From patchwork Mon Jan 22 06:25:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: chenxiang X-Patchwork-Id: 766787 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B51C5C96 for ; Mon, 22 Jan 2024 06:21:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705904471; cv=none; b=TSk1pIQRN5l8zlEfqlMy621zmVkq0e7jA8f5UQ2eLt+x4da/HjBdmjVPVew71fQpFltoIYa+XBl+mYL/aZ64vGcaADQN8VRHMzR0pd31dEaVSnuNgnwmO9niQh5THp9zuTyN2JpL/XJwnw+waRFAlO7AHEPmXRZ8hgAE1fh3MiI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705904471; c=relaxed/simple; bh=xw17tTBVt3kJfbobrnAghRfhOrVBDekhpneQng7RV14=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CIV8YJoL2jdhwStOzpFYRQF2LeTALBEGJSKw0lwBcMmaq1BkntjV7rzuEgT8xy0Pj9aPYoe+bSyYA93a4OuwvWp63ji1xgIttKdIVRXjChaFQmbbYKcJ3zrnKAJEqjEYPWD9xVUe53MegQiyr7ZSLcFu7sjGagIgbppMH7fMmaU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hisilicon.com; spf=pass smtp.mailfrom=hisilicon.com; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hisilicon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=hisilicon.com Received: from mail.maildlp.com (unknown [172.19.162.254]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4TJKnw6WKhzsWKD; Mon, 22 Jan 2024 14:20:04 +0800 (CST) Received: from kwepemi500025.china.huawei.com (unknown [7.221.188.170]) by mail.maildlp.com (Postfix) with ESMTPS id E1CEA18007B; Mon, 22 Jan 2024 14:20:49 +0800 (CST) Received: from localhost.localdomain (10.69.192.58) by kwepemi500025.china.huawei.com (7.221.188.170) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Mon, 22 Jan 2024 14:20:49 +0800 From: chenxiang To: , CC: , , Yihang Li , Xiang Chen Subject: [PATCH 1/4] scsi: hisi_sas: Fix a deadlock issue related to automatic dump Date: Mon, 22 Jan 2024 14:25:44 +0800 Message-ID: <1705904747-62186-2-git-send-email-chenxiang66@hisilicon.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1705904747-62186-1-git-send-email-chenxiang66@hisilicon.com> References: <1705904747-62186-1-git-send-email-chenxiang66@hisilicon.com> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemi500025.china.huawei.com (7.221.188.170) From: Yihang Li If we issue a disabling PHY command, the device attached with it will go offline, if a 2 bit ECC error occurs at the same time, a hung task may be found: [ 4613.652388] INFO: task kworker/u256:0:165233 blocked for more than 120 seconds. [ 4613.666297] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4613.674809] task:kworker/u256:0 state:D stack: 0 pid:165233 ppid: 2 flags:0x00000208 [ 4613.683959] Workqueue: 0000:74:02.0_disco_q sas_revalidate_domain [libsas] [ 4613.691518] Call trace: [ 4613.694678] __switch_to+0xf8/0x17c [ 4613.698872] __schedule+0x660/0xee0 [ 4613.703063] schedule+0xac/0x240 [ 4613.706994] schedule_timeout+0x500/0x610 [ 4613.711705] __down+0x128/0x36c [ 4613.715548] down+0x240/0x2d0 [ 4613.719221] hisi_sas_internal_abort_timeout+0x1bc/0x260 [hisi_sas_main] [ 4613.726618] sas_execute_internal_abort+0x144/0x310 [libsas] [ 4613.732976] sas_execute_internal_abort_dev+0x44/0x60 [libsas] [ 4613.739504] hisi_sas_internal_task_abort_dev.isra.0+0xbc/0x1b0 [hisi_sas_main] [ 4613.747499] hisi_sas_dev_gone+0x174/0x250 [hisi_sas_main] [ 4613.753682] sas_notify_lldd_dev_gone+0xec/0x2e0 [libsas] [ 4613.759781] sas_unregister_common_dev+0x4c/0x7a0 [libsas] [ 4613.765962] sas_destruct_devices+0xb8/0x120 [libsas] [ 4613.771709] sas_do_revalidate_domain.constprop.0+0x1b8/0x31c [libsas] [ 4613.778930] sas_revalidate_domain+0x60/0xa4 [libsas] [ 4613.784716] process_one_work+0x248/0x950 [ 4613.789424] worker_thread+0x318/0x934 [ 4613.793878] kthread+0x190/0x200 [ 4613.797810] ret_from_fork+0x10/0x18 [ 4613.802121] INFO: task kworker/u256:4:316722 blocked for more than 120 seconds. [ 4613.816026] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4613.824538] task:kworker/u256:4 state:D stack: 0 pid:316722 ppid: 2 flags:0x00000208 [ 4613.833670] Workqueue: 0000:74:02.0 hisi_sas_rst_work_handler [hisi_sas_main] [ 4613.841491] Call trace: [ 4613.844647] __switch_to+0xf8/0x17c [ 4613.848852] __schedule+0x660/0xee0 [ 4613.853052] schedule+0xac/0x240 [ 4613.856984] schedule_timeout+0x500/0x610 [ 4613.861695] __down+0x128/0x36c [ 4613.865542] down+0x240/0x2d0 [ 4613.869216] hisi_sas_controller_prereset+0x58/0x1fc [hisi_sas_main] [ 4613.876324] hisi_sas_rst_work_handler+0x40/0x8c [hisi_sas_main] [ 4613.883019] process_one_work+0x248/0x950 [ 4613.887732] worker_thread+0x318/0x934 [ 4613.892204] kthread+0x190/0x200 [ 4613.896118] ret_from_fork+0x10/0x18 [ 4613.900423] INFO: task kworker/u256:1:348985 blocked for more than 121 seconds. [ 4613.914341] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4613.922852] task:kworker/u256:1 state:D stack: 0 pid:348985 ppid: 2 flags:0x00000208 [ 4613.931984] Workqueue: 0000:74:02.0_event_q sas_port_event_worker [libsas] [ 4613.939549] Call trace: [ 4613.942702] __switch_to+0xf8/0x17c [ 4613.946892] __schedule+0x660/0xee0 [ 4613.951083] schedule+0xac/0x240 [ 4613.955015] schedule_timeout+0x500/0x610 [ 4613.959725] wait_for_common+0x200/0x610 [ 4613.964349] wait_for_completion+0x3c/0x5c [ 4613.969146] flush_workqueue+0x198/0x790 [ 4613.973776] sas_porte_broadcast_rcvd+0x1e8/0x320 [libsas] [ 4613.979960] sas_port_event_worker+0x54/0xa0 [libsas] [ 4613.985708] process_one_work+0x248/0x950 [ 4613.990420] worker_thread+0x318/0x934 [ 4613.994868] kthread+0x190/0x200 [ 4613.998800] ret_from_fork+0x10/0x18 This is because when the device goes offline, we obtain the hisi_hba semaphore and send the ABORT_DEV command to the device. However, the internal abort timed out due to the 2 bit ECC error and triggers automatic dump. In addition, since the hisi_hba semaphore has been obtained, the dump cannot be executed and the controller cannot be reset. Therefore, the deadlocks occur on the following circular dependencies: hisi_sas_dev_gone() -> down() -> hisi_sas_internal_task_abort_dev() -> ... -> hisi_sas_internal_abort_timeout() -> down(). The deadlock is triggered only when the timeout occurs during device goes offline. To fix this issue, use .rst_ha_timeout to distinguish the scenario where a device goes offline from other scenarios. Fixes: 2ff07b5c6fe9 ("scsi: hisi_sas: Directly call register snapshot instead of using workqueue") Signed-off-by: Yihang Li Signed-off-by: Xiang Chen --- drivers/scsi/hisi_sas/hisi_sas_main.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c index bbb7b2d..1abc62b 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_main.c +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c @@ -1962,9 +1962,17 @@ static bool hisi_sas_internal_abort_timeout(struct sas_task *task, struct hisi_sas_internal_abort_data *timeout = data; if (hisi_sas_debugfs_enable && hisi_hba->debugfs_itct[0].itct) { - down(&hisi_hba->sem); + /* + * If timeout occurs in device gone scenario, to avoid + * circular dependency like: + * hisi_sas_dev_gone() -> down() -> ... -> + * hisi_sas_internal_abort_timeout() -> down(). + */ + if (!timeout->rst_ha_timeout) + down(&hisi_hba->sem); hisi_hba->hw->debugfs_snapshot_regs(hisi_hba); - up(&hisi_hba->sem); + if (!timeout->rst_ha_timeout) + up(&hisi_hba->sem); } if (task->task_state_flags & SAS_TASK_STATE_DONE) {