[dm-devel] dm: dm-zoned: Ignore last smaller runt zone

[Mike Snitzer]

On Sat, Oct 28 2017 at  3:39am -0400,
Damien Le Moal <damien.lemoal at wdc.com> wrote:

> The scsi layer allows ZBC drives to have a smaller last runt zone. For
> such device, specifying the entire capacity for a dm-zoned target table
> entry fails as the specified capacity is not aligned on the device zone
> size indicated in the request queue structure of the device.
> 
> Fix this problem by ignoring the last runt zone in the entry length
> when seting up the dm-zoned target (ctr method) and when iterating table
> entries of the target (iterate_devices method). This allows dm-zoned
> users to still easily setup a target using the entire device capacity
> (as mandated by dm-zoned) or the aligned capacity excluding thelast runt
> zone.
> 
> While at it, replace direct references to the device queue chunk_sectors
> limit with calls to the accessor blk_queue_zone_sectors().
> 
> Reported-by: Peter Desnoyers <pjd at ccs.neu.edu>
> Signed-off-by: Damien Le Moal <damien.lemoal at wdc.com>

Applied for 3.15 (also cc'd stable@)