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

[Niklas Cassel <nks@flawful.org>]

On Mon, Sep 07, 2020 at 08:18:26AM +0000, Niklas Cassel wrote:
> On Fri, Aug 28, 2020 at 12:54:00PM +0200, 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.
> > 
> > Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
> > Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
> > ---
> > Changes since v2:
> > -Picked up Damien's Reviewed-by tag.
> > -Fixed a typo in the commit message.
> > -Renamed null_manage_zone_resources() to null_has_zone_resources().
> > 
> >  drivers/block/null_blk.h       |   5 +
> >  drivers/block/null_blk_main.c  |  16 +-
> >  drivers/block/null_blk_zoned.c | 319 +++++++++++++++++++++++++++------
> >  3 files changed, 282 insertions(+), 58 deletions(-)
> 
> Hello Jens,
> 
> A gentle ping on this.
> 
> As far as I can tell, there are no outstanding review comments.


Hello Jens,

Pinging you from another address, in case my corporate email is getting
stuck in your spam filter.

Kind regards,
Niklas