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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1CF0ECE58E for ; Tue, 15 Oct 2019 09:21:40 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B04272064B for ; Tue, 15 Oct 2019 09:21:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B04272064B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38416 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iKJ1P-00085Y-QK for qemu-devel@archiver.kernel.org; Tue, 15 Oct 2019 05:21:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36610) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iKJ0l-0007W2-N5 for qemu-devel@nongnu.org; Tue, 15 Oct 2019 05:21:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iKJ0k-0000sk-6a for qemu-devel@nongnu.org; Tue, 15 Oct 2019 05:20:59 -0400 Received: from 6.mo69.mail-out.ovh.net ([46.105.50.107]:50063) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iKJ0j-0000qU-Uh for qemu-devel@nongnu.org; Tue, 15 Oct 2019 05:20:58 -0400 Received: from player698.ha.ovh.net (unknown [10.109.146.168]) by mo69.mail-out.ovh.net (Postfix) with ESMTP id 202296C058 for ; Tue, 15 Oct 2019 11:20:48 +0200 (CEST) Received: from kaod.org (lns-bzn-46-82-253-208-248.adsl.proxad.net [82.253.208.248]) (Authenticated sender: groug@kaod.org) by player698.ha.ovh.net (Postfix) with ESMTPSA id 26D5DAF72600; Tue, 15 Oct 2019 09:20:43 +0000 (UTC) Date: Tue, 15 Oct 2019 11:20:39 +0200 From: Greg Kurz To: Christian Schoenebeck Subject: Re: [Qemu-devel] [PATCH v7 0/3] 9p: Fix file ID collisions Message-ID: <20191015112039.620997e3@bahia.lan> In-Reply-To: <2456208.kOTvEbKLdM@silver> References: <1590425.yRI6RxI3rl@silver> <20191008111459.048e659f@bahia.lan> <2456208.kOTvEbKLdM@silver> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Ovh-Tracer-Id: 10335761147260934464 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedufedrjeefgdduhecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 46.105.50.107 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Stefan Hajnoczi , "Daniel P. =?UTF-8?B?QmVycmFuZ8Op?=" , qemu-devel@nongnu.org, Antonios Motakis , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 08 Oct 2019 14:05:28 +0200 Christian Schoenebeck wrote: > > I wonder though whether virtio-fs suffers from the same file ID collisions > problem when sharing multiple file systems. > I gave a try and it seems that virtio-fs might expose the inode numbers from different devices in the host, unvirtualized AND with the same device in the guest: # mkdir -p /var/tmp/virtio-fs/proc # mount --bind /proc /var/tmp/virtio-fs/proc # virtiofsd -o vhost_user_socket=/tmp/vhostqemu -o source=/var/tmp/virtio-fs -o cache=always and then started QEMU with: -chardev socket,id=char0,path=/tmp/vhostqemu \ -device vhost-user-fs-pci,queue-size=1024,chardev=char0,tag=myfs \ -m 4G -object memory-backend-file,id=mem,size=4G,mem-path=/dev/shm,share=on \ -numa node,memdev=mem In the host: $ stat /var/tmp/virtio-fs File: /var/tmp/virtio-fs Size: 4096 Blocks: 8 IO Block: 4096 directory Device: fd00h/64768d Inode: 787796 Links: 4 Access: (0775/drwxrwxr-x) Uid: ( 1000/ greg) Gid: ( 1000/ greg) Context: unconfined_u:object_r:user_tmp_t:s0 Access: 2019-10-15 11:08:52.070080922 +0200 Modify: 2019-10-15 11:02:09.887404446 +0200 Change: 2019-10-15 11:02:09.887404446 +0200 Birth: 2019-10-13 19:13:04.009699354 +0200 [greg@bahia ~]$ stat /var/tmp/virtio-fs/FOO File: /var/tmp/virtio-fs/FOO Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: fd00h/64768d Inode: 790740 Links: 1 Access: (0664/-rw-rw-r--) Uid: ( 1000/ greg) Gid: ( 1000/ greg) Context: unconfined_u:object_r:user_tmp_t:s0 Access: 2019-10-15 11:02:09.888404448 +0200 Modify: 2019-10-15 11:02:09.888404448 +0200 Change: 2019-10-15 11:02:09.888404448 +0200 Birth: 2019-10-15 11:02:09.887404446 +0200 [greg@bahia ~]$ stat /var/tmp/virtio-fs/proc/fs File: /var/tmp/virtio-fs/proc/fs Size: 0 Blocks: 0 IO Block: 1024 directory Device: 4h/4d Inode: 4026531845 Links: 5 Access: (0555/dr-xr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:proc_t:s0 Access: 2019-10-01 14:50:09.223233901 +0200 Modify: 2019-10-01 14:50:09.223233901 +0200 Change: 2019-10-01 14:50:09.223233901 +0200 Birth: - In the guest: [greg@localhost ~]$ stat /mnt File: /mnt Size: 4096 Blocks: 8 IO Block: 4096 directory Device: 2dh/45d Inode: 787796 Links: 4 Access: (0775/drwxrwxr-x) Uid: ( 1000/ greg) Gid: ( 1000/ greg) Context: system_u:object_r:unlabeled_t:s0 Access: 2019-10-15 11:08:52.070080922 +0200 Modify: 2019-10-15 11:02:09.887404446 +0200 Change: 2019-10-15 11:02:09.887404446 +0200 Birth: - [greg@localhost ~]$ stat /mnt/FOO File: /mnt/FOO Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: 2dh/45d Inode: 790740 Links: 1 Access: (0664/-rw-rw-r--) Uid: ( 1000/ greg) Gid: ( 1000/ greg) Context: system_u:object_r:unlabeled_t:s0 Access: 2019-10-15 11:02:09.888404448 +0200 Modify: 2019-10-15 11:02:09.888404448 +0200 Change: 2019-10-15 11:02:09.888404448 +0200 Birth: - [greg@localhost ~]$ stat /mnt/proc/fs File: /mnt/proc/fs Size: 0 Blocks: 0 IO Block: 1024 directory Device: 2dh/45d Inode: 4026531845 Links: 5 Access: (0555/dr-xr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Context: system_u:object_r:unlabeled_t:s0 Access: 2019-10-01 14:50:09.223233901 +0200 Modify: 2019-10-01 14:50:09.223233901 +0200 Change: 2019-10-01 14:50:09.223233901 +0200 Birth: - Unless I'm missing something, it seems that "virtio-fs" has the same issue we had on 9pfs before Christian's patches... :-\ -- Greg