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: NTrond Myklebust <trond.myklebust@hammerspace.com>

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:

fs/nfs/nfs4proc.c

@@ -407,6 +407,11 @@ static int nfs4_do_handle_exception(struct nfs_server *server,
 	switch(errorcode) {
 		case 0:
 			return 0;
+		case -NFS4ERR_BADHANDLE:
+		case -ESTALE:
+			if (inode != NULL && S_ISREG(inode->i_mode))
+				pnfs_destroy_layout(NFS_I(inode));
+			break;
 		case -NFS4ERR_DELEG_REVOKED:
 		case -NFS4ERR_ADMIN_REVOKED:
 		case -NFS4ERR_EXPIRED: