From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59822) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cfkLT-0006cl-VF for qemu-devel@nongnu.org; Mon, 20 Feb 2017 04:33:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cfkLT-000792-Ae for qemu-devel@nongnu.org; Mon, 20 Feb 2017 04:33:24 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43048) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cfkLT-00078e-5v for qemu-devel@nongnu.org; Mon, 20 Feb 2017 04:33:23 -0500 From: Stefan Hajnoczi Date: Mon, 20 Feb 2017 09:32:43 +0000 Message-Id: <20170220093304.20515-4-stefanha@redhat.com> In-Reply-To: <20170220093304.20515-1-stefanha@redhat.com> References: <20170220093304.20515-1-stefanha@redhat.com> Subject: [Qemu-devel] [PULL 03/24] 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: Peter Maydell , Paolo Bonzini , Stefan Hajnoczi From: Paolo Bonzini 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 Reviewed-by: Fam Zheng Message-id: 20170213135235.12274-4-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi --- 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