diff options
| author | Miao Xie <miaox@cn.fujitsu.com> | 2012-11-26 08:43:07 +0000 |
|---|---|---|
| committer | Chris Mason <chris.mason@fusionio.com> | 2012-12-16 20:46:09 -0500 |
| commit | 3c04ce01053413007b9df88313b8b8e17272b57b (patch) | |
| tree | 864b9d4285433c812e8d5af10dd453457f51d9f5 | |
| parent | 8cd2807f79b73ef2d8c1cb6b3732dc5758ac7212 (diff) | |
Btrfs: get write access when setting the default subvolume
When wen want to set the default subvolume, we must get write access, or
we will change the R/O file system.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
| -rw-r--r-- | fs/btrfs/ioctl.c | 40 |
1 files changed, 28 insertions, 12 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 7b1f614f51f6..10bc65ed736c 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2843,12 +2843,19 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) struct btrfs_disk_key disk_key; u64 objectid = 0; u64 dir_id; + int ret; if (!capable(CAP_SYS_ADMIN)) return -EPERM; - if (copy_from_user(&objectid, argp, sizeof(objectid))) - return -EFAULT; + ret = mnt_want_write_file(file); + if (ret) + return ret; + + if (copy_from_user(&objectid, argp, sizeof(objectid))) { + ret = -EFAULT; + goto out; + } if (!objectid) objectid = root->root_key.objectid; @@ -2858,21 +2865,28 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) location.offset = (u64)-1; new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); - if (IS_ERR(new_root)) - return PTR_ERR(new_root); + if (IS_ERR(new_root)) { + ret = PTR_ERR(new_root); + goto out; + } - if (btrfs_root_refs(&new_root->root_item) == 0) - return -ENOENT; + if (btrfs_root_refs(&new_root->root_item) == 0) { + ret = -ENOENT; + goto out; + } path = btrfs_alloc_path(); - if (!path) - return -ENOMEM; + if (!path) { + ret = -ENOMEM; + goto out; + } path->leave_spinning = 1; trans = btrfs_start_transaction(root, 1); if (IS_ERR(trans)) { btrfs_free_path(path); - return PTR_ERR(trans); + ret = PTR_ERR(trans); + goto out; } dir_id = btrfs_super_root_dir(root->fs_info->super_copy); @@ -2883,7 +2897,8 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) btrfs_end_transaction(trans, root); printk(KERN_ERR "Umm, you don't have the default dir item, " "this isn't going to work\n"); - return -ENOENT; + ret = -ENOENT; + goto out; } btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key); @@ -2893,8 +2908,9 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp) btrfs_set_fs_incompat(root->fs_info, DEFAULT_SUBVOL); btrfs_end_transaction(trans, root); - - return 0; +out: + mnt_drop_write_file(file); + return ret; } void btrfs_get_block_group_info(struct list_head *groups_list, |