From 3ba36d5627afb6009c91c71ae8709d5dac2cc03d Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 10 Oct 2018 20:21:46 +0100 Subject: [PATCH 20/49] block: Move bdrv_drain_all_begin() out of coroutine context RH-Author: Kevin Wolf Message-id: <20181010202213.7372-8-kwolf@redhat.com> Patchwork-id: 82599 O-Subject: [RHEL-8 qemu-kvm PATCH 17/44] block: Move bdrv_drain_all_begin() out of coroutine context Bugzilla: 1637976 RH-Acked-by: Max Reitz RH-Acked-by: John Snow RH-Acked-by: Thomas Huth Before we can introduce a single polling loop for all nodes in bdrv_drain_all_begin(), we must make sure to run it outside of coroutine context like we already do for bdrv_do_drained_begin(). Signed-off-by: Kevin Wolf (cherry picked from commit c8ca33d06def97d909a8511377b82994ae4e5981) Signed-off-by: Kevin Wolf Signed-off-by: Danilo C. L. de Paula --- block/io.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/block/io.c b/block/io.c index 23fe069..b58c91b 100644 --- a/block/io.c +++ b/block/io.c @@ -263,11 +263,16 @@ static void bdrv_co_drain_bh_cb(void *opaque) Coroutine *co = data->co; BlockDriverState *bs = data->bs; - bdrv_dec_in_flight(bs); - if (data->begin) { - bdrv_do_drained_begin(bs, data->recursive, data->parent, data->poll); + if (bs) { + bdrv_dec_in_flight(bs); + if (data->begin) { + bdrv_do_drained_begin(bs, data->recursive, data->parent, data->poll); + } else { + bdrv_do_drained_end(bs, data->recursive, data->parent); + } } else { - bdrv_do_drained_end(bs, data->recursive, data->parent); + assert(data->begin); + bdrv_drain_all_begin(); } data->done = true; @@ -293,7 +298,9 @@ static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs, .parent = parent, .poll = poll, }; - bdrv_inc_in_flight(bs); + if (bs) { + bdrv_inc_in_flight(bs); + } aio_bh_schedule_oneshot(bdrv_get_aio_context(bs), bdrv_co_drain_bh_cb, &data); @@ -463,6 +470,11 @@ void bdrv_drain_all_begin(void) BlockDriverState *bs; BdrvNextIterator it; + if (qemu_in_coroutine()) { + bdrv_co_yield_to_drain(NULL, true, false, NULL, true); + return; + } + /* BDRV_POLL_WHILE() for a node can only be called from its own I/O thread * or the main loop AioContext. We potentially use BDRV_POLL_WHILE() on * nodes in several different AioContexts, so make sure we're in the main -- 1.8.3.1