scsi: zfcp: fix missing REC trigger trace on terminate_rport_io for ERP_FAILED

For problem determination we always want to see when we were invoked on the
terminate_rport_io callback whether we perform something or not.

Temporal event sequence of interest with a long fast_io_fail_tmo of 27 sec:

loose remote port

t   workqueue
[s] zfcp_q_<dev>       IRQ                 zfcperp<dev>

=== ================== =================== ============================

  0                    recv RSCN
                       q p.test_link_work
    block rport
     start fast_io_fail_tmo
    send ADISC ELS
  4                    recv ADISC fail
                       block zfcp_port
                                           port forced reopen
                                           send open port
 12                    recv open port fail
                                           q p.gid_pn_work
                                           zfcp_erp_wakeup
                                           (zfcp_erp_wait would return)
    GID_PN fail

Before this point, we got a SCSI trace with tag "sctrpi1" on fast_io_fail,
e.g. with the typical 5 sec setting.

    port.status |= ERP_FAILED

If fast_io_fail_tmo triggers after this point, we missed a SCSI trace.

    workqueue
    fc_dl_<host>
    ==================
 27 fc_timeout_fail_rport_io
    fc_terminate_rport_io
    zfcp_scsi_terminate_rport_io
    zfcp_erp_port_forced_reopen
    _zfcp_erp_port_forced_reopen
     if (port.status & ERP_FAILED)
      return;

Therefore, write a trace before above early return.

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : REC
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1                      ZFCP_DBF_REC_TRIG
Tag            : sctrpi1                SCSI terminate rport I/O
LUN            : 0xffffffffffffffff                     none (invalid)
WWPN           : 0x<wwpn>
D_ID           : 0x<n_port_id>
Adapter status : 0x...
Port status    : 0x...
LUN status     : 0x00000000                             none (invalid)
Ready count    : 0x...
Running count  : 0x...
ERP want       : 0x03                   ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
ERP need       : 0xe0                   ZFCP_ERP_ACTION_FAILED

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Cc: <stable@vger.kernel.org> #2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index 3489b1b..5c368cd 100644 (file)
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -42,9 +42,13 @@ enum zfcp_erp_steps {
  * @ZFCP_ERP_ACTION_REOPEN_PORT_FORCED: Forced port recovery.
  * @ZFCP_ERP_ACTION_REOPEN_ADAPTER: Adapter recovery.
  * @ZFCP_ERP_ACTION_NONE: Eyecatcher pseudo flag to bitwise or-combine with
- *                       either of the other enum values.
+ *                       either of the first four enum values.
  *                       Used to indicate that an ERP action could not be
  *                       set up despite a detected need for some recovery.
+ * @ZFCP_ERP_ACTION_FAILED: Eyecatcher pseudo flag to bitwise or-combine with
+ *                         either of the first four enum values.
+ *                         Used to indicate that ERP not needed because
+ *                         the object has ZFCP_STATUS_COMMON_ERP_FAILED.
  */
 enum zfcp_erp_act_type {
        ZFCP_ERP_ACTION_REOPEN_LUN         = 1,
@@ -52,6 +56,7 @@ enum zfcp_erp_act_type {
        ZFCP_ERP_ACTION_REOPEN_PORT_FORCED = 3,
        ZFCP_ERP_ACTION_REOPEN_ADAPTER     = 4,
        ZFCP_ERP_ACTION_NONE               = 0xc0,
+       ZFCP_ERP_ACTION_FAILED             = 0xe0,
 };
 
 enum zfcp_erp_act_state {
@@ -379,8 +384,12 @@ static void _zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear,
        zfcp_erp_port_block(port, clear);
        zfcp_scsi_schedule_rport_block(port);
 
-       if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED)
+       if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_ERP_FAILED) {
+               zfcp_dbf_rec_trig(id, port->adapter, port, NULL,
+                                 ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
+                                 ZFCP_ERP_ACTION_FAILED);
                return;
+       }
 
        zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
                                port->adapter, port, NULL, id, 0);