Unmap does not guarantee that erased blocks will return all zeroes.
using write_zeroes when unmapping metadata gives the
desired behavior for a blob.
Only metadata pages will be cleared with write_zeroes in this patch;
blob data clusters will still call unmap. This behavior may be made
configurable in a later patch (to allow the user to request zeroing of
clusters rather than just unmapping).
Change-Id: I1b210abac110867ce703bcfdeb634eb45aa9d5c9
Signed-off-by: Seth Howell <seth.howell@intel.com>
Reviewed-on: https://review.gerrithub.io/372004
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>