commit 8c567a7fab6e086a0284eee2db82348521e7120c
Author: Dwight Engen <dwight.engen@oracle.com>
Date:   Thu Aug 15 14:07:38 2013 -0400

    xfs: add capability check to free eofblocks ioctl
    
    Check for CAP_SYS_ADMIN since the caller can truncate preallocated
    blocks from files they do not own nor have write access to. A more
    fine grained access check was considered: require the caller to
    specify their own uid/gid and to use inode_permission to check for
    write, but this would not catch the case of an inode not reachable
    via path traversal from the callers mount namespace.
    
    Add check for read-only filesystem to free eofblocks ioctl.
    
    Reviewed-by: Brian Foster <bfoster@redhat.com>
    Reviewed-by: Dave Chinner <dchinner@redhat.com>
    Reviewed-by: Gao feng <gaofeng@cn.fujitsu.com>
    Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
    Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 20b4c7a..bdebc21 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1618,6 +1618,12 @@ xfs_file_ioctl(
 		if (mp->m_flags & XFS_MOUNT_RDONLY)
 			return -XFS_ERROR(EROFS);
 
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (mp->m_flags & XFS_MOUNT_RDONLY)
+			return -XFS_ERROR(EROFS);
+
 		if (copy_from_user(&eofb, arg, sizeof(eofb)))
 			return -XFS_ERROR(EFAULT);