From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60513) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eEYbD-0002T1-5H for qemu-devel@nongnu.org; Tue, 14 Nov 2017 05:37:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eEYbC-0004P6-AM for qemu-devel@nongnu.org; Tue, 14 Nov 2017 05:37:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52190) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eEYbC-0004Oc-47 for qemu-devel@nongnu.org; Tue, 14 Nov 2017 05:37:46 -0500 From: Stefan Hajnoczi Date: Tue, 14 Nov 2017 10:37:19 +0000 Message-Id: <20171114103721.13869-4-stefanha@redhat.com> In-Reply-To: <20171114103721.13869-1-stefanha@redhat.com> References: <20171114103721.13869-1-stefanha@redhat.com> Subject: [Qemu-devel] [PULL for-2.11-rc2 3/5] block: Check for inserted BlockDriverState in blk_io_limits_disable() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Alberto Garcia , Stefan Hajnoczi From: Alberto Garcia When you set I/O limits using block_set_io_throttle or the command line throttling.* options they are kept in the BlockBackend regardless of whether a BlockDriverState is attached to the backend or not. Therefore when removing the limits using blk_io_limits_disable() we need to check if there's a BDS before attempting to drain it, else it will crash QEMU. This can be reproduced very easily using HMP: (qemu) drive_add 0 if=none,throttling.iops-total=5000 (qemu) drive_del none0 Reported-by: sochin jiang Signed-off-by: Alberto Garcia Reviewed-by: Max Reitz Message-id: 0d3a67ce8d948bb33e08672564714dcfb76a3d8c.1510339534.git.berto@igalia.com Signed-off-by: Stefan Hajnoczi --- block/block-backend.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index ab75da32c9..df92a6280d 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1980,10 +1980,16 @@ void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg) void blk_io_limits_disable(BlockBackend *blk) { - assert(blk->public.throttle_group_member.throttle_state); - bdrv_drained_begin(blk_bs(blk)); - throttle_group_unregister_tgm(&blk->public.throttle_group_member); - bdrv_drained_end(blk_bs(blk)); + BlockDriverState *bs = blk_bs(blk); + ThrottleGroupMember *tgm = &blk->public.throttle_group_member; + assert(tgm->throttle_state); + if (bs) { + bdrv_drained_begin(bs); + } + throttle_group_unregister_tgm(tgm); + if (bs) { + bdrv_drained_end(bs); + } } /* should be called before blk_set_io_limits if a limit is set */ -- 2.13.6