Re: [PATCH] IB core: Fix locking on device numbers allocation

[Eli Cohen <eli-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>]

On Wed, Mar 24, 2010 at 10:39:18AM -0700, Roland Dreier wrote:
> 
> Looks like a good catch.  I assume you found this through inspection and
> not hitting it practice?
Correct, I caught this from inspecting the code.

>  Also it seems user_mad.c would need the same fix.
Yes, I missed that.

> 
> Although looking at this I wonder if we do need that lock... we don't
> seem to do any locking when we do the clear_bit in the dev_map, and all
> of this is done through the device add/remove callback, which seems to
> be serialized by the device_mutex in device.c.  But we probably don't
> want to make that a requirement in case we parallelize in the future.
> 
I missed the fact the clear_bit is not atomic. So to make this
complete I will send a new patch with protection on the clear bit.
Would you like me to send a patch for user_mad too or would you push
that?
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