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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]:33746 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kZg1A-0008U8-2o for qemu-devel@archiver.kernel.org; Mon, 02 Nov 2020 15:01:28 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:34746) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kZfxT-0003VX-3n for qemu-devel@nongnu.org; Mon, 02 Nov 2020 14:57:39 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:56250) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kZfxP-0002JZ-Hf for qemu-devel@nongnu.org; Mon, 02 Nov 2020 14:57:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604347054; 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: in-reply-to:in-reply-to:references:references; bh=Dsdj41DT4PLyqjl/hukCgshvrwrFxo0EoUsW+ilKs0o=; b=JgN2hjrOsl/SnwdA6rbikTvJgHNkco6ivJ7N6O6RCTLlq1YI8b3KszqxlgkHIerocTI13B 9VQRSCnu4yzGBV8Y49yducfrELyNLES8Jwl93cXRr4CgmhoFDYT8rm+Vjrg2gtPXk2/ttQ eJbN7ThmS+pCJouVNtkwNNqGVFaboOc= 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-473-Bx-hNxqJNFK2VGofcWafJQ-1; Mon, 02 Nov 2020 14:57:33 -0500 X-MC-Unique: Bx-hNxqJNFK2VGofcWafJQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 23B58805F08; Mon, 2 Nov 2020 19:57:32 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-114-142.ams2.redhat.com [10.36.114.142]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8E0CD1002C0A; Mon, 2 Nov 2020 19:57:30 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, peterx@redhat.com, philmd@redhat.com, zhangjiachen.jaycee@bytedance.com, mreitz@redhat.com Subject: [PULL 10/12] virtiofsd: Announce sub-mount points Date: Mon, 2 Nov 2020 19:56:55 +0000 Message-Id: <20201102195657.219501-11-dgilbert@redhat.com> In-Reply-To: <20201102195657.219501-1-dgilbert@redhat.com> References: <20201102195657.219501-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/02 01:33:03 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_NONE=-0.0001, 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: stefanha@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Max Reitz Whenever we encounter a directory with an st_dev or mount ID that differs from that of its parent, we set the FUSE_ATTR_SUBMOUNT flag so the guest can create a submount for it. We only need to do so in lo_do_lookup(). The following functions return a fuse_attr object: - lo_create(), though fuse_reply_create(): Calls lo_do_lookup(). - lo_lookup(), though fuse_reply_entry(): Calls lo_do_lookup(). - lo_mknod_symlink(), through fuse_reply_entry(): Calls lo_do_lookup(). - lo_link(), through fuse_reply_entry(): Creating a link cannot create a submount, so there is no need to check for it. - lo_getattr(), through fuse_reply_attr(): Announcing submounts when the node is first detected (at lookup) is sufficient. We do not need to return the submount attribute later. - lo_do_readdir(), through fuse_add_direntry_plus(): Calls lo_do_lookup(). Make announcing submounts optional, so submounts are only announced to the guest with the announce_submounts option. Some users may prefer the current behavior, so that the guest learns nothing about the host mount structure. (announce_submounts is force-disabled when the guest does not present the FUSE_SUBMOUNTS capability, or when there is no statx().) Signed-off-by: Max Reitz Reviewed-by: Stefan Hajnoczi Message-Id: <20201102161859.156603-6-mreitz@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/helper.c | 1 + tools/virtiofsd/passthrough_ll.c | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/tools/virtiofsd/helper.c b/tools/virtiofsd/helper.c index ae1b22e4a6..75ac48dec2 100644 --- a/tools/virtiofsd/helper.c +++ b/tools/virtiofsd/helper.c @@ -190,6 +190,7 @@ void fuse_cmdline_help(void) " retain/discard O_DIRECT flags passed down\n" " to virtiofsd from guest applications.\n" " default: no_allow_direct_io\n" + " -o announce_submounts Announce sub-mount points to the guest\n" ); } diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 34d107975f..ec1008bceb 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -40,6 +40,7 @@ #include "fuse_virtio.h" #include "fuse_log.h" #include "fuse_lowlevel.h" +#include "standard-headers/linux/fuse.h" #include #include #include @@ -167,6 +168,7 @@ struct lo_data { int readdirplus_set; int readdirplus_clear; int allow_direct_io; + int announce_submounts; bool use_statx; struct lo_inode root; GHashTable *inodes; /* protected by lo->mutex */ @@ -207,6 +209,7 @@ static const struct fuse_opt lo_opts[] = { { "no_readdirplus", offsetof(struct lo_data, readdirplus_clear), 1 }, { "allow_direct_io", offsetof(struct lo_data, allow_direct_io), 1 }, { "no_allow_direct_io", offsetof(struct lo_data, allow_direct_io), 0 }, + { "announce_submounts", offsetof(struct lo_data, announce_submounts), 1 }, FUSE_OPT_END }; static bool use_syslog = false; @@ -601,6 +604,20 @@ static void lo_init(void *userdata, struct fuse_conn_info *conn) fuse_log(FUSE_LOG_DEBUG, "lo_init: disabling readdirplus\n"); conn->want &= ~FUSE_CAP_READDIRPLUS; } + + if (!(conn->capable & FUSE_CAP_SUBMOUNTS) && lo->announce_submounts) { + fuse_log(FUSE_LOG_WARNING, "lo_init: Cannot announce submounts, client " + "does not support it\n"); + lo->announce_submounts = false; + } + +#ifndef CONFIG_STATX + if (lo->announce_submounts) { + fuse_log(FUSE_LOG_WARNING, "lo_init: Cannot announce submounts, there " + "is no statx()\n"); + lo->announce_submounts = false; + } +#endif } static void lo_getattr(fuse_req_t req, fuse_ino_t ino, @@ -877,6 +894,11 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name, goto out_err; } + if (S_ISDIR(e->attr.st_mode) && lo->announce_submounts && + (e->attr.st_dev != dir->key.dev || mnt_id != dir->key.mnt_id)) { + e->attr_flags |= FUSE_ATTR_SUBMOUNT; + } + inode = lo_find(lo, &e->attr, mnt_id); if (inode) { close(newfd); -- 2.28.0