From patchwork Fri Jun 4 16:13:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 12300259 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_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D1743C4743D for ; Fri, 4 Jun 2021 17:11:20 +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 849736140C for ; Fri, 4 Jun 2021 17:11:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 849736140C 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]:47154 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lpDLr-00040g-OP for qemu-devel@archiver.kernel.org; Fri, 04 Jun 2021 13:11:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52374) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lpCSN-00055j-Hp for qemu-devel@nongnu.org; Fri, 04 Jun 2021 12:13:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:22587) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lpCSI-00040v-Oo for qemu-devel@nongnu.org; Fri, 04 Jun 2021 12:13:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622823234; 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: content-transfer-encoding:content-transfer-encoding; bh=2LcyGfNOMzt4IC4P0p20tqVvDSo/ZQAZLOIc2I9Y1Gc=; b=DivFu5gQZTN14isbQSlXe9e2yp42ni+YNkdQjRcWqdMQssQ5WoDWrPlOy4dOOEMF5rHXdH qY2VwqLJpvyajYuXZGhH278HvLiqTW8SIqltkHBUSDn/SultYUtVkbAO+rQ8nzQ86vnjbT EgUDzoIgE8NB16UEYI37xhyt0rHzW9Y= 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-251-zcNeKLy3O4WdCWiGFp_zvQ-1; Fri, 04 Jun 2021 12:13:51 -0400 X-MC-Unique: zcNeKLy3O4WdCWiGFp_zvQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CC000180FD6D for ; Fri, 4 Jun 2021 16:13:50 +0000 (UTC) Received: from localhost (ovpn-114-199.ams2.redhat.com [10.36.114.199]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2EDAF5D74B; Fri, 4 Jun 2021 16:13:38 +0000 (UTC) From: Max Reitz To: qemu-devel@nongnu.org, virtio-fs@redhat.com Subject: [PATCH 0/9] virtiofsd: Allow using file handles instead of O_PATH FDs Date: Fri, 4 Jun 2021 18:13:28 +0200 Message-Id: <20210604161337.16048-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.373, 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_H4=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: "Dr . David Alan Gilbert" , Stefan Hajnoczi , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hi, This is the C virtiofsd equivalent to https://gitlab.com/virtio-fs/virtiofsd-rs/-/merge_requests/26. As such, the summary is pretty much the same: Storing an O_PATH file descriptor in every lo_inode object means we have a lot of FDs open, which is sometimes bad. This series adds an option (-o inode_file_handles) that will make virtiofsd attempt to generate a file handle for new inodes and store that instead of an FD. When an FD is needed for a given inode, we open the handle. To accomplish this, lo_inode.fd is should not be accessed directly anymore, but only through helper functions (mainly lo_inode_fd() and lo_inode_open()). A TempFd object is added to hide the difference between FDs that are bound to the lo_inode object (and so need not be closed after use) and temporary FDs from open_by_handle_at() (which do need to be closed after use). To prevent the problem I spent a long time talking about (if we don’t have an FD open for every inode, the inode can be deleted, its ID reused, and then the lookup in lo_data.inodes will find the old deleted inode), patch 7 adds a second hash table lo_data.inodes_by_handle that maps file handles to lo_inode objects. (Because file handles include a generation ID, so we can discern between the old and the new inode.) Patch 9 is completely optional, but I just really felt compelled to write it. Max Reitz (9): virtiofsd: Add TempFd structure virtiofsd: Use lo_inode_open() instead of openat() virtiofsd: Add lo_inode_fd() helper virtiofsd: Let lo_fd() return a TempFd virtiofsd: Let lo_inode_open() return a TempFd virtiofsd: Add lo_inode.fhandle virtiofsd: Add inodes_by_handle hash table virtiofsd: Optionally fill lo_inode.fhandle virtiofsd: Add lazy lo_do_find() tools/virtiofsd/helper.c | 3 + tools/virtiofsd/passthrough_ll.c | 809 +++++++++++++++++++++----- tools/virtiofsd/passthrough_seccomp.c | 2 + 3 files changed, 667 insertions(+), 147 deletions(-) Reviewed-by: Connor Kuehl