Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2021-01-20' into staging

nbd patches for 2021-01-20

- minor resource leak fixes in qemu-nbd
- ensure proper aio context when nbd server uses iothreads
- iotest refactorings in preparation for rewriting ./check to be more
flexible, and preparing for more nbd server reconnect features

# gpg: Signature made Thu 21 Jan 2021 02:28:19 GMT
# gpg:                using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2021-01-20:
  iotests.py: qemu_io(): reuse qemu_tool_pipe_and_status()
  iotests.py: fix qemu_tool_pipe_and_status()
  iotests/264: fix style
  iotests: define group in each iotest
  iotests/294: add shebang line
  iotests: make tests executable
  iotests: fix some whitespaces in test output files
  iotests/303: use dot slash for qcow2.py running
  iotests/277: use dot slash for nbd-fault-injector.py running
  nbd/server: Quiesce coroutines on context switch
  block: Honor blk_set_aio_context() context requirements
  qemu-nbd: Fix a memleak in nbd_client_thread()
  qemu-nbd: Fix a memleak in qemu_nbd_client_list()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 14 insertions, 3 deletions

diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 37499c5564..e9050c8987 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -172,6 +172,7 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev)
     VirtIOBlockDataPlane *s = vblk->dataplane;
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vblk)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    AioContext *old_context;
     unsigned i;
     unsigned nvqs = s->conf->num_queues;
     Error *local_err = NULL;
@@ -214,7 +215,10 @@ int virtio_blk_data_plane_start(VirtIODevice *vdev)
     vblk->dataplane_started = true;
     trace_virtio_blk_data_plane_start(s);
 
+    old_context = blk_get_aio_context(s->conf->conf.blk);
+    aio_context_acquire(old_context);
     r = blk_set_aio_context(s->conf->conf.blk, s->ctx, &local_err);
+    aio_context_release(old_context);
     if (r < 0) {
         error_report_err(local_err);
         goto fail_guest_notifiers;
diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c
index 71c337c7b7..3675f8deaf 100644
--- a/hw/block/dataplane/xen-block.c
+++ b/hw/block/dataplane/xen-block.c
@@ -725,6 +725,7 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
 {
     ERRP_GUARD();
     XenDevice *xendev = dataplane->xendev;
+    AioContext *old_context;
     unsigned int ring_size;
     unsigned int i;
 
@@ -808,10 +809,14 @@ void xen_block_dataplane_start(XenBlockDataPlane *dataplane,
         goto stop;
     }
 
-    aio_context_acquire(dataplane->ctx);
+    old_context = blk_get_aio_context(dataplane->blk);
+    aio_context_acquire(old_context);
     /* If other users keep the BlockBackend in the iothread, that's ok */
     blk_set_aio_context(dataplane->blk, dataplane->ctx, NULL);
+    aio_context_release(old_context);
+
     /* Only reason for failure is a NULL channel */
+    aio_context_acquire(dataplane->ctx);
     xen_device_set_event_channel_context(xendev, dataplane->event_channel,
                                          dataplane->ctx, &error_abort);
     aio_context_release(dataplane->ctx);
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 9690bc63c8..99ff261cea 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -849,15 +849,17 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
     VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
     SCSIDevice *sd = SCSI_DEVICE(dev);
+    AioContext *old_context;
     int ret;
 
     if (s->ctx && !s->dataplane_fenced) {
         if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
             return;
         }
-        virtio_scsi_acquire(s);
+        old_context = blk_get_aio_context(sd->conf.blk);
+        aio_context_acquire(old_context);
         ret = blk_set_aio_context(sd->conf.blk, s->ctx, errp);
-        virtio_scsi_release(s);
+        aio_context_release(old_context);
         if (ret < 0) {
             return;
         }