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"
57 #include "rcu-string.h"
59 #define CREATE_TRACE_POINTS
60 #include <trace/events/btrfs.h>
62 static const struct super_operations btrfs_super_ops;
63 static struct file_system_type btrfs_fs_type;
65 static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
72 errstr = "IO failure";
75 errstr = "Out of memory";
78 errstr = "Readonly filesystem";
81 errstr = "Object already exists";
85 if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
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 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
103 static void save_error_info(struct btrfs_fs_info *fs_info)
105 __save_error_info(fs_info);
108 /* btrfs handle error by forcing the filesystem readonly */
109 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
111 struct super_block *sb = fs_info->sb;
113 if (sb->s_flags & MS_RDONLY)
116 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
117 sb->s_flags |= MS_RDONLY;
118 printk(KERN_INFO "btrfs is forced readonly\n");
119 __btrfs_scrub_cancel(fs_info);
126 * __btrfs_std_error decodes expected errors from the caller and
127 * invokes the approciate error response.
129 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
130 unsigned int line, int errno, const char *fmt, ...)
132 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(fs_info, errno, nbuf);
147 struct va_format vaf = {
152 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s (%pV)\n",
153 sb->s_id, function, line, errstr, &vaf);
155 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
156 sb->s_id, function, line, errstr);
159 /* Don't go through full error handling during mount */
160 if (sb->s_flags & MS_BORN) {
161 save_error_info(fs_info);
162 btrfs_handle_error(fs_info);
167 static const char * const logtypes[] = {
178 void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...)
180 struct super_block *sb = fs_info->sb;
182 struct va_format vaf;
184 const char *type = logtypes[4];
189 kern_level = printk_get_level(fmt);
191 size_t size = printk_skip_level(fmt) - fmt;
192 memcpy(lvl, fmt, size);
195 type = logtypes[kern_level - '0'];
202 printk("%sBTRFS %s (device %s): %pV", lvl, type, sb->s_id, &vaf);
209 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
210 unsigned int line, int errno, const char *fmt, ...)
212 struct super_block *sb = fs_info->sb;
215 * Special case: if the error is EROFS, and we're already
216 * under MS_RDONLY, then it is safe here.
218 if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
221 /* Don't go through full error handling during mount */
222 if (sb->s_flags & MS_BORN) {
223 save_error_info(fs_info);
224 btrfs_handle_error(fs_info);
230 * We only mark the transaction aborted and then set the file system read-only.
231 * This will prevent new transactions from starting or trying to join this
234 * This means that error recovery at the call site is limited to freeing
235 * any local memory allocations and passing the error code up without
236 * further cleanup. The transaction should complete as it normally would
237 * in the call path but will return -EIO.
239 * We'll complete the cleanup in btrfs_end_transaction and
240 * btrfs_commit_transaction.
242 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
243 struct btrfs_root *root, const char *function,
244 unsigned int line, int errno)
246 WARN_ONCE(1, KERN_DEBUG "btrfs: Transaction aborted");
247 trans->aborted = errno;
248 /* Nothing used. The other threads that have joined this
249 * transaction may be able to continue. */
250 if (!trans->blocks_used) {
251 btrfs_printk(root->fs_info, "Aborting unused transaction.\n");
254 trans->transaction->aborted = errno;
255 __btrfs_std_error(root->fs_info, function, line, errno, NULL);
258 * __btrfs_panic decodes unexpected, fatal errors from the caller,
259 * issues an alert, and either panics or BUGs, depending on mount options.
261 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
262 unsigned int line, int errno, const char *fmt, ...)
265 char *s_id = "<unknown>";
267 struct va_format vaf = { .fmt = fmt };
271 s_id = fs_info->sb->s_id;
276 errstr = btrfs_decode_error(fs_info, errno, nbuf);
277 if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR)
278 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
279 s_id, function, line, &vaf, errstr);
281 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n",
282 s_id, function, line, &vaf, errstr);
284 /* Caller calls BUG() */
287 static void btrfs_put_super(struct super_block *sb)
289 (void)close_ctree(btrfs_sb(sb)->tree_root);
290 /* FIXME: need to fix VFS to return error? */
291 /* AV: return it _where_? ->put_super() can be triggered by any number
292 * of async events, up to and including delivery of SIGKILL to the
293 * last process that kept it busy. Or segfault in the aforementioned
294 * process... Whom would you report that to?
299 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
300 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
301 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
302 Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
303 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
304 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
305 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
306 Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
307 Opt_check_integrity, Opt_check_integrity_including_extent_data,
308 Opt_check_integrity_print_mask, Opt_fatal_errors,
312 static match_table_t tokens = {
313 {Opt_degraded, "degraded"},
314 {Opt_subvol, "subvol=%s"},
315 {Opt_subvolid, "subvolid=%d"},
316 {Opt_device, "device=%s"},
317 {Opt_nodatasum, "nodatasum"},
318 {Opt_nodatacow, "nodatacow"},
319 {Opt_nobarrier, "nobarrier"},
320 {Opt_max_inline, "max_inline=%s"},
321 {Opt_alloc_start, "alloc_start=%s"},
322 {Opt_thread_pool, "thread_pool=%d"},
323 {Opt_compress, "compress"},
324 {Opt_compress_type, "compress=%s"},
325 {Opt_compress_force, "compress-force"},
326 {Opt_compress_force_type, "compress-force=%s"},
328 {Opt_ssd_spread, "ssd_spread"},
329 {Opt_nossd, "nossd"},
330 {Opt_noacl, "noacl"},
331 {Opt_notreelog, "notreelog"},
332 {Opt_flushoncommit, "flushoncommit"},
333 {Opt_ratio, "metadata_ratio=%d"},
334 {Opt_discard, "discard"},
335 {Opt_space_cache, "space_cache"},
336 {Opt_clear_cache, "clear_cache"},
337 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
338 {Opt_enospc_debug, "enospc_debug"},
339 {Opt_subvolrootid, "subvolrootid=%d"},
340 {Opt_defrag, "autodefrag"},
341 {Opt_inode_cache, "inode_cache"},
342 {Opt_no_space_cache, "nospace_cache"},
343 {Opt_recovery, "recovery"},
344 {Opt_skip_balance, "skip_balance"},
345 {Opt_check_integrity, "check_int"},
346 {Opt_check_integrity_including_extent_data, "check_int_data"},
347 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
348 {Opt_fatal_errors, "fatal_errors=%s"},
353 * Regular mount options parser. Everything that is needed only when
354 * reading in a new superblock is parsed here.
355 * XXX JDM: This needs to be cleaned up for remount.
357 int btrfs_parse_options(struct btrfs_root *root, char *options)
359 struct btrfs_fs_info *info = root->fs_info;
360 substring_t args[MAX_OPT_ARGS];
361 char *p, *num, *orig = NULL;
366 bool compress_force = false;
368 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
370 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
376 * strsep changes the string, duplicate it because parse_options
379 options = kstrdup(options, GFP_NOFS);
385 while ((p = strsep(&options, ",")) != NULL) {
390 token = match_token(p, tokens, args);
393 printk(KERN_INFO "btrfs: allowing degraded mounts\n");
394 btrfs_set_opt(info->mount_opt, DEGRADED);
398 case Opt_subvolrootid:
401 * These are parsed by btrfs_parse_early_options
402 * and can be happily ignored here.
406 printk(KERN_INFO "btrfs: setting nodatasum\n");
407 btrfs_set_opt(info->mount_opt, NODATASUM);
410 printk(KERN_INFO "btrfs: setting nodatacow\n");
411 btrfs_set_opt(info->mount_opt, NODATACOW);
412 btrfs_set_opt(info->mount_opt, NODATASUM);
414 case Opt_compress_force:
415 case Opt_compress_force_type:
416 compress_force = true;
418 case Opt_compress_type:
419 if (token == Opt_compress ||
420 token == Opt_compress_force ||
421 strcmp(args[0].from, "zlib") == 0) {
422 compress_type = "zlib";
423 info->compress_type = BTRFS_COMPRESS_ZLIB;
424 btrfs_set_opt(info->mount_opt, COMPRESS);
425 } else if (strcmp(args[0].from, "lzo") == 0) {
426 compress_type = "lzo";
427 info->compress_type = BTRFS_COMPRESS_LZO;
428 btrfs_set_opt(info->mount_opt, COMPRESS);
429 btrfs_set_fs_incompat(info, COMPRESS_LZO);
430 } else if (strncmp(args[0].from, "no", 2) == 0) {
431 compress_type = "no";
432 info->compress_type = BTRFS_COMPRESS_NONE;
433 btrfs_clear_opt(info->mount_opt, COMPRESS);
434 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
435 compress_force = false;
441 if (compress_force) {
442 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
443 pr_info("btrfs: force %s compression\n",
446 pr_info("btrfs: use %s compression\n",
450 printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
451 btrfs_set_opt(info->mount_opt, SSD);
454 printk(KERN_INFO "btrfs: use spread ssd "
455 "allocation scheme\n");
456 btrfs_set_opt(info->mount_opt, SSD);
457 btrfs_set_opt(info->mount_opt, SSD_SPREAD);
460 printk(KERN_INFO "btrfs: not using ssd allocation "
462 btrfs_set_opt(info->mount_opt, NOSSD);
463 btrfs_clear_opt(info->mount_opt, SSD);
464 btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
467 printk(KERN_INFO "btrfs: turning off barriers\n");
468 btrfs_set_opt(info->mount_opt, NOBARRIER);
470 case Opt_thread_pool:
472 match_int(&args[0], &intarg);
474 info->thread_pool_size = intarg;
477 num = match_strdup(&args[0]);
479 info->max_inline = memparse(num, NULL);
482 if (info->max_inline) {
483 info->max_inline = max_t(u64,
487 printk(KERN_INFO "btrfs: max_inline at %llu\n",
488 (unsigned long long)info->max_inline);
491 case Opt_alloc_start:
492 num = match_strdup(&args[0]);
494 info->alloc_start = memparse(num, NULL);
497 "btrfs: allocations start at %llu\n",
498 (unsigned long long)info->alloc_start);
502 root->fs_info->sb->s_flags &= ~MS_POSIXACL;
505 printk(KERN_INFO "btrfs: disabling tree log\n");
506 btrfs_set_opt(info->mount_opt, NOTREELOG);
508 case Opt_flushoncommit:
509 printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
510 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
514 match_int(&args[0], &intarg);
516 info->metadata_ratio = intarg;
517 printk(KERN_INFO "btrfs: metadata ratio %d\n",
518 info->metadata_ratio);
522 btrfs_set_opt(info->mount_opt, DISCARD);
524 case Opt_space_cache:
525 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
527 case Opt_no_space_cache:
528 printk(KERN_INFO "btrfs: disabling disk space caching\n");
529 btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
531 case Opt_inode_cache:
532 printk(KERN_INFO "btrfs: enabling inode map caching\n");
533 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
535 case Opt_clear_cache:
536 printk(KERN_INFO "btrfs: force clearing of disk cache\n");
537 btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
539 case Opt_user_subvol_rm_allowed:
540 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
542 case Opt_enospc_debug:
543 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
546 printk(KERN_INFO "btrfs: enabling auto defrag");
547 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
550 printk(KERN_INFO "btrfs: enabling auto recovery");
551 btrfs_set_opt(info->mount_opt, RECOVERY);
553 case Opt_skip_balance:
554 btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
556 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
557 case Opt_check_integrity_including_extent_data:
558 printk(KERN_INFO "btrfs: enabling check integrity"
559 " including extent data\n");
560 btrfs_set_opt(info->mount_opt,
561 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
562 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
564 case Opt_check_integrity:
565 printk(KERN_INFO "btrfs: enabling check integrity\n");
566 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
568 case Opt_check_integrity_print_mask:
570 match_int(&args[0], &intarg);
572 info->check_integrity_print_mask = intarg;
573 printk(KERN_INFO "btrfs:"
574 " check_integrity_print_mask 0x%x\n",
575 info->check_integrity_print_mask);
579 case Opt_check_integrity_including_extent_data:
580 case Opt_check_integrity:
581 case Opt_check_integrity_print_mask:
582 printk(KERN_ERR "btrfs: support for check_integrity*"
583 " not compiled in!\n");
587 case Opt_fatal_errors:
588 if (strcmp(args[0].from, "panic") == 0)
589 btrfs_set_opt(info->mount_opt,
590 PANIC_ON_FATAL_ERROR);
591 else if (strcmp(args[0].from, "bug") == 0)
592 btrfs_clear_opt(info->mount_opt,
593 PANIC_ON_FATAL_ERROR);
600 printk(KERN_INFO "btrfs: unrecognized mount option "
609 if (!ret && btrfs_test_opt(root, SPACE_CACHE))
610 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
616 * Parse mount options that are required early in the mount process.
618 * All other options will be parsed on much later in the mount process and
619 * only when we need to allocate a new super block.
621 static int btrfs_parse_early_options(const char *options, fmode_t flags,
622 void *holder, char **subvol_name, u64 *subvol_objectid,
623 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
625 substring_t args[MAX_OPT_ARGS];
626 char *device_name, *opts, *orig, *p;
634 * strsep changes the string, duplicate it because parse_options
637 opts = kstrdup(options, GFP_KERNEL);
642 while ((p = strsep(&opts, ",")) != NULL) {
647 token = match_token(p, tokens, args);
651 *subvol_name = match_strdup(&args[0]);
655 error = match_int(&args[0], &intarg);
657 /* we want the original fs_tree */
660 BTRFS_FS_TREE_OBJECTID;
662 *subvol_objectid = intarg;
665 case Opt_subvolrootid:
667 error = match_int(&args[0], &intarg);
669 /* we want the original fs_tree */
672 BTRFS_FS_TREE_OBJECTID;
674 *subvol_rootid = intarg;
678 device_name = match_strdup(&args[0]);
683 error = btrfs_scan_one_device(device_name,
684 flags, holder, fs_devices);
699 static struct dentry *get_default_root(struct super_block *sb,
702 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
703 struct btrfs_root *root = fs_info->tree_root;
704 struct btrfs_root *new_root;
705 struct btrfs_dir_item *di;
706 struct btrfs_path *path;
707 struct btrfs_key location;
713 * We have a specific subvol we want to mount, just setup location and
714 * go look up the root.
716 if (subvol_objectid) {
717 location.objectid = subvol_objectid;
718 location.type = BTRFS_ROOT_ITEM_KEY;
719 location.offset = (u64)-1;
723 path = btrfs_alloc_path();
725 return ERR_PTR(-ENOMEM);
726 path->leave_spinning = 1;
729 * Find the "default" dir item which points to the root item that we
730 * will mount by default if we haven't been given a specific subvolume
733 dir_id = btrfs_super_root_dir(fs_info->super_copy);
734 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
736 btrfs_free_path(path);
741 * Ok the default dir item isn't there. This is weird since
742 * it's always been there, but don't freak out, just try and
743 * mount to root most subvolume.
745 btrfs_free_path(path);
746 dir_id = BTRFS_FIRST_FREE_OBJECTID;
747 new_root = fs_info->fs_root;
751 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
752 btrfs_free_path(path);
755 new_root = btrfs_read_fs_root_no_name(fs_info, &location);
756 if (IS_ERR(new_root))
757 return ERR_CAST(new_root);
759 if (btrfs_root_refs(&new_root->root_item) == 0)
760 return ERR_PTR(-ENOENT);
762 dir_id = btrfs_root_dirid(&new_root->root_item);
764 location.objectid = dir_id;
765 location.type = BTRFS_INODE_ITEM_KEY;
768 inode = btrfs_iget(sb, &location, new_root, &new);
770 return ERR_CAST(inode);
773 * If we're just mounting the root most subvol put the inode and return
774 * a reference to the dentry. We will have already gotten a reference
775 * to the inode in btrfs_fill_super so we're good to go.
777 if (!new && sb->s_root->d_inode == inode) {
779 return dget(sb->s_root);
782 return d_obtain_alias(inode);
785 static int btrfs_fill_super(struct super_block *sb,
786 struct btrfs_fs_devices *fs_devices,
787 void *data, int silent)
790 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
791 struct btrfs_key key;
794 sb->s_maxbytes = MAX_LFS_FILESIZE;
795 sb->s_magic = BTRFS_SUPER_MAGIC;
796 sb->s_op = &btrfs_super_ops;
797 sb->s_d_op = &btrfs_dentry_operations;
798 sb->s_export_op = &btrfs_export_ops;
799 sb->s_xattr = btrfs_xattr_handlers;
801 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
802 sb->s_flags |= MS_POSIXACL;
804 sb->s_flags |= MS_I_VERSION;
805 err = open_ctree(sb, fs_devices, (char *)data);
807 printk("btrfs: open_ctree failed\n");
811 key.objectid = BTRFS_FIRST_FREE_OBJECTID;
812 key.type = BTRFS_INODE_ITEM_KEY;
814 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
816 err = PTR_ERR(inode);
820 sb->s_root = d_make_root(inode);
826 save_mount_options(sb, data);
827 cleancache_init_fs(sb);
828 sb->s_flags |= MS_ACTIVE;
832 close_ctree(fs_info->tree_root);
836 int btrfs_sync_fs(struct super_block *sb, int wait)
838 struct btrfs_trans_handle *trans;
839 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
840 struct btrfs_root *root = fs_info->tree_root;
843 trace_btrfs_sync_fs(wait);
846 filemap_flush(fs_info->btree_inode->i_mapping);
850 btrfs_wait_ordered_extents(root, 0, 0);
852 trans = btrfs_start_transaction(root, 0);
854 return PTR_ERR(trans);
855 ret = btrfs_commit_transaction(trans, root);
859 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
861 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
862 struct btrfs_root *root = info->tree_root;
865 if (btrfs_test_opt(root, DEGRADED))
866 seq_puts(seq, ",degraded");
867 if (btrfs_test_opt(root, NODATASUM))
868 seq_puts(seq, ",nodatasum");
869 if (btrfs_test_opt(root, NODATACOW))
870 seq_puts(seq, ",nodatacow");
871 if (btrfs_test_opt(root, NOBARRIER))
872 seq_puts(seq, ",nobarrier");
873 if (info->max_inline != 8192 * 1024)
874 seq_printf(seq, ",max_inline=%llu",
875 (unsigned long long)info->max_inline);
876 if (info->alloc_start != 0)
877 seq_printf(seq, ",alloc_start=%llu",
878 (unsigned long long)info->alloc_start);
879 if (info->thread_pool_size != min_t(unsigned long,
880 num_online_cpus() + 2, 8))
881 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
882 if (btrfs_test_opt(root, COMPRESS)) {
883 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
884 compress_type = "zlib";
886 compress_type = "lzo";
887 if (btrfs_test_opt(root, FORCE_COMPRESS))
888 seq_printf(seq, ",compress-force=%s", compress_type);
890 seq_printf(seq, ",compress=%s", compress_type);
892 if (btrfs_test_opt(root, NOSSD))
893 seq_puts(seq, ",nossd");
894 if (btrfs_test_opt(root, SSD_SPREAD))
895 seq_puts(seq, ",ssd_spread");
896 else if (btrfs_test_opt(root, SSD))
897 seq_puts(seq, ",ssd");
898 if (btrfs_test_opt(root, NOTREELOG))
899 seq_puts(seq, ",notreelog");
900 if (btrfs_test_opt(root, FLUSHONCOMMIT))
901 seq_puts(seq, ",flushoncommit");
902 if (btrfs_test_opt(root, DISCARD))
903 seq_puts(seq, ",discard");
904 if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
905 seq_puts(seq, ",noacl");
906 if (btrfs_test_opt(root, SPACE_CACHE))
907 seq_puts(seq, ",space_cache");
909 seq_puts(seq, ",nospace_cache");
910 if (btrfs_test_opt(root, CLEAR_CACHE))
911 seq_puts(seq, ",clear_cache");
912 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
913 seq_puts(seq, ",user_subvol_rm_allowed");
914 if (btrfs_test_opt(root, ENOSPC_DEBUG))
915 seq_puts(seq, ",enospc_debug");
916 if (btrfs_test_opt(root, AUTO_DEFRAG))
917 seq_puts(seq, ",autodefrag");
918 if (btrfs_test_opt(root, INODE_MAP_CACHE))
919 seq_puts(seq, ",inode_cache");
920 if (btrfs_test_opt(root, SKIP_BALANCE))
921 seq_puts(seq, ",skip_balance");
922 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
923 seq_puts(seq, ",fatal_errors=panic");
927 static int btrfs_test_super(struct super_block *s, void *data)
929 struct btrfs_fs_info *p = data;
930 struct btrfs_fs_info *fs_info = btrfs_sb(s);
932 return fs_info->fs_devices == p->fs_devices;
935 static int btrfs_set_super(struct super_block *s, void *data)
937 int err = set_anon_super(s, data);
944 * subvolumes are identified by ino 256
946 static inline int is_subvolume_inode(struct inode *inode)
948 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
954 * This will strip out the subvol=%s argument for an argument string and add
955 * subvolid=0 to make sure we get the actual tree root for path walking to the
958 static char *setup_root_args(char *args)
960 unsigned len = strlen(args) + 2 + 1;
961 char *src, *dst, *buf;
964 * We need the same args as before, but with this substitution:
965 * s!subvol=[^,]+!subvolid=0!
967 * Since the replacement string is up to 2 bytes longer than the
968 * original, allocate strlen(args) + 2 + 1 bytes.
971 src = strstr(args, "subvol=");
972 /* This shouldn't happen, but just in case.. */
976 buf = dst = kmalloc(len, GFP_NOFS);
981 * If the subvol= arg is not at the start of the string,
982 * copy whatever precedes it into buf.
990 strcpy(dst, "subvolid=0");
991 dst += strlen("subvolid=0");
994 * If there is a "," after the original subvol=... string,
995 * copy that suffix into our buffer. Otherwise, we're done.
997 src = strchr(src, ',');
1004 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1005 const char *device_name, char *data)
1007 struct dentry *root;
1008 struct vfsmount *mnt;
1011 newargs = setup_root_args(data);
1013 return ERR_PTR(-ENOMEM);
1014 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1018 return ERR_CAST(mnt);
1020 root = mount_subtree(mnt, subvol_name);
1022 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1023 struct super_block *s = root->d_sb;
1025 root = ERR_PTR(-EINVAL);
1026 deactivate_locked_super(s);
1027 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
1035 * Find a superblock for the given device / mount point.
1037 * Note: This is based on get_sb_bdev from fs/super.c with a few additions
1038 * for multiple device setup. Make sure to keep it in sync.
1040 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1041 const char *device_name, void *data)
1043 struct block_device *bdev = NULL;
1044 struct super_block *s;
1045 struct dentry *root;
1046 struct btrfs_fs_devices *fs_devices = NULL;
1047 struct btrfs_fs_info *fs_info = NULL;
1048 fmode_t mode = FMODE_READ;
1049 char *subvol_name = NULL;
1050 u64 subvol_objectid = 0;
1051 u64 subvol_rootid = 0;
1054 if (!(flags & MS_RDONLY))
1055 mode |= FMODE_WRITE;
1057 error = btrfs_parse_early_options(data, mode, fs_type,
1058 &subvol_name, &subvol_objectid,
1059 &subvol_rootid, &fs_devices);
1062 return ERR_PTR(error);
1066 root = mount_subvol(subvol_name, flags, device_name, data);
1071 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1073 return ERR_PTR(error);
1076 * Setup a dummy root and fs_info for test/set super. This is because
1077 * we don't actually fill this stuff out until open_ctree, but we need
1078 * it for searching for existing supers, so this lets us do that and
1079 * then open_ctree will properly initialize everything later.
1081 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1083 return ERR_PTR(-ENOMEM);
1085 fs_info->fs_devices = fs_devices;
1087 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1088 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1089 if (!fs_info->super_copy || !fs_info->super_for_commit) {
1094 error = btrfs_open_devices(fs_devices, mode, fs_type);
1098 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1100 goto error_close_devices;
1103 bdev = fs_devices->latest_bdev;
1104 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1108 goto error_close_devices;
1112 btrfs_close_devices(fs_devices);
1113 free_fs_info(fs_info);
1114 if ((flags ^ s->s_flags) & MS_RDONLY)
1117 char b[BDEVNAME_SIZE];
1119 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1120 btrfs_sb(s)->bdev_holder = fs_type;
1121 error = btrfs_fill_super(s, fs_devices, data,
1122 flags & MS_SILENT ? 1 : 0);
1125 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1127 deactivate_locked_super(s);
1131 error_close_devices:
1132 btrfs_close_devices(fs_devices);
1134 free_fs_info(fs_info);
1135 return ERR_PTR(error);
1138 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1140 spin_lock_irq(&workers->lock);
1141 workers->max_workers = new_limit;
1142 spin_unlock_irq(&workers->lock);
1145 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1146 int new_pool_size, int old_pool_size)
1148 if (new_pool_size == old_pool_size)
1151 fs_info->thread_pool_size = new_pool_size;
1153 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1154 old_pool_size, new_pool_size);
1156 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1157 btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1158 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1159 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1160 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1161 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1162 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1163 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1164 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1165 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1166 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1167 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1168 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1169 btrfs_set_max_workers(&fs_info->scrub_workers, new_pool_size);
1172 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1174 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1175 struct btrfs_root *root = fs_info->tree_root;
1176 unsigned old_flags = sb->s_flags;
1177 unsigned long old_opts = fs_info->mount_opt;
1178 unsigned long old_compress_type = fs_info->compress_type;
1179 u64 old_max_inline = fs_info->max_inline;
1180 u64 old_alloc_start = fs_info->alloc_start;
1181 int old_thread_pool_size = fs_info->thread_pool_size;
1182 unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1185 ret = btrfs_parse_options(root, data);
1191 btrfs_resize_thread_pool(fs_info,
1192 fs_info->thread_pool_size, old_thread_pool_size);
1194 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1197 if (*flags & MS_RDONLY) {
1198 sb->s_flags |= MS_RDONLY;
1200 ret = btrfs_commit_super(root);
1204 if (fs_info->fs_devices->rw_devices == 0) {
1209 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1214 ret = btrfs_cleanup_fs_roots(fs_info);
1218 /* recover relocation */
1219 ret = btrfs_recover_relocation(root);
1223 ret = btrfs_resume_balance_async(fs_info);
1227 sb->s_flags &= ~MS_RDONLY;
1233 /* We've hit an error - don't reset MS_RDONLY */
1234 if (sb->s_flags & MS_RDONLY)
1235 old_flags |= MS_RDONLY;
1236 sb->s_flags = old_flags;
1237 fs_info->mount_opt = old_opts;
1238 fs_info->compress_type = old_compress_type;
1239 fs_info->max_inline = old_max_inline;
1240 fs_info->alloc_start = old_alloc_start;
1241 btrfs_resize_thread_pool(fs_info,
1242 old_thread_pool_size, fs_info->thread_pool_size);
1243 fs_info->metadata_ratio = old_metadata_ratio;
1247 /* Used to sort the devices by max_avail(descending sort) */
1248 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1249 const void *dev_info2)
1251 if (((struct btrfs_device_info *)dev_info1)->max_avail >
1252 ((struct btrfs_device_info *)dev_info2)->max_avail)
1254 else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1255 ((struct btrfs_device_info *)dev_info2)->max_avail)
1262 * sort the devices by max_avail, in which max free extent size of each device
1263 * is stored.(Descending Sort)
1265 static inline void btrfs_descending_sort_devices(
1266 struct btrfs_device_info *devices,
1269 sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1270 btrfs_cmp_device_free_bytes, NULL);
1274 * The helper to calc the free space on the devices that can be used to store
1277 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1279 struct btrfs_fs_info *fs_info = root->fs_info;
1280 struct btrfs_device_info *devices_info;
1281 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1282 struct btrfs_device *device;
1287 u64 min_stripe_size;
1288 int min_stripes = 1, num_stripes = 1;
1289 int i = 0, nr_devices;
1292 nr_devices = fs_info->fs_devices->open_devices;
1293 BUG_ON(!nr_devices);
1295 devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1300 /* calc min stripe number for data space alloction */
1301 type = btrfs_get_alloc_profile(root, 1);
1302 if (type & BTRFS_BLOCK_GROUP_RAID0) {
1304 num_stripes = nr_devices;
1305 } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1308 } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1313 if (type & BTRFS_BLOCK_GROUP_DUP)
1314 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1316 min_stripe_size = BTRFS_STRIPE_LEN;
1318 list_for_each_entry(device, &fs_devices->devices, dev_list) {
1319 if (!device->in_fs_metadata || !device->bdev)
1322 avail_space = device->total_bytes - device->bytes_used;
1324 /* align with stripe_len */
1325 do_div(avail_space, BTRFS_STRIPE_LEN);
1326 avail_space *= BTRFS_STRIPE_LEN;
1329 * In order to avoid overwritting the superblock on the drive,
1330 * btrfs starts at an offset of at least 1MB when doing chunk
1333 skip_space = 1024 * 1024;
1335 /* user can set the offset in fs_info->alloc_start. */
1336 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1337 device->total_bytes)
1338 skip_space = max(fs_info->alloc_start, skip_space);
1341 * btrfs can not use the free space in [0, skip_space - 1],
1342 * we must subtract it from the total. In order to implement
1343 * it, we account the used space in this range first.
1345 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1348 kfree(devices_info);
1352 /* calc the free space in [0, skip_space - 1] */
1353 skip_space -= used_space;
1356 * we can use the free space in [0, skip_space - 1], subtract
1357 * it from the total.
1359 if (avail_space && avail_space >= skip_space)
1360 avail_space -= skip_space;
1364 if (avail_space < min_stripe_size)
1367 devices_info[i].dev = device;
1368 devices_info[i].max_avail = avail_space;
1375 btrfs_descending_sort_devices(devices_info, nr_devices);
1379 while (nr_devices >= min_stripes) {
1380 if (num_stripes > nr_devices)
1381 num_stripes = nr_devices;
1383 if (devices_info[i].max_avail >= min_stripe_size) {
1387 avail_space += devices_info[i].max_avail * num_stripes;
1388 alloc_size = devices_info[i].max_avail;
1389 for (j = i + 1 - num_stripes; j <= i; j++)
1390 devices_info[j].max_avail -= alloc_size;
1396 kfree(devices_info);
1397 *free_bytes = avail_space;
1401 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1403 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1404 struct btrfs_super_block *disk_super = fs_info->super_copy;
1405 struct list_head *head = &fs_info->space_info;
1406 struct btrfs_space_info *found;
1408 u64 total_free_data = 0;
1409 int bits = dentry->d_sb->s_blocksize_bits;
1410 __be32 *fsid = (__be32 *)fs_info->fsid;
1413 /* holding chunk_muext to avoid allocating new chunks */
1414 mutex_lock(&fs_info->chunk_mutex);
1416 list_for_each_entry_rcu(found, head, list) {
1417 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1418 total_free_data += found->disk_total - found->disk_used;
1420 btrfs_account_ro_block_groups_free_space(found);
1423 total_used += found->disk_used;
1427 buf->f_namelen = BTRFS_NAME_LEN;
1428 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1429 buf->f_bfree = buf->f_blocks - (total_used >> bits);
1430 buf->f_bsize = dentry->d_sb->s_blocksize;
1431 buf->f_type = BTRFS_SUPER_MAGIC;
1432 buf->f_bavail = total_free_data;
1433 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1435 mutex_unlock(&fs_info->chunk_mutex);
1438 buf->f_bavail += total_free_data;
1439 buf->f_bavail = buf->f_bavail >> bits;
1440 mutex_unlock(&fs_info->chunk_mutex);
1442 /* We treat it as constant endianness (it doesn't matter _which_)
1443 because we want the fsid to come out the same whether mounted
1444 on a big-endian or little-endian host */
1445 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1446 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1447 /* Mask in the root object ID too, to disambiguate subvols */
1448 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1449 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1454 static void btrfs_kill_super(struct super_block *sb)
1456 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1457 kill_anon_super(sb);
1458 free_fs_info(fs_info);
1461 static struct file_system_type btrfs_fs_type = {
1462 .owner = THIS_MODULE,
1464 .mount = btrfs_mount,
1465 .kill_sb = btrfs_kill_super,
1466 .fs_flags = FS_REQUIRES_DEV,
1470 * used by btrfsctl to scan devices when no FS is mounted
1472 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1475 struct btrfs_ioctl_vol_args *vol;
1476 struct btrfs_fs_devices *fs_devices;
1479 if (!capable(CAP_SYS_ADMIN))
1482 vol = memdup_user((void __user *)arg, sizeof(*vol));
1484 return PTR_ERR(vol);
1487 case BTRFS_IOC_SCAN_DEV:
1488 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1489 &btrfs_fs_type, &fs_devices);
1491 case BTRFS_IOC_DEVICES_READY:
1492 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1493 &btrfs_fs_type, &fs_devices);
1496 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1504 static int btrfs_freeze(struct super_block *sb)
1506 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1507 mutex_lock(&fs_info->transaction_kthread_mutex);
1508 mutex_lock(&fs_info->cleaner_mutex);
1512 static int btrfs_unfreeze(struct super_block *sb)
1514 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1515 mutex_unlock(&fs_info->cleaner_mutex);
1516 mutex_unlock(&fs_info->transaction_kthread_mutex);
1520 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1522 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1523 struct btrfs_fs_devices *cur_devices;
1524 struct btrfs_device *dev, *first_dev = NULL;
1525 struct list_head *head;
1526 struct rcu_string *name;
1528 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1529 cur_devices = fs_info->fs_devices;
1530 while (cur_devices) {
1531 head = &cur_devices->devices;
1532 list_for_each_entry(dev, head, dev_list) {
1533 if (!first_dev || dev->devid < first_dev->devid)
1536 cur_devices = cur_devices->seed;
1541 name = rcu_dereference(first_dev->name);
1542 seq_escape(m, name->str, " \t\n\\");
1547 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1551 static const struct super_operations btrfs_super_ops = {
1552 .drop_inode = btrfs_drop_inode,
1553 .evict_inode = btrfs_evict_inode,
1554 .put_super = btrfs_put_super,
1555 .sync_fs = btrfs_sync_fs,
1556 .show_options = btrfs_show_options,
1557 .show_devname = btrfs_show_devname,
1558 .write_inode = btrfs_write_inode,
1559 .alloc_inode = btrfs_alloc_inode,
1560 .destroy_inode = btrfs_destroy_inode,
1561 .statfs = btrfs_statfs,
1562 .remount_fs = btrfs_remount,
1563 .freeze_fs = btrfs_freeze,
1564 .unfreeze_fs = btrfs_unfreeze,
1567 static const struct file_operations btrfs_ctl_fops = {
1568 .unlocked_ioctl = btrfs_control_ioctl,
1569 .compat_ioctl = btrfs_control_ioctl,
1570 .owner = THIS_MODULE,
1571 .llseek = noop_llseek,
1574 static struct miscdevice btrfs_misc = {
1575 .minor = BTRFS_MINOR,
1576 .name = "btrfs-control",
1577 .fops = &btrfs_ctl_fops
1580 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1581 MODULE_ALIAS("devname:btrfs-control");
1583 static int btrfs_interface_init(void)
1585 return misc_register(&btrfs_misc);
1588 static void btrfs_interface_exit(void)
1590 if (misc_deregister(&btrfs_misc) < 0)
1591 printk(KERN_INFO "misc_deregister failed for control device");
1594 static int __init init_btrfs_fs(void)
1598 err = btrfs_init_sysfs();
1602 btrfs_init_compress();
1604 err = btrfs_init_cachep();
1608 err = extent_io_init();
1612 err = extent_map_init();
1614 goto free_extent_io;
1616 err = btrfs_delayed_inode_init();
1618 goto free_extent_map;
1620 err = btrfs_interface_init();
1622 goto free_delayed_inode;
1624 err = register_filesystem(&btrfs_fs_type);
1626 goto unregister_ioctl;
1628 btrfs_init_lockdep();
1630 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1634 btrfs_interface_exit();
1636 btrfs_delayed_inode_exit();
1642 btrfs_destroy_cachep();
1644 btrfs_exit_compress();
1649 static void __exit exit_btrfs_fs(void)
1651 btrfs_destroy_cachep();
1652 btrfs_delayed_inode_exit();
1655 btrfs_interface_exit();
1656 unregister_filesystem(&btrfs_fs_type);
1658 btrfs_cleanup_fs_uuids();
1659 btrfs_exit_compress();
1662 module_init(init_btrfs_fs)
1663 module_exit(exit_btrfs_fs)
1665 MODULE_LICENSE("GPL");