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 Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 641D3C88CB2 for ; Fri, 25 Aug 2023 01:59:42 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=linux.org.uk header.i=@linux.org.uk header.a=rsa-sha256 header.s=zeniv-20220401 header.b=bxxlNJ96; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4RX36h5sqMz3cCj for ; Fri, 25 Aug 2023 11:59:40 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=linux.org.uk header.i=@linux.org.uk header.a=rsa-sha256 header.s=zeniv-20220401 header.b=bxxlNJ96; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=ftp.linux.org.uk (client-ip=2a03:a000:7:0:5054:ff:fe1c:15ff; helo=zeniv.linux.org.uk; envelope-from=viro@ftp.linux.org.uk; receiver=lists.ozlabs.org) Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [IPv6:2a03:a000:7:0:5054:ff:fe1c:15ff]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4RX36V6h22z2yhL for ; Fri, 25 Aug 2023 11:59:28 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=GqmLor0hgV4H3x7IuvuyaB/m3hDiUm8Yzrd7b9keFg8=; b=bxxlNJ96rsx4L2kKszQ8LF6ai5 iNtBNOQ6lzvCMPjrA8d2B5SKpMA8ehWy3QlKX8FPouK+kPzVIEZKx+nUetaQRW5JSdDZgZ40B7sUp hz637OO4Su1eEUgn8Gl/dIA4NQM5w6cHamU5x0h4uc+j+8uZ5OMjiX5dOjWaEByfsbwcty7NjoKFy 3XYbSKjy+5wYC+oyCRnyAV7fQupk+8Mu6cgtvaubPBjXdneuinMhpNkKRGbKhUYZMh2pnc+qlSq3t /phSE0e2tky2IO5H3c5MgeU2/J9SsgCPwQOsXy7U4/wxiV2850iLaIsQdHEKmyDTGxCmoecJk/YQG iXEtALAQ==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1qZM5z-000dvR-0M; Fri, 25 Aug 2023 01:58:43 +0000 Date: Fri, 25 Aug 2023 02:58:43 +0100 From: Al Viro To: Jan Kara Subject: Re: [PATCH v2 0/29] block: Make blkdev_get_by_*() return handle Message-ID: <20230825015843.GB95084@ZenIV> References: <20230810171429.31759-1-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230810171429.31759-1-jack@suse.cz> X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dave Kleikamp , jfs-discussion@lists.sourceforge.net, "Darrick J. Wong" , linux-nvme@lists.infradead.org, Joseph Qi , dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, Jack Wang , Alasdair Kergon , drbd-dev@lists.linbit.com, linux-s390@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-scsi@vger.kernel.org, Sergey Senozhatsky , Christoph Hellwig , xen-devel@lists.xenproject.org, Christian Borntraeger , Kent Overstreet , Sven Schnelle , linux-pm@vger.kernel.org, Mike Snitzer , Joern Engel , reiserfs-devel@vger.kernel.org, linux-block@vger.kernel.org, linux-bcache@vger.kernel.org, David Sterba , Jaegeuk Kim , Trond Myklebust , linux-raid@vger.kernel.org, linux-nfs@vger.kernel.org, linux-ext4@vger.kernel.org, Ted Tso , linux-mm@kvack.org, Song Liu , linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, Minchan Kim , ocfs2-devel@oss.oracle.com, Anna Schumaker , linux-fsdevel@vger.kernel.org, "Md. Haris Iqbal" , Andrew Morton , linux-erofs@lists.ozlabs.org, linux-btrfs@vger.kernel.org Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" On Fri, Aug 11, 2023 at 01:04:31PM +0200, Jan Kara wrote: > Hello, > > this is a v2 of the patch series which implements the idea of blkdev_get_by_*() > calls returning bdev_handle which is then passed to blkdev_put() [1]. This > makes the get and put calls for bdevs more obviously matching and allows us to > propagate context from get to put without having to modify all the users > (again!). In particular I need to propagate used open flags to blkdev_put() to > be able count writeable opens and add support for blocking writes to mounted > block devices. I'll send that series separately. > > The series is based on Christian's vfs tree as of yesterday as there is quite > some overlap. Patches have passed some reasonable testing - I've tested block > changes, md, dm, bcache, xfs, btrfs, ext4, swap. This obviously doesn't cover > everything so I'd like to ask respective maintainers to review / test their > changes. Thanks! I've pushed out the full branch to: > > git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs.git bdev_handle > > to ease review / testing. Hmm... Completely Insane Idea(tm): how about turning that thing inside out and having your bdev_open_by... return an actual opened struct file? After all, we do that for sockets and pipes just fine and that's a whole lot hotter area. Suppose we leave blkdev_open()/blkdev_release() as-is. No need to mess with what we have for normal opened files for block devices. And have block_open_by_dev() that would find bdev, etc., same yours does and shove it into anon file. Paired with plain fput() - no need to bother with new primitives for closing. With a helper returning I_BDEV(bdev_file_inode(file)) to get from those to bdev. NOTE: I'm not suggesting replacing ->s_bdev with struct file * if we do that - we want that value cached, obviously. Just store both... Not saying it's a good idea, but... might be interesting to look into. Comments?