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From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Arjan van de Ven <arjan@linux.intel.com>,
	SCSI development list <linux-scsi@vger.kernel.org>,
	Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: Bug in SCSI async probing
Date: Tue, 26 May 2009 10:34:23 -0500	[thread overview]
Message-ID: <1243352063.2815.34.camel@localhost.localdomain> (raw)
In-Reply-To: <Pine.LNX.4.44L0.0905261040230.5554-100000@iolanthe.rowland.org>

On Tue, 2009-05-26 at 11:22 -0400, Alan Stern wrote:
> James & Arjan:
> 
> Am I missing something here?  It looks like
> 
> 	fastboot: make scsi probes asynchronous
> 
> has introduced a bug in the sd probing code.  AFAICT, there is now
> nothing to prevent do_scan_async() from returning before
> sd_probe_async() has run.

True, but this isn't really a problem.

> Doesn't this mean that there's nothing to prevent sd_remove() from 
> being called and trying to unregister the disk _before_ 
> sd_probe_async() has managed to register it?

Yes, we've been discussing this ... most of the removal functions now
need async_synchronize calls to mitigate this type of race.

James



  reply	other threads:[~2009-05-26 15:34 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-26 15:22 Bug in SCSI async probing Alan Stern
2009-05-26 15:34 ` James Bottomley [this message]
2009-05-26 18:34   ` Alan Stern
2009-05-26 18:56     ` James Bottomley
2009-05-26 19:48       ` Alan Stern
2009-05-26 20:35         ` James Bottomley
2009-05-26 21:04           ` Alan Stern
2009-05-26 21:23             ` James Bottomley
2009-05-26 21:52               ` Alan Stern

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