diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2016-10-27 12:49:05 +0200 |
|---|---|---|
| committer | Fam Zheng <famz@redhat.com> | 2016-10-28 21:50:18 +0800 |
| commit | c9d1a56174339b0afdef63b7d151b38f4bb6dae5 (patch) | |
| tree | 1eb8359be422f1abbf98c5781cee063163861f67 /hw/scsi/virtio-scsi-dataplane.c | |
| parent | 9e944cb4744b527dd93aa989023739375a8880fb (diff) | |
| download | qemu-c9d1a56174339b0afdef63b7d151b38f4bb6dae5.zip | |
block: only call aio_poll on the current thread's AioContext
aio_poll is not thread safe; for example bdrv_drain can hang if
the last in-flight I/O operation is completed in the I/O thread after
the main thread has checked bs->in_flight.
The bug remains latent as long as all of it is called within
aio_context_acquire/aio_context_release, but this will change soon.
To fix this, if bdrv_drain is called from outside the I/O thread,
signal the main AioContext through a dummy bottom half. The event
loop then only runs in the I/O thread.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-18-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Diffstat (limited to 'hw/scsi/virtio-scsi-dataplane.c')
| -rw-r--r-- | hw/scsi/virtio-scsi-dataplane.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c index b173b94949..9424f0e057 100644 --- a/hw/scsi/virtio-scsi-dataplane.c +++ b/hw/scsi/virtio-scsi-dataplane.c @@ -189,13 +189,11 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s) assert(s->ctx == iothread_get_aio_context(vs->conf.iothread)); aio_context_acquire(s->ctx); - virtio_scsi_clear_aio(s); + aio_context_release(s->ctx); blk_drain_all(); /* ensure there are no in-flight requests */ - aio_context_release(s->ctx); - for (i = 0; i < vs->conf.num_queues + 2; i++) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); } |