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 B4464C636D4 for ; Mon, 13 Feb 2023 22:43:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 22C246B0075; Mon, 13 Feb 2023 17:43:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1DD20280002; Mon, 13 Feb 2023 17:43:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0A514280001; Mon, 13 Feb 2023 17:43:23 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id EC3436B0075 for ; Mon, 13 Feb 2023 17:43:22 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id BF9F780CBE for ; Mon, 13 Feb 2023 22:43:22 +0000 (UTC) X-FDA: 80463746244.27.A7438A4 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf22.hostedemail.com (Postfix) with ESMTP id EA238C001E for ; Mon, 13 Feb 2023 22:43:20 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="Iv5/cDwo"; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf22.hostedemail.com: domain of dhowells@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=dhowells@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1676328201; 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:dkim-signature; bh=/MvJyZLq27FWxSw/lw8AFrwhZrqpXu3dfjNVlytfVw4=; b=7ioVCs51VIKpPBKPCCzqPxwKGWbKtqB6qXcFnYrovBlGVBrMbo2KFRzr66CBnSB38TCfV0 J+VIexKsCh6XuVsjwu3Jq915HXZ/WfBS/Bm5fdt/ksvCFmJgsxOipNZvFXlJJBc6R75nKV ngzmz1nMI00mdCdtBmZRek/ABHNIoHY= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="Iv5/cDwo"; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf22.hostedemail.com: domain of dhowells@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=dhowells@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1676328201; a=rsa-sha256; cv=none; b=IebQC+RUbtchs1YzUan283LK9u4tdKUFFQfdq+xF+OMWttl5dePmA3rPsw3+luQfSRCnl0 Vt2rW6fyvoivb7WY/8lKwYqyWEtPVk0e9vkj6O9VjXEZN0IMfm4/VoFCgPu9xv9lnY8CCX d2vmrFOLpnYDoPMjHQCjR0QHJKMsFAQ= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1676328200; h=from:from: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; bh=/MvJyZLq27FWxSw/lw8AFrwhZrqpXu3dfjNVlytfVw4=; b=Iv5/cDwokr8oP+tvloES/1iDpJfZp9tBBtDR4NdyjqWAdxFswusSOxFIicg87WKOPlcq3C DFAMf3SWSbwzqVbmKbBKcExOuNmYqqMVI/gHGvZdwE9b2v4H2aDisH78+1yFPXxhnUpRYG TDXqUhNXYi9Y7OK5GzUvwG5jj6uOj8w= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [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-77-NYCZe6bNMO-V6g3bY9PIng-1; Mon, 13 Feb 2023 17:43:16 -0500 X-MC-Unique: NYCZe6bNMO-V6g3bY9PIng-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 964B02932487; Mon, 13 Feb 2023 22:43:15 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7053B401014C; Mon, 13 Feb 2023 22:43:13 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20230213180632.GA368628@roeck-us.net> References: <20230213180632.GA368628@roeck-us.net> <20230209102954.528942-1-dhowells@redhat.com> <20230209102954.528942-4-dhowells@redhat.com> To: Guenter Roeck Cc: dhowells@redhat.com, Jens Axboe , Al Viro , Christoph Hellwig , Matthew Wilcox , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Christoph Hellwig , John Hubbard Subject: Re: [PATCH v13 03/12] splice: Do splice read from a buffered file without using ITER_PIPE MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2416072.1676328192.1@warthog.procyon.org.uk> Date: Mon, 13 Feb 2023 22:43:12 +0000 Message-ID: <2416073.1676328192@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: EA238C001E X-Stat-Signature: h9s4pe1fzeerwau8ijgxwsphk3erqt3q X-HE-Tag: 1676328200-292189 X-HE-Meta: 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 2ZZvpE3S KOQ5IbwqJ3aw2wLPRoOH4SK+XfgBCOp8NAMeeoSZ9Azi+icvrJhZM4SHDOjrgs3nIgQke89bGKhqG+XHH7UoHCeJO6WPLvLPvJyzLqZrEUvCZMbj6k2vU7m8iNVO6PYJE2uoRLNArn81zF5kpNCp0jixyLKznjAcUPYb9/N/xi5CGdVjDXwn7lPvakAYvCLseX1QrXRo1AEeqz+NqFHuEsPydbsKOX8sTEwfv7lrK0UGTqm/9/oUDox9K0H1TvQT7lIAFTfzhhwcXgBZDjLvLqC7wxg== 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: Guenter Roeck wrote: > [ 4.660118] PC is at 0x0 > [ 4.660248] LR is at filemap_read_folio+0x17/0x4e Do you know what the filesystem is that's being read from? I think the problem is that there are a few filesystems/drivers that call generic_file_splice_read() but don't have a ->read_folio(). Now most of these can be made to call direct_splice_read() instead, leaving just coda, overlayfs and shmem. Coda and overlayfs can be made to pass the request down a layer. I'm about to look into shmem. David