xref: /openbmc/linux/fs/ext4/super.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 <asm/uaccess.h>
42 
43 #include <linux/kthread.h>
44 #include <linux/freezer.h>
45 
46 #include "ext4.h"
47 #include "ext4_jbd2.h"
48 #include "xattr.h"
49 #include "acl.h"
50 #include "mballoc.h"
51 
52 #define CREATE_TRACE_POINTS
53 #include <trace/events/ext4.h>
54 
55 static struct proc_dir_entry *ext4_proc_root;
56 static struct kset *ext4_kset;
57 struct ext4_lazy_init *ext4_li_info;
58 struct mutex ext4_li_mtx;
59 struct ext4_features *ext4_feat;
60 
61 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
62 			     unsigned long journal_devnum);
63 static int ext4_commit_super(struct super_block *sb, int sync);
64 static void ext4_mark_recovery_complete(struct super_block *sb,
65 					struct ext4_super_block *es);
66 static void ext4_clear_journal_err(struct super_block *sb,
67 				   struct ext4_super_block *es);
68 static int ext4_sync_fs(struct super_block *sb, int wait);
69 static const char *ext4_decode_error(struct super_block *sb, int errno,
70 				     char nbuf[16]);
71 static int ext4_remount(struct super_block *sb, int *flags, char *data);
72 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
73 static int ext4_unfreeze(struct super_block *sb);
74 static void ext4_write_super(struct super_block *sb);
75 static int ext4_freeze(struct super_block *sb);
76 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
77 		       const char *dev_name, void *data);
78 static void ext4_destroy_lazyinit_thread(void);
79 static void ext4_unregister_li_request(struct super_block *sb);
80 static void ext4_clear_request_list(void);
81 
82 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
83 static struct file_system_type ext3_fs_type = {
84 	.owner		= THIS_MODULE,
85 	.name		= "ext3",
86 	.mount		= ext4_mount,
87 	.kill_sb	= kill_block_super,
88 	.fs_flags	= FS_REQUIRES_DEV,
89 };
90 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
91 #else
92 #define IS_EXT3_SB(sb) (0)
93 #endif
94 
95 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
96 			       struct ext4_group_desc *bg)
97 {
98 	return le32_to_cpu(bg->bg_block_bitmap_lo) |
99 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
100 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
101 }
102 
103 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
104 			       struct ext4_group_desc *bg)
105 {
106 	return le32_to_cpu(bg->bg_inode_bitmap_lo) |
107 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
108 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
109 }
110 
111 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
112 			      struct ext4_group_desc *bg)
113 {
114 	return le32_to_cpu(bg->bg_inode_table_lo) |
115 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
116 		 (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
117 }
118 
119 __u32 ext4_free_blks_count(struct super_block *sb,
120 			      struct ext4_group_desc *bg)
121 {
122 	return le16_to_cpu(bg->bg_free_blocks_count_lo) |
123 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
124 		 (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
125 }
126 
127 __u32 ext4_free_inodes_count(struct super_block *sb,
128 			      struct ext4_group_desc *bg)
129 {
130 	return le16_to_cpu(bg->bg_free_inodes_count_lo) |
131 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
132 		 (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
133 }
134 
135 __u32 ext4_used_dirs_count(struct super_block *sb,
136 			      struct ext4_group_desc *bg)
137 {
138 	return le16_to_cpu(bg->bg_used_dirs_count_lo) |
139 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
140 		 (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
141 }
142 
143 __u32 ext4_itable_unused_count(struct super_block *sb,
144 			      struct ext4_group_desc *bg)
145 {
146 	return le16_to_cpu(bg->bg_itable_unused_lo) |
147 		(EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
148 		 (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
149 }
150 
151 void ext4_block_bitmap_set(struct super_block *sb,
152 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
153 {
154 	bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
155 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
156 		bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
157 }
158 
159 void ext4_inode_bitmap_set(struct super_block *sb,
160 			   struct ext4_group_desc *bg, ext4_fsblk_t blk)
161 {
162 	bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
163 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
164 		bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
165 }
166 
167 void ext4_inode_table_set(struct super_block *sb,
168 			  struct ext4_group_desc *bg, ext4_fsblk_t blk)
169 {
170 	bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
171 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
172 		bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
173 }
174 
175 void ext4_free_blks_set(struct super_block *sb,
176 			  struct ext4_group_desc *bg, __u32 count)
177 {
178 	bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
179 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
180 		bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
181 }
182 
183 void ext4_free_inodes_set(struct super_block *sb,
184 			  struct ext4_group_desc *bg, __u32 count)
185 {
186 	bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
187 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
188 		bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
189 }
190 
191 void ext4_used_dirs_set(struct super_block *sb,
192 			  struct ext4_group_desc *bg, __u32 count)
193 {
194 	bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
195 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
196 		bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
197 }
198 
199 void ext4_itable_unused_set(struct super_block *sb,
200 			  struct ext4_group_desc *bg, __u32 count)
201 {
202 	bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
203 	if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
204 		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
205 }
206 
207 
208 /* Just increment the non-pointer handle value */
209 static handle_t *ext4_get_nojournal(void)
210 {
211 	handle_t *handle = current->journal_info;
212 	unsigned long ref_cnt = (unsigned long)handle;
213 
214 	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
215 
216 	ref_cnt++;
217 	handle = (handle_t *)ref_cnt;
218 
219 	current->journal_info = handle;
220 	return handle;
221 }
222 
223 
224 /* Decrement the non-pointer handle value */
225 static void ext4_put_nojournal(handle_t *handle)
226 {
227 	unsigned long ref_cnt = (unsigned long)handle;
228 
229 	BUG_ON(ref_cnt == 0);
230 
231 	ref_cnt--;
232 	handle = (handle_t *)ref_cnt;
233 
234 	current->journal_info = handle;
235 }
236 
237 /*
238  * Wrappers for jbd2_journal_start/end.
239  *
240  * The only special thing we need to do here is to make sure that all
241  * journal_end calls result in the superblock being marked dirty, so
242  * that sync() will call the filesystem's write_super callback if
243  * appropriate.
244  */
245 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
246 {
247 	journal_t *journal;
248 
249 	if (sb->s_flags & MS_RDONLY)
250 		return ERR_PTR(-EROFS);
251 
252 	vfs_check_frozen(sb, SB_FREEZE_TRANS);
253 	/* Special case here: if the journal has aborted behind our
254 	 * backs (eg. EIO in the commit thread), then we still need to
255 	 * take the FS itself readonly cleanly. */
256 	journal = EXT4_SB(sb)->s_journal;
257 	if (journal) {
258 		if (is_journal_aborted(journal)) {
259 			ext4_abort(sb, "Detected aborted journal");
260 			return ERR_PTR(-EROFS);
261 		}
262 		return jbd2_journal_start(journal, nblocks);
263 	}
264 	return ext4_get_nojournal();
265 }
266 
267 /*
268  * The only special thing we need to do here is to make sure that all
269  * jbd2_journal_stop calls result in the superblock being marked dirty, so
270  * that sync() will call the filesystem's write_super callback if
271  * appropriate.
272  */
273 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
274 {
275 	struct super_block *sb;
276 	int err;
277 	int rc;
278 
279 	if (!ext4_handle_valid(handle)) {
280 		ext4_put_nojournal(handle);
281 		return 0;
282 	}
283 	sb = handle->h_transaction->t_journal->j_private;
284 	err = handle->h_err;
285 	rc = jbd2_journal_stop(handle);
286 
287 	if (!err)
288 		err = rc;
289 	if (err)
290 		__ext4_std_error(sb, where, line, err);
291 	return err;
292 }
293 
294 void ext4_journal_abort_handle(const char *caller, unsigned int line,
295 			       const char *err_fn, struct buffer_head *bh,
296 			       handle_t *handle, int err)
297 {
298 	char nbuf[16];
299 	const char *errstr = ext4_decode_error(NULL, err, nbuf);
300 
301 	BUG_ON(!ext4_handle_valid(handle));
302 
303 	if (bh)
304 		BUFFER_TRACE(bh, "abort");
305 
306 	if (!handle->h_err)
307 		handle->h_err = err;
308 
309 	if (is_handle_aborted(handle))
310 		return;
311 
312 	printk(KERN_ERR "%s:%d: aborting transaction: %s in %s\n",
313 	       caller, line, errstr, err_fn);
314 
315 	jbd2_journal_abort_handle(handle);
316 }
317 
318 static void __save_error_info(struct super_block *sb, const char *func,
319 			    unsigned int line)
320 {
321 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
322 
323 	EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
324 	es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
325 	es->s_last_error_time = cpu_to_le32(get_seconds());
326 	strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
327 	es->s_last_error_line = cpu_to_le32(line);
328 	if (!es->s_first_error_time) {
329 		es->s_first_error_time = es->s_last_error_time;
330 		strncpy(es->s_first_error_func, func,
331 			sizeof(es->s_first_error_func));
332 		es->s_first_error_line = cpu_to_le32(line);
333 		es->s_first_error_ino = es->s_last_error_ino;
334 		es->s_first_error_block = es->s_last_error_block;
335 	}
336 	/*
337 	 * Start the daily error reporting function if it hasn't been
338 	 * started already
339 	 */
340 	if (!es->s_error_count)
341 		mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
342 	es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
343 }
344 
345 static void save_error_info(struct super_block *sb, const char *func,
346 			    unsigned int line)
347 {
348 	__save_error_info(sb, func, line);
349 	ext4_commit_super(sb, 1);
350 }
351 
352 
353 /* Deal with the reporting of failure conditions on a filesystem such as
354  * inconsistencies detected or read IO failures.
355  *
356  * On ext2, we can store the error state of the filesystem in the
357  * superblock.  That is not possible on ext4, because we may have other
358  * write ordering constraints on the superblock which prevent us from
359  * writing it out straight away; and given that the journal is about to
360  * be aborted, we can't rely on the current, or future, transactions to
361  * write out the superblock safely.
362  *
363  * We'll just use the jbd2_journal_abort() error code to record an error in
364  * the journal instead.  On recovery, the journal will complain about
365  * that error until we've noted it down and cleared it.
366  */
367 
368 static void ext4_handle_error(struct super_block *sb)
369 {
370 	if (sb->s_flags & MS_RDONLY)
371 		return;
372 
373 	if (!test_opt(sb, ERRORS_CONT)) {
374 		journal_t *journal = EXT4_SB(sb)->s_journal;
375 
376 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
377 		if (journal)
378 			jbd2_journal_abort(journal, -EIO);
379 	}
380 	if (test_opt(sb, ERRORS_RO)) {
381 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
382 		sb->s_flags |= MS_RDONLY;
383 	}
384 	if (test_opt(sb, ERRORS_PANIC))
385 		panic("EXT4-fs (device %s): panic forced after error\n",
386 			sb->s_id);
387 }
388 
389 void __ext4_error(struct super_block *sb, const char *function,
390 		  unsigned int line, const char *fmt, ...)
391 {
392 	struct va_format vaf;
393 	va_list args;
394 
395 	va_start(args, fmt);
396 	vaf.fmt = fmt;
397 	vaf.va = &args;
398 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
399 	       sb->s_id, function, line, current->comm, &vaf);
400 	va_end(args);
401 
402 	ext4_handle_error(sb);
403 }
404 
405 void ext4_error_inode(struct inode *inode, const char *function,
406 		      unsigned int line, ext4_fsblk_t block,
407 		      const char *fmt, ...)
408 {
409 	va_list args;
410 	struct va_format vaf;
411 	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
412 
413 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
414 	es->s_last_error_block = cpu_to_le64(block);
415 	save_error_info(inode->i_sb, function, line);
416 	va_start(args, fmt);
417 	vaf.fmt = fmt;
418 	vaf.va = &args;
419 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
420 	       inode->i_sb->s_id, function, line, inode->i_ino);
421 	if (block)
422 		printk(KERN_CONT "block %llu: ", block);
423 	printk(KERN_CONT "comm %s: %pV\n", current->comm, &vaf);
424 	va_end(args);
425 
426 	ext4_handle_error(inode->i_sb);
427 }
428 
429 void ext4_error_file(struct file *file, const char *function,
430 		     unsigned int line, ext4_fsblk_t block,
431 		     const char *fmt, ...)
432 {
433 	va_list args;
434 	struct va_format vaf;
435 	struct ext4_super_block *es;
436 	struct inode *inode = file->f_dentry->d_inode;
437 	char pathname[80], *path;
438 
439 	es = EXT4_SB(inode->i_sb)->s_es;
440 	es->s_last_error_ino = cpu_to_le32(inode->i_ino);
441 	save_error_info(inode->i_sb, function, line);
442 	path = d_path(&(file->f_path), pathname, sizeof(pathname));
443 	if (IS_ERR(path))
444 		path = "(unknown)";
445 	printk(KERN_CRIT
446 	       "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
447 	       inode->i_sb->s_id, function, line, inode->i_ino);
448 	if (block)
449 		printk(KERN_CONT "block %llu: ", block);
450 	va_start(args, fmt);
451 	vaf.fmt = fmt;
452 	vaf.va = &args;
453 	printk(KERN_CONT "comm %s: path %s: %pV\n", current->comm, path, &vaf);
454 	va_end(args);
455 
456 	ext4_handle_error(inode->i_sb);
457 }
458 
459 static const char *ext4_decode_error(struct super_block *sb, int errno,
460 				     char nbuf[16])
461 {
462 	char *errstr = NULL;
463 
464 	switch (errno) {
465 	case -EIO:
466 		errstr = "IO failure";
467 		break;
468 	case -ENOMEM:
469 		errstr = "Out of memory";
470 		break;
471 	case -EROFS:
472 		if (!sb || (EXT4_SB(sb)->s_journal &&
473 			    EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
474 			errstr = "Journal has aborted";
475 		else
476 			errstr = "Readonly filesystem";
477 		break;
478 	default:
479 		/* If the caller passed in an extra buffer for unknown
480 		 * errors, textualise them now.  Else we just return
481 		 * NULL. */
482 		if (nbuf) {
483 			/* Check for truncated error codes... */
484 			if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
485 				errstr = nbuf;
486 		}
487 		break;
488 	}
489 
490 	return errstr;
491 }
492 
493 /* __ext4_std_error decodes expected errors from journaling functions
494  * automatically and invokes the appropriate error response.  */
495 
496 void __ext4_std_error(struct super_block *sb, const char *function,
497 		      unsigned int line, int errno)
498 {
499 	char nbuf[16];
500 	const char *errstr;
501 
502 	/* Special case: if the error is EROFS, and we're not already
503 	 * inside a transaction, then there's really no point in logging
504 	 * an error. */
505 	if (errno == -EROFS && journal_current_handle() == NULL &&
506 	    (sb->s_flags & MS_RDONLY))
507 		return;
508 
509 	errstr = ext4_decode_error(sb, errno, nbuf);
510 	printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
511 	       sb->s_id, function, line, errstr);
512 	save_error_info(sb, function, line);
513 
514 	ext4_handle_error(sb);
515 }
516 
517 /*
518  * ext4_abort is a much stronger failure handler than ext4_error.  The
519  * abort function may be used to deal with unrecoverable failures such
520  * as journal IO errors or ENOMEM at a critical moment in log management.
521  *
522  * We unconditionally force the filesystem into an ABORT|READONLY state,
523  * unless the error response on the fs has been set to panic in which
524  * case we take the easy way out and panic immediately.
525  */
526 
527 void __ext4_abort(struct super_block *sb, const char *function,
528 		unsigned int line, const char *fmt, ...)
529 {
530 	va_list args;
531 
532 	save_error_info(sb, function, line);
533 	va_start(args, fmt);
534 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
535 	       function, line);
536 	vprintk(fmt, args);
537 	printk("\n");
538 	va_end(args);
539 
540 	if ((sb->s_flags & MS_RDONLY) == 0) {
541 		ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
542 		sb->s_flags |= MS_RDONLY;
543 		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
544 		if (EXT4_SB(sb)->s_journal)
545 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
546 		save_error_info(sb, function, line);
547 	}
548 	if (test_opt(sb, ERRORS_PANIC))
549 		panic("EXT4-fs panic from previous error\n");
550 }
551 
552 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
553 {
554 	struct va_format vaf;
555 	va_list args;
556 
557 	va_start(args, fmt);
558 	vaf.fmt = fmt;
559 	vaf.va = &args;
560 	printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
561 	va_end(args);
562 }
563 
564 void __ext4_warning(struct super_block *sb, const char *function,
565 		    unsigned int line, const char *fmt, ...)
566 {
567 	struct va_format vaf;
568 	va_list args;
569 
570 	va_start(args, fmt);
571 	vaf.fmt = fmt;
572 	vaf.va = &args;
573 	printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
574 	       sb->s_id, function, line, &vaf);
575 	va_end(args);
576 }
577 
578 void __ext4_grp_locked_error(const char *function, unsigned int line,
579 			     struct super_block *sb, ext4_group_t grp,
580 			     unsigned long ino, ext4_fsblk_t block,
581 			     const char *fmt, ...)
582 __releases(bitlock)
583 __acquires(bitlock)
584 {
585 	struct va_format vaf;
586 	va_list args;
587 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
588 
589 	es->s_last_error_ino = cpu_to_le32(ino);
590 	es->s_last_error_block = cpu_to_le64(block);
591 	__save_error_info(sb, function, line);
592 
593 	va_start(args, fmt);
594 
595 	vaf.fmt = fmt;
596 	vaf.va = &args;
597 	printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u",
598 	       sb->s_id, function, line, grp);
599 	if (ino)
600 		printk(KERN_CONT "inode %lu: ", ino);
601 	if (block)
602 		printk(KERN_CONT "block %llu:", (unsigned long long) block);
603 	printk(KERN_CONT "%pV\n", &vaf);
604 	va_end(args);
605 
606 	if (test_opt(sb, ERRORS_CONT)) {
607 		ext4_commit_super(sb, 0);
608 		return;
609 	}
610 
611 	ext4_unlock_group(sb, grp);
612 	ext4_handle_error(sb);
613 	/*
614 	 * We only get here in the ERRORS_RO case; relocking the group
615 	 * may be dangerous, but nothing bad will happen since the
616 	 * filesystem will have already been marked read/only and the
617 	 * journal has been aborted.  We return 1 as a hint to callers
618 	 * who might what to use the return value from
619 	 * ext4_grp_locked_error() to distinguish beween the
620 	 * ERRORS_CONT and ERRORS_RO case, and perhaps return more
621 	 * aggressively from the ext4 function in question, with a
622 	 * more appropriate error code.
623 	 */
624 	ext4_lock_group(sb, grp);
625 	return;
626 }
627 
628 void ext4_update_dynamic_rev(struct super_block *sb)
629 {
630 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
631 
632 	if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
633 		return;
634 
635 	ext4_warning(sb,
636 		     "updating to rev %d because of new feature flag, "
637 		     "running e2fsck is recommended",
638 		     EXT4_DYNAMIC_REV);
639 
640 	es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
641 	es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
642 	es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
643 	/* leave es->s_feature_*compat flags alone */
644 	/* es->s_uuid will be set by e2fsck if empty */
645 
646 	/*
647 	 * The rest of the superblock fields should be zero, and if not it
648 	 * means they are likely already in use, so leave them alone.  We
649 	 * can leave it up to e2fsck to clean up any inconsistencies there.
650 	 */
651 }
652 
653 /*
654  * Open the external journal device
655  */
656 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
657 {
658 	struct block_device *bdev;
659 	char b[BDEVNAME_SIZE];
660 
661 	bdev = blkdev_get_by_dev(dev, FMODE_READ|FMODE_WRITE|FMODE_EXCL, sb);
662 	if (IS_ERR(bdev))
663 		goto fail;
664 	return bdev;
665 
666 fail:
667 	ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
668 			__bdevname(dev, b), PTR_ERR(bdev));
669 	return NULL;
670 }
671 
672 /*
673  * Release the journal device
674  */
675 static int ext4_blkdev_put(struct block_device *bdev)
676 {
677 	return blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
678 }
679 
680 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
681 {
682 	struct block_device *bdev;
683 	int ret = -ENODEV;
684 
685 	bdev = sbi->journal_bdev;
686 	if (bdev) {
687 		ret = ext4_blkdev_put(bdev);
688 		sbi->journal_bdev = NULL;
689 	}
690 	return ret;
691 }
692 
693 static inline struct inode *orphan_list_entry(struct list_head *l)
694 {
695 	return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
696 }
697 
698 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
699 {
700 	struct list_head *l;
701 
702 	ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
703 		 le32_to_cpu(sbi->s_es->s_last_orphan));
704 
705 	printk(KERN_ERR "sb_info orphan list:\n");
706 	list_for_each(l, &sbi->s_orphan) {
707 		struct inode *inode = orphan_list_entry(l);
708 		printk(KERN_ERR "  "
709 		       "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
710 		       inode->i_sb->s_id, inode->i_ino, inode,
711 		       inode->i_mode, inode->i_nlink,
712 		       NEXT_ORPHAN(inode));
713 	}
714 }
715 
716 static void ext4_put_super(struct super_block *sb)
717 {
718 	struct ext4_sb_info *sbi = EXT4_SB(sb);
719 	struct ext4_super_block *es = sbi->s_es;
720 	int i, err;
721 
722 	ext4_unregister_li_request(sb);
723 	dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
724 
725 	flush_workqueue(sbi->dio_unwritten_wq);
726 	destroy_workqueue(sbi->dio_unwritten_wq);
727 
728 	lock_super(sb);
729 	if (sb->s_dirt)
730 		ext4_commit_super(sb, 1);
731 
732 	if (sbi->s_journal) {
733 		err = jbd2_journal_destroy(sbi->s_journal);
734 		sbi->s_journal = NULL;
735 		if (err < 0)
736 			ext4_abort(sb, "Couldn't clean up the journal");
737 	}
738 
739 	del_timer(&sbi->s_err_report);
740 	ext4_release_system_zone(sb);
741 	ext4_mb_release(sb);
742 	ext4_ext_release(sb);
743 	ext4_xattr_put_super(sb);
744 
745 	if (!(sb->s_flags & MS_RDONLY)) {
746 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
747 		es->s_state = cpu_to_le16(sbi->s_mount_state);
748 		ext4_commit_super(sb, 1);
749 	}
750 	if (sbi->s_proc) {
751 		remove_proc_entry(sb->s_id, ext4_proc_root);
752 	}
753 	kobject_del(&sbi->s_kobj);
754 
755 	for (i = 0; i < sbi->s_gdb_count; i++)
756 		brelse(sbi->s_group_desc[i]);
757 	kfree(sbi->s_group_desc);
758 	if (is_vmalloc_addr(sbi->s_flex_groups))
759 		vfree(sbi->s_flex_groups);
760 	else
761 		kfree(sbi->s_flex_groups);
762 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
763 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
764 	percpu_counter_destroy(&sbi->s_dirs_counter);
765 	percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
766 	brelse(sbi->s_sbh);
767 #ifdef CONFIG_QUOTA
768 	for (i = 0; i < MAXQUOTAS; i++)
769 		kfree(sbi->s_qf_names[i]);
770 #endif
771 
772 	/* Debugging code just in case the in-memory inode orphan list
773 	 * isn't empty.  The on-disk one can be non-empty if we've
774 	 * detected an error and taken the fs readonly, but the
775 	 * in-memory list had better be clean by this point. */
776 	if (!list_empty(&sbi->s_orphan))
777 		dump_orphan_list(sb, sbi);
778 	J_ASSERT(list_empty(&sbi->s_orphan));
779 
780 	invalidate_bdev(sb->s_bdev);
781 	if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
782 		/*
783 		 * Invalidate the journal device's buffers.  We don't want them
784 		 * floating about in memory - the physical journal device may
785 		 * hotswapped, and it breaks the `ro-after' testing code.
786 		 */
787 		sync_blockdev(sbi->journal_bdev);
788 		invalidate_bdev(sbi->journal_bdev);
789 		ext4_blkdev_remove(sbi);
790 	}
791 	sb->s_fs_info = NULL;
792 	/*
793 	 * Now that we are completely done shutting down the
794 	 * superblock, we need to actually destroy the kobject.
795 	 */
796 	unlock_super(sb);
797 	kobject_put(&sbi->s_kobj);
798 	wait_for_completion(&sbi->s_kobj_unregister);
799 	kfree(sbi->s_blockgroup_lock);
800 	kfree(sbi);
801 }
802 
803 static struct kmem_cache *ext4_inode_cachep;
804 
805 /*
806  * Called inside transaction, so use GFP_NOFS
807  */
808 static struct inode *ext4_alloc_inode(struct super_block *sb)
809 {
810 	struct ext4_inode_info *ei;
811 
812 	ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
813 	if (!ei)
814 		return NULL;
815 
816 	ei->vfs_inode.i_version = 1;
817 	ei->vfs_inode.i_data.writeback_index = 0;
818 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
819 	INIT_LIST_HEAD(&ei->i_prealloc_list);
820 	spin_lock_init(&ei->i_prealloc_lock);
821 	ei->i_reserved_data_blocks = 0;
822 	ei->i_reserved_meta_blocks = 0;
823 	ei->i_allocated_meta_blocks = 0;
824 	ei->i_da_metadata_calc_len = 0;
825 	spin_lock_init(&(ei->i_block_reservation_lock));
826 #ifdef CONFIG_QUOTA
827 	ei->i_reserved_quota = 0;
828 #endif
829 	ei->jinode = NULL;
830 	INIT_LIST_HEAD(&ei->i_completed_io_list);
831 	spin_lock_init(&ei->i_completed_io_lock);
832 	ei->cur_aio_dio = NULL;
833 	ei->i_sync_tid = 0;
834 	ei->i_datasync_tid = 0;
835 	atomic_set(&ei->i_ioend_count, 0);
836 	atomic_set(&ei->i_aiodio_unwritten, 0);
837 
838 	return &ei->vfs_inode;
839 }
840 
841 static int ext4_drop_inode(struct inode *inode)
842 {
843 	int drop = generic_drop_inode(inode);
844 
845 	trace_ext4_drop_inode(inode, drop);
846 	return drop;
847 }
848 
849 static void ext4_i_callback(struct rcu_head *head)
850 {
851 	struct inode *inode = container_of(head, struct inode, i_rcu);
852 	INIT_LIST_HEAD(&inode->i_dentry);
853 	kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
854 }
855 
856 static void ext4_destroy_inode(struct inode *inode)
857 {
858 	ext4_ioend_wait(inode);
859 	if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
860 		ext4_msg(inode->i_sb, KERN_ERR,
861 			 "Inode %lu (%p): orphan list check failed!",
862 			 inode->i_ino, EXT4_I(inode));
863 		print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
864 				EXT4_I(inode), sizeof(struct ext4_inode_info),
865 				true);
866 		dump_stack();
867 	}
868 	call_rcu(&inode->i_rcu, ext4_i_callback);
869 }
870 
871 static void init_once(void *foo)
872 {
873 	struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
874 
875 	INIT_LIST_HEAD(&ei->i_orphan);
876 #ifdef CONFIG_EXT4_FS_XATTR
877 	init_rwsem(&ei->xattr_sem);
878 #endif
879 	init_rwsem(&ei->i_data_sem);
880 	inode_init_once(&ei->vfs_inode);
881 }
882 
883 static int init_inodecache(void)
884 {
885 	ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
886 					     sizeof(struct ext4_inode_info),
887 					     0, (SLAB_RECLAIM_ACCOUNT|
888 						SLAB_MEM_SPREAD),
889 					     init_once);
890 	if (ext4_inode_cachep == NULL)
891 		return -ENOMEM;
892 	return 0;
893 }
894 
895 static void destroy_inodecache(void)
896 {
897 	kmem_cache_destroy(ext4_inode_cachep);
898 }
899 
900 void ext4_clear_inode(struct inode *inode)
901 {
902 	invalidate_inode_buffers(inode);
903 	end_writeback(inode);
904 	dquot_drop(inode);
905 	ext4_discard_preallocations(inode);
906 	if (EXT4_I(inode)->jinode) {
907 		jbd2_journal_release_jbd_inode(EXT4_JOURNAL(inode),
908 					       EXT4_I(inode)->jinode);
909 		jbd2_free_inode(EXT4_I(inode)->jinode);
910 		EXT4_I(inode)->jinode = NULL;
911 	}
912 }
913 
914 static inline void ext4_show_quota_options(struct seq_file *seq,
915 					   struct super_block *sb)
916 {
917 #if defined(CONFIG_QUOTA)
918 	struct ext4_sb_info *sbi = EXT4_SB(sb);
919 
920 	if (sbi->s_jquota_fmt) {
921 		char *fmtname = "";
922 
923 		switch (sbi->s_jquota_fmt) {
924 		case QFMT_VFS_OLD:
925 			fmtname = "vfsold";
926 			break;
927 		case QFMT_VFS_V0:
928 			fmtname = "vfsv0";
929 			break;
930 		case QFMT_VFS_V1:
931 			fmtname = "vfsv1";
932 			break;
933 		}
934 		seq_printf(seq, ",jqfmt=%s", fmtname);
935 	}
936 
937 	if (sbi->s_qf_names[USRQUOTA])
938 		seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
939 
940 	if (sbi->s_qf_names[GRPQUOTA])
941 		seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
942 
943 	if (test_opt(sb, USRQUOTA))
944 		seq_puts(seq, ",usrquota");
945 
946 	if (test_opt(sb, GRPQUOTA))
947 		seq_puts(seq, ",grpquota");
948 #endif
949 }
950 
951 /*
952  * Show an option if
953  *  - it's set to a non-default value OR
954  *  - if the per-sb default is different from the global default
955  */
956 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
957 {
958 	int def_errors;
959 	unsigned long def_mount_opts;
960 	struct super_block *sb = vfs->mnt_sb;
961 	struct ext4_sb_info *sbi = EXT4_SB(sb);
962 	struct ext4_super_block *es = sbi->s_es;
963 
964 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
965 	def_errors     = le16_to_cpu(es->s_errors);
966 
967 	if (sbi->s_sb_block != 1)
968 		seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
969 	if (test_opt(sb, MINIX_DF))
970 		seq_puts(seq, ",minixdf");
971 	if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
972 		seq_puts(seq, ",grpid");
973 	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
974 		seq_puts(seq, ",nogrpid");
975 	if (sbi->s_resuid != EXT4_DEF_RESUID ||
976 	    le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
977 		seq_printf(seq, ",resuid=%u", sbi->s_resuid);
978 	}
979 	if (sbi->s_resgid != EXT4_DEF_RESGID ||
980 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
981 		seq_printf(seq, ",resgid=%u", sbi->s_resgid);
982 	}
983 	if (test_opt(sb, ERRORS_RO)) {
984 		if (def_errors == EXT4_ERRORS_PANIC ||
985 		    def_errors == EXT4_ERRORS_CONTINUE) {
986 			seq_puts(seq, ",errors=remount-ro");
987 		}
988 	}
989 	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
990 		seq_puts(seq, ",errors=continue");
991 	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
992 		seq_puts(seq, ",errors=panic");
993 	if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
994 		seq_puts(seq, ",nouid32");
995 	if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
996 		seq_puts(seq, ",debug");
997 	if (test_opt(sb, OLDALLOC))
998 		seq_puts(seq, ",oldalloc");
999 #ifdef CONFIG_EXT4_FS_XATTR
1000 	if (test_opt(sb, XATTR_USER) &&
1001 		!(def_mount_opts & EXT4_DEFM_XATTR_USER))
1002 		seq_puts(seq, ",user_xattr");
1003 	if (!test_opt(sb, XATTR_USER) &&
1004 	    (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
1005 		seq_puts(seq, ",nouser_xattr");
1006 	}
1007 #endif
1008 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1009 	if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
1010 		seq_puts(seq, ",acl");
1011 	if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
1012 		seq_puts(seq, ",noacl");
1013 #endif
1014 	if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
1015 		seq_printf(seq, ",commit=%u",
1016 			   (unsigned) (sbi->s_commit_interval / HZ));
1017 	}
1018 	if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
1019 		seq_printf(seq, ",min_batch_time=%u",
1020 			   (unsigned) sbi->s_min_batch_time);
1021 	}
1022 	if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
1023 		seq_printf(seq, ",max_batch_time=%u",
1024 			   (unsigned) sbi->s_min_batch_time);
1025 	}
1026 
1027 	/*
1028 	 * We're changing the default of barrier mount option, so
1029 	 * let's always display its mount state so it's clear what its
1030 	 * status is.
1031 	 */
1032 	seq_puts(seq, ",barrier=");
1033 	seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
1034 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
1035 		seq_puts(seq, ",journal_async_commit");
1036 	else if (test_opt(sb, JOURNAL_CHECKSUM))
1037 		seq_puts(seq, ",journal_checksum");
1038 	if (test_opt(sb, I_VERSION))
1039 		seq_puts(seq, ",i_version");
1040 	if (!test_opt(sb, DELALLOC) &&
1041 	    !(def_mount_opts & EXT4_DEFM_NODELALLOC))
1042 		seq_puts(seq, ",nodelalloc");
1043 
1044 	if (test_opt(sb, MBLK_IO_SUBMIT))
1045 		seq_puts(seq, ",mblk_io_submit");
1046 	if (sbi->s_stripe)
1047 		seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
1048 	/*
1049 	 * journal mode get enabled in different ways
1050 	 * So just print the value even if we didn't specify it
1051 	 */
1052 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1053 		seq_puts(seq, ",data=journal");
1054 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1055 		seq_puts(seq, ",data=ordered");
1056 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1057 		seq_puts(seq, ",data=writeback");
1058 
1059 	if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1060 		seq_printf(seq, ",inode_readahead_blks=%u",
1061 			   sbi->s_inode_readahead_blks);
1062 
1063 	if (test_opt(sb, DATA_ERR_ABORT))
1064 		seq_puts(seq, ",data_err=abort");
1065 
1066 	if (test_opt(sb, NO_AUTO_DA_ALLOC))
1067 		seq_puts(seq, ",noauto_da_alloc");
1068 
1069 	if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
1070 		seq_puts(seq, ",discard");
1071 
1072 	if (test_opt(sb, NOLOAD))
1073 		seq_puts(seq, ",norecovery");
1074 
1075 	if (test_opt(sb, DIOREAD_NOLOCK))
1076 		seq_puts(seq, ",dioread_nolock");
1077 
1078 	if (test_opt(sb, BLOCK_VALIDITY) &&
1079 	    !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
1080 		seq_puts(seq, ",block_validity");
1081 
1082 	if (!test_opt(sb, INIT_INODE_TABLE))
1083 		seq_puts(seq, ",noinit_inode_table");
1084 	else if (sbi->s_li_wait_mult)
1085 		seq_printf(seq, ",init_inode_table=%u",
1086 			   (unsigned) sbi->s_li_wait_mult);
1087 
1088 	ext4_show_quota_options(seq, sb);
1089 
1090 	return 0;
1091 }
1092 
1093 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1094 					u64 ino, u32 generation)
1095 {
1096 	struct inode *inode;
1097 
1098 	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1099 		return ERR_PTR(-ESTALE);
1100 	if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1101 		return ERR_PTR(-ESTALE);
1102 
1103 	/* iget isn't really right if the inode is currently unallocated!!
1104 	 *
1105 	 * ext4_read_inode will return a bad_inode if the inode had been
1106 	 * deleted, so we should be safe.
1107 	 *
1108 	 * Currently we don't know the generation for parent directory, so
1109 	 * a generation of 0 means "accept any"
1110 	 */
1111 	inode = ext4_iget(sb, ino);
1112 	if (IS_ERR(inode))
1113 		return ERR_CAST(inode);
1114 	if (generation && inode->i_generation != generation) {
1115 		iput(inode);
1116 		return ERR_PTR(-ESTALE);
1117 	}
1118 
1119 	return inode;
1120 }
1121 
1122 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1123 					int fh_len, int fh_type)
1124 {
1125 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1126 				    ext4_nfs_get_inode);
1127 }
1128 
1129 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1130 					int fh_len, int fh_type)
1131 {
1132 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1133 				    ext4_nfs_get_inode);
1134 }
1135 
1136 /*
1137  * Try to release metadata pages (indirect blocks, directories) which are
1138  * mapped via the block device.  Since these pages could have journal heads
1139  * which would prevent try_to_free_buffers() from freeing them, we must use
1140  * jbd2 layer's try_to_free_buffers() function to release them.
1141  */
1142 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1143 				 gfp_t wait)
1144 {
1145 	journal_t *journal = EXT4_SB(sb)->s_journal;
1146 
1147 	WARN_ON(PageChecked(page));
1148 	if (!page_has_buffers(page))
1149 		return 0;
1150 	if (journal)
1151 		return jbd2_journal_try_to_free_buffers(journal, page,
1152 							wait & ~__GFP_WAIT);
1153 	return try_to_free_buffers(page);
1154 }
1155 
1156 #ifdef CONFIG_QUOTA
1157 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1158 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1159 
1160 static int ext4_write_dquot(struct dquot *dquot);
1161 static int ext4_acquire_dquot(struct dquot *dquot);
1162 static int ext4_release_dquot(struct dquot *dquot);
1163 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1164 static int ext4_write_info(struct super_block *sb, int type);
1165 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1166 			 struct path *path);
1167 static int ext4_quota_off(struct super_block *sb, int type);
1168 static int ext4_quota_on_mount(struct super_block *sb, int type);
1169 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1170 			       size_t len, loff_t off);
1171 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1172 				const char *data, size_t len, loff_t off);
1173 
1174 static const struct dquot_operations ext4_quota_operations = {
1175 #ifdef CONFIG_QUOTA
1176 	.get_reserved_space = ext4_get_reserved_space,
1177 #endif
1178 	.write_dquot	= ext4_write_dquot,
1179 	.acquire_dquot	= ext4_acquire_dquot,
1180 	.release_dquot	= ext4_release_dquot,
1181 	.mark_dirty	= ext4_mark_dquot_dirty,
1182 	.write_info	= ext4_write_info,
1183 	.alloc_dquot	= dquot_alloc,
1184 	.destroy_dquot	= dquot_destroy,
1185 };
1186 
1187 static const struct quotactl_ops ext4_qctl_operations = {
1188 	.quota_on	= ext4_quota_on,
1189 	.quota_off	= ext4_quota_off,
1190 	.quota_sync	= dquot_quota_sync,
1191 	.get_info	= dquot_get_dqinfo,
1192 	.set_info	= dquot_set_dqinfo,
1193 	.get_dqblk	= dquot_get_dqblk,
1194 	.set_dqblk	= dquot_set_dqblk
1195 };
1196 #endif
1197 
1198 static const struct super_operations ext4_sops = {
1199 	.alloc_inode	= ext4_alloc_inode,
1200 	.destroy_inode	= ext4_destroy_inode,
1201 	.write_inode	= ext4_write_inode,
1202 	.dirty_inode	= ext4_dirty_inode,
1203 	.drop_inode	= ext4_drop_inode,
1204 	.evict_inode	= ext4_evict_inode,
1205 	.put_super	= ext4_put_super,
1206 	.sync_fs	= ext4_sync_fs,
1207 	.freeze_fs	= ext4_freeze,
1208 	.unfreeze_fs	= ext4_unfreeze,
1209 	.statfs		= ext4_statfs,
1210 	.remount_fs	= ext4_remount,
1211 	.show_options	= ext4_show_options,
1212 #ifdef CONFIG_QUOTA
1213 	.quota_read	= ext4_quota_read,
1214 	.quota_write	= ext4_quota_write,
1215 #endif
1216 	.bdev_try_to_free_page = bdev_try_to_free_page,
1217 };
1218 
1219 static const struct super_operations ext4_nojournal_sops = {
1220 	.alloc_inode	= ext4_alloc_inode,
1221 	.destroy_inode	= ext4_destroy_inode,
1222 	.write_inode	= ext4_write_inode,
1223 	.dirty_inode	= ext4_dirty_inode,
1224 	.drop_inode	= ext4_drop_inode,
1225 	.evict_inode	= ext4_evict_inode,
1226 	.write_super	= ext4_write_super,
1227 	.put_super	= ext4_put_super,
1228 	.statfs		= ext4_statfs,
1229 	.remount_fs	= ext4_remount,
1230 	.show_options	= ext4_show_options,
1231 #ifdef CONFIG_QUOTA
1232 	.quota_read	= ext4_quota_read,
1233 	.quota_write	= ext4_quota_write,
1234 #endif
1235 	.bdev_try_to_free_page = bdev_try_to_free_page,
1236 };
1237 
1238 static const struct export_operations ext4_export_ops = {
1239 	.fh_to_dentry = ext4_fh_to_dentry,
1240 	.fh_to_parent = ext4_fh_to_parent,
1241 	.get_parent = ext4_get_parent,
1242 };
1243 
1244 enum {
1245 	Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1246 	Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1247 	Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1248 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1249 	Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1250 	Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1251 	Opt_journal_update, Opt_journal_dev,
1252 	Opt_journal_checksum, Opt_journal_async_commit,
1253 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1254 	Opt_data_err_abort, Opt_data_err_ignore,
1255 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1256 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1257 	Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1258 	Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1259 	Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1260 	Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1261 	Opt_inode_readahead_blks, Opt_journal_ioprio,
1262 	Opt_dioread_nolock, Opt_dioread_lock,
1263 	Opt_discard, Opt_nodiscard,
1264 	Opt_init_inode_table, Opt_noinit_inode_table,
1265 };
1266 
1267 static const match_table_t tokens = {
1268 	{Opt_bsd_df, "bsddf"},
1269 	{Opt_minix_df, "minixdf"},
1270 	{Opt_grpid, "grpid"},
1271 	{Opt_grpid, "bsdgroups"},
1272 	{Opt_nogrpid, "nogrpid"},
1273 	{Opt_nogrpid, "sysvgroups"},
1274 	{Opt_resgid, "resgid=%u"},
1275 	{Opt_resuid, "resuid=%u"},
1276 	{Opt_sb, "sb=%u"},
1277 	{Opt_err_cont, "errors=continue"},
1278 	{Opt_err_panic, "errors=panic"},
1279 	{Opt_err_ro, "errors=remount-ro"},
1280 	{Opt_nouid32, "nouid32"},
1281 	{Opt_debug, "debug"},
1282 	{Opt_oldalloc, "oldalloc"},
1283 	{Opt_orlov, "orlov"},
1284 	{Opt_user_xattr, "user_xattr"},
1285 	{Opt_nouser_xattr, "nouser_xattr"},
1286 	{Opt_acl, "acl"},
1287 	{Opt_noacl, "noacl"},
1288 	{Opt_noload, "noload"},
1289 	{Opt_noload, "norecovery"},
1290 	{Opt_nobh, "nobh"},
1291 	{Opt_bh, "bh"},
1292 	{Opt_commit, "commit=%u"},
1293 	{Opt_min_batch_time, "min_batch_time=%u"},
1294 	{Opt_max_batch_time, "max_batch_time=%u"},
1295 	{Opt_journal_update, "journal=update"},
1296 	{Opt_journal_dev, "journal_dev=%u"},
1297 	{Opt_journal_checksum, "journal_checksum"},
1298 	{Opt_journal_async_commit, "journal_async_commit"},
1299 	{Opt_abort, "abort"},
1300 	{Opt_data_journal, "data=journal"},
1301 	{Opt_data_ordered, "data=ordered"},
1302 	{Opt_data_writeback, "data=writeback"},
1303 	{Opt_data_err_abort, "data_err=abort"},
1304 	{Opt_data_err_ignore, "data_err=ignore"},
1305 	{Opt_offusrjquota, "usrjquota="},
1306 	{Opt_usrjquota, "usrjquota=%s"},
1307 	{Opt_offgrpjquota, "grpjquota="},
1308 	{Opt_grpjquota, "grpjquota=%s"},
1309 	{Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1310 	{Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1311 	{Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1312 	{Opt_grpquota, "grpquota"},
1313 	{Opt_noquota, "noquota"},
1314 	{Opt_quota, "quota"},
1315 	{Opt_usrquota, "usrquota"},
1316 	{Opt_barrier, "barrier=%u"},
1317 	{Opt_barrier, "barrier"},
1318 	{Opt_nobarrier, "nobarrier"},
1319 	{Opt_i_version, "i_version"},
1320 	{Opt_stripe, "stripe=%u"},
1321 	{Opt_resize, "resize"},
1322 	{Opt_delalloc, "delalloc"},
1323 	{Opt_nodelalloc, "nodelalloc"},
1324 	{Opt_mblk_io_submit, "mblk_io_submit"},
1325 	{Opt_nomblk_io_submit, "nomblk_io_submit"},
1326 	{Opt_block_validity, "block_validity"},
1327 	{Opt_noblock_validity, "noblock_validity"},
1328 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1329 	{Opt_journal_ioprio, "journal_ioprio=%u"},
1330 	{Opt_auto_da_alloc, "auto_da_alloc=%u"},
1331 	{Opt_auto_da_alloc, "auto_da_alloc"},
1332 	{Opt_noauto_da_alloc, "noauto_da_alloc"},
1333 	{Opt_dioread_nolock, "dioread_nolock"},
1334 	{Opt_dioread_lock, "dioread_lock"},
1335 	{Opt_discard, "discard"},
1336 	{Opt_nodiscard, "nodiscard"},
1337 	{Opt_init_inode_table, "init_itable=%u"},
1338 	{Opt_init_inode_table, "init_itable"},
1339 	{Opt_noinit_inode_table, "noinit_itable"},
1340 	{Opt_err, NULL},
1341 };
1342 
1343 static ext4_fsblk_t get_sb_block(void **data)
1344 {
1345 	ext4_fsblk_t	sb_block;
1346 	char		*options = (char *) *data;
1347 
1348 	if (!options || strncmp(options, "sb=", 3) != 0)
1349 		return 1;	/* Default location */
1350 
1351 	options += 3;
1352 	/* TODO: use simple_strtoll with >32bit ext4 */
1353 	sb_block = simple_strtoul(options, &options, 0);
1354 	if (*options && *options != ',') {
1355 		printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1356 		       (char *) *data);
1357 		return 1;
1358 	}
1359 	if (*options == ',')
1360 		options++;
1361 	*data = (void *) options;
1362 
1363 	return sb_block;
1364 }
1365 
1366 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1367 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1368 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1369 
1370 #ifdef CONFIG_QUOTA
1371 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1372 {
1373 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1374 	char *qname;
1375 
1376 	if (sb_any_quota_loaded(sb) &&
1377 		!sbi->s_qf_names[qtype]) {
1378 		ext4_msg(sb, KERN_ERR,
1379 			"Cannot change journaled "
1380 			"quota options when quota turned on");
1381 		return 0;
1382 	}
1383 	qname = match_strdup(args);
1384 	if (!qname) {
1385 		ext4_msg(sb, KERN_ERR,
1386 			"Not enough memory for storing quotafile name");
1387 		return 0;
1388 	}
1389 	if (sbi->s_qf_names[qtype] &&
1390 		strcmp(sbi->s_qf_names[qtype], qname)) {
1391 		ext4_msg(sb, KERN_ERR,
1392 			"%s quota file already specified", QTYPE2NAME(qtype));
1393 		kfree(qname);
1394 		return 0;
1395 	}
1396 	sbi->s_qf_names[qtype] = qname;
1397 	if (strchr(sbi->s_qf_names[qtype], '/')) {
1398 		ext4_msg(sb, KERN_ERR,
1399 			"quotafile must be on filesystem root");
1400 		kfree(sbi->s_qf_names[qtype]);
1401 		sbi->s_qf_names[qtype] = NULL;
1402 		return 0;
1403 	}
1404 	set_opt(sb, QUOTA);
1405 	return 1;
1406 }
1407 
1408 static int clear_qf_name(struct super_block *sb, int qtype)
1409 {
1410 
1411 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1412 
1413 	if (sb_any_quota_loaded(sb) &&
1414 		sbi->s_qf_names[qtype]) {
1415 		ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1416 			" when quota turned on");
1417 		return 0;
1418 	}
1419 	/*
1420 	 * The space will be released later when all options are confirmed
1421 	 * to be correct
1422 	 */
1423 	sbi->s_qf_names[qtype] = NULL;
1424 	return 1;
1425 }
1426 #endif
1427 
1428 static int parse_options(char *options, struct super_block *sb,
1429 			 unsigned long *journal_devnum,
1430 			 unsigned int *journal_ioprio,
1431 			 ext4_fsblk_t *n_blocks_count, int is_remount)
1432 {
1433 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1434 	char *p;
1435 	substring_t args[MAX_OPT_ARGS];
1436 	int data_opt = 0;
1437 	int option;
1438 #ifdef CONFIG_QUOTA
1439 	int qfmt;
1440 #endif
1441 
1442 	if (!options)
1443 		return 1;
1444 
1445 	while ((p = strsep(&options, ",")) != NULL) {
1446 		int token;
1447 		if (!*p)
1448 			continue;
1449 
1450 		/*
1451 		 * Initialize args struct so we know whether arg was
1452 		 * found; some options take optional arguments.
1453 		 */
1454 		args[0].to = args[0].from = 0;
1455 		token = match_token(p, tokens, args);
1456 		switch (token) {
1457 		case Opt_bsd_df:
1458 			ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1459 			clear_opt(sb, MINIX_DF);
1460 			break;
1461 		case Opt_minix_df:
1462 			ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1463 			set_opt(sb, MINIX_DF);
1464 
1465 			break;
1466 		case Opt_grpid:
1467 			ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1468 			set_opt(sb, GRPID);
1469 
1470 			break;
1471 		case Opt_nogrpid:
1472 			ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1473 			clear_opt(sb, GRPID);
1474 
1475 			break;
1476 		case Opt_resuid:
1477 			if (match_int(&args[0], &option))
1478 				return 0;
1479 			sbi->s_resuid = option;
1480 			break;
1481 		case Opt_resgid:
1482 			if (match_int(&args[0], &option))
1483 				return 0;
1484 			sbi->s_resgid = option;
1485 			break;
1486 		case Opt_sb:
1487 			/* handled by get_sb_block() instead of here */
1488 			/* *sb_block = match_int(&args[0]); */
1489 			break;
1490 		case Opt_err_panic:
1491 			clear_opt(sb, ERRORS_CONT);
1492 			clear_opt(sb, ERRORS_RO);
1493 			set_opt(sb, ERRORS_PANIC);
1494 			break;
1495 		case Opt_err_ro:
1496 			clear_opt(sb, ERRORS_CONT);
1497 			clear_opt(sb, ERRORS_PANIC);
1498 			set_opt(sb, ERRORS_RO);
1499 			break;
1500 		case Opt_err_cont:
1501 			clear_opt(sb, ERRORS_RO);
1502 			clear_opt(sb, ERRORS_PANIC);
1503 			set_opt(sb, ERRORS_CONT);
1504 			break;
1505 		case Opt_nouid32:
1506 			set_opt(sb, NO_UID32);
1507 			break;
1508 		case Opt_debug:
1509 			set_opt(sb, DEBUG);
1510 			break;
1511 		case Opt_oldalloc:
1512 			set_opt(sb, OLDALLOC);
1513 			break;
1514 		case Opt_orlov:
1515 			clear_opt(sb, OLDALLOC);
1516 			break;
1517 #ifdef CONFIG_EXT4_FS_XATTR
1518 		case Opt_user_xattr:
1519 			set_opt(sb, XATTR_USER);
1520 			break;
1521 		case Opt_nouser_xattr:
1522 			clear_opt(sb, XATTR_USER);
1523 			break;
1524 #else
1525 		case Opt_user_xattr:
1526 		case Opt_nouser_xattr:
1527 			ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1528 			break;
1529 #endif
1530 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1531 		case Opt_acl:
1532 			set_opt(sb, POSIX_ACL);
1533 			break;
1534 		case Opt_noacl:
1535 			clear_opt(sb, POSIX_ACL);
1536 			break;
1537 #else
1538 		case Opt_acl:
1539 		case Opt_noacl:
1540 			ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1541 			break;
1542 #endif
1543 		case Opt_journal_update:
1544 			/* @@@ FIXME */
1545 			/* Eventually we will want to be able to create
1546 			   a journal file here.  For now, only allow the
1547 			   user to specify an existing inode to be the
1548 			   journal file. */
1549 			if (is_remount) {
1550 				ext4_msg(sb, KERN_ERR,
1551 					 "Cannot specify journal on remount");
1552 				return 0;
1553 			}
1554 			set_opt(sb, UPDATE_JOURNAL);
1555 			break;
1556 		case Opt_journal_dev:
1557 			if (is_remount) {
1558 				ext4_msg(sb, KERN_ERR,
1559 					"Cannot specify journal on remount");
1560 				return 0;
1561 			}
1562 			if (match_int(&args[0], &option))
1563 				return 0;
1564 			*journal_devnum = option;
1565 			break;
1566 		case Opt_journal_checksum:
1567 			set_opt(sb, JOURNAL_CHECKSUM);
1568 			break;
1569 		case Opt_journal_async_commit:
1570 			set_opt(sb, JOURNAL_ASYNC_COMMIT);
1571 			set_opt(sb, JOURNAL_CHECKSUM);
1572 			break;
1573 		case Opt_noload:
1574 			set_opt(sb, NOLOAD);
1575 			break;
1576 		case Opt_commit:
1577 			if (match_int(&args[0], &option))
1578 				return 0;
1579 			if (option < 0)
1580 				return 0;
1581 			if (option == 0)
1582 				option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1583 			sbi->s_commit_interval = HZ * option;
1584 			break;
1585 		case Opt_max_batch_time:
1586 			if (match_int(&args[0], &option))
1587 				return 0;
1588 			if (option < 0)
1589 				return 0;
1590 			if (option == 0)
1591 				option = EXT4_DEF_MAX_BATCH_TIME;
1592 			sbi->s_max_batch_time = option;
1593 			break;
1594 		case Opt_min_batch_time:
1595 			if (match_int(&args[0], &option))
1596 				return 0;
1597 			if (option < 0)
1598 				return 0;
1599 			sbi->s_min_batch_time = option;
1600 			break;
1601 		case Opt_data_journal:
1602 			data_opt = EXT4_MOUNT_JOURNAL_DATA;
1603 			goto datacheck;
1604 		case Opt_data_ordered:
1605 			data_opt = EXT4_MOUNT_ORDERED_DATA;
1606 			goto datacheck;
1607 		case Opt_data_writeback:
1608 			data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1609 		datacheck:
1610 			if (is_remount) {
1611 				if (test_opt(sb, DATA_FLAGS) != data_opt) {
1612 					ext4_msg(sb, KERN_ERR,
1613 						"Cannot change data mode on remount");
1614 					return 0;
1615 				}
1616 			} else {
1617 				clear_opt(sb, DATA_FLAGS);
1618 				sbi->s_mount_opt |= data_opt;
1619 			}
1620 			break;
1621 		case Opt_data_err_abort:
1622 			set_opt(sb, DATA_ERR_ABORT);
1623 			break;
1624 		case Opt_data_err_ignore:
1625 			clear_opt(sb, DATA_ERR_ABORT);
1626 			break;
1627 #ifdef CONFIG_QUOTA
1628 		case Opt_usrjquota:
1629 			if (!set_qf_name(sb, USRQUOTA, &args[0]))
1630 				return 0;
1631 			break;
1632 		case Opt_grpjquota:
1633 			if (!set_qf_name(sb, GRPQUOTA, &args[0]))
1634 				return 0;
1635 			break;
1636 		case Opt_offusrjquota:
1637 			if (!clear_qf_name(sb, USRQUOTA))
1638 				return 0;
1639 			break;
1640 		case Opt_offgrpjquota:
1641 			if (!clear_qf_name(sb, GRPQUOTA))
1642 				return 0;
1643 			break;
1644 
1645 		case Opt_jqfmt_vfsold:
1646 			qfmt = QFMT_VFS_OLD;
1647 			goto set_qf_format;
1648 		case Opt_jqfmt_vfsv0:
1649 			qfmt = QFMT_VFS_V0;
1650 			goto set_qf_format;
1651 		case Opt_jqfmt_vfsv1:
1652 			qfmt = QFMT_VFS_V1;
1653 set_qf_format:
1654 			if (sb_any_quota_loaded(sb) &&
1655 			    sbi->s_jquota_fmt != qfmt) {
1656 				ext4_msg(sb, KERN_ERR, "Cannot change "
1657 					"journaled quota options when "
1658 					"quota turned on");
1659 				return 0;
1660 			}
1661 			sbi->s_jquota_fmt = qfmt;
1662 			break;
1663 		case Opt_quota:
1664 		case Opt_usrquota:
1665 			set_opt(sb, QUOTA);
1666 			set_opt(sb, USRQUOTA);
1667 			break;
1668 		case Opt_grpquota:
1669 			set_opt(sb, QUOTA);
1670 			set_opt(sb, GRPQUOTA);
1671 			break;
1672 		case Opt_noquota:
1673 			if (sb_any_quota_loaded(sb)) {
1674 				ext4_msg(sb, KERN_ERR, "Cannot change quota "
1675 					"options when quota turned on");
1676 				return 0;
1677 			}
1678 			clear_opt(sb, QUOTA);
1679 			clear_opt(sb, USRQUOTA);
1680 			clear_opt(sb, GRPQUOTA);
1681 			break;
1682 #else
1683 		case Opt_quota:
1684 		case Opt_usrquota:
1685 		case Opt_grpquota:
1686 			ext4_msg(sb, KERN_ERR,
1687 				"quota options not supported");
1688 			break;
1689 		case Opt_usrjquota:
1690 		case Opt_grpjquota:
1691 		case Opt_offusrjquota:
1692 		case Opt_offgrpjquota:
1693 		case Opt_jqfmt_vfsold:
1694 		case Opt_jqfmt_vfsv0:
1695 		case Opt_jqfmt_vfsv1:
1696 			ext4_msg(sb, KERN_ERR,
1697 				"journaled quota options not supported");
1698 			break;
1699 		case Opt_noquota:
1700 			break;
1701 #endif
1702 		case Opt_abort:
1703 			sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1704 			break;
1705 		case Opt_nobarrier:
1706 			clear_opt(sb, BARRIER);
1707 			break;
1708 		case Opt_barrier:
1709 			if (args[0].from) {
1710 				if (match_int(&args[0], &option))
1711 					return 0;
1712 			} else
1713 				option = 1;	/* No argument, default to 1 */
1714 			if (option)
1715 				set_opt(sb, BARRIER);
1716 			else
1717 				clear_opt(sb, BARRIER);
1718 			break;
1719 		case Opt_ignore:
1720 			break;
1721 		case Opt_resize:
1722 			if (!is_remount) {
1723 				ext4_msg(sb, KERN_ERR,
1724 					"resize option only available "
1725 					"for remount");
1726 				return 0;
1727 			}
1728 			if (match_int(&args[0], &option) != 0)
1729 				return 0;
1730 			*n_blocks_count = option;
1731 			break;
1732 		case Opt_nobh:
1733 			ext4_msg(sb, KERN_WARNING,
1734 				 "Ignoring deprecated nobh option");
1735 			break;
1736 		case Opt_bh:
1737 			ext4_msg(sb, KERN_WARNING,
1738 				 "Ignoring deprecated bh option");
1739 			break;
1740 		case Opt_i_version:
1741 			set_opt(sb, I_VERSION);
1742 			sb->s_flags |= MS_I_VERSION;
1743 			break;
1744 		case Opt_nodelalloc:
1745 			clear_opt(sb, DELALLOC);
1746 			break;
1747 		case Opt_mblk_io_submit:
1748 			set_opt(sb, MBLK_IO_SUBMIT);
1749 			break;
1750 		case Opt_nomblk_io_submit:
1751 			clear_opt(sb, MBLK_IO_SUBMIT);
1752 			break;
1753 		case Opt_stripe:
1754 			if (match_int(&args[0], &option))
1755 				return 0;
1756 			if (option < 0)
1757 				return 0;
1758 			sbi->s_stripe = option;
1759 			break;
1760 		case Opt_delalloc:
1761 			set_opt(sb, DELALLOC);
1762 			break;
1763 		case Opt_block_validity:
1764 			set_opt(sb, BLOCK_VALIDITY);
1765 			break;
1766 		case Opt_noblock_validity:
1767 			clear_opt(sb, BLOCK_VALIDITY);
1768 			break;
1769 		case Opt_inode_readahead_blks:
1770 			if (match_int(&args[0], &option))
1771 				return 0;
1772 			if (option < 0 || option > (1 << 30))
1773 				return 0;
1774 			if (!is_power_of_2(option)) {
1775 				ext4_msg(sb, KERN_ERR,
1776 					 "EXT4-fs: inode_readahead_blks"
1777 					 " must be a power of 2");
1778 				return 0;
1779 			}
1780 			sbi->s_inode_readahead_blks = option;
1781 			break;
1782 		case Opt_journal_ioprio:
1783 			if (match_int(&args[0], &option))
1784 				return 0;
1785 			if (option < 0 || option > 7)
1786 				break;
1787 			*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1788 							    option);
1789 			break;
1790 		case Opt_noauto_da_alloc:
1791 			set_opt(sb, NO_AUTO_DA_ALLOC);
1792 			break;
1793 		case Opt_auto_da_alloc:
1794 			if (args[0].from) {
1795 				if (match_int(&args[0], &option))
1796 					return 0;
1797 			} else
1798 				option = 1;	/* No argument, default to 1 */
1799 			if (option)
1800 				clear_opt(sb, NO_AUTO_DA_ALLOC);
1801 			else
1802 				set_opt(sb,NO_AUTO_DA_ALLOC);
1803 			break;
1804 		case Opt_discard:
1805 			set_opt(sb, DISCARD);
1806 			break;
1807 		case Opt_nodiscard:
1808 			clear_opt(sb, DISCARD);
1809 			break;
1810 		case Opt_dioread_nolock:
1811 			set_opt(sb, DIOREAD_NOLOCK);
1812 			break;
1813 		case Opt_dioread_lock:
1814 			clear_opt(sb, DIOREAD_NOLOCK);
1815 			break;
1816 		case Opt_init_inode_table:
1817 			set_opt(sb, INIT_INODE_TABLE);
1818 			if (args[0].from) {
1819 				if (match_int(&args[0], &option))
1820 					return 0;
1821 			} else
1822 				option = EXT4_DEF_LI_WAIT_MULT;
1823 			if (option < 0)
1824 				return 0;
1825 			sbi->s_li_wait_mult = option;
1826 			break;
1827 		case Opt_noinit_inode_table:
1828 			clear_opt(sb, INIT_INODE_TABLE);
1829 			break;
1830 		default:
1831 			ext4_msg(sb, KERN_ERR,
1832 			       "Unrecognized mount option \"%s\" "
1833 			       "or missing value", p);
1834 			return 0;
1835 		}
1836 	}
1837 #ifdef CONFIG_QUOTA
1838 	if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1839 		if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1840 			clear_opt(sb, USRQUOTA);
1841 
1842 		if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1843 			clear_opt(sb, GRPQUOTA);
1844 
1845 		if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1846 			ext4_msg(sb, KERN_ERR, "old and new quota "
1847 					"format mixing");
1848 			return 0;
1849 		}
1850 
1851 		if (!sbi->s_jquota_fmt) {
1852 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1853 					"not specified");
1854 			return 0;
1855 		}
1856 	} else {
1857 		if (sbi->s_jquota_fmt) {
1858 			ext4_msg(sb, KERN_ERR, "journaled quota format "
1859 					"specified with no journaling "
1860 					"enabled");
1861 			return 0;
1862 		}
1863 	}
1864 #endif
1865 	return 1;
1866 }
1867 
1868 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1869 			    int read_only)
1870 {
1871 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1872 	int res = 0;
1873 
1874 	if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1875 		ext4_msg(sb, KERN_ERR, "revision level too high, "
1876 			 "forcing read-only mode");
1877 		res = MS_RDONLY;
1878 	}
1879 	if (read_only)
1880 		return res;
1881 	if (!(sbi->s_mount_state & EXT4_VALID_FS))
1882 		ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1883 			 "running e2fsck is recommended");
1884 	else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1885 		ext4_msg(sb, KERN_WARNING,
1886 			 "warning: mounting fs with errors, "
1887 			 "running e2fsck is recommended");
1888 	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1889 		 le16_to_cpu(es->s_mnt_count) >=
1890 		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1891 		ext4_msg(sb, KERN_WARNING,
1892 			 "warning: maximal mount count reached, "
1893 			 "running e2fsck is recommended");
1894 	else if (le32_to_cpu(es->s_checkinterval) &&
1895 		(le32_to_cpu(es->s_lastcheck) +
1896 			le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1897 		ext4_msg(sb, KERN_WARNING,
1898 			 "warning: checktime reached, "
1899 			 "running e2fsck is recommended");
1900 	if (!sbi->s_journal)
1901 		es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1902 	if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1903 		es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1904 	le16_add_cpu(&es->s_mnt_count, 1);
1905 	es->s_mtime = cpu_to_le32(get_seconds());
1906 	ext4_update_dynamic_rev(sb);
1907 	if (sbi->s_journal)
1908 		EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1909 
1910 	ext4_commit_super(sb, 1);
1911 	if (test_opt(sb, DEBUG))
1912 		printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1913 				"bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1914 			sb->s_blocksize,
1915 			sbi->s_groups_count,
1916 			EXT4_BLOCKS_PER_GROUP(sb),
1917 			EXT4_INODES_PER_GROUP(sb),
1918 			sbi->s_mount_opt, sbi->s_mount_opt2);
1919 
1920 	return res;
1921 }
1922 
1923 static int ext4_fill_flex_info(struct super_block *sb)
1924 {
1925 	struct ext4_sb_info *sbi = EXT4_SB(sb);
1926 	struct ext4_group_desc *gdp = NULL;
1927 	ext4_group_t flex_group_count;
1928 	ext4_group_t flex_group;
1929 	int groups_per_flex = 0;
1930 	size_t size;
1931 	int i;
1932 
1933 	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1934 	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1935 
1936 	if (groups_per_flex < 2) {
1937 		sbi->s_log_groups_per_flex = 0;
1938 		return 1;
1939 	}
1940 
1941 	/* We allocate both existing and potentially added groups */
1942 	flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1943 			((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1944 			      EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1945 	size = flex_group_count * sizeof(struct flex_groups);
1946 	sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1947 	if (sbi->s_flex_groups == NULL) {
1948 		sbi->s_flex_groups = vzalloc(size);
1949 		if (sbi->s_flex_groups == NULL) {
1950 			ext4_msg(sb, KERN_ERR,
1951 				 "not enough memory for %u flex groups",
1952 				 flex_group_count);
1953 			goto failed;
1954 		}
1955 	}
1956 
1957 	for (i = 0; i < sbi->s_groups_count; i++) {
1958 		gdp = ext4_get_group_desc(sb, i, NULL);
1959 
1960 		flex_group = ext4_flex_group(sbi, i);
1961 		atomic_add(ext4_free_inodes_count(sb, gdp),
1962 			   &sbi->s_flex_groups[flex_group].free_inodes);
1963 		atomic_add(ext4_free_blks_count(sb, gdp),
1964 			   &sbi->s_flex_groups[flex_group].free_blocks);
1965 		atomic_add(ext4_used_dirs_count(sb, gdp),
1966 			   &sbi->s_flex_groups[flex_group].used_dirs);
1967 	}
1968 
1969 	return 1;
1970 failed:
1971 	return 0;
1972 }
1973 
1974 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1975 			    struct ext4_group_desc *gdp)
1976 {
1977 	__u16 crc = 0;
1978 
1979 	if (sbi->s_es->s_feature_ro_compat &
1980 	    cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1981 		int offset = offsetof(struct ext4_group_desc, bg_checksum);
1982 		__le32 le_group = cpu_to_le32(block_group);
1983 
1984 		crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1985 		crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1986 		crc = crc16(crc, (__u8 *)gdp, offset);
1987 		offset += sizeof(gdp->bg_checksum); /* skip checksum */
1988 		/* for checksum of struct ext4_group_desc do the rest...*/
1989 		if ((sbi->s_es->s_feature_incompat &
1990 		     cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1991 		    offset < le16_to_cpu(sbi->s_es->s_desc_size))
1992 			crc = crc16(crc, (__u8 *)gdp + offset,
1993 				    le16_to_cpu(sbi->s_es->s_desc_size) -
1994 					offset);
1995 	}
1996 
1997 	return cpu_to_le16(crc);
1998 }
1999 
2000 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
2001 				struct ext4_group_desc *gdp)
2002 {
2003 	if ((sbi->s_es->s_feature_ro_compat &
2004 	     cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
2005 	    (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
2006 		return 0;
2007 
2008 	return 1;
2009 }
2010 
2011 /* Called at mount-time, super-block is locked */
2012 static int ext4_check_descriptors(struct super_block *sb,
2013 				  ext4_group_t *first_not_zeroed)
2014 {
2015 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2016 	ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2017 	ext4_fsblk_t last_block;
2018 	ext4_fsblk_t block_bitmap;
2019 	ext4_fsblk_t inode_bitmap;
2020 	ext4_fsblk_t inode_table;
2021 	int flexbg_flag = 0;
2022 	ext4_group_t i, grp = sbi->s_groups_count;
2023 
2024 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2025 		flexbg_flag = 1;
2026 
2027 	ext4_debug("Checking group descriptors");
2028 
2029 	for (i = 0; i < sbi->s_groups_count; i++) {
2030 		struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2031 
2032 		if (i == sbi->s_groups_count - 1 || flexbg_flag)
2033 			last_block = ext4_blocks_count(sbi->s_es) - 1;
2034 		else
2035 			last_block = first_block +
2036 				(EXT4_BLOCKS_PER_GROUP(sb) - 1);
2037 
2038 		if ((grp == sbi->s_groups_count) &&
2039 		   !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2040 			grp = i;
2041 
2042 		block_bitmap = ext4_block_bitmap(sb, gdp);
2043 		if (block_bitmap < first_block || block_bitmap > last_block) {
2044 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2045 			       "Block bitmap for group %u not in group "
2046 			       "(block %llu)!", i, block_bitmap);
2047 			return 0;
2048 		}
2049 		inode_bitmap = ext4_inode_bitmap(sb, gdp);
2050 		if (inode_bitmap < first_block || inode_bitmap > last_block) {
2051 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2052 			       "Inode bitmap for group %u not in group "
2053 			       "(block %llu)!", i, inode_bitmap);
2054 			return 0;
2055 		}
2056 		inode_table = ext4_inode_table(sb, gdp);
2057 		if (inode_table < first_block ||
2058 		    inode_table + sbi->s_itb_per_group - 1 > last_block) {
2059 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2060 			       "Inode table for group %u not in group "
2061 			       "(block %llu)!", i, inode_table);
2062 			return 0;
2063 		}
2064 		ext4_lock_group(sb, i);
2065 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2066 			ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2067 				 "Checksum for group %u failed (%u!=%u)",
2068 				 i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2069 				     gdp)), le16_to_cpu(gdp->bg_checksum));
2070 			if (!(sb->s_flags & MS_RDONLY)) {
2071 				ext4_unlock_group(sb, i);
2072 				return 0;
2073 			}
2074 		}
2075 		ext4_unlock_group(sb, i);
2076 		if (!flexbg_flag)
2077 			first_block += EXT4_BLOCKS_PER_GROUP(sb);
2078 	}
2079 	if (NULL != first_not_zeroed)
2080 		*first_not_zeroed = grp;
2081 
2082 	ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
2083 	sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2084 	return 1;
2085 }
2086 
2087 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2088  * the superblock) which were deleted from all directories, but held open by
2089  * a process at the time of a crash.  We walk the list and try to delete these
2090  * inodes at recovery time (only with a read-write filesystem).
2091  *
2092  * In order to keep the orphan inode chain consistent during traversal (in
2093  * case of crash during recovery), we link each inode into the superblock
2094  * orphan list_head and handle it the same way as an inode deletion during
2095  * normal operation (which journals the operations for us).
2096  *
2097  * We only do an iget() and an iput() on each inode, which is very safe if we
2098  * accidentally point at an in-use or already deleted inode.  The worst that
2099  * can happen in this case is that we get a "bit already cleared" message from
2100  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2101  * e2fsck was run on this filesystem, and it must have already done the orphan
2102  * inode cleanup for us, so we can safely abort without any further action.
2103  */
2104 static void ext4_orphan_cleanup(struct super_block *sb,
2105 				struct ext4_super_block *es)
2106 {
2107 	unsigned int s_flags = sb->s_flags;
2108 	int nr_orphans = 0, nr_truncates = 0;
2109 #ifdef CONFIG_QUOTA
2110 	int i;
2111 #endif
2112 	if (!es->s_last_orphan) {
2113 		jbd_debug(4, "no orphan inodes to clean up\n");
2114 		return;
2115 	}
2116 
2117 	if (bdev_read_only(sb->s_bdev)) {
2118 		ext4_msg(sb, KERN_ERR, "write access "
2119 			"unavailable, skipping orphan cleanup");
2120 		return;
2121 	}
2122 
2123 	if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2124 		if (es->s_last_orphan)
2125 			jbd_debug(1, "Errors on filesystem, "
2126 				  "clearing orphan list.\n");
2127 		es->s_last_orphan = 0;
2128 		jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2129 		return;
2130 	}
2131 
2132 	if (s_flags & MS_RDONLY) {
2133 		ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2134 		sb->s_flags &= ~MS_RDONLY;
2135 	}
2136 #ifdef CONFIG_QUOTA
2137 	/* Needed for iput() to work correctly and not trash data */
2138 	sb->s_flags |= MS_ACTIVE;
2139 	/* Turn on quotas so that they are updated correctly */
2140 	for (i = 0; i < MAXQUOTAS; i++) {
2141 		if (EXT4_SB(sb)->s_qf_names[i]) {
2142 			int ret = ext4_quota_on_mount(sb, i);
2143 			if (ret < 0)
2144 				ext4_msg(sb, KERN_ERR,
2145 					"Cannot turn on journaled "
2146 					"quota: error %d", ret);
2147 		}
2148 	}
2149 #endif
2150 
2151 	while (es->s_last_orphan) {
2152 		struct inode *inode;
2153 
2154 		inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2155 		if (IS_ERR(inode)) {
2156 			es->s_last_orphan = 0;
2157 			break;
2158 		}
2159 
2160 		list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2161 		dquot_initialize(inode);
2162 		if (inode->i_nlink) {
2163 			ext4_msg(sb, KERN_DEBUG,
2164 				"%s: truncating inode %lu to %lld bytes",
2165 				__func__, inode->i_ino, inode->i_size);
2166 			jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2167 				  inode->i_ino, inode->i_size);
2168 			ext4_truncate(inode);
2169 			nr_truncates++;
2170 		} else {
2171 			ext4_msg(sb, KERN_DEBUG,
2172 				"%s: deleting unreferenced inode %lu",
2173 				__func__, inode->i_ino);
2174 			jbd_debug(2, "deleting unreferenced inode %lu\n",
2175 				  inode->i_ino);
2176 			nr_orphans++;
2177 		}
2178 		iput(inode);  /* The delete magic happens here! */
2179 	}
2180 
2181 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2182 
2183 	if (nr_orphans)
2184 		ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2185 		       PLURAL(nr_orphans));
2186 	if (nr_truncates)
2187 		ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2188 		       PLURAL(nr_truncates));
2189 #ifdef CONFIG_QUOTA
2190 	/* Turn quotas off */
2191 	for (i = 0; i < MAXQUOTAS; i++) {
2192 		if (sb_dqopt(sb)->files[i])
2193 			dquot_quota_off(sb, i);
2194 	}
2195 #endif
2196 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2197 }
2198 
2199 /*
2200  * Maximal extent format file size.
2201  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2202  * extent format containers, within a sector_t, and within i_blocks
2203  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2204  * so that won't be a limiting factor.
2205  *
2206  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2207  */
2208 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2209 {
2210 	loff_t res;
2211 	loff_t upper_limit = MAX_LFS_FILESIZE;
2212 
2213 	/* small i_blocks in vfs inode? */
2214 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2215 		/*
2216 		 * CONFIG_LBDAF is not enabled implies the inode
2217 		 * i_block represent total blocks in 512 bytes
2218 		 * 32 == size of vfs inode i_blocks * 8
2219 		 */
2220 		upper_limit = (1LL << 32) - 1;
2221 
2222 		/* total blocks in file system block size */
2223 		upper_limit >>= (blkbits - 9);
2224 		upper_limit <<= blkbits;
2225 	}
2226 
2227 	/* 32-bit extent-start container, ee_block */
2228 	res = 1LL << 32;
2229 	res <<= blkbits;
2230 	res -= 1;
2231 
2232 	/* Sanity check against vm- & vfs- imposed limits */
2233 	if (res > upper_limit)
2234 		res = upper_limit;
2235 
2236 	return res;
2237 }
2238 
2239 /*
2240  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2241  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2242  * We need to be 1 filesystem block less than the 2^48 sector limit.
2243  */
2244 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2245 {
2246 	loff_t res = EXT4_NDIR_BLOCKS;
2247 	int meta_blocks;
2248 	loff_t upper_limit;
2249 	/* This is calculated to be the largest file size for a dense, block
2250 	 * mapped file such that the file's total number of 512-byte sectors,
2251 	 * including data and all indirect blocks, does not exceed (2^48 - 1).
2252 	 *
2253 	 * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2254 	 * number of 512-byte sectors of the file.
2255 	 */
2256 
2257 	if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2258 		/*
2259 		 * !has_huge_files or CONFIG_LBDAF not enabled implies that
2260 		 * the inode i_block field represents total file blocks in
2261 		 * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2262 		 */
2263 		upper_limit = (1LL << 32) - 1;
2264 
2265 		/* total blocks in file system block size */
2266 		upper_limit >>= (bits - 9);
2267 
2268 	} else {
2269 		/*
2270 		 * We use 48 bit ext4_inode i_blocks
2271 		 * With EXT4_HUGE_FILE_FL set the i_blocks
2272 		 * represent total number of blocks in
2273 		 * file system block size
2274 		 */
2275 		upper_limit = (1LL << 48) - 1;
2276 
2277 	}
2278 
2279 	/* indirect blocks */
2280 	meta_blocks = 1;
2281 	/* double indirect blocks */
2282 	meta_blocks += 1 + (1LL << (bits-2));
2283 	/* tripple indirect blocks */
2284 	meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2285 
2286 	upper_limit -= meta_blocks;
2287 	upper_limit <<= bits;
2288 
2289 	res += 1LL << (bits-2);
2290 	res += 1LL << (2*(bits-2));
2291 	res += 1LL << (3*(bits-2));
2292 	res <<= bits;
2293 	if (res > upper_limit)
2294 		res = upper_limit;
2295 
2296 	if (res > MAX_LFS_FILESIZE)
2297 		res = MAX_LFS_FILESIZE;
2298 
2299 	return res;
2300 }
2301 
2302 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2303 				   ext4_fsblk_t logical_sb_block, int nr)
2304 {
2305 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2306 	ext4_group_t bg, first_meta_bg;
2307 	int has_super = 0;
2308 
2309 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2310 
2311 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2312 	    nr < first_meta_bg)
2313 		return logical_sb_block + nr + 1;
2314 	bg = sbi->s_desc_per_block * nr;
2315 	if (ext4_bg_has_super(sb, bg))
2316 		has_super = 1;
2317 
2318 	return (has_super + ext4_group_first_block_no(sb, bg));
2319 }
2320 
2321 /**
2322  * ext4_get_stripe_size: Get the stripe size.
2323  * @sbi: In memory super block info
2324  *
2325  * If we have specified it via mount option, then
2326  * use the mount option value. If the value specified at mount time is
2327  * greater than the blocks per group use the super block value.
2328  * If the super block value is greater than blocks per group return 0.
2329  * Allocator needs it be less than blocks per group.
2330  *
2331  */
2332 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2333 {
2334 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2335 	unsigned long stripe_width =
2336 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2337 
2338 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2339 		return sbi->s_stripe;
2340 
2341 	if (stripe_width <= sbi->s_blocks_per_group)
2342 		return stripe_width;
2343 
2344 	if (stride <= sbi->s_blocks_per_group)
2345 		return stride;
2346 
2347 	return 0;
2348 }
2349 
2350 /* sysfs supprt */
2351 
2352 struct ext4_attr {
2353 	struct attribute attr;
2354 	ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2355 	ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2356 			 const char *, size_t);
2357 	int offset;
2358 };
2359 
2360 static int parse_strtoul(const char *buf,
2361 		unsigned long max, unsigned long *value)
2362 {
2363 	char *endp;
2364 
2365 	*value = simple_strtoul(skip_spaces(buf), &endp, 0);
2366 	endp = skip_spaces(endp);
2367 	if (*endp || *value > max)
2368 		return -EINVAL;
2369 
2370 	return 0;
2371 }
2372 
2373 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2374 					      struct ext4_sb_info *sbi,
2375 					      char *buf)
2376 {
2377 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2378 			(s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2379 }
2380 
2381 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2382 					 struct ext4_sb_info *sbi, char *buf)
2383 {
2384 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2385 
2386 	if (!sb->s_bdev->bd_part)
2387 		return snprintf(buf, PAGE_SIZE, "0\n");
2388 	return snprintf(buf, PAGE_SIZE, "%lu\n",
2389 			(part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2390 			 sbi->s_sectors_written_start) >> 1);
2391 }
2392 
2393 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2394 					  struct ext4_sb_info *sbi, char *buf)
2395 {
2396 	struct super_block *sb = sbi->s_buddy_cache->i_sb;
2397 
2398 	if (!sb->s_bdev->bd_part)
2399 		return snprintf(buf, PAGE_SIZE, "0\n");
2400 	return snprintf(buf, PAGE_SIZE, "%llu\n",
2401 			(unsigned long long)(sbi->s_kbytes_written +
2402 			((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2403 			  EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2404 }
2405 
2406 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2407 					  struct ext4_sb_info *sbi,
2408 					  const char *buf, size_t count)
2409 {
2410 	unsigned long t;
2411 
2412 	if (parse_strtoul(buf, 0x40000000, &t))
2413 		return -EINVAL;
2414 
2415 	if (!is_power_of_2(t))
2416 		return -EINVAL;
2417 
2418 	sbi->s_inode_readahead_blks = t;
2419 	return count;
2420 }
2421 
2422 static ssize_t sbi_ui_show(struct ext4_attr *a,
2423 			   struct ext4_sb_info *sbi, char *buf)
2424 {
2425 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2426 
2427 	return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2428 }
2429 
2430 static ssize_t sbi_ui_store(struct ext4_attr *a,
2431 			    struct ext4_sb_info *sbi,
2432 			    const char *buf, size_t count)
2433 {
2434 	unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2435 	unsigned long t;
2436 
2437 	if (parse_strtoul(buf, 0xffffffff, &t))
2438 		return -EINVAL;
2439 	*ui = t;
2440 	return count;
2441 }
2442 
2443 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2444 static struct ext4_attr ext4_attr_##_name = {			\
2445 	.attr = {.name = __stringify(_name), .mode = _mode },	\
2446 	.show	= _show,					\
2447 	.store	= _store,					\
2448 	.offset = offsetof(struct ext4_sb_info, _elname),	\
2449 }
2450 #define EXT4_ATTR(name, mode, show, store) \
2451 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2452 
2453 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2454 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2455 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2456 #define EXT4_RW_ATTR_SBI_UI(name, elname)	\
2457 	EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2458 #define ATTR_LIST(name) &ext4_attr_##name.attr
2459 
2460 EXT4_RO_ATTR(delayed_allocation_blocks);
2461 EXT4_RO_ATTR(session_write_kbytes);
2462 EXT4_RO_ATTR(lifetime_write_kbytes);
2463 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2464 		 inode_readahead_blks_store, s_inode_readahead_blks);
2465 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2466 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2467 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2468 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2469 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2470 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2471 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2472 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2473 
2474 static struct attribute *ext4_attrs[] = {
2475 	ATTR_LIST(delayed_allocation_blocks),
2476 	ATTR_LIST(session_write_kbytes),
2477 	ATTR_LIST(lifetime_write_kbytes),
2478 	ATTR_LIST(inode_readahead_blks),
2479 	ATTR_LIST(inode_goal),
2480 	ATTR_LIST(mb_stats),
2481 	ATTR_LIST(mb_max_to_scan),
2482 	ATTR_LIST(mb_min_to_scan),
2483 	ATTR_LIST(mb_order2_req),
2484 	ATTR_LIST(mb_stream_req),
2485 	ATTR_LIST(mb_group_prealloc),
2486 	ATTR_LIST(max_writeback_mb_bump),
2487 	NULL,
2488 };
2489 
2490 /* Features this copy of ext4 supports */
2491 EXT4_INFO_ATTR(lazy_itable_init);
2492 EXT4_INFO_ATTR(batched_discard);
2493 
2494 static struct attribute *ext4_feat_attrs[] = {
2495 	ATTR_LIST(lazy_itable_init),
2496 	ATTR_LIST(batched_discard),
2497 	NULL,
2498 };
2499 
2500 static ssize_t ext4_attr_show(struct kobject *kobj,
2501 			      struct attribute *attr, char *buf)
2502 {
2503 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2504 						s_kobj);
2505 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2506 
2507 	return a->show ? a->show(a, sbi, buf) : 0;
2508 }
2509 
2510 static ssize_t ext4_attr_store(struct kobject *kobj,
2511 			       struct attribute *attr,
2512 			       const char *buf, size_t len)
2513 {
2514 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2515 						s_kobj);
2516 	struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2517 
2518 	return a->store ? a->store(a, sbi, buf, len) : 0;
2519 }
2520 
2521 static void ext4_sb_release(struct kobject *kobj)
2522 {
2523 	struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2524 						s_kobj);
2525 	complete(&sbi->s_kobj_unregister);
2526 }
2527 
2528 static const struct sysfs_ops ext4_attr_ops = {
2529 	.show	= ext4_attr_show,
2530 	.store	= ext4_attr_store,
2531 };
2532 
2533 static struct kobj_type ext4_ktype = {
2534 	.default_attrs	= ext4_attrs,
2535 	.sysfs_ops	= &ext4_attr_ops,
2536 	.release	= ext4_sb_release,
2537 };
2538 
2539 static void ext4_feat_release(struct kobject *kobj)
2540 {
2541 	complete(&ext4_feat->f_kobj_unregister);
2542 }
2543 
2544 static struct kobj_type ext4_feat_ktype = {
2545 	.default_attrs	= ext4_feat_attrs,
2546 	.sysfs_ops	= &ext4_attr_ops,
2547 	.release	= ext4_feat_release,
2548 };
2549 
2550 /*
2551  * Check whether this filesystem can be mounted based on
2552  * the features present and the RDONLY/RDWR mount requested.
2553  * Returns 1 if this filesystem can be mounted as requested,
2554  * 0 if it cannot be.
2555  */
2556 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2557 {
2558 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2559 		ext4_msg(sb, KERN_ERR,
2560 			"Couldn't mount because of "
2561 			"unsupported optional features (%x)",
2562 			(le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2563 			~EXT4_FEATURE_INCOMPAT_SUPP));
2564 		return 0;
2565 	}
2566 
2567 	if (readonly)
2568 		return 1;
2569 
2570 	/* Check that feature set is OK for a read-write mount */
2571 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2572 		ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2573 			 "unsupported optional features (%x)",
2574 			 (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2575 				~EXT4_FEATURE_RO_COMPAT_SUPP));
2576 		return 0;
2577 	}
2578 	/*
2579 	 * Large file size enabled file system can only be mounted
2580 	 * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2581 	 */
2582 	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2583 		if (sizeof(blkcnt_t) < sizeof(u64)) {
2584 			ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2585 				 "cannot be mounted RDWR without "
2586 				 "CONFIG_LBDAF");
2587 			return 0;
2588 		}
2589 	}
2590 	return 1;
2591 }
2592 
2593 /*
2594  * This function is called once a day if we have errors logged
2595  * on the file system
2596  */
2597 static void print_daily_error_info(unsigned long arg)
2598 {
2599 	struct super_block *sb = (struct super_block *) arg;
2600 	struct ext4_sb_info *sbi;
2601 	struct ext4_super_block *es;
2602 
2603 	sbi = EXT4_SB(sb);
2604 	es = sbi->s_es;
2605 
2606 	if (es->s_error_count)
2607 		ext4_msg(sb, KERN_NOTICE, "error count: %u",
2608 			 le32_to_cpu(es->s_error_count));
2609 	if (es->s_first_error_time) {
2610 		printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2611 		       sb->s_id, le32_to_cpu(es->s_first_error_time),
2612 		       (int) sizeof(es->s_first_error_func),
2613 		       es->s_first_error_func,
2614 		       le32_to_cpu(es->s_first_error_line));
2615 		if (es->s_first_error_ino)
2616 			printk(": inode %u",
2617 			       le32_to_cpu(es->s_first_error_ino));
2618 		if (es->s_first_error_block)
2619 			printk(": block %llu", (unsigned long long)
2620 			       le64_to_cpu(es->s_first_error_block));
2621 		printk("\n");
2622 	}
2623 	if (es->s_last_error_time) {
2624 		printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2625 		       sb->s_id, le32_to_cpu(es->s_last_error_time),
2626 		       (int) sizeof(es->s_last_error_func),
2627 		       es->s_last_error_func,
2628 		       le32_to_cpu(es->s_last_error_line));
2629 		if (es->s_last_error_ino)
2630 			printk(": inode %u",
2631 			       le32_to_cpu(es->s_last_error_ino));
2632 		if (es->s_last_error_block)
2633 			printk(": block %llu", (unsigned long long)
2634 			       le64_to_cpu(es->s_last_error_block));
2635 		printk("\n");
2636 	}
2637 	mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2638 }
2639 
2640 static void ext4_lazyinode_timeout(unsigned long data)
2641 {
2642 	struct task_struct *p = (struct task_struct *)data;
2643 	wake_up_process(p);
2644 }
2645 
2646 /* Find next suitable group and run ext4_init_inode_table */
2647 static int ext4_run_li_request(struct ext4_li_request *elr)
2648 {
2649 	struct ext4_group_desc *gdp = NULL;
2650 	ext4_group_t group, ngroups;
2651 	struct super_block *sb;
2652 	unsigned long timeout = 0;
2653 	int ret = 0;
2654 
2655 	sb = elr->lr_super;
2656 	ngroups = EXT4_SB(sb)->s_groups_count;
2657 
2658 	for (group = elr->lr_next_group; group < ngroups; group++) {
2659 		gdp = ext4_get_group_desc(sb, group, NULL);
2660 		if (!gdp) {
2661 			ret = 1;
2662 			break;
2663 		}
2664 
2665 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2666 			break;
2667 	}
2668 
2669 	if (group == ngroups)
2670 		ret = 1;
2671 
2672 	if (!ret) {
2673 		timeout = jiffies;
2674 		ret = ext4_init_inode_table(sb, group,
2675 					    elr->lr_timeout ? 0 : 1);
2676 		if (elr->lr_timeout == 0) {
2677 			timeout = jiffies - timeout;
2678 			if (elr->lr_sbi->s_li_wait_mult)
2679 				timeout *= elr->lr_sbi->s_li_wait_mult;
2680 			else
2681 				timeout *= 20;
2682 			elr->lr_timeout = timeout;
2683 		}
2684 		elr->lr_next_sched = jiffies + elr->lr_timeout;
2685 		elr->lr_next_group = group + 1;
2686 	}
2687 
2688 	return ret;
2689 }
2690 
2691 /*
2692  * Remove lr_request from the list_request and free the
2693  * request tructure. Should be called with li_list_mtx held
2694  */
2695 static void ext4_remove_li_request(struct ext4_li_request *elr)
2696 {
2697 	struct ext4_sb_info *sbi;
2698 
2699 	if (!elr)
2700 		return;
2701 
2702 	sbi = elr->lr_sbi;
2703 
2704 	list_del(&elr->lr_request);
2705 	sbi->s_li_request = NULL;
2706 	kfree(elr);
2707 }
2708 
2709 static void ext4_unregister_li_request(struct super_block *sb)
2710 {
2711 	struct ext4_li_request *elr = EXT4_SB(sb)->s_li_request;
2712 
2713 	if (!ext4_li_info)
2714 		return;
2715 
2716 	mutex_lock(&ext4_li_info->li_list_mtx);
2717 	ext4_remove_li_request(elr);
2718 	mutex_unlock(&ext4_li_info->li_list_mtx);
2719 }
2720 
2721 static struct task_struct *ext4_lazyinit_task;
2722 
2723 /*
2724  * This is the function where ext4lazyinit thread lives. It walks
2725  * through the request list searching for next scheduled filesystem.
2726  * When such a fs is found, run the lazy initialization request
2727  * (ext4_rn_li_request) and keep track of the time spend in this
2728  * function. Based on that time we compute next schedule time of
2729  * the request. When walking through the list is complete, compute
2730  * next waking time and put itself into sleep.
2731  */
2732 static int ext4_lazyinit_thread(void *arg)
2733 {
2734 	struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2735 	struct list_head *pos, *n;
2736 	struct ext4_li_request *elr;
2737 	unsigned long next_wakeup;
2738 	DEFINE_WAIT(wait);
2739 
2740 	BUG_ON(NULL == eli);
2741 
2742 	eli->li_timer.data = (unsigned long)current;
2743 	eli->li_timer.function = ext4_lazyinode_timeout;
2744 
2745 	eli->li_task = current;
2746 	wake_up(&eli->li_wait_task);
2747 
2748 cont_thread:
2749 	while (true) {
2750 		next_wakeup = MAX_JIFFY_OFFSET;
2751 
2752 		mutex_lock(&eli->li_list_mtx);
2753 		if (list_empty(&eli->li_request_list)) {
2754 			mutex_unlock(&eli->li_list_mtx);
2755 			goto exit_thread;
2756 		}
2757 
2758 		list_for_each_safe(pos, n, &eli->li_request_list) {
2759 			elr = list_entry(pos, struct ext4_li_request,
2760 					 lr_request);
2761 
2762 			if (time_after_eq(jiffies, elr->lr_next_sched)) {
2763 				if (ext4_run_li_request(elr) != 0) {
2764 					/* error, remove the lazy_init job */
2765 					ext4_remove_li_request(elr);
2766 					continue;
2767 				}
2768 			}
2769 
2770 			if (time_before(elr->lr_next_sched, next_wakeup))
2771 				next_wakeup = elr->lr_next_sched;
2772 		}
2773 		mutex_unlock(&eli->li_list_mtx);
2774 
2775 		if (freezing(current))
2776 			refrigerator();
2777 
2778 		if ((time_after_eq(jiffies, next_wakeup)) ||
2779 		    (MAX_JIFFY_OFFSET == next_wakeup)) {
2780 			cond_resched();
2781 			continue;
2782 		}
2783 
2784 		eli->li_timer.expires = next_wakeup;
2785 		add_timer(&eli->li_timer);
2786 		prepare_to_wait(&eli->li_wait_daemon, &wait,
2787 				TASK_INTERRUPTIBLE);
2788 		if (time_before(jiffies, next_wakeup))
2789 			schedule();
2790 		finish_wait(&eli->li_wait_daemon, &wait);
2791 		if (kthread_should_stop()) {
2792 			ext4_clear_request_list();
2793 			goto exit_thread;
2794 		}
2795 	}
2796 
2797 exit_thread:
2798 	/*
2799 	 * It looks like the request list is empty, but we need
2800 	 * to check it under the li_list_mtx lock, to prevent any
2801 	 * additions into it, and of course we should lock ext4_li_mtx
2802 	 * to atomically free the list and ext4_li_info, because at
2803 	 * this point another ext4 filesystem could be registering
2804 	 * new one.
2805 	 */
2806 	mutex_lock(&ext4_li_mtx);
2807 	mutex_lock(&eli->li_list_mtx);
2808 	if (!list_empty(&eli->li_request_list)) {
2809 		mutex_unlock(&eli->li_list_mtx);
2810 		mutex_unlock(&ext4_li_mtx);
2811 		goto cont_thread;
2812 	}
2813 	mutex_unlock(&eli->li_list_mtx);
2814 	del_timer_sync(&ext4_li_info->li_timer);
2815 	eli->li_task = NULL;
2816 	wake_up(&eli->li_wait_task);
2817 
2818 	kfree(ext4_li_info);
2819 	ext4_lazyinit_task = NULL;
2820 	ext4_li_info = NULL;
2821 	mutex_unlock(&ext4_li_mtx);
2822 
2823 	return 0;
2824 }
2825 
2826 static void ext4_clear_request_list(void)
2827 {
2828 	struct list_head *pos, *n;
2829 	struct ext4_li_request *elr;
2830 
2831 	mutex_lock(&ext4_li_info->li_list_mtx);
2832 	list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2833 		elr = list_entry(pos, struct ext4_li_request,
2834 				 lr_request);
2835 		ext4_remove_li_request(elr);
2836 	}
2837 	mutex_unlock(&ext4_li_info->li_list_mtx);
2838 }
2839 
2840 static int ext4_run_lazyinit_thread(void)
2841 {
2842 	ext4_lazyinit_task = kthread_run(ext4_lazyinit_thread,
2843 					 ext4_li_info, "ext4lazyinit");
2844 	if (IS_ERR(ext4_lazyinit_task)) {
2845 		int err = PTR_ERR(ext4_lazyinit_task);
2846 		ext4_clear_request_list();
2847 		del_timer_sync(&ext4_li_info->li_timer);
2848 		kfree(ext4_li_info);
2849 		ext4_li_info = NULL;
2850 		printk(KERN_CRIT "EXT4: error %d creating inode table "
2851 				 "initialization thread\n",
2852 				 err);
2853 		return err;
2854 	}
2855 	ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2856 
2857 	wait_event(ext4_li_info->li_wait_task, ext4_li_info->li_task != NULL);
2858 	return 0;
2859 }
2860 
2861 /*
2862  * Check whether it make sense to run itable init. thread or not.
2863  * If there is at least one uninitialized inode table, return
2864  * corresponding group number, else the loop goes through all
2865  * groups and return total number of groups.
2866  */
2867 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2868 {
2869 	ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2870 	struct ext4_group_desc *gdp = NULL;
2871 
2872 	for (group = 0; group < ngroups; group++) {
2873 		gdp = ext4_get_group_desc(sb, group, NULL);
2874 		if (!gdp)
2875 			continue;
2876 
2877 		if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2878 			break;
2879 	}
2880 
2881 	return group;
2882 }
2883 
2884 static int ext4_li_info_new(void)
2885 {
2886 	struct ext4_lazy_init *eli = NULL;
2887 
2888 	eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2889 	if (!eli)
2890 		return -ENOMEM;
2891 
2892 	eli->li_task = NULL;
2893 	INIT_LIST_HEAD(&eli->li_request_list);
2894 	mutex_init(&eli->li_list_mtx);
2895 
2896 	init_waitqueue_head(&eli->li_wait_daemon);
2897 	init_waitqueue_head(&eli->li_wait_task);
2898 	init_timer(&eli->li_timer);
2899 	eli->li_state |= EXT4_LAZYINIT_QUIT;
2900 
2901 	ext4_li_info = eli;
2902 
2903 	return 0;
2904 }
2905 
2906 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2907 					    ext4_group_t start)
2908 {
2909 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2910 	struct ext4_li_request *elr;
2911 	unsigned long rnd;
2912 
2913 	elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2914 	if (!elr)
2915 		return NULL;
2916 
2917 	elr->lr_super = sb;
2918 	elr->lr_sbi = sbi;
2919 	elr->lr_next_group = start;
2920 
2921 	/*
2922 	 * Randomize first schedule time of the request to
2923 	 * spread the inode table initialization requests
2924 	 * better.
2925 	 */
2926 	get_random_bytes(&rnd, sizeof(rnd));
2927 	elr->lr_next_sched = jiffies + (unsigned long)rnd %
2928 			     (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2929 
2930 	return elr;
2931 }
2932 
2933 static int ext4_register_li_request(struct super_block *sb,
2934 				    ext4_group_t first_not_zeroed)
2935 {
2936 	struct ext4_sb_info *sbi = EXT4_SB(sb);
2937 	struct ext4_li_request *elr;
2938 	ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2939 	int ret = 0;
2940 
2941 	if (sbi->s_li_request != NULL)
2942 		return 0;
2943 
2944 	if (first_not_zeroed == ngroups ||
2945 	    (sb->s_flags & MS_RDONLY) ||
2946 	    !test_opt(sb, INIT_INODE_TABLE)) {
2947 		sbi->s_li_request = NULL;
2948 		return 0;
2949 	}
2950 
2951 	if (first_not_zeroed == ngroups) {
2952 		sbi->s_li_request = NULL;
2953 		return 0;
2954 	}
2955 
2956 	elr = ext4_li_request_new(sb, first_not_zeroed);
2957 	if (!elr)
2958 		return -ENOMEM;
2959 
2960 	mutex_lock(&ext4_li_mtx);
2961 
2962 	if (NULL == ext4_li_info) {
2963 		ret = ext4_li_info_new();
2964 		if (ret)
2965 			goto out;
2966 	}
2967 
2968 	mutex_lock(&ext4_li_info->li_list_mtx);
2969 	list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2970 	mutex_unlock(&ext4_li_info->li_list_mtx);
2971 
2972 	sbi->s_li_request = elr;
2973 
2974 	if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2975 		ret = ext4_run_lazyinit_thread();
2976 		if (ret)
2977 			goto out;
2978 	}
2979 out:
2980 	mutex_unlock(&ext4_li_mtx);
2981 	if (ret)
2982 		kfree(elr);
2983 	return ret;
2984 }
2985 
2986 /*
2987  * We do not need to lock anything since this is called on
2988  * module unload.
2989  */
2990 static void ext4_destroy_lazyinit_thread(void)
2991 {
2992 	/*
2993 	 * If thread exited earlier
2994 	 * there's nothing to be done.
2995 	 */
2996 	if (!ext4_li_info || !ext4_lazyinit_task)
2997 		return;
2998 
2999 	kthread_stop(ext4_lazyinit_task);
3000 }
3001 
3002 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
3003 				__releases(kernel_lock)
3004 				__acquires(kernel_lock)
3005 {
3006 	char *orig_data = kstrdup(data, GFP_KERNEL);
3007 	struct buffer_head *bh;
3008 	struct ext4_super_block *es = NULL;
3009 	struct ext4_sb_info *sbi;
3010 	ext4_fsblk_t block;
3011 	ext4_fsblk_t sb_block = get_sb_block(&data);
3012 	ext4_fsblk_t logical_sb_block;
3013 	unsigned long offset = 0;
3014 	unsigned long journal_devnum = 0;
3015 	unsigned long def_mount_opts;
3016 	struct inode *root;
3017 	char *cp;
3018 	const char *descr;
3019 	int ret = -ENOMEM;
3020 	int blocksize;
3021 	unsigned int db_count;
3022 	unsigned int i;
3023 	int needs_recovery, has_huge_files;
3024 	__u64 blocks_count;
3025 	int err;
3026 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3027 	ext4_group_t first_not_zeroed;
3028 
3029 	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3030 	if (!sbi)
3031 		goto out_free_orig;
3032 
3033 	sbi->s_blockgroup_lock =
3034 		kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3035 	if (!sbi->s_blockgroup_lock) {
3036 		kfree(sbi);
3037 		goto out_free_orig;
3038 	}
3039 	sb->s_fs_info = sbi;
3040 	sbi->s_mount_opt = 0;
3041 	sbi->s_resuid = EXT4_DEF_RESUID;
3042 	sbi->s_resgid = EXT4_DEF_RESGID;
3043 	sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3044 	sbi->s_sb_block = sb_block;
3045 	if (sb->s_bdev->bd_part)
3046 		sbi->s_sectors_written_start =
3047 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3048 
3049 	/* Cleanup superblock name */
3050 	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3051 		*cp = '!';
3052 
3053 	ret = -EINVAL;
3054 	blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3055 	if (!blocksize) {
3056 		ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3057 		goto out_fail;
3058 	}
3059 
3060 	/*
3061 	 * The ext4 superblock will not be buffer aligned for other than 1kB
3062 	 * block sizes.  We need to calculate the offset from buffer start.
3063 	 */
3064 	if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3065 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3066 		offset = do_div(logical_sb_block, blocksize);
3067 	} else {
3068 		logical_sb_block = sb_block;
3069 	}
3070 
3071 	if (!(bh = sb_bread(sb, logical_sb_block))) {
3072 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
3073 		goto out_fail;
3074 	}
3075 	/*
3076 	 * Note: s_es must be initialized as soon as possible because
3077 	 *       some ext4 macro-instructions depend on its value
3078 	 */
3079 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3080 	sbi->s_es = es;
3081 	sb->s_magic = le16_to_cpu(es->s_magic);
3082 	if (sb->s_magic != EXT4_SUPER_MAGIC)
3083 		goto cantfind_ext4;
3084 	sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3085 
3086 	/* Set defaults before we parse the mount options */
3087 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3088 	set_opt(sb, INIT_INODE_TABLE);
3089 	if (def_mount_opts & EXT4_DEFM_DEBUG)
3090 		set_opt(sb, DEBUG);
3091 	if (def_mount_opts & EXT4_DEFM_BSDGROUPS) {
3092 		ext4_msg(sb, KERN_WARNING, deprecated_msg, "bsdgroups",
3093 			"2.6.38");
3094 		set_opt(sb, GRPID);
3095 	}
3096 	if (def_mount_opts & EXT4_DEFM_UID16)
3097 		set_opt(sb, NO_UID32);
3098 #ifdef CONFIG_EXT4_FS_XATTR
3099 	if (def_mount_opts & EXT4_DEFM_XATTR_USER)
3100 		set_opt(sb, XATTR_USER);
3101 #endif
3102 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3103 	if (def_mount_opts & EXT4_DEFM_ACL)
3104 		set_opt(sb, POSIX_ACL);
3105 #endif
3106 	if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3107 		set_opt(sb, JOURNAL_DATA);
3108 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3109 		set_opt(sb, ORDERED_DATA);
3110 	else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3111 		set_opt(sb, WRITEBACK_DATA);
3112 
3113 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3114 		set_opt(sb, ERRORS_PANIC);
3115 	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3116 		set_opt(sb, ERRORS_CONT);
3117 	else
3118 		set_opt(sb, ERRORS_RO);
3119 	if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3120 		set_opt(sb, BLOCK_VALIDITY);
3121 	if (def_mount_opts & EXT4_DEFM_DISCARD)
3122 		set_opt(sb, DISCARD);
3123 
3124 	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
3125 	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
3126 	sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3127 	sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3128 	sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3129 
3130 	if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3131 		set_opt(sb, BARRIER);
3132 
3133 	/*
3134 	 * enable delayed allocation by default
3135 	 * Use -o nodelalloc to turn it off
3136 	 */
3137 	if (!IS_EXT3_SB(sb) &&
3138 	    ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3139 		set_opt(sb, DELALLOC);
3140 
3141 	if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3142 			   &journal_devnum, &journal_ioprio, NULL, 0)) {
3143 		ext4_msg(sb, KERN_WARNING,
3144 			 "failed to parse options in superblock: %s",
3145 			 sbi->s_es->s_mount_opts);
3146 	}
3147 	if (!parse_options((char *) data, sb, &journal_devnum,
3148 			   &journal_ioprio, NULL, 0))
3149 		goto failed_mount;
3150 
3151 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3152 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3153 
3154 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3155 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3156 	     EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3157 	     EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3158 		ext4_msg(sb, KERN_WARNING,
3159 		       "feature flags set on rev 0 fs, "
3160 		       "running e2fsck is recommended");
3161 
3162 	/*
3163 	 * Check feature flags regardless of the revision level, since we
3164 	 * previously didn't change the revision level when setting the flags,
3165 	 * so there is a chance incompat flags are set on a rev 0 filesystem.
3166 	 */
3167 	if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3168 		goto failed_mount;
3169 
3170 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3171 
3172 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3173 	    blocksize > EXT4_MAX_BLOCK_SIZE) {
3174 		ext4_msg(sb, KERN_ERR,
3175 		       "Unsupported filesystem blocksize %d", blocksize);
3176 		goto failed_mount;
3177 	}
3178 
3179 	if (sb->s_blocksize != blocksize) {
3180 		/* Validate the filesystem blocksize */
3181 		if (!sb_set_blocksize(sb, blocksize)) {
3182 			ext4_msg(sb, KERN_ERR, "bad block size %d",
3183 					blocksize);
3184 			goto failed_mount;
3185 		}
3186 
3187 		brelse(bh);
3188 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3189 		offset = do_div(logical_sb_block, blocksize);
3190 		bh = sb_bread(sb, logical_sb_block);
3191 		if (!bh) {
3192 			ext4_msg(sb, KERN_ERR,
3193 			       "Can't read superblock on 2nd try");
3194 			goto failed_mount;
3195 		}
3196 		es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
3197 		sbi->s_es = es;
3198 		if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3199 			ext4_msg(sb, KERN_ERR,
3200 			       "Magic mismatch, very weird!");
3201 			goto failed_mount;
3202 		}
3203 	}
3204 
3205 	has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3206 				EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3207 	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3208 						      has_huge_files);
3209 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3210 
3211 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3212 		sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3213 		sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3214 	} else {
3215 		sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3216 		sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3217 		if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3218 		    (!is_power_of_2(sbi->s_inode_size)) ||
3219 		    (sbi->s_inode_size > blocksize)) {
3220 			ext4_msg(sb, KERN_ERR,
3221 			       "unsupported inode size: %d",
3222 			       sbi->s_inode_size);
3223 			goto failed_mount;
3224 		}
3225 		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3226 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3227 	}
3228 
3229 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3230 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3231 		if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3232 		    sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3233 		    !is_power_of_2(sbi->s_desc_size)) {
3234 			ext4_msg(sb, KERN_ERR,
3235 			       "unsupported descriptor size %lu",
3236 			       sbi->s_desc_size);
3237 			goto failed_mount;
3238 		}
3239 	} else
3240 		sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3241 
3242 	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3243 	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3244 	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3245 		goto cantfind_ext4;
3246 
3247 	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3248 	if (sbi->s_inodes_per_block == 0)
3249 		goto cantfind_ext4;
3250 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
3251 					sbi->s_inodes_per_block;
3252 	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3253 	sbi->s_sbh = bh;
3254 	sbi->s_mount_state = le16_to_cpu(es->s_state);
3255 	sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3256 	sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3257 
3258 	for (i = 0; i < 4; i++)
3259 		sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3260 	sbi->s_def_hash_version = es->s_def_hash_version;
3261 	i = le32_to_cpu(es->s_flags);
3262 	if (i & EXT2_FLAGS_UNSIGNED_HASH)
3263 		sbi->s_hash_unsigned = 3;
3264 	else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3265 #ifdef __CHAR_UNSIGNED__
3266 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3267 		sbi->s_hash_unsigned = 3;
3268 #else
3269 		es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3270 #endif
3271 		sb->s_dirt = 1;
3272 	}
3273 
3274 	if (sbi->s_blocks_per_group > blocksize * 8) {
3275 		ext4_msg(sb, KERN_ERR,
3276 		       "#blocks per group too big: %lu",
3277 		       sbi->s_blocks_per_group);
3278 		goto failed_mount;
3279 	}
3280 	if (sbi->s_inodes_per_group > blocksize * 8) {
3281 		ext4_msg(sb, KERN_ERR,
3282 		       "#inodes per group too big: %lu",
3283 		       sbi->s_inodes_per_group);
3284 		goto failed_mount;
3285 	}
3286 
3287 	/*
3288 	 * Test whether we have more sectors than will fit in sector_t,
3289 	 * and whether the max offset is addressable by the page cache.
3290 	 */
3291 	err = generic_check_addressable(sb->s_blocksize_bits,
3292 					ext4_blocks_count(es));
3293 	if (err) {
3294 		ext4_msg(sb, KERN_ERR, "filesystem"
3295 			 " too large to mount safely on this system");
3296 		if (sizeof(sector_t) < 8)
3297 			ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3298 		ret = err;
3299 		goto failed_mount;
3300 	}
3301 
3302 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3303 		goto cantfind_ext4;
3304 
3305 	/* check blocks count against device size */
3306 	blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3307 	if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3308 		ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3309 		       "exceeds size of device (%llu blocks)",
3310 		       ext4_blocks_count(es), blocks_count);
3311 		goto failed_mount;
3312 	}
3313 
3314 	/*
3315 	 * It makes no sense for the first data block to be beyond the end
3316 	 * of the filesystem.
3317 	 */
3318 	if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3319                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
3320 			 "block %u is beyond end of filesystem (%llu)",
3321 			 le32_to_cpu(es->s_first_data_block),
3322 			 ext4_blocks_count(es));
3323 		goto failed_mount;
3324 	}
3325 	blocks_count = (ext4_blocks_count(es) -
3326 			le32_to_cpu(es->s_first_data_block) +
3327 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
3328 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3329 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3330 		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3331 		       "(block count %llu, first data block %u, "
3332 		       "blocks per group %lu)", sbi->s_groups_count,
3333 		       ext4_blocks_count(es),
3334 		       le32_to_cpu(es->s_first_data_block),
3335 		       EXT4_BLOCKS_PER_GROUP(sb));
3336 		goto failed_mount;
3337 	}
3338 	sbi->s_groups_count = blocks_count;
3339 	sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3340 			(EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3341 	db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3342 		   EXT4_DESC_PER_BLOCK(sb);
3343 	sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
3344 				    GFP_KERNEL);
3345 	if (sbi->s_group_desc == NULL) {
3346 		ext4_msg(sb, KERN_ERR, "not enough memory");
3347 		goto failed_mount;
3348 	}
3349 
3350 #ifdef CONFIG_PROC_FS
3351 	if (ext4_proc_root)
3352 		sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3353 #endif
3354 
3355 	bgl_lock_init(sbi->s_blockgroup_lock);
3356 
3357 	for (i = 0; i < db_count; i++) {
3358 		block = descriptor_loc(sb, logical_sb_block, i);
3359 		sbi->s_group_desc[i] = sb_bread(sb, block);
3360 		if (!sbi->s_group_desc[i]) {
3361 			ext4_msg(sb, KERN_ERR,
3362 			       "can't read group descriptor %d", i);
3363 			db_count = i;
3364 			goto failed_mount2;
3365 		}
3366 	}
3367 	if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3368 		ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3369 		goto failed_mount2;
3370 	}
3371 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3372 		if (!ext4_fill_flex_info(sb)) {
3373 			ext4_msg(sb, KERN_ERR,
3374 			       "unable to initialize "
3375 			       "flex_bg meta info!");
3376 			goto failed_mount2;
3377 		}
3378 
3379 	sbi->s_gdb_count = db_count;
3380 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3381 	spin_lock_init(&sbi->s_next_gen_lock);
3382 
3383 	err = percpu_counter_init(&sbi->s_freeblocks_counter,
3384 			ext4_count_free_blocks(sb));
3385 	if (!err) {
3386 		err = percpu_counter_init(&sbi->s_freeinodes_counter,
3387 				ext4_count_free_inodes(sb));
3388 	}
3389 	if (!err) {
3390 		err = percpu_counter_init(&sbi->s_dirs_counter,
3391 				ext4_count_dirs(sb));
3392 	}
3393 	if (!err) {
3394 		err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
3395 	}
3396 	if (err) {
3397 		ext4_msg(sb, KERN_ERR, "insufficient memory");
3398 		goto failed_mount3;
3399 	}
3400 
3401 	sbi->s_stripe = ext4_get_stripe_size(sbi);
3402 	sbi->s_max_writeback_mb_bump = 128;
3403 
3404 	/*
3405 	 * set up enough so that it can read an inode
3406 	 */
3407 	if (!test_opt(sb, NOLOAD) &&
3408 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3409 		sb->s_op = &ext4_sops;
3410 	else
3411 		sb->s_op = &ext4_nojournal_sops;
3412 	sb->s_export_op = &ext4_export_ops;
3413 	sb->s_xattr = ext4_xattr_handlers;
3414 #ifdef CONFIG_QUOTA
3415 	sb->s_qcop = &ext4_qctl_operations;
3416 	sb->dq_op = &ext4_quota_operations;
3417 #endif
3418 	INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3419 	mutex_init(&sbi->s_orphan_lock);
3420 	mutex_init(&sbi->s_resize_lock);
3421 
3422 	sb->s_root = NULL;
3423 
3424 	needs_recovery = (es->s_last_orphan != 0 ||
3425 			  EXT4_HAS_INCOMPAT_FEATURE(sb,
3426 				    EXT4_FEATURE_INCOMPAT_RECOVER));
3427 
3428 	/*
3429 	 * The first inode we look at is the journal inode.  Don't try
3430 	 * root first: it may be modified in the journal!
3431 	 */
3432 	if (!test_opt(sb, NOLOAD) &&
3433 	    EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3434 		if (ext4_load_journal(sb, es, journal_devnum))
3435 			goto failed_mount3;
3436 	} else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3437 	      EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3438 		ext4_msg(sb, KERN_ERR, "required journal recovery "
3439 		       "suppressed and not mounted read-only");
3440 		goto failed_mount_wq;
3441 	} else {
3442 		clear_opt(sb, DATA_FLAGS);
3443 		set_opt(sb, WRITEBACK_DATA);
3444 		sbi->s_journal = NULL;
3445 		needs_recovery = 0;
3446 		goto no_journal;
3447 	}
3448 
3449 	if (ext4_blocks_count(es) > 0xffffffffULL &&
3450 	    !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3451 				       JBD2_FEATURE_INCOMPAT_64BIT)) {
3452 		ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3453 		goto failed_mount_wq;
3454 	}
3455 
3456 	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3457 		jbd2_journal_set_features(sbi->s_journal,
3458 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3459 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3460 	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3461 		jbd2_journal_set_features(sbi->s_journal,
3462 				JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
3463 		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3464 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3465 	} else {
3466 		jbd2_journal_clear_features(sbi->s_journal,
3467 				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3468 				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3469 	}
3470 
3471 	/* We have now updated the journal if required, so we can
3472 	 * validate the data journaling mode. */
3473 	switch (test_opt(sb, DATA_FLAGS)) {
3474 	case 0:
3475 		/* No mode set, assume a default based on the journal
3476 		 * capabilities: ORDERED_DATA if the journal can
3477 		 * cope, else JOURNAL_DATA
3478 		 */
3479 		if (jbd2_journal_check_available_features
3480 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3481 			set_opt(sb, ORDERED_DATA);
3482 		else
3483 			set_opt(sb, JOURNAL_DATA);
3484 		break;
3485 
3486 	case EXT4_MOUNT_ORDERED_DATA:
3487 	case EXT4_MOUNT_WRITEBACK_DATA:
3488 		if (!jbd2_journal_check_available_features
3489 		    (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3490 			ext4_msg(sb, KERN_ERR, "Journal does not support "
3491 			       "requested data journaling mode");
3492 			goto failed_mount_wq;
3493 		}
3494 	default:
3495 		break;
3496 	}
3497 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3498 
3499 	/*
3500 	 * The journal may have updated the bg summary counts, so we
3501 	 * need to update the global counters.
3502 	 */
3503 	percpu_counter_set(&sbi->s_freeblocks_counter,
3504 			   ext4_count_free_blocks(sb));
3505 	percpu_counter_set(&sbi->s_freeinodes_counter,
3506 			   ext4_count_free_inodes(sb));
3507 	percpu_counter_set(&sbi->s_dirs_counter,
3508 			   ext4_count_dirs(sb));
3509 	percpu_counter_set(&sbi->s_dirtyblocks_counter, 0);
3510 
3511 no_journal:
3512 	EXT4_SB(sb)->dio_unwritten_wq = create_workqueue("ext4-dio-unwritten");
3513 	if (!EXT4_SB(sb)->dio_unwritten_wq) {
3514 		printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3515 		goto failed_mount_wq;
3516 	}
3517 
3518 	/*
3519 	 * The jbd2_journal_load will have done any necessary log recovery,
3520 	 * so we can safely mount the rest of the filesystem now.
3521 	 */
3522 
3523 	root = ext4_iget(sb, EXT4_ROOT_INO);
3524 	if (IS_ERR(root)) {
3525 		ext4_msg(sb, KERN_ERR, "get root inode failed");
3526 		ret = PTR_ERR(root);
3527 		goto failed_mount4;
3528 	}
3529 	if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3530 		iput(root);
3531 		ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3532 		goto failed_mount4;
3533 	}
3534 	sb->s_root = d_alloc_root(root);
3535 	if (!sb->s_root) {
3536 		ext4_msg(sb, KERN_ERR, "get root dentry failed");
3537 		iput(root);
3538 		ret = -ENOMEM;
3539 		goto failed_mount4;
3540 	}
3541 
3542 	ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
3543 
3544 	/* determine the minimum size of new large inodes, if present */
3545 	if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3546 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3547 						     EXT4_GOOD_OLD_INODE_SIZE;
3548 		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3549 				       EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3550 			if (sbi->s_want_extra_isize <
3551 			    le16_to_cpu(es->s_want_extra_isize))
3552 				sbi->s_want_extra_isize =
3553 					le16_to_cpu(es->s_want_extra_isize);
3554 			if (sbi->s_want_extra_isize <
3555 			    le16_to_cpu(es->s_min_extra_isize))
3556 				sbi->s_want_extra_isize =
3557 					le16_to_cpu(es->s_min_extra_isize);
3558 		}
3559 	}
3560 	/* Check if enough inode space is available */
3561 	if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3562 							sbi->s_inode_size) {
3563 		sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3564 						       EXT4_GOOD_OLD_INODE_SIZE;
3565 		ext4_msg(sb, KERN_INFO, "required extra inode space not"
3566 			 "available");
3567 	}
3568 
3569 	if (test_opt(sb, DELALLOC) &&
3570 	    (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
3571 		ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
3572 			 "requested data journaling mode");
3573 		clear_opt(sb, DELALLOC);
3574 	}
3575 	if (test_opt(sb, DIOREAD_NOLOCK)) {
3576 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3577 			ext4_msg(sb, KERN_WARNING, "Ignoring dioread_nolock "
3578 				"option - requested data journaling mode");
3579 			clear_opt(sb, DIOREAD_NOLOCK);
3580 		}
3581 		if (sb->s_blocksize < PAGE_SIZE) {
3582 			ext4_msg(sb, KERN_WARNING, "Ignoring dioread_nolock "
3583 				"option - block size is too small");
3584 			clear_opt(sb, DIOREAD_NOLOCK);
3585 		}
3586 	}
3587 
3588 	err = ext4_setup_system_zone(sb);
3589 	if (err) {
3590 		ext4_msg(sb, KERN_ERR, "failed to initialize system "
3591 			 "zone (%d)", err);
3592 		goto failed_mount4;
3593 	}
3594 
3595 	ext4_ext_init(sb);
3596 	err = ext4_mb_init(sb, needs_recovery);
3597 	if (err) {
3598 		ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3599 			 err);
3600 		goto failed_mount4;
3601 	}
3602 
3603 	err = ext4_register_li_request(sb, first_not_zeroed);
3604 	if (err)
3605 		goto failed_mount4;
3606 
3607 	sbi->s_kobj.kset = ext4_kset;
3608 	init_completion(&sbi->s_kobj_unregister);
3609 	err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3610 				   "%s", sb->s_id);
3611 	if (err) {
3612 		ext4_mb_release(sb);
3613 		ext4_ext_release(sb);
3614 		goto failed_mount4;
3615 	};
3616 
3617 	EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3618 	ext4_orphan_cleanup(sb, es);
3619 	EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3620 	if (needs_recovery) {
3621 		ext4_msg(sb, KERN_INFO, "recovery complete");
3622 		ext4_mark_recovery_complete(sb, es);
3623 	}
3624 	if (EXT4_SB(sb)->s_journal) {
3625 		if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3626 			descr = " journalled data mode";
3627 		else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3628 			descr = " ordered data mode";
3629 		else
3630 			descr = " writeback data mode";
3631 	} else
3632 		descr = "out journal";
3633 
3634 	ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3635 		 "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3636 		 *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3637 
3638 	init_timer(&sbi->s_err_report);
3639 	sbi->s_err_report.function = print_daily_error_info;
3640 	sbi->s_err_report.data = (unsigned long) sb;
3641 	if (es->s_error_count)
3642 		mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3643 
3644 	kfree(orig_data);
3645 	return 0;
3646 
3647 cantfind_ext4:
3648 	if (!silent)
3649 		ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3650 	goto failed_mount;
3651 
3652 failed_mount4:
3653 	ext4_msg(sb, KERN_ERR, "mount failed");
3654 	destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3655 failed_mount_wq:
3656 	ext4_release_system_zone(sb);
3657 	if (sbi->s_journal) {
3658 		jbd2_journal_destroy(sbi->s_journal);
3659 		sbi->s_journal = NULL;
3660 	}
3661 failed_mount3:
3662 	if (sbi->s_flex_groups) {
3663 		if (is_vmalloc_addr(sbi->s_flex_groups))
3664 			vfree(sbi->s_flex_groups);
3665 		else
3666 			kfree(sbi->s_flex_groups);
3667 	}
3668 	percpu_counter_destroy(&sbi->s_freeblocks_counter);
3669 	percpu_counter_destroy(&sbi->s_freeinodes_counter);
3670 	percpu_counter_destroy(&sbi->s_dirs_counter);
3671 	percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
3672 failed_mount2:
3673 	for (i = 0; i < db_count; i++)
3674 		brelse(sbi->s_group_desc[i]);
3675 	kfree(sbi->s_group_desc);
3676 failed_mount:
3677 	if (sbi->s_proc) {
3678 		remove_proc_entry(sb->s_id, ext4_proc_root);
3679 	}
3680 #ifdef CONFIG_QUOTA
3681 	for (i = 0; i < MAXQUOTAS; i++)
3682 		kfree(sbi->s_qf_names[i]);
3683 #endif
3684 	ext4_blkdev_remove(sbi);
3685 	brelse(bh);
3686 out_fail:
3687 	sb->s_fs_info = NULL;
3688 	kfree(sbi->s_blockgroup_lock);
3689 	kfree(sbi);
3690 out_free_orig:
3691 	kfree(orig_data);
3692 	return ret;
3693 }
3694 
3695 /*
3696  * Setup any per-fs journal parameters now.  We'll do this both on
3697  * initial mount, once the journal has been initialised but before we've
3698  * done any recovery; and again on any subsequent remount.
3699  */
3700 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3701 {
3702 	struct ext4_sb_info *sbi = EXT4_SB(sb);
3703 
3704 	journal->j_commit_interval = sbi->s_commit_interval;
3705 	journal->j_min_batch_time = sbi->s_min_batch_time;
3706 	journal->j_max_batch_time = sbi->s_max_batch_time;
3707 
3708 	write_lock(&journal->j_state_lock);
3709 	if (test_opt(sb, BARRIER))
3710 		journal->j_flags |= JBD2_BARRIER;
3711 	else
3712 		journal->j_flags &= ~JBD2_BARRIER;
3713 	if (test_opt(sb, DATA_ERR_ABORT))
3714 		journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3715 	else
3716 		journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3717 	write_unlock(&journal->j_state_lock);
3718 }
3719 
3720 static journal_t *ext4_get_journal(struct super_block *sb,
3721 				   unsigned int journal_inum)
3722 {
3723 	struct inode *journal_inode;
3724 	journal_t *journal;
3725 
3726 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3727 
3728 	/* First, test for the existence of a valid inode on disk.  Bad
3729 	 * things happen if we iget() an unused inode, as the subsequent
3730 	 * iput() will try to delete it. */
3731 
3732 	journal_inode = ext4_iget(sb, journal_inum);
3733 	if (IS_ERR(journal_inode)) {
3734 		ext4_msg(sb, KERN_ERR, "no journal found");
3735 		return NULL;
3736 	}
3737 	if (!journal_inode->i_nlink) {
3738 		make_bad_inode(journal_inode);
3739 		iput(journal_inode);
3740 		ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3741 		return NULL;
3742 	}
3743 
3744 	jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3745 		  journal_inode, journal_inode->i_size);
3746 	if (!S_ISREG(journal_inode->i_mode)) {
3747 		ext4_msg(sb, KERN_ERR, "invalid journal inode");
3748 		iput(journal_inode);
3749 		return NULL;
3750 	}
3751 
3752 	journal = jbd2_journal_init_inode(journal_inode);
3753 	if (!journal) {
3754 		ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3755 		iput(journal_inode);
3756 		return NULL;
3757 	}
3758 	journal->j_private = sb;
3759 	ext4_init_journal_params(sb, journal);
3760 	return journal;
3761 }
3762 
3763 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3764 				       dev_t j_dev)
3765 {
3766 	struct buffer_head *bh;
3767 	journal_t *journal;
3768 	ext4_fsblk_t start;
3769 	ext4_fsblk_t len;
3770 	int hblock, blocksize;
3771 	ext4_fsblk_t sb_block;
3772 	unsigned long offset;
3773 	struct ext4_super_block *es;
3774 	struct block_device *bdev;
3775 
3776 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3777 
3778 	bdev = ext4_blkdev_get(j_dev, sb);
3779 	if (bdev == NULL)
3780 		return NULL;
3781 
3782 	blocksize = sb->s_blocksize;
3783 	hblock = bdev_logical_block_size(bdev);
3784 	if (blocksize < hblock) {
3785 		ext4_msg(sb, KERN_ERR,
3786 			"blocksize too small for journal device");
3787 		goto out_bdev;
3788 	}
3789 
3790 	sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3791 	offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3792 	set_blocksize(bdev, blocksize);
3793 	if (!(bh = __bread(bdev, sb_block, blocksize))) {
3794 		ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3795 		       "external journal");
3796 		goto out_bdev;
3797 	}
3798 
3799 	es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3800 	if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3801 	    !(le32_to_cpu(es->s_feature_incompat) &
3802 	      EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3803 		ext4_msg(sb, KERN_ERR, "external journal has "
3804 					"bad superblock");
3805 		brelse(bh);
3806 		goto out_bdev;
3807 	}
3808 
3809 	if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3810 		ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3811 		brelse(bh);
3812 		goto out_bdev;
3813 	}
3814 
3815 	len = ext4_blocks_count(es);
3816 	start = sb_block + 1;
3817 	brelse(bh);	/* we're done with the superblock */
3818 
3819 	journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3820 					start, len, blocksize);
3821 	if (!journal) {
3822 		ext4_msg(sb, KERN_ERR, "failed to create device journal");
3823 		goto out_bdev;
3824 	}
3825 	journal->j_private = sb;
3826 	ll_rw_block(READ, 1, &journal->j_sb_buffer);
3827 	wait_on_buffer(journal->j_sb_buffer);
3828 	if (!buffer_uptodate(journal->j_sb_buffer)) {
3829 		ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3830 		goto out_journal;
3831 	}
3832 	if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3833 		ext4_msg(sb, KERN_ERR, "External journal has more than one "
3834 					"user (unsupported) - %d",
3835 			be32_to_cpu(journal->j_superblock->s_nr_users));
3836 		goto out_journal;
3837 	}
3838 	EXT4_SB(sb)->journal_bdev = bdev;
3839 	ext4_init_journal_params(sb, journal);
3840 	return journal;
3841 
3842 out_journal:
3843 	jbd2_journal_destroy(journal);
3844 out_bdev:
3845 	ext4_blkdev_put(bdev);
3846 	return NULL;
3847 }
3848 
3849 static int ext4_load_journal(struct super_block *sb,
3850 			     struct ext4_super_block *es,
3851 			     unsigned long journal_devnum)
3852 {
3853 	journal_t *journal;
3854 	unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3855 	dev_t journal_dev;
3856 	int err = 0;
3857 	int really_read_only;
3858 
3859 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3860 
3861 	if (journal_devnum &&
3862 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3863 		ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3864 			"numbers have changed");
3865 		journal_dev = new_decode_dev(journal_devnum);
3866 	} else
3867 		journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3868 
3869 	really_read_only = bdev_read_only(sb->s_bdev);
3870 
3871 	/*
3872 	 * Are we loading a blank journal or performing recovery after a
3873 	 * crash?  For recovery, we need to check in advance whether we
3874 	 * can get read-write access to the device.
3875 	 */
3876 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3877 		if (sb->s_flags & MS_RDONLY) {
3878 			ext4_msg(sb, KERN_INFO, "INFO: recovery "
3879 					"required on readonly filesystem");
3880 			if (really_read_only) {
3881 				ext4_msg(sb, KERN_ERR, "write access "
3882 					"unavailable, cannot proceed");
3883 				return -EROFS;
3884 			}
3885 			ext4_msg(sb, KERN_INFO, "write access will "
3886 			       "be enabled during recovery");
3887 		}
3888 	}
3889 
3890 	if (journal_inum && journal_dev) {
3891 		ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3892 		       "and inode journals!");
3893 		return -EINVAL;
3894 	}
3895 
3896 	if (journal_inum) {
3897 		if (!(journal = ext4_get_journal(sb, journal_inum)))
3898 			return -EINVAL;
3899 	} else {
3900 		if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3901 			return -EINVAL;
3902 	}
3903 
3904 	if (!(journal->j_flags & JBD2_BARRIER))
3905 		ext4_msg(sb, KERN_INFO, "barriers disabled");
3906 
3907 	if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3908 		err = jbd2_journal_update_format(journal);
3909 		if (err)  {
3910 			ext4_msg(sb, KERN_ERR, "error updating journal");
3911 			jbd2_journal_destroy(journal);
3912 			return err;
3913 		}
3914 	}
3915 
3916 	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3917 		err = jbd2_journal_wipe(journal, !really_read_only);
3918 	if (!err) {
3919 		char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
3920 		if (save)
3921 			memcpy(save, ((char *) es) +
3922 			       EXT4_S_ERR_START, EXT4_S_ERR_LEN);
3923 		err = jbd2_journal_load(journal);
3924 		if (save)
3925 			memcpy(((char *) es) + EXT4_S_ERR_START,
3926 			       save, EXT4_S_ERR_LEN);
3927 		kfree(save);
3928 	}
3929 
3930 	if (err) {
3931 		ext4_msg(sb, KERN_ERR, "error loading journal");
3932 		jbd2_journal_destroy(journal);
3933 		return err;
3934 	}
3935 
3936 	EXT4_SB(sb)->s_journal = journal;
3937 	ext4_clear_journal_err(sb, es);
3938 
3939 	if (!really_read_only && journal_devnum &&
3940 	    journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3941 		es->s_journal_dev = cpu_to_le32(journal_devnum);
3942 
3943 		/* Make sure we flush the recovery flag to disk. */
3944 		ext4_commit_super(sb, 1);
3945 	}
3946 
3947 	return 0;
3948 }
3949 
3950 static int ext4_commit_super(struct super_block *sb, int sync)
3951 {
3952 	struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3953 	struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3954 	int error = 0;
3955 
3956 	if (!sbh)
3957 		return error;
3958 	if (buffer_write_io_error(sbh)) {
3959 		/*
3960 		 * Oh, dear.  A previous attempt to write the
3961 		 * superblock failed.  This could happen because the
3962 		 * USB device was yanked out.  Or it could happen to
3963 		 * be a transient write error and maybe the block will
3964 		 * be remapped.  Nothing we can do but to retry the
3965 		 * write and hope for the best.
3966 		 */
3967 		ext4_msg(sb, KERN_ERR, "previous I/O error to "
3968 		       "superblock detected");
3969 		clear_buffer_write_io_error(sbh);
3970 		set_buffer_uptodate(sbh);
3971 	}
3972 	/*
3973 	 * If the file system is mounted read-only, don't update the
3974 	 * superblock write time.  This avoids updating the superblock
3975 	 * write time when we are mounting the root file system
3976 	 * read/only but we need to replay the journal; at that point,
3977 	 * for people who are east of GMT and who make their clock
3978 	 * tick in localtime for Windows bug-for-bug compatibility,
3979 	 * the clock is set in the future, and this will cause e2fsck
3980 	 * to complain and force a full file system check.
3981 	 */
3982 	if (!(sb->s_flags & MS_RDONLY))
3983 		es->s_wtime = cpu_to_le32(get_seconds());
3984 	if (sb->s_bdev->bd_part)
3985 		es->s_kbytes_written =
3986 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
3987 			    ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3988 			      EXT4_SB(sb)->s_sectors_written_start) >> 1));
3989 	else
3990 		es->s_kbytes_written =
3991 			cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
3992 	ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3993 					   &EXT4_SB(sb)->s_freeblocks_counter));
3994 	es->s_free_inodes_count =
3995 		cpu_to_le32(percpu_counter_sum_positive(
3996 				&EXT4_SB(sb)->s_freeinodes_counter));
3997 	sb->s_dirt = 0;
3998 	BUFFER_TRACE(sbh, "marking dirty");
3999 	mark_buffer_dirty(sbh);
4000 	if (sync) {
4001 		error = sync_dirty_buffer(sbh);
4002 		if (error)
4003 			return error;
4004 
4005 		error = buffer_write_io_error(sbh);
4006 		if (error) {
4007 			ext4_msg(sb, KERN_ERR, "I/O error while writing "
4008 			       "superblock");
4009 			clear_buffer_write_io_error(sbh);
4010 			set_buffer_uptodate(sbh);
4011 		}
4012 	}
4013 	return error;
4014 }
4015 
4016 /*
4017  * Have we just finished recovery?  If so, and if we are mounting (or
4018  * remounting) the filesystem readonly, then we will end up with a
4019  * consistent fs on disk.  Record that fact.
4020  */
4021 static void ext4_mark_recovery_complete(struct super_block *sb,
4022 					struct ext4_super_block *es)
4023 {
4024 	journal_t *journal = EXT4_SB(sb)->s_journal;
4025 
4026 	if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4027 		BUG_ON(journal != NULL);
4028 		return;
4029 	}
4030 	jbd2_journal_lock_updates(journal);
4031 	if (jbd2_journal_flush(journal) < 0)
4032 		goto out;
4033 
4034 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4035 	    sb->s_flags & MS_RDONLY) {
4036 		EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4037 		ext4_commit_super(sb, 1);
4038 	}
4039 
4040 out:
4041 	jbd2_journal_unlock_updates(journal);
4042 }
4043 
4044 /*
4045  * If we are mounting (or read-write remounting) a filesystem whose journal
4046  * has recorded an error from a previous lifetime, move that error to the
4047  * main filesystem now.
4048  */
4049 static void ext4_clear_journal_err(struct super_block *sb,
4050 				   struct ext4_super_block *es)
4051 {
4052 	journal_t *journal;
4053 	int j_errno;
4054 	const char *errstr;
4055 
4056 	BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4057 
4058 	journal = EXT4_SB(sb)->s_journal;
4059 
4060 	/*
4061 	 * Now check for any error status which may have been recorded in the
4062 	 * journal by a prior ext4_error() or ext4_abort()
4063 	 */
4064 
4065 	j_errno = jbd2_journal_errno(journal);
4066 	if (j_errno) {
4067 		char nbuf[16];
4068 
4069 		errstr = ext4_decode_error(sb, j_errno, nbuf);
4070 		ext4_warning(sb, "Filesystem error recorded "
4071 			     "from previous mount: %s", errstr);
4072 		ext4_warning(sb, "Marking fs in need of filesystem check.");
4073 
4074 		EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4075 		es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4076 		ext4_commit_super(sb, 1);
4077 
4078 		jbd2_journal_clear_err(journal);
4079 	}
4080 }
4081 
4082 /*
4083  * Force the running and committing transactions to commit,
4084  * and wait on the commit.
4085  */
4086 int ext4_force_commit(struct super_block *sb)
4087 {
4088 	journal_t *journal;
4089 	int ret = 0;
4090 
4091 	if (sb->s_flags & MS_RDONLY)
4092 		return 0;
4093 
4094 	journal = EXT4_SB(sb)->s_journal;
4095 	if (journal) {
4096 		vfs_check_frozen(sb, SB_FREEZE_TRANS);
4097 		ret = ext4_journal_force_commit(journal);
4098 	}
4099 
4100 	return ret;
4101 }
4102 
4103 static void ext4_write_super(struct super_block *sb)
4104 {
4105 	lock_super(sb);
4106 	ext4_commit_super(sb, 1);
4107 	unlock_super(sb);
4108 }
4109 
4110 static int ext4_sync_fs(struct super_block *sb, int wait)
4111 {
4112 	int ret = 0;
4113 	tid_t target;
4114 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4115 
4116 	trace_ext4_sync_fs(sb, wait);
4117 	flush_workqueue(sbi->dio_unwritten_wq);
4118 	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4119 		if (wait)
4120 			jbd2_log_wait_commit(sbi->s_journal, target);
4121 	}
4122 	return ret;
4123 }
4124 
4125 /*
4126  * LVM calls this function before a (read-only) snapshot is created.  This
4127  * gives us a chance to flush the journal completely and mark the fs clean.
4128  */
4129 static int ext4_freeze(struct super_block *sb)
4130 {
4131 	int error = 0;
4132 	journal_t *journal;
4133 
4134 	if (sb->s_flags & MS_RDONLY)
4135 		return 0;
4136 
4137 	journal = EXT4_SB(sb)->s_journal;
4138 
4139 	/* Now we set up the journal barrier. */
4140 	jbd2_journal_lock_updates(journal);
4141 
4142 	/*
4143 	 * Don't clear the needs_recovery flag if we failed to flush
4144 	 * the journal.
4145 	 */
4146 	error = jbd2_journal_flush(journal);
4147 	if (error < 0)
4148 		goto out;
4149 
4150 	/* Journal blocked and flushed, clear needs_recovery flag. */
4151 	EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4152 	error = ext4_commit_super(sb, 1);
4153 out:
4154 	/* we rely on s_frozen to stop further updates */
4155 	jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4156 	return error;
4157 }
4158 
4159 /*
4160  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4161  * flag here, even though the filesystem is not technically dirty yet.
4162  */
4163 static int ext4_unfreeze(struct super_block *sb)
4164 {
4165 	if (sb->s_flags & MS_RDONLY)
4166 		return 0;
4167 
4168 	lock_super(sb);
4169 	/* Reset the needs_recovery flag before the fs is unlocked. */
4170 	EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4171 	ext4_commit_super(sb, 1);
4172 	unlock_super(sb);
4173 	return 0;
4174 }
4175 
4176 /*
4177  * Structure to save mount options for ext4_remount's benefit
4178  */
4179 struct ext4_mount_options {
4180 	unsigned long s_mount_opt;
4181 	unsigned long s_mount_opt2;
4182 	uid_t s_resuid;
4183 	gid_t s_resgid;
4184 	unsigned long s_commit_interval;
4185 	u32 s_min_batch_time, s_max_batch_time;
4186 #ifdef CONFIG_QUOTA
4187 	int s_jquota_fmt;
4188 	char *s_qf_names[MAXQUOTAS];
4189 #endif
4190 };
4191 
4192 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4193 {
4194 	struct ext4_super_block *es;
4195 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4196 	ext4_fsblk_t n_blocks_count = 0;
4197 	unsigned long old_sb_flags;
4198 	struct ext4_mount_options old_opts;
4199 	int enable_quota = 0;
4200 	ext4_group_t g;
4201 	unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4202 	int err;
4203 #ifdef CONFIG_QUOTA
4204 	int i;
4205 #endif
4206 	char *orig_data = kstrdup(data, GFP_KERNEL);
4207 
4208 	/* Store the original options */
4209 	lock_super(sb);
4210 	old_sb_flags = sb->s_flags;
4211 	old_opts.s_mount_opt = sbi->s_mount_opt;
4212 	old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4213 	old_opts.s_resuid = sbi->s_resuid;
4214 	old_opts.s_resgid = sbi->s_resgid;
4215 	old_opts.s_commit_interval = sbi->s_commit_interval;
4216 	old_opts.s_min_batch_time = sbi->s_min_batch_time;
4217 	old_opts.s_max_batch_time = sbi->s_max_batch_time;
4218 #ifdef CONFIG_QUOTA
4219 	old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4220 	for (i = 0; i < MAXQUOTAS; i++)
4221 		old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4222 #endif
4223 	if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4224 		journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4225 
4226 	/*
4227 	 * Allow the "check" option to be passed as a remount option.
4228 	 */
4229 	if (!parse_options(data, sb, NULL, &journal_ioprio,
4230 			   &n_blocks_count, 1)) {
4231 		err = -EINVAL;
4232 		goto restore_opts;
4233 	}
4234 
4235 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4236 		ext4_abort(sb, "Abort forced by user");
4237 
4238 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4239 		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4240 
4241 	es = sbi->s_es;
4242 
4243 	if (sbi->s_journal) {
4244 		ext4_init_journal_params(sb, sbi->s_journal);
4245 		set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4246 	}
4247 
4248 	if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
4249 		n_blocks_count > ext4_blocks_count(es)) {
4250 		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4251 			err = -EROFS;
4252 			goto restore_opts;
4253 		}
4254 
4255 		if (*flags & MS_RDONLY) {
4256 			err = dquot_suspend(sb, -1);
4257 			if (err < 0)
4258 				goto restore_opts;
4259 
4260 			/*
4261 			 * First of all, the unconditional stuff we have to do
4262 			 * to disable replay of the journal when we next remount
4263 			 */
4264 			sb->s_flags |= MS_RDONLY;
4265 
4266 			/*
4267 			 * OK, test if we are remounting a valid rw partition
4268 			 * readonly, and if so set the rdonly flag and then
4269 			 * mark the partition as valid again.
4270 			 */
4271 			if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4272 			    (sbi->s_mount_state & EXT4_VALID_FS))
4273 				es->s_state = cpu_to_le16(sbi->s_mount_state);
4274 
4275 			if (sbi->s_journal)
4276 				ext4_mark_recovery_complete(sb, es);
4277 		} else {
4278 			/* Make sure we can mount this feature set readwrite */
4279 			if (!ext4_feature_set_ok(sb, 0)) {
4280 				err = -EROFS;
4281 				goto restore_opts;
4282 			}
4283 			/*
4284 			 * Make sure the group descriptor checksums
4285 			 * are sane.  If they aren't, refuse to remount r/w.
4286 			 */
4287 			for (g = 0; g < sbi->s_groups_count; g++) {
4288 				struct ext4_group_desc *gdp =
4289 					ext4_get_group_desc(sb, g, NULL);
4290 
4291 				if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
4292 					ext4_msg(sb, KERN_ERR,
4293 	       "ext4_remount: Checksum for group %u failed (%u!=%u)",
4294 		g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4295 					       le16_to_cpu(gdp->bg_checksum));
4296 					err = -EINVAL;
4297 					goto restore_opts;
4298 				}
4299 			}
4300 
4301 			/*
4302 			 * If we have an unprocessed orphan list hanging
4303 			 * around from a previously readonly bdev mount,
4304 			 * require a full umount/remount for now.
4305 			 */
4306 			if (es->s_last_orphan) {
4307 				ext4_msg(sb, KERN_WARNING, "Couldn't "
4308 				       "remount RDWR because of unprocessed "
4309 				       "orphan inode list.  Please "
4310 				       "umount/remount instead");
4311 				err = -EINVAL;
4312 				goto restore_opts;
4313 			}
4314 
4315 			/*
4316 			 * Mounting a RDONLY partition read-write, so reread
4317 			 * and store the current valid flag.  (It may have
4318 			 * been changed by e2fsck since we originally mounted
4319 			 * the partition.)
4320 			 */
4321 			if (sbi->s_journal)
4322 				ext4_clear_journal_err(sb, es);
4323 			sbi->s_mount_state = le16_to_cpu(es->s_state);
4324 			if ((err = ext4_group_extend(sb, es, n_blocks_count)))
4325 				goto restore_opts;
4326 			if (!ext4_setup_super(sb, es, 0))
4327 				sb->s_flags &= ~MS_RDONLY;
4328 			enable_quota = 1;
4329 		}
4330 	}
4331 
4332 	/*
4333 	 * Reinitialize lazy itable initialization thread based on
4334 	 * current settings
4335 	 */
4336 	if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4337 		ext4_unregister_li_request(sb);
4338 	else {
4339 		ext4_group_t first_not_zeroed;
4340 		first_not_zeroed = ext4_has_uninit_itable(sb);
4341 		ext4_register_li_request(sb, first_not_zeroed);
4342 	}
4343 
4344 	ext4_setup_system_zone(sb);
4345 	if (sbi->s_journal == NULL)
4346 		ext4_commit_super(sb, 1);
4347 
4348 #ifdef CONFIG_QUOTA
4349 	/* Release old quota file names */
4350 	for (i = 0; i < MAXQUOTAS; i++)
4351 		if (old_opts.s_qf_names[i] &&
4352 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4353 			kfree(old_opts.s_qf_names[i]);
4354 #endif
4355 	unlock_super(sb);
4356 	if (enable_quota)
4357 		dquot_resume(sb, -1);
4358 
4359 	ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4360 	kfree(orig_data);
4361 	return 0;
4362 
4363 restore_opts:
4364 	sb->s_flags = old_sb_flags;
4365 	sbi->s_mount_opt = old_opts.s_mount_opt;
4366 	sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4367 	sbi->s_resuid = old_opts.s_resuid;
4368 	sbi->s_resgid = old_opts.s_resgid;
4369 	sbi->s_commit_interval = old_opts.s_commit_interval;
4370 	sbi->s_min_batch_time = old_opts.s_min_batch_time;
4371 	sbi->s_max_batch_time = old_opts.s_max_batch_time;
4372 #ifdef CONFIG_QUOTA
4373 	sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4374 	for (i = 0; i < MAXQUOTAS; i++) {
4375 		if (sbi->s_qf_names[i] &&
4376 		    old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4377 			kfree(sbi->s_qf_names[i]);
4378 		sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4379 	}
4380 #endif
4381 	unlock_super(sb);
4382 	kfree(orig_data);
4383 	return err;
4384 }
4385 
4386 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4387 {
4388 	struct super_block *sb = dentry->d_sb;
4389 	struct ext4_sb_info *sbi = EXT4_SB(sb);
4390 	struct ext4_super_block *es = sbi->s_es;
4391 	u64 fsid;
4392 
4393 	if (test_opt(sb, MINIX_DF)) {
4394 		sbi->s_overhead_last = 0;
4395 	} else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
4396 		ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4397 		ext4_fsblk_t overhead = 0;
4398 
4399 		/*
4400 		 * Compute the overhead (FS structures).  This is constant
4401 		 * for a given filesystem unless the number of block groups
4402 		 * changes so we cache the previous value until it does.
4403 		 */
4404 
4405 		/*
4406 		 * All of the blocks before first_data_block are
4407 		 * overhead
4408 		 */
4409 		overhead = le32_to_cpu(es->s_first_data_block);
4410 
4411 		/*
4412 		 * Add the overhead attributed to the superblock and
4413 		 * block group descriptors.  If the sparse superblocks
4414 		 * feature is turned on, then not all groups have this.
4415 		 */
4416 		for (i = 0; i < ngroups; i++) {
4417 			overhead += ext4_bg_has_super(sb, i) +
4418 				ext4_bg_num_gdb(sb, i);
4419 			cond_resched();
4420 		}
4421 
4422 		/*
4423 		 * Every block group has an inode bitmap, a block
4424 		 * bitmap, and an inode table.
4425 		 */
4426 		overhead += ngroups * (2 + sbi->s_itb_per_group);
4427 		sbi->s_overhead_last = overhead;
4428 		smp_wmb();
4429 		sbi->s_blocks_last = ext4_blocks_count(es);
4430 	}
4431 
4432 	buf->f_type = EXT4_SUPER_MAGIC;
4433 	buf->f_bsize = sb->s_blocksize;
4434 	buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
4435 	buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
4436 		       percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
4437 	buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4438 	if (buf->f_bfree < ext4_r_blocks_count(es))
4439 		buf->f_bavail = 0;
4440 	buf->f_files = le32_to_cpu(es->s_inodes_count);
4441 	buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4442 	buf->f_namelen = EXT4_NAME_LEN;
4443 	fsid = le64_to_cpup((void *)es->s_uuid) ^
4444 	       le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4445 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4446 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4447 
4448 	return 0;
4449 }
4450 
4451 /* Helper function for writing quotas on sync - we need to start transaction
4452  * before quota file is locked for write. Otherwise the are possible deadlocks:
4453  * Process 1                         Process 2
4454  * ext4_create()                     quota_sync()
4455  *   jbd2_journal_start()                  write_dquot()
4456  *   dquot_initialize()                         down(dqio_mutex)
4457  *     down(dqio_mutex)                    jbd2_journal_start()
4458  *
4459  */
4460 
4461 #ifdef CONFIG_QUOTA
4462 
4463 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4464 {
4465 	return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4466 }
4467 
4468 static int ext4_write_dquot(struct dquot *dquot)
4469 {
4470 	int ret, err;
4471 	handle_t *handle;
4472 	struct inode *inode;
4473 
4474 	inode = dquot_to_inode(dquot);
4475 	handle = ext4_journal_start(inode,
4476 				    EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4477 	if (IS_ERR(handle))
4478 		return PTR_ERR(handle);
4479 	ret = dquot_commit(dquot);
4480 	err = ext4_journal_stop(handle);
4481 	if (!ret)
4482 		ret = err;
4483 	return ret;
4484 }
4485 
4486 static int ext4_acquire_dquot(struct dquot *dquot)
4487 {
4488 	int ret, err;
4489 	handle_t *handle;
4490 
4491 	handle = ext4_journal_start(dquot_to_inode(dquot),
4492 				    EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4493 	if (IS_ERR(handle))
4494 		return PTR_ERR(handle);
4495 	ret = dquot_acquire(dquot);
4496 	err = ext4_journal_stop(handle);
4497 	if (!ret)
4498 		ret = err;
4499 	return ret;
4500 }
4501 
4502 static int ext4_release_dquot(struct dquot *dquot)
4503 {
4504 	int ret, err;
4505 	handle_t *handle;
4506 
4507 	handle = ext4_journal_start(dquot_to_inode(dquot),
4508 				    EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4509 	if (IS_ERR(handle)) {
4510 		/* Release dquot anyway to avoid endless cycle in dqput() */
4511 		dquot_release(dquot);
4512 		return PTR_ERR(handle);
4513 	}
4514 	ret = dquot_release(dquot);
4515 	err = ext4_journal_stop(handle);
4516 	if (!ret)
4517 		ret = err;
4518 	return ret;
4519 }
4520 
4521 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4522 {
4523 	/* Are we journaling quotas? */
4524 	if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4525 	    EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4526 		dquot_mark_dquot_dirty(dquot);
4527 		return ext4_write_dquot(dquot);
4528 	} else {
4529 		return dquot_mark_dquot_dirty(dquot);
4530 	}
4531 }
4532 
4533 static int ext4_write_info(struct super_block *sb, int type)
4534 {
4535 	int ret, err;
4536 	handle_t *handle;
4537 
4538 	/* Data block + inode block */
4539 	handle = ext4_journal_start(sb->s_root->d_inode, 2);
4540 	if (IS_ERR(handle))
4541 		return PTR_ERR(handle);
4542 	ret = dquot_commit_info(sb, type);
4543 	err = ext4_journal_stop(handle);
4544 	if (!ret)
4545 		ret = err;
4546 	return ret;
4547 }
4548 
4549 /*
4550  * Turn on quotas during mount time - we need to find
4551  * the quota file and such...
4552  */
4553 static int ext4_quota_on_mount(struct super_block *sb, int type)
4554 {
4555 	return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4556 					EXT4_SB(sb)->s_jquota_fmt, type);
4557 }
4558 
4559 /*
4560  * Standard function to be called on quota_on
4561  */
4562 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4563 			 struct path *path)
4564 {
4565 	int err;
4566 
4567 	if (!test_opt(sb, QUOTA))
4568 		return -EINVAL;
4569 
4570 	/* Quotafile not on the same filesystem? */
4571 	if (path->mnt->mnt_sb != sb)
4572 		return -EXDEV;
4573 	/* Journaling quota? */
4574 	if (EXT4_SB(sb)->s_qf_names[type]) {
4575 		/* Quotafile not in fs root? */
4576 		if (path->dentry->d_parent != sb->s_root)
4577 			ext4_msg(sb, KERN_WARNING,
4578 				"Quota file not on filesystem root. "
4579 				"Journaled quota will not work");
4580 	}
4581 
4582 	/*
4583 	 * When we journal data on quota file, we have to flush journal to see
4584 	 * all updates to the file when we bypass pagecache...
4585 	 */
4586 	if (EXT4_SB(sb)->s_journal &&
4587 	    ext4_should_journal_data(path->dentry->d_inode)) {
4588 		/*
4589 		 * We don't need to lock updates but journal_flush() could
4590 		 * otherwise be livelocked...
4591 		 */
4592 		jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4593 		err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4594 		jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4595 		if (err)
4596 			return err;
4597 	}
4598 
4599 	return dquot_quota_on(sb, type, format_id, path);
4600 }
4601 
4602 static int ext4_quota_off(struct super_block *sb, int type)
4603 {
4604 	/* Force all delayed allocation blocks to be allocated.
4605 	 * Caller already holds s_umount sem */
4606 	if (test_opt(sb, DELALLOC))
4607 		sync_filesystem(sb);
4608 
4609 	return dquot_quota_off(sb, type);
4610 }
4611 
4612 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4613  * acquiring the locks... As quota files are never truncated and quota code
4614  * itself serializes the operations (and noone else should touch the files)
4615  * we don't have to be afraid of races */
4616 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4617 			       size_t len, loff_t off)
4618 {
4619 	struct inode *inode = sb_dqopt(sb)->files[type];
4620 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4621 	int err = 0;
4622 	int offset = off & (sb->s_blocksize - 1);
4623 	int tocopy;
4624 	size_t toread;
4625 	struct buffer_head *bh;
4626 	loff_t i_size = i_size_read(inode);
4627 
4628 	if (off > i_size)
4629 		return 0;
4630 	if (off+len > i_size)
4631 		len = i_size-off;
4632 	toread = len;
4633 	while (toread > 0) {
4634 		tocopy = sb->s_blocksize - offset < toread ?
4635 				sb->s_blocksize - offset : toread;
4636 		bh = ext4_bread(NULL, inode, blk, 0, &err);
4637 		if (err)
4638 			return err;
4639 		if (!bh)	/* A hole? */
4640 			memset(data, 0, tocopy);
4641 		else
4642 			memcpy(data, bh->b_data+offset, tocopy);
4643 		brelse(bh);
4644 		offset = 0;
4645 		toread -= tocopy;
4646 		data += tocopy;
4647 		blk++;
4648 	}
4649 	return len;
4650 }
4651 
4652 /* Write to quotafile (we know the transaction is already started and has
4653  * enough credits) */
4654 static ssize_t ext4_quota_write(struct super_block *sb, int type,
4655 				const char *data, size_t len, loff_t off)
4656 {
4657 	struct inode *inode = sb_dqopt(sb)->files[type];
4658 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4659 	int err = 0;
4660 	int offset = off & (sb->s_blocksize - 1);
4661 	struct buffer_head *bh;
4662 	handle_t *handle = journal_current_handle();
4663 
4664 	if (EXT4_SB(sb)->s_journal && !handle) {
4665 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4666 			" cancelled because transaction is not started",
4667 			(unsigned long long)off, (unsigned long long)len);
4668 		return -EIO;
4669 	}
4670 	/*
4671 	 * Since we account only one data block in transaction credits,
4672 	 * then it is impossible to cross a block boundary.
4673 	 */
4674 	if (sb->s_blocksize - offset < len) {
4675 		ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4676 			" cancelled because not block aligned",
4677 			(unsigned long long)off, (unsigned long long)len);
4678 		return -EIO;
4679 	}
4680 
4681 	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
4682 	bh = ext4_bread(handle, inode, blk, 1, &err);
4683 	if (!bh)
4684 		goto out;
4685 	err = ext4_journal_get_write_access(handle, bh);
4686 	if (err) {
4687 		brelse(bh);
4688 		goto out;
4689 	}
4690 	lock_buffer(bh);
4691 	memcpy(bh->b_data+offset, data, len);
4692 	flush_dcache_page(bh->b_page);
4693 	unlock_buffer(bh);
4694 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
4695 	brelse(bh);
4696 out:
4697 	if (err) {
4698 		mutex_unlock(&inode->i_mutex);
4699 		return err;
4700 	}
4701 	if (inode->i_size < off + len) {
4702 		i_size_write(inode, off + len);
4703 		EXT4_I(inode)->i_disksize = inode->i_size;
4704 	}
4705 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4706 	ext4_mark_inode_dirty(handle, inode);
4707 	mutex_unlock(&inode->i_mutex);
4708 	return len;
4709 }
4710 
4711 #endif
4712 
4713 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
4714 		       const char *dev_name, void *data)
4715 {
4716 	return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
4717 }
4718 
4719 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4720 static struct file_system_type ext2_fs_type = {
4721 	.owner		= THIS_MODULE,
4722 	.name		= "ext2",
4723 	.mount		= ext4_mount,
4724 	.kill_sb	= kill_block_super,
4725 	.fs_flags	= FS_REQUIRES_DEV,
4726 };
4727 
4728 static inline void register_as_ext2(void)
4729 {
4730 	int err = register_filesystem(&ext2_fs_type);
4731 	if (err)
4732 		printk(KERN_WARNING
4733 		       "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4734 }
4735 
4736 static inline void unregister_as_ext2(void)
4737 {
4738 	unregister_filesystem(&ext2_fs_type);
4739 }
4740 MODULE_ALIAS("ext2");
4741 #else
4742 static inline void register_as_ext2(void) { }
4743 static inline void unregister_as_ext2(void) { }
4744 #endif
4745 
4746 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4747 static inline void register_as_ext3(void)
4748 {
4749 	int err = register_filesystem(&ext3_fs_type);
4750 	if (err)
4751 		printk(KERN_WARNING
4752 		       "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4753 }
4754 
4755 static inline void unregister_as_ext3(void)
4756 {
4757 	unregister_filesystem(&ext3_fs_type);
4758 }
4759 MODULE_ALIAS("ext3");
4760 #else
4761 static inline void register_as_ext3(void) { }
4762 static inline void unregister_as_ext3(void) { }
4763 #endif
4764 
4765 static struct file_system_type ext4_fs_type = {
4766 	.owner		= THIS_MODULE,
4767 	.name		= "ext4",
4768 	.mount		= ext4_mount,
4769 	.kill_sb	= kill_block_super,
4770 	.fs_flags	= FS_REQUIRES_DEV,
4771 };
4772 
4773 static int __init ext4_init_feat_adverts(void)
4774 {
4775 	struct ext4_features *ef;
4776 	int ret = -ENOMEM;
4777 
4778 	ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
4779 	if (!ef)
4780 		goto out;
4781 
4782 	ef->f_kobj.kset = ext4_kset;
4783 	init_completion(&ef->f_kobj_unregister);
4784 	ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
4785 				   "features");
4786 	if (ret) {
4787 		kfree(ef);
4788 		goto out;
4789 	}
4790 
4791 	ext4_feat = ef;
4792 	ret = 0;
4793 out:
4794 	return ret;
4795 }
4796 
4797 static void ext4_exit_feat_adverts(void)
4798 {
4799 	kobject_put(&ext4_feat->f_kobj);
4800 	wait_for_completion(&ext4_feat->f_kobj_unregister);
4801 	kfree(ext4_feat);
4802 }
4803 
4804 /* Shared across all ext4 file systems */
4805 wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
4806 struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
4807 
4808 static int __init ext4_init_fs(void)
4809 {
4810 	int i, err;
4811 
4812 	ext4_check_flag_values();
4813 
4814 	for (i = 0; i < EXT4_WQ_HASH_SZ; i++) {
4815 		mutex_init(&ext4__aio_mutex[i]);
4816 		init_waitqueue_head(&ext4__ioend_wq[i]);
4817 	}
4818 
4819 	err = ext4_init_pageio();
4820 	if (err)
4821 		return err;
4822 	err = ext4_init_system_zone();
4823 	if (err)
4824 		goto out7;
4825 	ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
4826 	if (!ext4_kset)
4827 		goto out6;
4828 	ext4_proc_root = proc_mkdir("fs/ext4", NULL);
4829 	if (!ext4_proc_root)
4830 		goto out5;
4831 
4832 	err = ext4_init_feat_adverts();
4833 	if (err)
4834 		goto out4;
4835 
4836 	err = ext4_init_mballoc();
4837 	if (err)
4838 		goto out3;
4839 
4840 	err = ext4_init_xattr();
4841 	if (err)
4842 		goto out2;
4843 	err = init_inodecache();
4844 	if (err)
4845 		goto out1;
4846 	register_as_ext2();
4847 	register_as_ext3();
4848 	err = register_filesystem(&ext4_fs_type);
4849 	if (err)
4850 		goto out;
4851 
4852 	ext4_li_info = NULL;
4853 	mutex_init(&ext4_li_mtx);
4854 	return 0;
4855 out:
4856 	unregister_as_ext2();
4857 	unregister_as_ext3();
4858 	destroy_inodecache();
4859 out1:
4860 	ext4_exit_xattr();
4861 out2:
4862 	ext4_exit_mballoc();
4863 out3:
4864 	ext4_exit_feat_adverts();
4865 out4:
4866 	remove_proc_entry("fs/ext4", NULL);
4867 out5:
4868 	kset_unregister(ext4_kset);
4869 out6:
4870 	ext4_exit_system_zone();
4871 out7:
4872 	ext4_exit_pageio();
4873 	return err;
4874 }
4875 
4876 static void __exit ext4_exit_fs(void)
4877 {
4878 	ext4_destroy_lazyinit_thread();
4879 	unregister_as_ext2();
4880 	unregister_as_ext3();
4881 	unregister_filesystem(&ext4_fs_type);
4882 	destroy_inodecache();
4883 	ext4_exit_xattr();
4884 	ext4_exit_mballoc();
4885 	ext4_exit_feat_adverts();
4886 	remove_proc_entry("fs/ext4", NULL);
4887 	kset_unregister(ext4_kset);
4888 	ext4_exit_system_zone();
4889 	ext4_exit_pageio();
4890 }
4891 
4892 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4893 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4894 MODULE_LICENSE("GPL");
4895 module_init(ext4_init_fs)
4896 module_exit(ext4_exit_fs)
4897