The intents of these arrays was to keep track in the
bdev layer of all base<->virtual bdev relationships -
i.e. which member disk bdevs make up a RAID bdev,
which logical volume bdevs are associated with a
bdev that contains an lvolstore, etc.
Currently none of this is used however. And trying
to keep track in the bdev layer instead of asking
the bdev modules for the relationships has a number
of complications. Early one, we tried to do this
with TAILQs - but that doesn't work since this can't
be done with a single TAILQ_ENTRY in the bdev
structures. So we moved to arrays - that works a bit
better, but then the pointer arrays have to be
realloc'd which isn't ideal.
The biggest problem though with these arrays is that
they held bdev pointers - not bdev descriptor pointers.
It's not really valid to access bdevs without a
descriptor - the descriptors are what make sure active
references are accounted for when a bdev is hotplugged.
Of course the bdev layer knows when a bdev is getting
removed and could go and do the updates to these
arrays separately - but that just seems very convoluted.
So for now just remove these arrays completely. If
there is a future need for the bdev layer to
understand relationships between bdevs, we can add
module APIs so that the generic layer can ask
the modules about the relationships.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I99ef1068240bff1262f64f234260cf2fb44df51d
Reviewed-on: https://review.gerrithub.io/420932
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: GangCao <gang.cao@intel.com>
671b77e5cd