From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752015Ab2HPDDj (ORCPT ); Wed, 15 Aug 2012 23:03:39 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:51003 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750906Ab2HPDDg (ORCPT ); Wed, 15 Aug 2012 23:03:36 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Stanislav Kinsbursky Cc: tglx@linutronix.de, mingo@redhat.com, davem@davemloft.net, hpa@zytor.com, thierry.reding@avionic-design.de, bfields@redhat.com, eric.dumazet@gmail.com, xemul@parallels.com, neilb@suse.de, netdev@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, paul.gortmaker@windriver.com, viro@zeniv.linux.org.uk, gorcunov@openvz.org, akpm@linux-foundation.org, tim.c.chen@linux.intel.com, devel@openvz.org References: <20120815161141.7598.16682.stgit@localhost.localdomain> Date: Wed, 15 Aug 2012 20:03:24 -0700 In-Reply-To: <20120815161141.7598.16682.stgit@localhost.localdomain> (Stanislav Kinsbursky's message of "Wed, 15 Aug 2012 20:21:56 +0400") Message-ID: <87y5lf7d37.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=98.207.153.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/t0CzVJxXRoavBvoqVbMG4AvnaIQMjKug= X-SA-Exim-Connect-IP: 98.207.153.68 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.1 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -3.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa05 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_XMDrugObfuBody_08 obfuscated drug references X-Spam-DCC: XMission; sa05 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Stanislav Kinsbursky X-Spam-Relay-Country: Subject: Re: [RFC PATCH 0/5] net: socket bind to file descriptor introduced X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Fri, 06 Aug 2010 16:31:04 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Stanislav Kinsbursky writes: > This patch set introduces new socket operation and new system call: > sys_fbind(), which allows to bind socket to opened file. > File to bind to can be created by sys_mknod(S_IFSOCK) and opened by > open(O_PATH). > > This system call is especially required for UNIX sockets, which has name > lenght limitation. > > The following series implements... Hmm. I just realized this patchset is even sillier than I thought. Stanislav is the problem you are ultimately trying to solve nfs clients in a container connecting to the wrong user space rpciod? Aka net/sunrpc/xprtsock.c:xs_setup_local only taking an absolute path and then creating a delayed work item to actually open the unix domain socket? The straight correct and straight forward thing to do appears to be: - Capture the root from current->fs in xs_setup_local. - In xs_local_finish_connect change current->fs.root to the captured version of root before kernel_connect, and restore current->fs.root after kernel_connect. It might not be a bad idea to implement open on unix domain sockets in a filesystem as create(AF_LOCAL)+connect() which would allow you to replace __sock_create + kernel_connect with a simple file_open_root. But I think the simple scheme of: struct path old_root; old_root = current->fs.root; kernel_connect(...); current->fs.root = old_root; Is more than sufficient and will remove the need for anything except a purely local change to get nfs clients to connect from containers. Eric