From patchwork Thu Jan 22 20:09:59 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 431983 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 215EA140083 for ; Fri, 23 Jan 2015 07:15:47 +1100 (AEDT) Received: from localhost ([::1]:55871 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YEOAL-0006FA-9D for incoming@patchwork.ozlabs.org; Thu, 22 Jan 2015 15:15:45 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49118) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YEO59-000682-MP for qemu-devel@nongnu.org; Thu, 22 Jan 2015 15:10:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YEO52-0005uq-6l for qemu-devel@nongnu.org; Thu, 22 Jan 2015 15:10:23 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52922) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YEO51-0005uf-W4 for qemu-devel@nongnu.org; Thu, 22 Jan 2015 15:10:16 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t0MKAF2O019870 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Thu, 22 Jan 2015 15:10:15 -0500 Received: from localhost ([10.18.17.71]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t0MKAEN5032312 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NO); Thu, 22 Jan 2015 15:10:15 -0500 From: Max Reitz To: qemu-devel@nongnu.org Date: Thu, 22 Jan 2015 15:09:59 -0500 Message-Id: <1421957411-31759-3-git-send-email-mreitz@redhat.com> In-Reply-To: <1421957411-31759-1-git-send-email-mreitz@redhat.com> References: <1421957411-31759-1-git-send-email-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , Markus Armbruster , Stefan Hajnoczi , Max Reitz Subject: [Qemu-devel] [PATCH v2 02/14] block: Add blk_new_open() 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 blk_new_with_bs() creates a BlockBackend with an empty BlockDriverState attached to it. Empty BDSs are not nice, therefore add an alternative function which combines blk_new_with_bs() with bdrv_open(). Note: In contrast to bdrv_open() which takes a BlockDriver parameter, blk_new_open() does not take such a parameter. This is because bdrv_open() opens a BlockDriverState, therefore it is naturally to be able to set the BlockDriver for that BDS. The fact that bdrv_open() can open more than a single BDS is merely some form of a byproduct. blk_new_open() on the other hand is intended to be used to create a whole tree of BlockDriverStates. Therefore, setting a single BlockDriver does not make much sense. Instead, the drivers to be used for each of the nodes must be configured through the "options" QDict; including the driver of the root BDS. Signed-off-by: Max Reitz --- block/block-backend.c | 34 ++++++++++++++++++++++++++++++++++ include/sysemu/block-backend.h | 3 +++ 2 files changed, 37 insertions(+) diff --git a/block/block-backend.c b/block/block-backend.c index b359545..543edaa 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -91,6 +91,40 @@ BlockBackend *blk_new_with_bs(const char *name, Error **errp) return blk; } +/* + * Calls blk_new_with_bs() and then calls bdrv_open() on the BlockDriverState. + * + * Just as with bdrv_open(), after having called this function the reference to + * @options belongs to the block layer (even on failure). + * + * TODO: Remove @filename and @flags; it should be possible to specify a whole + * BDS tree just by specifying the @options QDict (or @reference, + * alternatively). At the time of adding this function, this is not possible, + * though, so callers of this function have to be able to specify @filename and + * @flags. + */ +BlockBackend *blk_new_open(const char *name, const char *filename, + const char *reference, QDict *options, int flags, + Error **errp) +{ + BlockBackend *blk; + int ret; + + blk = blk_new_with_bs(name, errp); + if (!blk) { + QDECREF(options); + return NULL; + } + + ret = bdrv_open(&blk->bs, filename, reference, options, flags, NULL, errp); + if (ret < 0) { + blk_unref(blk); + return NULL; + } + + return blk; +} + static void blk_delete(BlockBackend *blk) { assert(!blk->refcnt); diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h index 38afa79..f39bb5c 100644 --- a/include/sysemu/block-backend.h +++ b/include/sysemu/block-backend.h @@ -62,6 +62,9 @@ typedef struct BlockDevOps { BlockBackend *blk_new(const char *name, Error **errp); BlockBackend *blk_new_with_bs(const char *name, Error **errp); +BlockBackend *blk_new_open(const char *name, const char *filename, + const char *reference, QDict *options, int flags, + Error **errp); void blk_ref(BlockBackend *blk); void blk_unref(BlockBackend *blk); const char *blk_name(BlockBackend *blk);