From patchwork Sun Aug 30 06:24:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 296945 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=-12.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 D7BF2C433E7 for ; Sun, 30 Aug 2020 06:27:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B31072083E for ; Sun, 30 Aug 2020 06:27:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Y4MW8JNe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728852AbgH3G1Q (ORCPT ); Sun, 30 Aug 2020 02:27:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726490AbgH3GZB (ORCPT ); Sun, 30 Aug 2020 02:25:01 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EAECFC06123D; Sat, 29 Aug 2020 23:25:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=fsJnsxp6Lv7GfuelQJCt9no0qZxkObiCeO/OIGyJg2A=; b=Y4MW8JNegekNwPJzEBHhT3K3A7 DjIC4K8m2vXIBxYWeevEtlhDZtG8rTEmYtUVEdqBzFabBQfsqHqtwJMw4GRD8xdPMTLq65hM6hu8z /WJ8vWhqoX33BTzBgy2Tae/Yke6qqLnvINzdUngQFnS48iasVU7nUv1TMM2sAJsynR422C+V3Dcet Jj9CBQ4VxWPBuvKpMwAJ83qNlKPYXIi8+SzzV23pqZntpBdiWVOYgZwm5J+u4g/aVWm/ERqzuoOYM PO2i9X0WpWw6q0ht6vWt5s9/80jf50+L4QDfNs2ayFiFy4W9rcb5s77ChsmWTzaBWH0nHGjwqThgP cWhlxTvA==; Received: from [2001:4bb8:18c:45ba:9892:9e86:5202:32f0] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kCGlr-0002NK-BV; Sun, 30 Aug 2020 06:24:55 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Denis Efremov , "David S. Miller" , Song Liu , Al Viro , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, linux-raid@vger.kernel.org, linux-scsi@vger.kernel.org, linux-m68k@lists.linux-m68k.org Subject: [PATCH 09/19] sd: use __register_blkdev to avoid a modprobe for an unregistered dev_t Date: Sun, 30 Aug 2020 08:24:35 +0200 Message-Id: <20200830062445.1199128-10-hch@lst.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200830062445.1199128-1-hch@lst.de> References: <20200830062445.1199128-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Switch from using blk_register_region to the probe callback passed to __register_blkdev to disable the request_module call for an unclaimed dev_t in the SD majors. Signed-off-by: Christoph Hellwig --- drivers/scsi/sd.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 95018e650f2d0c..ece87b1aab1b78 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -596,13 +596,11 @@ static struct scsi_driver sd_template = { }; /* - * Dummy kobj_map->probe function. - * The default ->probe function will call modprobe, which is - * pointless as this module is already loaded. + * Don't request a new module, as that could deadlock in multipath + * environment. */ -static struct kobject *sd_default_probe(dev_t devt, int *partno, void *data) +static void sd_default_probe(dev_t devt) { - return NULL; } /* @@ -3479,9 +3477,6 @@ static int sd_remove(struct device *dev) free_opal_dev(sdkp->opal_dev); - blk_register_region(devt, SD_MINORS, NULL, - sd_default_probe, NULL, NULL); - mutex_lock(&sd_ref_mutex); dev_set_drvdata(dev, NULL); put_device(&sdkp->dev); @@ -3671,11 +3666,9 @@ static int __init init_sd(void) SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n")); for (i = 0; i < SD_MAJORS; i++) { - if (register_blkdev(sd_major(i), "sd") != 0) + if (__register_blkdev(sd_major(i), "sd", sd_default_probe)) continue; majors++; - blk_register_region(sd_major(i), SD_MINORS, NULL, - sd_default_probe, NULL, NULL); } if (!majors) @@ -3748,10 +3741,8 @@ static void __exit exit_sd(void) class_unregister(&sd_disk_class); - for (i = 0; i < SD_MAJORS; i++) { - blk_unregister_region(sd_major(i), SD_MINORS); + for (i = 0; i < SD_MAJORS; i++) unregister_blkdev(sd_major(i), "sd"); - } } module_init(init_sd);