From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934047AbbIVSHf (ORCPT ); Tue, 22 Sep 2015 14:07:35 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42941 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933517AbbIVRyB (ORCPT ); Tue, 22 Sep 2015 13:54:01 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Hiral Shah , Sesidhar Baddela , Anil Chintalapati , James Bottomley , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 071/102] fnic: Use the local variable instead of I/O flag to acquire io_req_lock in fnic_queuecommand() to avoid deadloack Date: Tue, 22 Sep 2015 10:52:07 -0700 Message-Id: <1442944358-1248-72-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1442944358-1248-1-git-send-email-kamal@canonical.com> References: <1442944358-1248-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt7 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Hiral Shah commit db196935d9562abec4510f48d887bc1f1e054fcf upstream. We added changes in fnic driver patch 1.6.0.16 to acquire io_req_lock in fnic_queuecommand() before issuing I/O so that io completion is serialized. But when releasing the lock we check for the I/O flag and this could be modified if IO abort occurs before I/O completion. In this case we wont release the lock and causes deadlock in some scenerios. Using the local variable to check the IO lock status will resolve the problem. Fixes: 41df7b02db82cf6c14f094757bac3830d10a827f Signed-off-by: Hiral Shah Signed-off-by: Sesidhar Baddela Signed-off-by: Anil Chintalapati Reviewed-by: Martin K. Petersen Signed-off-by: James Bottomley Signed-off-by: Kamal Mostafa --- drivers/scsi/fnic/fnic.h | 2 +- drivers/scsi/fnic/fnic_scsi.c | 4 +++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/fnic/fnic.h b/drivers/scsi/fnic/fnic.h index 26270c3..ce129e5 100644 --- a/drivers/scsi/fnic/fnic.h +++ b/drivers/scsi/fnic/fnic.h @@ -39,7 +39,7 @@ #define DRV_NAME "fnic" #define DRV_DESCRIPTION "Cisco FCoE HBA Driver" -#define DRV_VERSION "1.6.0.17" +#define DRV_VERSION "1.6.0.17a" #define PFX DRV_NAME ": " #define DFX DRV_NAME "%d: " diff --git a/drivers/scsi/fnic/fnic_scsi.c b/drivers/scsi/fnic/fnic_scsi.c index 155b286..25436cd 100644 --- a/drivers/scsi/fnic/fnic_scsi.c +++ b/drivers/scsi/fnic/fnic_scsi.c @@ -425,6 +425,7 @@ static int fnic_queuecommand_lck(struct scsi_cmnd *sc, void (*done)(struct scsi_ unsigned long ptr; struct fc_rport_priv *rdata; spinlock_t *io_lock = NULL; + int io_lock_acquired = 0; if (unlikely(fnic_chk_state_flags_locked(fnic, FNIC_FLAGS_IO_BLOCKED))) return SCSI_MLQUEUE_HOST_BUSY; @@ -518,6 +519,7 @@ static int fnic_queuecommand_lck(struct scsi_cmnd *sc, void (*done)(struct scsi_ spin_lock_irqsave(io_lock, flags); /* initialize rest of io_req */ + io_lock_acquired = 1; io_req->port_id = rport->port_id; io_req->start_time = jiffies; CMD_STATE(sc) = FNIC_IOREQ_CMD_PENDING; @@ -571,7 +573,7 @@ out: (((u64)CMD_FLAGS(sc) >> 32) | CMD_STATE(sc))); /* if only we issued IO, will we have the io lock */ - if (CMD_FLAGS(sc) & FNIC_IO_INITIALIZED) + if (io_lock_acquired) spin_unlock_irqrestore(io_lock, flags); atomic_dec(&fnic->in_flight); -- 1.9.1