There should be a section of code in device hot unplug, checking
DriverInfo's ref, fail or do nothing when ref != 1. But I haven't found
that code, so not sure whether this patch will change the behavior in
device hot unplug.
> block-migration.c does not actually use DriveInfo anywhere. Hence it's
> safe to drive ref code, we really only care about referencing BDS.
>
> Signed-off-by: Fam Zheng <f...@redhat.com>
> ---
> block-migration.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/block-migration.c b/block-migration.c
> index f803f20..daf9ec1 100644
> --- a/block-migration.c
> +++ b/block-migration.c
> @@ -336,8 +336,8 @@ static void init_blk_migration_it(void *opaque,
> BlockDriverState *bs)
> bmds->completed_sectors = 0;
> bmds->shared_base = block_mig_state.shared_base;
> alloc_aio_bitmap(bmds);
> - drive_get_ref(drive_get_by_blockdev(bs));
> bdrv_set_in_use(bs, 1);
> + bdrv_ref(bs);
>
> block_mig_state.total_sector_sum += sectors;
>
> @@ -575,7 +575,7 @@ static void blk_mig_cleanup(void)
> while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
> QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
> bdrv_set_in_use(bmds->bs, 0);
> - drive_put_ref(drive_get_by_blockdev(bmds->bs));
> + bdrv_unref(bmds->bs);
> g_free(bmds->aio_bitmap);
> g_free(bmds);
> }
>
--
Best Regards
Wenchao Xia
