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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7896C7618E for ; Mon, 24 Apr 2023 06:22:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 268616B0071; Mon, 24 Apr 2023 02:22:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2189A6B0074; Mon, 24 Apr 2023 02:22:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 107A66B0075; Mon, 24 Apr 2023 02:22:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 045D76B0071 for ; Mon, 24 Apr 2023 02:22:26 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id C521AA016B for ; Mon, 24 Apr 2023 06:22:25 +0000 (UTC) X-FDA: 80715290250.21.B024FDC Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf27.hostedemail.com (Postfix) with ESMTP id F3B264001F for ; Mon, 24 Apr 2023 06:22:23 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=none; spf=none (imf27.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1682317344; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=m2RVkRM/RRfziaaa7EwKPpi+1lzJHXGOtI0HTD/B43k=; b=BXwaNlhDOxnTEeEj0Bse3YO7ktYItRGqtZJhzMFOrHUNrQ/6tX2XnRPRVd7Jj0XXm3Qd2R TZT1Y50w06pJw5/xWeyOehDCJQWea3u2vrylGICtjsNZLDpWqojLqzECE8E5FIRf0N/ARc Iv7ELQbT9JAyhcaIZHlKESN9YuvuKi4= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=none; spf=none (imf27.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1682317344; a=rsa-sha256; cv=none; b=j9rPpAfDglBpdvefAnnSLHJV1bgEk8m912eGecMltPoKpgb/FECRgbAKcHWATwzaW/m9b/ qx4jjgq72DjZ0KVjrzBCr369iBXyD6JxrihQ3+SSbWVIzHm5Us3Q7pwgNFivxNR9l/goRp iTTgtSTfixg2V1dql8jLJyIRO8GHqm4= Received: by verein.lst.de (Postfix, from userid 2407) id 50A3B68B05; Mon, 24 Apr 2023 08:22:20 +0200 (CEST) Date: Mon, 24 Apr 2023 08:22:20 +0200 From: Christoph Hellwig To: "Darrick J. Wong" Cc: Christoph Hellwig , Jens Axboe , Miklos Szeredi , Andrew Morton , David Howells , Matthew Wilcox , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 11/17] iomap: assign current->backing_dev_info in iomap_file_buffered_write Message-ID: <20230424062220.GA10368@lst.de> References: <20230424054926.26927-1-hch@lst.de> <20230424054926.26927-12-hch@lst.de> <20230424061825.GO360889@frogsfrogsfrogs> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230424061825.GO360889@frogsfrogsfrogs> User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: ia1jccy6dctgssdfhngsuua6if9npjfs X-Rspamd-Queue-Id: F3B264001F X-HE-Tag: 1682317343-564155 X-HE-Meta: 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 hapYnXhT WeJ2XPk8CQ1+13u/Y00U00uxDwDcx100pt/hPIXBc1C8JvH6w960O3EuxNMK7c9D1HZ4RLoERTB64Wk/fjt4HUovJSRzSOPzrfSm6PVS+2lwLG1E= 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: On Sun, Apr 23, 2023 at 11:18:25PM -0700, Darrick J. Wong wrote: > > @@ -876,8 +877,11 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *i, > > if (iocb->ki_flags & IOCB_NOWAIT) > > iter.flags |= IOMAP_NOWAIT; > > > > + current->backing_dev_info = inode_to_bdi(iter.inode); > > Dumb question from me late on a Sunday night, but does the iomap_unshare > code need to set this too? Since it works by dirtying pagecache folios > without actually changing the contents? A very good question that I have no answer for. The current->backing_dev_info mechanism confuses the heck out of me and appears basically undocumented.