From 35f106e68464d4ed9f2059a93f5c2ecd0750c05b Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 13 Feb 2017 14:52:20 +0100 Subject: block-backend: allow blk_prw from coroutine context 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 efbf398bb5..1177598020 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; } -- cgit v1.2.3