[PATCH] ipr: fix PCI permanent error handler

[PATCH] ipr: fix PCI permanent error handler

[Kleber Sacilotto de Souza]

The ipr driver can hang if it encounters enough PCI errors
to trigger the permanent error handler. The driver will attempt
to initiate a "bringdown" of the adapter and fail all pending
ops back. However, this bringdown is unlike any other bringdown
of the adapter in the code as the driver. In this code path we
end up failing back ops with allow_cmds still set to 1. This results
in some commands, the HCAM commands in particular, getting immediately
re-issued to the adapter on the done call, which results in
an infinite loop in ipr_fail_all_ops. Fix this by setting allow_cmds
to zero in this path. 

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>
---

 drivers/scsi/ipr.c |    1 +
 1 file changed, 1 insertion(+)

diff -puN drivers/scsi/ipr.c~ipr_pci_perm_failure_hang
drivers/scsi/ipr.c
--- linux-2.6/drivers/scsi/ipr.c~ipr_pci_perm_failure_hang
2009-04-15 09:25:21.000000000 -0500
+++ linux-2.6-bjking1/drivers/scsi/ipr.c        2009-04-15
09:25:39.000000000 -0500
@@ -6998,6 +6998,7 @@ static void ipr_pci_perm_failure(struct 
                ioa_cfg->sdt_state = ABORT_DUMP;
        ioa_cfg->reset_retries = IPR_NUM_RESET_RELOAD_RETRIES;
        ioa_cfg->in_ioa_bringdown = 1;
+       ioa_cfg->allow_cmds = 0;
        ipr_initiate_ioa_reset(ioa_cfg, IPR_SHUTDOWN_NONE);
        spin_unlock_irqrestore(ioa_cfg->host->host_lock, flags);
 }
_
--

Re: [PATCH] ipr: fix PCI permanent error handler

[James Bottomley]

On Thu, 2009-04-16 at 18:41 -0300, Kleber Sacilotto de Souza wrote:
> The ipr driver can hang if it encounters enough PCI errors
> to trigger the permanent error handler. The driver will attempt
> to initiate a "bringdown" of the adapter and fail all pending
> ops back. However, this bringdown is unlike any other bringdown
> of the adapter in the code as the driver. In this code path we
> end up failing back ops with allow_cmds still set to 1. This results
> in some commands, the HCAM commands in particular, getting immediately
> re-issued to the adapter on the done call, which results in
> an infinite loop in ipr_fail_all_ops. Fix this by setting allow_cmds
> to zero in this path. 
> 
> Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
> Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>

This signoff chain isn't right ... signoffs are supposed to document the
hands through which this patch has patched.  I take it this should be
acked-by Brian King instead?

James

Re: [PATCH] ipr: fix PCI permanent error handler

[Brian King]

James Bottomley wrote:
> On Thu, 2009-04-16 at 18:41 -0300, Kleber Sacilotto de Souza wrote:
>> The ipr driver can hang if it encounters enough PCI errors
>> to trigger the permanent error handler. The driver will attempt
>> to initiate a "bringdown" of the adapter and fail all pending
>> ops back. However, this bringdown is unlike any other bringdown
>> of the adapter in the code as the driver. In this code path we
>> end up failing back ops with allow_cmds still set to 1. This results
>> in some commands, the HCAM commands in particular, getting immediately
>> re-issued to the adapter on the done call, which results in
>> an infinite loop in ipr_fail_all_ops. Fix this by setting allow_cmds
>> to zero in this path. 
>>
>> Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
>> Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>
> 
> This signoff chain isn't right ... signoffs are supposed to document the
> hands through which this patch has patched.  I take it this should be
> acked-by Brian King instead?

Correct.


-- 
Brian King
Linux on Power Virtualization
IBM Linux Technology Center