Btrfs: cleanup fs/btrfs/super.c::btrfs_control_ioctl()

- Remove the unused local variable 'len';
- Check return value of kmalloc().

Signed-off-by: Wang Cong <wangcong@zeuux.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 92c9b543deff..795b6246bcdf 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -583,17 +583,18 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
         struct btrfs_ioctl_vol_args *vol;
         struct btrfs_fs_devices *fs_devices;
         int ret = -ENOTTY;
-        int len;
 
         if (!capable(CAP_SYS_ADMIN))
                 return -EPERM;
 
         vol = kmalloc(sizeof(*vol), GFP_KERNEL);
+        if (!vol)
+                return -ENOMEM;
+
         if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
                 ret = -EFAULT;
                 goto out;
         }
-        len = strnlen(vol->name, BTRFS_PATH_NAME_MAX);
 
         switch (cmd) {
         case BTRFS_IOC_SCAN_DEV: