Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: check for read permission on src file in the clone ioctl

diff --combined fs/btrfs/ioctl.c
index e84ef60,9de6c3a..97a9783
--- 1/fs/btrfs/ioctl.c
--- 2/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@@ -39,7 -39,6 +39,7 @@@
  #include <linux/security.h>
  #include <linux/xattr.h>
  #include <linux/vmalloc.h>
 +#include <linux/slab.h>
  #include "compat.h"
  #include "ctree.h"
  #include "disk-io.h"
@@@ -1481,12 -1480,17 +1481,17 @@@ static noinline long btrfs_ioctl_clone(
                ret = -EBADF;
                goto out_drop_write;
        }
+ 
        src = src_file->f_dentry->d_inode;
  
        ret = -EINVAL;
        if (src == inode)
                goto out_fput;
  
+       /* the src must be open for reading */
+       if (!(src_file->f_mode & FMODE_READ))
+               goto out_fput;
+ 
        ret = -EISDIR;
        if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
                goto out_fput;