From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45259) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cUcHg-0002z8-Kl for qemu-devel@nongnu.org; Fri, 20 Jan 2017 11:43:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cUcHf-000374-MW for qemu-devel@nongnu.org; Fri, 20 Jan 2017 11:43:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56638) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cUcHf-00036v-GR for qemu-devel@nongnu.org; Fri, 20 Jan 2017 11:43:27 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (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 9680B80469 for ; Fri, 20 Jan 2017 16:43:27 +0000 (UTC) From: Paolo Bonzini Date: Fri, 20 Jan 2017 17:43:07 +0100 Message-Id: <20170120164322.21851-3-pbonzini@redhat.com> In-Reply-To: <20170120164322.21851-1-pbonzini@redhat.com> References: <20170120164322.21851-1-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 02/17] block-backend: allow blk_prw from coroutine context List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: stefanha@redhat.com, famz@redhat.com qcow2_create2 calls this. Do not run a nested event loop, as that breaks when aio_co_wake tries to queue the coroutine on the co_queue_wakeup list of the currently running one. Reviewed-by: Stefan Hajnoczi Signed-off-by: Paolo Bonzini --- block/block-backend.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/block/block-backend.c b/block/block-backend.c index efbf398..1177598 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -880,7 +880,6 @@ static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, { QEMUIOVector qiov; struct iovec iov; - Coroutine *co; BlkRwCo rwco; iov = (struct iovec) { @@ -897,9 +896,14 @@ static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, .ret = NOT_DONE, }; - co = qemu_coroutine_create(co_entry, &rwco); - qemu_coroutine_enter(co); - BDRV_POLL_WHILE(blk_bs(blk), rwco.ret == NOT_DONE); + if (qemu_in_coroutine()) { + /* Fast-path if already in coroutine context */ + co_entry(&rwco); + } else { + Coroutine *co = qemu_coroutine_create(co_entry, &rwco); + qemu_coroutine_enter(co); + BDRV_POLL_WHILE(blk_bs(blk), rwco.ret == NOT_DONE); + } return rwco.ret; } -- 2.9.3