From patchwork Mon Oct 31 05:25:52 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: 9405013 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 0AFF960588 for ; Mon, 31 Oct 2016 05:26:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F0B59290C5 for ; Mon, 31 Oct 2016 05:26:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E5339290B1; Mon, 31 Oct 2016 05:26:00 +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=-5.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, URIBL_BLACK 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 298B7290B1 for ; Mon, 31 Oct 2016 05:25:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758812AbcJaFZz (ORCPT ); Mon, 31 Oct 2016 01:25:55 -0400 Received: from mail.linux-iscsi.org ([67.23.28.174]:44469 "EHLO linux-iscsi.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758766AbcJaFZz (ORCPT ); Mon, 31 Oct 2016 01:25:55 -0400 Received: from linux-iscsi.org (localhost [127.0.0.1]) by linux-iscsi.org (Postfix) with ESMTP id 0670A40B06; Mon, 31 Oct 2016 05:26:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=linux-iscsi.org; s=default.private; t=1477891562; bh=dnHImumJL+4dVdNKrTIi/c9+HoJGk0E g8XKuVCrV8TM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To: References; b=XolLB917y1c9dO5f5qtWw4wUwMbuILCkp7dxquI2yxBfMy2+0Mfz icK9a7jDIyVmCAnmt4z+5DGDjMxs7lVeFmrvPTr/16lyebMe8YNSlFIRw6HWqUCki66 Uxpin7QiZHkj1jylTBy2MQJoxekHEVqLTCF3uleasI4tEplplcvQ= From: "Nicholas A. Bellinger" To: target-devel Cc: linux-rdma , Potnuri Bharat Teja , Steve Wise , Sagi Grimberg , Nicholas Bellinger Subject: [PATCH 1/3] target: Fix unknown fabric callback queue-full errors Date: Mon, 31 Oct 2016 05:25:52 +0000 Message-Id: <1477891554-26222-2-git-send-email-nab@linux-iscsi.org> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1477891554-26222-1-git-send-email-nab@linux-iscsi.org> References: <1477891554-26222-1-git-send-email-nab@linux-iscsi.org> Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Nicholas Bellinger This patch fixes a set of queue-full response handling bugs, where outgoing responses are leaked when a fabric driver is propagating non -EAGAIN or -ENOMEM errors to target-core. It introduces TRANSPORT_COMPLETE_QF_ERR state used to signal when CHECK_CONDITION status should be generated, when fabric driver ->write_pending(), ->queue_data_in(), or ->queue_status() callbacks fail with non -EAGAIN or -ENOMEM errors, and data-transfer should not be retried. Note all fabric driver -EAGAIN and -ENOMEM errors are still retried indefinately with associated data-transfer callbacks, following existing queue-full logic. Also fix two missing ->queue_status() queue-full cases related to CMD_T_ABORTED w/ TAS status handling. Reported-by: Potnuri Bharat Teja Cc: Potnuri Bharat Teja Reported-by: Steve Wise Cc: Steve Wise Cc: Sagi Grimberg Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 102 ++++++++++++++++++++++----------- include/target/target_core_base.h | 1 + 2 files changed, 69 insertions(+), 34 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 7dfefd6..489aa95 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -64,8 +64,9 @@ struct kmem_cache *t10_alua_lba_map_mem_cache; static void transport_complete_task_attr(struct se_cmd *cmd); +static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason); static void transport_handle_queue_full(struct se_cmd *cmd, - struct se_device *dev); + struct se_device *dev, int err, bool write_pending); static int transport_put_cmd(struct se_cmd *cmd); static void target_complete_ok_work(struct work_struct *work); @@ -811,7 +812,8 @@ void target_qf_do_work(struct work_struct *work) if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP) transport_write_pending_qf(cmd); - else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK) + else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK || + cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) transport_complete_qf(cmd); } } @@ -1720,7 +1722,7 @@ void transport_generic_request_failure(struct se_cmd *cmd, } trace_target_cmd_complete(cmd); ret = cmd->se_tfo->queue_status(cmd); - if (ret == -EAGAIN || ret == -ENOMEM) + if (ret) goto queue_full; goto check_stop; default: @@ -1731,7 +1733,7 @@ void transport_generic_request_failure(struct se_cmd *cmd, } ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0); - if (ret == -EAGAIN || ret == -ENOMEM) + if (ret) goto queue_full; check_stop: @@ -1740,8 +1742,7 @@ void transport_generic_request_failure(struct se_cmd *cmd, return; queue_full: - cmd->t_state = TRANSPORT_COMPLETE_QF_OK; - transport_handle_queue_full(cmd, cmd->se_dev); + transport_handle_queue_full(cmd, cmd->se_dev, ret, false); } EXPORT_SYMBOL(transport_generic_request_failure); @@ -1980,13 +1981,29 @@ static void transport_complete_qf(struct se_cmd *cmd) int ret = 0; transport_complete_task_attr(cmd); + /* + * If a fabric driver ->write_pending() or ->queue_data_in() callback + * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and + * the same callbacks should not be retried. Return CHECK_CONDITION + * if a scsi_status is not already set. + * + * If a fabric driver ->queue_status() has returned non zero, always + * keep retrying no matter what.. + */ + if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) { + if (cmd->scsi_status) + goto queue_status; - if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) { - trace_target_cmd_complete(cmd); - ret = cmd->se_tfo->queue_status(cmd); - goto out; + cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE; + cmd->scsi_status = SAM_STAT_CHECK_CONDITION; + cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER; + translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE); + goto queue_status; } + if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) + goto queue_status; + switch (cmd->data_direction) { case DMA_FROM_DEVICE: if (cmd->scsi_status) @@ -2010,19 +2027,33 @@ static void transport_complete_qf(struct se_cmd *cmd) break; } -out: if (ret < 0) { - transport_handle_queue_full(cmd, cmd->se_dev); + transport_handle_queue_full(cmd, cmd->se_dev, ret, false); return; } transport_lun_remove_cmd(cmd); transport_cmd_check_stop_to_fabric(cmd); } -static void transport_handle_queue_full( - struct se_cmd *cmd, - struct se_device *dev) +static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev, + int err, bool write_pending) { + /* + * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or + * ->queue_data_in() callbacks from new process context. + * + * Otherwise for other errors, transport_complete_qf() will send + * CHECK_CONDITION via ->queue_status() instead of attempting to + * retry associated fabric driver data-transfer callbacks. + */ + if (err == -EAGAIN || err == -ENOMEM) { + cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP : + TRANSPORT_COMPLETE_QF_OK; + } else { + pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err); + cmd->t_state = TRANSPORT_COMPLETE_QF_ERR; + } + spin_lock_irq(&dev->qf_cmd_lock); list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list); atomic_inc_mb(&dev->dev_qf_count); @@ -2086,7 +2117,7 @@ static void target_complete_ok_work(struct work_struct *work) WARN_ON(!cmd->scsi_status); ret = transport_send_check_condition_and_sense( cmd, 0, 1); - if (ret == -EAGAIN || ret == -ENOMEM) + if (ret) goto queue_full; transport_lun_remove_cmd(cmd); @@ -2112,7 +2143,7 @@ static void target_complete_ok_work(struct work_struct *work) } else if (rc) { ret = transport_send_check_condition_and_sense(cmd, rc, 0); - if (ret == -EAGAIN || ret == -ENOMEM) + if (ret) goto queue_full; transport_lun_remove_cmd(cmd); @@ -2137,7 +2168,7 @@ static void target_complete_ok_work(struct work_struct *work) if (target_read_prot_action(cmd)) { ret = transport_send_check_condition_and_sense(cmd, cmd->pi_err, 0); - if (ret == -EAGAIN || ret == -ENOMEM) + if (ret) goto queue_full; transport_lun_remove_cmd(cmd); @@ -2147,7 +2178,7 @@ static void target_complete_ok_work(struct work_struct *work) trace_target_cmd_complete(cmd); ret = cmd->se_tfo->queue_data_in(cmd); - if (ret == -EAGAIN || ret == -ENOMEM) + if (ret) goto queue_full; break; case DMA_TO_DEVICE: @@ -2160,7 +2191,7 @@ static void target_complete_ok_work(struct work_struct *work) atomic_long_add(cmd->data_length, &cmd->se_lun->lun_stats.tx_data_octets); ret = cmd->se_tfo->queue_data_in(cmd); - if (ret == -EAGAIN || ret == -ENOMEM) + if (ret) goto queue_full; break; } @@ -2169,7 +2200,7 @@ static void target_complete_ok_work(struct work_struct *work) queue_status: trace_target_cmd_complete(cmd); ret = cmd->se_tfo->queue_status(cmd); - if (ret == -EAGAIN || ret == -ENOMEM) + if (ret) goto queue_full; break; default: @@ -2183,8 +2214,8 @@ static void target_complete_ok_work(struct work_struct *work) queue_full: pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p," " data_direction: %d\n", cmd, cmd->data_direction); - cmd->t_state = TRANSPORT_COMPLETE_QF_OK; - transport_handle_queue_full(cmd, cmd->se_dev); + + transport_handle_queue_full(cmd, cmd->se_dev, ret, false); } void target_free_sgl(struct scatterlist *sgl, int nents) @@ -2434,18 +2465,14 @@ void transport_kunmap_data_sg(struct se_cmd *cmd) transport_cmd_check_stop(cmd, false, true); ret = cmd->se_tfo->write_pending(cmd); - if (ret == -EAGAIN || ret == -ENOMEM) + if (ret) goto queue_full; - /* fabric drivers should only return -EAGAIN or -ENOMEM as error */ - WARN_ON(ret); - - return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; + return 0; queue_full: pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd); - cmd->t_state = TRANSPORT_COMPLETE_QF_WP; - transport_handle_queue_full(cmd, cmd->se_dev); + transport_handle_queue_full(cmd, cmd->se_dev, ret, true); return 0; } EXPORT_SYMBOL(transport_generic_new_cmd); @@ -2455,10 +2482,10 @@ static void transport_write_pending_qf(struct se_cmd *cmd) int ret; ret = cmd->se_tfo->write_pending(cmd); - if (ret == -EAGAIN || ret == -ENOMEM) { + if (ret) { pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd); - transport_handle_queue_full(cmd, cmd->se_dev); + transport_handle_queue_full(cmd, cmd->se_dev, ret, true); } } @@ -2951,6 +2978,8 @@ static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status) __releases(&cmd->t_state_lock) __acquires(&cmd->t_state_lock) { + int ret; + assert_spin_locked(&cmd->t_state_lock); WARN_ON_ONCE(!irqs_disabled()); @@ -2974,7 +3003,9 @@ static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status) trace_target_cmd_complete(cmd); spin_unlock_irq(&cmd->t_state_lock); - cmd->se_tfo->queue_status(cmd); + ret = cmd->se_tfo->queue_status(cmd); + if (ret) + transport_handle_queue_full(cmd, cmd->se_dev, ret, false); spin_lock_irq(&cmd->t_state_lock); return 1; @@ -2995,6 +3026,7 @@ int transport_check_aborted_status(struct se_cmd *cmd, int send_status) void transport_send_task_abort(struct se_cmd *cmd) { unsigned long flags; + int ret; spin_lock_irqsave(&cmd->t_state_lock, flags); if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) { @@ -3030,7 +3062,9 @@ void transport_send_task_abort(struct se_cmd *cmd) cmd->t_task_cdb[0], cmd->tag); trace_target_cmd_complete(cmd); - cmd->se_tfo->queue_status(cmd); + ret = cmd->se_tfo->queue_status(cmd); + if (ret) + transport_handle_queue_full(cmd, cmd->se_dev, ret, false); } static void target_tmr_work(struct work_struct *work) diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index c211900..6a5e439 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -119,6 +119,7 @@ enum transport_state_table { TRANSPORT_ISTATE_PROCESSING = 11, TRANSPORT_COMPLETE_QF_WP = 18, TRANSPORT_COMPLETE_QF_OK = 19, + TRANSPORT_COMPLETE_QF_ERR = 20, }; /* Used for struct se_cmd->se_cmd_flags */