When nbd_close() is called from a coroutine, the connection_co never
gets to run, and thus nbd_teardown_connection() hangs.
This is because aio_co_enter() only puts the connection_co into the main
coroutine's wake-up queue, so this main coroutine needs to yield and
wait for connection_co to terminate.
Suggested-by: Kevin Wolf <kw...@redhat.com>
Signed-off-by: Max Reitz <mre...@redhat.com>
Message-Id: <20200122164532.178040-2-mre...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Maxim Levitsky <mlevi...@redhat.com>
Signed-off-by: Max Reitz <mre...@redhat.com>
---
block/nbd.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/block/nbd.c b/block/nbd.c
index d085554f21..6d3b22f844 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -70,6 +70,7 @@ typedef struct BDRVNBDState {
CoMutex send_mutex;
CoQueue free_sema;
Coroutine *connection_co;
+ Coroutine *teardown_co;
QemuCoSleepState *connection_co_sleep_ns_state;
bool drained;
bool wait_drained_end;
@@ -203,7 +204,15 @@ static void nbd_teardown_connection(BlockDriverState *bs)
qemu_co_sleep_wake(s->connection_co_sleep_ns_state);
}
}
- BDRV_POLL_WHILE(bs, s->connection_co);
+ if (qemu_in_coroutine()) {
+ s->teardown_co = qemu_coroutine_self();
+ /* connection_co resumes us when it terminates */
+ qemu_coroutine_yield();
+ s->teardown_co = NULL;
+ } else {
+ BDRV_POLL_WHILE(bs, s->connection_co);
+ }
+ assert(!s->connection_co);
}
static bool nbd_client_connecting(BDRVNBDState *s)
@@ -395,6 +404,9 @@ static coroutine_fn void nbd_connection_entry(void *opaque)
s->ioc = NULL;
}
+ if (s->teardown_co) {
+ aio_co_wake(s->teardown_co);
+ }
aio_wait_kick();
}
--
2.24.1
