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/sched.h>
20 #include <linux/slab.h>
21 #include <linux/spinlock.h>
22 #include <linux/completion.h>
23 #include <linux/buffer_head.h>
24 #include <linux/kobject.h>
28 #include "transaction.h"
31 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj);
33 static u64 get_features(struct btrfs_fs_info *fs_info,
34 enum btrfs_feature_set set)
36 struct btrfs_super_block *disk_super = fs_info->super_copy;
37 if (set == FEAT_COMPAT)
38 return btrfs_super_compat_flags(disk_super);
39 else if (set == FEAT_COMPAT_RO)
40 return btrfs_super_compat_ro_flags(disk_super);
42 return btrfs_super_incompat_flags(disk_super);
45 static ssize_t btrfs_feature_attr_show(struct kobject *kobj,
46 struct kobj_attribute *a, char *buf)
49 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
51 struct btrfs_feature_attr *fa = to_btrfs_feature_attr(a);
52 u64 features = get_features(fs_info, fa->feature_set);
53 if (features & fa->feature_bit)
57 return snprintf(buf, PAGE_SIZE, "%d\n", val);
60 static umode_t btrfs_feature_visible(struct kobject *kobj,
61 struct attribute *attr, int unused)
63 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
64 umode_t mode = attr->mode;
67 struct btrfs_feature_attr *fa;
70 fa = attr_to_btrfs_feature_attr(attr);
71 features = get_features(fs_info, fa->feature_set);
73 if (!(features & fa->feature_bit))
80 BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF);
81 BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL);
82 BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS);
83 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO);
84 BTRFS_FEAT_ATTR_INCOMPAT(compress_lzov2, COMPRESS_LZOv2);
85 BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA);
86 BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF);
87 BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56);
88 BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA);
90 static struct attribute *btrfs_supported_feature_attrs[] = {
91 BTRFS_FEAT_ATTR_PTR(mixed_backref),
92 BTRFS_FEAT_ATTR_PTR(default_subvol),
93 BTRFS_FEAT_ATTR_PTR(mixed_groups),
94 BTRFS_FEAT_ATTR_PTR(compress_lzo),
95 BTRFS_FEAT_ATTR_PTR(compress_lzov2),
96 BTRFS_FEAT_ATTR_PTR(big_metadata),
97 BTRFS_FEAT_ATTR_PTR(extended_iref),
98 BTRFS_FEAT_ATTR_PTR(raid56),
99 BTRFS_FEAT_ATTR_PTR(skinny_metadata),
103 static const struct attribute_group btrfs_feature_attr_group = {
105 .is_visible = btrfs_feature_visible,
106 .attrs = btrfs_supported_feature_attrs,
109 static void btrfs_release_super_kobj(struct kobject *kobj)
111 struct btrfs_fs_info *fs_info = to_fs_info(kobj);
112 complete(&fs_info->kobj_unregister);
115 static struct kobj_type btrfs_ktype = {
116 .sysfs_ops = &kobj_sysfs_ops,
117 .release = btrfs_release_super_kobj,
120 static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj)
122 if (kobj->ktype != &btrfs_ktype)
124 return container_of(kobj, struct btrfs_fs_info, super_kobj);
127 void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info)
129 kobject_del(&fs_info->super_kobj);
130 kobject_put(&fs_info->super_kobj);
131 wait_for_completion(&fs_info->kobj_unregister);
134 /* /sys/fs/btrfs/ entry */
135 static struct kset *btrfs_kset;
137 int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info)
141 init_completion(&fs_info->kobj_unregister);
142 fs_info->super_kobj.kset = btrfs_kset;
143 error = kobject_init_and_add(&fs_info->super_kobj, &btrfs_ktype, NULL,
144 "%pU", fs_info->fsid);
146 error = sysfs_create_group(&fs_info->super_kobj,
147 &btrfs_feature_attr_group);
149 btrfs_sysfs_remove_one(fs_info);
153 int btrfs_init_sysfs(void)
156 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
160 ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
162 kset_unregister(btrfs_kset);
169 void btrfs_exit_sysfs(void)
171 sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group);
172 kset_unregister(btrfs_kset);