[PATCH 0/6] block: fix integrity offset/length conversions

[Anuj gupta]

> The block layer's integrity code currently sets the seed (initial
> reference tag) in units of 512-byte sectors but increments it in units
> of integrity intervals. Not only do the T10 DIF formats require ref tags
> to be the lower bits of the logical block address, but mixing the two
> units means the ref tags used for a particular logical block vary based
> on its offset within a read/write request. This looks to be a
> longstanding bug affecting block devices that support integrity with
> block sizes > 512 bytes; I'm surprised it wasn't noticed before.
>
This likely went unnoticed because the remap path compensates for it:
blk_integrity_prepare() rewrites the host-side sector-based ref tag to
the correct device-visible interval/LBA value, and
blk_integrity_complete() rewrites it back on reads. So for block-auto
PI, and for the FS-PI path that goes through the same remap, the
device-facing ref tag still comes out correct even though the host-side
seed is semantically wrong.