From patchwork Wed May 25 17:39:38 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 626390 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 3rFKbX3myPz9sds for ; Thu, 26 May 2016 03:51:52 +1000 (AEST) Received: from localhost ([::1]:34353 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b5cyE-0007iH-By for incoming@patchwork.ozlabs.org; Wed, 25 May 2016 13:51:50 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49511) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b5cnW-0005uV-L0 for qemu-devel@nongnu.org; Wed, 25 May 2016 13:40:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b5cnQ-0004XD-IO for qemu-devel@nongnu.org; Wed, 25 May 2016 13:40:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51522) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b5cnJ-0004SH-Mw; Wed, 25 May 2016 13:40:33 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 42EE6C0B2EDF; Wed, 25 May 2016 17:40:33 +0000 (UTC) Received: from noname.redhat.com (ovpn-116-86.ams2.redhat.com [10.36.116.86]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u4PHeAtV024245; Wed, 25 May 2016 13:40:31 -0400 From: Kevin Wolf To: qemu-block@nongnu.org Date: Wed, 25 May 2016 19:39:38 +0200 Message-Id: <1464197996-4581-14-git-send-email-kwolf@redhat.com> In-Reply-To: <1464197996-4581-1-git-send-email-kwolf@redhat.com> References: <1464197996-4581-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 25 May 2016 17:40:33 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 13/31] block: Fix reconfiguring graph with drained nodes X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" When changing the BlockDriverState that a BdrvChild points to while the node is currently drained, we must call the .drained_end() parent callback. Conversely, when this means attaching a new node that is already drained, we need to call .drained_begin(). bdrv_root_attach_child() takes now an opaque parameter, which is needed because the callbacks must also be called if we're attaching a new child to the BlockBackend when the root node is already drained, and they need a way to identify the BlockBackend. Previously, child->opaque was set too late and the callbacks would still see it as NULL. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake Reviewed-by: Fam Zheng --- block.c | 18 ++++++++++++++---- block/block-backend.c | 9 +++++---- include/block/block_int.h | 3 ++- 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/block.c b/block.c index 351344e..598624f 100644 --- a/block.c +++ b/block.c @@ -1155,24 +1155,33 @@ static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs) BlockDriverState *old_bs = child->bs; if (old_bs) { + if (old_bs->quiesce_counter && child->role->drained_end) { + child->role->drained_end(child); + } QLIST_REMOVE(child, next_parent); } + + child->bs = new_bs; + if (new_bs) { QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent); + if (new_bs->quiesce_counter && child->role->drained_begin) { + child->role->drained_begin(child); + } } - - child->bs = new_bs; } BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, const char *child_name, - const BdrvChildRole *child_role) + const BdrvChildRole *child_role, + void *opaque) { BdrvChild *child = g_new(BdrvChild, 1); *child = (BdrvChild) { .bs = NULL, .name = g_strdup(child_name), .role = child_role, + .opaque = opaque, }; bdrv_replace_child(child, child_bs); @@ -1185,7 +1194,8 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, const char *child_name, const BdrvChildRole *child_role) { - BdrvChild *child = bdrv_root_attach_child(child_bs, child_name, child_role); + BdrvChild *child = bdrv_root_attach_child(child_bs, child_name, child_role, + NULL); QLIST_INSERT_HEAD(&parent_bs->children, child, next); return child; } diff --git a/block/block-backend.c b/block/block-backend.c index 4e8298b..14e528e 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -161,8 +161,7 @@ BlockBackend *blk_new_open(const char *filename, const char *reference, } blk_set_enable_write_cache(blk, true); - blk->root = bdrv_root_attach_child(bs, "root", &child_root); - blk->root->opaque = blk; + blk->root = bdrv_root_attach_child(bs, "root", &child_root, blk); return blk; } @@ -481,8 +480,7 @@ void blk_remove_bs(BlockBackend *blk) void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs) { bdrv_ref(bs); - blk->root = bdrv_root_attach_child(bs, "root", &child_root); - blk->root->opaque = blk; + blk->root = bdrv_root_attach_child(bs, "root", &child_root, blk); notifier_list_notify(&blk->insert_bs_notifiers, blk); if (blk->public.throttle_state) { @@ -1676,6 +1674,9 @@ static void blk_root_drained_begin(BdrvChild *child) { BlockBackend *blk = child->opaque; + /* Note that blk->root may not be accessible here yet if we are just + * attaching to a BlockDriverState that is drained. Use child instead. */ + if (blk->public.io_limits_disabled++ == 0) { throttle_group_restart_blk(blk); } diff --git a/include/block/block_int.h b/include/block/block_int.h index b6f4755..30a9717 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -719,7 +719,8 @@ void hmp_drive_add_node(Monitor *mon, const char *optstr); BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, const char *child_name, - const BdrvChildRole *child_role); + const BdrvChildRole *child_role, + void *opaque); void bdrv_root_unref_child(BdrvChild *child); const char *bdrv_get_parent_name(const BlockDriverState *bs);