From patchwork Fri May 23 13:29:45 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 351857 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 8E5E9140082 for ; Fri, 23 May 2014 23:34:31 +1000 (EST) Received: from localhost ([::1]:43133 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnpcD-0004PA-7C for incoming@patchwork.ozlabs.org; Fri, 23 May 2014 09:34:29 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45106) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnpXx-0006d5-J0 for qemu-devel@nongnu.org; Fri, 23 May 2014 09:30:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WnpXp-00031l-Pc for qemu-devel@nongnu.org; Fri, 23 May 2014 09:30:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47164) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnpXp-00031b-GA for qemu-devel@nongnu.org; Fri, 23 May 2014 09:29:57 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s4NDTt2t015889 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 23 May 2014 09:29:55 -0400 Received: from T430.nay.redhat.com (dhcp-14-247.nay.redhat.com [10.66.14.247]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s4NDTa0m001119; Fri, 23 May 2014 09:29:53 -0400 From: Fam Zheng To: qemu-devel@nongnu.org Date: Fri, 23 May 2014 21:29:45 +0800 Message-Id: <1400851788-32588-6-git-send-email-famz@redhat.com> In-Reply-To: <1400851788-32588-1-git-send-email-famz@redhat.com> References: <1400851788-32588-1-git-send-email-famz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , Benoit Canet , jcody@redhat.com, Max Reitz , Stefan Hajnoczi , Paolo Bonzini Subject: [Qemu-devel] [PATCH v2 5/8] block: Add bdrv_set_backing_hd() 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 the common but non-trivial steps to assign or change the backing_hd of BDS. Signed-off-by: Fam Zheng Reviewed-by: Stefan Hajnoczi Reviewed-by: Jeff Cody --- block.c | 36 +++++++++++++++++++++++------------- include/block/block.h | 1 + 2 files changed, 24 insertions(+), 13 deletions(-) diff --git a/block.c b/block.c index 64c48a5..911ba68 100644 --- a/block.c +++ b/block.c @@ -1094,6 +1094,21 @@ fail: return ret; } +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) +{ + + bs->backing_hd = backing_hd; + if (!backing_hd) { + goto out; + } + bs->open_flags &= ~BDRV_O_NO_BACKING; + pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); + pstrcpy(bs->backing_format, sizeof(bs->backing_format), + backing_hd->drv ? backing_hd->drv->format_name : ""); +out: + bdrv_refresh_limits(bs); +} + /* * Opens the backing file for a BlockDriverState if not yet open * @@ -1107,6 +1122,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) char *backing_filename = g_malloc0(PATH_MAX); int ret = 0; BlockDriver *back_drv = NULL; + BlockDriverState *backing_hd; Error *local_err = NULL; if (bs->backing_hd != NULL) { @@ -1129,27 +1145,26 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX); } + backing_hd = bdrv_new("", errp); + if (bs->backing_format[0] != '\0') { back_drv = bdrv_find_format(bs->backing_format); } assert(bs->backing_hd == NULL); - ret = bdrv_open(&bs->backing_hd, + ret = bdrv_open(&backing_hd, *backing_filename ? backing_filename : NULL, NULL, options, bdrv_backing_flags(bs->open_flags), back_drv, &local_err); if (ret < 0) { - bs->backing_hd = NULL; + bdrv_unref(backing_hd); + backing_hd = NULL; bs->open_flags |= BDRV_O_NO_BACKING; error_setg(errp, "Could not open backing file: %s", error_get_pretty(local_err)); error_free(local_err); goto free_exit; } - - if (bs->backing_hd->file) { - pstrcpy(bs->backing_file, sizeof(bs->backing_file), - bs->backing_hd->file->filename); - } + bdrv_set_backing_hd(bs, backing_hd); /* Recalculate the BlockLimits with the backing file */ bdrv_refresh_limits(bs); @@ -2043,12 +2058,7 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) /* The contents of 'tmp' will become bs_top, as we are * swapping bs_new and bs_top contents. */ - bs_top->backing_hd = bs_new; - bs_top->open_flags &= ~BDRV_O_NO_BACKING; - pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file), - bs_new->filename); - pstrcpy(bs_top->backing_format, sizeof(bs_top->backing_format), - bs_new->drv ? bs_new->drv->format_name : ""); + bdrv_set_backing_hd(bs_top, bs_new); } static void bdrv_delete(BlockDriverState *bs) diff --git a/include/block/block.h b/include/block/block.h index 22935f1..faee3aa 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -216,6 +216,7 @@ int bdrv_parse_discard_flags(const char *mode, int *flags); int bdrv_open_image(BlockDriverState **pbs, const char *filename, QDict *options, const char *bdref_key, int flags, bool allow_none, Error **errp); +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd); int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp); void bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp); int bdrv_open(BlockDriverState **pbs, const char *filename,