The drained_begin callbacks are not polling, all they do is schedule
any operations that must complete before bdrv_drained_end(). As such,
they can be called before bdrv_co_yield_to_drain(). Thus, the only
remaining task left for bdrv_co_drain_bh_cb() is the BDRV_POLL_WHILE()
loop. This patch extracts it into two new functions bdrv_drain_wait()
and bdrv_drain_all_wait(), so that it is easily accessible from
bdrv_co_drain_bh_cb().
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
block/io.c | 77 +++++++++++++++++++++++++++---------------------------
1 file changed, 38 insertions(+), 39 deletions(-)
diff --git a/block/io.c b/block/io.c
index a75f42ee13cb..fc4bc38ee9d5 100644
--- a/block/io.c
+++ b/block/io.c
@@ -245,13 +245,8 @@ bool bdrv_drain_poll(BlockDriverState *bs, bool
ignore_bds_parents)
return false;
}
-static bool bdrv_drain_poll_top_level(BlockDriverState *bs)
-{
- return bdrv_drain_poll(bs, false);
-}
-
-static void bdrv_do_drained_begin(BlockDriverState *bs, bool poll);
-
+static void bdrv_drain_wait(BlockDriverState *bs);
+static void bdrv_drain_all_wait(void);
static void bdrv_co_drain_bh_cb(void *opaque)
{
BdrvCoDrainData *data = opaque;
@@ -262,18 +257,17 @@ static void bdrv_co_drain_bh_cb(void *opaque)
AioContext *ctx = bdrv_get_aio_context(bs);
aio_context_acquire(ctx);
bdrv_dec_in_flight(bs);
- bdrv_do_drained_begin(bs, data->poll);
+ bdrv_drain_wait(bs);
aio_context_release(ctx);
} else {
- bdrv_drain_all_begin();
+ bdrv_drain_all_wait();
}
data->done = true;
aio_co_wake(co);
}
-static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs,
- bool poll)
+static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs)
{
BdrvCoDrainData data;
Coroutine *self = qemu_coroutine_self();
@@ -288,7 +282,6 @@ static void coroutine_fn
bdrv_co_yield_to_drain(BlockDriverState *bs,
.co = self,
.bs = bs,
.done = false,
- .poll = poll,
};
if (bs) {
@@ -319,15 +312,10 @@ static void coroutine_fn
bdrv_co_yield_to_drain(BlockDriverState *bs,
}
}
-static void bdrv_do_drained_begin(BlockDriverState *bs, bool poll)
+void bdrv_do_drained_begin_quiesce(BlockDriverState *bs)
{
IO_OR_GS_CODE();
- if (qemu_in_coroutine()) {
- bdrv_co_yield_to_drain(bs, poll);
- return;
- }
-
/* Stop things in parent-to-child order */
if (qatomic_fetch_inc(&bs->quiesce_counter) == 0) {
aio_disable_external(bdrv_get_aio_context(bs));
@@ -336,6 +324,23 @@ static void bdrv_do_drained_begin(BlockDriverState *bs,
bool poll)
bs->drv->bdrv_drain_begin(bs);
}
}
+}
+
+void bdrv_drained_begin(BlockDriverState *bs)
+{
+ IO_OR_GS_CODE();
+ bdrv_do_drained_begin_quiesce(bs);
+ bdrv_drain_wait(bs);
+}
+
+static void bdrv_drain_wait(BlockDriverState *bs)
+{
+ IO_OR_GS_CODE();
+
+ if (qemu_in_coroutine()) {
+ bdrv_co_yield_to_drain(bs);
+ return;
+ }
/*
* Wait for drained requests to finish.
@@ -346,20 +351,7 @@ static void bdrv_do_drained_begin(BlockDriverState *bs,
bool poll)
* includes other nodes in the same AioContext and therefore all child
* nodes.
*/
- if (poll) {
- BDRV_POLL_WHILE(bs, bdrv_drain_poll_top_level(bs));
- }
-}
-
-void bdrv_do_drained_begin_quiesce(BlockDriverState *bs)
-{
- bdrv_do_drained_begin(bs, false);
-}
-
-void bdrv_drained_begin(BlockDriverState *bs)
-{
- IO_OR_GS_CODE();
- bdrv_do_drained_begin(bs, true);
+ BDRV_POLL_WHILE(bs, bdrv_drain_poll(bs, false));
}
/**
@@ -438,11 +430,6 @@ void bdrv_drain_all_begin(void)
BlockDriverState *bs = NULL;
GLOBAL_STATE_CODE();
- if (qemu_in_coroutine()) {
- bdrv_co_yield_to_drain(NULL, true);
- return;
- }
-
/*
* bdrv queue is managed by record/replay,
* waiting for finishing the I/O requests may
@@ -464,18 +451,30 @@ void bdrv_drain_all_begin(void)
AioContext *aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(aio_context);
- bdrv_do_drained_begin(bs, false);
+ bdrv_do_drained_begin_quiesce(bs);
aio_context_release(aio_context);
}
/* Now poll the in-flight requests */
- AIO_WAIT_WHILE(NULL, bdrv_drain_all_poll());
+ bdrv_drain_all_wait();
while ((bs = bdrv_next_all_states(bs))) {
bdrv_drain_assert_idle(bs);
}
}
+static void bdrv_drain_all_wait(void)
+{
+ GLOBAL_STATE_CODE();
+
+ if (qemu_in_coroutine()) {
+ bdrv_co_yield_to_drain(NULL);
+ return;
+ }
+
+ AIO_WAIT_WHILE(NULL, bdrv_drain_all_poll());
+}
+
void bdrv_drain_all_end_quiesce(BlockDriverState *bs)
{
GLOBAL_STATE_CODE();
--
2.38.1
