Re: Linux 2.6.10-rc2 OOPS on boot with 3ware + reiserfs

[James Bottomley]

On Thu, 2004-11-18 at 13:10, Jens Axboe wrote:
> It is a double requeue. The SCSI path looks really messy (and buggy
> there). What happens is that the host queuecommand sets DID_ERROR and
> calls scsi_done() on the command, which may decide the commands need
> retrying and thus requeue it. Upon return from queuecommand, the SCSI
> layer initiates a requeue of the request because queuecommand returned
> 1. Double requeue, request list is now screwed.
> 
> James, it looks like the queuecommand returns need an overhaul so it's
> clear who does what and when.

Hmm, I thought the Documentation/scsi/scsi_mid_low_api.txt was quite
clear on this:

 *      Command ownership.  If the driver returns zero, it owns the
 *      command and must take responsibility for ensuring the 'done'
 *      callback is executed.  Note: the driver may call done before
 *      returning zero, but after it has called done, it may not
 *      return any value other than zero.  If the driver makes a
 *      non-zero return, it must not execute the command's done
 *      callback at any time.

The 3ware driver is clearly in violation by calling done and then
returning one.

James


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