From patchwork Sat Nov 28 16:14:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11937631 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=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 60116C63697 for ; Sat, 28 Nov 2020 16:16:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0ED78246C0 for ; Sat, 28 Nov 2020 16:16:07 +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="Sh9Kvg4m" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0ED78246C0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CDB178D0010; Sat, 28 Nov 2020 11:15:49 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C6AA28D0017; Sat, 28 Nov 2020 11:15:49 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 81EA38D0010; Sat, 28 Nov 2020 11:15:49 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0198.hostedemail.com [216.40.44.198]) by kanga.kvack.org (Postfix) with ESMTP id 5CF488D0010 for ; Sat, 28 Nov 2020 11:15:49 -0500 (EST) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 0FC85181AEF21 for ; Sat, 28 Nov 2020 16:15:49 +0000 (UTC) X-FDA: 77534328018.18.toe01_0015c7627392 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin18.hostedemail.com (Postfix) with ESMTP id E6165100EDBE8 for ; Sat, 28 Nov 2020 16:15:48 +0000 (UTC) X-HE-Tag: toe01_0015c7627392 X-Filterd-Recvd-Size: 3029 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf43.hostedemail.com (Postfix) with ESMTP for ; Sat, 28 Nov 2020 16:15:48 +0000 (UTC) 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=+N9nj4aeGcaY7E1cQ0C8G5//2Sxe7PPFKlTYCp379Nc=; b=Sh9Kvg4mkZ4XkPadEWLnVIdZ3T saZLEqTiDzaNBysUYvfcJruhwPbuksCUFc+ke5gwjhVFkndBZ57UQ7fn4y7YpckR8b4ZDwiQukngD 3h/QoUNnAjcd3Kh+WVbHZCWu4czXKsHXG2oNQ/C57Y7zLCfqJvaPsuSEwog3vAo4qKbHYDBeHNS05 j0CdaOXRTKvrHx3+Vjw2wphhy2k7x7Rqdy6fTts7RjMxuXtZEmSClWEQYqBDZpRO+fKBAa4QqDo4M WYpyRFXXAZlz172qFqypLsbK3XlhKzPxNn+C11J542iRyoxaNNArlsXG8/JrIEaIBLhF136iBBo3g l+1fCoyg==; Received: from [2001:4bb8:18c:1dd6:48f3:741a:602e:7fdd] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kj2sr-0000G4-Tr; Sat, 28 Nov 2020 16:15:38 +0000 From: Christoph Hellwig To: 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 Subject: [PATCH 16/45] block: switch bdgrab to use igrab Date: Sat, 28 Nov 2020 17:14:41 +0100 Message-Id: <20201128161510.347752-17-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201128161510.347752-1-hch@lst.de> References: <20201128161510.347752-1-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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 Reviewed-by: Hannes Reinecke Reviewed-by: Jan Kara Reviewed-by: Johannes Thumshirn --- 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);