[PATCH v3 09/30] block: Pre-allocate zone write plugs

[Bart Van Assche]

On 3/27/24 5:43 PM, Damien Le Moal wrote:
> Allocating zone write plugs using kmalloc() does not guarantee that
> enough write plugs can be allocated to simultaneously write up to
> the maximum number of active zones or maximum number of open zones of
> a zoned block device.
> 
> Avoid any issue with memory allocation by pre-allocating zone write
> plugs up to the disk maximum number of open zones or maximum number of
> active zones, whichever is larger. For zoned devices that do not have
> open or active zone limits, the default 128 is used as the number of
> write plugs to pre-allocate.
> 
> Pre-allocated zone write plugs are managed using a free list. If a
> change to the device zone limits is detected, the disk free list is
> grown if needed when blk_revalidate_disk_zones() is executed.

Is there a way to retry bio submission if allocating a zone write plug
fails? Would that make it possible to drop this patch?

Thanks,

Bart.