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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 1FEFCC4338F for ; Mon, 9 Aug 2021 15:22:50 +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 8998960E52 for ; Mon, 9 Aug 2021 15:22:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 8998960E52 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:44312 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mD772-0007xq-8g for qemu-devel@archiver.kernel.org; Mon, 09 Aug 2021 11:22:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37940) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mD76B-0007H4-6T for qemu-devel@nongnu.org; Mon, 09 Aug 2021 11:21:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20040) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mD766-0003Jk-Dp for qemu-devel@nongnu.org; Mon, 09 Aug 2021 11:21:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628522507; 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=+81y37F7y6lU7HtjadpvTosGJlCp/L0jMgpQgQlv5PQ=; b=TnUtU7tLOAqbnV70I4SDAsZ579R8PpwdM3ABqEFDinlvnbeMQXw+HYtf/p5XkoJIF3qICc 2WnG76bPz/beNB/SdlJTcYHPx9qo8CVKore2C2Mnm7pOLUrZWsfmDCHZ+b8epZlVA+7oHj kOsipoaap0Rsw1zHjlHQgk7QOQbL+EA= 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-111-3zgN4OzwPZm8xUm3TZS7cA-1; Mon, 09 Aug 2021 11:21:44 -0400 X-MC-Unique: 3zgN4OzwPZm8xUm3TZS7cA-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 801CB802920 for ; Mon, 9 Aug 2021 15:21:43 +0000 (UTC) Received: from horse.redhat.com (unknown [10.22.10.79]) by smtp.corp.redhat.com (Postfix) with ESMTP id 174DA5C1D0; Mon, 9 Aug 2021 15:21:30 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 74186220261; Mon, 9 Aug 2021 11:21:30 -0400 (EDT) Date: Mon, 9 Aug 2021 11:21:30 -0400 From: Vivek Goyal To: Max Reitz Subject: Re: [PATCH v3 07/10] virtiofsd: Add lo_inode.fhandle Message-ID: References: <20210730150134.216126-1-mreitz@redhat.com> <20210730150134.216126-8-mreitz@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210730150134.216126-8-mreitz@redhat.com> 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: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.702, 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_H2=-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@redhat.com, qemu-devel@nongnu.org, Stefan Hajnoczi , "Dr . David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Jul 30, 2021 at 05:01:31PM +0200, Max Reitz wrote: > This new field is an alternative to lo_inode.fd: Either of the two must > be set. In case an O_PATH FD is needed for some lo_inode, it is either > taken from lo_inode.fd, if valid, or a temporary FD is opened with > open_by_handle_at(). > > Using a file handle instead of an FD has the advantage of keeping the > number of open file descriptors low. > > Because open_by_handle_at() requires a mount FD (i.e. a non-O_PATH FD > opened on the filesystem to which the file handle refers), but every > lo_fhandle only has a mount ID (as returned by name_to_handle_at()), we > keep a hash map of such FDs in mount_fds (mapping ID to FD). > get_file_handle(), which is added by a later patch, will ensure that > every mount ID for which we have generated a handle has a corresponding > entry in mount_fds. > > Signed-off-by: Max Reitz > Reviewed-by: Connor Kuehl > --- > tools/virtiofsd/passthrough_ll.c | 116 ++++++++++++++++++++++---- > tools/virtiofsd/passthrough_seccomp.c | 1 + > 2 files changed, 102 insertions(+), 15 deletions(-) > > diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c > index 292b7f7e27..487448d666 100644 > --- a/tools/virtiofsd/passthrough_ll.c > +++ b/tools/virtiofsd/passthrough_ll.c > @@ -88,8 +88,25 @@ struct lo_key { > uint64_t mnt_id; > }; > > +struct lo_fhandle { > + union { > + struct file_handle handle; > + char padding[sizeof(struct file_handle) + MAX_HANDLE_SZ]; > + }; > + int mount_id; > +}; > + > +/* Maps mount IDs to an FD that we can pass to open_by_handle_at() */ > +static GHashTable *mount_fds; > +pthread_rwlock_t mount_fds_lock = PTHREAD_RWLOCK_INITIALIZER; > + How about if we move this hash table inside "struct lo_data". That seems to be one global data structure keeping all the info. Also it can be cleaned up during lo_destroy(). Thanks Vivek