From patchwork Thu Jul 16 14:33:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11667723 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 07B2560D for ; Thu, 16 Jul 2020 14:33:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1E7420825 for ; Thu, 16 Jul 2020 14:33:16 +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="rLYHFdOd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728345AbgGPOdQ (ORCPT ); Thu, 16 Jul 2020 10:33:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727844AbgGPOdP (ORCPT ); Thu, 16 Jul 2020 10:33:15 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA8A1C061755 for ; Thu, 16 Jul 2020 07:33:15 -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=WbJncdurVVf0z70ZOfQahFzc+lpUBewmye/8KNALHHU=; b=rLYHFdOdN5xvl9Mlpxi6FkrgZV wCO974N+vj68r5FC8NNYVmHP/HVEAYggffgz5TvYGMt6RmBKdHb//n0QNTRLqPT8gOLbkuq3/4qqu pvorkBf47LXUYUARQ826fDk0cUFKZS7GHnK5NgGXPnCXnlPCMO2uYxcc2iHe5wVSoJUY49tl+IWpQ O8RCQ2LvunNntCt4LziqdMwOCGm/bis5sp9yMl7H2CzbmHrmHxyr0BljN1x3Bb96Gu4+6d4Z5xhFy XXT6meMFIhuoipN4RIIGtgLchYggZgUMGpuhup9vPj2dvJi6hWzdBmgMtHBqptGUfao3a1PcRfs6s t0NU3dVw==; Received: from [2001:4bb8:105:4a81:1bd9:4dba:216e:37b8] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jw4wj-0000C1-9j; Thu, 16 Jul 2020 14:33:13 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Tejun Heo , linux-block@vger.kernel.org Subject: [PATCH 1/4] block: simplify the restart case in __blkdev_get Date: Thu, 16 Jul 2020 16:33:07 +0200 Message-Id: <20200716143310.473136-2-hch@lst.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200716143310.473136-1-hch@lst.de> References: <20200716143310.473136-1-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-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Insted of duplicating all the cleanup logic jump to the code that cleans up anyway, and restart after that. Signed-off-by: Christoph Hellwig Acked-by: Tejun Heo Reviewed-by: Hannes Reinecke --- fs/block_dev.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index a36d5b6907ea4e..376832250c8e91 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1517,7 +1517,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) int ret; int partno; int perm = 0; - bool first_open = false; + bool first_open = false, need_restart; if (mode & FMODE_READ) perm |= MAY_READ; @@ -1533,7 +1533,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) } restart: - + need_restart = false; ret = -ENXIO; disk = bdev_get_gendisk(bdev, &partno); if (!disk) @@ -1556,19 +1556,12 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) ret = 0; if (disk->fops->open) { ret = disk->fops->open(bdev, mode); - if (ret == -ERESTARTSYS) { - /* Lost a race with 'disk' being - * deleted, try again. - * See md.c - */ - disk_put_part(bdev->bd_part); - bdev->bd_part = NULL; - bdev->bd_disk = NULL; - mutex_unlock(&bdev->bd_mutex); - disk_unblock_events(disk); - put_disk_and_module(disk); - goto restart; - } + /* + * If we lost a race with 'disk' being deleted, + * try again. See md.c + */ + if (ret == -ERESTARTSYS) + need_restart = true; } if (!ret) { @@ -1647,6 +1640,8 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) mutex_unlock(&bdev->bd_mutex); disk_unblock_events(disk); put_disk_and_module(disk); + if (need_restart) + goto restart; out: return ret;