From patchwork Fri Sep 18 10:13:13 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen Congyang X-Patchwork-Id: 519225 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 56D80140273 for ; Fri, 18 Sep 2015 20:15:14 +1000 (AEST) Received: from localhost ([::1]:36711 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZcshE-0008Pi-GX for incoming@patchwork.ozlabs.org; Fri, 18 Sep 2015 06:15:12 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45936) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZcsgS-0007Eu-4M for qemu-devel@nongnu.org; Fri, 18 Sep 2015 06:14:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZcsgO-0006gV-AO for qemu-devel@nongnu.org; Fri, 18 Sep 2015 06:14:24 -0400 Received: from [59.151.112.132] (port=54934 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZcsgN-0006fW-7Y; Fri, 18 Sep 2015 06:14:20 -0400 X-IronPort-AV: E=Sophos;i="5.15,520,1432569600"; d="scan'208";a="100865618" Received: from bogon (HELO edo.cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 18 Sep 2015 18:16:46 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (localhost.localdomain [127.0.0.1]) by edo.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id t8IADclb018091; Fri, 18 Sep 2015 18:13:38 +0800 Received: from G08FNSTD140052.g08.fujitsu.local (10.167.226.52) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.181.6; Fri, 18 Sep 2015 18:13:54 +0800 From: Wen Congyang To: qemu devel , Eric Blake , Markus Armbruster , Alberto Garcia , Stefan Hajnoczi Date: Fri, 18 Sep 2015 18:13:13 +0800 Message-ID: <1442571195-27116-3-git-send-email-wency@cn.fujitsu.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1442571195-27116-1-git-send-email-wency@cn.fujitsu.com> References: <1442571195-27116-1-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 , Jiang Yunhong , Dong Eddie , "Dr. David Alan Gilbert" , Gonglei , Yang Hongyang , zhanghailiang Subject: [Qemu-devel] [PATCH v4 2/4] quorum: implement bdrv_add_child() and bdrv_del_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 --- block.c | 6 ++--- block/quorum.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++-- include/block/block.h | 3 +++ 3 files changed, 76 insertions(+), 5 deletions(-) diff --git a/block.c b/block.c index bb7657b..4dc0e29 100644 --- a/block.c +++ b/block.c @@ -1079,9 +1079,9 @@ static int bdrv_fill_options(QDict **options, const char **pfilename, return 0; } -static BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, - BlockDriverState *child_bs, - const BdrvChildRole *child_role) +BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, + BlockDriverState *child_bs, + const BdrvChildRole *child_role) { BdrvChild *child = g_new(BdrvChild, 1); *child = (BdrvChild) { diff --git a/block/quorum.c b/block/quorum.c index 8fe53b4..111a57b 100644 --- a/block/quorum.c +++ b/block/quorum.c @@ -66,6 +66,9 @@ 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 grows larger than maximum. + */ int threshold; /* if less than threshold children reads gave the * same result a quorum error occurs. */ @@ -874,9 +877,9 @@ 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; } @@ -925,6 +928,7 @@ 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]; @@ -995,6 +999,67 @@ static void quorum_attach_aio_context(BlockDriverState *bs, } } +static void quorum_add_child(BlockDriverState *bs, BlockDriverState *child_bs, + Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + + bdrv_drain(bs); + + if (s->num_children == s->max_children) { + if (s->max_children >= INT_MAX) { + error_setg(errp, "Too many children"); + return; + } + + s->bs = g_renew(BlockDriverState *, s->bs, s->max_children + 1); + s->bs[s->num_children] = NULL; + s->max_children++; + } + + bdrv_ref(child_bs); + bdrv_attach_child(bs, child_bs, &child_format); + s->bs[s->num_children++] = child_bs; +} + +static void quorum_del_child(BlockDriverState *bs, BlockDriverState *child_bs, + Error **errp) +{ + BDRVQuorumState *s = bs->opaque; + BdrvChild *child; + int i; + + for (i = 0; i < s->num_children; i++) { + if (s->bs[i] == child_bs) { + break; + } + } + + QLIST_FOREACH(child, &bs->children, next) { + if (child->bs == child_bs) { + break; + } + } + + /* we have checked it in bdrv_del_child() */ + assert(i < s->num_children && child); + + if (s->num_children <= s->threshold) { + error_setg(errp, + "The number of children cannot be lower than the vote threshold %d", + s->threshold); + return; + } + + bdrv_drain(bs); + /* We can safely 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; + bdrv_unref_child(bs, child); +} + static void quorum_refresh_filename(BlockDriverState *bs) { BDRVQuorumState *s = bs->opaque; @@ -1049,6 +1114,9 @@ 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, }; diff --git a/include/block/block.h b/include/block/block.h index 665c56f..bd97399 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -514,6 +514,9 @@ void bdrv_disable_copy_on_read(BlockDriverState *bs); void bdrv_ref(BlockDriverState *bs); void bdrv_unref(BlockDriverState *bs); void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child); +BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, + BlockDriverState *child_bs, + const BdrvChildRole *child_role); bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp); void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);