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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 6D139C433E0 for ; Mon, 22 Feb 2021 14:49:53 +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 CC29364E32 for ; Mon, 22 Feb 2021 14:49:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC29364E32 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:60854 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lECX1-0004pt-NE for qemu-devel@archiver.kernel.org; Mon, 22 Feb 2021 09:49:51 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51262) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lECUt-0002vJ-Un for qemu-devel@nongnu.org; Mon, 22 Feb 2021 09:47:40 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:60126) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lECUq-0006fR-Rw for qemu-devel@nongnu.org; Mon, 22 Feb 2021 09:47:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614005255; 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=KDB8RW+9ybnr/1S5BXvxjoPvCUPzsMd5yZFcY6xLmOY=; b=XJ7cKVihcEiW4raKXER5sx3xkLdvwMbsqpEjtsxwc6p/Mk1jErF3xB+BfrIdvMTyQMSjI3 X6OsTRRhv/v9Xh4p5lWAS9cjwd9sSdOE4TJEnYT+nlB+9EhTflLBi5/eB/1jiDEhkpS8Sc HUoo7k/aTZeqUTBWTTvI/P4pP6mV6OY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-355-uNRZnhjhPVWd6pD3Xfa9hQ-1; Mon, 22 Feb 2021 09:47:33 -0500 X-MC-Unique: uNRZnhjhPVWd6pD3Xfa9hQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DAA44107ACF3; Mon, 22 Feb 2021 14:47:31 +0000 (UTC) Received: from horse.redhat.com (ovpn-115-91.rdu2.redhat.com [10.10.115.91]) by smtp.corp.redhat.com (Postfix) with ESMTP id 12C695C290; Mon, 22 Feb 2021 14:47:25 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 8489422054F; Mon, 22 Feb 2021 09:47:24 -0500 (EST) Date: Mon, 22 Feb 2021 09:47:24 -0500 From: Vivek Goyal To: Miklos Szeredi Subject: Re: [PATCH v2 0/3] virtiofsd: Add options to enable/disable posix acl Message-ID: <20210222144724.GC13715@redhat.com> References: <20210217233046.81418-1-vgoyal@redhat.com> <87pn0wgtsx.fsf@suse.de> <20210219143403.GA3270@redhat.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vgoyal@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: virtio-fs-list , Stefan Hajnoczi , Luis Henriques , "Dr. David Alan Gilbert" , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Feb 19, 2021 at 04:55:06PM +0100, Miklos Szeredi wrote: > On Fri, Feb 19, 2021 at 3:34 PM Vivek Goyal wrote: > > > > On Fri, Feb 19, 2021 at 11:50:54AM +0000, Luis Henriques wrote: > > > Vivek Goyal writes: > > > > > > > Hi, > > > > > > > > This is V2 of the patches. Changes since v1 are. > > > > > > > > - Rebased on top of latest master. > > > > - Took care of Miklos's comments to block acl xattrs if user > > > > explicitly disabled posix acl. > > > > > > > > Luis Henriques reported that fstest generic/099 fails with virtiofs. > > > > Little debugging showed that we don't enable acl support. So this > > > > patch series provides option to enable/disable posix acl support. By > > > > default it is disabled. > > > > > > > > I have run blogbench and pjdfstests with posix acl enabled and > > > > things work fine. > > > > > > > > Luis, can you please apply these patches, and run virtiofsd with > > > > "-o posix_acl" and see if it fixes the failure you are seeing. I > > > > ran the steps you provided manually and it fixes the issue for > > > > me. > > > > > > Sorry for the delay. I've finally tested these patches and they indeed > > > fix the problem I reported. My only question about this fix is why is > > > this option not enabled by default, since this is the documented behavior > > > in acl(5) and umask(2)? In fact, why is this an option at all? > > > > You mean why to not enable acl by default? > > > > I am concerned about performance drop this can lead to because extra > > GETXATTR(system.posix_acl_*) messages which will trigger if acls are enabled. > > And not all users might require these. That's why I preferred to not enable > > acl by default. Those who need it can enable it explicitly. > > > > Another example is xattr support. Due to performance concerns, we don't > > enable xattrs by default either. > > Actually generic xattr is much worse, since there's no caching for > them currently, as opposed to posix acls, which are cached both when > positive and negative. > > If we enable ACL by default in case xattrs are enabled, we should be > safe, I think. Hi Miklos, Ok, this sounds reasonable. I am running some quick tests and if I don't notice any serious performance regression, I will respin my patch. > Having an option to disable acls still makes sense, > but it's an optional plus. Agreed. If there are no serious negative performance issues with enabling ACL, then an option to disable is an optional plus. May be I will drop this for now and add this when somebody needs an option to disable ACL. Thanks Vivek From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 22 Feb 2021 09:47:24 -0500 From: Vivek Goyal Message-ID: <20210222144724.GC13715@redhat.com> References: <20210217233046.81418-1-vgoyal@redhat.com> <87pn0wgtsx.fsf@suse.de> <20210219143403.GA3270@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Virtio-fs] [PATCH v2 0/3] virtiofsd: Add options to enable/disable posix acl List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Miklos Szeredi Cc: virtio-fs-list , qemu-devel@nongnu.org On Fri, Feb 19, 2021 at 04:55:06PM +0100, Miklos Szeredi wrote: > On Fri, Feb 19, 2021 at 3:34 PM Vivek Goyal wrote: > > > > On Fri, Feb 19, 2021 at 11:50:54AM +0000, Luis Henriques wrote: > > > Vivek Goyal writes: > > > > > > > Hi, > > > > > > > > This is V2 of the patches. Changes since v1 are. > > > > > > > > - Rebased on top of latest master. > > > > - Took care of Miklos's comments to block acl xattrs if user > > > > explicitly disabled posix acl. > > > > > > > > Luis Henriques reported that fstest generic/099 fails with virtiofs. > > > > Little debugging showed that we don't enable acl support. So this > > > > patch series provides option to enable/disable posix acl support. By > > > > default it is disabled. > > > > > > > > I have run blogbench and pjdfstests with posix acl enabled and > > > > things work fine. > > > > > > > > Luis, can you please apply these patches, and run virtiofsd with > > > > "-o posix_acl" and see if it fixes the failure you are seeing. I > > > > ran the steps you provided manually and it fixes the issue for > > > > me. > > > > > > Sorry for the delay. I've finally tested these patches and they indeed > > > fix the problem I reported. My only question about this fix is why is > > > this option not enabled by default, since this is the documented behavior > > > in acl(5) and umask(2)? In fact, why is this an option at all? > > > > You mean why to not enable acl by default? > > > > I am concerned about performance drop this can lead to because extra > > GETXATTR(system.posix_acl_*) messages which will trigger if acls are enabled. > > And not all users might require these. That's why I preferred to not enable > > acl by default. Those who need it can enable it explicitly. > > > > Another example is xattr support. Due to performance concerns, we don't > > enable xattrs by default either. > > Actually generic xattr is much worse, since there's no caching for > them currently, as opposed to posix acls, which are cached both when > positive and negative. > > If we enable ACL by default in case xattrs are enabled, we should be > safe, I think. Hi Miklos, Ok, this sounds reasonable. I am running some quick tests and if I don't notice any serious performance regression, I will respin my patch. > Having an option to disable acls still makes sense, > but it's an optional plus. Agreed. If there are no serious negative performance issues with enabling ACL, then an option to disable is an optional plus. May be I will drop this for now and add this when somebody needs an option to disable ACL. Thanks Vivek