2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/blkdev.h>
20 #include <linux/module.h>
21 #include <linux/buffer_head.h>
23 #include <linux/pagemap.h>
24 #include <linux/highmem.h>
25 #include <linux/time.h>
26 #include <linux/init.h>
27 #include <linux/seq_file.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mount.h>
31 #include <linux/mpage.h>
32 #include <linux/swap.h>
33 #include <linux/writeback.h>
34 #include <linux/statfs.h>
35 #include <linux/compat.h>
36 #include <linux/parser.h>
37 #include <linux/ctype.h>
38 #include <linux/namei.h>
39 #include <linux/miscdevice.h>
40 #include <linux/magic.h>
41 #include <linux/slab.h>
42 #include <linux/cleancache.h>
43 #include <linux/ratelimit.h>
45 #include "delayed-inode.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
51 #include "print-tree.h"
56 #include "compression.h"
58 #define CREATE_TRACE_POINTS
59 #include <trace/events/btrfs.h>
61 static const struct super_operations btrfs_super_ops
;
62 static struct file_system_type btrfs_fs_type
;
64 static const char *btrfs_decode_error(struct btrfs_fs_info
*fs_info
, int errno
,
71 errstr
= "IO failure";
74 errstr
= "Out of memory";
77 errstr
= "Readonly filesystem";
80 errstr
= "Object already exists";
84 if (snprintf(nbuf
, 16, "error %d", -errno
) >= 0)
93 static void __save_error_info(struct btrfs_fs_info
*fs_info
)
96 * today we only save the error info into ram. Long term we'll
97 * also send it down to the disk
99 fs_info
->fs_state
= BTRFS_SUPER_FLAG_ERROR
;
103 * We move write_super stuff at umount in order to avoid deadlock
104 * for umount hold all lock.
106 static void save_error_info(struct btrfs_fs_info
*fs_info
)
108 __save_error_info(fs_info
);
111 /* btrfs handle error by forcing the filesystem readonly */
112 static void btrfs_handle_error(struct btrfs_fs_info
*fs_info
)
114 struct super_block
*sb
= fs_info
->sb
;
116 if (sb
->s_flags
& MS_RDONLY
)
119 if (fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
120 sb
->s_flags
|= MS_RDONLY
;
121 printk(KERN_INFO
"btrfs is forced readonly\n");
122 __btrfs_scrub_cancel(fs_info
);
128 * __btrfs_std_error decodes expected errors from the caller and
129 * invokes the approciate error response.
131 void __btrfs_std_error(struct btrfs_fs_info
*fs_info
, const char *function
,
132 unsigned int line
, int errno
, const char *fmt
, ...)
134 struct super_block
*sb
= fs_info
->sb
;
141 * Special case: if the error is EROFS, and we're already
142 * under MS_RDONLY, then it is safe here.
144 if (errno
== -EROFS
&& (sb
->s_flags
& MS_RDONLY
))
147 errstr
= btrfs_decode_error(fs_info
, errno
, nbuf
);
149 struct va_format vaf
= {
154 printk(KERN_CRIT
"BTRFS error (device %s) in %s:%d: %s (%pV)\n",
155 sb
->s_id
, function
, line
, errstr
, &vaf
);
157 printk(KERN_CRIT
"BTRFS error (device %s) in %s:%d: %s\n",
158 sb
->s_id
, function
, line
, errstr
);
161 /* Don't go through full error handling during mount */
162 if (sb
->s_flags
& MS_BORN
) {
163 save_error_info(fs_info
);
164 btrfs_handle_error(fs_info
);
169 const char *logtypes
[] = {
180 void btrfs_printk(struct btrfs_fs_info
*fs_info
, const char *fmt
, ...)
182 struct super_block
*sb
= fs_info
->sb
;
184 struct va_format vaf
;
186 const char *type
= logtypes
[4];
190 if (fmt
[0] == '<' && isdigit(fmt
[1]) && fmt
[2] == '>') {
191 strncpy(lvl
, fmt
, 3);
193 type
= logtypes
[fmt
[1] - '0'];
199 printk("%sBTRFS %s (device %s): %pV", lvl
, type
, sb
->s_id
, &vaf
);
203 * We only mark the transaction aborted and then set the file system read-only.
204 * This will prevent new transactions from starting or trying to join this
207 * This means that error recovery at the call site is limited to freeing
208 * any local memory allocations and passing the error code up without
209 * further cleanup. The transaction should complete as it normally would
210 * in the call path but will return -EIO.
212 * We'll complete the cleanup in btrfs_end_transaction and
213 * btrfs_commit_transaction.
215 void __btrfs_abort_transaction(struct btrfs_trans_handle
*trans
,
216 struct btrfs_root
*root
, const char *function
,
217 unsigned int line
, int errno
)
219 WARN_ONCE(1, KERN_DEBUG
"btrfs: Transaction aborted");
220 trans
->aborted
= errno
;
221 /* Nothing used. The other threads that have joined this
222 * transaction may be able to continue. */
223 if (!trans
->blocks_used
) {
224 btrfs_printk(root
->fs_info
, "Aborting unused transaction.\n");
227 trans
->transaction
->aborted
= errno
;
228 __btrfs_std_error(root
->fs_info
, function
, line
, errno
, NULL
);
231 * __btrfs_panic decodes unexpected, fatal errors from the caller,
232 * issues an alert, and either panics or BUGs, depending on mount options.
234 void __btrfs_panic(struct btrfs_fs_info
*fs_info
, const char *function
,
235 unsigned int line
, int errno
, const char *fmt
, ...)
238 char *s_id
= "<unknown>";
240 struct va_format vaf
= { .fmt
= fmt
};
244 s_id
= fs_info
->sb
->s_id
;
249 errstr
= btrfs_decode_error(fs_info
, errno
, nbuf
);
250 if (fs_info
->mount_opt
& BTRFS_MOUNT_PANIC_ON_FATAL_ERROR
)
251 panic(KERN_CRIT
"BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
252 s_id
, function
, line
, &vaf
, errstr
);
254 printk(KERN_CRIT
"BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
255 s_id
, function
, line
, &vaf
, errstr
);
257 /* Caller calls BUG() */
260 static void btrfs_put_super(struct super_block
*sb
)
262 (void)close_ctree(btrfs_sb(sb
)->tree_root
);
263 /* FIXME: need to fix VFS to return error? */
264 /* AV: return it _where_? ->put_super() can be triggered by any number
265 * of async events, up to and including delivery of SIGKILL to the
266 * last process that kept it busy. Or segfault in the aforementioned
267 * process... Whom would you report that to?
272 Opt_degraded
, Opt_subvol
, Opt_subvolid
, Opt_device
, Opt_nodatasum
,
273 Opt_nodatacow
, Opt_max_inline
, Opt_alloc_start
, Opt_nobarrier
, Opt_ssd
,
274 Opt_nossd
, Opt_ssd_spread
, Opt_thread_pool
, Opt_noacl
, Opt_compress
,
275 Opt_compress_type
, Opt_compress_force
, Opt_compress_force_type
,
276 Opt_notreelog
, Opt_ratio
, Opt_flushoncommit
, Opt_discard
,
277 Opt_space_cache
, Opt_clear_cache
, Opt_user_subvol_rm_allowed
,
278 Opt_enospc_debug
, Opt_subvolrootid
, Opt_defrag
, Opt_inode_cache
,
279 Opt_no_space_cache
, Opt_recovery
, Opt_skip_balance
,
280 Opt_check_integrity
, Opt_check_integrity_including_extent_data
,
281 Opt_check_integrity_print_mask
, Opt_fatal_errors
,
285 static match_table_t tokens
= {
286 {Opt_degraded
, "degraded"},
287 {Opt_subvol
, "subvol=%s"},
288 {Opt_subvolid
, "subvolid=%d"},
289 {Opt_device
, "device=%s"},
290 {Opt_nodatasum
, "nodatasum"},
291 {Opt_nodatacow
, "nodatacow"},
292 {Opt_nobarrier
, "nobarrier"},
293 {Opt_max_inline
, "max_inline=%s"},
294 {Opt_alloc_start
, "alloc_start=%s"},
295 {Opt_thread_pool
, "thread_pool=%d"},
296 {Opt_compress
, "compress"},
297 {Opt_compress_type
, "compress=%s"},
298 {Opt_compress_force
, "compress-force"},
299 {Opt_compress_force_type
, "compress-force=%s"},
301 {Opt_ssd_spread
, "ssd_spread"},
302 {Opt_nossd
, "nossd"},
303 {Opt_noacl
, "noacl"},
304 {Opt_notreelog
, "notreelog"},
305 {Opt_flushoncommit
, "flushoncommit"},
306 {Opt_ratio
, "metadata_ratio=%d"},
307 {Opt_discard
, "discard"},
308 {Opt_space_cache
, "space_cache"},
309 {Opt_clear_cache
, "clear_cache"},
310 {Opt_user_subvol_rm_allowed
, "user_subvol_rm_allowed"},
311 {Opt_enospc_debug
, "enospc_debug"},
312 {Opt_subvolrootid
, "subvolrootid=%d"},
313 {Opt_defrag
, "autodefrag"},
314 {Opt_inode_cache
, "inode_cache"},
315 {Opt_no_space_cache
, "nospace_cache"},
316 {Opt_recovery
, "recovery"},
317 {Opt_skip_balance
, "skip_balance"},
318 {Opt_check_integrity
, "check_int"},
319 {Opt_check_integrity_including_extent_data
, "check_int_data"},
320 {Opt_check_integrity_print_mask
, "check_int_print_mask=%d"},
321 {Opt_fatal_errors
, "fatal_errors=%s"},
326 * Regular mount options parser. Everything that is needed only when
327 * reading in a new superblock is parsed here.
328 * XXX JDM: This needs to be cleaned up for remount.
330 int btrfs_parse_options(struct btrfs_root
*root
, char *options
)
332 struct btrfs_fs_info
*info
= root
->fs_info
;
333 substring_t args
[MAX_OPT_ARGS
];
334 char *p
, *num
, *orig
= NULL
;
339 bool compress_force
= false;
341 cache_gen
= btrfs_super_cache_generation(root
->fs_info
->super_copy
);
343 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
349 * strsep changes the string, duplicate it because parse_options
352 options
= kstrdup(options
, GFP_NOFS
);
358 while ((p
= strsep(&options
, ",")) != NULL
) {
363 token
= match_token(p
, tokens
, args
);
366 printk(KERN_INFO
"btrfs: allowing degraded mounts\n");
367 btrfs_set_opt(info
->mount_opt
, DEGRADED
);
371 case Opt_subvolrootid
:
374 * These are parsed by btrfs_parse_early_options
375 * and can be happily ignored here.
379 printk(KERN_INFO
"btrfs: setting nodatasum\n");
380 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
383 printk(KERN_INFO
"btrfs: setting nodatacow\n");
384 btrfs_set_opt(info
->mount_opt
, NODATACOW
);
385 btrfs_set_opt(info
->mount_opt
, NODATASUM
);
387 case Opt_compress_force
:
388 case Opt_compress_force_type
:
389 compress_force
= true;
391 case Opt_compress_type
:
392 if (token
== Opt_compress
||
393 token
== Opt_compress_force
||
394 strcmp(args
[0].from
, "zlib") == 0) {
395 compress_type
= "zlib";
396 info
->compress_type
= BTRFS_COMPRESS_ZLIB
;
397 } else if (strcmp(args
[0].from
, "lzo") == 0) {
398 compress_type
= "lzo";
399 info
->compress_type
= BTRFS_COMPRESS_LZO
;
405 btrfs_set_opt(info
->mount_opt
, COMPRESS
);
406 if (compress_force
) {
407 btrfs_set_opt(info
->mount_opt
, FORCE_COMPRESS
);
408 pr_info("btrfs: force %s compression\n",
411 pr_info("btrfs: use %s compression\n",
415 printk(KERN_INFO
"btrfs: use ssd allocation scheme\n");
416 btrfs_set_opt(info
->mount_opt
, SSD
);
419 printk(KERN_INFO
"btrfs: use spread ssd "
420 "allocation scheme\n");
421 btrfs_set_opt(info
->mount_opt
, SSD
);
422 btrfs_set_opt(info
->mount_opt
, SSD_SPREAD
);
425 printk(KERN_INFO
"btrfs: not using ssd allocation "
427 btrfs_set_opt(info
->mount_opt
, NOSSD
);
428 btrfs_clear_opt(info
->mount_opt
, SSD
);
429 btrfs_clear_opt(info
->mount_opt
, SSD_SPREAD
);
432 printk(KERN_INFO
"btrfs: turning off barriers\n");
433 btrfs_set_opt(info
->mount_opt
, NOBARRIER
);
435 case Opt_thread_pool
:
437 match_int(&args
[0], &intarg
);
439 info
->thread_pool_size
= intarg
;
440 printk(KERN_INFO
"btrfs: thread pool %d\n",
441 info
->thread_pool_size
);
445 num
= match_strdup(&args
[0]);
447 info
->max_inline
= memparse(num
, NULL
);
450 if (info
->max_inline
) {
451 info
->max_inline
= max_t(u64
,
455 printk(KERN_INFO
"btrfs: max_inline at %llu\n",
456 (unsigned long long)info
->max_inline
);
459 case Opt_alloc_start
:
460 num
= match_strdup(&args
[0]);
462 info
->alloc_start
= memparse(num
, NULL
);
465 "btrfs: allocations start at %llu\n",
466 (unsigned long long)info
->alloc_start
);
470 root
->fs_info
->sb
->s_flags
&= ~MS_POSIXACL
;
473 printk(KERN_INFO
"btrfs: disabling tree log\n");
474 btrfs_set_opt(info
->mount_opt
, NOTREELOG
);
476 case Opt_flushoncommit
:
477 printk(KERN_INFO
"btrfs: turning on flush-on-commit\n");
478 btrfs_set_opt(info
->mount_opt
, FLUSHONCOMMIT
);
482 match_int(&args
[0], &intarg
);
484 info
->metadata_ratio
= intarg
;
485 printk(KERN_INFO
"btrfs: metadata ratio %d\n",
486 info
->metadata_ratio
);
490 btrfs_set_opt(info
->mount_opt
, DISCARD
);
492 case Opt_space_cache
:
493 btrfs_set_opt(info
->mount_opt
, SPACE_CACHE
);
495 case Opt_no_space_cache
:
496 printk(KERN_INFO
"btrfs: disabling disk space caching\n");
497 btrfs_clear_opt(info
->mount_opt
, SPACE_CACHE
);
499 case Opt_inode_cache
:
500 printk(KERN_INFO
"btrfs: enabling inode map caching\n");
501 btrfs_set_opt(info
->mount_opt
, INODE_MAP_CACHE
);
503 case Opt_clear_cache
:
504 printk(KERN_INFO
"btrfs: force clearing of disk cache\n");
505 btrfs_set_opt(info
->mount_opt
, CLEAR_CACHE
);
507 case Opt_user_subvol_rm_allowed
:
508 btrfs_set_opt(info
->mount_opt
, USER_SUBVOL_RM_ALLOWED
);
510 case Opt_enospc_debug
:
511 btrfs_set_opt(info
->mount_opt
, ENOSPC_DEBUG
);
514 printk(KERN_INFO
"btrfs: enabling auto defrag");
515 btrfs_set_opt(info
->mount_opt
, AUTO_DEFRAG
);
518 printk(KERN_INFO
"btrfs: enabling auto recovery");
519 btrfs_set_opt(info
->mount_opt
, RECOVERY
);
521 case Opt_skip_balance
:
522 btrfs_set_opt(info
->mount_opt
, SKIP_BALANCE
);
524 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
525 case Opt_check_integrity_including_extent_data
:
526 printk(KERN_INFO
"btrfs: enabling check integrity"
527 " including extent data\n");
528 btrfs_set_opt(info
->mount_opt
,
529 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA
);
530 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
532 case Opt_check_integrity
:
533 printk(KERN_INFO
"btrfs: enabling check integrity\n");
534 btrfs_set_opt(info
->mount_opt
, CHECK_INTEGRITY
);
536 case Opt_check_integrity_print_mask
:
538 match_int(&args
[0], &intarg
);
540 info
->check_integrity_print_mask
= intarg
;
541 printk(KERN_INFO
"btrfs:"
542 " check_integrity_print_mask 0x%x\n",
543 info
->check_integrity_print_mask
);
547 case Opt_check_integrity_including_extent_data
:
548 case Opt_check_integrity
:
549 case Opt_check_integrity_print_mask
:
550 printk(KERN_ERR
"btrfs: support for check_integrity*"
551 " not compiled in!\n");
555 case Opt_fatal_errors
:
556 if (strcmp(args
[0].from
, "panic") == 0)
557 btrfs_set_opt(info
->mount_opt
,
558 PANIC_ON_FATAL_ERROR
);
559 else if (strcmp(args
[0].from
, "bug") == 0)
560 btrfs_clear_opt(info
->mount_opt
,
561 PANIC_ON_FATAL_ERROR
);
568 printk(KERN_INFO
"btrfs: unrecognized mount option "
577 if (!ret
&& btrfs_test_opt(root
, SPACE_CACHE
))
578 printk(KERN_INFO
"btrfs: disk space caching is enabled\n");
584 * Parse mount options that are required early in the mount process.
586 * All other options will be parsed on much later in the mount process and
587 * only when we need to allocate a new super block.
589 static int btrfs_parse_early_options(const char *options
, fmode_t flags
,
590 void *holder
, char **subvol_name
, u64
*subvol_objectid
,
591 u64
*subvol_rootid
, struct btrfs_fs_devices
**fs_devices
)
593 substring_t args
[MAX_OPT_ARGS
];
594 char *device_name
, *opts
, *orig
, *p
;
602 * strsep changes the string, duplicate it because parse_options
605 opts
= kstrdup(options
, GFP_KERNEL
);
610 while ((p
= strsep(&opts
, ",")) != NULL
) {
615 token
= match_token(p
, tokens
, args
);
619 *subvol_name
= match_strdup(&args
[0]);
623 error
= match_int(&args
[0], &intarg
);
625 /* we want the original fs_tree */
628 BTRFS_FS_TREE_OBJECTID
;
630 *subvol_objectid
= intarg
;
633 case Opt_subvolrootid
:
635 error
= match_int(&args
[0], &intarg
);
637 /* we want the original fs_tree */
640 BTRFS_FS_TREE_OBJECTID
;
642 *subvol_rootid
= intarg
;
646 device_name
= match_strdup(&args
[0]);
651 error
= btrfs_scan_one_device(device_name
,
652 flags
, holder
, fs_devices
);
667 static struct dentry
*get_default_root(struct super_block
*sb
,
670 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
671 struct btrfs_root
*root
= fs_info
->tree_root
;
672 struct btrfs_root
*new_root
;
673 struct btrfs_dir_item
*di
;
674 struct btrfs_path
*path
;
675 struct btrfs_key location
;
681 * We have a specific subvol we want to mount, just setup location and
682 * go look up the root.
684 if (subvol_objectid
) {
685 location
.objectid
= subvol_objectid
;
686 location
.type
= BTRFS_ROOT_ITEM_KEY
;
687 location
.offset
= (u64
)-1;
691 path
= btrfs_alloc_path();
693 return ERR_PTR(-ENOMEM
);
694 path
->leave_spinning
= 1;
697 * Find the "default" dir item which points to the root item that we
698 * will mount by default if we haven't been given a specific subvolume
701 dir_id
= btrfs_super_root_dir(fs_info
->super_copy
);
702 di
= btrfs_lookup_dir_item(NULL
, root
, path
, dir_id
, "default", 7, 0);
704 btrfs_free_path(path
);
709 * Ok the default dir item isn't there. This is weird since
710 * it's always been there, but don't freak out, just try and
711 * mount to root most subvolume.
713 btrfs_free_path(path
);
714 dir_id
= BTRFS_FIRST_FREE_OBJECTID
;
715 new_root
= fs_info
->fs_root
;
719 btrfs_dir_item_key_to_cpu(path
->nodes
[0], di
, &location
);
720 btrfs_free_path(path
);
723 new_root
= btrfs_read_fs_root_no_name(fs_info
, &location
);
724 if (IS_ERR(new_root
))
725 return ERR_CAST(new_root
);
727 if (btrfs_root_refs(&new_root
->root_item
) == 0)
728 return ERR_PTR(-ENOENT
);
730 dir_id
= btrfs_root_dirid(&new_root
->root_item
);
732 location
.objectid
= dir_id
;
733 location
.type
= BTRFS_INODE_ITEM_KEY
;
736 inode
= btrfs_iget(sb
, &location
, new_root
, &new);
738 return ERR_CAST(inode
);
741 * If we're just mounting the root most subvol put the inode and return
742 * a reference to the dentry. We will have already gotten a reference
743 * to the inode in btrfs_fill_super so we're good to go.
745 if (!new && sb
->s_root
->d_inode
== inode
) {
747 return dget(sb
->s_root
);
750 return d_obtain_alias(inode
);
753 static int btrfs_fill_super(struct super_block
*sb
,
754 struct btrfs_fs_devices
*fs_devices
,
755 void *data
, int silent
)
758 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
759 struct btrfs_key key
;
762 sb
->s_maxbytes
= MAX_LFS_FILESIZE
;
763 sb
->s_magic
= BTRFS_SUPER_MAGIC
;
764 sb
->s_op
= &btrfs_super_ops
;
765 sb
->s_d_op
= &btrfs_dentry_operations
;
766 sb
->s_export_op
= &btrfs_export_ops
;
767 sb
->s_xattr
= btrfs_xattr_handlers
;
769 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
770 sb
->s_flags
|= MS_POSIXACL
;
773 err
= open_ctree(sb
, fs_devices
, (char *)data
);
775 printk("btrfs: open_ctree failed\n");
779 key
.objectid
= BTRFS_FIRST_FREE_OBJECTID
;
780 key
.type
= BTRFS_INODE_ITEM_KEY
;
782 inode
= btrfs_iget(sb
, &key
, fs_info
->fs_root
, NULL
);
784 err
= PTR_ERR(inode
);
788 sb
->s_root
= d_make_root(inode
);
794 save_mount_options(sb
, data
);
795 cleancache_init_fs(sb
);
796 sb
->s_flags
|= MS_ACTIVE
;
800 close_ctree(fs_info
->tree_root
);
804 int btrfs_sync_fs(struct super_block
*sb
, int wait
)
806 struct btrfs_trans_handle
*trans
;
807 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
808 struct btrfs_root
*root
= fs_info
->tree_root
;
811 trace_btrfs_sync_fs(wait
);
814 filemap_flush(fs_info
->btree_inode
->i_mapping
);
818 btrfs_wait_ordered_extents(root
, 0, 0);
820 trans
= btrfs_start_transaction(root
, 0);
822 return PTR_ERR(trans
);
823 ret
= btrfs_commit_transaction(trans
, root
);
827 static int btrfs_show_options(struct seq_file
*seq
, struct dentry
*dentry
)
829 struct btrfs_fs_info
*info
= btrfs_sb(dentry
->d_sb
);
830 struct btrfs_root
*root
= info
->tree_root
;
833 if (btrfs_test_opt(root
, DEGRADED
))
834 seq_puts(seq
, ",degraded");
835 if (btrfs_test_opt(root
, NODATASUM
))
836 seq_puts(seq
, ",nodatasum");
837 if (btrfs_test_opt(root
, NODATACOW
))
838 seq_puts(seq
, ",nodatacow");
839 if (btrfs_test_opt(root
, NOBARRIER
))
840 seq_puts(seq
, ",nobarrier");
841 if (info
->max_inline
!= 8192 * 1024)
842 seq_printf(seq
, ",max_inline=%llu",
843 (unsigned long long)info
->max_inline
);
844 if (info
->alloc_start
!= 0)
845 seq_printf(seq
, ",alloc_start=%llu",
846 (unsigned long long)info
->alloc_start
);
847 if (info
->thread_pool_size
!= min_t(unsigned long,
848 num_online_cpus() + 2, 8))
849 seq_printf(seq
, ",thread_pool=%d", info
->thread_pool_size
);
850 if (btrfs_test_opt(root
, COMPRESS
)) {
851 if (info
->compress_type
== BTRFS_COMPRESS_ZLIB
)
852 compress_type
= "zlib";
854 compress_type
= "lzo";
855 if (btrfs_test_opt(root
, FORCE_COMPRESS
))
856 seq_printf(seq
, ",compress-force=%s", compress_type
);
858 seq_printf(seq
, ",compress=%s", compress_type
);
860 if (btrfs_test_opt(root
, NOSSD
))
861 seq_puts(seq
, ",nossd");
862 if (btrfs_test_opt(root
, SSD_SPREAD
))
863 seq_puts(seq
, ",ssd_spread");
864 else if (btrfs_test_opt(root
, SSD
))
865 seq_puts(seq
, ",ssd");
866 if (btrfs_test_opt(root
, NOTREELOG
))
867 seq_puts(seq
, ",notreelog");
868 if (btrfs_test_opt(root
, FLUSHONCOMMIT
))
869 seq_puts(seq
, ",flushoncommit");
870 if (btrfs_test_opt(root
, DISCARD
))
871 seq_puts(seq
, ",discard");
872 if (!(root
->fs_info
->sb
->s_flags
& MS_POSIXACL
))
873 seq_puts(seq
, ",noacl");
874 if (btrfs_test_opt(root
, SPACE_CACHE
))
875 seq_puts(seq
, ",space_cache");
877 seq_puts(seq
, ",nospace_cache");
878 if (btrfs_test_opt(root
, CLEAR_CACHE
))
879 seq_puts(seq
, ",clear_cache");
880 if (btrfs_test_opt(root
, USER_SUBVOL_RM_ALLOWED
))
881 seq_puts(seq
, ",user_subvol_rm_allowed");
882 if (btrfs_test_opt(root
, ENOSPC_DEBUG
))
883 seq_puts(seq
, ",enospc_debug");
884 if (btrfs_test_opt(root
, AUTO_DEFRAG
))
885 seq_puts(seq
, ",autodefrag");
886 if (btrfs_test_opt(root
, INODE_MAP_CACHE
))
887 seq_puts(seq
, ",inode_cache");
888 if (btrfs_test_opt(root
, SKIP_BALANCE
))
889 seq_puts(seq
, ",skip_balance");
890 if (btrfs_test_opt(root
, PANIC_ON_FATAL_ERROR
))
891 seq_puts(seq
, ",fatal_errors=panic");
895 static int btrfs_test_super(struct super_block
*s
, void *data
)
897 struct btrfs_fs_info
*p
= data
;
898 struct btrfs_fs_info
*fs_info
= btrfs_sb(s
);
900 return fs_info
->fs_devices
== p
->fs_devices
;
903 static int btrfs_set_super(struct super_block
*s
, void *data
)
905 int err
= set_anon_super(s
, data
);
912 * subvolumes are identified by ino 256
914 static inline int is_subvolume_inode(struct inode
*inode
)
916 if (inode
&& inode
->i_ino
== BTRFS_FIRST_FREE_OBJECTID
)
922 * This will strip out the subvol=%s argument for an argument string and add
923 * subvolid=0 to make sure we get the actual tree root for path walking to the
926 static char *setup_root_args(char *args
)
929 unsigned len
= strlen(args
) + 2;
934 * We need the same args as before, but minus
942 * which is a difference of 2 characters, so we allocate strlen(args) +
945 ret
= kzalloc(len
* sizeof(char), GFP_NOFS
);
948 pos
= strstr(args
, "subvol=");
950 /* This shouldn't happen, but just in case.. */
957 * The subvol=<> arg is not at the front of the string, copy everybody
958 * up to that into ret.
963 copied
+= strlen(args
);
967 strncpy(ret
+ copied
, "subvolid=0", len
- copied
);
969 /* Length of subvolid=0 */
973 * If there is no , after the subvol= option then we know there's no
974 * other options and we can just return.
976 pos
= strchr(pos
, ',');
980 /* Copy the rest of the arguments into our buffer */
981 strncpy(ret
+ copied
, pos
, len
- copied
);
982 copied
+= strlen(pos
);
987 static struct dentry
*mount_subvol(const char *subvol_name
, int flags
,
988 const char *device_name
, char *data
)
991 struct vfsmount
*mnt
;
994 newargs
= setup_root_args(data
);
996 return ERR_PTR(-ENOMEM
);
997 mnt
= vfs_kern_mount(&btrfs_fs_type
, flags
, device_name
,
1001 return ERR_CAST(mnt
);
1003 root
= mount_subtree(mnt
, subvol_name
);
1005 if (!IS_ERR(root
) && !is_subvolume_inode(root
->d_inode
)) {
1006 struct super_block
*s
= root
->d_sb
;
1008 root
= ERR_PTR(-EINVAL
);
1009 deactivate_locked_super(s
);
1010 printk(KERN_ERR
"btrfs: '%s' is not a valid subvolume\n",
1018 * Find a superblock for the given device / mount point.
1020 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1021 * for multiple device setup. Make sure to keep it in sync.
1023 static struct dentry
*btrfs_mount(struct file_system_type
*fs_type
, int flags
,
1024 const char *device_name
, void *data
)
1026 struct block_device
*bdev
= NULL
;
1027 struct super_block
*s
;
1028 struct dentry
*root
;
1029 struct btrfs_fs_devices
*fs_devices
= NULL
;
1030 struct btrfs_fs_info
*fs_info
= NULL
;
1031 fmode_t mode
= FMODE_READ
;
1032 char *subvol_name
= NULL
;
1033 u64 subvol_objectid
= 0;
1034 u64 subvol_rootid
= 0;
1037 if (!(flags
& MS_RDONLY
))
1038 mode
|= FMODE_WRITE
;
1040 error
= btrfs_parse_early_options(data
, mode
, fs_type
,
1041 &subvol_name
, &subvol_objectid
,
1042 &subvol_rootid
, &fs_devices
);
1045 return ERR_PTR(error
);
1049 root
= mount_subvol(subvol_name
, flags
, device_name
, data
);
1054 error
= btrfs_scan_one_device(device_name
, mode
, fs_type
, &fs_devices
);
1056 return ERR_PTR(error
);
1059 * Setup a dummy root and fs_info for test/set super. This is because
1060 * we don't actually fill this stuff out until open_ctree, but we need
1061 * it for searching for existing supers, so this lets us do that and
1062 * then open_ctree will properly initialize everything later.
1064 fs_info
= kzalloc(sizeof(struct btrfs_fs_info
), GFP_NOFS
);
1066 return ERR_PTR(-ENOMEM
);
1068 fs_info
->fs_devices
= fs_devices
;
1070 fs_info
->super_copy
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1071 fs_info
->super_for_commit
= kzalloc(BTRFS_SUPER_INFO_SIZE
, GFP_NOFS
);
1072 if (!fs_info
->super_copy
|| !fs_info
->super_for_commit
) {
1077 error
= btrfs_open_devices(fs_devices
, mode
, fs_type
);
1081 if (!(flags
& MS_RDONLY
) && fs_devices
->rw_devices
== 0) {
1083 goto error_close_devices
;
1086 bdev
= fs_devices
->latest_bdev
;
1087 s
= sget(fs_type
, btrfs_test_super
, btrfs_set_super
, fs_info
);
1090 goto error_close_devices
;
1094 btrfs_close_devices(fs_devices
);
1095 free_fs_info(fs_info
);
1096 if ((flags
^ s
->s_flags
) & MS_RDONLY
)
1099 char b
[BDEVNAME_SIZE
];
1101 s
->s_flags
= flags
| MS_NOSEC
;
1102 strlcpy(s
->s_id
, bdevname(bdev
, b
), sizeof(s
->s_id
));
1103 btrfs_sb(s
)->bdev_holder
= fs_type
;
1104 error
= btrfs_fill_super(s
, fs_devices
, data
,
1105 flags
& MS_SILENT
? 1 : 0);
1108 root
= !error
? get_default_root(s
, subvol_objectid
) : ERR_PTR(error
);
1110 deactivate_locked_super(s
);
1114 error_close_devices
:
1115 btrfs_close_devices(fs_devices
);
1117 free_fs_info(fs_info
);
1118 return ERR_PTR(error
);
1121 static int btrfs_remount(struct super_block
*sb
, int *flags
, char *data
)
1123 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1124 struct btrfs_root
*root
= fs_info
->tree_root
;
1125 unsigned old_flags
= sb
->s_flags
;
1126 unsigned long old_opts
= fs_info
->mount_opt
;
1127 unsigned long old_compress_type
= fs_info
->compress_type
;
1128 u64 old_max_inline
= fs_info
->max_inline
;
1129 u64 old_alloc_start
= fs_info
->alloc_start
;
1130 int old_thread_pool_size
= fs_info
->thread_pool_size
;
1131 unsigned int old_metadata_ratio
= fs_info
->metadata_ratio
;
1134 ret
= btrfs_parse_options(root
, data
);
1140 if ((*flags
& MS_RDONLY
) == (sb
->s_flags
& MS_RDONLY
))
1143 if (*flags
& MS_RDONLY
) {
1144 sb
->s_flags
|= MS_RDONLY
;
1146 ret
= btrfs_commit_super(root
);
1150 if (fs_info
->fs_devices
->rw_devices
== 0) {
1155 if (btrfs_super_log_root(fs_info
->super_copy
) != 0) {
1160 ret
= btrfs_cleanup_fs_roots(fs_info
);
1164 /* recover relocation */
1165 ret
= btrfs_recover_relocation(root
);
1169 sb
->s_flags
&= ~MS_RDONLY
;
1175 /* We've hit an error - don't reset MS_RDONLY */
1176 if (sb
->s_flags
& MS_RDONLY
)
1177 old_flags
|= MS_RDONLY
;
1178 sb
->s_flags
= old_flags
;
1179 fs_info
->mount_opt
= old_opts
;
1180 fs_info
->compress_type
= old_compress_type
;
1181 fs_info
->max_inline
= old_max_inline
;
1182 fs_info
->alloc_start
= old_alloc_start
;
1183 fs_info
->thread_pool_size
= old_thread_pool_size
;
1184 fs_info
->metadata_ratio
= old_metadata_ratio
;
1188 /* Used to sort the devices by max_avail(descending sort) */
1189 static int btrfs_cmp_device_free_bytes(const void *dev_info1
,
1190 const void *dev_info2
)
1192 if (((struct btrfs_device_info
*)dev_info1
)->max_avail
>
1193 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1195 else if (((struct btrfs_device_info
*)dev_info1
)->max_avail
<
1196 ((struct btrfs_device_info
*)dev_info2
)->max_avail
)
1203 * sort the devices by max_avail, in which max free extent size of each device
1204 * is stored.(Descending Sort)
1206 static inline void btrfs_descending_sort_devices(
1207 struct btrfs_device_info
*devices
,
1210 sort(devices
, nr_devices
, sizeof(struct btrfs_device_info
),
1211 btrfs_cmp_device_free_bytes
, NULL
);
1215 * The helper to calc the free space on the devices that can be used to store
1218 static int btrfs_calc_avail_data_space(struct btrfs_root
*root
, u64
*free_bytes
)
1220 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1221 struct btrfs_device_info
*devices_info
;
1222 struct btrfs_fs_devices
*fs_devices
= fs_info
->fs_devices
;
1223 struct btrfs_device
*device
;
1228 u64 min_stripe_size
;
1229 int min_stripes
= 1, num_stripes
= 1;
1230 int i
= 0, nr_devices
;
1233 nr_devices
= fs_info
->fs_devices
->open_devices
;
1234 BUG_ON(!nr_devices
);
1236 devices_info
= kmalloc(sizeof(*devices_info
) * nr_devices
,
1241 /* calc min stripe number for data space alloction */
1242 type
= btrfs_get_alloc_profile(root
, 1);
1243 if (type
& BTRFS_BLOCK_GROUP_RAID0
) {
1245 num_stripes
= nr_devices
;
1246 } else if (type
& BTRFS_BLOCK_GROUP_RAID1
) {
1249 } else if (type
& BTRFS_BLOCK_GROUP_RAID10
) {
1254 if (type
& BTRFS_BLOCK_GROUP_DUP
)
1255 min_stripe_size
= 2 * BTRFS_STRIPE_LEN
;
1257 min_stripe_size
= BTRFS_STRIPE_LEN
;
1259 list_for_each_entry(device
, &fs_devices
->devices
, dev_list
) {
1260 if (!device
->in_fs_metadata
|| !device
->bdev
)
1263 avail_space
= device
->total_bytes
- device
->bytes_used
;
1265 /* align with stripe_len */
1266 do_div(avail_space
, BTRFS_STRIPE_LEN
);
1267 avail_space
*= BTRFS_STRIPE_LEN
;
1270 * In order to avoid overwritting the superblock on the drive,
1271 * btrfs starts at an offset of at least 1MB when doing chunk
1274 skip_space
= 1024 * 1024;
1276 /* user can set the offset in fs_info->alloc_start. */
1277 if (fs_info
->alloc_start
+ BTRFS_STRIPE_LEN
<=
1278 device
->total_bytes
)
1279 skip_space
= max(fs_info
->alloc_start
, skip_space
);
1282 * btrfs can not use the free space in [0, skip_space - 1],
1283 * we must subtract it from the total. In order to implement
1284 * it, we account the used space in this range first.
1286 ret
= btrfs_account_dev_extents_size(device
, 0, skip_space
- 1,
1289 kfree(devices_info
);
1293 /* calc the free space in [0, skip_space - 1] */
1294 skip_space
-= used_space
;
1297 * we can use the free space in [0, skip_space - 1], subtract
1298 * it from the total.
1300 if (avail_space
&& avail_space
>= skip_space
)
1301 avail_space
-= skip_space
;
1305 if (avail_space
< min_stripe_size
)
1308 devices_info
[i
].dev
= device
;
1309 devices_info
[i
].max_avail
= avail_space
;
1316 btrfs_descending_sort_devices(devices_info
, nr_devices
);
1320 while (nr_devices
>= min_stripes
) {
1321 if (num_stripes
> nr_devices
)
1322 num_stripes
= nr_devices
;
1324 if (devices_info
[i
].max_avail
>= min_stripe_size
) {
1328 avail_space
+= devices_info
[i
].max_avail
* num_stripes
;
1329 alloc_size
= devices_info
[i
].max_avail
;
1330 for (j
= i
+ 1 - num_stripes
; j
<= i
; j
++)
1331 devices_info
[j
].max_avail
-= alloc_size
;
1337 kfree(devices_info
);
1338 *free_bytes
= avail_space
;
1342 static int btrfs_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
1344 struct btrfs_fs_info
*fs_info
= btrfs_sb(dentry
->d_sb
);
1345 struct btrfs_super_block
*disk_super
= fs_info
->super_copy
;
1346 struct list_head
*head
= &fs_info
->space_info
;
1347 struct btrfs_space_info
*found
;
1349 u64 total_free_data
= 0;
1350 int bits
= dentry
->d_sb
->s_blocksize_bits
;
1351 __be32
*fsid
= (__be32
*)fs_info
->fsid
;
1354 /* holding chunk_muext to avoid allocating new chunks */
1355 mutex_lock(&fs_info
->chunk_mutex
);
1357 list_for_each_entry_rcu(found
, head
, list
) {
1358 if (found
->flags
& BTRFS_BLOCK_GROUP_DATA
) {
1359 total_free_data
+= found
->disk_total
- found
->disk_used
;
1361 btrfs_account_ro_block_groups_free_space(found
);
1364 total_used
+= found
->disk_used
;
1368 buf
->f_namelen
= BTRFS_NAME_LEN
;
1369 buf
->f_blocks
= btrfs_super_total_bytes(disk_super
) >> bits
;
1370 buf
->f_bfree
= buf
->f_blocks
- (total_used
>> bits
);
1371 buf
->f_bsize
= dentry
->d_sb
->s_blocksize
;
1372 buf
->f_type
= BTRFS_SUPER_MAGIC
;
1373 buf
->f_bavail
= total_free_data
;
1374 ret
= btrfs_calc_avail_data_space(fs_info
->tree_root
, &total_free_data
);
1376 mutex_unlock(&fs_info
->chunk_mutex
);
1379 buf
->f_bavail
+= total_free_data
;
1380 buf
->f_bavail
= buf
->f_bavail
>> bits
;
1381 mutex_unlock(&fs_info
->chunk_mutex
);
1383 /* We treat it as constant endianness (it doesn't matter _which_)
1384 because we want the fsid to come out the same whether mounted
1385 on a big-endian or little-endian host */
1386 buf
->f_fsid
.val
[0] = be32_to_cpu(fsid
[0]) ^ be32_to_cpu(fsid
[2]);
1387 buf
->f_fsid
.val
[1] = be32_to_cpu(fsid
[1]) ^ be32_to_cpu(fsid
[3]);
1388 /* Mask in the root object ID too, to disambiguate subvols */
1389 buf
->f_fsid
.val
[0] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
>> 32;
1390 buf
->f_fsid
.val
[1] ^= BTRFS_I(dentry
->d_inode
)->root
->objectid
;
1395 static void btrfs_kill_super(struct super_block
*sb
)
1397 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1398 kill_anon_super(sb
);
1399 free_fs_info(fs_info
);
1402 static struct file_system_type btrfs_fs_type
= {
1403 .owner
= THIS_MODULE
,
1405 .mount
= btrfs_mount
,
1406 .kill_sb
= btrfs_kill_super
,
1407 .fs_flags
= FS_REQUIRES_DEV
,
1411 * used by btrfsctl to scan devices when no FS is mounted
1413 static long btrfs_control_ioctl(struct file
*file
, unsigned int cmd
,
1416 struct btrfs_ioctl_vol_args
*vol
;
1417 struct btrfs_fs_devices
*fs_devices
;
1420 if (!capable(CAP_SYS_ADMIN
))
1423 vol
= memdup_user((void __user
*)arg
, sizeof(*vol
));
1425 return PTR_ERR(vol
);
1428 case BTRFS_IOC_SCAN_DEV
:
1429 ret
= btrfs_scan_one_device(vol
->name
, FMODE_READ
,
1430 &btrfs_fs_type
, &fs_devices
);
1438 static int btrfs_freeze(struct super_block
*sb
)
1440 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1441 mutex_lock(&fs_info
->transaction_kthread_mutex
);
1442 mutex_lock(&fs_info
->cleaner_mutex
);
1446 static int btrfs_unfreeze(struct super_block
*sb
)
1448 struct btrfs_fs_info
*fs_info
= btrfs_sb(sb
);
1449 mutex_unlock(&fs_info
->cleaner_mutex
);
1450 mutex_unlock(&fs_info
->transaction_kthread_mutex
);
1454 static void btrfs_fs_dirty_inode(struct inode
*inode
, int flags
)
1458 ret
= btrfs_dirty_inode(inode
);
1460 printk_ratelimited(KERN_ERR
"btrfs: fail to dirty inode %Lu "
1461 "error %d\n", btrfs_ino(inode
), ret
);
1464 static const struct super_operations btrfs_super_ops
= {
1465 .drop_inode
= btrfs_drop_inode
,
1466 .evict_inode
= btrfs_evict_inode
,
1467 .put_super
= btrfs_put_super
,
1468 .sync_fs
= btrfs_sync_fs
,
1469 .show_options
= btrfs_show_options
,
1470 .write_inode
= btrfs_write_inode
,
1471 .dirty_inode
= btrfs_fs_dirty_inode
,
1472 .alloc_inode
= btrfs_alloc_inode
,
1473 .destroy_inode
= btrfs_destroy_inode
,
1474 .statfs
= btrfs_statfs
,
1475 .remount_fs
= btrfs_remount
,
1476 .freeze_fs
= btrfs_freeze
,
1477 .unfreeze_fs
= btrfs_unfreeze
,
1480 static const struct file_operations btrfs_ctl_fops
= {
1481 .unlocked_ioctl
= btrfs_control_ioctl
,
1482 .compat_ioctl
= btrfs_control_ioctl
,
1483 .owner
= THIS_MODULE
,
1484 .llseek
= noop_llseek
,
1487 static struct miscdevice btrfs_misc
= {
1488 .minor
= BTRFS_MINOR
,
1489 .name
= "btrfs-control",
1490 .fops
= &btrfs_ctl_fops
1493 MODULE_ALIAS_MISCDEV(BTRFS_MINOR
);
1494 MODULE_ALIAS("devname:btrfs-control");
1496 static int btrfs_interface_init(void)
1498 return misc_register(&btrfs_misc
);
1501 static void btrfs_interface_exit(void)
1503 if (misc_deregister(&btrfs_misc
) < 0)
1504 printk(KERN_INFO
"misc_deregister failed for control device");
1507 static int __init
init_btrfs_fs(void)
1511 err
= btrfs_init_sysfs();
1515 btrfs_init_compress();
1517 err
= btrfs_init_cachep();
1521 err
= extent_io_init();
1525 err
= extent_map_init();
1527 goto free_extent_io
;
1529 err
= btrfs_delayed_inode_init();
1531 goto free_extent_map
;
1533 err
= btrfs_interface_init();
1535 goto free_delayed_inode
;
1537 err
= register_filesystem(&btrfs_fs_type
);
1539 goto unregister_ioctl
;
1541 btrfs_init_lockdep();
1543 printk(KERN_INFO
"%s loaded\n", BTRFS_BUILD_VERSION
);
1547 btrfs_interface_exit();
1549 btrfs_delayed_inode_exit();
1555 btrfs_destroy_cachep();
1557 btrfs_exit_compress();
1562 static void __exit
exit_btrfs_fs(void)
1564 btrfs_destroy_cachep();
1565 btrfs_delayed_inode_exit();
1568 btrfs_interface_exit();
1569 unregister_filesystem(&btrfs_fs_type
);
1571 btrfs_cleanup_fs_uuids();
1572 btrfs_exit_compress();
1575 module_init(init_btrfs_fs
)
1576 module_exit(exit_btrfs_fs
)
1578 MODULE_LICENSE("GPL");