From patchwork Mon Sep 7 15:47:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomas Henzl X-Patchwork-Id: 296836 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8410DC43461 for ; Mon, 7 Sep 2020 15:49:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4BED721473 for ; Mon, 7 Sep 2020 15:49:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MFbJaNqj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730235AbgIGPsA (ORCPT ); Mon, 7 Sep 2020 11:48:00 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:48490 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730107AbgIGPrw (ORCPT ); Mon, 7 Sep 2020 11:47:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599493669; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=j5sybpypzHTEbaKxUL08ltwwNgxe7hLOJsUxK8gZhcA=; b=MFbJaNqj2hzGp20sjfAn6nzKv9Xiu1vRMuIUT+M2YugcAleylIrJghMj5VFQtvPcKu5/ks ilLzDXnpYqWvh0NI394XtFO1G/lJh2nuY7ru9jzhHxhFRzb0U0g6CND1myipZDMhCvt2Jd Bm7/eGxx9oFsS4IXQ//SAvuLSr5gqjo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-274-qPhm_QpDOl2zvuoLxkU0CQ-1; Mon, 07 Sep 2020 11:47:47 -0400 X-MC-Unique: qPhm_QpDOl2zvuoLxkU0CQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E9B5C801ADF for ; Mon, 7 Sep 2020 15:47:46 +0000 (UTC) Received: from localhost.localdomain.com (unknown [10.40.194.205]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6ADD45D9D2 for ; Mon, 7 Sep 2020 15:47:46 +0000 (UTC) From: Tomas Henzl To: linux-scsi@vger.kernel.org Subject: [PATCH] scsi: take module reference during async scan Date: Mon, 7 Sep 2020 17:47:45 +0200 Message-Id: <20200907154745.20145-1-thenzl@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org During an async scan the driver shost->hostt structures are used, that may cause issues when the driver is removed at that time. As protection take the module reference. Signed-off-by: Tomas Henzl --- drivers/scsi/scsi_scan.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index f2437a757..c9cc0862c 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -1825,6 +1825,8 @@ static void do_scan_async(void *_data, async_cookie_t c) do_scsi_scan_host(shost); scsi_finish_async_scan(data); + + module_put(shost->hostt->module); } /** @@ -1848,6 +1850,12 @@ void scsi_scan_host(struct Scsi_Host *shost) return; } + /* protection against surprise driver removal + * module_put is called from do_scan_async + */ + if (!try_module_get(shost->hostt->module)) + return; + /* register with the async subsystem so wait_for_device_probe() * will flush this work */