NFSv4: Always clear the pNFS layout when handling ESTALE

If we get an ESTALE error in response to an RPC call operating on the
file on the MDS, we should immediately cancel the layout for that file.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 4d4a3df..5f59b6f 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -370,6 +370,10 @@ nfs42_layoutstat_done(struct rpc_task *task, void *calldata)
 	switch (task->tk_status) {
 	case 0:
 		break;
+	case -NFS4ERR_BADHANDLE:
+	case -ESTALE:
+		pnfs_destroy_layout(NFS_I(inode));
+		break;
 	case -NFS4ERR_EXPIRED:
 	case -NFS4ERR_ADMIN_REVOKED:
 	case -NFS4ERR_DELEG_REVOKED: