diff options
| author | Christof Schmitt <christof.schmitt@de.ibm.com> | 2009-07-13 15:06:10 +0200 |
|---|---|---|
| committer | James Bottomley <James.Bottomley@HansenPartnership.com> | 2009-07-30 08:49:57 -0500 |
| commit | cbf1ed0264da104573458aedc220ebfcd02567f6 (patch) | |
| tree | e3a8e5f815fd22c556a61189c0d3e0d0658fa87d | |
| parent | 85600f7f8370fe5b4be0debd8b401de7986b52ae (diff) | |
[SCSI] zfcp: Recover from stalled outbound queue
Depending on interruptions on some storage systems, the complete
channel can stall which looks like an outbound queue stall to Linux.
When trying to acquire a free SBAL for a non-SCSI command, zfcp waits
for 5 seconds for a free slot to appear. This is the right place to
detect a queue stall: If the wait times out, we assume a stalled queue
and try to recover this.
The overall strategy should be to trigger the erp from specific
events, and not try an overall escalation from one failed port to a
full-blown queue recovery. If we manage to send a command, the status
codes for this command or a timeout will trigger the right follow-on
actions.
Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
| -rw-r--r-- | drivers/s390/scsi/zfcp_fsf.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c index 0c24695a53c..b7e48844056 100644 --- a/drivers/s390/scsi/zfcp_fsf.c +++ b/drivers/s390/scsi/zfcp_fsf.c @@ -670,8 +670,11 @@ static int zfcp_fsf_req_sbal_get(struct zfcp_adapter *adapter) zfcp_fsf_sbal_check(adapter), 5 * HZ); if (ret > 0) return 0; - if (!ret) + if (!ret) { atomic_inc(&adapter->qdio_outb_full); + /* assume hanging outbound queue, try queue recovery */ + zfcp_erp_adapter_reopen(adapter, 0, "fsrsg_1", NULL); + } spin_lock_bh(&adapter->req_q_lock); return -EIO; |