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From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Boaz Harrosh <bharrosh@panasas.com>,
	SCSI development list <linux-scsi@vger.kernel.org>
Subject: Re: [PATCH] SCSI: handle HARDWARE_ERROR sense correctly
Date: Thu, 04 Dec 2008 15:02:53 -0600	[thread overview]
Message-ID: <1228424573.3363.54.camel@localhost.localdomain> (raw)
In-Reply-To: <Pine.LNX.4.44L0.0812041546260.2180-100000@iolanthe.rowland.org>

On Thu, 2008-12-04 at 15:49 -0500, Alan Stern wrote:
> This patch (as1183) fixes a bug in scsi_check_sense().  The routine is
> documented as returning one of SUCCESS, FAILED, or NEEDS_RETRY.  But
> in the HARDWARE_ERROR case it can return ADD_TO_MLQUEUE.  And since it
> does this without bothering to increment the retry count, it can lead
> to an infinite retry loop.
> 
> The fix is to return NEEDS_RETRY instead.  Then the caller,
> scsi_decide_disposition(), will do the right thing.

OK, but why?

The current behaviour is to retry the error until the command timeout
expires, which, I think is what was needed by the annoying arrays that
have retryable hardware errors.

What bug would this patch fix?  Because I can see it causing problems
with the arrays that originally reported this problem.

James



  reply	other threads:[~2008-12-04 21:02 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-04 20:49 [PATCH] SCSI: handle HARDWARE_ERROR sense correctly Alan Stern
2008-12-04 21:02 ` James Bottomley [this message]
2008-12-04 21:45   ` Alan Stern
2008-12-04 23:39     ` Mike Anderson
2008-12-08 15:10       ` Alan Stern
2008-12-16 15:27       ` Alan Stern
2008-12-16 19:14         ` James Bottomley
2008-12-16 19:56           ` Alan Stern
2008-12-16 21:49             ` James Bottomley
2008-12-17 15:09               ` Alan Stern
2008-12-05 14:41   ` Kai Makisara
2008-12-05 15:45     ` James Bottomley

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