Re: [PATCH] block: avoid potential deadlock on zone revalidation failure

[Damien Le Moal <dlemoal@kernel.org>]

On 6/25/26 8:52 PM, Christoph Hellwig wrote:
> On Thu, Jun 25, 2026 at 03:28:24PM +0900, Damien Le Moal wrote:
> 
> [very long lockdep trace]
> 
>> +	/*
>> +	 * We may already have a zone write plug workqueue as this function may
>> +	 * be called after disk_free_zone_resources(), which does not destroy
>> +	 * the workqueue (the zone write plugs workqueue is destroyed at
>> +	 * disk_release() time).
>> +	 */
>> +	if (!disk->zone_wplugs_wq) {
> 
> Can't we just allocate this at add_disk time instead of the magic NULL
> check here to mirror the freeing side?

Just tried and yes, that is fine to do. A bit more code reshuffling that I
wanted for a fix, but in the end, a lot cleaner and simpler.
Will send V2 after some more tests.

-- 
Damien Le Moal
Western Digital Research