From patchwork Thu Sep 27 11:36:42 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 10617841 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AEDE71759 for ; Thu, 27 Sep 2018 11:37:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A10862B1D7 for ; Thu, 27 Sep 2018 11:37:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 95F3E2B200; Thu, 27 Sep 2018 11:37:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2D33A2B1D7 for ; Thu, 27 Sep 2018 11:37:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727112AbeI0RzG (ORCPT ); Thu, 27 Sep 2018 13:55:06 -0400 Received: from mx2.suse.de ([195.135.220.15]:37120 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727200AbeI0RzF (ORCPT ); Thu, 27 Sep 2018 13:55:05 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D431FB12D; Thu, 27 Sep 2018 11:37:10 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 91BA61E3617; Thu, 27 Sep 2018 13:37:09 +0200 (CEST) From: Jan Kara To: Jens Axboe Cc: , Tetsuo Handa , Jan Kara Subject: [PATCH 04/14] loop: Get rid of loop_index_mutex Date: Thu, 27 Sep 2018 13:36:42 +0200 Message-Id: <20180927113652.5422-5-jack@suse.cz> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20180927113652.5422-1-jack@suse.cz> References: <20180927113652.5422-1-jack@suse.cz> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- drivers/block/loop.c | 38 ++++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 20 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index cc43d835fe6f..e35707fb8318 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -83,7 +83,6 @@ #include static DEFINE_IDR(loop_index_idr); -static DEFINE_MUTEX(loop_index_mutex); static DEFINE_MUTEX(loop_ctl_mutex); static int max_part; @@ -1627,9 +1626,11 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, 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; @@ -1638,7 +1639,7 @@ static int lo_open(struct block_device *bdev, fmode_t mode) atomic_inc(&lo->lo_refcnt); out: - mutex_unlock(&loop_index_mutex); + mutex_unlock(&loop_ctl_mutex); return err; } @@ -1647,12 +1648,11 @@ static void lo_release(struct gendisk *disk, fmode_t mode) 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 @@ -1660,7 +1660,7 @@ static void lo_release(struct gendisk *disk, fmode_t mode) */ err = loop_clr_fd(lo); if (!err) - goto unlock_index; + return; } else if (lo->lo_state == Lo_bound) { /* * Otherwise keep thread (if running) and config, @@ -1670,9 +1670,8 @@ static void lo_release(struct gendisk *disk, fmode_t mode) blk_mq_unfreeze_queue(lo->lo_queue); } +out_unlock: mutex_unlock(&loop_ctl_mutex); -unlock_index: - mutex_unlock(&loop_index_mutex); } static const struct block_device_operations lo_fops = { @@ -1973,7 +1972,7 @@ static struct kobject *loop_probe(dev_t dev, int *part, void *data) 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); @@ -1981,7 +1980,7 @@ static struct kobject *loop_probe(dev_t dev, int *part, void *data) kobj = NULL; else kobj = get_disk_and_module(lo->lo_disk); - mutex_unlock(&loop_index_mutex); + mutex_unlock(&loop_ctl_mutex); *part = 0; return kobj; @@ -1993,7 +1992,10 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, struct loop_device *lo; int ret = -ENOSYS; - mutex_lock(&loop_index_mutex); + ret = mutex_lock_killable(&loop_ctl_mutex); + if (ret) + return ret; + switch (cmd) { case LOOP_CTL_ADD: ret = loop_lookup(&lo, parm); @@ -2007,9 +2009,6 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, ret = loop_lookup(&lo, parm); if (ret < 0) break; - ret = mutex_lock_killable(&loop_ctl_mutex); - if (ret) - break; if (lo->lo_state != Lo_unbound) { ret = -EBUSY; mutex_unlock(&loop_ctl_mutex); @@ -2021,7 +2020,6 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, break; } lo->lo_disk->private_data = NULL; - mutex_unlock(&loop_ctl_mutex); idr_remove(&loop_index_idr, lo->lo_number); loop_remove(lo); break; @@ -2031,7 +2029,7 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd, break; ret = loop_add(&lo, -1); } - mutex_unlock(&loop_index_mutex); + mutex_unlock(&loop_ctl_mutex); return ret; } @@ -2115,10 +2113,10 @@ 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;