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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88490C6379F for ; Mon, 13 Feb 2023 22:44:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230164AbjBMWoH (ORCPT ); Mon, 13 Feb 2023 17:44:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230144AbjBMWoG (ORCPT ); Mon, 13 Feb 2023 17:44:06 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA0D01E1F6 for ; Mon, 13 Feb 2023 14:43:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1676328201; 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=bzDlkt0xr6Y1zO6bSP1oGY+akp9nAqPzy1Q1SZK++Bk722IucFpPJCQ4pydgZ0zAxwf87O tNbcK+F5FvMC0pFzonxg3+FoDIsrAQg3Y+ImMlc5ZUUZ2lXPJWBct/auIDcQ8RonD737Zk TtKRWbuXcwTF8pZnoU10JcESoe3wooQ= 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 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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