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 us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 04525C83F11 for ; Mon, 28 Aug 2023 14:04:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1693231439; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references:list-id:list-help:list-unsubscribe: list-subscribe:list-post; bh=EoGjlAqIr84+dzTRIVSh6MnXuXBwrPpcJyhAY3N5ock=; b=R5GtVEApcHOr86u//v35TlqoIe2ZbzWETM67OIxjXVAQ6dMgU/pwvaUDXiITberSToYYuW Huq3sNKTS5QPeKeNuvpY6PnV/TXMXMK42gClRirkbRwyuQCpvjR2J/+HzuFSOCKzwt9b2u rSd4ZIEmPlG1ifbcQnfHCVp4Q8H3DS4= Received: from mimecast-mx02.redhat.com (66.187.233.73 [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-177-wla5U5OUPyW-EYCjd7rBNw-1; Mon, 28 Aug 2023 10:03:27 -0400 X-MC-Unique: wla5U5OUPyW-EYCjd7rBNw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 84BFE29DD992; Mon, 28 Aug 2023 14:02:54 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4BB2240C2063; Mon, 28 Aug 2023 14:02:54 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id 1473B1946588; Mon, 28 Aug 2023 14:02:54 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id C42121946587 for ; Mon, 28 Aug 2023 14:02:33 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id AEA602026D76; Mon, 28 Aug 2023 14:02:33 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast06.extmail.prod.ext.rdu2.redhat.com [10.11.55.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A5D712026D4B for ; Mon, 28 Aug 2023 14:02:33 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-inbound-delivery-1.mimecast.com [207.211.31.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 62EE018E52A3 for ; Mon, 28 Aug 2023 14:02:33 +0000 (UTC) Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-371-ku_VA72INjuLFc30iNKSww-1; Mon, 28 Aug 2023 10:02:23 -0400 X-MC-Unique: ku_VA72INjuLFc30iNKSww-1 Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux)) id 1qacoc-001ZYo-2Z; Mon, 28 Aug 2023 14:02:03 +0000 Date: Mon, 28 Aug 2023 15:02:02 +0100 From: Al Viro To: Christoph Hellwig Message-ID: <20230828140202.GX3390869@ZenIV> References: <20230601145904.1385409-1-hch@lst.de> <20230601145904.1385409-4-hch@lst.de> <20230827194122.GA325446@ZenIV> <20230828123023.GA11084@lst.de> MIME-Version: 1.0 In-Reply-To: <20230828123023.GA11084@lst.de> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Subject: Re: [Cluster-devel] [PATCH 03/12] filemap: update ki_pos in generic_perform_write X-BeenThere: cluster-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: "\[Cluster devel\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Darrick J. Wong" , linux-mm@kvack.org, Miklos Szeredi , Matthew Wilcox , cluster-devel@redhat.com, Ilya Dryomov , linux-ext4@vger.kernel.org, Chao Yu , linux-nfs@vger.kernel.org, linux-block@vger.kernel.org, Damien Le Moal , Hannes Reinecke , Jaegeuk Kim , ceph-devel@vger.kernel.org, Xiubo Li , Trond Myklebust , Jens Axboe , Christian Brauner , Theodore Ts'o , linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, Anna Schumaker , linux-fsdevel@vger.kernel.org, Andrew Morton Errors-To: cluster-devel-bounces@redhat.com Sender: "Cluster-devel" X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: zeniv.linux.org.uk Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Aug 28, 2023 at 02:30:23PM +0200, Christoph Hellwig wrote: > On Sun, Aug 27, 2023 at 08:41:22PM +0100, Al Viro wrote: > > That part is somewhat fishy - there's a case where you return a positive value > > and advance ->ki_pos by more than that amount. I really wonder if all callers > > of ->write_iter() are OK with that. Consider e.g. this: > > This should not exist in the latest version merged by Jens. Can you > check if you still see issues in the version in the block tree or > linux-next. Still does - the problem has migrated into direct_write_fallback(), but that hadn't changed the situation. We are still left with ->ki_pos bumped by generic_perform_write() (evaluated as an argument of direct_write_fallback() now) and *not* retraced in case when direct_write_fallback() decides to discard the buffered write result. Both in -next and in mainline (since 6.5-rc1).