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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 6B2A9C2F3BE for ; Mon, 21 Jan 2019 13:58:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 347952084C for ; Mon, 21 Jan 2019 13:58:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548079080; bh=GSCxyao6A1PkZadgSNRq83ybpgG4yrWWQD99x9b2mKs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tl6ZsCc1vdOyajFoaFn7jygcyo6FkmXX5MPz2MiP+4yGbR4fHjcTox3aIimQ0Y92x sQwMCrjoh1w1qQg8Q0Q4R6ZBQH0WcW+16ZlerLzlr810oHPh8k64Rj/1DJVYnrTR0H FF1qKaau2s0bVrEPHxHbOrgGcEgSkAVL7Q2/YKyU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731879AbfAUN4O (ORCPT ); Mon, 21 Jan 2019 08:56:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:41240 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731874AbfAUN4M (ORCPT ); Mon, 21 Jan 2019 08:56:12 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C4AB420861; Mon, 21 Jan 2019 13:56:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548078971; bh=GSCxyao6A1PkZadgSNRq83ybpgG4yrWWQD99x9b2mKs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lOvvjy/vLkgAKZiuIuhw56iuP6EiL3StrgOwHGiVjyx0Jr+JxPEtP5ScIUCqGsEaR xf+e+MIQKykb+g2eV1QVBpSTS9tVXGJIIMwpOZH8YXLSvkJV8PrDjppt+s4uK3MK1B Ct8FcpnNv5dIrZrqw9MZ4CjpZCtVqzEZxgVlS+KU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , Jens Axboe Subject: [PATCH 4.9 48/51] loop: Get rid of loop_index_mutex Date: Mon, 21 Jan 2019 14:44:44 +0100 Message-Id: <20190121122458.478713698@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190121122453.700446926@linuxfoundation.org> References: <20190121122453.700446926@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit 0a42e99b58a208839626465af194cfe640ef9493 upstream. Now that loop_ctl_mutex is global, just get rid of loop_index_mutex as there is no good reason to keep these two separate and it just complicates the locking. Signed-off-by: Jan Kara Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/loop.c | 39 ++++++++++++++++++++------------------- 1 file changed, 20 insertions(+), 19 deletions(-) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -81,7 +81,6 @@ #include static DEFINE_IDR(loop_index_idr); -static DEFINE_MUTEX(loop_index_mutex); static DEFINE_MUTEX(loop_ctl_mutex); static int max_part; @@ -1560,9 +1559,11 @@ static int lo_compat_ioctl(struct block_ static int lo_open(struct block_device *bdev, fmode_t mode) { struct loop_device *lo; - int err = 0; + int err; - mutex_lock(&loop_index_mutex); + err = mutex_lock_killable(&loop_ctl_mutex); + if (err) + return err; lo = bdev->bd_disk->private_data; if (!lo) { err = -ENXIO; @@ -1571,7 +1572,7 @@ static int lo_open(struct block_device * atomic_inc(&lo->lo_refcnt); out: - mutex_unlock(&loop_index_mutex); + mutex_unlock(&loop_ctl_mutex); return err; } @@ -1580,12 +1581,11 @@ static void lo_release(struct gendisk *d struct loop_device *lo; int err; - mutex_lock(&loop_index_mutex); + mutex_lock(&loop_ctl_mutex); lo = disk->private_data; if (atomic_dec_return(&lo->lo_refcnt)) - goto unlock_index; + goto out_unlock; - mutex_lock(&loop_ctl_mutex); if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { /* * In autoclear mode, stop the loop thread @@ -1593,7 +1593,7 @@ static void lo_release(struct gendisk *d */ err = loop_clr_fd(lo); if (!err) - goto unlock_index; + return; } else { /* * Otherwise keep thread (if running) and config, @@ -1602,9 +1602,8 @@ static void lo_release(struct gendisk *d loop_flush(lo); } +out_unlock: mutex_unlock(&loop_ctl_mutex); -unlock_index: - mutex_unlock(&loop_index_mutex); } static const struct block_device_operations lo_fops = { @@ -1890,7 +1889,7 @@ static struct kobject *loop_probe(dev_t struct kobject *kobj; int err; - mutex_lock(&loop_index_mutex); + mutex_lock(&loop_ctl_mutex); err = loop_lookup(&lo, MINOR(dev) >> part_shift); if (err < 0) err = loop_add(&lo, MINOR(dev) >> part_shift); @@ -1898,7 +1897,7 @@ static struct kobject *loop_probe(dev_t kobj = NULL; else kobj = get_disk(lo->lo_disk); - mutex_unlock(&loop_index_mutex); + mutex_unlock(&loop_ctl_mutex); *part = 0; return kobj; @@ -1908,9 +1907,13 @@ static long loop_control_ioctl(struct fi unsigned long parm) { struct loop_device *lo; - int ret = -ENOSYS; + int ret; + + ret = mutex_lock_killable(&loop_ctl_mutex); + if (ret) + return ret; - mutex_lock(&loop_index_mutex); + ret = -ENOSYS; switch (cmd) { case LOOP_CTL_ADD: ret = loop_lookup(&lo, parm); @@ -1924,7 +1927,6 @@ static long loop_control_ioctl(struct fi ret = loop_lookup(&lo, parm); if (ret < 0) break; - mutex_lock(&loop_ctl_mutex); if (lo->lo_state != Lo_unbound) { ret = -EBUSY; mutex_unlock(&loop_ctl_mutex); @@ -1936,7 +1938,6 @@ static long loop_control_ioctl(struct fi break; } lo->lo_disk->private_data = NULL; - mutex_unlock(&loop_ctl_mutex); idr_remove(&loop_index_idr, lo->lo_number); loop_remove(lo); break; @@ -1946,7 +1947,7 @@ static long loop_control_ioctl(struct fi break; ret = loop_add(&lo, -1); } - mutex_unlock(&loop_index_mutex); + mutex_unlock(&loop_ctl_mutex); return ret; } @@ -2029,10 +2030,10 @@ static int __init loop_init(void) THIS_MODULE, loop_probe, NULL, NULL); /* pre-create number of devices given by config or max_loop */ - mutex_lock(&loop_index_mutex); + mutex_lock(&loop_ctl_mutex); for (i = 0; i < nr; i++) loop_add(&lo, i); - mutex_unlock(&loop_index_mutex); + mutex_unlock(&loop_ctl_mutex); printk(KERN_INFO "loop: module loaded\n"); return 0;