Recover from stateid-type error on SETATTR

Client can receives stateid-type error (eg., BAD_STATEID) on SETATTR when
delegation stateid was used. When no open state exists, in case of application
calling truncate() on the file, client has no state to recover and fails with
EIO.

Instead, upon such error, return the bad delegation and then resend the
SETATTR with a zero stateid.

Signed-off: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4proc.c

@@ -370,8 +370,14 @@ int nfs4_handle_exception(struct nfs_server *server, int errorcode, struct nfs4_
 		case -NFS4ERR_DELEG_REVOKED:
 		case -NFS4ERR_ADMIN_REVOKED:
 		case -NFS4ERR_BAD_STATEID:
-			if (state == NULL)
+			if (state == NULL) {
+				if (inode && nfs4_have_delegation(inode,
+						FMODE_READ)) {
+					nfs4_inode_return_delegation(inode);
+					exception->retry = 1;
+				}
 				break;
+			}
 			ret = nfs4_schedule_stateid_recovery(server, state);
 			if (ret < 0)
 				break;