On 10/19/23 19:44, Benjamin Block wrote:
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.
Hmm. Indeed, that is not quite correct. EIO indicates an IO error,
whereas FAST_IO_FAIL signal more something like 'operation in progress,
couldn't complete in time'. So I guess EAGAIN is more appropriate here.
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.
Yes, we should be fixing that one. After all, FAST_IO_FAIL is a
perfectly legit return value for the EH functions, and we should
be handling it properly.
Will be adding a patch for it.
Thanks for the heads-up.
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
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