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From: Johannes Thumshirn <jthumshirn@suse.de>
To: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	James Bottomley <james.bottomley@hansenpartnership.com>,
	linux-scsi@vger.kernel.org, Johannes Thumshirn <jth@kernel.org>,
	Dmitry Vyukov <dvyukov@google.com>,
	stable@vger.kernel.org, Hannes Reinecke <hare@suse.com>
Subject: Re: [PATCH] sg: protect access to to 'reserved' page array
Date: Wed, 1 Feb 2017 14:18:52 +0100	[thread overview]
Message-ID: <20170201131852.GC3661@linux-x5ow.site> (raw)
In-Reply-To: <20170201131247.GA5384@lst.de>

On Wed, Feb 01, 2017 at 02:12:48PM +0100, Christoph Hellwig wrote:
> 
> This seems to be abusing an atomic bitflag as a lock.  And I think
> in general we have two different things here that this patch conflates:
> 
>  a) a lock to protect building and using the reserve lists
>  b) a flag is a reservations is in use

I did have a patch doing exactly that but (appart from lockdep complaints) we
decided to drop it, as it made the code even more confusing.

-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

  reply	other threads:[~2017-02-01 13:18 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-01 11:22 [PATCH] sg: protect access to to 'reserved' page array Hannes Reinecke
2017-02-01 11:23 ` Johannes Thumshirn
2017-02-01 11:46 ` kbuild test robot
2017-02-01 11:49 ` kbuild test robot
2017-02-01 13:12 ` Christoph Hellwig
2017-02-01 13:18   ` Johannes Thumshirn [this message]
2017-02-01 13:21   ` Hannes Reinecke
2017-02-14 20:48     ` Dmitry Vyukov
2017-02-15  6:54       ` Hannes Reinecke

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