From patchwork Thu Jul 14 13:28:14 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 648380 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)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rqy3T6RQRz9s2k for ; Thu, 14 Jul 2016 23:58:45 +1000 (AEST) Received: from localhost ([::1]:54070 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNhA3-0000nk-Fs for incoming@patchwork.ozlabs.org; Thu, 14 Jul 2016 09:58:43 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51916) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNgh5-00013p-Ia for qemu-devel@nongnu.org; Thu, 14 Jul 2016 09:28:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bNgh4-0006Zq-FV for qemu-devel@nongnu.org; Thu, 14 Jul 2016 09:28:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60998) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNggy-0006XG-G5; Thu, 14 Jul 2016 09:28:40 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1C2DF4EB07; Thu, 14 Jul 2016 13:28:40 +0000 (UTC) Received: from noname.redhat.com (ovpn-116-84.ams2.redhat.com [10.36.116.84]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u6EDSJ0x004420; Thu, 14 Jul 2016 09:28:38 -0400 From: Kevin Wolf To: qemu-block@nongnu.org Date: Thu, 14 Jul 2016 15:28:14 +0200 Message-Id: <1468502894-18098-12-git-send-email-kwolf@redhat.com> In-Reply-To: <1468502894-18098-1-git-send-email-kwolf@redhat.com> References: <1468502894-18098-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Thu, 14 Jul 2016 13:28:40 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v4 11/11] nbd-server: Allow node name for nbd-server-add X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, berto@igalia.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" There is no reason why an NBD server couldn't be started for any node, even if it's not on the top level. This converts nbd-server-add to accept a node-name. Note that there is a semantic difference between using a BlockBackend name and the node name of its root: In the former case, the NBD server is closed on eject; in the latter case, the NBD server doesn't drop its reference and keeps the image file open this way. Signed-off-by: Kevin Wolf --- blockdev-nbd.c | 21 +++++++++------------ qapi/block.json | 4 ++-- 2 files changed, 11 insertions(+), 14 deletions(-) diff --git a/blockdev-nbd.c b/blockdev-nbd.c index c437d32..ca41cc6 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -145,7 +145,8 @@ void qmp_nbd_server_start(SocketAddress *addr, void qmp_nbd_server_add(const char *device, bool has_writable, bool writable, Error **errp) { - BlockBackend *blk; + BlockDriverState *bs = NULL; + BlockBackend *on_eject_blk; NBDExport *exp; if (!nbd_server) { @@ -158,26 +159,22 @@ void qmp_nbd_server_add(const char *device, bool has_writable, bool writable, return; } - blk = blk_by_name(device); - if (!blk) { - error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND, - "Device '%s' not found", device); - return; - } - if (!blk_is_inserted(blk)) { - error_setg(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); + on_eject_blk = blk_by_name(device); + + bs = bdrv_lookup_bs(device, device, errp); + if (!bs) { return; } if (!has_writable) { writable = false; } - if (blk_is_read_only(blk)) { + if (bdrv_is_read_only(bs)) { writable = false; } - exp = nbd_export_new(blk_bs(blk), 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY, - NULL, false, blk, errp); + exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY, + NULL, false, on_eject_blk, errp); if (!exp) { return; } diff --git a/qapi/block.json b/qapi/block.json index db05169..8b08bd2 100644 --- a/qapi/block.json +++ b/qapi/block.json @@ -161,9 +161,9 @@ ## # @nbd-server-add: # -# Export a device to QEMU's embedded NBD server. +# Export a block node to QEMU's embedded NBD server. # -# @device: Block device to be exported +# @device: The device name or node name of the node to be exported # # @writable: Whether clients should be able to write to the device via the # NBD connection (default false). #optional