Re: dm crypt: use unsigned long long instead of sector_t to store iv_offset

[Mike Snitzer <snitzer@redhat.com>]

On Thu, Nov 01 2018 at  4:53am -0400,
AliOS system security <alios_sys_security@linux.alibaba.com> wrote:

> The iv_offset in the mapping table of crypt target is a 64bit number
> when iv mode is plain64 or plain64be. It will be assigned to iv_offset of
> struct crypt_config, cc_sector of struct convert_context and iv_sector of
> struct dm_crypt_request. These structures members are defined as a sector_t.
> But sector_t is 32bit when CONFIG_LBDAF is not set in 32bit kernel. In this
> situation sector_t is not big enough to store the 64bit iv_offset.

I really don't think this is needed.

cc->iv_offset can only address a the address space used to access the
device.  Which is expressed in terms of sectors.  Therefore if
CONFIG_LBDAF is not set in 32bit kernel then there is no need to address
beyond that which 'sector_t' addresses.

Please show proof to the contrary if you still think this change is
needed.

Mike