diff options
Diffstat (limited to 'fs/btrfs/sysfs.c')
| -rw-r--r-- | fs/btrfs/sysfs.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index ec6315391111..669fdf777b6c 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -355,6 +355,49 @@ static const struct attribute *allocation_attrs[] = { NULL, }; +static ssize_t btrfs_label_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + return snprintf(buf, PAGE_SIZE, "%s\n", fs_info->super_copy->label); +} + +static ssize_t btrfs_label_store(struct kobject *kobj, + struct kobj_attribute *a, + const char *buf, size_t len) +{ + struct btrfs_fs_info *fs_info = to_fs_info(kobj); + struct btrfs_trans_handle *trans; + struct btrfs_root *root = fs_info->fs_root; + int ret; + + if (len >= BTRFS_LABEL_SIZE) { + pr_err("btrfs: unable to set label with more than %d bytes\n", + BTRFS_LABEL_SIZE - 1); + return -EINVAL; + } + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + spin_lock(&root->fs_info->super_lock); + strcpy(fs_info->super_copy->label, buf); + spin_unlock(&root->fs_info->super_lock); + ret = btrfs_commit_transaction(trans, root); + + if (!ret) + return len; + + return ret; +} +BTRFS_ATTR_RW(label, 0644, btrfs_label_show, btrfs_label_store); + +static struct attribute *btrfs_attrs[] = { + BTRFS_ATTR_PTR(label), + NULL, +}; + static void btrfs_release_super_kobj(struct kobject *kobj) { struct btrfs_fs_info *fs_info = to_fs_info(kobj); @@ -364,6 +407,7 @@ static void btrfs_release_super_kobj(struct kobject *kobj) static struct kobj_type btrfs_ktype = { .sysfs_ops = &kobj_sysfs_ops, .release = btrfs_release_super_kobj, + .default_attrs = btrfs_attrs, }; static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj) |