Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754193AbdFEQbz (ORCPT ); Mon, 5 Jun 2017 12:31:55 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60612 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753623AbdFEQbu (ORCPT ); Mon, 5 Jun 2017 12:31:50 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Bryant G. Ly" , Michael Cyr , Nicholas Bellinger Subject: [PATCH 4.11 065/115] ibmvscsis: Fix the incorrect req_lim_delta Date: Mon, 5 Jun 2017 18:17:38 +0200 Message-Id: <20170605153059.885279396@linuxfoundation.org> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170605153056.650217313@linuxfoundation.org> References: <20170605153056.650217313@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2848 Lines: 77 4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryant G. Ly commit 75dbf2d36f6b122ad3c1070fe4bf95f71bbff321 upstream. The current code is not correctly calculating the req_lim_delta. We want to make sure vscsi->credit is always incremented when we do not send a response for the scsi op. Thus for the case where there is a successfully aborted task we need to make sure the vscsi->credit is incremented. v2 - Moves the original location of the vscsi->credit increment to a better spot. Since if we increment credit, the next command we send back will have increased req_lim_delta. But we probably shouldn't be doing that until the aborted cmd is actually released. Otherwise the client will think that it can send a new command, and we could find ourselves short of command elements. Not likely, but could happen. This patch depends on both: commit 25e78531268e ("ibmvscsis: Do not send aborted task response") commit 98883f1b5415 ("ibmvscsis: Clear left-over abort_cmd pointers") Signed-off-by: Bryant G. Ly Reviewed-by: Michael Cyr Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) --- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c +++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c @@ -1791,6 +1791,25 @@ static void ibmvscsis_send_messages(stru list_del(&cmd->list); ibmvscsis_free_cmd_resources(vscsi, cmd); + /* + * With a successfully aborted op + * through LIO we want to increment the + * the vscsi credit so that when we dont + * send a rsp to the original scsi abort + * op (h_send_crq), but the tm rsp to + * the abort is sent, the credit is + * correctly sent with the abort tm rsp. + * We would need 1 for the abort tm rsp + * and 1 credit for the aborted scsi op. + * Thus we need to increment here. + * Also we want to increment the credit + * here because we want to make sure + * cmd is actually released first + * otherwise the client will think it + * it can send a new cmd, and we could + * find ourselves short of cmd elements. + */ + vscsi->credit += 1; } else { iue = cmd->iue; @@ -2965,10 +2984,7 @@ static long srp_build_response(struct sc rsp->opcode = SRP_RSP; - if (vscsi->credit > 0 && vscsi->state == SRP_PROCESSING) - rsp->req_lim_delta = cpu_to_be32(vscsi->credit); - else - rsp->req_lim_delta = cpu_to_be32(1 + vscsi->credit); + rsp->req_lim_delta = cpu_to_be32(1 + vscsi->credit); rsp->tag = cmd->rsp.tag; rsp->flags = 0;