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>
44 #include <linux/btrfs.h>
46 #include "delayed-inode.h"
49 #include "transaction.h"
50 #include "btrfs_inode.h"
51 #include "print-tree.h"
55 #include "compression.h"
56 #include "rcu-string.h"
57 #include "dev-replace.h"
58 #include "free-space-cache.h"
60 #define CREATE_TRACE_POINTS
61 #include <trace/events/btrfs.h>
63 static const struct super_operations btrfs_super_ops;
64 static struct file_system_type btrfs_fs_type;
66 static const char *btrfs_decode_error(int errno)
68 char *errstr = "unknown";
72 errstr = "IO failure";
75 errstr = "Out of memory";
78 errstr = "Readonly filesystem";
81 errstr = "Object already exists";
84 errstr = "No space left";
87 errstr = "No such entry";
94 static void save_error_info(struct btrfs_fs_info *fs_info)
97 * today we only save the error info into ram. Long term we'll
98 * also send it down to the disk
100 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
103 /* btrfs handle error by forcing the filesystem readonly */
104 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
106 struct super_block *sb = fs_info->sb;
108 if (sb->s_flags & MS_RDONLY)
111 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
112 sb->s_flags |= MS_RDONLY;
113 btrfs_info(fs_info, "forced readonly");
115 * Note that a running device replace operation is not
116 * canceled here although there is no way to update
117 * the progress. It would add the risk of a deadlock,
118 * therefore the canceling is ommited. The only penalty
119 * is that some I/O remains active until the procedure
120 * completes. The next time when the filesystem is
121 * mounted writeable again, the device replace
122 * operation continues.
129 * __btrfs_std_error decodes expected errors from the caller and
130 * invokes the approciate error response.
132 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
133 unsigned int line, int errno, const char *fmt, ...)
135 struct super_block *sb = fs_info->sb;
139 * Special case: if the error is EROFS, and we're already
140 * under MS_RDONLY, then it is safe here.
142 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
145 errstr = btrfs_decode_error(errno);
147 struct va_format vaf;
154 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s (%pV)\n",
155 sb->s_id, function, line, errno, errstr, &vaf);
158 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s\n",
159 sb->s_id, function, line, errno, errstr);
162 /* Don't go through full error handling during mount */
163 save_error_info(fs_info);
164 if (sb->s_flags & MS_BORN)
165 btrfs_handle_error(fs_info);
168 static const char * const logtypes[] = {
179 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
181 struct super_block *sb = fs_info->sb;
183 struct va_format vaf;
185 const char *type = logtypes[4];
190 kern_level = printk_get_level(fmt);
192 size_t size = printk_skip_level(fmt) - fmt;
193 memcpy(lvl, fmt, size);
196 type = logtypes[kern_level - '0'];
203 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
210 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
211 unsigned int line, int errno, const char *fmt, ...)
213 struct super_block *sb = fs_info->sb;
216 * Special case: if the error is EROFS, and we're already
217 * under MS_RDONLY, then it is safe here.
219 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
222 /* Don't go through full error handling during mount */
223 if (sb->s_flags & MS_BORN) {
224 save_error_info(fs_info);
225 btrfs_handle_error(fs_info);
231 * We only mark the transaction aborted and then set the file system read-only.
232 * This will prevent new transactions from starting or trying to join this
235 * This means that error recovery at the call site is limited to freeing
236 * any local memory allocations and passing the error code up without
237 * further cleanup. The transaction should complete as it normally would
238 * in the call path but will return -EIO.
240 * We'll complete the cleanup in btrfs_end_transaction and
241 * btrfs_commit_transaction.
243 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
244 struct btrfs_root *root, const char *function,
245 unsigned int line, int errno)
248 * Report first abort since mount
250 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
251 &root->fs_info->fs_state)) {
252 WARN(1, KERN_DEBUG "btrfs: Transaction aborted (error %d)\n",
255 trans->aborted = errno;
256 /* Nothing used. The other threads that have joined this
257 * transaction may be able to continue. */
258 if (!trans->blocks_used) {
261 errstr = btrfs_decode_error(errno);
262 btrfs_warn(root->fs_info,
263 "%s:%d: Aborting unused transaction(%s).",
264 function, line, errstr);
267 ACCESS_ONCE(trans->transaction->aborted) = errno;
268 /* Wake up anybody who may be waiting on this transaction */
269 wake_up(&root->fs_info->transaction_wait);
270 wake_up(&root->fs_info->transaction_blocked_wait);
271 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
274 * __btrfs_panic decodes unexpected, fatal errors from the caller,
275 * issues an alert, and either panics or BUGs, depending on mount options.
277 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
278 unsigned int line, int errno, const char *fmt, ...)
280 char *s_id = "<unknown>";
282 struct va_format vaf = { .fmt = fmt };
286 s_id = fs_info->sb->s_id;
291 errstr = btrfs_decode_error(errno);
292 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
293 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
294 s_id, function, line, &vaf, errno, errstr);
296 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
297 s_id, function, line, &vaf, errno, errstr);
299 /* Caller calls BUG() */
302 static void btrfs_put_super(struct super_block *sb)
304 (void)close_ctree(btrfs_sb(sb)->tree_root);
305 /* FIXME: need to fix VFS to return error? */
306 /* AV: return it _where_? ->put_super() can be triggered by any number
307 * of async events, up to and including delivery of SIGKILL to the
308 * last process that kept it busy. Or segfault in the aforementioned
309 * process... Whom would you report that to?
314 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
315 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
316 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
317 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
318 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
319 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
320 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
321 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
322 Opt_check_integrity, Opt_check_integrity_including_extent_data,
323 Opt_check_integrity_print_mask, Opt_fatal_errors,
327 static match_table_t tokens = {
328 {Opt_degraded, "degraded"},
329 {Opt_subvol, "subvol=%s"},
330 {Opt_subvolid, "subvolid=%d"},
331 {Opt_device, "device=%s"},
332 {Opt_nodatasum, "nodatasum"},
333 {Opt_nodatacow, "nodatacow"},
334 {Opt_nobarrier, "nobarrier"},
335 {Opt_max_inline, "max_inline=%s"},
336 {Opt_alloc_start, "alloc_start=%s"},
337 {Opt_thread_pool, "thread_pool=%d"},
338 {Opt_compress, "compress"},
339 {Opt_compress_type, "compress=%s"},
340 {Opt_compress_force, "compress-force"},
341 {Opt_compress_force_type, "compress-force=%s"},
343 {Opt_ssd_spread, "ssd_spread"},
344 {Opt_nossd, "nossd"},
345 {Opt_noacl, "noacl"},
346 {Opt_notreelog, "notreelog"},
347 {Opt_flushoncommit, "flushoncommit"},
348 {Opt_ratio, "metadata_ratio=%d"},
349 {Opt_discard, "discard"},
350 {Opt_space_cache, "space_cache"},
351 {Opt_clear_cache, "clear_cache"},
352 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
353 {Opt_enospc_debug, "enospc_debug"},
354 {Opt_subvolrootid, "subvolrootid=%d"},
355 {Opt_defrag, "autodefrag"},
356 {Opt_inode_cache, "inode_cache"},
357 {Opt_no_space_cache, "nospace_cache"},
358 {Opt_recovery, "recovery"},
359 {Opt_skip_balance, "skip_balance"},
360 {Opt_check_integrity, "check_int"},
361 {Opt_check_integrity_including_extent_data, "check_int_data"},
362 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
363 {Opt_fatal_errors, "fatal_errors=%s"},
368 * Regular mount options parser. Everything that is needed only when
369 * reading in a new superblock is parsed here.
370 * XXX JDM: This needs to be cleaned up for remount.
372 int btrfs_parse_options(struct btrfs_root *root, char *options)
374 struct btrfs_fs_info *info = root->fs_info;
375 substring_t args[MAX_OPT_ARGS];
376 char *p, *num, *orig = NULL;
381 bool compress_force = false;
383 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
385 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
391 * strsep changes the string, duplicate it because parse_options
394 options = kstrdup(options, GFP_NOFS);
400 while ((p = strsep(&options, ",")) != NULL) {
405 token = match_token(p, tokens, args);
408 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
409 btrfs_set_opt(info->mount_opt, DEGRADED);
413 case Opt_subvolrootid:
416 * These are parsed by btrfs_parse_early_options
417 * and can be happily ignored here.
421 printk(KERN_INFO "btrfs: setting nodatasum\n");
422 btrfs_set_opt(info->mount_opt, NODATASUM);
425 if (!btrfs_test_opt(root, COMPRESS) ||
426 !btrfs_test_opt(root, FORCE_COMPRESS)) {
427 printk(KERN_INFO "btrfs: setting nodatacow, compression disabled\n");
429 printk(KERN_INFO "btrfs: setting nodatacow\n");
431 info->compress_type = BTRFS_COMPRESS_NONE;
432 btrfs_clear_opt(info->mount_opt, COMPRESS);
433 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
434 btrfs_set_opt(info->mount_opt, NODATACOW);
435 btrfs_set_opt(info->mount_opt, NODATASUM);
437 case Opt_compress_force:
438 case Opt_compress_force_type:
439 compress_force = true;
442 case Opt_compress_type:
443 if (token == Opt_compress ||
444 token == Opt_compress_force ||
445 strcmp(args[0].from, "zlib") == 0) {
446 compress_type = "zlib";
447 info->compress_type = BTRFS_COMPRESS_ZLIB;
448 btrfs_set_opt(info->mount_opt, COMPRESS);
449 btrfs_clear_opt(info->mount_opt, NODATACOW);
450 btrfs_clear_opt(info->mount_opt, NODATASUM);
451 } else if (strcmp(args[0].from, "lzo") == 0) {
452 compress_type = "lzo";
453 info->compress_type = BTRFS_COMPRESS_LZO;
454 btrfs_set_opt(info->mount_opt, COMPRESS);
455 btrfs_clear_opt(info->mount_opt, NODATACOW);
456 btrfs_clear_opt(info->mount_opt, NODATASUM);
457 btrfs_set_fs_incompat(info, COMPRESS_LZO);
458 } else if (strncmp(args[0].from, "no", 2) == 0) {
459 compress_type = "no";
460 info->compress_type = BTRFS_COMPRESS_NONE;
461 btrfs_clear_opt(info->mount_opt, COMPRESS);
462 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
463 compress_force = false;
469 if (compress_force) {
470 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
471 pr_info("btrfs: force %s compression\n",
474 pr_info("btrfs: use %s compression\n",
478 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
479 btrfs_set_opt(info->mount_opt, SSD);
482 printk(KERN_INFO "btrfs: use spread ssd "
483 "allocation scheme\n");
484 btrfs_set_opt(info->mount_opt, SSD);
485 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
488 printk(KERN_INFO "btrfs: not using ssd allocation "
490 btrfs_set_opt(info->mount_opt, NOSSD);
491 btrfs_clear_opt(info->mount_opt, SSD);
492 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
495 printk(KERN_INFO "btrfs: turning off barriers\n");
496 btrfs_set_opt(info->mount_opt, NOBARRIER);
498 case Opt_thread_pool:
500 match_int(&args[0], &intarg);
502 info->thread_pool_size = intarg;
505 num = match_strdup(&args[0]);
507 info->max_inline = memparse(num, NULL);
510 if (info->max_inline) {
511 info->max_inline = max_t(u64,
515 printk(KERN_INFO "btrfs: max_inline at %llu\n",
516 (unsigned long long)info->max_inline);
519 case Opt_alloc_start:
520 num = match_strdup(&args[0]);
522 mutex_lock(&info->chunk_mutex);
523 info->alloc_start = memparse(num, NULL);
524 mutex_unlock(&info->chunk_mutex);
527 "btrfs: allocations start at %llu\n",
528 (unsigned long long)info->alloc_start);
532 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
535 printk(KERN_INFO "btrfs: disabling tree log\n");
536 btrfs_set_opt(info->mount_opt, NOTREELOG);
538 case Opt_flushoncommit:
539 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
540 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
544 match_int(&args[0], &intarg);
546 info->metadata_ratio = intarg;
547 printk(KERN_INFO "btrfs: metadata ratio %d\n",
548 info->metadata_ratio);
552 btrfs_set_opt(info->mount_opt, DISCARD);
554 case Opt_space_cache:
555 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
557 case Opt_no_space_cache:
558 printk(KERN_INFO "btrfs: disabling disk space caching\n");
559 btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
561 case Opt_inode_cache:
562 printk(KERN_INFO "btrfs: enabling inode map caching\n");
563 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
565 case Opt_clear_cache:
566 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
567 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
569 case Opt_user_subvol_rm_allowed:
570 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
572 case Opt_enospc_debug:
573 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
576 printk(KERN_INFO "btrfs: enabling auto defrag\n");
577 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
580 printk(KERN_INFO "btrfs: enabling auto recovery\n");
581 btrfs_set_opt(info->mount_opt, RECOVERY);
583 case Opt_skip_balance:
584 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
586 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
587 case Opt_check_integrity_including_extent_data:
588 printk(KERN_INFO "btrfs: enabling check integrity"
589 " including extent data\n");
590 btrfs_set_opt(info->mount_opt,
591 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
592 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
594 case Opt_check_integrity:
595 printk(KERN_INFO "btrfs: enabling check integrity\n");
596 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
598 case Opt_check_integrity_print_mask:
600 match_int(&args[0], &intarg);
602 info->check_integrity_print_mask = intarg;
603 printk(KERN_INFO "btrfs:"
604 " check_integrity_print_mask 0x%x\n",
605 info->check_integrity_print_mask);
609 case Opt_check_integrity_including_extent_data:
610 case Opt_check_integrity:
611 case Opt_check_integrity_print_mask:
612 printk(KERN_ERR "btrfs: support for check_integrity*"
613 " not compiled in!\n");
617 case Opt_fatal_errors:
618 if (strcmp(args[0].from, "panic") == 0)
619 btrfs_set_opt(info->mount_opt,
620 PANIC_ON_FATAL_ERROR);
621 else if (strcmp(args[0].from, "bug") == 0)
622 btrfs_clear_opt(info->mount_opt,
623 PANIC_ON_FATAL_ERROR);
630 printk(KERN_INFO "btrfs: unrecognized mount option "
639 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
640 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
646 * Parse mount options that are required early in the mount process.
648 * All other options will be parsed on much later in the mount process and
649 * only when we need to allocate a new super block.
651 static int btrfs_parse_early_options(const char *options, fmode_t flags,
652 void *holder, char **subvol_name, u64 *subvol_objectid,
653 struct btrfs_fs_devices **fs_devices)
655 substring_t args[MAX_OPT_ARGS];
656 char *device_name, *opts, *orig, *p;
664 * strsep changes the string, duplicate it because parse_options
667 opts = kstrdup(options, GFP_KERNEL);
672 while ((p = strsep(&opts, ",")) != NULL) {
677 token = match_token(p, tokens, args);
681 *subvol_name = match_strdup(&args[0]);
685 error = match_int(&args[0], &intarg);
687 /* we want the original fs_tree */
690 BTRFS_FS_TREE_OBJECTID;
692 *subvol_objectid = intarg;
695 case Opt_subvolrootid:
697 "btrfs: 'subvolrootid' mount option is deprecated and has no effect\n");
700 device_name = match_strdup(&args[0]);
705 error = btrfs_scan_one_device(device_name,
706 flags, holder, fs_devices);
721 static struct dentry *get_default_root(struct super_block *sb,
724 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
725 struct btrfs_root *root = fs_info->tree_root;
726 struct btrfs_root *new_root;
727 struct btrfs_dir_item *di;
728 struct btrfs_path *path;
729 struct btrfs_key location;
735 * We have a specific subvol we want to mount, just setup location and
736 * go look up the root.
738 if (subvol_objectid) {
739 location.objectid = subvol_objectid;
740 location.type = BTRFS_ROOT_ITEM_KEY;
741 location.offset = (u64)-1;
745 path = btrfs_alloc_path();
747 return ERR_PTR(-ENOMEM);
748 path->leave_spinning = 1;
751 * Find the "default" dir item which points to the root item that we
752 * will mount by default if we haven't been given a specific subvolume
755 dir_id = btrfs_super_root_dir(fs_info->super_copy);
756 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
758 btrfs_free_path(path);
763 * Ok the default dir item isn't there. This is weird since
764 * it's always been there, but don't freak out, just try and
765 * mount to root most subvolume.
767 btrfs_free_path(path);
768 dir_id = BTRFS_FIRST_FREE_OBJECTID;
769 new_root = fs_info->fs_root;
773 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
774 btrfs_free_path(path);
777 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
778 if (IS_ERR(new_root))
779 return ERR_CAST(new_root);
781 dir_id = btrfs_root_dirid(&new_root->root_item);
783 location.objectid = dir_id;
784 location.type = BTRFS_INODE_ITEM_KEY;
787 inode = btrfs_iget(sb, &location, new_root, &new);
789 return ERR_CAST(inode);
792 * If we're just mounting the root most subvol put the inode and return
793 * a reference to the dentry. We will have already gotten a reference
794 * to the inode in btrfs_fill_super so we're good to go.
796 if (!new && sb->s_root->d_inode == inode) {
798 return dget(sb->s_root);
801 return d_obtain_alias(inode);
804 static int btrfs_fill_super(struct super_block *sb,
805 struct btrfs_fs_devices *fs_devices,
806 void *data, int silent)
809 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
810 struct btrfs_key key;
813 sb->s_maxbytes = MAX_LFS_FILESIZE;
814 sb->s_magic = BTRFS_SUPER_MAGIC;
815 sb->s_op = &btrfs_super_ops;
816 sb->s_d_op = &btrfs_dentry_operations;
817 sb->s_export_op = &btrfs_export_ops;
818 sb->s_xattr = btrfs_xattr_handlers;
820 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
821 sb->s_flags |= MS_POSIXACL;
823 sb->s_flags |= MS_I_VERSION;
824 err = open_ctree(sb, fs_devices, (char *)data);
826 printk("btrfs: open_ctree failed\n");
830 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
831 key.type = BTRFS_INODE_ITEM_KEY;
833 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
835 err = PTR_ERR(inode);
839 sb->s_root = d_make_root(inode);
845 save_mount_options(sb, data);
846 cleancache_init_fs(sb);
847 sb->s_flags |= MS_ACTIVE;
851 close_ctree(fs_info->tree_root);
855 int btrfs_sync_fs(struct super_block *sb, int wait)
857 struct btrfs_trans_handle *trans;
858 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
859 struct btrfs_root *root = fs_info->tree_root;
861 trace_btrfs_sync_fs(wait);
864 filemap_flush(fs_info->btree_inode->i_mapping);
868 btrfs_wait_all_ordered_extents(fs_info, 1);
870 trans = btrfs_attach_transaction_barrier(root);
872 /* no transaction, don't bother */
873 if (PTR_ERR(trans) == -ENOENT)
875 return PTR_ERR(trans);
877 return btrfs_commit_transaction(trans, root);
880 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
882 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
883 struct btrfs_root *root = info->tree_root;
886 if (btrfs_test_opt(root, DEGRADED))
887 seq_puts(seq, ",degraded");
888 if (btrfs_test_opt(root, NODATASUM))
889 seq_puts(seq, ",nodatasum");
890 if (btrfs_test_opt(root, NODATACOW))
891 seq_puts(seq, ",nodatacow");
892 if (btrfs_test_opt(root, NOBARRIER))
893 seq_puts(seq, ",nobarrier");
894 if (info->max_inline != 8192 * 1024)
895 seq_printf(seq, ",max_inline=%llu",
896 (unsigned long long)info->max_inline);
897 if (info->alloc_start != 0)
898 seq_printf(seq, ",alloc_start=%llu",
899 (unsigned long long)info->alloc_start);
900 if (info->thread_pool_size != min_t(unsigned long,
901 num_online_cpus() + 2, 8))
902 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
903 if (btrfs_test_opt(root, COMPRESS)) {
904 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
905 compress_type = "zlib";
907 compress_type = "lzo";
908 if (btrfs_test_opt(root, FORCE_COMPRESS))
909 seq_printf(seq, ",compress-force=%s", compress_type);
911 seq_printf(seq, ",compress=%s", compress_type);
913 if (btrfs_test_opt(root, NOSSD))
914 seq_puts(seq, ",nossd");
915 if (btrfs_test_opt(root, SSD_SPREAD))
916 seq_puts(seq, ",ssd_spread");
917 else if (btrfs_test_opt(root, SSD))
918 seq_puts(seq, ",ssd");
919 if (btrfs_test_opt(root, NOTREELOG))
920 seq_puts(seq, ",notreelog");
921 if (btrfs_test_opt(root, FLUSHONCOMMIT))
922 seq_puts(seq, ",flushoncommit");
923 if (btrfs_test_opt(root, DISCARD))
924 seq_puts(seq, ",discard");
925 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
926 seq_puts(seq, ",noacl");
927 if (btrfs_test_opt(root, SPACE_CACHE))
928 seq_puts(seq, ",space_cache");
930 seq_puts(seq, ",nospace_cache");
931 if (btrfs_test_opt(root, CLEAR_CACHE))
932 seq_puts(seq, ",clear_cache");
933 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
934 seq_puts(seq, ",user_subvol_rm_allowed");
935 if (btrfs_test_opt(root, ENOSPC_DEBUG))
936 seq_puts(seq, ",enospc_debug");
937 if (btrfs_test_opt(root, AUTO_DEFRAG))
938 seq_puts(seq, ",autodefrag");
939 if (btrfs_test_opt(root, INODE_MAP_CACHE))
940 seq_puts(seq, ",inode_cache");
941 if (btrfs_test_opt(root, SKIP_BALANCE))
942 seq_puts(seq, ",skip_balance");
943 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
944 seq_puts(seq, ",fatal_errors=panic");
948 static int btrfs_test_super(struct super_block *s, void *data)
950 struct btrfs_fs_info *p = data;
951 struct btrfs_fs_info *fs_info = btrfs_sb(s);
953 return fs_info->fs_devices == p->fs_devices;
956 static int btrfs_set_super(struct super_block *s, void *data)
958 int err = set_anon_super(s, data);
965 * subvolumes are identified by ino 256
967 static inline int is_subvolume_inode(struct inode *inode)
969 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
975 * This will strip out the subvol=%s argument for an argument string and add
976 * subvolid=0 to make sure we get the actual tree root for path walking to the
979 static char *setup_root_args(char *args)
981 unsigned len = strlen(args) + 2 + 1;
982 char *src, *dst, *buf;
985 * We need the same args as before, but with this substitution:
986 * s!subvol=[^,]+!subvolid=0!
988 * Since the replacement string is up to 2 bytes longer than the
989 * original, allocate strlen(args) + 2 + 1 bytes.
992 src = strstr(args, "subvol=");
993 /* This shouldn't happen, but just in case.. */
997 buf = dst = kmalloc(len, GFP_NOFS);
1002 * If the subvol= arg is not at the start of the string,
1003 * copy whatever precedes it into buf.
1008 dst += strlen(args);
1011 strcpy(dst, "subvolid=0");
1012 dst += strlen("subvolid=0");
1015 * If there is a "," after the original subvol=... string,
1016 * copy that suffix into our buffer. Otherwise, we're done.
1018 src = strchr(src, ',');
1025 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1026 const char *device_name, char *data)
1028 struct dentry *root;
1029 struct vfsmount *mnt;
1032 newargs = setup_root_args(data);
1034 return ERR_PTR(-ENOMEM);
1035 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1039 return ERR_CAST(mnt);
1041 root = mount_subtree(mnt, subvol_name);
1043 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1044 struct super_block *s = root->d_sb;
1046 root = ERR_PTR(-EINVAL);
1047 deactivate_locked_super(s);
1048 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
1056 * Find a superblock for the given device / mount point.
1058 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1059 * for multiple device setup. Make sure to keep it in sync.
1061 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1062 const char *device_name, void *data)
1064 struct block_device *bdev = NULL;
1065 struct super_block *s;
1066 struct dentry *root;
1067 struct btrfs_fs_devices *fs_devices = NULL;
1068 struct btrfs_fs_info *fs_info = NULL;
1069 fmode_t mode = FMODE_READ;
1070 char *subvol_name = NULL;
1071 u64 subvol_objectid = 0;
1074 if (!(flags & MS_RDONLY))
1075 mode |= FMODE_WRITE;
1077 error = btrfs_parse_early_options(data, mode, fs_type,
1078 &subvol_name, &subvol_objectid,
1082 return ERR_PTR(error);
1086 root = mount_subvol(subvol_name, flags, device_name, data);
1091 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1093 return ERR_PTR(error);
1096 * Setup a dummy root and fs_info for test/set super. This is because
1097 * we don't actually fill this stuff out until open_ctree, but we need
1098 * it for searching for existing supers, so this lets us do that and
1099 * then open_ctree will properly initialize everything later.
1101 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1103 return ERR_PTR(-ENOMEM);
1105 fs_info->fs_devices = fs_devices;
1107 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1108 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1109 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1114 error = btrfs_open_devices(fs_devices, mode, fs_type);
1118 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1120 goto error_close_devices;
1123 bdev = fs_devices->latest_bdev;
1124 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1128 goto error_close_devices;
1132 btrfs_close_devices(fs_devices);
1133 free_fs_info(fs_info);
1134 if ((flags ^ s->s_flags) & MS_RDONLY)
1137 char b[BDEVNAME_SIZE];
1139 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1140 btrfs_sb(s)->bdev_holder = fs_type;
1141 error = btrfs_fill_super(s, fs_devices, data,
1142 flags & MS_SILENT ? 1 : 0);
1145 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1147 deactivate_locked_super(s);
1151 error_close_devices:
1152 btrfs_close_devices(fs_devices);
1154 free_fs_info(fs_info);
1155 return ERR_PTR(error);
1158 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1160 spin_lock_irq(&workers->lock);
1161 workers->max_workers = new_limit;
1162 spin_unlock_irq(&workers->lock);
1165 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1166 int new_pool_size, int old_pool_size)
1168 if (new_pool_size == old_pool_size)
1171 fs_info->thread_pool_size = new_pool_size;
1173 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1174 old_pool_size, new_pool_size);
1176 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1177 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1178 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1179 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1180 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1181 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1182 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1183 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1184 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1185 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1186 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1187 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1188 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1189 btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1193 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1195 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1198 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1199 unsigned long old_opts, int flags)
1201 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1202 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1203 (flags & MS_RDONLY))) {
1204 /* wait for any defraggers to finish */
1205 wait_event(fs_info->transaction_wait,
1206 (atomic_read(&fs_info->defrag_running) == 0));
1207 if (flags & MS_RDONLY)
1208 sync_filesystem(fs_info->sb);
1212 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1213 unsigned long old_opts)
1216 * We need cleanup all defragable inodes if the autodefragment is
1217 * close or the fs is R/O.
1219 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1220 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1221 (fs_info->sb->s_flags & MS_RDONLY))) {
1222 btrfs_cleanup_defrag_inodes(fs_info);
1225 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1228 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1230 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1231 struct btrfs_root *root = fs_info->tree_root;
1232 unsigned old_flags = sb->s_flags;
1233 unsigned long old_opts = fs_info->mount_opt;
1234 unsigned long old_compress_type = fs_info->compress_type;
1235 u64 old_max_inline = fs_info->max_inline;
1236 u64 old_alloc_start = fs_info->alloc_start;
1237 int old_thread_pool_size = fs_info->thread_pool_size;
1238 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1241 btrfs_remount_prepare(fs_info);
1243 ret = btrfs_parse_options(root, data);
1249 btrfs_remount_begin(fs_info, old_opts, *flags);
1250 btrfs_resize_thread_pool(fs_info,
1251 fs_info->thread_pool_size, old_thread_pool_size);
1253 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1256 if (*flags & MS_RDONLY) {
1258 * this also happens on 'umount -rf' or on shutdown, when
1259 * the filesystem is busy.
1261 sb->s_flags |= MS_RDONLY;
1263 btrfs_dev_replace_suspend_for_unmount(fs_info);
1264 btrfs_scrub_cancel(fs_info);
1265 btrfs_pause_balance(fs_info);
1267 ret = btrfs_commit_super(root);
1271 if (fs_info->fs_devices->rw_devices == 0) {
1276 if (fs_info->fs_devices->missing_devices >
1277 fs_info->num_tolerated_disk_barrier_failures &&
1278 !(*flags & MS_RDONLY)) {
1280 "Btrfs: too many missing devices, writeable remount is not allowed\n");
1285 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1290 ret = btrfs_cleanup_fs_roots(fs_info);
1294 /* recover relocation */
1295 ret = btrfs_recover_relocation(root);
1299 ret = btrfs_resume_balance_async(fs_info);
1303 ret = btrfs_resume_dev_replace_async(fs_info);
1305 pr_warn("btrfs: failed to resume dev_replace\n");
1308 sb->s_flags &= ~MS_RDONLY;
1311 btrfs_remount_cleanup(fs_info, old_opts);
1315 /* We've hit an error - don't reset MS_RDONLY */
1316 if (sb->s_flags & MS_RDONLY)
1317 old_flags |= MS_RDONLY;
1318 sb->s_flags = old_flags;
1319 fs_info->mount_opt = old_opts;
1320 fs_info->compress_type = old_compress_type;
1321 fs_info->max_inline = old_max_inline;
1322 mutex_lock(&fs_info->chunk_mutex);
1323 fs_info->alloc_start = old_alloc_start;
1324 mutex_unlock(&fs_info->chunk_mutex);
1325 btrfs_resize_thread_pool(fs_info,
1326 old_thread_pool_size, fs_info->thread_pool_size);
1327 fs_info->metadata_ratio = old_metadata_ratio;
1328 btrfs_remount_cleanup(fs_info, old_opts);
1332 /* Used to sort the devices by max_avail(descending sort) */
1333 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1334 const void *dev_info2)
1336 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1337 ((struct btrfs_device_info *)dev_info2)->max_avail)
1339 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1340 ((struct btrfs_device_info *)dev_info2)->max_avail)
1347 * sort the devices by max_avail, in which max free extent size of each device
1348 * is stored.(Descending Sort)
1350 static inline void btrfs_descending_sort_devices(
1351 struct btrfs_device_info *devices,
1354 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1355 btrfs_cmp_device_free_bytes, NULL);
1359 * The helper to calc the free space on the devices that can be used to store
1362 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1364 struct btrfs_fs_info *fs_info = root->fs_info;
1365 struct btrfs_device_info *devices_info;
1366 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1367 struct btrfs_device *device;
1372 u64 min_stripe_size;
1373 int min_stripes = 1, num_stripes = 1;
1374 int i = 0, nr_devices;
1377 nr_devices = fs_info->fs_devices->open_devices;
1378 BUG_ON(!nr_devices);
1380 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1385 /* calc min stripe number for data space alloction */
1386 type = btrfs_get_alloc_profile(root, 1);
1387 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1389 num_stripes = nr_devices;
1390 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1393 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1398 if (type & BTRFS_BLOCK_GROUP_DUP)
1399 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1401 min_stripe_size = BTRFS_STRIPE_LEN;
1403 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1404 if (!device->in_fs_metadata || !device->bdev ||
1405 device->is_tgtdev_for_dev_replace)
1408 avail_space = device->total_bytes - device->bytes_used;
1410 /* align with stripe_len */
1411 do_div(avail_space, BTRFS_STRIPE_LEN);
1412 avail_space *= BTRFS_STRIPE_LEN;
1415 * In order to avoid overwritting the superblock on the drive,
1416 * btrfs starts at an offset of at least 1MB when doing chunk
1419 skip_space = 1024 * 1024;
1421 /* user can set the offset in fs_info->alloc_start. */
1422 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1423 device->total_bytes)
1424 skip_space = max(fs_info->alloc_start, skip_space);
1427 * btrfs can not use the free space in [0, skip_space - 1],
1428 * we must subtract it from the total. In order to implement
1429 * it, we account the used space in this range first.
1431 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1434 kfree(devices_info);
1438 /* calc the free space in [0, skip_space - 1] */
1439 skip_space -= used_space;
1442 * we can use the free space in [0, skip_space - 1], subtract
1443 * it from the total.
1445 if (avail_space && avail_space >= skip_space)
1446 avail_space -= skip_space;
1450 if (avail_space < min_stripe_size)
1453 devices_info[i].dev = device;
1454 devices_info[i].max_avail = avail_space;
1461 btrfs_descending_sort_devices(devices_info, nr_devices);
1465 while (nr_devices >= min_stripes) {
1466 if (num_stripes > nr_devices)
1467 num_stripes = nr_devices;
1469 if (devices_info[i].max_avail >= min_stripe_size) {
1473 avail_space += devices_info[i].max_avail * num_stripes;
1474 alloc_size = devices_info[i].max_avail;
1475 for (j = i + 1 - num_stripes; j <= i; j++)
1476 devices_info[j].max_avail -= alloc_size;
1482 kfree(devices_info);
1483 *free_bytes = avail_space;
1487 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1489 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1490 struct btrfs_super_block *disk_super = fs_info->super_copy;
1491 struct list_head *head = &fs_info->space_info;
1492 struct btrfs_space_info *found;
1494 u64 total_free_data = 0;
1495 int bits = dentry->d_sb->s_blocksize_bits;
1496 __be32 *fsid = (__be32 *)fs_info->fsid;
1499 /* holding chunk_muext to avoid allocating new chunks */
1500 mutex_lock(&fs_info->chunk_mutex);
1502 list_for_each_entry_rcu(found, head, list) {
1503 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1504 total_free_data += found->disk_total - found->disk_used;
1506 btrfs_account_ro_block_groups_free_space(found);
1509 total_used += found->disk_used;
1513 buf->f_namelen = BTRFS_NAME_LEN;
1514 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1515 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1516 buf->f_bsize = dentry->d_sb->s_blocksize;
1517 buf->f_type = BTRFS_SUPER_MAGIC;
1518 buf->f_bavail = total_free_data;
1519 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1521 mutex_unlock(&fs_info->chunk_mutex);
1524 buf->f_bavail += total_free_data;
1525 buf->f_bavail = buf->f_bavail >> bits;
1526 mutex_unlock(&fs_info->chunk_mutex);
1528 /* We treat it as constant endianness (it doesn't matter _which_)
1529 because we want the fsid to come out the same whether mounted
1530 on a big-endian or little-endian host */
1531 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1532 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1533 /* Mask in the root object ID too, to disambiguate subvols */
1534 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1535 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1540 static void btrfs_kill_super(struct super_block *sb)
1542 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1543 kill_anon_super(sb);
1544 free_fs_info(fs_info);
1547 static struct file_system_type btrfs_fs_type = {
1548 .owner = THIS_MODULE,
1550 .mount = btrfs_mount,
1551 .kill_sb = btrfs_kill_super,
1552 .fs_flags = FS_REQUIRES_DEV,
1554 MODULE_ALIAS_FS("btrfs");
1557 * used by btrfsctl to scan devices when no FS is mounted
1559 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1562 struct btrfs_ioctl_vol_args *vol;
1563 struct btrfs_fs_devices *fs_devices;
1566 if (!capable(CAP_SYS_ADMIN))
1569 vol = memdup_user((void __user *)arg, sizeof(*vol));
1571 return PTR_ERR(vol);
1574 case BTRFS_IOC_SCAN_DEV:
1575 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1576 &btrfs_fs_type, &fs_devices);
1578 case BTRFS_IOC_DEVICES_READY:
1579 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1580 &btrfs_fs_type, &fs_devices);
1583 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1591 static int btrfs_freeze(struct super_block *sb)
1593 struct btrfs_trans_handle *trans;
1594 struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1596 trans = btrfs_attach_transaction_barrier(root);
1597 if (IS_ERR(trans)) {
1598 /* no transaction, don't bother */
1599 if (PTR_ERR(trans) == -ENOENT)
1601 return PTR_ERR(trans);
1603 return btrfs_commit_transaction(trans, root);
1606 static int btrfs_unfreeze(struct super_block *sb)
1611 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1613 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1614 struct btrfs_fs_devices *cur_devices;
1615 struct btrfs_device *dev, *first_dev = NULL;
1616 struct list_head *head;
1617 struct rcu_string *name;
1619 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1620 cur_devices = fs_info->fs_devices;
1621 while (cur_devices) {
1622 head = &cur_devices->devices;
1623 list_for_each_entry(dev, head, dev_list) {
1626 if (!first_dev || dev->devid < first_dev->devid)
1629 cur_devices = cur_devices->seed;
1634 name = rcu_dereference(first_dev->name);
1635 seq_escape(m, name->str, " \t\n\\");
1640 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1644 static const struct super_operations btrfs_super_ops = {
1645 .drop_inode = btrfs_drop_inode,
1646 .evict_inode = btrfs_evict_inode,
1647 .put_super = btrfs_put_super,
1648 .sync_fs = btrfs_sync_fs,
1649 .show_options = btrfs_show_options,
1650 .show_devname = btrfs_show_devname,
1651 .write_inode = btrfs_write_inode,
1652 .alloc_inode = btrfs_alloc_inode,
1653 .destroy_inode = btrfs_destroy_inode,
1654 .statfs = btrfs_statfs,
1655 .remount_fs = btrfs_remount,
1656 .freeze_fs = btrfs_freeze,
1657 .unfreeze_fs = btrfs_unfreeze,
1660 static const struct file_operations btrfs_ctl_fops = {
1661 .unlocked_ioctl = btrfs_control_ioctl,
1662 .compat_ioctl = btrfs_control_ioctl,
1663 .owner = THIS_MODULE,
1664 .llseek = noop_llseek,
1667 static struct miscdevice btrfs_misc = {
1668 .minor = BTRFS_MINOR,
1669 .name = "btrfs-control",
1670 .fops = &btrfs_ctl_fops
1673 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1674 MODULE_ALIAS("devname:btrfs-control");
1676 static int btrfs_interface_init(void)
1678 return misc_register(&btrfs_misc);
1681 static void btrfs_interface_exit(void)
1683 if (misc_deregister(&btrfs_misc) < 0)
1684 printk(KERN_INFO "btrfs: misc_deregister failed for control device\n");
1687 static void btrfs_print_info(void)
1689 printk(KERN_INFO "Btrfs loaded"
1690 #ifdef CONFIG_BTRFS_DEBUG
1693 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1694 ", integrity-checker=on"
1699 static int __init init_btrfs_fs(void)
1703 err = btrfs_init_sysfs();
1707 btrfs_init_compress();
1709 err = btrfs_init_cachep();
1713 err = extent_io_init();
1717 err = extent_map_init();
1719 goto free_extent_io;
1721 err = ordered_data_init();
1723 goto free_extent_map;
1725 err = btrfs_delayed_inode_init();
1727 goto free_ordered_data;
1729 err = btrfs_auto_defrag_init();
1731 goto free_delayed_inode;
1733 err = btrfs_delayed_ref_init();
1735 goto free_auto_defrag;
1737 err = btrfs_interface_init();
1739 goto free_delayed_ref;
1741 err = register_filesystem(&btrfs_fs_type);
1743 goto unregister_ioctl;
1745 btrfs_init_lockdep();
1748 btrfs_test_free_space_cache();
1753 btrfs_interface_exit();
1755 btrfs_delayed_ref_exit();
1757 btrfs_auto_defrag_exit();
1759 btrfs_delayed_inode_exit();
1761 ordered_data_exit();
1767 btrfs_destroy_cachep();
1769 btrfs_exit_compress();
1774 static void __exit exit_btrfs_fs(void)
1776 btrfs_destroy_cachep();
1777 btrfs_delayed_ref_exit();
1778 btrfs_auto_defrag_exit();
1779 btrfs_delayed_inode_exit();
1780 ordered_data_exit();
1783 btrfs_interface_exit();
1784 unregister_filesystem(&btrfs_fs_type);
1786 btrfs_cleanup_fs_uuids();
1787 btrfs_exit_compress();
1790 module_init(init_btrfs_fs)
1791 module_exit(exit_btrfs_fs)
1793 MODULE_LICENSE("GPL");