From nobody Fri Oct 3 11:31:30 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1579810019; cv=none; d=zohomail.com; s=zohoarc; b=exgyVFbZF/swj5ZVbCR6zDShMmjrMFVoQ8x6qyPb1psz8LRL6NEXkj+CuRoKoy2e/YvgPbDQv7vkSu/dC4bcFM6aG0w2J8Ci+hdqv8K0/CVv+k4NUa5pd6dzWHfXcuiqAD6JM3sCNGPrLRi1n7x5CFI7QS+3KRyM9+DdeRV+OaQ= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1579810019; h=Content-Type:Content-Transfer-Encoding:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=H+lsqLvEJ0+MjVyMcNzat6sKkhsnsZbPamB7jAxb+Nw=; b=WwexHzieJjk3bwAqGAF/xF5xrbBQ5T9cC6jGfAsywNHKJ2Bus5VfzY8DF+Op32UGX2zxZlMt+rMLGbgmIX6GmgrduqFJbRJvvixjujF1TnEAkdhfMW3ef0KaIPykblEuKiEmiVNq3GKExIvC0BVmhKqdbNkwUUbmYYmnlbmJZBw= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1579810019770384.57767150580014; Thu, 23 Jan 2020 12:06:59 -0800 (PST) Received: from localhost ([::1]:32958 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iuikk-00029i-CU for importer@patchew.org; Thu, 23 Jan 2020 15:06:58 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42438) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iufen-00060Q-Ku for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:48:38 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iufem-0008I4-IG for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:48:37 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:26291 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iufem-0008HX-Fd for qemu-devel@nongnu.org; Thu, 23 Jan 2020 11:48:36 -0500 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-fmt1MvxHNxiWjr3tcuhqig-1; Thu, 23 Jan 2020 11:48:34 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F1F3B803A41 for ; Thu, 23 Jan 2020 16:48:33 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-116-110.ams2.redhat.com [10.36.116.110]) by smtp.corp.redhat.com (Postfix) with ESMTP id 48B9619C69; Thu, 23 Jan 2020 16:48:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579798116; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=H+lsqLvEJ0+MjVyMcNzat6sKkhsnsZbPamB7jAxb+Nw=; b=MRW+Rx6bOirBI0cV3J3FTBjns3uWSKv/04+TUf1oNVhnbddxQjQM3YuSKrfdjPbyah5chP aG0yOXn2YqCt3wrF+/hN4/C9tWjgUPUYvfXmKZ6Q4CM4+528jbxTgeoOXBor7P63KwJAg+ t0TbfCAuAsOofumlplX4HVFmEdCmtPc= From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com Subject: [PULL 088/108] virtiofsd: make lo_release() atomic Date: Thu, 23 Jan 2020 16:46:10 +0000 Message-Id: <20200123164630.91498-89-dgilbert@redhat.com> In-Reply-To: <20200123164630.91498-1-dgilbert@redhat.com> References: <20200123164630.91498-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: fmt1MvxHNxiWjr3tcuhqig-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 207.211.31.81 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: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: pass (identity @redhat.com) Content-Type: text/plain; charset="utf-8" From: Stefan Hajnoczi Hold the lock across both lo_map_get() and lo_map_remove() to prevent races between two FUSE_RELEASE requests. In this case I don't see a serious bug but it's safer to do things atomically. Signed-off-by: Stefan Hajnoczi Reviewed-by: Daniel P. Berrang=C3=A9 Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/passthrough_ll.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough= _ll.c index 9414935b52..690edbc4c5 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -1772,14 +1772,18 @@ static void lo_release(fuse_req_t req, fuse_ino_t i= no, struct fuse_file_info *fi) { struct lo_data *lo =3D lo_data(req); - int fd; + struct lo_map_elem *elem; + int fd =3D -1; =20 (void)ino; =20 - fd =3D lo_fi_fd(req, fi); - pthread_mutex_lock(&lo->mutex); - lo_map_remove(&lo->fd_map, fi->fh); + elem =3D lo_map_get(&lo->fd_map, fi->fh); + if (elem) { + fd =3D elem->fd; + elem =3D NULL; + lo_map_remove(&lo->fd_map, fi->fh); + } pthread_mutex_unlock(&lo->mutex); =20 close(fd); --=20 2.24.1