Make examine work with asynchronous bdev startup.
We need to count references of bdevs that are being examined,
for the case when single cache bdev is referenced by multiple OCF
vbdevs.
The construct function is not in fact asynchronous yet,
but will be after adopting "trylock" API. Adopting trylock
requires a lot of changes, so this patch is really to split
implementation.
Change-Id: I6ac091f2dd48462e74aa89cf54acb0306c30673b
Signed-off-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/450033
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
ac2b06c809