[dm-devel] [PATCH V6 3/4] sd_zbc: Fix report zones buffer allocation

[Damien Le Moal]

Martin,

On 2019/07/12 9:28, Martin K. Petersen wrote:
> 
> Damien,
> 
>> During disk scan and revalidation done with sd_revalidate(), the zones
>> of a zoned disk are checked using the helper function
>> blk_revalidate_disk_zones() if a configuration change is detected
>> (change in the number of zones or zone size). The function
>> blk_revalidate_disk_zones() issues report_zones calls that are very
>> large, that is, to obtain zone information for all zones of the disk
>> with a single command. The size of the report zones command buffer
>> necessary for such large request generally is lower than the disk
>> max_hw_sectors and KMALLOC_MAX_SIZE (4MB) and succeeds on boot (no
>> memory fragmentation), but often fail at run time (e.g. hot-plug
>> event). This causes the disk revalidation to fail and the disk
>> capacity to be changed to 0.
> 
> Probably easiest to funnel this through block with the rest of the
> series.

Sounds good to me.

Jens,

Could you please consider this series for 5.3 ? We have been using it in tests
since 2-3 weeks ago (5.2-rc6) without any problems. All revalidation problems
disappeared and with no side effects detected.

Thank you.

> Acked-by: Martin K. Petersen <martin.petersen at oracle.com>

Thanks !

-- 
Damien Le Moal
Western Digital Research