From patchwork Sun Aug 30 06:24:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 257824 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=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 6F7D9C433E7 for ; Sun, 30 Aug 2020 06:26:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D60B20693 for ; Sun, 30 Aug 2020 06:26:36 +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="SCkSbq7W" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728775AbgH3G0e (ORCPT ); Sun, 30 Aug 2020 02:26:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58510 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726506AbgH3GZD (ORCPT ); Sun, 30 Aug 2020 02:25:03 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7138C061575; Sat, 29 Aug 2020 23:25:01 -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=+cMW5JtsVeNS2FjWWdcDP87J0ElpYqiX0+V9AmGsl5g=; b=SCkSbq7Wecx0IWQUpw/Q2zwHXv 6EP1GaIRNZAQGBOe4aBGZvp/tqSOwTy4gbS1Mqj5sOCjAHOdouUNUZgKIrkFWf9Ajhps1DOqWoNOH z3SHjwsWxYDPX9R885hsF2Tc/D5K6Q1ZbEqAdYGqqg2+OiQ4loGElLVt9n1pNLF1ynJTmuolPzdWi jwA6CdFw3Ip1iJLXPS1fWnaBaj7KBwySYFpaeZc9igdhH3Hk8cFNlLcjTZPRs6d490ffuZJA3sWM8 sd9UAFkNnLtKANuiMP/uCcuouXpPqG6EW7XS0F6b7ZILgRZ/xpLUjzdRJyYYAxTYYDOXGjfzJqPNd ZDulh73g==; 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 1kCGlm-0002MV-6W; Sun, 30 Aug 2020 06:24:50 +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 04/19] block: split block_class_lock Date: Sun, 30 Aug 2020 08:24:30 +0200 Message-Id: <20200830062445.1199128-5-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 Split the block_class_lock mutex into one each to protect bdev_map and major_names. Signed-off-by: Christoph Hellwig --- block/genhd.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index df6485223a2c3d..0ae6210e141ee5 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -25,7 +25,6 @@ #include "blk.h" -static DEFINE_MUTEX(block_class_lock); static struct kobject *block_depr; struct bdev_map { @@ -37,6 +36,7 @@ struct bdev_map { int (*lock)(dev_t, void *); void *data; } *bdev_map[255]; +static DEFINE_MUTEX(bdev_map_lock); /* for extended dynamic devt allocation, currently only one major is used */ #define NR_EXT_DEVT (1 << MINORBITS) @@ -403,6 +403,7 @@ static struct blk_major_name { int major; char name[16]; } *major_names[BLKDEV_MAJOR_HASH_SIZE]; +static DEFINE_MUTEX(major_names_lock); /* index in the above - for now: assume no multimajor ranges */ static inline int major_to_index(unsigned major) @@ -415,11 +416,11 @@ void blkdev_show(struct seq_file *seqf, off_t offset) { struct blk_major_name *dp; - mutex_lock(&block_class_lock); + mutex_lock(&major_names_lock); for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next) if (dp->major == offset) seq_printf(seqf, "%3d %s\n", dp->major, dp->name); - mutex_unlock(&block_class_lock); + mutex_unlock(&major_names_lock); } #endif /* CONFIG_PROC_FS */ @@ -448,7 +449,7 @@ int register_blkdev(unsigned int major, const char *name) struct blk_major_name **n, *p; int index, ret = 0; - mutex_lock(&block_class_lock); + mutex_lock(&major_names_lock); /* temporary */ if (major == 0) { @@ -501,7 +502,7 @@ int register_blkdev(unsigned int major, const char *name) kfree(p); } out: - mutex_unlock(&block_class_lock); + mutex_unlock(&major_names_lock); return ret; } @@ -513,7 +514,7 @@ void unregister_blkdev(unsigned int major, const char *name) struct blk_major_name *p = NULL; int index = major_to_index(major); - mutex_lock(&block_class_lock); + mutex_lock(&major_names_lock); for (n = &major_names[index]; *n; n = &(*n)->next) if ((*n)->major == major) break; @@ -523,7 +524,7 @@ void unregister_blkdev(unsigned int major, const char *name) p = *n; *n = p->next; } - mutex_unlock(&block_class_lock); + mutex_unlock(&major_names_lock); kfree(p); } @@ -674,7 +675,7 @@ void blk_register_region(dev_t devt, unsigned long range, struct module *module, p->data = data; } - mutex_lock(&block_class_lock); + mutex_lock(&bdev_map_lock); for (i = 0, p -= n; i < n; i++, p++, index++) { struct bdev_map **s = &bdev_map[index % 255]; while (*s && (*s)->range < range) @@ -682,7 +683,7 @@ void blk_register_region(dev_t devt, unsigned long range, struct module *module, p->next = *s; *s = p; } - mutex_unlock(&block_class_lock); + mutex_unlock(&bdev_map_lock); } EXPORT_SYMBOL(blk_register_region); @@ -693,7 +694,7 @@ void blk_unregister_region(dev_t devt, unsigned long range) unsigned i; struct bdev_map *found = NULL; - mutex_lock(&block_class_lock); + mutex_lock(&bdev_map_lock); for (i = 0; i < min(n, 255u); i++, index++) { struct bdev_map **s; for (s = &bdev_map[index % 255]; *s; s = &(*s)->next) { @@ -706,7 +707,7 @@ void blk_unregister_region(dev_t devt, unsigned long range) } } } - mutex_unlock(&block_class_lock); + mutex_unlock(&bdev_map_lock); kfree(found); } EXPORT_SYMBOL(blk_unregister_region); @@ -1041,7 +1042,7 @@ static struct gendisk *lookup_gendisk(dev_t dev, int *partno) unsigned long best = ~0UL; retry: - mutex_lock(&block_class_lock); + mutex_lock(&bdev_map_lock); for (p = bdev_map[MAJOR(dev) % 255]; p; p = p->next) { struct kobject *(*probe)(dev_t, int *, void *); struct module *owner; @@ -1062,7 +1063,7 @@ static struct gendisk *lookup_gendisk(dev_t dev, int *partno) module_put(owner); continue; } - mutex_unlock(&block_class_lock); + mutex_unlock(&bdev_map_lock); kobj = probe(dev, partno, data); /* Currently ->owner protects _only_ ->probe() itself. */ module_put(owner); @@ -1070,7 +1071,7 @@ static struct gendisk *lookup_gendisk(dev_t dev, int *partno) return dev_to_disk(kobj_to_dev(kobj)); goto retry; } - mutex_unlock(&block_class_lock); + mutex_unlock(&bdev_map_lock); return NULL; }