xfs: cache negative ACLs if there is no attribute fork

Always set up a negative ACL cache entry if the inode doesn't have an
attribute fork.  That behaves much better than doing this check inside
->check_acl.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c
index 501e4f6..de66691 100644
--- a/fs/xfs/linux-2.6/xfs_iops.c
+++ b/fs/xfs/linux-2.6/xfs_iops.c
@@ -1194,6 +1194,10 @@
 		break;
 	}
 
+	/* if there is no attribute fork no ACL can exist on this inode */
+	if (!XFS_IFORK_Q(ip))
+		cache_no_acl(inode);
+
 	xfs_iflags_clear(ip, XFS_INEW);
 	barrier();