Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753638Ab3HVFKi (ORCPT ); Thu, 22 Aug 2013 01:10:38 -0400 Received: from mail-ob0-f171.google.com ([209.85.214.171]:47916 "EHLO mail-ob0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753613Ab3HVFKb (ORCPT ); Thu, 22 Aug 2013 01:10:31 -0400 From: "Nicholas A. Bellinger" To: target-devel Cc: lkml , linux-scsi , Christoph Hellwig , Hannes Reinecke , Martin Petersen , Chris Mason , Roland Dreier , James Bottomley , Nicholas Bellinger , Nicholas Bellinger Subject: [PATCH-v2 12/12] target: Release COMPARE_AND_WRITE mutex in generic failure path Date: Thu, 22 Aug 2013 04:54:10 +0000 Message-Id: <1377147250-10125-13-git-send-email-nab@daterainc.com> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1377147250-10125-1-git-send-email-nab@daterainc.com> References: <1377147250-10125-1-git-send-email-nab@daterainc.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2646 Lines: 69 From: Nicholas Bellinger This patch adds a extra check for SCF_COMPARE_AND_WRITE within transport_generic_request_failure() to invoke the callback for compare_and_write_callback() or compare_and_write_done(), in order to release se_dev->caw_mutex from the generic failure path. It also adds to checks within compare_and_write_callback() to avoid processing when transport_generic_request_failure() occurs early enough that cmd->t_data_sg or cmd->t_bidi_data_sg have not been setup yet, nor se_dev->caw_mutex obtained from within sbc_compare_and_write(). Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Martin Petersen Cc: Chris Mason Cc: James Bottomley Cc: Nicholas Bellinger Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_sbc.c | 7 +++++++ drivers/target/target_core_transport.c | 6 ++++++ 2 files changed, 13 insertions(+), 0 deletions(-) diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index bb1b42b..287e960 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -372,6 +372,13 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd) sense_reason_t ret = TCM_NO_SENSE; int rc, i; + /* + * Handle early failure in transport_generic_request_failure(), + * which will not have taken ->caw_mutex yet.. + */ + if (!cmd->t_data_sg || !cmd->t_bidi_data_sg) + return TCM_NO_SENSE; + buf = kzalloc(cmd->data_length, GFP_KERNEL); if (!buf) { pr_err("Unable to allocate compare_and_write buf\n"); diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index a95e799..3009cda 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1560,6 +1560,12 @@ void transport_generic_request_failure(struct se_cmd *cmd, * For SAM Task Attribute emulation for failed struct se_cmd */ transport_complete_task_attr(cmd); + /* + * Handle special case for COMPARE_AND_WRITE failure, where the + * callback is expected to drop the per device ->caw_mutex. + */ + if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) + cmd->transport_complete_callback(cmd); switch (sense_reason) { case TCM_NON_EXISTENT_LUN: -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/