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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 4A944C5519F for ; Mon, 30 Nov 2020 07:15:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 033F2206CA for ; Mon, 30 Nov 2020 07:15:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726024AbgK3HPE (ORCPT ); Mon, 30 Nov 2020 02:15:04 -0500 Received: from mx2.suse.de ([195.135.220.15]:40204 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725902AbgK3HPE (ORCPT ); Mon, 30 Nov 2020 02:15:04 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 82ED1AC55; Mon, 30 Nov 2020 07:14:22 +0000 (UTC) Subject: Re: [PATCH 16/45] block: switch bdgrab to use igrab To: Christoph Hellwig , Jens Axboe Cc: Tejun Heo , Josef Bacik , Coly Li , Mike Snitzer , Greg Kroah-Hartman , Jan Kara , Johannes Thumshirn , dm-devel@redhat.com, Jan Kara , linux-block@vger.kernel.org, linux-bcache@vger.kernel.org, linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org References: <20201128161510.347752-1-hch@lst.de> <20201128161510.347752-17-hch@lst.de> From: Hannes Reinecke Message-ID: <595de89b-944c-a694-c63e-7600370d28fc@suse.de> Date: Mon, 30 Nov 2020 08:14:22 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20201128161510.347752-17-hch@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 11/28/20 5:14 PM, Christoph Hellwig wrote: > All of the current callers already have a reference, but to prepare for > additional users ensure bdgrab returns NULL if the block device is beeing > freed. > > Signed-off-by: Christoph Hellwig > --- > fs/block_dev.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/block_dev.c b/fs/block_dev.c > index d707ab376da86e..962fabe8a67b83 100644 > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -894,10 +894,14 @@ static struct block_device *bdget(dev_t dev) > /** > * bdgrab -- Grab a reference to an already referenced block device > * @bdev: Block device to grab a reference to. > + * > + * Returns the block_device with an additional reference when successful, > + * or NULL if the inode is already beeing freed. > */ > struct block_device *bdgrab(struct block_device *bdev) > { > - ihold(bdev->bd_inode); > + if (!igrab(bdev->bd_inode)) > + return NULL; > return bdev; > } > EXPORT_SYMBOL(bdgrab); > Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer