From patchwork Wed Jul 31 10:14:00 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 263679 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 43D612C0040 for ; Wed, 31 Jul 2013 21:34:01 +1000 (EST) Received: from localhost ([::1]:50443 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V4UfC-00063G-R4 for incoming@patchwork.ozlabs.org; Wed, 31 Jul 2013 07:33:54 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45202) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V4Uet-000634-Tz for qemu-devel@nongnu.org; Wed, 31 Jul 2013 07:33:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V4Uen-0004yh-TI for qemu-devel@nongnu.org; Wed, 31 Jul 2013 07:33:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:65271) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V4TQk-0003Ik-Hj for qemu-devel@nongnu.org; Wed, 31 Jul 2013 06:14:54 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r6VAEsRr007472 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 31 Jul 2013 06:14:54 -0400 Received: from T430s.nay.redhat.com ([10.66.6.13]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r6VAEURm001246; Wed, 31 Jul 2013 06:14:51 -0400 From: Fam Zheng To: qemu-devel@nongnu.org Date: Wed, 31 Jul 2013 18:14:00 +0800 Message-Id: <1375265640-27307-8-git-send-email-famz@redhat.com> In-Reply-To: <1375265640-27307-1-git-send-email-famz@redhat.com> References: <1375265640-27307-1-git-send-email-famz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, jcody@redhat.com, famz@redhat.com, stefanha@redhat.com Subject: [Qemu-devel] [PATCH v3 7/7] nbd: use BlockDriverState refcnt X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Previously, nbd calls drive_get_ref() on the drive of bs. A BDS doesn't always have associated dinfo, which nbd doesn't care either. We already have BDS ref count, so use it to make it safe for a BDS w/o blockdev. Signed-off-by: Fam Zheng Reviewed-by: Wenchao Xia --- blockdev-nbd.c | 10 +--------- nbd.c | 5 +++++ 2 files changed, 6 insertions(+), 9 deletions(-) diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 95f10c8..922cf56 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -69,12 +69,6 @@ static void nbd_close_notifier(Notifier *n, void *data) g_free(cn); } -static void nbd_server_put_ref(NBDExport *exp) -{ - BlockDriverState *bs = nbd_export_get_blockdev(exp); - drive_put_ref(drive_get_by_blockdev(bs)); -} - void qmp_nbd_server_add(const char *device, bool has_writable, bool writable, Error **errp) { @@ -105,11 +99,9 @@ void qmp_nbd_server_add(const char *device, bool has_writable, bool writable, writable = false; } - exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY, - nbd_server_put_ref); + exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY, NULL); nbd_export_set_name(exp, device); - drive_get_ref(drive_get_by_blockdev(bs)); n = g_malloc0(sizeof(NBDCloseNotifier)); n->n.notify = nbd_close_notifier; diff --git a/nbd.c b/nbd.c index 2606403..f258cdd 100644 --- a/nbd.c +++ b/nbd.c @@ -881,6 +881,7 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, exp->nbdflags = nbdflags; exp->size = size == -1 ? bdrv_getlength(bs) : size; exp->close = close; + bdrv_ref(bs); return exp; } @@ -927,6 +928,10 @@ void nbd_export_close(NBDExport *exp) } nbd_export_set_name(exp, NULL); nbd_export_put(exp); + if (exp->bs) { + bdrv_unref(exp->bs); + exp->bs = NULL; + } } void nbd_export_get(NBDExport *exp)