From patchwork Thu Aug 30 18:47:43 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Cody X-Patchwork-Id: 180868 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id E57642C0262 for ; Fri, 31 Aug 2012 05:46:03 +1000 (EST) Received: from localhost ([::1]:43942 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T79n4-0006Nz-5r for incoming@patchwork.ozlabs.org; Thu, 30 Aug 2012 14:48:30 -0400 Received: from eggs.gnu.org ([208.118.235.92]:40381) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T79mh-0005sv-9o for qemu-devel@nongnu.org; Thu, 30 Aug 2012 14:48:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T79mf-0005NI-75 for qemu-devel@nongnu.org; Thu, 30 Aug 2012 14:48:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:18300) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T79me-0005N1-W4 for qemu-devel@nongnu.org; Thu, 30 Aug 2012 14:48:05 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q7UIm1F6014325 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 30 Aug 2012 14:48:01 -0400 Received: from localhost (ovpn-112-23.phx2.redhat.com [10.3.112.23]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q7UIlxn0008118 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Thu, 30 Aug 2012 14:48:01 -0400 From: Jeff Cody To: qemu-devel@nongnu.org Date: Thu, 30 Aug 2012 14:47:43 -0400 Message-Id: <119e6ad34ce86318a8e07cf84bb7de4b2a750cee.1346351079.git.jcody@redhat.com> In-Reply-To: References: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, pbonzini@redhat.com, stefanha@gmail.com, eblake@redhat.com, supriyak@linux.vnet.ibm.com Subject: [Qemu-devel] [RFC v2 PATCH 5/6] block: helper function, to find the base image of a chain 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 This is a simple helper function, that will return the base image of a given image chain. Signed-off-by: Jeff Cody --- block.c | 16 ++++++++++++++++ block.h | 1 + 2 files changed, 17 insertions(+) diff --git a/block.c b/block.c index 11e275c..5f58600 100644 --- a/block.c +++ b/block.c @@ -3137,6 +3137,22 @@ int bdrv_get_backing_file_depth(BlockDriverState *bs) return 1 + bdrv_get_backing_file_depth(bs->backing_hd); } +BlockDriverState *bdrv_find_base(BlockDriverState *bs) +{ + BlockDriverState *curr_bs = NULL; + + if (!bs) { + return NULL; + } + + curr_bs = bs; + + while (curr_bs->backing_hd) { + curr_bs = curr_bs->backing_hd; + } + return curr_bs; +} + #define NB_SUFFIXES 4 char *get_human_readable_size(char *buf, int buf_size, int64_t size) diff --git a/block.h b/block.h index ee76869..376cc50 100644 --- a/block.h +++ b/block.h @@ -201,6 +201,7 @@ int bdrv_commit_all(void); int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file, const char *backing_fmt); void bdrv_register(BlockDriver *bdrv); +BlockDriverState *bdrv_find_base(BlockDriverState *bs); int bdrv_delete_intermediate(BlockDriverState *active, BlockDriverState *top, BlockDriverState *base); BlockDriverState *bdrv_find_child(BlockDriverState *active,