From patchwork Tue Jun 30 03:34:30 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 489490 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 F2E4014091A for ; Tue, 30 Jun 2015 13:40:17 +1000 (AEST) Received: from localhost ([::1]:44872 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9mPA-0000VM-3f for incoming@patchwork.ozlabs.org; Mon, 29 Jun 2015 23:40:16 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53179) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9mGp-0002BT-F5 for qemu-devel@nongnu.org; Mon, 29 Jun 2015 23:31:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z9mGo-00008W-8l for qemu-devel@nongnu.org; Mon, 29 Jun 2015 23:31:39 -0400 Received: from [59.151.112.132] (port=40419 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z9mGm-0008GF-0B; Mon, 29 Jun 2015 23:31:38 -0400 X-IronPort-AV: E=Sophos;i="5.13,665,1427731200"; d="scan'208";a="97890026" Received: from unknown (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 30 Jun 2015 11:34:58 +0800 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t5U3TIgk027973; Tue, 30 Jun 2015 11:29:18 +0800 Received: from G08FNSTD140052.g08.fujitsu.local (10.167.226.52) by G08CNEXCHPEKD02.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Tue, 30 Jun 2015 11:30:58 +0800 From: Wen Congyang To: qemu devel , Fam Zheng , Max Reitz , Paolo Bonzini Date: Tue, 30 Jun 2015 11:34:30 +0800 Message-ID: <1435635285-5804-3-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1435635285-5804-1-git-send-email-wency@cn.fujitsu.com> References: <1435635285-5804-1-git-send-email-wency@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.52] X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 59.151.112.132 Cc: Kevin Wolf , qemu block , Alberto Garcia , Lai Jiangshan , Jiang Yunhong , Dong Eddie , "Dr. David Alan Gilbert" , Gonglei , Stefan Hajnoczi , Yang Hongyang , zhanghailiang Subject: [Qemu-devel] [PATCH COLO-BLOCK v7 02/17] quorum: implement block driver interfaces add/delete a BDS's child 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 Signed-off-by: Wen Congyang Signed-off-by: zhanghailiang Signed-off-by: Gonglei Cc: Alberto Garcia --- block/quorum.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 70 insertions(+), 2 deletions(-) diff --git a/block/quorum.c b/block/quorum.c index a7df17c..4a15493 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -67,6 +67,9 @@ typedef struct QuorumVotes { typedef struct BDRVQuorumState { BlockDriverState **bs; /* children BlockDriverStates */ int num_children; /* children count */ + int max_children; /* The maximum children count, we need to reallocate + * bs if num_children will larger than maximum. + */ int threshold; /* if less than threshold children reads gave the * same result a quorum error occurs. */ @@ -879,9 +882,9 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, ret = -EINVAL; goto exit; } - if (s->num_children < 2) { + if (s->num_children < 1) { error_setg(&local_err, - "Number of provided children must be greater than 1"); + "Number of provided children must be 1 or more"); ret = -EINVAL; goto exit; } @@ -930,6 +933,7 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags, /* allocate the children BlockDriverState array */ s->bs = g_new0(BlockDriverState *, s->num_children); opened = g_new0(bool, s->num_children); + s->max_children = s->num_children; for (i = 0; i < s->num_children; i++) { char indexstr[32]; @@ -1000,6 +1004,67 @@ static void quorum_attach_aio_context(BlockDriverState *bs, } } +static void quorum_add_child(BlockDriverState *bs, QDict *options, Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + int ret; + Error *local_err = NULL; + + bdrv_drain(bs); + + if (s->num_children == s->max_children) { + if (s->max_children >= INT_MAX / 2) { + error_setg(errp, "Too many children"); + return; + } + + s->bs = g_renew(BlockDriverState *, s->bs, s->max_children * 2); + memset(&s->bs[s->max_children], 0, s->max_children * sizeof(void *)); + s->max_children *= 2; + } + + ret = bdrv_open_image(&s->bs[s->num_children], NULL, options, "child", bs, + &child_format, false, &local_err); + if (ret < 0) { + error_propagate(errp, local_err); + return; + } + s->num_children++; + + /* TODO: Update vote_threshold */ +} + +static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs, + Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + int i; + + for (i = 0; i < s->num_children; i++) { + if (s->bs[i] == child_bs) { + break; + } + } + + if (i == s->num_children) { + error_setg(errp, "Invalid child"); + return; + } + + if (s->num_children == 1) { + error_setg(errp, "Cannot remove the last child"); + return; + } + + bdrv_drain(bs); + /* We can safe remove this child now */ + memmove(&s->bs[i], &s->bs[i+1], (s->num_children - i - 1) * sizeof(void *)); + s->num_children--; + s->bs[s->num_children] = NULL; + + /* TODO: update vote_threshold */ +} + static void quorum_refresh_filename(BlockDriverState *bs) { BDRVQuorumState *s = bs->opaque; @@ -1054,6 +1119,9 @@ static BlockDriver bdrv_quorum = { .bdrv_detach_aio_context = quorum_detach_aio_context, .bdrv_attach_aio_context = quorum_attach_aio_context, + .bdrv_add_child = quorum_add_child, + .bdrv_del_child = quorum_del_child, + .is_filter = true, .bdrv_recurse_is_first_non_filter = quorum_recurse_is_first_non_filter, };