4_release_system_zone(sb);
863 	ext4_mb_release(sb);
864 	ext4_ext_release(sb);
865 	ext4_xattr_put_super(sb);
866 
867 	if (!(sb->s_flags & MS_RDONLY)) {
868 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
869 		es->s_state = cpu_to_le16(sbi->s_mount_state);
870 	}
871 	if (!(sb->s_flags & MS_RDONLY))
872 		ext4_commit_super(sb, 1);
873 
874 	if (sbi->s_proc) {
875 		remove_proc_entry("options", sbi->s_proc);
876 		remove_proc_entry(sb->s_id, ext4_proc_root);
877 	}
878 	kobject_del(&sbi->s_kobj);
879 
880 	for (i = 0; i < sbi->s_gdb_count; i++)
881 		brelse(sbi->s_group_desc[i]);
882 	ext4_kvfree(sbi->s_group_desc);
883 	ext4_kvfree(sbi->s_flex_groups);
884 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
885 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
886 	percpu_counter_destroy(&sbi->s_dirs_counter);
887 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
888 	brelse(sbi->s_sbh);
889 #ifdef CONFIG_QUOTA
890 	for (i = 0; i < MAXQUOTAS; i++)
891 		kfree(sbi->s_qf_names[i]);
892 #endif
893 
894 	/* Debugging code just in case the in-memory inode orphan list
895 	 * isn't empty.  The on-disk one can be non-empty if we've
896 	 * detected an error and taken the fs readonly, but the
897 	 * in-memory list had better be clean by this point. */
898 	if (!list_empty(&sbi->s_orphan))
899 		dump_orphan_list(sb, sbi);
900 	J_ASSERT(list_empty(&sbi->s_orphan));
901 
902 	invalidate_bdev(sb->s_bdev);
903 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
904 		/*
905 		 * Invalidate the journal device's buffers.  We don't want them
906 		 * floating about in memory - the physical journal device may
907 		 * hotswapped, and it breaks the `ro-after' testing code.
908 		 */
909 		sync_blockdev(sbi->journal_bdev);
910 		invalidate_bdev(sbi->journal_bdev);
911 		ext4_blkdev_remove(sbi);
912 	}
913 	if (sbi->s_mmp_tsk)
914 		kthread_stop(sbi->s_mmp_tsk);
915 	sb->s_fs_info = NULL;
916 	/*
917 	 * Now that we are completely done shutting down the
918 	 * superblock, we need to actually destroy the kobject.
919 	 */
920 	kobject_put(&sbi->s_kobj);
921 	wait_for_completion(&sbi->s_kobj_unregister);
922 	if (sbi->s_chksum_driver)
923 		crypto_free_shash(sbi->s_chksum_driver);
924 	kfree(sbi->s_blockgroup_lock);
925 	kfree(sbi);
926 }
927 
928 static struct kmem_cache *ext4_inode_cachep;
929 
930 /*
931  * Called inside transaction, so use GFP_NOFS
932  */
933 static struct inode *ext4_alloc_inode(struct super_block *sb)
934 {
935 	struct ext4_inode_info *ei;
936 
937 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
938 	if (!ei)
939 		return NULL;
940 
941 	ei->vfs_inode.i_version = 1;
942 	ei->vfs_inode.i_data.writeback_index = 0;
943 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
944 	INIT_LIST_HEAD(&ei->i_prealloc_list);
945 	spin_lock_init(&ei->i_prealloc_lock);
946 	ei->i_reserved_data_blocks = 0;
947 	ei->i_reserved_meta_blocks = 0;
948 	ei->i_allocated_meta_blocks = 0;
949 	ei->i_da_metadata_calc_len = 0;
950 	ei->i_da_metadata_calc_last_lblock = 0;
951 	spin_lock_init(&(ei->i_block_reservation_lock));
952 #ifdef CONFIG_QUOTA
953 	ei->i_reserved_quota = 0;
954 #endif
955 	ei->jinode = NULL;
956 	INIT_LIST_HEAD(&ei->i_completed_io_list);
957 	spin_lock_init(&ei->i_completed_io_lock);
958 	ei->i_sync_tid = 0;
959 	ei->i_datasync_tid = 0;
960 	atomic_set(&ei->i_ioend_count, 0);
961 	atomic_set(&ei->i_unwritten, 0);
962 
963 	return &ei->vfs_inode;
964 }
965 
966 static int ext4_drop_inode(struct inode *inode)
967 {
968 	int drop = generic_drop_inode(inode);
969 
970 	trace_ext4_drop_inode(inode, drop);
971 	return drop;
972 }
973 
974 static void ext4_i_callback(struct rcu_head *head)
975 {
976 	struct inode *inode = container_of(head, struct inode, i_rcu);
977 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
978 }
979 
980 static void ext4_destroy_inode(struct inode *inode)
981 {
982 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
983 		ext4_msg(inode->i_sb, KERN_ERR,
984 			 "Inode %lu (%p): orphan list check failed!",
985 			 inode->i_ino, EXT4_I(inode));
986 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
987 				EXT4_I(inode), sizeof(struct ext4_inode_info),
988 				true);
989 		dump_stack();
990 	}
991 	call_rcu(&inode->i_rcu, ext4_i_callback);
992 }
993 
994 static void init_once(void *foo)
995 {
996 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
997 
998 	INIT_LIST_HEAD(&ei->i_orphan);
999 #ifdef CONFIG_EXT4_FS_XATTR
1000 	init_rwsem(&ei->xattr_sem);
1001 #endif
1002 	init_rwsem(&ei->i_data_sem);
1003 	inode_init_once(&ei->vfs_inode);
1004 }
1005 
1006 static int init_inodecache(void)
1007 {
1008 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
1009 					     sizeof(struct ext4_inode_info),
1010 					     0, (SLAB_RECLAIM_ACCOUNT|
1011 						SLAB_MEM_SPREAD),
1012 					     init_once);
1013 	if (ext4_inode_cachep == NULL)
1014 		return -ENOMEM;
1015 	return 0;
1016 }
1017 
1018 static void destroy_inodecache(void)
1019 {
1020 	/*
1021 	 * Make sure all delayed rcu free inodes are flushed before we
1022 	 * destroy cache.
1023 	 */
1024 	rcu_barrier();
1025 	kmem_cache_destroy(ext4_inode_cachep);
1026 }
1027 
1028 void ext4_clear_inode(struct inode *inode)
1029 {
1030 	invalidate_inode_buffers(inode);
1031 	clear_inode(inode);
1032 	dquot_drop(inode);
1033 	ext4_discard_preallocations(inode);
1034 	if (EXT4_I(inode)->jinode) {
1035 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
1036 					       EXT4_I(inode)->jinode);
1037 		jbd2_free_inode(EXT4_I(inode)->jinode);
1038 		EXT4_I(inode)->jinode = NULL;
1039 	}
1040 }
1041 
1042 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1043 					u64 ino, u32 generation)
1044 {
1045 	struct inode *inode;
1046 
1047 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1048 		return ERR_PTR(-ESTALE);
1049 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1050 		return ERR_PTR(-ESTALE);
1051 
1052 	/* iget isn't really right if the inode is currently unallocated!!
1053 	 *
1054 	 * ext4_read_inode will return a bad_inode if the inode had been
1055 	 * deleted, so we should be safe.
1056 	 *
1057 	 * Currently we don't know the generation for parent directory, so
1058 	 * a generation of 0 means "accept any"
1059 	 */
1060 	inode = ext4_iget(sb, ino);
1061 	if (IS_ERR(inode))
1062 		return ERR_CAST(inode);
1063 	if (generation && inode->i_generation != generation) {
1064 		iput(inode);
1065 		return ERR_PTR(-ESTALE);
1066 	}
1067 
1068 	return inode;
1069 }
1070 
1071 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1072 					int fh_len, int fh_type)
1073 {
1074 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1075 				    ext4_nfs_get_inode);
1076 }
1077 
1078 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1079 					int fh_len, int fh_type)
1080 {
1081 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1082 				    ext4_nfs_get_inode);
1083 }
1084 
1085 /*
1086  * Try to release metadata pages (indirect blocks, directories) which are
1087  * mapped via the block device.  Since these pages could have journal heads
1088  * which would prevent try_to_free_buffers() from freeing them, we must use
1089  * jbd2 layer's try_to_free_buffers() function to release them.
1090  */
1091 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1092 				 gfp_t wait)
1093 {
1094 	journal_t *journal = EXT4_SB(sb)->s_journal;
1095 
1096 	WARN_ON(PageChecked(page));
1097 	if (!page_has_buffers(page))
1098 		return 0;
1099 	if (journal)
1100 		return jbd2_journal_try_to_free_buffers(journal, page,
1101 							wait & ~__GFP_WAIT);
1102 	return try_to_free_buffers(page);
1103 }
1104 
1105 #ifdef CONFIG_QUOTA
1106 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1107 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1108 
1109 static int ext4_write_dquot(struct dquot *dquot);
1110 static int ext4_acquire_dquot(struct dquot *dquot);
1111 static int ext4_release_dquot(struct dquot *dquot);
1112 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1113 static int ext4_write_info(struct super_block *sb, int type);
1114 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1115 			 struct path *path);
1116 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
1117 				 int format_id);
1118 static int ext4_quota_off(struct super_block *sb, int type);
1119 static int ext4_quota_off_sysfile(struct super_block *sb, int type);
1120 static int ext4_quota_on_mount(struct super_block *sb, int type);
1121 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1122 			       size_t len, loff_t off);
1123 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1124 				const char *data, size_t len, loff_t off);
1125 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
1126 			     unsigned int flags);
1127 static int ext4_enable_quotas(struct super_block *sb);
1128 
1129 static const struct dquot_operations ext4_quota_operations = {
1130 	.get_reserved_space = ext4_get_reserved_space,
1131 	.write_dquot	= ext4_write_dquot,
1132 	.acquire_dquot	= ext4_acquire_dquot,
1133 	.release_dquot	= ext4_release_dquot,
1134 	.mark_dirty	= ext4_mark_dquot_dirty,
1135 	.write_info	= ext4_write_info,
1136 	.alloc_dquot	= dquot_alloc,
1137 	.destroy_dquot	= dquot_destroy,
1138 };
1139 
1140 static const struct quotactl_ops ext4_qctl_operations = {
1141 	.quota_on	= ext4_quota_on,
1142 	.quota_off	= ext4_quota_off,
1143 	.quota_sync	= dquot_quota_sync,
1144 	.get_info	= dquot_get_dqinfo,
1145 	.set_info	= dquot_set_dqinfo,
1146 	.get_dqblk	= dquot_get_dqblk,
1147 	.set_dqblk	= dquot_set_dqblk
1148 };
1149 
1150 static const struct quotactl_ops ext4_qctl_sysfile_operations = {
1151 	.quota_on_meta	= ext4_quota_on_sysfile,
1152 	.quota_off	= ext4_quota_off_sysfile,
1153 	.quota_sync	= dquot_quota_sync,
1154 	.get_info	= dquot_get_dqinfo,
1155 	.set_info	= dquot_set_dqinfo,
1156 	.get_dqblk	= dquot_get_dqblk,
1157 	.set_dqblk	= dquot_set_dqblk
1158 };
1159 #endif
1160 
1161 static const struct super_operations ext4_sops = {
1162 	.alloc_inode	= ext4_alloc_inode,
1163 	.destroy_inode	= ext4_destroy_inode,
1164 	.write_inode	= ext4_write_inode,
1165 	.dirty_inode	= ext4_dirty_inode,
1166 	.drop_inode	= ext4_drop_inode,
1167 	.evict_inode	= ext4_evict_inode,
1168 	.put_super	= ext4_put_super,
1169 	.sync_fs	= ext4_sync_fs,
1170 	.freeze_fs	= ext4_freeze,
1171 	.unfreeze_fs	= ext4_unfreeze,
1172 	.statfs		= ext4_statfs,
1173 	.remount_fs	= ext4_remount,
1174 	.show_options	= ext4_show_options,
1175 #ifdef CONFIG_QUOTA
1176 	.quota_read	= ext4_quota_read,
1177 	.quota_write	= ext4_quota_write,
1178 #endif
1179 	.bdev_try_to_free_page = bdev_try_to_free_page,
1180 };
1181 
1182 static const struct super_operations ext4_nojournal_sops = {
1183 	.alloc_inode	= ext4_alloc_inode,
1184 	.destroy_inode	= ext4_destroy_inode,
1185 	.write_inode	= ext4_write_inode,
1186 	.dirty_inode	= ext4_dirty_inode,
1187 	.drop_inode	= ext4_drop_inode,
1188 	.evict_inode	= ext4_evict_inode,
1189 	.put_super	= ext4_put_super,
1190 	.statfs		= ext4_statfs,
1191 	.remount_fs	= ext4_remount,
1192 	.show_options	= ext4_show_options,
1193 #ifdef CONFIG_QUOTA
1194 	.quota_read	= ext4_quota_read,
1195 	.quota_write	= ext4_quota_write,
1196 #endif
1197 	.bdev_try_to_free_page = bdev_try_to_free_page,
1198 };
1199 
1200 static const struct export_operations ext4_export_ops = {
1201 	.fh_to_dentry = ext4_fh_to_dentry,
1202 	.fh_to_parent = ext4_fh_to_parent,
1203 	.get_parent = ext4_get_parent,
1204 };
1205 
1206 enum {
1207 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1208 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1209 	Opt_nouid32, Opt_debug, Opt_removed,
1210 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1211 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload,
1212 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1213 	Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit,
1214 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1215 	Opt_data_err_abort, Opt_data_err_ignore,
1216 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1217 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1218 	Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
1219 	Opt_usrquota, Opt_grpquota, Opt_i_version,
1220 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1221 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1222 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1223 	Opt_dioread_nolock, Opt_dioread_lock,
1224 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
1225 	Opt_max_dir_size_kb,
1226 };
1227 
1228 static const match_table_t tokens = {
1229 	{Opt_bsd_df, "bsddf"},
1230 	{Opt_minix_df, "minixdf"},
1231 	{Opt_grpid, "grpid"},
1232 	{Opt_grpid, "bsdgroups"},
1233 	{Opt_nogrpid, "nogrpid"},
1234 	{Opt_nogrpid, "sysvgroups"},
1235 	{Opt_resgid, "resgid=%u"},
1236 	{Opt_resuid, "resuid=%u"},
1237 	{Opt_sb, "sb=%u"},
1238 	{Opt_err_cont, "errors=continue"},
1239 	{Opt_err_panic, "errors=panic"},
1240 	{Opt_err_ro, "errors=remount-ro"},
1241 	{Opt_nouid32, "nouid32"},
1242 	{Opt_debug, "debug"},
1243 	{Opt_removed, "oldalloc"},
1244 	{Opt_removed, "orlov"},
1245 	{Opt_user_xattr, "user_xattr"},
1246 	{Opt_nouser_xattr, "nouser_xattr"},
1247 	{Opt_acl, "acl"},
1248 	{Opt_noacl, "noacl"},
1249 	{Opt_noload, "norecovery"},
1250 	{Opt_noload, "noload"},
1251 	{Opt_removed, "nobh"},
1252 	{Opt_removed, "bh"},
1253 	{Opt_commit, "commit=%u"},
1254 	{Opt_min_batch_time, "min_batch_time=%u"},
1255 	{Opt_max_batch_time, "max_batch_time=%u"},
1256 	{Opt_journal_dev, "journal_dev=%u"},
1257 	{Opt_journal_checksum, "journal_checksum"},
1258 	{Opt_journal_async_commit, "journal_async_commit"},
1259 	{Opt_abort, "abort"},
1260 	{Opt_data_journal, "data=journal"},
1261 	{Opt_data_ordered, "data=ordered"},
1262 	{Opt_data_writeback, "data=writeback"},
1263 	{Opt_data_err_abort, "data_err=abort"},
1264 	{Opt_data_err_ignore, "data_err=ignore"},
1265 	{Opt_offusrjquota, "usrjquota="},
1266 	{Opt_usrjquota, "usrjquota=%s"},
1267 	{Opt_offgrpjquota, "grpjquota="},
1268 	{Opt_grpjquota, "grpjquota=%s"},
1269 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1270 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1271 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1272 	{Opt_grpquota, "grpquota"},
1273 	{Opt_noquota, "noquota"},
1274 	{Opt_quota, "quota"},
1275 	{Opt_usrquota, "usrquota"},
1276 	{Opt_barrier, "barrier=%u"},
1277 	{Opt_barrier, "barrier"},
1278 	{Opt_nobarrier, "nobarrier"},
1279 	{Opt_i_version, "i_version"},
1280 	{Opt_stripe, "stripe=%u"},
1281 	{Opt_delalloc, "delalloc"},
1282 	{Opt_nodelalloc, "nodelalloc"},
1283 	{Opt_mblk_io_submit, "mblk_io_submit"},
1284 	{Opt_nomblk_io_submit, "nomblk_io_submit"},
1285 	{Opt_block_validity, "block_validity"},
1286 	{Opt_noblock_validity, "noblock_validity"},
1287 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1288 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1289 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1290 	{Opt_auto_da_alloc, "auto_da_alloc"},
1291 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1292 	{Opt_dioread_nolock, "dioread_nolock"},
1293 	{Opt_dioread_lock, "dioread_lock"},
1294 	{Opt_discard, "discard"},
1295 	{Opt_nodiscard, "nodiscard"},
1296 	{Opt_init_itable, "init_itable=%u"},
1297 	{Opt_init_itable, "init_itable"},
1298 	{Opt_noinit_itable, "noinit_itable"},
1299 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
1300 	{Opt_removed, "check=none"},	/* mount option from ext2/3 */
1301 	{Opt_removed, "nocheck"},	/* mount option from ext2/3 */
1302 	{Opt_removed, "reservation"},	/* mount option from ext2/3 */
1303 	{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
1304 	{Opt_removed, "journal=%u"},	/* mount option from ext2/3 */
1305 	{Opt_err, NULL},
1306 };
1307 
1308 static ext4_fsblk_t get_sb_block(void **data)
1309 {
1310 	ext4_fsblk_t	sb_block;
1311 	char		*options = (char *) *data;
1312 
1313 	if (!options || strncmp(options, "sb=", 3) != 0)
1314 		return 1;	/* Default location */
1315 
1316 	options += 3;
1317 	/* TODO: use simple_strtoll with >32bit ext4 */
1318 	sb_block = simple_strtoul(options, &options, 0);
1319 	if (*options && *options != ',') {
1320 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1321 		       (char *) *data);
1322 		return 1;
1323 	}
1324 	if (*options == ',')
1325 		options++;
1326 	*data = (void *) options;
1327 
1328 	return sb_block;
1329 }
1330 
1331 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1332 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1333 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1334 
1335 #ifdef CONFIG_QUOTA
1336 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1337 {
1338 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1339 	char *qname;
1340 
1341 	if (sb_any_quota_loaded(sb) &&
1342 		!sbi->s_qf_names[qtype]) {
1343 		ext4_msg(sb, KERN_ERR,
1344 			"Cannot change journaled "
1345 			"quota options when quota turned on");
1346 		return -1;
1347 	}
1348 	qname = match_strdup(args);
1349 	if (!qname) {
1350 		ext4_msg(sb, KERN_ERR,
1351 			"Not enough memory for storing quotafile name");
1352 		return -1;
1353 	}
1354 	if (sbi->s_qf_names[qtype] &&
1355 		strcmp(sbi->s_qf_names[qtype], qname)) {
1356 		ext4_msg(sb, KERN_ERR,
1357 			"%s quota file already specified", QTYPE2NAME(qtype));
1358 		kfree(qname);
1359 		return -1;
1360 	}
1361 	sbi->s_qf_names[qtype] = qname;
1362 	if (strchr(sbi->s_qf_names[qtype], '/')) {
1363 		ext4_msg(sb, KERN_ERR,
1364 			"quotafile must be on filesystem root");
1365 		kfree(sbi->s_qf_names[qtype]);
1366 		sbi->s_qf_names[qtype] = NULL;
1367 		return -1;
1368 	}
1369 	set_opt(sb, QUOTA);
1370 	return 1;
1371 }
1372 
1373 static int clear_qf_name(struct super_block *sb, int qtype)
1374 {
1375 
1376 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1377 
1378 	if (sb_any_quota_loaded(sb) &&
1379 		sbi->s_qf_names[qtype]) {
1380 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1381 			" when quota turned on");
1382 		return -1;
1383 	}
1384 	/*
1385 	 * The space will be released later when all options are confirmed
1386 	 * to be correct
1387 	 */
1388 	sbi->s_qf_names[qtype] = NULL;
1389 	return 1;
1390 }
1391 #endif
1392 
1393 #define MOPT_SET	0x0001
1394 #define MOPT_CLEAR	0x0002
1395 #define MOPT_NOSUPPORT	0x0004
1396 #define MOPT_EXPLICIT	0x0008
1397 #define MOPT_CLEAR_ERR	0x0010
1398 #define MOPT_GTE0	0x0020
1399 #ifdef CONFIG_QUOTA
1400 #define MOPT_Q		0
1401 #define MOPT_QFMT	0x0040
1402 #else
1403 #define MOPT_Q		MOPT_NOSUPPORT
1404 #define MOPT_QFMT	MOPT_NOSUPPORT
1405 #endif
1406 #define MOPT_DATAJ	0x0080
1407 
1408 static const struct mount_opts {
1409 	int	token;
1410 	int	mount_opt;
1411 	int	flags;
1412 } ext4_mount_opts[] = {
1413 	{Opt_minix_df, EXT4_MOUNT_MINIX_DF, MOPT_SET},
1414 	{Opt_bsd_df, EXT4_MOUNT_MINIX_DF, MOPT_CLEAR},
1415 	{Opt_grpid, EXT4_MOUNT_GRPID, MOPT_SET},
1416 	{Opt_nogrpid, EXT4_MOUNT_GRPID, MOPT_CLEAR},
1417 	{Opt_mblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_SET},
1418 	{Opt_nomblk_io_submit, EXT4_MOUNT_MBLK_IO_SUBMIT, MOPT_CLEAR},
1419 	{Opt_block_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_SET},
1420 	{Opt_noblock_validity, EXT4_MOUNT_BLOCK_VALIDITY, MOPT_CLEAR},
1421 	{Opt_dioread_nolock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_SET},
1422 	{Opt_dioread_lock, EXT4_MOUNT_DIOREAD_NOLOCK, MOPT_CLEAR},
1423 	{Opt_discard, EXT4_MOUNT_DISCARD, MOPT_SET},
1424 	{Opt_nodiscard, EXT4_MOUNT_DISCARD, MOPT_CLEAR},
1425 	{Opt_delalloc, EXT4_MOUNT_DELALLOC, MOPT_SET | MOPT_EXPLICIT},
1426 	{Opt_nodelalloc, EXT4_MOUNT_DELALLOC, MOPT_CLEAR | MOPT_EXPLICIT},
1427 	{Opt_journal_checksum, EXT4_MOUNT_JOURNAL_CHECKSUM, MOPT_SET},
1428 	{Opt_journal_async_commit, (EXT4_MOUNT_JOURNAL_ASYNC_COMMIT |
1429 				    EXT4_MOUNT_JOURNAL_CHECKSUM), MOPT_SET},
1430 	{Opt_noload, EXT4_MOUNT_NOLOAD, MOPT_SET},
1431 	{Opt_err_panic, EXT4_MOUNT_ERRORS_PANIC, MOPT_SET | MOPT_CLEAR_ERR},
1432 	{Opt_err_ro, EXT4_MOUNT_ERRORS_RO, MOPT_SET | MOPT_CLEAR_ERR},
1433 	{Opt_err_cont, EXT4_MOUNT_ERRORS_CONT, MOPT_SET | MOPT_CLEAR_ERR},
1434 	{Opt_data_err_abort, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_SET},
1435 	{Opt_data_err_ignore, EXT4_MOUNT_DATA_ERR_ABORT, MOPT_CLEAR},
1436 	{Opt_barrier, EXT4_MOUNT_BARRIER, MOPT_SET},
1437 	{Opt_nobarrier, EXT4_MOUNT_BARRIER, MOPT_CLEAR},
1438 	{Opt_noauto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_SET},
1439 	{Opt_auto_da_alloc, EXT4_MOUNT_NO_AUTO_DA_ALLOC, MOPT_CLEAR},
1440 	{Opt_noinit_itable, EXT4_MOUNT_INIT_INODE_TABLE, MOPT_CLEAR},
1441 	{Opt_commit, 0, MOPT_GTE0},
1442 	{Opt_max_batch_time, 0, MOPT_GTE0},
1443 	{Opt_min_batch_time, 0, MOPT_GTE0},
1444 	{Opt_inode_readahead_blks, 0, MOPT_GTE0},
1445 	{Opt_init_itable, 0, MOPT_GTE0},
1446 	{Opt_stripe, 0, MOPT_GTE0},
1447 	{Opt_data_journal, EXT4_MOUNT_JOURNAL_DATA, MOPT_DATAJ},
1448 	{Opt_data_ordered, EXT4_MOUNT_ORDERED_DATA, MOPT_DATAJ},
1449 	{Opt_data_writeback, EXT4_MOUNT_WRITEBACK_DATA, MOPT_DATAJ},
1450 #ifdef CONFIG_EXT4_FS_XATTR
1451 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
1452 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
1453 #else
1454 	{Opt_user_xattr, 0, MOPT_NOSUPPORT},
1455 	{Opt_nouser_xattr, 0, MOPT_NOSUPPORT},
1456 #endif
1457 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1458 	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
1459 	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
1460 #else
1461 	{Opt_acl, 0, MOPT_NOSUPPORT},
1462 	{Opt_noacl, 0, MOPT_NOSUPPORT},
1463 #endif
1464 	{Opt_nouid32, EXT4_MOUNT_NO_UID32, MOPT_SET},
1465 	{Opt_debug, EXT4_MOUNT_DEBUG, MOPT_SET},
1466 	{Opt_quota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA, MOPT_SET | MOPT_Q},
1467 	{Opt_usrquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA,
1468 							MOPT_SET | MOPT_Q},
1469 	{Opt_grpquota, EXT4_MOUNT_QUOTA | EXT4_MOUNT_GRPQUOTA,
1470 							MOPT_SET | MOPT_Q},
1471 	{Opt_noquota, (EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
1472 		       EXT4_MOUNT_GRPQUOTA), MOPT_CLEAR | MOPT_Q},
1473 	{Opt_usrjquota, 0, MOPT_Q},
1474 	{Opt_grpjquota, 0, MOPT_Q},
1475 	{Opt_offusrjquota, 0, MOPT_Q},
1476 	{Opt_offgrpjquota, 0, MOPT_Q},
1477 	{Opt_jqfmt_vfsold, QFMT_VFS_OLD, MOPT_QFMT},
1478 	{Opt_jqfmt_vfsv0, QFMT_VFS_V0, MOPT_QFMT},
1479 	{Opt_jqfmt_vfsv1, QFMT_VFS_V1, MOPT_QFMT},
1480 	{Opt_max_dir_size_kb, 0, MOPT_GTE0},
1481 	{Opt_err, 0, 0}
1482 };
1483 
1484 static int handle_mount_opt(struct super_block *sb, char *opt, int token,
1485 			    substring_t *args, unsigned long *journal_devnum,
1486 			    unsigned int *journal_ioprio, int is_remount)
1487 {
1488 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1489 	const struct mount_opts *m;
1490 	kuid_t uid;
1491 	kgid_t gid;
1492 	int arg = 0;
1493 
1494 #ifdef CONFIG_QUOTA
1495 	if (token == Opt_usrjquota)
1496 		return set_qf_name(sb, USRQUOTA, &args[0]);
1497 	else if (token == Opt_grpjquota)
1498 		return set_qf_name(sb, GRPQUOTA, &args[0]);
1499 	else if (token == Opt_offusrjquota)
1500 		return clear_qf_name(sb, USRQUOTA);
1501 	else if (token == Opt_offgrpjquota)
1502 		return clear_qf_name(sb, GRPQUOTA);
1503 #endif
1504 	if (args->from && match_int(args, &arg))
1505 		return -1;
1506 	switch (token) {
1507 	case Opt_noacl:
1508 	case Opt_nouser_xattr:
1509 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
1510 		break;
1511 	case Opt_sb:
1512 		return 1;	/* handled by get_sb_block() */
1513 	case Opt_removed:
1514 		ext4_msg(sb, KERN_WARNING,
1515 			 "Ignoring removed %s option", opt);
1516 		return 1;
1517 	case Opt_resuid:
1518 		uid = make_kuid(current_user_ns(), arg);
1519 		if (!uid_valid(uid)) {
1520 			ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
1521 			return -1;
1522 		}
1523 		sbi->s_resuid = uid;
1524 		return 1;
1525 	case Opt_resgid:
1526 		gid = make_kgid(current_user_ns(), arg);
1527 		if (!gid_valid(gid)) {
1528 			ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
1529 			return -1;
1530 		}
1531 		sbi->s_resgid = gid;
1532 		return 1;
1533 	case Opt_abort:
1534 		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1535 		return 1;
1536 	case Opt_i_version:
1537 		sb->s_flags |= MS_I_VERSION;
1538 		return 1;
1539 	case Opt_journal_dev:
1540 		if (is_remount) {
1541 			ext4_msg(sb, KERN_ERR,
1542 				 "Cannot specify journal on remount");
1543 			return -1;
1544 		}
1545 		*journal_devnum = arg;
1546 		return 1;
1547 	case Opt_journal_ioprio:
1548 		if (arg < 0 || arg > 7)
1549 			return -1;
1550 		*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
1551 		return 1;
1552 	}
1553 
1554 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1555 		if (token != m->token)
1556 			continue;
1557 		if (args->from && (m->flags & MOPT_GTE0) && (arg < 0))
1558 			return -1;
1559 		if (m->flags & MOPT_EXPLICIT)
1560 			set_opt2(sb, EXPLICIT_DELALLOC);
1561 		if (m->flags & MOPT_CLEAR_ERR)
1562 			clear_opt(sb, ERRORS_MASK);
1563 		if (token == Opt_noquota && sb_any_quota_loaded(sb)) {
1564 			ext4_msg(sb, KERN_ERR, "Cannot change quota "
1565 				 "options when quota turned on");
1566 			return -1;
1567 		}
1568 
1569 		if (m->flags & MOPT_NOSUPPORT) {
1570 			ext4_msg(sb, KERN_ERR, "%s option not supported", opt);
1571 		} else if (token == Opt_commit) {
1572 			if (arg == 0)
1573 				arg = JBD2_DEFAULT_MAX_COMMIT_AGE;
1574 			sbi->s_commit_interval = HZ * arg;
1575 		} else if (token == Opt_max_batch_time) {
1576 			if (arg == 0)
1577 				arg = EXT4_DEF_MAX_BATCH_TIME;
1578 			sbi->s_max_batch_time = arg;
1579 		} else if (token == Opt_min_batch_time) {
1580 			sbi->s_min_batch_time = arg;
1581 		} else if (token == Opt_inode_readahead_blks) {
1582 			if (arg > (1 << 30))
1583 				return -1;
1584 			if (arg && !is_power_of_2(arg)) {
1585 				ext4_msg(sb, KERN_ERR,
1586 					 "EXT4-fs: inode_readahead_blks"
1587 					 " must be a power of 2");
1588 				return -1;
1589 			}
1590 			sbi->s_inode_readahead_blks = arg;
1591 		} else if (token == Opt_init_itable) {
1592 			set_opt(sb, INIT_INODE_TABLE);
1593 			if (!args->from)
1594 				arg = EXT4_DEF_LI_WAIT_MULT;
1595 			sbi->s_li_wait_mult = arg;
1596 		} else if (token == Opt_max_dir_size_kb) {
1597 			sbi->s_max_dir_size_kb = arg;
1598 		} else if (token == Opt_stripe) {
1599 			sbi->s_stripe = arg;
1600 		} else if (m->flags & MOPT_DATAJ) {
1601 			if (is_remount) {
1602 				if (!sbi->s_journal)
1603 					ext4_msg(sb, KERN_WARNING, "Remounting file system with no journal so ignoring journalled data option");
1604 				else if (test_opt(sb, DATA_FLAGS) !=
1605 					 m->mount_opt) {
1606 					ext4_msg(sb, KERN_ERR,
1607 					 "Cannot change data mode on remount");
1608 					return -1;
1609 				}
1610 			} else {
1611 				clear_opt(sb, DATA_FLAGS);
1612 				sbi->s_mount_opt |= m->mount_opt;
1613 			}
1614 #ifdef CONFIG_QUOTA
1615 		} else if (m->flags & MOPT_QFMT) {
1616 			if (sb_any_quota_loaded(sb) &&
1617 			    sbi->s_jquota_fmt != m->mount_opt) {
1618 				ext4_msg(sb, KERN_ERR, "Cannot "
1619 					 "change journaled quota options "
1620 					 "when quota turned on");
1621 				return -1;
1622 			}
1623 			sbi->s_jquota_fmt = m->mount_opt;
1624 #endif
1625 		} else {
1626 			if (!args->from)
1627 				arg = 1;
1628 			if (m->flags & MOPT_CLEAR)
1629 				arg = !arg;
1630 			else if (unlikely(!(m->flags & MOPT_SET))) {
1631 				ext4_msg(sb, KERN_WARNING,
1632 					 "buggy handling of option %s", opt);
1633 				WARN_ON(1);
1634 				return -1;
1635 			}
1636 			if (arg != 0)
1637 				sbi->s_mount_opt |= m->mount_opt;
1638 			else
1639 				sbi->s_mount_opt &= ~m->mount_opt;
1640 		}
1641 		return 1;
1642 	}
1643 	ext4_msg(sb, KERN_ERR, "Unrecognized mount option \"%s\" "
1644 		 "or missing value", opt);
1645 	return -1;
1646 }
1647 
1648 static int parse_options(char *options, struct super_block *sb,
1649 			 unsigned long *journal_devnum,
1650 			 unsigned int *journal_ioprio,
1651 			 int is_remount)
1652 {
1653 #ifdef CONFIG_QUOTA
1654 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1655 #endif
1656 	char *p;
1657 	substring_t args[MAX_OPT_ARGS];
1658 	int token;
1659 
1660 	if (!options)
1661 		return 1;
1662 
1663 	while ((p = strsep(&options, ",")) != NULL) {
1664 		if (!*p)
1665 			continue;
1666 		/*
1667 		 * Initialize args struct so we know whether arg was
1668 		 * found; some options take optional arguments.
1669 		 */
1670 		args[0].to = args[0].from = NULL;
1671 		token = match_token(p, tokens, args);
1672 		if (handle_mount_opt(sb, p, token, args, journal_devnum,
1673 				     journal_ioprio, is_remount) < 0)
1674 			return 0;
1675 	}
1676 #ifdef CONFIG_QUOTA
1677 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1678 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1679 			clear_opt(sb, USRQUOTA);
1680 
1681 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1682 			clear_opt(sb, GRPQUOTA);
1683 
1684 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1685 			ext4_msg(sb, KERN_ERR, "old and new quota "
1686 					"format mixing");
1687 			return 0;
1688 		}
1689 
1690 		if (!sbi->s_jquota_fmt) {
1691 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1692 					"not specified");
1693 			return 0;
1694 		}
1695 	} else {
1696 		if (sbi->s_jquota_fmt) {
1697 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1698 					"specified with no journaling "
1699 					"enabled");
1700 			return 0;
1701 		}
1702 	}
1703 #endif
1704 	return 1;
1705 }
1706 
1707 static inline void ext4_show_quota_options(struct seq_file *seq,
1708 					   struct super_block *sb)
1709 {
1710 #if defined(CONFIG_QUOTA)
1711 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1712 
1713 	if (sbi->s_jquota_fmt) {
1714 		char *fmtname = "";
1715 
1716 		switch (sbi->s_jquota_fmt) {
1717 		case QFMT_VFS_OLD:
1718 			fmtname = "vfsold";
1719 			break;
1720 		case QFMT_VFS_V0:
1721 			fmtname = "vfsv0";
1722 			break;
1723 		case QFMT_VFS_V1:
1724 			fmtname = "vfsv1";
1725 			break;
1726 		}
1727 		seq_printf(seq, ",jqfmt=%s", fmtname);
1728 	}
1729 
1730 	if (sbi->s_qf_names[USRQUOTA])
1731 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
1732 
1733 	if (sbi->s_qf_names[GRPQUOTA])
1734 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
1735 
1736 	if (test_opt(sb, USRQUOTA))
1737 		seq_puts(seq, ",usrquota");
1738 
1739 	if (test_opt(sb, GRPQUOTA))
1740 		seq_puts(seq, ",grpquota");
1741 #endif
1742 }
1743 
1744 static const char *token2str(int token)
1745 {
1746 	const struct match_token *t;
1747 
1748 	for (t = tokens; t->token != Opt_err; t++)
1749 		if (t->token == token && !strchr(t->pattern, '='))
1750 			break;
1751 	return t->pattern;
1752 }
1753 
1754 /*
1755  * Show an option if
1756  *  - it's set to a non-default value OR
1757  *  - if the per-sb default is different from the global default
1758  */
1759 static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
1760 			      int nodefs)
1761 {
1762 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1763 	struct ext4_super_block *es = sbi->s_es;
1764 	int def_errors, def_mount_opt = nodefs ? 0 : sbi->s_def_mount_opt;
1765 	const struct mount_opts *m;
1766 	char sep = nodefs ? '\n' : ',';
1767 
1768 #define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
1769 #define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
1770 
1771 	if (sbi->s_sb_block != 1)
1772 		SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
1773 
1774 	for (m = ext4_mount_opts; m->token != Opt_err; m++) {
1775 		int want_set = m->flags & MOPT_SET;
1776 		if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) ||
1777 		    (m->flags & MOPT_CLEAR_ERR))
1778 			continue;
1779 		if (!(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt)))
1780 			continue; /* skip if same as the default */
1781 		if ((want_set &&
1782 		     (sbi->s_mount_opt & m->mount_opt) != m->mount_opt) ||
1783 		    (!want_set && (sbi->s_mount_opt & m->mount_opt)))
1784 			continue; /* select Opt_noFoo vs Opt_Foo */
1785 		SEQ_OPTS_PRINT("%s", token2str(m->token));
1786 	}
1787 
1788 	if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
1789 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
1790 		SEQ_OPTS_PRINT("resuid=%u",
1791 				from_kuid_munged(&init_user_ns, sbi->s_resuid));
1792 	if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
1793 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
1794 		SEQ_OPTS_PRINT("resgid=%u",
1795 				from_kgid_munged(&init_user_ns, sbi->s_resgid));
1796 	def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
1797 	if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
1798 		SEQ_OPTS_PUTS("errors=remount-ro");
1799 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
1800 		SEQ_OPTS_PUTS("errors=continue");
1801 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
1802 		SEQ_OPTS_PUTS("errors=panic");
1803 	if (nodefs || sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ)
1804 		SEQ_OPTS_PRINT("commit=%lu", sbi->s_commit_interval / HZ);
1805 	if (nodefs || sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME)
1806 		SEQ_OPTS_PRINT("min_batch_time=%u", sbi->s_min_batch_time);
1807 	if (nodefs || sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME)
1808 		SEQ_OPTS_PRINT("max_batch_time=%u", sbi->s_max_batch_time);
1809 	if (sb->s_flags & MS_I_VERSION)
1810 		SEQ_OPTS_PUTS("i_version");
1811 	if (nodefs || sbi->s_stripe)
1812 		SEQ_OPTS_PRINT("stripe=%lu", sbi->s_stripe);
1813 	if (EXT4_MOUNT_DATA_FLAGS & (sbi->s_mount_opt ^ def_mount_opt)) {
1814 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1815 			SEQ_OPTS_PUTS("data=journal");
1816 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1817 			SEQ_OPTS_PUTS("data=ordered");
1818 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1819 			SEQ_OPTS_PUTS("data=writeback");
1820 	}
1821 	if (nodefs ||
1822 	    sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1823 		SEQ_OPTS_PRINT("inode_readahead_blks=%u",
1824 			       sbi->s_inode_readahead_blks);
1825 
1826 	if (nodefs || (test_opt(sb, INIT_INODE_TABLE) &&
1827 		       (sbi->s_li_wait_mult != EXT4_DEF_LI_WAIT_MULT)))
1828 		SEQ_OPTS_PRINT("init_itable=%u", sbi->s_li_wait_mult);
1829 	if (nodefs || sbi->s_max_dir_size_kb)
1830 		SEQ_OPTS_PRINT("max_dir_size_kb=%u", sbi->s_max_dir_size_kb);
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 int ext4_alloc_flex_bg_array(struct super_block *sb, ext4_group_t ngroup)
1923 {
1924 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1925 	struct flex_groups *new_groups;
1926 	int size;
1927 
1928 	if (!sbi->s_log_groups_per_flex)
1929 		return 0;
1930 
1931 	size = ext4_flex_group(sbi, ngroup - 1) + 1;
1932 	if (size <= sbi->s_flex_groups_allocated)
1933 		return 0;
1934 
1935 	size = roundup_pow_of_two(size * sizeof(struct flex_groups));
1936 	new_groups = ext4_kvzalloc(size, GFP_KERNEL);
1937 	if (!new_groups) {
1938 		ext4_msg(sb, KERN_ERR, "not enough memory for %d flex groups",
1939 			 size / (int) sizeof(struct flex_groups));
1940 		return -ENOMEM;
1941 	}
1942 
1943 	if (sbi->s_flex_groups) {
1944 		memcpy(new_groups, sbi->s_flex_groups,
1945 		       (sbi->s_flex_groups_allocated *
1946 			sizeof(struct flex_groups)));
1947 		ext4_kvfree(sbi->s_flex_groups);
1948 	}
1949 	sbi->s_flex_groups = new_groups;
1950 	sbi->s_flex_groups_allocated = size / sizeof(struct flex_groups);
1951 	return 0;
1952 }
1953 
1954 static int ext4_fill_flex_info(struct super_block *sb)
1955 {
1956 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1957 	struct ext4_group_desc *gdp = NULL;
1958 	ext4_group_t flex_group;
1959 	unsigned int groups_per_flex = 0;
1960 	int i, err;
1961 
1962 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1963 	if (sbi->s_log_groups_per_flex < 1 || sbi->s_log_groups_per_flex > 31) {
1964 		sbi->s_log_groups_per_flex = 0;
1965 		return 1;
1966 	}
1967 	groups_per_flex = 1U << sbi->s_log_groups_per_flex;
1968 
1969 	err = ext4_alloc_flex_bg_array(sb, sbi->s_groups_count);
1970 	if (err)
1971 		goto failed;
1972 
1973 	for (i = 0; i < sbi->s_groups_count; i++) {
1974 		gdp = ext4_get_group_desc(sb, i, NULL);
1975 
1976 		flex_group = ext4_flex_group(sbi, i);
1977 		atomic_add(ext4_free_inodes_count(sb, gdp),
1978 			   &sbi->s_flex_groups[flex_group].free_inodes);
1979 		atomic_add(ext4_free_group_clusters(sb, gdp),
1980 			   &sbi->s_flex_groups[flex_group].free_clusters);
1981 		atomic_add(ext4_used_dirs_count(sb, gdp),
1982 			   &sbi->s_flex_groups[flex_group].used_dirs);
1983 	}
1984 
1985 	return 1;
1986 failed:
1987 	return 0;
1988 }
1989 
1990 static __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1991 				   struct ext4_group_desc *gdp)
1992 {
1993 	int offset;
1994 	__u16 crc = 0;
1995 	__le32 le_group = cpu_to_le32(block_group);
1996 
1997 	if ((sbi->s_es->s_feature_ro_compat &
1998 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))) {
1999 		/* Use new metadata_csum algorithm */
2000 		__u16 old_csum;
2001 		__u32 csum32;
2002 
2003 		old_csum = gdp->bg_checksum;
2004 		gdp->bg_checksum = 0;
2005 		csum32 = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&le_group,
2006 				     sizeof(le_group));
2007 		csum32 = ext4_chksum(sbi, csum32, (__u8 *)gdp,
2008 				     sbi->s_desc_size);
2009 		gdp->bg_checksum = old_csum;
2010 
2011 		crc = csum32 & 0xFFFF;
2012 		goto out;
2013 	}
2014 
2015 	/* old crc16 code */
2016 	offset = offsetof(struct ext4_group_desc, bg_checksum);
2017 
2018 	crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
2019 	crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
2020 	crc = crc16(crc, (__u8 *)gdp, offset);
2021 	offset += sizeof(gdp->bg_checksum); /* skip checksum */
2022 	/* for checksum of struct ext4_group_desc do the rest...*/
2023 	if ((sbi->s_es->s_feature_incompat &
2024 	     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
2025 	    offset < le16_to_cpu(sbi->s_es->s_desc_size))
2026 		crc = crc16(crc, (__u8 *)gdp + offset,
2027 			    le16_to_cpu(sbi->s_es->s_desc_size) -
2028 				offset);
2029 
2030 out:
2031 	return cpu_to_le16(crc);
2032 }
2033 
2034 int ext4_group_desc_csum_verify(struct super_block *sb, __u32 block_group,
2035 				struct ext4_group_desc *gdp)
2036 {
2037 	if (ext4_has_group_desc_csum(sb) &&
2038 	    (gdp->bg_checksum != ext4_group_desc_csum(EXT4_SB(sb),
2039 						      block_group, gdp)))
2040 		return 0;
2041 
2042 	return 1;
2043 }
2044 
2045 void ext4_group_desc_csum_set(struct super_block *sb, __u32 block_group,
2046 			      struct ext4_group_desc *gdp)
2047 {
2048 	if (!ext4_has_group_desc_csum(sb))
2049 		return;
2050 	gdp->bg_checksum = ext4_group_desc_csum(EXT4_SB(sb), block_group, gdp);
2051 }
2052 
2053 /* Called at mount-time, super-block is locked */
2054 static int ext4_check_descriptors(struct super_block *sb,
2055 				  ext4_group_t *first_not_zeroed)
2056 {
2057 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2058 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2059 	ext4_fsblk_t last_block;
2060 	ext4_fsblk_t block_bitmap;
2061 	ext4_fsblk_t inode_bitmap;
2062 	ext4_fsblk_t inode_table;
2063 	int flexbg_flag = 0;
2064 	ext4_group_t i, grp = sbi->s_groups_count;
2065 
2066 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2067 		flexbg_flag = 1;
2068 
2069 	ext4_debug("Checking group descriptors");
2070 
2071 	for (i = 0; i < sbi->s_groups_count; i++) {
2072 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2073 
2074 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2075 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2076 		else
2077 			last_block = first_block +
2078 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2079 
2080 		if ((grp == sbi->s_groups_count) &&
2081 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2082 			grp = i;
2083 
2084 		block_bitmap = ext4_block_bitmap(sb, gdp);
2085 		if (block_bitmap < first_block || block_bitmap > last_block) {
2086 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2087 			       "Block bitmap for group %u not in group "
2088 			       "(block %llu)!", i, block_bitmap);
2089 			return 0;
2090 		}
2091 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2092 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2093 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2094 			       "Inode bitmap for group %u not in group "
2095 			       "(block %llu)!", i, inode_bitmap);
2096 			return 0;
2097 		}
2098 		inode_table = ext4_inode_table(sb, gdp);
2099 		if (inode_table < first_block ||
2100 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2101 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2102 			       "Inode table for group %u not in group "
2103 			       "(block %llu)!", i, inode_table);
2104 			return 0;
2105 		}
2106 		ext4_lock_group(sb, i);
2107 		if (!ext4_group_desc_csum_verify(sb, i, gdp)) {
2108 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2109 				 "Checksum for group %u failed (%u!=%u)",
2110 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2111 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2112 			if (!(sb->s_flags & MS_RDONLY)) {
2113 				ext4_unlock_group(sb, i);
2114 				return 0;
2115 			}
2116 		}
2117 		ext4_unlock_group(sb, i);
2118 		if (!flexbg_flag)
2119 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2120 	}
2121 	if (NULL != first_not_zeroed)
2122 		*first_not_zeroed = grp;
2123 
2124 	ext4_free_blocks_count_set(sbi->s_es,
2125 				   EXT4_C2B(sbi, ext4_count_free_clusters(sb)));
2126 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2127 	return 1;
2128 }
2129 
2130 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2131  * the superblock) which were deleted from all directories, but held open by
2132  * a process at the time of a crash.  We walk the list and try to delete these
2133  * inodes at recovery time (only with a read-write filesystem).
2134  *
2135  * In order to keep the orphan inode chain consistent during traversal (in
2136  * case of crash during recovery), we link each inode into the superblock
2137  * orphan list_head and handle it the same way as an inode deletion during
2138  * normal operation (which journals the operations for us).
2139  *
2140  * We only do an iget() and an iput() on each inode, which is very safe if we
2141  * accidentally point at an in-use or already deleted inode.  The worst that
2142  * can happen in this case is that we get a "bit already cleared" message from
2143  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2144  * e2fsck was run on this filesystem, and it must have already done the orphan
2145  * inode cleanup for us, so we can safely abort without any further action.
2146  */
2147 static void ext4_orphan_cleanup(struct super_block *sb,
2148 				struct ext4_super_block *es)
2149 {
2150 	unsigned int s_flags = sb->s_flags;
2151 	int nr_orphans = 0, nr_truncates = 0;
2152 #ifdef CONFIG_QUOTA
2153 	int i;
2154 #endif
2155 	if (!es->s_last_orphan) {
2156 		jbd_debug(4, "no orphan inodes to clean up\n");
2157 		return;
2158 	}
2159 
2160 	if (bdev_read_only(sb->s_bdev)) {
2161 		ext4_msg(sb, KERN_ERR, "write access "
2162 			"unavailable, skipping orphan cleanup");
2163 		return;
2164 	}
2165 
2166 	/* Check if feature set would not allow a r/w mount */
2167 	if (!ext4_feature_set_ok(sb, 0)) {
2168 		ext4_msg(sb, KERN_INFO, "Skipping orphan cleanup due to "
2169 			 "unknown ROCOMPAT features");
2170 		return;
2171 	}
2172 
2173 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2174 		/* don't clear list on RO mount w/ errors */
2175 		if (es->s_last_orphan && !(s_flags & MS_RDONLY)) {
2176 			jbd_debug(1, "Errors on filesystem, "
2177 				  "clearing orphan list.\n");
2178 			es->s_last_orphan = 0;
2179 		}
2180 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2181 		return;
2182 	}
2183 
2184 	if (s_flags & MS_RDONLY) {
2185 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2186 		sb->s_flags &= ~MS_RDONLY;
2187 	}
2188 #ifdef CONFIG_QUOTA
2189 	/* Needed for iput() to work correctly and not trash data */
2190 	sb->s_flags |= MS_ACTIVE;
2191 	/* Turn on quotas so that they are updated correctly */
2192 	for (i = 0; i < MAXQUOTAS; i++) {
2193 		if (EXT4_SB(sb)->s_qf_names[i]) {
2194 			int ret = ext4_quota_on_mount(sb, i);
2195 			if (ret < 0)
2196 				ext4_msg(sb, KERN_ERR,
2197 					"Cannot turn on journaled "
2198 					"quota: error %d", ret);
2199 		}
2200 	}
2201 #endif
2202 
2203 	while (es->s_last_orphan) {
2204 		struct inode *inode;
2205 
2206 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2207 		if (IS_ERR(inode)) {
2208 			es->s_last_orphan = 0;
2209 			break;
2210 		}
2211 
2212 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2213 		dquot_initialize(inode);
2214 		if (inode->i_nlink) {
2215 			ext4_msg(sb, KERN_DEBUG,
2216 				"%s: truncating inode %lu to %lld bytes",
2217 				__func__, inode->i_ino, inode->i_size);
2218 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2219 				  inode->i_ino, inode->i_size);
2220 			ext4_truncate(inode);
2221 			nr_truncates++;
2222 		} else {
2223 			ext4_msg(sb, KERN_DEBUG,
2224 				"%s: deleting unreferenced inode %lu",
2225 				__func__, inode->i_ino);
2226 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2227 				  inode->i_ino);
2228 			nr_orphans++;
2229 		}
2230 		iput(inode);  /* The delete magic happens here! */
2231 	}
2232 
2233 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2234 
2235 	if (nr_orphans)
2236 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2237 		       PLURAL(nr_orphans));
2238 	if (nr_truncates)
2239 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2240 		       PLURAL(nr_truncates));
2241 #ifdef CONFIG_QUOTA
2242 	/* Turn quotas off */
2243 	for (i = 0; i < MAXQUOTAS; i++) {
2244 		if (sb_dqopt(sb)->files[i])
2245 			dquot_quota_off(sb, i);
2246 	}
2247 #endif
2248 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2249 }
2250 
2251 /*
2252  * Maximal extent format file size.
2253  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2254  * extent format containers, within a sector_t, and within i_blocks
2255  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2256  * so that won't be a limiting factor.
2257  *
2258  * However there is other limiting factor. We do store extents in the form
2259  * of starting block and length, hence the resulting length of the extent
2260  * covering maximum file size must fit into on-disk format containers as
2261  * well. Given that length is always by 1 unit bigger than max unit (because
2262  * we count 0 as well) we have to lower the s_maxbytes by one fs block.
2263  *
2264  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2265  */
2266 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2267 {
2268 	loff_t res;
2269 	loff_t upper_limit = MAX_LFS_FILESIZE;
2270 
2271 	/* small i_blocks in vfs inode? */
2272 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2273 		/*
2274 		 * CONFIG_LBDAF is not enabled implies the inode
2275 		 * i_block represent total blocks in 512 bytes
2276 		 * 32 == size of vfs inode i_blocks * 8
2277 		 */
2278 		upper_limit = (1LL << 32) - 1;
2279 
2280 		/* total blocks in file system block size */
2281 		upper_limit >>= (blkbits - 9);
2282 		upper_limit <<= blkbits;
2283 	}
2284 
2285 	/*
2286 	 * 32-bit extent-start container, ee_block. We lower the maxbytes
2287 	 * by one fs block, so ee_len can cover the extent of maximum file
2288 	 * size
2289 	 */
2290 	res = (1LL << 32) - 1;
2291 	res <<= blkbits;
2292 
2293 	/* Sanity check against vm- & vfs- imposed limits */
2294 	if (res > upper_limit)
2295 		res = upper_limit;
2296 
2297 	return res;
2298 }
2299 
2300 /*
2301  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2302  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2303  * We need to be 1 filesystem block less than the 2^48 sector limit.
2304  */
2305 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2306 {
2307 	loff_t res = EXT4_NDIR_BLOCKS;
2308 	int meta_blocks;
2309 	loff_t upper_limit;
2310 	/* This is calculated to be the largest file size for a dense, block
2311 	 * mapped file such that the file's total number of 512-byte sectors,
2312 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2313 	 *
2314 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2315 	 * number of 512-byte sectors of the file.
2316 	 */
2317 
2318 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2319 		/*
2320 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2321 		 * the inode i_block field represents total file blocks in
2322 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2323 		 */
2324 		upper_limit = (1LL << 32) - 1;
2325 
2326 		/* total blocks in file system block size */
2327 		upper_limit >>= (bits - 9);
2328 
2329 	} else {
2330 		/*
2331 		 * We use 48 bit ext4_inode i_blocks
2332 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2333 		 * represent total number of blocks in
2334 		 * file system block size
2335 		 */
2336 		upper_limit = (1LL << 48) - 1;
2337 
2338 	}
2339 
2340 	/* indirect blocks */
2341 	meta_blocks = 1;
2342 	/* double indirect blocks */
2343 	meta_blocks += 1 + (1LL << (bits-2));
2344 	/* tripple indirect blocks */
2345 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2346 
2347 	upper_limit -= meta_blocks;
2348 	upper_limit <<= bits;
2349 
2350 	res += 1LL << (bits-2);
2351 	res += 1LL << (2*(bits-2));
2352 	res += 1LL << (3*(bits-2));
2353 	res <<= bits;
2354 	if (res > upper_limit)
2355 		res = upper_limit;
2356 
2357 	if (res > MAX_LFS_FILESIZE)
2358 		res = MAX_LFS_FILESIZE;
2359 
2360 	return res;
2361 }
2362 
2363 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2364 				   ext4_fsblk_t logical_sb_block, int nr)
2365 {
2366 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2367 	ext4_group_t bg, first_meta_bg;
2368 	int has_super = 0;
2369 
2370 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2371 
2372 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2373 	    nr < first_meta_bg)
2374 		return logical_sb_block + nr + 1;
2375 	bg = sbi->s_desc_per_block * nr;
2376 	if (ext4_bg_has_super(sb, bg))
2377 		has_super = 1;
2378 
2379 	return (has_super + ext4_group_first_block_no(sb, bg));
2380 }
2381 
2382 /**
2383  * ext4_get_stripe_size: Get the stripe size.
2384  * @sbi: In memory super block info
2385  *
2386  * If we have specified it via mount option, then
2387  * use the mount option value. If the value specified at mount time is
2388  * greater than the blocks per group use the super block value.
2389  * If the super block value is greater than blocks per group return 0.
2390  * Allocator needs it be less than blocks per group.
2391  *
2392  */
2393 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2394 {
2395 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2396 	unsigned long stripe_width =
2397 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2398 	int ret;
2399 
2400 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2401 		ret = sbi->s_stripe;
2402 	else if (stripe_width <= sbi->s_blocks_per_group)
2403 		ret = stripe_width;
2404 	else if (stride <= sbi->s_blocks_per_group)
2405 		ret = stride;
2406 	else
2407 		ret = 0;
2408 
2409 	/*
2410 	 * If the stripe width is 1, this makes no sense and
2411 	 * we set it to 0 to turn off stripe handling code.
2412 	 */
2413 	if (ret <= 1)
2414 		ret = 0;
2415 
2416 	return ret;
2417 }
2418 
2419 /* sysfs supprt */
2420 
2421 struct ext4_attr {
2422 	struct attribute attr;
2423 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2424 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2425 			 const char *, size_t);
2426 	int offset;
2427 };
2428 
2429 static int parse_strtoul(const char *buf,
2430 		unsigned long max, unsigned long *value)
2431 {
2432 	char *endp;
2433 
2434 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2435 	endp = skip_spaces(endp);
2436 	if (*endp || *value > max)
2437 		return -EINVAL;
2438 
2439 	return 0;
2440 }
2441 
2442 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2443 					      struct ext4_sb_info *sbi,
2444 					      char *buf)
2445 {
2446 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2447 		(s64) EXT4_C2B(sbi,
2448 			percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
2449 }
2450 
2451 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2452 					 struct ext4_sb_info *sbi, char *buf)
2453 {
2454 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2455 
2456 	if (!sb->s_bdev->bd_part)
2457 		return snprintf(buf, PAGE_SIZE, "0\n");
2458 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2459 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2460 			 sbi->s_sectors_written_start) >> 1);
2461 }
2462 
2463 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2464 					  struct ext4_sb_info *sbi, char *buf)
2465 {
2466 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2467 
2468 	if (!sb->s_bdev->bd_part)
2469 		return snprintf(buf, PAGE_SIZE, "0\n");
2470 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2471 			(unsigned long long)(sbi->s_kbytes_written +
2472 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2473 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2474 }
2475 
2476 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2477 					  struct ext4_sb_info *sbi,
2478 					  const char *buf, size_t count)
2479 {
2480 	unsigned long t;
2481 
2482 	if (parse_strtoul(buf, 0x40000000, &t))
2483 		return -EINVAL;
2484 
2485 	if (t && !is_power_of_2(t))
2486 		return -EINVAL;
2487 
2488 	sbi->s_inode_readahead_blks = t;
2489 	return count;
2490 }
2491 
2492 static ssize_t sbi_ui_show(struct ext4_attr *a,
2493 			   struct ext4_sb_info *sbi, char *buf)
2494 {
2495 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2496 
2497 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2498 }
2499 
2500 static ssize_t sbi_ui_store(struct ext4_attr *a,
2501 			    struct ext4_sb_info *sbi,
2502 			    const char *buf, size_t count)
2503 {
2504 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2505 	unsigned long t;
2506 
2507 	if (parse_strtoul(buf, 0xffffffff, &t))
2508 		return -EINVAL;
2509 	*ui = t;
2510 	return count;
2511 }
2512 
2513 static ssize_t trigger_test_error(struct ext4_attr *a,
2514 				  struct ext4_sb_info *sbi,
2515 				  const char *buf, size_t count)
2516 {
2517 	int len = count;
2518 
2519 	if (!capable(CAP_SYS_ADMIN))
2520 		return -EPERM;
2521 
2522 	if (len && buf[len-1] == '\n')
2523 		len--;
2524 
2525 	if (len)
2526 		ext4_error(sbi->s_sb, "%.*s", len, buf);
2527 	return count;
2528 }
2529 
2530 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2531 static struct ext4_attr ext4_attr_##_name = {			\
2532 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2533 	.show	= _show,					\
2534 	.store	= _store,					\
2535 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2536 }
2537 #define EXT4_ATTR(name, mode, show, store) \
2538 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2539 
2540 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2541 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2542 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2543 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2544 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2545 #define ATTR_LIST(name) &ext4_attr_##name.attr
2546 
2547 EXT4_RO_ATTR(delayed_allocation_blocks);
2548 EXT4_RO_ATTR(session_write_kbytes);
2549 EXT4_RO_ATTR(lifetime_write_kbytes);
2550 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2551 		 inode_readahead_blks_store, s_inode_readahead_blks);
2552 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2553 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2554 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2555 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2556 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2557 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2558 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2559 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2560 EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
2561 EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
2562 
2563 static struct attribute *ext4_attrs[] = {
2564 	ATTR_LIST(delayed_allocation_blocks),
2565 	ATTR_LIST(session_write_kbytes),
2566 	ATTR_LIST(lifetime_write_kbytes),
2567 	ATTR_LIST(inode_readahead_blks),
2568 	ATTR_LIST(inode_goal),
2569 	ATTR_LIST(mb_stats),
2570 	ATTR_LIST(mb_max_to_scan),
2571 	ATTR_LIST(mb_min_to_scan),
2572 	ATTR_LIST(mb_order2_req),
2573 	ATTR_LIST(mb_stream_req),
2574 	ATTR_LIST(mb_group_prealloc),
2575 	ATTR_LIST(max_writeback_mb_bump),
2576 	ATTR_LIST(extent_max_zeroout_kb),
2577 	ATTR_LIST(trigger_fs_error),
2578 	NULL,
2579 };
2580 
2581 /* Features this copy of ext4 supports */
2582 EXT4_INFO_ATTR(lazy_itable_init);
2583 EXT4_INFO_ATTR(batched_discard);
2584 EXT4_INFO_ATTR(meta_bg_resize);
2585 
2586 static struct attribute *ext4_feat_attrs[] = {
2587 	ATTR_LIST(lazy_itable_init),
2588 	ATTR_LIST(batched_discard),
2589 	ATTR_LIST(meta_bg_resize),
2590 	NULL,
2591 };
2592 
2593 static ssize_t ext4_attr_show(struct kobject *kobj,
2594 			      struct attribute *attr, char *buf)
2595 {
2596 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2597 						s_kobj);
2598 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2599 
2600 	return a->show ? a->show(a, sbi, buf) : 0;
2601 }
2602 
2603 static ssize_t ext4_attr_store(struct kobject *kobj,
2604 			       struct attribute *attr,
2605 			       const char *buf, size_t len)
2606 {
2607 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2608 						s_kobj);
2609 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2610 
2611 	return a->store ? a->store(a, sbi, buf, len) : 0;
2612 }
2613 
2614 static void ext4_sb_release(struct kobject *kobj)
2615 {
2616 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2617 						s_kobj);
2618 	complete(&sbi->s_kobj_unregister);
2619 }
2620 
2621 static const struct sysfs_ops ext4_attr_ops = {
2622 	.show	= ext4_attr_show,
2623 	.store	= ext4_attr_store,
2624 };
2625 
2626 static struct kobj_type ext4_ktype = {
2627 	.default_attrs	= ext4_attrs,
2628 	.sysfs_ops	= &ext4_attr_ops,
2629 	.release	= ext4_sb_release,
2630 };
2631 
2632 static void ext4_feat_release(struct kobject *kobj)
2633 {
2634 	complete(&ext4_feat->f_kobj_unregister);
2635 }
2636 
2637 static struct kobj_type ext4_feat_ktype = {
2638 	.default_attrs	= ext4_feat_attrs,
2639 	.sysfs_ops	= &ext4_attr_ops,
2640 	.release	= ext4_feat_release,
2641 };
2642 
2643 /*
2644  * Check whether this filesystem can be mounted based on
2645  * the features present and the RDONLY/RDWR mount requested.
2646  * Returns 1 if this filesystem can be mounted as requested,
2647  * 0 if it cannot be.
2648  */
2649 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2650 {
2651 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2652 		ext4_msg(sb, KERN_ERR,
2653 			"Couldn't mount because of "
2654 			"unsupported optional features (%x)",
2655 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2656 			~EXT4_FEATURE_INCOMPAT_SUPP));
2657 		return 0;
2658 	}
2659 
2660 	if (readonly)
2661 		return 1;
2662 
2663 	/* Check that feature set is OK for a read-write mount */
2664 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2665 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2666 			 "unsupported optional features (%x)",
2667 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2668 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2669 		return 0;
2670 	}
2671 	/*
2672 	 * Large file size enabled file system can only be mounted
2673 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2674 	 */
2675 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2676 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2677 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2678 				 "cannot be mounted RDWR without "
2679 				 "CONFIG_LBDAF");
2680 			return 0;
2681 		}
2682 	}
2683 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC) &&
2684 	    !EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2685 		ext4_msg(sb, KERN_ERR,
2686 			 "Can't support bigalloc feature without "
2687 			 "extents feature\n");
2688 		return 0;
2689 	}
2690 
2691 #ifndef CONFIG_QUOTA
2692 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
2693 	    !readonly) {
2694 		ext4_msg(sb, KERN_ERR,
2695 			 "Filesystem with quota feature cannot be mounted RDWR "
2696 			 "without CONFIG_QUOTA");
2697 		return 0;
2698 	}
2699 #endif  /* CONFIG_QUOTA */
2700 	return 1;
2701 }
2702 
2703 /*
2704  * This function is called once a day if we have errors logged
2705  * on the file system
2706  */
2707 static void print_daily_error_info(unsigned long arg)
2708 {
2709 	struct super_block *sb = (struct super_block *) arg;
2710 	struct ext4_sb_info *sbi;
2711 	struct ext4_super_block *es;
2712 
2713 	sbi = EXT4_SB(sb);
2714 	es = sbi->s_es;
2715 
2716 	if (es->s_error_count)
2717 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2718 			 le32_to_cpu(es->s_error_count));
2719 	if (es->s_first_error_time) {
2720 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2721 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2722 		       (int) sizeof(es->s_first_error_func),
2723 		       es->s_first_error_func,
2724 		       le32_to_cpu(es->s_first_error_line));
2725 		if (es->s_first_error_ino)
2726 			printk(": inode %u",
2727 			       le32_to_cpu(es->s_first_error_ino));
2728 		if (es->s_first_error_block)
2729 			printk(": block %llu", (unsigned long long)
2730 			       le64_to_cpu(es->s_first_error_block));
2731 		printk("\n");
2732 	}
2733 	if (es->s_last_error_time) {
2734 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2735 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2736 		       (int) sizeof(es->s_last_error_func),
2737 		       es->s_last_error_func,
2738 		       le32_to_cpu(es->s_last_error_line));
2739 		if (es->s_last_error_ino)
2740 			printk(": inode %u",
2741 			       le32_to_cpu(es->s_last_error_ino));
2742 		if (es->s_last_error_block)
2743 			printk(": block %llu", (unsigned long long)
2744 			       le64_to_cpu(es->s_last_error_block));
2745 		printk("\n");
2746 	}
2747 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2748 }
2749 
2750 /* Find next suitable group and run ext4_init_inode_table */
2751 static int ext4_run_li_request(struct ext4_li_request *elr)
2752 {
2753 	struct ext4_group_desc *gdp = NULL;
2754 	ext4_group_t group, ngroups;
2755 	struct super_block *sb;
2756 	unsigned long timeout = 0;
2757 	int ret = 0;
2758 
2759 	sb = elr->lr_super;
2760 	ngroups = EXT4_SB(sb)->s_groups_count;
2761 
2762 	sb_start_write(sb);
2763 	for (group = elr->lr_next_group; group < ngroups; group++) {
2764 		gdp = ext4_get_group_desc(sb, group, NULL);
2765 		if (!gdp) {
2766 			ret = 1;
2767 			break;
2768 		}
2769 
2770 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2771 			break;
2772 	}
2773 
2774 	if (group == ngroups)
2775 		ret = 1;
2776 
2777 	if (!ret) {
2778 		timeout = jiffies;
2779 		ret = ext4_init_inode_table(sb, group,
2780 					    elr->lr_timeout ? 0 : 1);
2781 		if (elr->lr_timeout == 0) {
2782 			timeout = (jiffies - timeout) *
2783 				  elr->lr_sbi->s_li_wait_mult;
2784 			elr->lr_timeout = timeout;
2785 		}
2786 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2787 		elr->lr_next_group = group + 1;
2788 	}
2789 	sb_end_write(sb);
2790 
2791 	return ret;
2792 }
2793 
2794 /*
2795  * Remove lr_request from the list_request and free the
2796  * request structure. Should be called with li_list_mtx held
2797  */
2798 static void ext4_remove_li_request(struct ext4_li_request *elr)
2799 {
2800 	struct ext4_sb_info *sbi;
2801 
2802 	if (!elr)
2803 		return;
2804 
2805 	sbi = elr->lr_sbi;
2806 
2807 	list_del(&elr->lr_request);
2808 	sbi->s_li_request = NULL;
2809 	kfree(elr);
2810 }
2811 
2812 static void ext4_unregister_li_request(struct super_block *sb)
2813 {
2814 	mutex_lock(&ext4_li_mtx);
2815 	if (!ext4_li_info) {
2816 		mutex_unlock(&ext4_li_mtx);
2817 		return;
2818 	}
2819 
2820 	mutex_lock(&ext4_li_info->li_list_mtx);
2821 	ext4_remove_li_request(EXT4_SB(sb)->s_li_request);
2822 	mutex_unlock(&ext4_li_info->li_list_mtx);
2823 	mutex_unlock(&ext4_li_mtx);
2824 }
2825 
2826 static struct task_struct *ext4_lazyinit_task;
2827 
2828 /*
2829  * This is the function where ext4lazyinit thread lives. It walks
2830  * through the request list searching for next scheduled filesystem.
2831  * When such a fs is found, run the lazy initialization request
2832  * (ext4_rn_li_request) and keep track of the time spend in this
2833  * function. Based on that time we compute next schedule time of
2834  * the request. When walking through the list is complete, compute
2835  * next waking time and put itself into sleep.
2836  */
2837 static int ext4_lazyinit_thread(void *arg)
2838 {
2839 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2840 	struct list_head *pos, *n;
2841 	struct ext4_li_request *elr;
2842 	unsigned long next_wakeup, cur;
2843 
2844 	BUG_ON(NULL == eli);
2845 
2846 cont_thread:
2847 	while (true) {
2848 		next_wakeup = MAX_JIFFY_OFFSET;
2849 
2850 		mutex_lock(&eli->li_list_mtx);
2851 		if (list_empty(&eli->li_request_list)) {
2852 			mutex_unlock(&eli->li_list_mtx);
2853 			goto exit_thread;
2854 		}
2855 
2856 		list_for_each_safe(pos, n, &eli->li_request_list) {
2857 			elr = list_entry(pos, struct ext4_li_request,
2858 					 lr_request);
2859 
2860 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2861 				if (ext4_run_li_request(elr) != 0) {
2862 					/* error, remove the lazy_init job */
2863 					ext4_remove_li_request(elr);
2864 					continue;
2865 				}
2866 			}
2867 
2868 			if (time_before(elr->lr_next_sched, next_wakeup))
2869 				next_wakeup = elr->lr_next_sched;
2870 		}
2871 		mutex_unlock(&eli->li_list_mtx);
2872 
2873 		try_to_freeze();
2874 
2875 		cur = jiffies;
2876 		if ((time_after_eq(cur, next_wakeup)) ||
2877 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2878 			cond_resched();
2879 			continue;
2880 		}
2881 
2882 		schedule_timeout_interruptible(next_wakeup - cur);
2883 
2884 		if (kthread_should_stop()) {
2885 			ext4_clear_request_list();
2886 			goto exit_thread;
2887 		}
2888 	}
2889 
2890 exit_thread:
2891 	/*
2892 	 * It looks like the request list is empty, but we need
2893 	 * to check it under the li_list_mtx lock, to prevent any
2894 	 * additions into it, and of course we should lock ext4_li_mtx
2895 	 * to atomically free the list and ext4_li_info, because at
2896 	 * this point another ext4 filesystem could be registering
2897 	 * new one.
2898 	 */
2899 	mutex_lock(&ext4_li_mtx);
2900 	mutex_lock(&eli->li_list_mtx);
2901 	if (!list_empty(&eli->li_request_list)) {
2902 		mutex_unlock(&eli->li_list_mtx);
2903 		mutex_unlock(&ext4_li_mtx);
2904 		goto cont_thread;
2905 	}
2906 	mutex_unlock(&eli->li_list_mtx);
2907 	kfree(ext4_li_info);
2908 	ext4_li_info = NULL;
2909 	mutex_unlock(&ext4_li_mtx);
2910 
2911 	return 0;
2912 }
2913 
2914 static void ext4_clear_request_list(void)
2915 {
2916 	struct list_head *pos, *n;
2917 	struct ext4_li_request *elr;
2918 
2919 	mutex_lock(&ext4_li_info->li_list_mtx);
2920 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2921 		elr = list_entry(pos, struct ext4_li_request,
2922 				 lr_request);
2923 		ext4_remove_li_request(elr);
2924 	}
2925 	mutex_unlock(&ext4_li_info->li_list_mtx);
2926 }
2927 
2928 static int ext4_run_lazyinit_thread(void)
2929 {
2930 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2931 					 ext4_li_info, "ext4lazyinit");
2932 	if (IS_ERR(ext4_lazyinit_task)) {
2933 		int err = PTR_ERR(ext4_lazyinit_task);
2934 		ext4_clear_request_list();
2935 		kfree(ext4_li_info);
2936 		ext4_li_info = NULL;
2937 		printk(KERN_CRIT "EXT4-fs: error %d creating inode table "
2938 				 "initialization thread\n",
2939 				 err);
2940 		return err;
2941 	}
2942 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2943 	return 0;
2944 }
2945 
2946 /*
2947  * Check whether it make sense to run itable init. thread or not.
2948  * If there is at least one uninitialized inode table, return
2949  * corresponding group number, else the loop goes through all
2950  * groups and return total number of groups.
2951  */
2952 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2953 {
2954 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2955 	struct ext4_group_desc *gdp = NULL;
2956 
2957 	for (group = 0; group < ngroups; group++) {
2958 		gdp = ext4_get_group_desc(sb, group, NULL);
2959 		if (!gdp)
2960 			continue;
2961 
2962 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2963 			break;
2964 	}
2965 
2966 	return group;
2967 }
2968 
2969 static int ext4_li_info_new(void)
2970 {
2971 	struct ext4_lazy_init *eli = NULL;
2972 
2973 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2974 	if (!eli)
2975 		return -ENOMEM;
2976 
2977 	INIT_LIST_HEAD(&eli->li_request_list);
2978 	mutex_init(&eli->li_list_mtx);
2979 
2980 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2981 
2982 	ext4_li_info = eli;
2983 
2984 	return 0;
2985 }
2986 
2987 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2988 					    ext4_group_t start)
2989 {
2990 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2991 	struct ext4_li_request *elr;
2992 	unsigned long rnd;
2993 
2994 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2995 	if (!elr)
2996 		return NULL;
2997 
2998 	elr->lr_super = sb;
2999 	elr->lr_sbi = sbi;
3000 	elr->lr_next_group = start;
3001 
3002 	/*
3003 	 * Randomize first schedule time of the request to
3004 	 * spread the inode table initialization requests
3005 	 * better.
3006 	 */
3007 	get_random_bytes(&rnd, sizeof(rnd));
3008 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
3009 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
3010 
3011 	return elr;
3012 }
3013 
3014 static int ext4_register_li_request(struct super_block *sb,
3015 				    ext4_group_t first_not_zeroed)
3016 {
3017 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3018 	struct ext4_li_request *elr;
3019 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
3020 	int ret = 0;
3021 
3022 	if (sbi->s_li_request != NULL) {
3023 		/*
3024 		 * Reset timeout so it can be computed again, because
3025 		 * s_li_wait_mult might have changed.
3026 		 */
3027 		sbi->s_li_request->lr_timeout = 0;
3028 		return 0;
3029 	}
3030 
3031 	if (first_not_zeroed == ngroups ||
3032 	    (sb->s_flags & MS_RDONLY) ||
3033 	    !test_opt(sb, INIT_INODE_TABLE))
3034 		return 0;
3035 
3036 	elr = ext4_li_request_new(sb, first_not_zeroed);
3037 	if (!elr)
3038 		return -ENOMEM;
3039 
3040 	mutex_lock(&ext4_li_mtx);
3041 
3042 	if (NULL == ext4_li_info) {
3043 		ret = ext4_li_info_new();
3044 		if (ret)
3045 			goto out;
3046 	}
3047 
3048 	mutex_lock(&ext4_li_info->li_list_mtx);
3049 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
3050 	mutex_unlock(&ext4_li_info->li_list_mtx);
3051 
3052 	sbi->s_li_request = elr;
3053 	/*
3054 	 * set elr to NULL here since it has been inserted to
3055 	 * the request_list and the removal and free of it is
3056 	 * handled by ext4_clear_request_list from now on.
3057 	 */
3058 	elr = NULL;
3059 
3060 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
3061 		ret = ext4_run_lazyinit_thread();
3062 		if (ret)
3063 			goto out;
3064 	}
3065 out:
3066 	mutex_unlock(&ext4_li_mtx);
3067 	if (ret)
3068 		kfree(elr);
3069 	return ret;
3070 }
3071 
3072 /*
3073  * We do not need to lock anything since this is called on
3074  * module unload.
3075  */
3076 static void ext4_destroy_lazyinit_thread(void)
3077 {
3078 	/*
3079 	 * If thread exited earlier
3080 	 * there's nothing to be done.
3081 	 */
3082 	if (!ext4_li_info || !ext4_lazyinit_task)
3083 		return;
3084 
3085 	kthread_stop(ext4_lazyinit_task);
3086 }
3087 
3088 static int set_journal_csum_feature_set(struct super_block *sb)
3089 {
3090 	int ret = 1;
3091 	int compat, incompat;
3092 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3093 
3094 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3095 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3096 		/* journal checksum v2 */
3097 		compat = 0;
3098 		incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
3099 	} else {
3100 		/* journal checksum v1 */
3101 		compat = JBD2_FEATURE_COMPAT_CHECKSUM;
3102 		incompat = 0;
3103 	}
3104 
3105 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3106 		ret = jbd2_journal_set_features(sbi->s_journal,
3107 				compat, 0,
3108 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3109 				incompat);
3110 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3111 		ret = jbd2_journal_set_features(sbi->s_journal,
3112 				compat, 0,
3113 				incompat);
3114 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3115 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3116 	} else {
3117 		jbd2_journal_clear_features(sbi->s_journal,
3118 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3119 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
3120 				JBD2_FEATURE_INCOMPAT_CSUM_V2);
3121 	}
3122 
3123 	return ret;
3124 }
3125 
3126 /*
3127  * Note: calculating the overhead so we can be compatible with
3128  * historical BSD practice is quite difficult in the face of
3129  * clusters/bigalloc.  This is because multiple metadata blocks from
3130  * different block group can end up in the same allocation cluster.
3131  * Calculating the exact overhead in the face of clustered allocation
3132  * requires either O(all block bitmaps) in memory or O(number of block
3133  * groups**2) in time.  We will still calculate the superblock for
3134  * older file systems --- and if we come across with a bigalloc file
3135  * system with zero in s_overhead_clusters the estimate will be close to
3136  * correct especially for very large cluster sizes --- but for newer
3137  * file systems, it's better to calculate this figure once at mkfs
3138  * time, and store it in the superblock.  If the superblock value is
3139  * present (even for non-bigalloc file systems), we will use it.
3140  */
3141 static int count_overhead(struct super_block *sb, ext4_group_t grp,
3142 			  char *buf)
3143 {
3144 	struct ext4_sb_info	*sbi = EXT4_SB(sb);
3145 	struct ext4_group_desc	*gdp;
3146 	ext4_fsblk_t		first_block, last_block, b;
3147 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
3148 	int			s, j, count = 0;
3149 
3150 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
3151 		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
3152 			sbi->s_itb_per_group + 2);
3153 
3154 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
3155 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
3156 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
3157 	for (i = 0; i < ngroups; i++) {
3158 		gdp = ext4_get_group_desc(sb, i, NULL);
3159 		b = ext4_block_bitmap(sb, gdp);
3160 		if (b >= first_block && b <= last_block) {
3161 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3162 			count++;
3163 		}
3164 		b = ext4_inode_bitmap(sb, gdp);
3165 		if (b >= first_block && b <= last_block) {
3166 			ext4_set_bit(EXT4_B2C(sbi, b - first_block), buf);
3167 			count++;
3168 		}
3169 		b = ext4_inode_table(sb, gdp);
3170 		if (b >= first_block && b + sbi->s_itb_per_group <= last_block)
3171 			for (j = 0; j < sbi->s_itb_per_group; j++, b++) {
3172 				int c = EXT4_B2C(sbi, b - first_block);
3173 				ext4_set_bit(c, buf);
3174 				count++;
3175 			}
3176 		if (i != grp)
3177 			continue;
3178 		s = 0;
3179 		if (ext4_bg_has_super(sb, grp)) {
3180 			ext4_set_bit(s++, buf);
3181 			count++;
3182 		}
3183 		for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) {
3184 			ext4_set_bit(EXT4_B2C(sbi, s++), buf);
3185 			count++;
3186 		}
3187 	}
3188 	if (!count)
3189 		return 0;
3190 	return EXT4_CLUSTERS_PER_GROUP(sb) -
3191 		ext4_count_free(buf, EXT4_CLUSTERS_PER_GROUP(sb) / 8);
3192 }
3193 
3194 /*
3195  * Compute the overhead and stash it in sbi->s_overhead
3196  */
3197 int ext4_calculate_overhead(struct super_block *sb)
3198 {
3199 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3200 	struct ext4_super_block *es = sbi->s_es;
3201 	ext4_group_t i, ngroups = ext4_get_groups_count(sb);
3202 	ext4_fsblk_t overhead = 0;
3203 	char *buf = (char *) get_zeroed_page(GFP_KERNEL);
3204 
3205 	memset(buf, 0, PAGE_SIZE);
3206 	if (!buf)
3207 		return -ENOMEM;
3208 
3209 	/*
3210 	 * Compute the overhead (FS structures).  This is constant
3211 	 * for a given filesystem unless the number of block groups
3212 	 * changes so we cache the previous value until it does.
3213 	 */
3214 
3215 	/*
3216 	 * All of the blocks before first_data_block are overhead
3217 	 */
3218 	overhead = EXT4_B2C(sbi, le32_to_cpu(es->s_first_data_block));
3219 
3220 	/*
3221 	 * Add the overhead found in each block group
3222 	 */
3223 	for (i = 0; i < ngroups; i++) {
3224 		int blks;
3225 
3226 		blks = count_overhead(sb, i, buf);
3227 		overhead += blks;
3228 		if (blks)
3229 			memset(buf, 0, PAGE_SIZE);
3230 		cond_resched();
3231 	}
3232 	sbi->s_overhead = overhead;
3233 	smp_wmb();
3234 	free_page((unsigned long) buf);
3235 	return 0;
3236 }
3237 
3238 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3239 {
3240 	char *orig_data = kstrdup(data, GFP_KERNEL);
3241 	struct buffer_head *bh;
3242 	struct ext4_super_block *es = NULL;
3243 	struct ext4_sb_info *sbi;
3244 	ext4_fsblk_t block;
3245 	ext4_fsblk_t sb_block = get_sb_block(&data);
3246 	ext4_fsblk_t logical_sb_block;
3247 	unsigned long offset = 0;
3248 	unsigned long journal_devnum = 0;
3249 	unsigned long def_mount_opts;
3250 	struct inode *root;
3251 	char *cp;
3252 	const char *descr;
3253 	int ret = -ENOMEM;
3254 	int blocksize, clustersize;
3255 	unsigned int db_count;
3256 	unsigned int i;
3257 	int needs_recovery, has_huge_files, has_bigalloc;
3258 	__u64 blocks_count;
3259 	int err;
3260 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3261 	ext4_group_t first_not_zeroed;
3262 
3263 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3264 	if (!sbi)
3265 		goto out_free_orig;
3266 
3267 	sbi->s_blockgroup_lock =
3268 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3269 	if (!sbi->s_blockgroup_lock) {
3270 		kfree(sbi);
3271 		goto out_free_orig;
3272 	}
3273 	sb->s_fs_info = sbi;
3274 	sbi->s_sb = sb;
3275 	sbi->s_mount_opt = 0;
3276 	sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
3277 	sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
3278 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3279 	sbi->s_sb_block = sb_block;
3280 	if (sb->s_bdev->bd_part)
3281 		sbi->s_sectors_written_start =
3282 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3283 
3284 	/* Cleanup superblock name */
3285 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3286 		*cp = '!';
3287 
3288 	ret = -EINVAL;
3289 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3290 	if (!blocksize) {
3291 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3292 		goto out_fail;
3293 	}
3294 
3295 	/*
3296 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3297 	 * block sizes.  We need to calculate the offset from buffer start.
3298 	 */
3299 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3300 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3301 		offset = do_div(logical_sb_block, blocksize);
3302 	} else {
3303 		logical_sb_block = sb_block;
3304 	}
3305 
3306 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3307 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3308 		goto out_fail;
3309 	}
3310 	/*
3311 	 * Note: s_es must be initialized as soon as possible because
3312 	 *       some ext4 macro-instructions depend on its value
3313 	 */
3314 	es = (struct ext4_super_block *) (bh->b_data + offset);
3315 	sbi->s_es = es;
3316 	sb->s_magic = le16_to_cpu(es->s_magic);
3317 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3318 		goto cantfind_ext4;
3319 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3320 
3321 	/* Warn if metadata_csum and gdt_csum are both set. */
3322 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3323 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
3324 	    EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
3325 		ext4_warning(sb, KERN_INFO "metadata_csum and uninit_bg are "
3326 			     "redundant flags; please run fsck.");
3327 
3328 	/* Check for a known checksum algorithm */
3329 	if (!ext4_verify_csum_type(sb, es)) {
3330 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3331 			 "unknown checksum algorithm.");
3332 		silent = 1;
3333 		goto cantfind_ext4;
3334 	}
3335 
3336 	/* Load the checksum driver */
3337 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3338 				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3339 		sbi->s_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
3340 		if (IS_ERR(sbi->s_chksum_driver)) {
3341 			ext4_msg(sb, KERN_ERR, "Cannot load crc32c driver.");
3342 			ret = PTR_ERR(sbi->s_chksum_driver);
3343 			sbi->s_chksum_driver = NULL;
3344 			goto failed_mount;
3345 		}
3346 	}
3347 
3348 	/* Check superblock checksum */
3349 	if (!ext4_superblock_csum_verify(sb, es)) {
3350 		ext4_msg(sb, KERN_ERR, "VFS: Found ext4 filesystem with "
3351 			 "invalid superblock checksum.  Run e2fsck?");
3352 		silent = 1;
3353 		goto cantfind_ext4;
3354 	}
3355 
3356 	/* Precompute checksum seed for all metadata */
3357 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3358 			EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
3359 		sbi->s_csum_seed = ext4_chksum(sbi, ~0, es->s_uuid,
3360 					       sizeof(es->s_uuid));
3361 
3362 	/* Set defaults before we parse the mount options */
3363 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3364 	set_opt(sb, INIT_INODE_TABLE);
3365 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3366 		set_opt(sb, DEBUG);
3367 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS)
3368 		set_opt(sb, GRPID);
3369 	if (def_mount_opts & EXT4_DEFM_UID16)
3370 		set_opt(sb, NO_UID32);
3371 	/* xattr user namespace & acls are now defaulted on */
3372 #ifdef CONFIG_EXT4_FS_XATTR
3373 	set_opt(sb, XATTR_USER);
3374 #endif
3375 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3376 	set_opt(sb, POSIX_ACL);
3377 #endif
3378 	set_opt(sb, MBLK_IO_SUBMIT);
3379 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3380 		set_opt(sb, JOURNAL_DATA);
3381 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3382 		set_opt(sb, ORDERED_DATA);
3383 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3384 		set_opt(sb, WRITEBACK_DATA);
3385 
3386 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3387 		set_opt(sb, ERRORS_PANIC);
3388 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3389 		set_opt(sb, ERRORS_CONT);
3390 	else
3391 		set_opt(sb, ERRORS_RO);
3392 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3393 		set_opt(sb, BLOCK_VALIDITY);
3394 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3395 		set_opt(sb, DISCARD);
3396 
3397 	sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
3398 	sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
3399 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3400 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3401 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3402 
3403 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3404 		set_opt(sb, BARRIER);
3405 
3406 	/*
3407 	 * enable delayed allocation by default
3408 	 * Use -o nodelalloc to turn it off
3409 	 */
3410 	if (!IS_EXT3_SB(sb) && !IS_EXT2_SB(sb) &&
3411 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3412 		set_opt(sb, DELALLOC);
3413 
3414 	/*
3415 	 * set default s_li_wait_mult for lazyinit, for the case there is
3416 	 * no mount option specified.
3417 	 */
3418 	sbi->s_li_wait_mult = EXT4_DEF_LI_WAIT_MULT;
3419 
3420 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3421 			   &journal_devnum, &journal_ioprio, 0)) {
3422 		ext4_msg(sb, KERN_WARNING,
3423 			 "failed to parse options in superblock: %s",
3424 			 sbi->s_es->s_mount_opts);
3425 	}
3426 	sbi->s_def_mount_opt = sbi->s_mount_opt;
3427 	if (!parse_options((char *) data, sb, &journal_devnum,
3428 			   &journal_ioprio, 0))
3429 		goto failed_mount;
3430 
3431 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3432 		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting "
3433 			    "with data=journal disables delayed "
3434 			    "allocation and O_DIRECT support!\n");
3435 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
3436 			ext4_msg(sb, KERN_ERR, "can't mount with "
3437 				 "both data=journal and delalloc");
3438 			goto failed_mount;
3439 		}
3440 		if (test_opt(sb, DIOREAD_NOLOCK)) {
3441 			ext4_msg(sb, KERN_ERR, "can't mount with "
3442 				 "both data=journal and delalloc");
3443 			goto failed_mount;
3444 		}
3445 		if (test_opt(sb, DELALLOC))
3446 			clear_opt(sb, DELALLOC);
3447 	}
3448 
3449 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3450 	if (test_opt(sb, DIOREAD_NOLOCK)) {
3451 		if (blocksize < PAGE_SIZE) {
3452 			ext4_msg(sb, KERN_ERR, "can't mount with "
3453 				 "dioread_nolock if block size != PAGE_SIZE");
3454 			goto failed_mount;
3455 		}
3456 	}
3457 
3458 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3459 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3460 
3461 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3462 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3463 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3464 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3465 		ext4_msg(sb, KERN_WARNING,
3466 		       "feature flags set on rev 0 fs, "
3467 		       "running e2fsck is recommended");
3468 
3469 	if (IS_EXT2_SB(sb)) {
3470 		if (ext2_feature_set_ok(sb))
3471 			ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
3472 				 "using the ext4 subsystem");
3473 		else {
3474 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext2 due "
3475 				 "to feature incompatibilities");
3476 			goto failed_mount;
3477 		}
3478 	}
3479 
3480 	if (IS_EXT3_SB(sb)) {
3481 		if (ext3_feature_set_ok(sb))
3482 			ext4_msg(sb, KERN_INFO, "mounting ext3 file system "
3483 				 "using the ext4 subsystem");
3484 		else {
3485 			ext4_msg(sb, KERN_ERR, "couldn't mount as ext3 due "
3486 				 "to feature incompatibilities");
3487 			goto failed_mount;
3488 		}
3489 	}
3490 
3491 	/*
3492 	 * Check feature flags regardless of the revision level, since we
3493 	 * previously didn't change the revision level when setting the flags,
3494 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3495 	 */
3496 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3497 		goto failed_mount;
3498 
3499 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3500 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3501 		ext4_msg(sb, KERN_ERR,
3502 		       "Unsupported filesystem blocksize %d", blocksize);
3503 		goto failed_mount;
3504 	}
3505 
3506 	if (sb->s_blocksize != blocksize) {
3507 		/* Validate the filesystem blocksize */
3508 		if (!sb_set_blocksize(sb, blocksize)) {
3509 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3510 					blocksize);
3511 			goto failed_mount;
3512 		}
3513 
3514 		brelse(bh);
3515 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3516 		offset = do_div(logical_sb_block, blocksize);
3517 		bh = sb_bread(sb, logical_sb_block);
3518 		if (!bh) {
3519 			ext4_msg(sb, KERN_ERR,
3520 			       "Can't read superblock on 2nd try");
3521 			goto failed_mount;
3522 		}
3523 		es = (struct ext4_super_block *)(bh->b_data + offset);
3524 		sbi->s_es = es;
3525 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3526 			ext4_msg(sb, KERN_ERR,
3527 			       "Magic mismatch, very weird!");
3528 			goto failed_mount;
3529 		}
3530 	}
3531 
3532 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3533 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3534 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3535 						      has_huge_files);
3536 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3537 
3538 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3539 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3540 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3541 	} else {
3542 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3543 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3544 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3545 		    (!is_power_of_2(sbi->s_inode_size)) ||
3546 		    (sbi->s_inode_size > blocksize)) {
3547 			ext4_msg(sb, KERN_ERR,
3548 			       "unsupported inode size: %d",
3549 			       sbi->s_inode_size);
3550 			goto failed_mount;
3551 		}
3552 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3553 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3554 	}
3555 
3556 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3557 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3558 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3559 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3560 		    !is_power_of_2(sbi->s_desc_size)) {
3561 			ext4_msg(sb, KERN_ERR,
3562 			       "unsupported descriptor size %lu",
3563 			       sbi->s_desc_size);
3564 			goto failed_mount;
3565 		}
3566 	} else
3567 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3568 
3569 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3570 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3571 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3572 		goto cantfind_ext4;
3573 
3574 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3575 	if (sbi->s_inodes_per_block == 0)
3576 		goto cantfind_ext4;
3577 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3578 					sbi->s_inodes_per_block;
3579 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3580 	sbi->s_sbh = bh;
3581 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3582 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3583 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3584 
3585 	for (i = 0; i < 4; i++)
3586 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3587 	sbi->s_def_hash_version = es->s_def_hash_version;
3588 	i = le32_to_cpu(es->s_flags);
3589 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3590 		sbi->s_hash_unsigned = 3;
3591 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3592 #ifdef __CHAR_UNSIGNED__
3593 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3594 		sbi->s_hash_unsigned = 3;
3595 #else
3596 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3597 #endif
3598 	}
3599 
3600 	/* Handle clustersize */
3601 	clustersize = BLOCK_SIZE << le32_to_cpu(es->s_log_cluster_size);
3602 	has_bigalloc = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3603 				EXT4_FEATURE_RO_COMPAT_BIGALLOC);
3604 	if (has_bigalloc) {
3605 		if (clustersize < blocksize) {
3606 			ext4_msg(sb, KERN_ERR,
3607 				 "cluster size (%d) smaller than "
3608 				 "block size (%d)", clustersize, blocksize);
3609 			goto failed_mount;
3610 		}
3611 		sbi->s_cluster_bits = le32_to_cpu(es->s_log_cluster_size) -
3612 			le32_to_cpu(es->s_log_block_size);
3613 		sbi->s_clusters_per_group =
3614 			le32_to_cpu(es->s_clusters_per_group);
3615 		if (sbi->s_clusters_per_group > blocksize * 8) {
3616 			ext4_msg(sb, KERN_ERR,
3617 				 "#clusters per group too big: %lu",
3618 				 sbi->s_clusters_per_group);
3619 			goto failed_mount;
3620 		}
3621 		if (sbi->s_blocks_per_group !=
3622 		    (sbi->s_clusters_per_group * (clustersize / blocksize))) {
3623 			ext4_msg(sb, KERN_ERR, "blocks per group (%lu) and "
3624 				 "clusters per group (%lu) inconsistent",
3625 				 sbi->s_blocks_per_group,
3626 				 sbi->s_clusters_per_group);
3627 			goto failed_mount;
3628 		}
3629 	} else {
3630 		if (clustersize != blocksize) {
3631 			ext4_warning(sb, "fragment/cluster size (%d) != "
3632 				     "block size (%d)", clustersize,
3633 				     blocksize);
3634 			clustersize = blocksize;
3635 		}
3636 		if (sbi->s_blocks_per_group > blocksize * 8) {
3637 			ext4_msg(sb, KERN_ERR,
3638 				 "#blocks per group too big: %lu",
3639 				 sbi->s_blocks_per_group);
3640 			goto failed_mount;
3641 		}
3642 		sbi->s_clusters_per_group = sbi->s_blocks_per_group;
3643 		sbi->s_cluster_bits = 0;
3644 	}
3645 	sbi->s_cluster_ratio = clustersize / blocksize;
3646 
3647 	if (sbi->s_inodes_per_group > blocksize * 8) {
3648 		ext4_msg(sb, KERN_ERR,
3649 		       "#inodes per group too big: %lu",
3650 		       sbi->s_inodes_per_group);
3651 		goto failed_mount;
3652 	}
3653 
3654 	/*
3655 	 * Test whether we have more sectors than will fit in sector_t,
3656 	 * and whether the max offset is addressable by the page cache.
3657 	 */
3658 	err = generic_check_addressable(sb->s_blocksize_bits,
3659 					ext4_blocks_count(es));
3660 	if (err) {
3661 		ext4_msg(sb, KERN_ERR, "filesystem"
3662 			 " too large to mount safely on this system");
3663 		if (sizeof(sector_t) < 8)
3664 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3665 		ret = err;
3666 		goto failed_mount;
3667 	}
3668 
3669 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3670 		goto cantfind_ext4;
3671 
3672 	/* check blocks count against device size */
3673 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3674 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3675 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3676 		       "exceeds size of device (%llu blocks)",
3677 		       ext4_blocks_count(es), blocks_count);
3678 		goto failed_mount;
3679 	}
3680 
3681 	/*
3682 	 * It makes no sense for the first data block to be beyond the end
3683 	 * of the filesystem.
3684 	 */
3685 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3686 		ext4_msg(sb, KERN_WARNING, "bad geometry: first data "
3687 			 "block %u is beyond end of filesystem (%llu)",
3688 			 le32_to_cpu(es->s_first_data_block),
3689 			 ext4_blocks_count(es));
3690 		goto failed_mount;
3691 	}
3692 	blocks_count = (ext4_blocks_count(es) -
3693 			le32_to_cpu(es->s_first_data_block) +
3694 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3695 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3696 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3697 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3698 		       "(block count %llu, first data block %u, "
3699 		       "blocks per group %lu)", sbi->s_groups_count,
3700 		       ext4_blocks_count(es),
3701 		       le32_to_cpu(es->s_first_data_block),
3702 		       EXT4_BLOCKS_PER_GROUP(sb));
3703 		goto failed_mount;
3704 	}
3705 	sbi->s_groups_count = blocks_count;
3706 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3707 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3708 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3709 		   EXT4_DESC_PER_BLOCK(sb);
3710 	sbi->s_group_desc = ext4_kvmalloc(db_count *
3711 					  sizeof(struct buffer_head *),
3712 					  GFP_KERNEL);
3713 	if (sbi->s_group_desc == NULL) {
3714 		ext4_msg(sb, KERN_ERR, "not enough memory");
3715 		ret = -ENOMEM;
3716 		goto failed_mount;
3717 	}
3718 
3719 	if (ext4_proc_root)
3720 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3721 
3722 	if (sbi->s_proc)
3723 		proc_create_data("options", S_IRUGO, sbi->s_proc,
3724 				 &ext4_seq_options_fops, sb);
3725 
3726 	bgl_lock_init(sbi->s_blockgroup_lock);
3727 
3728 	for (i = 0; i < db_count; i++) {
3729 		block = descriptor_loc(sb, logical_sb_block, i);
3730 		sbi->s_group_desc[i] = sb_bread(sb, block);
3731 		if (!sbi->s_group_desc[i]) {
3732 			ext4_msg(sb, KERN_ERR,
3733 			       "can't read group descriptor %d", i);
3734 			db_count = i;
3735 			goto failed_mount2;
3736 		}
3737 	}
3738 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3739 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3740 		goto failed_mount2;
3741 	}
3742 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3743 		if (!ext4_fill_flex_info(sb)) {
3744 			ext4_msg(sb, KERN_ERR,
3745 			       "unable to initialize "
3746 			       "flex_bg meta info!");
3747 			goto failed_mount2;
3748 		}
3749 
3750 	sbi->s_gdb_count = db_count;
3751 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3752 	spin_lock_init(&sbi->s_next_gen_lock);
3753 
3754 	init_timer(&sbi->s_err_report);
3755 	sbi->s_err_report.function = print_daily_error_info;
3756 	sbi->s_err_report.data = (unsigned long) sb;
3757 
3758 	err = percpu_counter_init(&sbi->s_freeclusters_counter,
3759 			ext4_count_free_clusters(sb));
3760 	if (!err) {
3761 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3762 				ext4_count_free_inodes(sb));
3763 	}
3764 	if (!err) {
3765 		err = percpu_counter_init(&sbi->s_dirs_counter,
3766 				ext4_count_dirs(sb));
3767 	}
3768 	if (!err) {
3769 		err = percpu_counter_init(&sbi->s_dirtyclusters_counter, 0);
3770 	}
3771 	if (err) {
3772 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3773 		ret = err;
3774 		goto failed_mount3;
3775 	}
3776 
3777 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3778 	sbi->s_max_writeback_mb_bump = 128;
3779 	sbi->s_extent_max_zeroout_kb = 32;
3780 
3781 	/*
3782 	 * set up enough so that it can read an inode
3783 	 */
3784 	if (!test_opt(sb, NOLOAD) &&
3785 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3786 		sb->s_op = &ext4_sops;
3787 	else
3788 		sb->s_op = &ext4_nojournal_sops;
3789 	sb->s_export_op = &ext4_export_ops;
3790 	sb->s_xattr = ext4_xattr_handlers;
3791 #ifdef CONFIG_QUOTA
3792 	sb->s_qcop = &ext4_qctl_operations;
3793 	sb->dq_op = &ext4_quota_operations;
3794 
3795 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA)) {
3796 		/* Use qctl operations for hidden quota files. */
3797 		sb->s_qcop = &ext4_qctl_sysfile_operations;
3798 	}
3799 #endif
3800 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
3801 
3802 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3803 	mutex_init(&sbi->s_orphan_lock);
3804 	sbi->s_resize_flags = 0;
3805 
3806 	sb->s_root = NULL;
3807 
3808 	needs_recovery = (es->s_last_orphan != 0 ||
3809 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3810 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3811 
3812 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_MMP) &&
3813 	    !(sb->s_flags & MS_RDONLY))
3814 		if (ext4_multi_mount_protect(sb, le64_to_cpu(es->s_mmp_block)))
3815 			goto failed_mount3;
3816 
3817 	/*
3818 	 * The first inode we look at is the journal inode.  Don't try
3819 	 * root first: it may be modified in the journal!
3820 	 */
3821 	if (!test_opt(sb, NOLOAD) &&
3822 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3823 		if (ext4_load_journal(sb, es, journal_devnum))
3824 			goto failed_mount3;
3825 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3826 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3827 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3828 		       "suppressed and not mounted read-only");
3829 		goto failed_mount_wq;
3830 	} else {
3831 		clear_opt(sb, DATA_FLAGS);
3832 		sbi->s_journal = NULL;
3833 		needs_recovery = 0;
3834 		goto no_journal;
3835 	}
3836 
3837 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT) &&
3838 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3839 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3840 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3841 		goto failed_mount_wq;
3842 	}
3843 
3844 	if (!set_journal_csum_feature_set(sb)) {
3845 		ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
3846 			 "feature set");
3847 		goto failed_mount_wq;
3848 	}
3849 
3850 	/* We have now updated the journal if required, so we can
3851 	 * validate the data journaling mode. */
3852 	switch (test_opt(sb, DATA_FLAGS)) {
3853 	case 0:
3854 		/* No mode set, assume a default based on the journal
3855 		 * capabilities: ORDERED_DATA if the journal can
3856 		 * cope, else JOURNAL_DATA
3857 		 */
3858 		if (jbd2_journal_check_available_features
3859 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3860 			set_opt(sb, ORDERED_DATA);
3861 		else
3862 			set_opt(sb, JOURNAL_DATA);
3863 		break;
3864 
3865 	case EXT4_MOUNT_ORDERED_DATA:
3866 	case EXT4_MOUNT_WRITEBACK_DATA:
3867 		if (!jbd2_journal_check_available_features
3868 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3869 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3870 			       "requested data journaling mode");
3871 			goto failed_mount_wq;
3872 		}
3873 	default:
3874 		break;
3875 	}
3876 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3877 
3878 	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
3879 
3880 	/*
3881 	 * The journal may have updated the bg summary counts, so we
3882 	 * need to update the global counters.
3883 	 */
3884 	percpu_counter_set(&sbi->s_freeclusters_counter,
3885 			   ext4_count_free_clusters(sb));
3886 	percpu_counter_set(&sbi->s_freeinodes_counter,
3887 			   ext4_count_free_inodes(sb));
3888 	percpu_counter_set(&sbi->s_dirs_counter,
3889 			   ext4_count_dirs(sb));
3890 	percpu_counter_set(&sbi->s_dirtyclusters_counter, 0);
3891 
3892 no_journal:
3893 	/*
3894 	 * Get the # of file system overhead blocks from the
3895 	 * superblock if present.
3896 	 */
3897 	if (es->s_overhead_clusters)
3898 		sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters);
3899 	else {
3900 		ret = ext4_calculate_overhead(sb);
3901 		if (ret)
3902 			goto failed_mount_wq;
3903 	}
3904 
3905 	/*
3906 	 * The maximum number of concurrent works can be high and
3907 	 * concurrency isn't really necessary.  Limit it to 1.
3908 	 */
3909 	EXT4_SB(sb)->dio_unwritten_wq =
3910 		alloc_workqueue("ext4-dio-unwritten", WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
3911 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3912 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3913 		goto failed_mount_wq;
3914 	}
3915 
3916 	/*
3917 	 * The jbd2_journal_load will have done any necessary log recovery,
3918 	 * so we can safely mount the rest of the filesystem now.
3919 	 */
3920 
3921 	root = ext4_iget(sb, EXT4_ROOT_INO);
3922 	if (IS_ERR(root)) {
3923 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3924 		ret = PTR_ERR(root);
3925 		root = NULL;
3926 		goto failed_mount4;
3927 	}
3928 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3929 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3930 		iput(root);
3931 		goto failed_mount4;
3932 	}
3933 	sb->s_root = d_make_root(root);
3934 	if (!sb->s_root) {
3935 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3936 		ret = -ENOMEM;
3937 		goto failed_mount4;
3938 	}
3939 
3940 	if (ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY))
3941 		sb->s_flags |= MS_RDONLY;
3942 
3943 	/* determine the minimum size of new large inodes, if present */
3944 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3945 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3946 						     EXT4_GOOD_OLD_INODE_SIZE;
3947 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3948 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3949 			if (sbi->s_want_extra_isize <
3950 			    le16_to_cpu(es->s_want_extra_isize))
3951 				sbi->s_want_extra_isize =
3952 					le16_to_cpu(es->s_want_extra_isize);
3953 			if (sbi->s_want_extra_isize <
3954 			    le16_to_cpu(es->s_min_extra_isize))
3955 				sbi->s_want_extra_isize =
3956 					le16_to_cpu(es->s_min_extra_isize);
3957 		}
3958 	}
3959 	/* Check if enough inode space is available */
3960 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3961 							sbi->s_inode_size) {
3962 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3963 						       EXT4_GOOD_OLD_INODE_SIZE;
3964 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3965 			 "available");
3966 	}
3967 
3968 	err = ext4_setup_system_zone(sb);
3969 	if (err) {
3970 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3971 			 "zone (%d)", err);
3972 		goto failed_mount4a;
3973 	}
3974 
3975 	ext4_ext_init(sb);
3976 	err = ext4_mb_init(sb);
3977 	if (err) {
3978 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3979 			 err);
3980 		goto failed_mount5;
3981 	}
3982 
3983 	err = ext4_register_li_request(sb, first_not_zeroed);
3984 	if (err)
3985 		goto failed_mount6;
3986 
3987 	sbi->s_kobj.kset = ext4_kset;
3988 	init_completion(&sbi->s_kobj_unregister);
3989 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3990 				   "%s", sb->s_id);
3991 	if (err)
3992 		goto failed_mount7;
3993 
3994 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3995 	ext4_orphan_cleanup(sb, es);
3996 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3997 	if (needs_recovery) {
3998 		ext4_msg(sb, KERN_INFO, "recovery complete");
3999 		ext4_mark_recovery_complete(sb, es);
4000 	}
4001 	if (EXT4_SB(sb)->s_journal) {
4002 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
4003 			descr = " journalled data mode";
4004 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
4005 			descr = " ordered data mode";
4006 		else
4007 			descr = " writeback data mode";
4008 	} else
4009 		descr = "out journal";
4010 
4011 #ifdef CONFIG_QUOTA
4012 	/* Enable quota usage during mount. */
4013 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA) &&
4014 	    !(sb->s_flags & MS_RDONLY)) {
4015 		ret = ext4_enable_quotas(sb);
4016 		if (ret)
4017 			goto failed_mount7;
4018 	}
4019 #endif  /* CONFIG_QUOTA */
4020 
4021 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
4022 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
4023 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
4024 
4025 	if (es->s_error_count)
4026 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
4027 
4028 	kfree(orig_data);
4029 	return 0;
4030 
4031 cantfind_ext4:
4032 	if (!silent)
4033 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
4034 	goto failed_mount;
4035 
4036 failed_mount7:
4037 	ext4_unregister_li_request(sb);
4038 failed_mount6:
4039 	ext4_mb_release(sb);
4040 failed_mount5:
4041 	ext4_ext_release(sb);
4042 	ext4_release_system_zone(sb);
4043 failed_mount4a:
4044 	dput(sb->s_root);
4045 	sb->s_root = NULL;
4046 failed_mount4:
4047 	ext4_msg(sb, KERN_ERR, "mount failed");
4048 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
4049 failed_mount_wq:
4050 	if (sbi->s_journal) {
4051 		jbd2_journal_destroy(sbi->s_journal);
4052 		sbi->s_journal = NULL;
4053 	}
4054 failed_mount3:
4055 	del_timer(&sbi->s_err_report);
4056 	if (sbi->s_flex_groups)
4057 		ext4_kvfree(sbi->s_flex_groups);
4058 	percpu_counter_destroy(&sbi->s_freeclusters_counter);
4059 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
4060 	percpu_counter_destroy(&sbi->s_dirs_counter);
4061 	percpu_counter_destroy(&sbi->s_dirtyclusters_counter);
4062 	if (sbi->s_mmp_tsk)
4063 		kthread_stop(sbi->s_mmp_tsk);
4064 failed_mount2:
4065 	for (i = 0; i < db_count; i++)
4066 		brelse(sbi->s_group_desc[i]);
4067 	ext4_kvfree(sbi->s_group_desc);
4068 failed_mount:
4069 	if (sbi->s_chksum_driver)
4070 		crypto_free_shash(sbi->s_chksum_driver);
4071 	if (sbi->s_proc) {
4072 		remove_proc_entry("options", sbi->s_proc);
4073 		remove_proc_entry(sb->s_id, ext4_proc_root);
4074 	}
4075 #ifdef CONFIG_QUOTA
4076 	for (i = 0; i < MAXQUOTAS; i++)
4077 		kfree(sbi->s_qf_names[i]);
4078 #endif
4079 	ext4_blkdev_remove(sbi);
4080 	brelse(bh);
4081 out_fail:
4082 	sb->s_fs_info = NULL;
4083 	kfree(sbi->s_blockgroup_lock);
4084 	kfree(sbi);
4085 out_free_orig:
4086 	kfree(orig_data);
4087 	return ret;
4088 }
4089 
4090 /*
4091  * Setup any per-fs journal parameters now.  We'll do this both on
4092  * initial mount, once the journal has been initialised but before we've
4093  * done any recovery; and again on any subsequent remount.
4094  */
4095 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
4096 {
4097 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4098 
4099 	journal->j_commit_interval = sbi->s_commit_interval;
4100 	journal->j_min_batch_time = sbi->s_min_batch_time;
4101 	journal->j_max_batch_time = sbi->s_max_batch_time;
4102 
4103 	write_lock(&journal->j_state_lock);
4104 	if (test_opt(sb, BARRIER))
4105 		journal->j_flags |= JBD2_BARRIER;
4106 	else
4107 		journal->j_flags &= ~JBD2_BARRIER;
4108 	if (test_opt(sb, DATA_ERR_ABORT))
4109 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
4110 	else
4111 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
4112 	write_unlock(&journal->j_state_lock);
4113 }
4114 
4115 static journal_t *ext4_get_journal(struct super_block *sb,
4116 				   unsigned int journal_inum)
4117 {
4118 	struct inode *journal_inode;
4119 	journal_t *journal;
4120 
4121 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4122 
4123 	/* First, test for the existence of a valid inode on disk.  Bad
4124 	 * things happen if we iget() an unused inode, as the subsequent
4125 	 * iput() will try to delete it. */
4126 
4127 	journal_inode = ext4_iget(sb, journal_inum);
4128 	if (IS_ERR(journal_inode)) {
4129 		ext4_msg(sb, KERN_ERR, "no journal found");
4130 		return NULL;
4131 	}
4132 	if (!journal_inode->i_nlink) {
4133 		make_bad_inode(journal_inode);
4134 		iput(journal_inode);
4135 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
4136 		return NULL;
4137 	}
4138 
4139 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
4140 		  journal_inode, journal_inode->i_size);
4141 	if (!S_ISREG(journal_inode->i_mode)) {
4142 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
4143 		iput(journal_inode);
4144 		return NULL;
4145 	}
4146 
4147 	journal = jbd2_journal_init_inode(journal_inode);
4148 	if (!journal) {
4149 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
4150 		iput(journal_inode);
4151 		return NULL;
4152 	}
4153 	journal->j_private = sb;
4154 	ext4_init_journal_params(sb, journal);
4155 	return journal;
4156 }
4157 
4158 static journal_t *ext4_get_dev_journal(struct super_block *sb,
4159 				       dev_t j_dev)
4160 {
4161 	struct buffer_head *bh;
4162 	journal_t *journal;
4163 	ext4_fsblk_t start;
4164 	ext4_fsblk_t len;
4165 	int hblock, blocksize;
4166 	ext4_fsblk_t sb_block;
4167 	unsigned long offset;
4168 	struct ext4_super_block *es;
4169 	struct block_device *bdev;
4170 
4171 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4172 
4173 	bdev = ext4_blkdev_get(j_dev, sb);
4174 	if (bdev == NULL)
4175 		return NULL;
4176 
4177 	blocksize = sb->s_blocksize;
4178 	hblock = bdev_logical_block_size(bdev);
4179 	if (blocksize < hblock) {
4180 		ext4_msg(sb, KERN_ERR,
4181 			"blocksize too small for journal device");
4182 		goto out_bdev;
4183 	}
4184 
4185 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
4186 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
4187 	set_blocksize(bdev, blocksize);
4188 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
4189 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
4190 		       "external journal");
4191 		goto out_bdev;
4192 	}
4193 
4194 	es = (struct ext4_super_block *) (bh->b_data + offset);
4195 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
4196 	    !(le32_to_cpu(es->s_feature_incompat) &
4197 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
4198 		ext4_msg(sb, KERN_ERR, "external journal has "
4199 					"bad superblock");
4200 		brelse(bh);
4201 		goto out_bdev;
4202 	}
4203 
4204 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
4205 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
4206 		brelse(bh);
4207 		goto out_bdev;
4208 	}
4209 
4210 	len = ext4_blocks_count(es);
4211 	start = sb_block + 1;
4212 	brelse(bh);	/* we're done with the superblock */
4213 
4214 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
4215 					start, len, blocksize);
4216 	if (!journal) {
4217 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
4218 		goto out_bdev;
4219 	}
4220 	journal->j_private = sb;
4221 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
4222 	wait_on_buffer(journal->j_sb_buffer);
4223 	if (!buffer_uptodate(journal->j_sb_buffer)) {
4224 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
4225 		goto out_journal;
4226 	}
4227 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
4228 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
4229 					"user (unsupported) - %d",
4230 			be32_to_cpu(journal->j_superblock->s_nr_users));
4231 		goto out_journal;
4232 	}
4233 	EXT4_SB(sb)->journal_bdev = bdev;
4234 	ext4_init_journal_params(sb, journal);
4235 	return journal;
4236 
4237 out_journal:
4238 	jbd2_journal_destroy(journal);
4239 out_bdev:
4240 	ext4_blkdev_put(bdev);
4241 	return NULL;
4242 }
4243 
4244 static int ext4_load_journal(struct super_block *sb,
4245 			     struct ext4_super_block *es,
4246 			     unsigned long journal_devnum)
4247 {
4248 	journal_t *journal;
4249 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
4250 	dev_t journal_dev;
4251 	int err = 0;
4252 	int really_read_only;
4253 
4254 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4255 
4256 	if (journal_devnum &&
4257 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4258 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
4259 			"numbers have changed");
4260 		journal_dev = new_decode_dev(journal_devnum);
4261 	} else
4262 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
4263 
4264 	really_read_only = bdev_read_only(sb->s_bdev);
4265 
4266 	/*
4267 	 * Are we loading a blank journal or performing recovery after a
4268 	 * crash?  For recovery, we need to check in advance whether we
4269 	 * can get read-write access to the device.
4270 	 */
4271 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
4272 		if (sb->s_flags & MS_RDONLY) {
4273 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
4274 					"required on readonly filesystem");
4275 			if (really_read_only) {
4276 				ext4_msg(sb, KERN_ERR, "write access "
4277 					"unavailable, cannot proceed");
4278 				return -EROFS;
4279 			}
4280 			ext4_msg(sb, KERN_INFO, "write access will "
4281 			       "be enabled during recovery");
4282 		}
4283 	}
4284 
4285 	if (journal_inum && journal_dev) {
4286 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
4287 		       "and inode journals!");
4288 		return -EINVAL;
4289 	}
4290 
4291 	if (journal_inum) {
4292 		if (!(journal = ext4_get_journal(sb, journal_inum)))
4293 			return -EINVAL;
4294 	} else {
4295 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
4296 			return -EINVAL;
4297 	}
4298 
4299 	if (!(journal->j_flags & JBD2_BARRIER))
4300 		ext4_msg(sb, KERN_INFO, "barriers disabled");
4301 
4302 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
4303 		err = jbd2_journal_wipe(journal, !really_read_only);
4304 	if (!err) {
4305 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
4306 		if (save)
4307 			memcpy(save, ((char *) es) +
4308 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
4309 		err = jbd2_journal_load(journal);
4310 		if (save)
4311 			memcpy(((char *) es) + EXT4_S_ERR_START,
4312 			       save, EXT4_S_ERR_LEN);
4313 		kfree(save);
4314 	}
4315 
4316 	if (err) {
4317 		ext4_msg(sb, KERN_ERR, "error loading journal");
4318 		jbd2_journal_destroy(journal);
4319 		return err;
4320 	}
4321 
4322 	EXT4_SB(sb)->s_journal = journal;
4323 	ext4_clear_journal_err(sb, es);
4324 
4325 	if (!really_read_only && journal_devnum &&
4326 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
4327 		es->s_journal_dev = cpu_to_le32(journal_devnum);
4328 
4329 		/* Make sure we flush the recovery flag to disk. */
4330 		ext4_commit_super(sb, 1);
4331 	}
4332 
4333 	return 0;
4334 }
4335 
4336 static int ext4_commit_super(struct super_block *sb, int sync)
4337 {
4338 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
4339 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
4340 	int error = 0;
4341 
4342 	if (!sbh || block_device_ejected(sb))
4343 		return error;
4344 	if (buffer_write_io_error(sbh)) {
4345 		/*
4346 		 * Oh, dear.  A previous attempt to write the
4347 		 * superblock failed.  This could happen because the
4348 		 * USB device was yanked out.  Or it could happen to
4349 		 * be a transient write error and maybe the block will
4350 		 * be remapped.  Nothing we can do but to retry the
4351 		 * write and hope for the best.
4352 		 */
4353 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
4354 		       "superblock detected");
4355 		clear_buffer_write_io_error(sbh);
4356 		set_buffer_uptodate(sbh);
4357 	}
4358 	/*
4359 	 * If the file system is mounted read-only, don't update the
4360 	 * superblock write time.  This avoids updating the superblock
4361 	 * write time when we are mounting the root file system
4362 	 * read/only but we need to replay the journal; at that point,
4363 	 * for people who are east of GMT and who make their clock
4364 	 * tick in localtime for Windows bug-for-bug compatibility,
4365 	 * the clock is set in the future, and this will cause e2fsck
4366 	 * to complain and force a full file system check.
4367 	 */
4368 	if (!(sb->s_flags & MS_RDONLY))
4369 		es->s_wtime = cpu_to_le32(get_seconds());
4370 	if (sb->s_bdev->bd_part)
4371 		es->s_kbytes_written =
4372 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
4373 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
4374 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
4375 	else
4376 		es->s_kbytes_written =
4377 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
4378 	ext4_free_blocks_count_set(es,
4379 			EXT4_C2B(EXT4_SB(sb), percpu_counter_sum_positive(
4380 				&EXT4_SB(sb)->s_freeclusters_counter)));
4381 	es->s_free_inodes_count =
4382 		cpu_to_le32(percpu_counter_sum_positive(
4383 				&EXT4_SB(sb)->s_freeinodes_counter));
4384 	BUFFER_TRACE(sbh, "marking dirty");
4385 	ext4_superblock_csum_set(sb);
4386 	mark_buffer_dirty(sbh);
4387 	if (sync) {
4388 		error = sync_dirty_buffer(sbh);
4389 		if (error)
4390 			return error;
4391 
4392 		error = buffer_write_io_error(sbh);
4393 		if (error) {
4394 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4395 			       "superblock");
4396 			clear_buffer_write_io_error(sbh);
4397 			set_buffer_uptodate(sbh);
4398 		}
4399 	}
4400 	return error;
4401 }
4402 
4403 /*
4404  * Have we just finished recovery?  If so, and if we are mounting (or
4405  * remounting) the filesystem readonly, then we will end up with a
4406  * consistent fs on disk.  Record that fact.
4407  */
4408 static void ext4_mark_recovery_complete(struct super_block *sb,
4409 					struct ext4_super_block *es)
4410 {
4411 	journal_t *journal = EXT4_SB(sb)->s_journal;
4412 
4413 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4414 		BUG_ON(journal != NULL);
4415 		return;
4416 	}
4417 	jbd2_journal_lock_updates(journal);
4418 	if (jbd2_journal_flush(journal) < 0)
4419 		goto out;
4420 
4421 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4422 	    sb->s_flags & MS_RDONLY) {
4423 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4424 		ext4_commit_super(sb, 1);
4425 	}
4426 
4427 out:
4428 	jbd2_journal_unlock_updates(journal);
4429 }
4430 
4431 /*
4432  * If we are mounting (or read-write remounting) a filesystem whose journal
4433  * has recorded an error from a previous lifetime, move that error to the
4434  * main filesystem now.
4435  */
4436 static void ext4_clear_journal_err(struct super_block *sb,
4437 				   struct ext4_super_block *es)
4438 {
4439 	journal_t *journal;
4440 	int j_errno;
4441 	const char *errstr;
4442 
4443 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4444 
4445 	journal = EXT4_SB(sb)->s_journal;
4446 
4447 	/*
4448 	 * Now check for any error status which may have been recorded in the
4449 	 * journal by a prior ext4_error() or ext4_abort()
4450 	 */
4451 
4452 	j_errno = jbd2_journal_errno(journal);
4453 	if (j_errno) {
4454 		char nbuf[16];
4455 
4456 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4457 		ext4_warning(sb, "Filesystem error recorded "
4458 			     "from previous mount: %s", errstr);
4459 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4460 
4461 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4462 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4463 		ext4_commit_super(sb, 1);
4464 
4465 		jbd2_journal_clear_err(journal);
4466 		jbd2_journal_update_sb_errno(journal);
4467 	}
4468 }
4469 
4470 /*
4471  * Force the running and committing transactions to commit,
4472  * and wait on the commit.
4473  */
4474 int ext4_force_commit(struct super_block *sb)
4475 {
4476 	journal_t *journal;
4477 	int ret = 0;
4478 
4479 	if (sb->s_flags & MS_RDONLY)
4480 		return 0;
4481 
4482 	journal = EXT4_SB(sb)->s_journal;
4483 	if (journal)
4484 		ret = ext4_journal_force_commit(journal);
4485 
4486 	return ret;
4487 }
4488 
4489 static int ext4_sync_fs(struct super_block *sb, int wait)
4490 {
4491 	int ret = 0;
4492 	tid_t target;
4493 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4494 
4495 	trace_ext4_sync_fs(sb, wait);
4496 	flush_workqueue(sbi->dio_unwritten_wq);
4497 	/*
4498 	 * Writeback quota in non-journalled quota case - journalled quota has
4499 	 * no dirty dquots
4500 	 */
4501 	dquot_writeback_dquots(sb, -1);
4502 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4503 		if (wait)
4504 			jbd2_log_wait_commit(sbi->s_journal, target);
4505 	}
4506 	return ret;
4507 }
4508 
4509 /*
4510  * LVM calls this function before a (read-only) snapshot is created.  This
4511  * gives us a chance to flush the journal completely and mark the fs clean.
4512  *
4513  * Note that only this function cannot bring a filesystem to be in a clean
4514  * state independently. It relies on upper layer to stop all data & metadata
4515  * modifications.
4516  */
4517 static int ext4_freeze(struct super_block *sb)
4518 {
4519 	int error = 0;
4520 	journal_t *journal;
4521 
4522 	if (sb->s_flags & MS_RDONLY)
4523 		return 0;
4524 
4525 	journal = EXT4_SB(sb)->s_journal;
4526 
4527 	/* Now we set up the journal barrier. */
4528 	jbd2_journal_lock_updates(journal);
4529 
4530 	/*
4531 	 * Don't clear the needs_recovery flag if we failed to flush
4532 	 * the journal.
4533 	 */
4534 	error = jbd2_journal_flush(journal);
4535 	if (error < 0)
4536 		goto out;
4537 
4538 	/* Journal blocked and flushed, clear needs_recovery flag. */
4539 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4540 	error = ext4_commit_super(sb, 1);
4541 out:
4542 	/* we rely on upper layer to stop further updates */
4543 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4544 	return error;
4545 }
4546 
4547 /*
4548  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4549  * flag here, even though the filesystem is not technically dirty yet.
4550  */
4551 static int ext4_unfreeze(struct super_block *sb)
4552 {
4553 	if (sb->s_flags & MS_RDONLY)
4554 		return 0;
4555 
4556 	/* Reset the needs_recovery flag before the fs is unlocked. */
4557 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4558 	ext4_commit_super(sb, 1);
4559 	return 0;
4560 }
4561 
4562 /*
4563  * Structure to save mount options for ext4_remount's benefit
4564  */
4565 struct ext4_mount_options {
4566 	unsigned long s_mount_opt;
4567 	unsigned long s_mount_opt2;
4568 	kuid_t s_resuid;
4569 	kgid_t s_resgid;
4570 	unsigned long s_commit_interval;
4571 	u32 s_min_batch_time, s_max_batch_time;
4572 #ifdef CONFIG_QUOTA
4573 	int s_jquota_fmt;
4574 	char *s_qf_names[MAXQUOTAS];
4575 #endif
4576 };
4577 
4578 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4579 {
4580 	struct ext4_super_block *es;
4581 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4582 	unsigned long old_sb_flags;
4583 	struct ext4_mount_options old_opts;
4584 	int enable_quota = 0;
4585 	ext4_group_t g;
4586 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4587 	int err = 0;
4588 #ifdef CONFIG_QUOTA
4589 	int i;
4590 #endif
4591 	char *orig_data = kstrdup(data, GFP_KERNEL);
4592 
4593 	/* Store the original options */
4594 	old_sb_flags = sb->s_flags;
4595 	old_opts.s_mount_opt = sbi->s_mount_opt;
4596 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4597 	old_opts.s_resuid = sbi->s_resuid;
4598 	old_opts.s_resgid = sbi->s_resgid;
4599 	old_opts.s_commit_interval = sbi->s_commit_interval;
4600 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4601 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4602 #ifdef CONFIG_QUOTA
4603 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4604 	for (i = 0; i < MAXQUOTAS; i++)
4605 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4606 #endif
4607 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4608 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4609 
4610 	/*
4611 	 * Allow the "check" option to be passed as a remount option.
4612 	 */
4613 	if (!parse_options(data, sb, NULL, &journal_ioprio, 1)) {
4614 		err = -EINVAL;
4615 		goto restore_opts;
4616 	}
4617 
4618 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4619 		ext4_abort(sb, "Abort forced by user");
4620 
4621 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4622 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4623 
4624 	es = sbi->s_es;
4625 
4626 	if (sbi->s_journal) {
4627 		ext4_init_journal_params(sb, sbi->s_journal);
4628 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4629 	}
4630 
4631 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
4632 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4633 			err = -EROFS;
4634 			goto restore_opts;
4635 		}
4636 
4637 		if (*flags & MS_RDONLY) {
4638 			err = dquot_suspend(sb, -1);
4639 			if (err < 0)
4640 				goto restore_opts;
4641 
4642 			/*
4643 			 * First of all, the unconditional stuff we have to do
4644 			 * to disable replay of the journal when we next remount
4645 			 */
4646 			sb->s_flags |= MS_RDONLY;
4647 
4648 			/*
4649 			 * OK, test if we are remounting a valid rw partition
4650 			 * readonly, and if so set the rdonly flag and then
4651 			 * mark the partition as valid again.
4652 			 */
4653 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4654 			    (sbi->s_mount_state & EXT4_VALID_FS))
4655 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4656 
4657 			if (sbi->s_journal)
4658 				ext4_mark_recovery_complete(sb, es);
4659 		} else {
4660 			/* Make sure we can mount this feature set readwrite */
4661 			if (!ext4_feature_set_ok(sb, 0)) {
4662 				err = -EROFS;
4663 				goto restore_opts;
4664 			}
4665 			/*
4666 			 * Make sure the group descriptor checksums
4667 			 * are sane.  If they aren't, refuse to remount r/w.
4668 			 */
4669 			for (g = 0; g < sbi->s_groups_count; g++) {
4670 				struct ext4_group_desc *gdp =
4671 					ext4_get_group_desc(sb, g, NULL);
4672 
4673 				if (!ext4_group_desc_csum_verify(sb, g, gdp)) {
4674 					ext4_msg(sb, KERN_ERR,
4675 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4676 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4677 					       le16_to_cpu(gdp->bg_checksum));
4678 					err = -EINVAL;
4679 					goto restore_opts;
4680 				}
4681 			}
4682 
4683 			/*
4684 			 * If we have an unprocessed orphan list hanging
4685 			 * around from a previously readonly bdev mount,
4686 			 * require a full umount/remount for now.
4687 			 */
4688 			if (es->s_last_orphan) {
4689 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4690 				       "remount RDWR because of unprocessed "
4691 				       "orphan inode list.  Please "
4692 				       "umount/remount instead");
4693 				err = -EINVAL;
4694 				goto restore_opts;
4695 			}
4696 
4697 			/*
4698 			 * Mounting a RDONLY partition read-write, so reread
4699 			 * and store the current valid flag.  (It may have
4700 			 * been changed by e2fsck since we originally mounted
4701 			 * the partition.)
4702 			 */
4703 			if (sbi->s_journal)
4704 				ext4_clear_journal_err(sb, es);
4705 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4706 			if (!ext4_setup_super(sb, es, 0))
4707 				sb->s_flags &= ~MS_RDONLY;
4708 			if (EXT4_HAS_INCOMPAT_FEATURE(sb,
4709 						     EXT4_FEATURE_INCOMPAT_MMP))
4710 				if (ext4_multi_mount_protect(sb,
4711 						le64_to_cpu(es->s_mmp_block))) {
4712 					err = -EROFS;
4713 					goto restore_opts;
4714 				}
4715 			enable_quota = 1;
4716 		}
4717 	}
4718 
4719 	/*
4720 	 * Reinitialize lazy itable initialization thread based on
4721 	 * current settings
4722 	 */
4723 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4724 		ext4_unregister_li_request(sb);
4725 	else {
4726 		ext4_group_t first_not_zeroed;
4727 		first_not_zeroed = ext4_has_uninit_itable(sb);
4728 		ext4_register_li_request(sb, first_not_zeroed);
4729 	}
4730 
4731 	ext4_setup_system_zone(sb);
4732 	if (sbi->s_journal == NULL)
4733 		ext4_commit_super(sb, 1);
4734 
4735 #ifdef CONFIG_QUOTA
4736 	/* Release old quota file names */
4737 	for (i = 0; i < MAXQUOTAS; i++)
4738 		if (old_opts.s_qf_names[i] &&
4739 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4740 			kfree(old_opts.s_qf_names[i]);
4741 	if (enable_quota) {
4742 		if (sb_any_quota_suspended(sb))
4743 			dquot_resume(sb, -1);
4744 		else if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4745 					EXT4_FEATURE_RO_COMPAT_QUOTA)) {
4746 			err = ext4_enable_quotas(sb);
4747 			if (err)
4748 				goto restore_opts;
4749 		}
4750 	}
4751 #endif
4752 
4753 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4754 	kfree(orig_data);
4755 	return 0;
4756 
4757 restore_opts:
4758 	sb->s_flags = old_sb_flags;
4759 	sbi->s_mount_opt = old_opts.s_mount_opt;
4760 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4761 	sbi->s_resuid = old_opts.s_resuid;
4762 	sbi->s_resgid = old_opts.s_resgid;
4763 	sbi->s_commit_interval = old_opts.s_commit_interval;
4764 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4765 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4766 #ifdef CONFIG_QUOTA
4767 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4768 	for (i = 0; i < MAXQUOTAS; i++) {
4769 		if (sbi->s_qf_names[i] &&
4770 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4771 			kfree(sbi->s_qf_names[i]);
4772 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4773 	}
4774 #endif
4775 	kfree(orig_data);
4776 	return err;
4777 }
4778 
4779 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4780 {
4781 	struct super_block *sb = dentry->d_sb;
4782 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4783 	struct ext4_super_block *es = sbi->s_es;
4784 	ext4_fsblk_t overhead = 0;
4785 	u64 fsid;
4786 	s64 bfree;
4787 
4788 	if (!test_opt(sb, MINIX_DF))
4789 		overhead = sbi->s_overhead;
4790 
4791 	buf->f_type = EXT4_SUPER_MAGIC;
4792 	buf->f_bsize = sb->s_blocksize;
4793 	buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead);
4794 	bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
4795 		percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
4796 	/* prevent underflow in case that few free space is available */
4797 	buf->f_bfree = EXT4_C2B(sbi, max_t(s64, bfree, 0));
4798 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4799 	if (buf->f_bfree < ext4_r_blocks_count(es))
4800 		buf->f_bavail = 0;
4801 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4802 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4803 	buf->f_namelen = EXT4_NAME_LEN;
4804 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4805 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4806 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4807 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4808 
4809 	return 0;
4810 }
4811 
4812 /* Helper function for writing quotas on sync - we need to start transaction
4813  * before quota file is locked for write. Otherwise the are possible deadlocks:
4814  * Process 1                         Process 2
4815  * ext4_create()                     quota_sync()
4816  *   jbd2_journal_start()                  write_dquot()
4817  *   dquot_initialize()                         down(dqio_mutex)
4818  *     down(dqio_mutex)                    jbd2_journal_start()
4819  *
4820  */
4821 
4822 #ifdef CONFIG_QUOTA
4823 
4824 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4825 {
4826 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_id.type];
4827 }
4828 
4829 static int ext4_write_dquot(struct dquot *dquot)
4830 {
4831 	int ret, err;
4832 	handle_t *handle;
4833 	struct inode *inode;
4834 
4835 	inode = dquot_to_inode(dquot);
4836 	handle = ext4_journal_start(inode,
4837 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4838 	if (IS_ERR(handle))
4839 		return PTR_ERR(handle);
4840 	ret = dquot_commit(dquot);
4841 	err = ext4_journal_stop(handle);
4842 	if (!ret)
4843 		ret = err;
4844 	return ret;
4845 }
4846 
4847 static int ext4_acquire_dquot(struct dquot *dquot)
4848 {
4849 	int ret, err;
4850 	handle_t *handle;
4851 
4852 	handle = ext4_journal_start(dquot_to_inode(dquot),
4853 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4854 	if (IS_ERR(handle))
4855 		return PTR_ERR(handle);
4856 	ret = dquot_acquire(dquot);
4857 	err = ext4_journal_stop(handle);
4858 	if (!ret)
4859 		ret = err;
4860 	return ret;
4861 }
4862 
4863 static int ext4_release_dquot(struct dquot *dquot)
4864 {
4865 	int ret, err;
4866 	handle_t *handle;
4867 
4868 	handle = ext4_journal_start(dquot_to_inode(dquot),
4869 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4870 	if (IS_ERR(handle)) {
4871 		/* Release dquot anyway to avoid endless cycle in dqput() */
4872 		dquot_release(dquot);
4873 		return PTR_ERR(handle);
4874 	}
4875 	ret = dquot_release(dquot);
4876 	err = ext4_journal_stop(handle);
4877 	if (!ret)
4878 		ret = err;
4879 	return ret;
4880 }
4881 
4882 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4883 {
4884 	/* Are we journaling quotas? */
4885 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4886 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4887 		dquot_mark_dquot_dirty(dquot);
4888 		return ext4_write_dquot(dquot);
4889 	} else {
4890 		return dquot_mark_dquot_dirty(dquot);
4891 	}
4892 }
4893 
4894 static int ext4_write_info(struct super_block *sb, int type)
4895 {
4896 	int ret, err;
4897 	handle_t *handle;
4898 
4899 	/* Data block + inode block */
4900 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
4901 	if (IS_ERR(handle))
4902 		return PTR_ERR(handle);
4903 	ret = dquot_commit_info(sb, type);
4904 	err = ext4_journal_stop(handle);
4905 	if (!ret)
4906 		ret = err;
4907 	return ret;
4908 }
4909 
4910 /*
4911  * Turn on quotas during mount time - we need to find
4912  * the quota file and such...
4913  */
4914 static int ext4_quota_on_mount(struct super_block *sb, int type)
4915 {
4916 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4917 					EXT4_SB(sb)->s_jquota_fmt, type);
4918 }
4919 
4920 /*
4921  * Standard function to be called on quota_on
4922  */
4923 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4924 			 struct path *path)
4925 {
4926 	int err;
4927 
4928 	if (!test_opt(sb, QUOTA))
4929 		return -EINVAL;
4930 
4931 	/* Quotafile not on the same filesystem? */
4932 	if (path->dentry->d_sb != sb)
4933 		return -EXDEV;
4934 	/* Journaling quota? */
4935 	if (EXT4_SB(sb)->s_qf_names[type]) {
4936 		/* Quotafile not in fs root? */
4937 		if (path->dentry->d_parent != sb->s_root)
4938 			ext4_msg(sb, KERN_WARNING,
4939 				"Quota file not on filesystem root. "
4940 				"Journaled quota will not work");
4941 	}
4942 
4943 	/*
4944 	 * When we journal data on quota file, we have to flush journal to see
4945 	 * all updates to the file when we bypass pagecache...
4946 	 */
4947 	if (EXT4_SB(sb)->s_journal &&
4948 	    ext4_should_journal_data(path->dentry->d_inode)) {
4949 		/*
4950 		 * We don't need to lock updates but journal_flush() could
4951 		 * otherwise be livelocked...
4952 		 */
4953 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4954 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4955 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4956 		if (err)
4957 			return err;
4958 	}
4959 
4960 	return dquot_quota_on(sb, type, format_id, path);
4961 }
4962 
4963 static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
4964 			     unsigned int flags)
4965 {
4966 	int err;
4967 	struct inode *qf_inode;
4968 	unsigned long qf_inums[MAXQUOTAS] = {
4969 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4970 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4971 	};
4972 
4973 	BUG_ON(!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA));
4974 
4975 	if (!qf_inums[type])
4976 		return -EPERM;
4977 
4978 	qf_inode = ext4_iget(sb, qf_inums[type]);
4979 	if (IS_ERR(qf_inode)) {
4980 		ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]);
4981 		return PTR_ERR(qf_inode);
4982 	}
4983 
4984 	err = dquot_enable(qf_inode, type, format_id, flags);
4985 	iput(qf_inode);
4986 
4987 	return err;
4988 }
4989 
4990 /* Enable usage tracking for all quota types. */
4991 static int ext4_enable_quotas(struct super_block *sb)
4992 {
4993 	int type, err = 0;
4994 	unsigned long qf_inums[MAXQUOTAS] = {
4995 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
4996 		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
4997 	};
4998 
4999 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;
5000 	for (type = 0; type < MAXQUOTAS; type++) {
5001 		if (qf_inums[type]) {
5002 			err = ext4_quota_enable(sb, type, QFMT_VFS_V1,
5003 						DQUOT_USAGE_ENABLED);
5004 			if (err) {
5005 				ext4_warning(sb,
5006 					"Failed to enable quota (type=%d) "
5007 					"tracking. Please run e2fsck to fix.",
5008 					type);
5009 				return err;
5010 			}
5011 		}
5012 	}
5013 	return 0;
5014 }
5015 
5016 /*
5017  * quota_on function that is used when QUOTA feature is set.
5018  */
5019 static int ext4_quota_on_sysfile(struct super_block *sb, int type,
5020 				 int format_id)
5021 {
5022 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5023 		return -EINVAL;
5024 
5025 	/*
5026 	 * USAGE was enabled at mount time. Only need to enable LIMITS now.
5027 	 */
5028 	return ext4_quota_enable(sb, type, format_id, DQUOT_LIMITS_ENABLED);
5029 }
5030 
5031 static int ext4_quota_off(struct super_block *sb, int type)
5032 {
5033 	struct inode *inode = sb_dqopt(sb)->files[type];
5034 	handle_t *handle;
5035 
5036 	/* Force all delayed allocation blocks to be allocated.
5037 	 * Caller already holds s_umount sem */
5038 	if (test_opt(sb, DELALLOC))
5039 		sync_filesystem(sb);
5040 
5041 	if (!inode)
5042 		goto out;
5043 
5044 	/* Update modification times of quota files when userspace can
5045 	 * start looking at them */
5046 	handle = ext4_journal_start(inode, 1);
5047 	if (IS_ERR(handle))
5048 		goto out;
5049 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
5050 	ext4_mark_inode_dirty(handle, inode);
5051 	ext4_journal_stop(handle);
5052 
5053 out:
5054 	return dquot_quota_off(sb, type);
5055 }
5056 
5057 /*
5058  * quota_off function that is used when QUOTA feature is set.
5059  */
5060 static int ext4_quota_off_sysfile(struct super_block *sb, int type)
5061 {
5062 	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_QUOTA))
5063 		return -EINVAL;
5064 
5065 	/* Disable only the limits. */
5066 	return dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);
5067 }
5068 
5069 /* Read data from quotafile - avoid pagecache and such because we cannot afford
5070  * acquiring the locks... As quota files are never truncated and quota code
5071  * itself serializes the operations (and no one else should touch the files)
5072  * we don't have to be afraid of races */
5073 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
5074 			       size_t len, loff_t off)
5075 {
5076 	struct inode *inode = sb_dqopt(sb)->files[type];
5077 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5078 	int err = 0;
5079 	int offset = off & (sb->s_blocksize - 1);
5080 	int tocopy;
5081 	size_t toread;
5082 	struct buffer_head *bh;
5083 	loff_t i_size = i_size_read(inode);
5084 
5085 	if (off > i_size)
5086 		return 0;
5087 	if (off+len > i_size)
5088 		len = i_size-off;
5089 	toread = len;
5090 	while (toread > 0) {
5091 		tocopy = sb->s_blocksize - offset < toread ?
5092 				sb->s_blocksize - offset : toread;
5093 		bh = ext4_bread(NULL, inode, blk, 0, &err);
5094 		if (err)
5095 			return err;
5096 		if (!bh)	/* A hole? */
5097 			memset(data, 0, tocopy);
5098 		else
5099 			memcpy(data, bh->b_data+offset, tocopy);
5100 		brelse(bh);
5101 		offset = 0;
5102 		toread -= tocopy;
5103 		data += tocopy;
5104 		blk++;
5105 	}
5106 	return len;
5107 }
5108 
5109 /* Write to quotafile (we know the transaction is already started and has
5110  * enough credits) */
5111 static ssize_t ext4_quota_write(struct super_block *sb, int type,
5112 				const char *data, size_t len, loff_t off)
5113 {
5114 	struct inode *inode = sb_dqopt(sb)->files[type];
5115 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
5116 	int err = 0;
5117 	int offset = off & (sb->s_blocksize - 1);
5118 	struct buffer_head *bh;
5119 	handle_t *handle = journal_current_handle();
5120 
5121 	if (EXT4_SB(sb)->s_journal && !handle) {
5122 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5123 			" cancelled because transaction is not started",
5124 			(unsigned long long)off, (unsigned long long)len);
5125 		return -EIO;
5126 	}
5127 	/*
5128 	 * Since we account only one data block in transaction credits,
5129 	 * then it is impossible to cross a block boundary.
5130 	 */
5131 	if (sb->s_blocksize - offset < len) {
5132 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
5133 			" cancelled because not block aligned",
5134 			(unsigned long long)off, (unsigned long long)len);
5135 		return -EIO;
5136 	}
5137 
5138 	bh = ext4_bread(handle, inode, blk, 1, &err);
5139 	if (!bh)
5140 		goto out;
5141 	err = ext4_journal_get_write_access(handle, bh);
5142 	if (err) {
5143 		brelse(bh);
5144 		goto out;
5145 	}
5146 	lock_buffer(bh);
5147 	memcpy(bh->b_data+offset, data, len);
5148 	flush_dcache_page(bh->b_page);
5149 	unlock_buffer(bh);
5150 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
5151 	brelse(bh);
5152 out:
5153 	if (err)
5154 		return err;
5155 	if (inode->i_size < off + len) {
5156 		i_size_write(inode, off + len);
5157 		EXT4_I(inode)->i_disksize = inode->i_size;
5158 		ext4_mark_inode_dirty(handle, inode);
5159 	}
5160 	return len;
5161 }
5162 
5163 #endif
5164 
5165 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
5166 		       const char *dev_name, void *data)
5167 {
5168 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
5169 }
5170 
5171 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5172 static inline void register_as_ext2(void)
5173 {
5174 	int err = register_filesystem(&ext2_fs_type);
5175 	if (err)
5176 		printk(KERN_WARNING
5177 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
5178 }
5179 
5180 static inline void unregister_as_ext2(void)
5181 {
5182 	unregister_filesystem(&ext2_fs_type);
5183 }
5184 
5185 static inline int ext2_feature_set_ok(struct super_block *sb)
5186 {
5187 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP))
5188 		return 0;
5189 	if (sb->s_flags & MS_RDONLY)
5190 		return 1;
5191 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))
5192 		return 0;
5193 	return 1;
5194 }
5195 MODULE_ALIAS("ext2");
5196 #else
5197 static inline void register_as_ext2(void) { }
5198 static inline void unregister_as_ext2(void) { }
5199 static inline int ext2_feature_set_ok(struct super_block *sb) { return 0; }
5200 #endif
5201 
5202 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
5203 static inline void register_as_ext3(void)
5204 {
5205 	int err = register_filesystem(&ext3_fs_type);
5206 	if (err)
5207 		printk(KERN_WARNING
5208 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
5209 }
5210 
5211 static inline void unregister_as_ext3(void)
5212 {
5213 	unregister_filesystem(&ext3_fs_type);
5214 }
5215 
5216 static inline int ext3_feature_set_ok(struct super_block *sb)
5217 {
5218 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT3_FEATURE_INCOMPAT_SUPP))
5219 		return 0;
5220 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
5221 		return 0;
5222 	if (sb->s_flags & MS_RDONLY)
5223 		return 1;
5224 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT3_FEATURE_RO_COMPAT_SUPP))
5225 		return 0;
5226 	return 1;
5227 }
5228 MODULE_ALIAS("ext3");
5229 #else
5230 static inline void register_as_ext3(void) { }
5231 static inline void unregister_as_ext3(void) { }
5232 static inline int ext3_feature_set_ok(struct super_block *sb) { return 0; }
5233 #endif
5234 
5235 static struct file_system_type ext4_fs_type = {
5236 	.owner		= THIS_MODULE,
5237 	.name		= "ext4",
5238 	.mount		= ext4_mount,
5239 	.kill_sb	= kill_block_super,
5240 	.fs_flags	= FS_REQUIRES_DEV,
5241 };
5242 
5243 static int __init ext4_init_feat_adverts(void)
5244 {
5245 	struct ext4_features *ef;
5246 	int ret = -ENOMEM;
5247 
5248 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
5249 	if (!ef)
5250 		goto out;
5251 
5252 	ef->f_kobj.kset = ext4_kset;
5253 	init_completion(&ef->f_kobj_unregister);
5254 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
5255 				   "features");
5256 	if (ret) {
5257 		kfree(ef);
5258 		goto out;
5259 	}
5260 
5261 	ext4_feat = ef;
5262 	ret = 0;
5263 out:
5264 	return ret;
5265 }
5266 
5267 static void ext4_exit_feat_adverts(void)
5268 {
5269 	kobject_put(&ext4_feat->f_kobj);
5270 	wait_for_completion(&ext4_feat->f_kobj_unregister);
5271 	kfree(ext4_feat);
5272 }
5273 
5274 /* Shared across all ext4 file systems */
5275 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
5276 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
5277 
5278 static int __init ext4_init_fs(void)
5279 {
5280 	int i, err;
5281 
5282 	ext4_li_info = NULL;
5283 	mutex_init(&ext4_li_mtx);
5284 
5285 	ext4_check_flag_values();
5286 
5287 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
5288 		mutex_init(&ext4__aio_mutex[i]);
5289 		init_waitqueue_head(&ext4__ioend_wq[i]);
5290 	}
5291 
5292 	err = ext4_init_pageio();
5293 	if (err)
5294 		return err;
5295 	err = ext4_init_system_zone();
5296 	if (err)
5297 		goto out6;
5298 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
5299 	if (!ext4_kset) {
5300 		err = -ENOMEM;
5301 		goto out5;
5302 	}
5303 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
5304 
5305 	err = ext4_init_feat_adverts();
5306 	if (err)
5307 		goto out4;
5308 
5309 	err = ext4_init_mballoc();
5310 	if (err)
5311 		goto out3;
5312 
5313 	err = ext4_init_xattr();
5314 	if (err)
5315 		goto out2;
5316 	err = init_inodecache();
5317 	if (err)
5318 		goto out1;
5319 	register_as_ext3();
5320 	register_as_ext2();
5321 	err = register_filesystem(&ext4_fs_type);
5322 	if (err)
5323 		goto out;
5324 
5325 	return 0;
5326 out:
5327 	unregister_as_ext2();
5328 	unregister_as_ext3();
5329 	destroy_inodecache();
5330 out1:
5331 	ext4_exit_xattr();
5332 out2:
5333 	ext4_exit_mballoc();
5334 out3:
5335 	ext4_exit_feat_adverts();
5336 out4:
5337 	if (ext4_proc_root)
5338 		remove_proc_entry("fs/ext4", NULL);
5339 	kset_unregister(ext4_kset);
5340 out5:
5341 	ext4_exit_system_zone();
5342 out6:
5343 	ext4_exit_pageio();
5344 	return err;
5345 }
5346 
5347 static void __exit ext4_exit_fs(void)
5348 {
5349 	ext4_destroy_lazyinit_thread();
5350 	unregister_as_ext2();
5351 	unregister_as_ext3();
5352 	unregister_filesystem(&ext4_fs_type);
5353 	destroy_inodecache();
5354 	ext4_exit_xattr();
5355 	ext4_exit_mballoc();
5356 	ext4_exit_feat_adverts();
5357 	remove_proc_entry("fs/ext4", NULL);
5358 	kset_unregister(ext4_kset);
5359 	ext4_exit_system_zone();
5360 	ext4_exit_pageio();
5361 }
5362 
5363 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
5364 MODULE_DESCRIPTION("Fourth Extended Filesystem");
5365 MODULE_LICENSE("GPL");
5366 module_init(ext4_init_fs)
5367 module_exit(ext4_exit_fs)
5368