[SCSI] zfcp: Hold queue lock when checking port/unit handle for FCP command

We need to hold the queue-lock when checking whether we still have a valid
unit/port handle for the FCP command, i.e whether we can issue this request for
this unit/port. If the error recovery is about to close this unit/port, then it
competes for the queue-lock. If the close request issued by the error recovery
wins, then it is guaranteed that this unit/port has been blocked for other
requests.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 908e8b2..17c251c 100644 (file)
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -3593,6 +3593,12 @@ zfcp_fsf_send_fcp_command_task(struct zfcp_adapter *adapter,
                goto failed_req_create;
        }
 
+       if (unlikely(!atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED,
+                       &unit->status))) {
+               retval = -EBUSY;
+               goto unit_blocked;
+       }
+
        zfcp_unit_get(unit);
        fsf_req->unit = unit;
 
@@ -3733,6 +3739,7 @@ zfcp_fsf_send_fcp_command_task(struct zfcp_adapter *adapter,
  send_failed:
  no_fit:
  failed_scsi_cmnd:
+ unit_blocked:
        zfcp_unit_put(unit);
        zfcp_fsf_req_free(fsf_req);
        fsf_req = NULL;

diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 3298fd3..b9daf5c 100644 (file)
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -258,8 +258,9 @@ zfcp_scsi_command_async(struct zfcp_adapter *adapter, struct zfcp_unit *unit,
                goto out;
        }
 
-       if (unlikely(
-            !atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &unit->status))) {
+       tmp = zfcp_fsf_send_fcp_command_task(adapter, unit, scpnt, use_timer,
+                                            ZFCP_REQ_AUTO_CLEANUP);
+       if (unlikely(tmp == -EBUSY)) {
                ZFCP_LOG_DEBUG("adapter %s not ready or unit 0x%016Lx "
                               "on port 0x%016Lx in recovery\n",
                               zfcp_get_busid_by_unit(unit),
@@ -268,9 +269,6 @@ zfcp_scsi_command_async(struct zfcp_adapter *adapter, struct zfcp_unit *unit,
                goto out;
        }
 
-       tmp = zfcp_fsf_send_fcp_command_task(adapter, unit, scpnt, use_timer,
-                                            ZFCP_REQ_AUTO_CLEANUP);
-
        if (unlikely(tmp < 0)) {
                ZFCP_LOG_DEBUG("error: initiation of Send FCP Cmnd failed\n");
                retval = SCSI_MLQUEUE_HOST_BUSY;