Hi Mike,
On Fri, 19 Sep 2008 11:06:04 -0500, Mike Christie wrote:
> Kiyoshi Ueda wrote:
> > This patch change scsi mid layer to export its busy status.
> > Not set the busy flag, when scsi can't dispatch I/Os anymore and
> > needs to kill I/Os. Otherwise, request stacking drivers may hold
> > requests forever.
> >
> >
> > Signed-off-by: Kiyoshi Ueda <k-ueda@xxxxxxxxxxxxx>
> > Signed-off-by: Jun'ichi Nomura <j-nomura@xxxxxxxxxxxxx>
> > Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/scsi/scsi.c | 4 ++--
> > drivers/scsi/scsi_lib.c | 23 ++++++++++++++++++++++-
> > 2 files changed, 24 insertions(+), 3 deletions(-)
> >
> > Index: scsi-misc-2.6/drivers/scsi/scsi_lib.c
> > ===================================================================
> > --- scsi-misc-2.6.orig/drivers/scsi/scsi_lib.c
> > +++ scsi-misc-2.6/drivers/scsi/scsi_lib.c
> > @@ -459,17 +459,30 @@ static void scsi_init_cmd_errh(struct sc
> >
> > void scsi_device_unbusy(struct scsi_device *sdev)
> > {
> > + int host_congested;
> > struct Scsi_Host *shost = sdev->host;
> > unsigned long flags;
> >
> > spin_lock_irqsave(shost->host_lock, flags);
> > shost->host_busy--;
> > + if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) ||
> > + shost->host_blocked || shost->host_self_blocked ||
> > + scsi_host_in_recovery(shost))
> > + host_congested = 1;
> > + else
> > + host_congested = 0;
> > +
>
> You might want to check if the starget busy too (scsi-misc has this but
> Jens's tree and linus do not)? The code below that I snipped from
> scsi_request_fn will set the congested bits if scsi_target_queue_ready
> returns 0, so above here you would want to clear it if it not congested
> anymore.
Yes, thank you for noticing that.
Since I was looking at scsi-misc and your target patch is in
scsi-post-merge, I overlooked it.
I'll rebase my patches and repost again.
Thanks,
Kiyoshi Ueda
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