Re: [Qemu-devel] [PATCH 3/3] virtio-scsi: Remove op blocker for dataplane

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, May 18, 2016 at 04:24:10PM +0800, Fam Zheng wrote:
> The previous patch dropped all op blockers from virtio-blk data plane.
> The situation of virtio-scsi is exactly the same it can drop them too.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  hw/scsi/virtio-scsi.c           | 62 -----------------------------------------
>  include/hw/virtio/virtio-scsi.h | 11 --------
>  2 files changed, 73 deletions(-)
> 
> diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
> index 30415c6..d26f490 100644
> --- a/hw/scsi/virtio-scsi.c
> +++ b/hw/scsi/virtio-scsi.c
> @@ -773,22 +773,6 @@ static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
>      }
>  }
>  
> -static void virtio_scsi_blk_insert_notifier(Notifier *n, void *data)
> -{
> -    VirtIOSCSIBlkChangeNotifier *cn = DO_UPCAST(VirtIOSCSIBlkChangeNotifier,
> -                                                n, n);
> -    assert(cn->sd->conf.blk == data);
> -    blk_op_block_all(cn->sd->conf.blk, cn->s->blocker);
> -}
> -
> -static void virtio_scsi_blk_remove_notifier(Notifier *n, void *data)
> -{
> -    VirtIOSCSIBlkChangeNotifier *cn = DO_UPCAST(VirtIOSCSIBlkChangeNotifier,
> -                                                n, n);
> -    assert(cn->sd->conf.blk == data);
> -    blk_op_unblock_all(cn->sd->conf.blk, cn->s->blocker);
> -}
> -
>  static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
>                                  Error **errp)
>  {
> @@ -797,29 +781,13 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev,
>      SCSIDevice *sd = SCSI_DEVICE(dev);
>  
>      if (s->ctx && !s->dataplane_fenced) {
> -        VirtIOSCSIBlkChangeNotifier *insert_notifier, *remove_notifier;
> -
>          if (blk_op_is_blocked(sd->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
>              return;
>          }
> -        blk_op_block_all(sd->conf.blk, s->blocker);
>          aio_context_acquire(s->ctx);
>          blk_set_aio_context(sd->conf.blk, s->ctx);
>          aio_context_release(s->ctx);
>  
> -        insert_notifier = g_new0(VirtIOSCSIBlkChangeNotifier, 1);
> -        insert_notifier->n.notify = virtio_scsi_blk_insert_notifier;
> -        insert_notifier->s = s;
> -        insert_notifier->sd = sd;
> -        blk_add_insert_bs_notifier(sd->conf.blk, &insert_notifier->n);
> -        QTAILQ_INSERT_TAIL(&s->insert_notifiers, insert_notifier, next);
> -
> -        remove_notifier = g_new0(VirtIOSCSIBlkChangeNotifier, 1);
> -        remove_notifier->n.notify = virtio_scsi_blk_remove_notifier;
> -        remove_notifier->s = s;
> -        remove_notifier->sd = sd;
> -        blk_add_remove_bs_notifier(sd->conf.blk, &remove_notifier->n);
> -        QTAILQ_INSERT_TAIL(&s->remove_notifiers, remove_notifier, next);
>      }
>  
>      if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
> @@ -835,7 +803,6 @@ static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
>      VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev);
>      VirtIOSCSI *s = VIRTIO_SCSI(vdev);
>      SCSIDevice *sd = SCSI_DEVICE(dev);
> -    VirtIOSCSIBlkChangeNotifier *insert_notifier, *remove_notifier;
>  
>      if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) {
>          virtio_scsi_push_event(s, sd,
> @@ -843,28 +810,6 @@ static void virtio_scsi_hotunplug(HotplugHandler *hotplug_dev, DeviceState *dev,
>                                 VIRTIO_SCSI_EVT_RESET_REMOVED);
>      }
>  
> -    if (s->ctx) {
> -        blk_op_unblock_all(sd->conf.blk, s->blocker);
> -    }
> -
> -    QTAILQ_FOREACH(insert_notifier, &s->insert_notifiers, next) {
> -        if (insert_notifier->sd == sd) {
> -            notifier_remove(&insert_notifier->n);
> -            QTAILQ_REMOVE(&s->insert_notifiers, insert_notifier, next);
> -            g_free(insert_notifier);
> -            break;
> -        }
> -    }
> -
> -    QTAILQ_FOREACH(remove_notifier, &s->remove_notifiers, next) {
> -        if (remove_notifier->sd == sd) {
> -            notifier_remove(&remove_notifier->n);
> -            QTAILQ_REMOVE(&s->remove_notifiers, remove_notifier, next);
> -            g_free(remove_notifier);
> -            break;
> -        }
> -    }
> -
>      qdev_simple_device_unplug_cb(hotplug_dev, dev, errp);
>  }
>  
> @@ -950,11 +895,6 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
>  
>      register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
>                      virtio_scsi_save, virtio_scsi_load, s);
> -
> -    error_setg(&s->blocker, "block device is in use by data plane");
> -
> -    QTAILQ_INIT(&s->insert_notifiers);
> -    QTAILQ_INIT(&s->remove_notifiers);
>  }
>  
>  static void virtio_scsi_instance_init(Object *obj)
> @@ -980,8 +920,6 @@ static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
>  {
>      VirtIOSCSI *s = VIRTIO_SCSI(dev);
>  
> -    error_free(s->blocker);
> -
>      unregister_savevm(dev, "virtio-scsi", s);
>      virtio_scsi_common_unrealize(dev, errp);
>  }
> diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
> index ba2f5ce..b515669 100644
> --- a/include/hw/virtio/virtio-scsi.h
> +++ b/include/hw/virtio/virtio-scsi.h
> @@ -68,13 +68,6 @@ typedef struct VirtIOSCSICommon {
>      VirtQueue **cmd_vqs;
>  } VirtIOSCSICommon;
>  
> -typedef struct VirtIOSCSIBlkChangeNotifier {
> -    Notifier n;
> -    struct VirtIOSCSI *s;
> -    SCSIDevice *sd;
> -    QTAILQ_ENTRY(VirtIOSCSIBlkChangeNotifier) next;
> -} VirtIOSCSIBlkChangeNotifier;
> -
>  typedef struct VirtIOSCSI {
>      VirtIOSCSICommon parent_obj;
>  
> @@ -85,14 +78,10 @@ typedef struct VirtIOSCSI {
>      /* Fields for dataplane below */
>      AioContext *ctx; /* one iothread per virtio-scsi-pci for now */
>  
> -    QTAILQ_HEAD(, VirtIOSCSIBlkChangeNotifier) insert_notifiers;
> -    QTAILQ_HEAD(, VirtIOSCSIBlkChangeNotifier) remove_notifiers;
> -
>      bool dataplane_started;
>      bool dataplane_starting;
>      bool dataplane_stopping;
>      bool dataplane_fenced;
> -    Error *blocker;
>      uint32_t host_features;
>  } VirtIOSCSI;
>  
> -- 
> 2.8.2