From patchwork Thu Feb 22 19:30:20 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 10236213 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 0001D60209 for ; Thu, 22 Feb 2018 19:30:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EFCBA28D2E for ; Thu, 22 Feb 2018 19:30:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E418A28D4D; Thu, 22 Feb 2018 19:30:25 +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 B391828D2E for ; Thu, 22 Feb 2018 19:30:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751378AbeBVTaW (ORCPT ); Thu, 22 Feb 2018 14:30:22 -0500 Received: from esa3.hgst.iphmx.com ([216.71.153.141]:47803 "EHLO esa3.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750821AbeBVTaV (ORCPT ); Thu, 22 Feb 2018 14:30:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1519327822; x=1550863822; h=from:to:cc:subject:date:message-id; bh=o9K6w4S78Sa+3Yv/rPt4otq19tBQFLKeMow9b8GCh3E=; b=q4r3TQm4yPJka4JtOb7P3KNIO8kD2SYjXVEkkbmHvKMeggcRTUcmZM0d 3ljfnGhQHJEUCjLiKYxC5UqIjy7eOIvbwayHQ7WQ6LouyjYxUA7t0ChaK 2yXs2pc73a2k8oj+1jnsC8wC9LJGYF+EOnHsCsEXkibsxsrNVv/RlAuZ6 YKZ/Cc4qA6r6pHEDJVSW71adfCPocy8WOgt+SGze5476MTvPQINB8zgTN KTzOqrofcysgI9XSt84zvd2vgChz0BpUvW35WgUQk/ZlK+k/ZE57vi8ZD HHwzB7lu1II39PU4hFrU3LLr/V7Kg+dM8ELbGvVmVyv2bQSkb7ISZf+kt g==; X-IronPort-AV: E=Sophos;i="5.47,378,1515427200"; d="scan'208";a="72555712" Received: from uls-op-cesaip02.wdc.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 23 Feb 2018 03:30:21 +0800 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep02.wdc.com with ESMTP; 22 Feb 2018 11:24:01 -0800 Received: from thinkpad-bart.sdcorp.global.sandisk.com (HELO thinkpad-bart.int.fusionio.com) ([10.11.171.236]) by uls-op-cesaip02.wdc.com with ESMTP; 22 Feb 2018 11:30:20 -0800 From: Bart Van Assche To: "Martin K . Petersen" , "James E . J . Bottomley" Cc: linux-scsi@vger.kernel.org, Bart Van Assche , Natanael Copa , Damien Le Moal , Alexandre Oliva , Pavel Tikhomirov , Hannes Reinecke , Johannes Thumshirn , stable@vger.kernel.org Subject: [PATCH v2] Avoid that ATA error handling can trigger a kernel hang or oops Date: Thu, 22 Feb 2018 11:30:20 -0800 Message-Id: <20180222193020.30276-1-bart.vanassche@wdc.com> X-Mailer: git-send-email 2.16.2 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 Avoid that the recently introduced call_rcu() call in the SCSI core triggers a double call_rcu() call. Reported-by: Natanael Copa Reported-by: Damien Le Moal References: https://bugzilla.kernel.org/show_bug.cgi?id=198861 Fixes: 3bd6f43f5cb3 ("scsi: core: Ensure that the SCSI error handler gets woken up") Signed-off-by: Bart Van Assche Cc: Natanael Copa Cc: Damien Le Moal Cc: Alexandre Oliva Cc: Pavel Tikhomirov Cc: Hannes Reinecke Cc: Johannes Thumshirn Cc: Reviewed-by: Damien Le Moal Tested-by: Damien Le Moal --- drivers/scsi/hosts.c | 3 --- drivers/scsi/scsi_error.c | 5 +++-- drivers/scsi/scsi_lib.c | 2 ++ include/scsi/scsi_cmnd.h | 3 +++ include/scsi/scsi_host.h | 2 -- 5 files changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index a0a7e4ff255c..7279d3d2e941 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -334,8 +334,6 @@ static void scsi_host_dev_release(struct device *dev) if (shost->work_q) destroy_workqueue(shost->work_q); - destroy_rcu_head(&shost->rcu); - if (shost->shost_state == SHOST_CREATED) { /* * Free the shost_dev device name here if scsi_host_alloc() @@ -404,7 +402,6 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) INIT_LIST_HEAD(&shost->starved_list); init_waitqueue_head(&shost->host_wait); mutex_init(&shost->scan_mutex); - init_rcu_head(&shost->rcu); index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL); if (index < 0) diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 96f988a7efda..9b0242f84407 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -229,7 +229,8 @@ static void scsi_eh_reset(struct scsi_cmnd *scmd) static void scsi_eh_inc_host_failed(struct rcu_head *head) { - struct Scsi_Host *shost = container_of(head, typeof(*shost), rcu); + struct scsi_cmnd *scmd = container_of(head, typeof(*scmd), rcu); + struct Scsi_Host *shost = scmd->device->host; unsigned long flags; spin_lock_irqsave(shost->host_lock, flags); @@ -265,7 +266,7 @@ void scsi_eh_scmd_add(struct scsi_cmnd *scmd) * Ensure that all tasks observe the host state change before the * host_failed change. */ - call_rcu(&shost->rcu, scsi_eh_inc_host_failed); + call_rcu(&scmd->rcu, scsi_eh_inc_host_failed); } /** diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index aea5a1ae318b..e1ca2160aa40 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -671,6 +671,7 @@ static bool scsi_end_request(struct request *req, blk_status_t error, if (!blk_rq_is_scsi(req)) { WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED)); cmd->flags &= ~SCMD_INITIALIZED; + destroy_rcu_head(&cmd->rcu); } if (req->mq_ctx) { @@ -1151,6 +1152,7 @@ static void scsi_initialize_rq(struct request *rq) struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); scsi_req_init(&cmd->req); + init_rcu_head(&cmd->rcu); cmd->jiffies_at_alloc = jiffies; cmd->retries = 0; } diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index d8d4a902a88d..2280b2351739 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -68,6 +68,9 @@ struct scsi_cmnd { struct list_head list; /* scsi_cmnd participates in queue lists */ struct list_head eh_entry; /* entry for the host eh_cmd_q */ struct delayed_work abort_work; + + struct rcu_head rcu; + int eh_eflags; /* Used by error handlr */ /* diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 19317585ae48..7aedb6776b4f 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -577,8 +577,6 @@ struct Scsi_Host { struct blk_mq_tag_set tag_set; }; - struct rcu_head rcu; - atomic_t host_busy; /* commands actually active on low-level */ atomic_t host_blocked;