From patchwork Tue Jun 7 04:12:26 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Nicholas A. Bellinger" X-Patchwork-Id: 9159827 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A721160467 for ; Tue, 7 Jun 2016 04:14:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9A03C26861 for ; Tue, 7 Jun 2016 04:14:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8DC7C2834A; Tue, 7 Jun 2016 04:14:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E87C226861 for ; Tue, 7 Jun 2016 04:14:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753123AbcFGEOL (ORCPT ); Tue, 7 Jun 2016 00:14:11 -0400 Received: from mail.linux-iscsi.org ([67.23.28.174]:55943 "EHLO linux-iscsi.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753110AbcFGENh (ORCPT ); Tue, 7 Jun 2016 00:13:37 -0400 Received: from linux-iscsi.org (localhost [127.0.0.1]) by linux-iscsi.org (Postfix) with ESMTP id CE7B222CAAB; Tue, 7 Jun 2016 04:12:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=linux-iscsi.org; s=default.private; t=1465272764; bh=oDxuzgQr8BYTT7U1l4iOwNK+DTEpPBh XMs7IlloITb4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To: References; b=I8duuHFFNcLpGWe02rcQy2c7Asrln8OHucpO+rnOFhN3XACmwpuJ 6mkes5AzhKUpWD6pzBpLlL0P5H/3fPweq+IZg3+JYu3tHf+uCB+K7IbNAjlkoURA+ZD RjuswXJoGahrdz8ABhd9F9jAfPIP9N1xXsih7vBFr43eDYp2TEJw= From: "Nicholas A. Bellinger" To: target-devel Cc: linux-scsi , Jens Axboe , Christoph Hellwig , Martin Petersen , Sagi Grimberg , Hannes Reinecke , Mike Christie , Dave B Minturn , Nicholas Bellinger Subject: [PATCH-v2 01/16] target: Fix for hang of Ordered task in TCM Date: Tue, 7 Jun 2016 04:12:26 +0000 Message-Id: <1465272761-26045-2-git-send-email-nab@linux-iscsi.org> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1465272761-26045-1-git-send-email-nab@linux-iscsi.org> References: <1465272761-26045-1-git-send-email-nab@linux-iscsi.org> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Nicholas Bellinger If a command with a Simple task attribute is failed due to a Unit Attention, then a subsequent command with an Ordered task attribute will hang forever. The reason for this is that the Unit Attention status is checked for in target_setup_cmd_from_cdb, before the call to target_execute_cmd, which calls target_handle_task_attr, which in turn increments dev->simple_cmds. However, transport_generic_request_failure still calls transport_complete_task_attr, which will decrement dev->simple_cmds. In this case, simple_cmds is now -1. So when a command with the Ordered task attribute is sent, target_handle_task_attr sees that dev->simple_cmds is not 0, so it decides it can't execute the command until all the (nonexistent) Simple commands have completed. Reported-by: Michael Cyr Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_internal.h | 1 + drivers/target/target_core_sbc.c | 2 +- drivers/target/target_core_transport.c | 45 ++++++++++++++++++++++++++-------- include/target/target_core_fabric.h | 1 - 4 files changed, 37 insertions(+), 12 deletions(-) diff --git a/drivers/target/target_core_internal.h b/drivers/target/target_core_internal.h index fc91e85..e2c970a 100644 --- a/drivers/target/target_core_internal.h +++ b/drivers/target/target_core_internal.h @@ -146,6 +146,7 @@ sense_reason_t target_cmd_size_check(struct se_cmd *cmd, unsigned int size); void target_qf_do_work(struct work_struct *work); bool target_check_wce(struct se_device *dev); bool target_check_fua(struct se_device *dev); +void __target_execute_cmd(struct se_cmd *, bool); /* target_core_stat.c */ void target_stat_setup_dev_default_groups(struct se_device *); diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index a9057aa..04f616b 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -602,7 +602,7 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool succes cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT; spin_unlock_irq(&cmd->t_state_lock); - __target_execute_cmd(cmd); + __target_execute_cmd(cmd, false); kfree(buf); return ret; diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 5ab3967..614ef3f 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1761,20 +1761,45 @@ queue_full: } EXPORT_SYMBOL(transport_generic_request_failure); -void __target_execute_cmd(struct se_cmd *cmd) +void __target_execute_cmd(struct se_cmd *cmd, bool do_checks) { sense_reason_t ret; - if (cmd->execute_cmd) { - ret = cmd->execute_cmd(cmd); - if (ret) { - spin_lock_irq(&cmd->t_state_lock); - cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT); - spin_unlock_irq(&cmd->t_state_lock); + if (!cmd->execute_cmd) { + ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + goto err; + } + if (do_checks) { + /* + * Check for an existing UNIT ATTENTION condition after + * target_handle_task_attr() has done SAM task attr + * checking, and possibly have already defered execution + * out to target_restart_delayed_cmds() context. + */ + ret = target_scsi3_ua_check(cmd); + if (ret) + goto err; - transport_generic_request_failure(cmd, ret); + ret = target_alua_state_check(cmd); + if (ret) + goto err; + + ret = target_check_reservation(cmd); + if (ret) { + cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT; + goto err; } } + + ret = cmd->execute_cmd(cmd); + if (!ret) + return; +err: + spin_lock_irq(&cmd->t_state_lock); + cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT); + spin_unlock_irq(&cmd->t_state_lock); + + transport_generic_request_failure(cmd, ret); } static int target_write_prot_action(struct se_cmd *cmd) @@ -1899,7 +1924,7 @@ void target_execute_cmd(struct se_cmd *cmd) return; } - __target_execute_cmd(cmd); + __target_execute_cmd(cmd, true); } EXPORT_SYMBOL(target_execute_cmd); @@ -1923,7 +1948,7 @@ static void target_restart_delayed_cmds(struct se_device *dev) list_del(&cmd->se_delayed_node); spin_unlock(&dev->delayed_cmd_lock); - __target_execute_cmd(cmd); + __target_execute_cmd(cmd, true); if (cmd->sam_task_attr == TCM_ORDERED_TAG) break; diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h index de44462..5cd6faa 100644 --- a/include/target/target_core_fabric.h +++ b/include/target/target_core_fabric.h @@ -163,7 +163,6 @@ int core_tmr_alloc_req(struct se_cmd *, void *, u8, gfp_t); void core_tmr_release_req(struct se_tmr_req *); int transport_generic_handle_tmr(struct se_cmd *); void transport_generic_request_failure(struct se_cmd *, sense_reason_t); -void __target_execute_cmd(struct se_cmd *); int transport_lookup_tmr_lun(struct se_cmd *, u64); void core_allocate_nexus_loss_ua(struct se_node_acl *acl);