Re: [PATCH] nvmet: move percpu handling into nvmet_ns_{enable,disable}

[Hannes Reinecke <hare@suse.de>]

On 1/24/25 11:50, Sagi Grimberg wrote:
> 
> 
> 
> On 24/01/2025 10:25, hare@kernel.org wrote:
>> From: Hannes Reinecke <hare@kernel.org>
>>
>> The namespace percpu counter protects pending I/O, and we can
>> only safely diable the namespace once the counter drop to zero.
>> So we need to init the percpu counter in nvmet_ns_enable(), and
>> wait for it to drop to zero in nvmet_ns_disable() to avoid having
>> I/O pending after the namespace has been disabled.
>>
>> Fixes: 74d16965d7ac ("nvmet-loop: avoid using mutex in IO hotpath")
> 
> Can you please describe the bug and scenario which you are hitting this 
> bug?
> It is also unclear how the above patch is causing this.
> 
>  From quick look patch itself looks reasonable.

Should've said: this is the fix to the reported blktest failure
on nvme/058...

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich