[patch] invalidate NFS attribute cache if setattr fails with ESTALE

[Jaakko Heinonen]

Hi,

Here is a patch which changes nfs_setattrrpc() to invalidate the NFS
attribute cache in case the RPC failed with ESTALE.

The issue was originally reported by Timo Sirainen in PR kern/123755:

> NFS client: open() a file
> NFS server: unlink() the file
> NFS client: fchown() the file -> ESTALE (as expected)
> NFS client: fstat() the file -> success (not expected)

%%%
Index: sys/nfsclient/nfs_vnops.c
===================================================================
--- sys/nfsclient/nfs_vnops.c	(revision 188842)
+++ sys/nfsclient/nfs_vnops.c	(working copy)
@@ -838,6 +838,10 @@ nfs_setattrrpc(struct vnode *vp, struct 
 		nfsm_loadattr(vp, NULL);
 	m_freem(mrep);
 nfsmout:
+	/* Invalidate the attribute cache if the NFS file handle is stale. */
+	if (error == ESTALE)
+		np->n_attrstamp = 0;
+
 	return (error);
 }
 
%%%

Could someone take a look if this could be committed?

-- 
Jaakko