[dm-devel] [PATCH v5 2/8] drivers/pmem: Allow pmem_clear_poison() to accept arbitrary offset and len

[Christoph Hellwig]

On Tue, Feb 18, 2020 at 04:48:35PM -0500, Vivek Goyal wrote:
> Currently pmem_clear_poison() expects offset and len to be sector aligned.
> Atleast that seems to be the assumption with which code has been written.
> It is called only from pmem_do_bvec() which is called only from pmem_rw_page()
> and pmem_make_request() which will only passe sector aligned offset and len.
> 
> Soon we want use this function from dax_zero_page_range() code path which
> can try to zero arbitrary range of memory with-in a page. So update this
> function to assume that offset and length can be arbitrary and do the
> necessary alignments as needed.
> 
> nvdimm_clear_poison() seems to assume offset and len to be aligned to
> clear_err_unit boundary. But this is currently internal detail and is
> not exported for others to use. So for now, continue to align offset and
> length to SECTOR_SIZE boundary. Improving it further and to align it
> to clear_err_unit boundary is a TODO item for future.
> 
> Signed-off-by: Vivek Goyal <vgoyal at redhat.com>

This looks sensibel to me, but I'd really like to have Dan take at look.