From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752590AbdKHEbT (ORCPT ); Tue, 7 Nov 2017 23:31:19 -0500 Received: from mail.linux-iscsi.org ([67.23.28.174]:60309 "EHLO linux-iscsi.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752195AbdKHEbL (ORCPT ); Tue, 7 Nov 2017 23:31:11 -0500 From: "Nicholas A. Bellinger" To: target-devel Cc: linux-scsi , lkml , Nicholas Bellinger , Mike Christie , Hannes Reinecke , "Bryant G. Ly" , Michael Cyr , Potnuri Bharat Teja , Sagi Grimberg Subject: [PATCH 3/6] target: Fix quiese during transport_write_pending_qf endless loop Date: Wed, 8 Nov 2017 04:31:49 +0000 Message-Id: <1510115512-15617-4-git-send-email-nab@linux-iscsi.org> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1510115512-15617-1-git-send-email-nab@linux-iscsi.org> References: <1510115512-15617-1-git-send-email-nab@linux-iscsi.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicholas Bellinger This patch fixes a potential end-less loop during QUEUE_FULL, where cmd->se_tfo->write_pending() callback fails repeatedly but __transport_wait_for_tasks() has already been invoked to quiese the outstanding se_cmd descriptor. To address this bug, this patch adds a CMD_T_STOP|CMD_T_ABORTED check within transport_write_pending_qf() and invokes the existing se_cmd->t_transport_stop_comp to signal quiese completion back to __transport_wait_for_tasks(). Cc: Mike Christie Cc: Hannes Reinecke Cc: Bryant G. Ly Cc: Michael Cyr Cc: Potnuri Bharat Teja Cc: Sagi Grimberg Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index d02218c..0e89db8 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -2560,7 +2560,20 @@ void transport_kunmap_data_sg(struct se_cmd *cmd) static void transport_write_pending_qf(struct se_cmd *cmd) { + unsigned long flags; int ret; + bool stop; + + spin_lock_irqsave(&cmd->t_state_lock, flags); + stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED)); + spin_unlock_irqrestore(&cmd->t_state_lock, flags); + + if (stop) { + pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n", + __func__, __LINE__, cmd->tag); + complete_all(&cmd->t_transport_stop_comp); + return; + } ret = cmd->se_tfo->write_pending(cmd); if (ret) { -- 1.9.1