Re: [PATCH v3] null_blk: add support for max open/active zone limit for zoned devices

[Jens Axboe <axboe@kernel.dk>]

On 8/28/20 4:54 AM, Niklas Cassel wrote:
> Add support for user space to set a max open zone and a max active zone
> limit via configfs. By default, the default values are 0 == no limit.
> 
> Call the block layer API functions used for exposing the configured
> limits to sysfs.
> 
> Add accounting in null_blk_zoned so that these new limits are respected.
> Performing an operation that would exceed these limits results in a
> standard I/O error.
> 
> A max open zone limit exists in the ZBC standard.
> While null_blk_zoned is used to test the Zoned Block Device model in
> Linux, when it comes to differences between ZBC and ZNS, null_blk_zoned
> mostly follows ZBC.
> 
> Therefore, implement the manage open zone resources function from ZBC,
> but additionally add support for max active zones.
> This enables user space not only to test against a device with an open
> zone limit, but also to test against a device with an active zone limit.

Applied, thanks.

-- 
Jens Axboe