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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 3EB79C433F5 for ; Tue, 8 Mar 2022 07:12:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IYbuICA/X2T0MBgKeuWaZurAzzwr+XUnK67HpqkEe9w=; b=L3pf44yI1FkxQ2u6XXprvL6v4L Rp3iy2LU5cSq52ynd1lO+kuoxnNUhcysVyyjQpavulR8Tl1X6xu2LmpicS47IppQeyfJ74+TawGlq ymc76AfegAHrsAvl7YZv/ZtRAFrkEXVLUPJKZ8o/+j/v4uz0gOrRwHK/pqKxaL9nYKfRnFqUw80a1 Iinmv2PATBRd6yagpGvtCTq4fGcwpGg0tbTVuxEsRazB8irJcfwoxvSdG0bD/tFeCwDQ9ZObKULOd zQ44eCqcYbINfz9UZkmdY0pCygc1MDDDkxCq4VIAny22AV8jrD6ZSO7vQIr3o5QVRsKnDPxOhQ26i 0LeF6jCQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRU1K-0030cF-KX; Tue, 08 Mar 2022 07:12:34 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRU1H-0030bM-Ua for linux-nvme@lists.infradead.org; Tue, 08 Mar 2022 07:12:33 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id AA5B668AFE; Tue, 8 Mar 2022 08:12:27 +0100 (CET) Date: Tue, 8 Mar 2022 08:12:27 +0100 From: Christoph Hellwig To: Mingbao Sun Cc: Christoph Hellwig , Keith Busch , Jens Axboe , Sagi Grimberg , Chaitanya Kulkarni , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, tyler.sun@dell.com, ping.gan@dell.com, yanxiu.cai@dell.com, libin.zhang@dell.com, ao.sun@dell.com Subject: Re: [PATCH 2/2] nvme-tcp: support specifying the congestion-control Message-ID: <20220308071227.GB24575@lst.de> References: <20220304092754.2721-1-sunmingbao@tom.com> <20220304092754.2721-3-sunmingbao@tom.com> <20220304162032.GA12250@lst.de> <20220305150915.00006b44@tom.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220305150915.00006b44@tom.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220307_231232_154742_17013EB1 X-CRM114-Status: GOOD ( 18.39 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Sat, Mar 05, 2022 at 03:09:15PM +0800, Mingbao Sun wrote: > Well, actually I did have thought whether the calling of network API > here is proper. Since I did find that there is no call to APIs of > PCI/RDMA/TCP in fabrics.c. Yes - for a good reason. Without networking support your patch won't even compile (both the host and target side). > But I hope the following could make a defense for it: > > Anyway, we need to validate the tcp_congestion passed in from > user-space, right? Do we? It seems like no one else really calls this routine to verify things. In fact it has no modular users at all in the current tree. > The role of nvmf_parse_options is similar to that of > drivers/nvme/target/configfs.c from the target side. > And both of them can not avoid handling specific options of the > sub-classes (e.g., NVMF_OPT_HDR_DIGEST, NVMF_OPT_TOS, NVMF_OPT_KATO). NVMF_OPT_KATO is completely generic, but yes, there other two are transport specific. None of them calls out into other modules that would need dependecies, though. I'm also a little concerned that no other in kernel user like iSCSI, NBD or NFS has any code like this.