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From: Hannes Reinecke <hare@suse.de>
To: crazyrushstar@yahoo.com.tw
Cc: linux-scsi@vger.kernel.org
Subject: Re: Fwd: Re: scsi_scan_host will hang up my system!
Date: Wed, 04 Oct 2006 09:04:02 +0200	[thread overview]
Message-ID: <45235CE2.5080604@suse.de> (raw)
In-Reply-To: <20060920105845.48447.qmail@web18301.mail.tpe.yahoo.com>

crazyrushstar@yahoo.com.tw wrote:
> I am still reading scsi_mid_low_api.txt file.
> 
> Report my newly discovery.
> Trace to kernel code,function call to
> "blk_execute_rq(req->q, NULL, req, 1);" at scsi_lib.c
> It's too deep to trace.
> 
> This function not response to my driver so that insmod
> stuck.
> 
It looks as if you trigger a recursion in the block layer.
We've stumbled across this, too; it can happen if a driver returns
SCSI_MLQUEUE_HOST_BUSY errorneously. This can cause a really deep or
even infinite stack depth (as is triggers blk_requeue_request over and
over again).
Check for such a condition and make sure that it is _temporary_.
Otherwise use proper SCSI error codes (ie DID_NO_CONNECT) which do not
have this problem.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke			hare@suse.de
SuSE Linux Products GmbH		S390 & zSeries
Maxfeldstraße 5				+49 911 74053 688
90409 Nürnberg				http://www.suse.de
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      reply	other threads:[~2006-10-04  7:04 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-09-20 10:58 Fwd: Re: scsi_scan_host will hang up my system! crazyrushstar
2006-10-04  7:04 ` Hannes Reinecke [this message]

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