Re: [PATCH 4/7] zloop: add storage element emulation

[Hannes Reinecke <hare@suse.de>]

On 10/5/26 11:46 AM, Damien Le Moal wrote:
> Emulate the storage element depopulation feature of SMR disks in the
> zloop driver. This emulation is controlled using the new stor_elements
> option.
> 
> This option can take several values:
>   - ZLOOP_STOR_ELEMENTS_NONE (0): no emulation (default)
>   - ZLOOP_STOR_ELEMENTS_RDWR (1): emulate all access storage elements
>     (e.g.  read+write heads)
>   - ZLOOP_STOR_ELEMENTS_PAIRS (2): emulate fractional access storage
>     elements (e.g. pairs of read and write heads)
> 
> If enabled with the value 1 or 2, the number of storage elements, or of
> pairs of fractional access storage elements, is automatically calculated
> based on the number of zones of the device so that we have at least 2 and
> at most 32 storage elements (or 2 pairs of fractional access storage
> elements).
> 
> The mapping of zones to storage elements is defined simply as the modulo
> of a zone number and a storage element ID. E.g, removing a storage
> element from a set of 4 storage elements will offline 1 zone every 4
> zones.
> 
> The storage element management operations are specified with the
> zloop_se_ops (struct blk_storage_elements_ops).
> 
> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
> ---
>   .../admin-guide/blockdev/zoned_loop.rst       |   8 +-
>   drivers/block/zloop.c                         | 510 +++++++++++++++++-
>   2 files changed, 490 insertions(+), 28 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@kernel.org>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
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