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From: Hannes Reinecke <hare@suse.de>
To: Daniel Wagner <dwagner@suse.de>, linux-nvme@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, Keith Busch <kbusch@kernel.org>
Subject: Re: [PATCH v1] nvme: avoid race in shutdown namespace removal
Date: Mon, 30 Aug 2021 19:14:02 +0200	[thread overview]
Message-ID: <742108c3-7c76-0bc3-fc13-06acf975c25c@suse.de> (raw)
In-Reply-To: <20210830100443.b2zkdp4l3vi2gz42@carbon.lan>

On 8/30/21 12:04 PM, Daniel Wagner wrote:
> On Mon, Aug 30, 2021 at 11:36:18AM +0200, Daniel Wagner wrote:
>> Though one thing I am not really sure how it interacts with
>> nvme_init_ns_head() as we could be in running nvme_init_ns_head()
>> after we have set last_path = true. I haven't really figured
>> out yet what this would mean. Is this a real problem?
> 
> I suspect it will regress the very thing 5396fdac56d8 ("nvme: fix
> refcounting imbalance when all paths are down") tried to fix.
> 
Most likely. Do drop me a mail on how to create a reproducer for that; 
it's not exactly trivial as you need to patch qemu for that
(and, of course, those patches will not go upstream as they again hit a 
section which the maintainer deemed to be reworked any time now. So of 
course he can't possibly apply them.)
(I seem to have a particular spell of bad luck, seeing that it's the 
_third_ time this happened to me :-( )

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer

WARNING: multiple messages have this Message-ID (diff)
From: Hannes Reinecke <hare@suse.de>
To: Daniel Wagner <dwagner@suse.de>, linux-nvme@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, Keith Busch <kbusch@kernel.org>
Subject: Re: [PATCH v1] nvme: avoid race in shutdown namespace removal
Date: Mon, 30 Aug 2021 19:14:02 +0200	[thread overview]
Message-ID: <742108c3-7c76-0bc3-fc13-06acf975c25c@suse.de> (raw)
In-Reply-To: <20210830100443.b2zkdp4l3vi2gz42@carbon.lan>

On 8/30/21 12:04 PM, Daniel Wagner wrote:
> On Mon, Aug 30, 2021 at 11:36:18AM +0200, Daniel Wagner wrote:
>> Though one thing I am not really sure how it interacts with
>> nvme_init_ns_head() as we could be in running nvme_init_ns_head()
>> after we have set last_path = true. I haven't really figured
>> out yet what this would mean. Is this a real problem?
> 
> I suspect it will regress the very thing 5396fdac56d8 ("nvme: fix
> refcounting imbalance when all paths are down") tried to fix.
> 
Most likely. Do drop me a mail on how to create a reproducer for that; 
it's not exactly trivial as you need to patch qemu for that
(and, of course, those patches will not go upstream as they again hit a 
section which the maintainer deemed to be reworked any time now. So of 
course he can't possibly apply them.)
(I seem to have a particular spell of bad luck, seeing that it's the 
_third_ time this happened to me :-( )

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer

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  reply	other threads:[~2021-08-30 17:14 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-30  9:36 [PATCH v1] nvme: avoid race in shutdown namespace removal Daniel Wagner
2021-08-30  9:36 ` Daniel Wagner
2021-08-30 10:04 ` Daniel Wagner
2021-08-30 10:04   ` Daniel Wagner
2021-08-30 17:14   ` Hannes Reinecke [this message]
2021-08-30 17:14     ` Hannes Reinecke
2021-09-01 13:30     ` Christoph Hellwig
2021-09-01 13:30       ` Christoph Hellwig
2021-09-01 14:41       ` Sagi Grimberg
2021-09-01 14:41         ` Sagi Grimberg

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