From patchwork Wed May 1 02:03:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ronnie Sahlberg X-Patchwork-Id: 1093532 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-cifs-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44v1sP4ZCsz9s9N for ; Wed, 1 May 2019 12:03:53 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726559AbfEACDw (ORCPT ); Tue, 30 Apr 2019 22:03:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43444 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726115AbfEACDw (ORCPT ); Tue, 30 Apr 2019 22:03:52 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1553330832C2; Wed, 1 May 2019 02:03:52 +0000 (UTC) Received: from test1135.test.redhat.com (vpn2-54-54.bne.redhat.com [10.64.54.54]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6E48318A46; Wed, 1 May 2019 02:03:51 +0000 (UTC) From: Ronnie Sahlberg To: linux-cifs Cc: Steve French , Stable , Pavel Shilovsky , Ronnie Sahlberg Subject: [PATCH] cifs: fix credits leak for SMB1 oplock breaks Date: Wed, 1 May 2019 12:03:41 +1000 Message-Id: <20190501020341.9146-1-lsahlber@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Wed, 01 May 2019 02:03:52 +0000 (UTC) Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org For SMB1 oplock breaks we would grab one credit while sending the PDU but we would never relese the credit back since we will never receive a response to this from the server. Eventuallt this would lead to a hang once all credits are leaked. Fix this by defining a new flag CIFS_NO_SRV_RSP which indicates that there is no server response to this command and thus we need to add any credits back immediately after sending the PDU. CC: Stable #v5.0+ Signed-off-by: Ronnie Sahlberg Reviewed-by: Pavel Shilovsky --- fs/cifs/cifsglob.h | 1 + fs/cifs/cifssmb.c | 2 +- fs/cifs/transport.c | 10 +++++----- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 621640195713..7a65124f70f9 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1701,6 +1701,7 @@ static inline bool is_retryable_error(int error) #define CIFS_HAS_CREDITS 0x0400 /* already has credits */ #define CIFS_TRANSFORM_REQ 0x0800 /* transform request before sending */ +#define CIFS_NO_SRV_RSP 0x1000 /* there is no server response */ /* Security Flags: indicate type of session setup needed */ #define CIFSSEC_MAY_SIGN 0x00001 diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index f43747c062a7..6050851edcb8 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -2540,7 +2540,7 @@ CIFSSMBLock(const unsigned int xid, struct cifs_tcon *tcon, if (lockType == LOCKING_ANDX_OPLOCK_RELEASE) { /* no response expected */ - flags = CIFS_ASYNC_OP | CIFS_OBREAK_OP; + flags = CIFS_NO_SRV_RSP | CIFS_ASYNC_OP | CIFS_OBREAK_OP; pSMB->Timeout = 0; } else if (waitFlag) { flags = CIFS_BLOCKING_OP; /* blocking operation, no timeout */ diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 5c59c498f56a..5573e38b13f3 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -1073,8 +1073,11 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses, mutex_unlock(&ses->server->srv_mutex); - if (rc < 0) { - /* Sending failed for some reason - return credits back */ + /* + * If sending failed for some reason or it is an oplock break that we + * will not receive a response to - return credits back + */ + if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) { for (i = 0; i < num_rqst; i++) add_credits(ses->server, &credits[i], optype); goto out; @@ -1095,9 +1098,6 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses, smb311_update_preauth_hash(ses, rqst[0].rq_iov, rqst[0].rq_nvec); - if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP) - goto out; - for (i = 0; i < num_rqst; i++) { rc = wait_for_response(ses->server, midQ[i]); if (rc != 0)