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 A86EEC7EE29 for ; Fri, 2 Jun 2023 11:45:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234832AbjFBLp5 (ORCPT ); Fri, 2 Jun 2023 07:45:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35594 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229470AbjFBLpy (ORCPT ); Fri, 2 Jun 2023 07:45:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A0D6194 for ; Fri, 2 Jun 2023 04:45:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685706307; 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=0/yzPRRzgr0a2u6l5HBVBgW8iyZpj+2he0Zb6/uXfoE=; b=CbLtjryOZw1QeR+KIknKExGKbAFL5zoWcDwqe9QdHp/8epSC9UPXINCRbmlL81bvEf463i r85JvZpxVY6NPoL8zEgzMeNhLd0sdK+nXzRCId5HJj9l/eofIfRLY8069hoix+9LFDVIbr r61tMnHOzJDGPPL+/tyllexk9byPtIs= 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-614-18pN8u9yNt6Rjg29hrPxFQ-1; Fri, 02 Jun 2023 07:45:00 -0400 X-MC-Unique: 18pN8u9yNt6Rjg29hrPxFQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 55AD9381D4ED; Fri, 2 Jun 2023 11:44:59 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.182]) by smtp.corp.redhat.com (Postfix) with ESMTP id 19CB1C154D7; Fri, 2 Jun 2023 11:44:56 +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: References: <20230524153311.3625329-1-dhowells@redhat.com> <20230524153311.3625329-10-dhowells@redhat.com> <20230526180844.73745d78@kernel.org> <499791.1685485603@warthog.procyon.org.uk> <832277.1685630048@warthog.procyon.org.uk> <909595.1685639680@warthog.procyon.org.uk> <20230601212043.720f85c2@kernel.org> <952877.1685694220@warthog.procyon.org.uk> To: Linus Torvalds Cc: dhowells@redhat.com, Jakub Kicinski , netdev@vger.kernel.org, "David S. Miller" , Eric Dumazet , Paolo Abeni , Willem de Bruijn , David Ahern , Matthew Wilcox , Jens Axboe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chuck Lever , Boris Pismenny , John Fastabend , Christoph Hellwig Subject: Re: Bug in short splice to socket? MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <1227121.1685706296.1@warthog.procyon.org.uk> Date: Fri, 02 Jun 2023 12:44:56 +0100 Message-ID: <1227123.1685706296@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > Do what I already suggested: making SPLICE_F_MORE reflect reality. I'm trying to. I need MSG_MORE to behave sensibly for what I want. What I have signals SPLICE_F_MORE (and thus MSG_MORE) as long as we haven't yet read enough data to fulfill the request - and will break out of the loop if we get a zero-length read. But this causes a change in behaviour because we then leave the protocol having seen MSG_MORE set where it didn't previously see that. This causes "tls -r tls.12_aes_gcm.multi_chunk_sendfile" on the TLS kselftest to fail. Now, if we're fine with the change in behaviour, I can make the selftest observe the short sendfile() and cancel MSG_MORE itself - but that's just a test program. So that's the question: Do I have to maintain the current behaviour for the short-splice case? David