From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=no 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 E4ED4C2D0A5 for ; Thu, 3 Sep 2020 08:15:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C01662145D for ; Thu, 3 Sep 2020 08:15:42 +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="wWWW6aYY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728027AbgICIBh (ORCPT ); Thu, 3 Sep 2020 04:01:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60916 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727065AbgICIBc (ORCPT ); Thu, 3 Sep 2020 04:01:32 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE2A3C061244; Thu, 3 Sep 2020 01:01:31 -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: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:In-Reply-To:References; bh=cU305cxFBo6tm5/dcumAYM77XH5iQN9l01UIc+MQ8ms=; b=wWWW6aYY0aagDmpZ1bPiSvTpQw hJm4tzGwj6/QUrIm6ZDBPRuSbs+oSQf3GZeEe/T3oMzvl2i2cvcS8HU0gIeJExqwloJMuvqD+tyUm /5CWj/mQRXnLWL5bbRHRR7Gi9/gFtwkcOHZ3GHFxXuEpkeqayyIaBuePt7xW9LIgNzgw5Nins47i/ BsLowowCTOTKIIDe5AHHnQPXyuGTLG+TkeO/7krX6/GSvGxLHKw2GijdhXLkTHKMxfpZWQrLqDvzM osFtIVQYGnxEdZK6JbWvEPOOyuMeoSfkEwcWm+DIPXHs7xcLJi5qnAJIEjerenE5BSTQzTmGTqMiy bNvKvSow==; Received: from [2001:4bb8:184:af1:c70:4a89:bc61:2] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDkBL-0006Zq-V2; Thu, 03 Sep 2020 08:01:20 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Denis Efremov , "David S. Miller" , Song Liu , Al Viro , Finn Thain , Michael Schmitz , 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: simplify gendisk lookup and remove struct block_device aliases v3 Date: Thu, 3 Sep 2020 10:01:00 +0200 Message-Id: <20200903080119.441674-1-hch@lst.de> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-raid-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org Hi all, this series removes the annoying struct block_device aliases, which can happen for a bunch of old floppy drivers (and z2ram). In that case multiple struct block device instances for different dev_t's can point to the same gendisk, without being partitions. The cause for that is the probe/get callback registered through blk_register_regions. This series removes blk_register_region entirely, splitting it it into a simple xarray lookup of registered gendisks, and a probe callback stored in the major_names array that can be used for modprobe overrides or creating devices on demands when no gendisk is found. The old remapping is gone entirely, and instead the 4 remaining drivers just register a gendisk for each operating mode. In case of the two drivers that have lots of aliases that is done on-demand using the new probe callback, while for the other two I simply register all at probe time to keep things simple. Note that the m68k drivers are compile tested only. Changes since v2: - fix a wrong variable passed to ERR_PTR in the floppy driver - slightly adjust the del_gendisk cleanups to prepare for the next series touching this area Changes since v1: - add back a missing kobject_put in the cdev code - improve the xarray delete loops Diffstat: b/block/genhd.c | 183 +++++++-------- b/drivers/base/Makefile | 2 b/drivers/block/amiflop.c | 98 ++++---- b/drivers/block/ataflop.c | 135 +++++++---- b/drivers/block/brd.c | 39 --- b/drivers/block/floppy.c | 154 ++++++++---- b/drivers/block/loop.c | 30 -- b/drivers/block/swim.c | 17 - b/drivers/block/z2ram.c | 547 ++++++++++++++++++++++------------------------ b/drivers/ide/ide-probe.c | 66 ----- b/drivers/ide/ide-tape.c | 2 b/drivers/md/md.c | 21 - b/drivers/scsi/sd.c | 19 - b/fs/char_dev.c | 94 +++---- b/fs/dcache.c | 1 b/fs/internal.h | 5 b/include/linux/genhd.h | 12 - b/include/linux/ide.h | 3 drivers/base/map.c | 154 ------------ include/linux/kobj_map.h | 20 - 20 files changed, 686 insertions(+), 916 deletions(-)