From patchwork Tue Feb 23 22:52:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 12101011 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=-13.5 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,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 DCF92C433DB for ; Tue, 23 Feb 2021 22:54:12 +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 6183364E5C for ; Tue, 23 Feb 2021 22:54:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6183364E5C 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]:36054 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lEgZH-0001sW-6d for qemu-devel@archiver.kernel.org; Tue, 23 Feb 2021 17:54:11 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:47862) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lEgYO-000130-A8 for qemu-devel@nongnu.org; Tue, 23 Feb 2021 17:53:16 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:34741) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lEgYM-0001kC-KC for qemu-devel@nongnu.org; Tue, 23 Feb 2021 17:53:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614120794; 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=t5/fBnrUenbwfhmNYwbT1HfUIR5I2D65z+c3OnmaG1c=; b=aXwNuqXCzrwSgXkvSJJCUY5gLjY9aHQhTl/iJ+u1uaMEjlOzbxn49fJ2/7anZ0s5HqMjTp N0mMdIH3Af5iMqxJ1tY7QekuI0nbzovWcpCfgVjnIpG7rKpwGQ9mOcuo4HnKc7ErgTjPWX 5cfUMMj6GZFl3NHsVPWS1Fgpywe+vhI= 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-187-XGH3yBTgNgWJeeg6_FyVQw-1; Tue, 23 Feb 2021 17:53:09 -0500 X-MC-Unique: XGH3yBTgNgWJeeg6_FyVQw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C06D680196C; Tue, 23 Feb 2021 22:53:08 +0000 (UTC) Received: from horse.redhat.com (ovpn-117-211.rdu2.redhat.com [10.10.117.211]) by smtp.corp.redhat.com (Postfix) with ESMTP id BEF865D9D3; Tue, 23 Feb 2021 22:52:59 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 121D9223D99; Tue, 23 Feb 2021 17:52:59 -0500 (EST) From: Vivek Goyal To: qemu-devel@nongnu.org, virtio-fs@redhat.com Subject: [PATCH v3 2/2] virtiofsd: Enable posix_acls by default if xattrs are enabled Date: Tue, 23 Feb 2021 17:52:50 -0500 Message-Id: <20210223225250.23945-3-vgoyal@redhat.com> In-Reply-To: <20210223225250.23945-1-vgoyal@redhat.com> References: <20210223225250.23945-1-vgoyal@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 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 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: lhenriques@suse.de, stefanha@redhat.com, dgilbert@redhat.com, vgoyal@redhat.com, miklos@szeredi.hu Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Fuse protocl wants file server to opt in for FUSE_POSIX_ACL if posix acls are to be enabled. Right now virtiofsd does not enable it. This patch opts in for FUSE_POSIX_ACL if xattr support is enabled. When parent directory has default acl and a file is created in that directory, then umask is ignored and final file permissions are determined using default acl instead. (man 2 umask). Currently, fuse applies the umask and sends modified mode in create request accordingly. fuse server can set FUSE_DONT_MASK and tell fuse client to not apply umask and fuse server will take care of it as needed. With posix acls enabled, requirement will be that we want umask to determine final file mode if parent directory does not have default acl. So if posix acls are enabled, opt in for FUSE_DONT_MASK. virtiofsd will set umask of the thread doing file creation. And host kernel should use that umask if parent directory does not have default acls, otherwise umask does not take affect. Miklos mentioned that we already call unshare(CLONE_FS) for every thread. That means umask has now become property of per thread and it should be ok to manipulate it in file creation path. So this patch also opts in for FUSE_DONT_MASK if posix acls are enabled and changes umask to caller umask before file creation and restores original umask after file creation is done. This should fix fstest generic/099. Reported-by: Luis Henriques Signed-off-by: Vivek Goyal Reviewed-by: Stefan Hajnoczi --- tools/virtiofsd/passthrough_ll.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 58d24c0010..0d62c9a889 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -120,6 +120,7 @@ struct lo_inode { struct lo_cred { uid_t euid; gid_t egid; + mode_t umask; }; enum { @@ -169,6 +170,8 @@ struct lo_data { /* An O_PATH file descriptor to /proc/self/fd/ */ int proc_self_fd; int user_killpriv_v2, killpriv_v2; + /* If set, virtiofsd is responsible for setting umask during creation */ + bool change_umask; }; static const struct fuse_opt lo_opts[] = { @@ -661,6 +664,13 @@ static void lo_init(void *userdata, struct fuse_conn_info *conn) conn->want &= ~FUSE_CAP_HANDLE_KILLPRIV_V2; lo->killpriv_v2 = 0; } + + /* If xattrs are enabled, enable ACL support by default */ + if (lo->xattr && conn->capable & FUSE_CAP_POSIX_ACL) { + fuse_log(FUSE_LOG_DEBUG, "lo_init: enabling posix_acls\n"); + conn->want |= FUSE_CAP_POSIX_ACL | FUSE_CAP_DONT_MASK; + lo->change_umask = true; + } } static void lo_getattr(fuse_req_t req, fuse_ino_t ino, @@ -1075,7 +1085,8 @@ static void lo_lookup(fuse_req_t req, fuse_ino_t parent, const char *name) * ownership of caller. * TODO: What about selinux context? */ -static int lo_change_cred(fuse_req_t req, struct lo_cred *old) +static int lo_change_cred(fuse_req_t req, struct lo_cred *old, + bool change_umask) { int res; @@ -1095,11 +1106,14 @@ static int lo_change_cred(fuse_req_t req, struct lo_cred *old) return errno_save; } + if (change_umask) { + old->umask = umask(req->ctx.umask); + } return 0; } /* Regain Privileges */ -static void lo_restore_cred(struct lo_cred *old) +static void lo_restore_cred(struct lo_cred *old, bool restore_umask) { int res; @@ -1114,6 +1128,9 @@ static void lo_restore_cred(struct lo_cred *old) fuse_log(FUSE_LOG_ERR, "setegid(%u): %m\n", old->egid); exit(1); } + + if (restore_umask) + umask(old->umask); } static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent, @@ -1138,7 +1155,7 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent, return; } - saverr = lo_change_cred(req, &old); + saverr = lo_change_cred(req, &old, lo->change_umask && !S_ISLNK(mode)); if (saverr) { goto out; } @@ -1147,7 +1164,7 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_t parent, saverr = errno; - lo_restore_cred(&old); + lo_restore_cred(&old, lo->change_umask && !S_ISLNK(mode)); if (res == -1) { goto out; @@ -1828,7 +1845,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name, return; } - err = lo_change_cred(req, &old); + err = lo_change_cred(req, &old, lo->change_umask); if (err) { goto out; } @@ -1839,7 +1856,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name, fd = openat(parent_inode->fd, name, fi->flags | O_CREAT | O_EXCL, mode); err = fd == -1 ? errno : 0; - lo_restore_cred(&old); + lo_restore_cred(&old, lo->change_umask); /* Ignore the error if file exists and O_EXCL was not given */ if (err && (err != EEXIST || (fi->flags & O_EXCL))) {