Hey Hannes,
On Tue, Oct 17, 2023 at 12:07:14PM +0200, Hannes Reinecke wrote:
> zfcp_scsi_eh_host_reset_handler() would call fc_block_rport() to
> wait for all rports to become unblocked after host reset.
> But after host reset it might happen that the port is gone, hence
> fc_block_rport() might fail due to a missing port.
> But that's a perfectly legal operation; on FC remote ports might
> come and go.
> So this patch removes the call to fc_block_rport() after host
> reset. But with that rports may still be in blocked state after
> host reset, so we need to return FAST_IO_FAIL from host reset
> to avoid SCSI EH to fail commands prematurely if the rports
> are still blocked.
>
> Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
> Cc: Steffen Maier <maier@xxxxxxxxxxxxx
> Cc: Benjamin Block <bblock@xxxxxxxxxxxxx>
> ---
> drivers/s390/scsi/zfcp_scsi.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
> index b2a8cd792266..b1df853e6f66 100644
> --- a/drivers/s390/scsi/zfcp_scsi.c
> +++ b/drivers/s390/scsi/zfcp_scsi.c
> @@ -375,7 +375,7 @@ static int zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *scpnt)
> {
> struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scpnt->device);
> struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
> - int ret = SUCCESS, fc_ret;
> + int ret = FAST_IO_FAIL;
One thing I noticed, `scsi_ioctl_reset()` doesn't handle FAST_IO_FAIL at all;
it just considers that a failure, and returns EIO to userspace. I wonder if
this is appropriate after what we've discussed. In our case FAST_IO_FAIL
doesn't mean the host reset failed.
I don't think we need to adapt this patch for that - couldn't really - but
maybe there should be an extra change for that. Not exactly sure what even
uses that IOCTL interface, and how it'd react to an EIO.
>
> if (!(adapter->connection_features & FSF_FEATURE_NPIV_MODE)) {
> zfcp_erp_port_forced_reopen_all(adapter, 0, "schrh_p");
> @@ -383,10 +383,6 @@ static int zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *scpnt)
> }
> zfcp_erp_adapter_reopen(adapter, 0, "schrh_1");
> zfcp_erp_wait(adapter);
> - fc_ret = fc_block_scsi_eh(scpnt);
> - if (fc_ret)
> - ret = fc_ret;
> -
> zfcp_dbf_scsi_eh("schrh_r", adapter, ~0, ret);
> return ret;
> }
I think this works for us. Thanks.
Reviewed-by: Benjamin Block <bblock@xxxxxxxxxxxxx>
--
Best Regards, Benjamin Block / Linux on IBM Z Kernel Development
IBM Deutschland Research & Development GmbH / https://www.ibm.com/privacy
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