src/patches/suse-2.6.27.25/patches.arch/s390-12-13-zfcp_deadlock_port_scan_ERP.patch

   1 From: Gerald Schaefer <geraldsc@de.ibm.com>
   2 Subject: zfcp: deadlock between scheduled task and ERP
   3 References: bnc#487755,LTC#52846
   4
   5 Symptom:     I/O stall.
   6 Problem:     Waiting for the ERP in a task running in global wq
   7              is a bad idea especially if the ERP needs to run another
   8              job in this wq before it can finish. ->deadlock.
   9 Solution:    Remove the necessity to wait for the ERP.
  10
  11 Acked-by: John Jolly <jjolly@suse.de>
  12
  13 ---
  14  drivers/s390/scsi/zfcp_erp.c |    2 +-
  15  drivers/s390/scsi/zfcp_fc.c  |    1 -
  16  2 files changed, 1 insertion(+), 2 deletions(-)
  17
  18 Index: linux-sles11/drivers/s390/scsi/zfcp_erp.c
  19 ===================================================================
  20 --- linux-sles11.orig/drivers/s390/scsi/zfcp_erp.c
  21 +++ linux-sles11/drivers/s390/scsi/zfcp_erp.c
  22 @@ -725,7 +725,6 @@ static int zfcp_erp_adapter_strategy_gen
  23                 goto failed_openfcp;
  24
  25         atomic_set_mask(ZFCP_STATUS_COMMON_OPEN, &act->adapter->status);
  26 -       schedule_work(&act->adapter->scan_work);
  27
  28         return ZFCP_ERP_SUCCEEDED;
  29
  30 @@ -1215,6 +1214,7 @@ static void zfcp_erp_action_cleanup(stru
  31                 break;
  32
  33         case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
  34 +               schedule_work(&adapter->scan_work);
  35                 zfcp_adapter_put(adapter);
  36                 break;
  37         }
  38 Index: linux-sles11/drivers/s390/scsi/zfcp_fc.c
  39 ===================================================================
  40 --- linux-sles11.orig/drivers/s390/scsi/zfcp_fc.c
  41 +++ linux-sles11/drivers/s390/scsi/zfcp_fc.c
  42 @@ -631,7 +631,6 @@ int zfcp_scan_ports(struct zfcp_adapter
  43         max_entries = chain ? ZFCP_GPN_FT_MAX_ENTRIES : ZFCP_GPN_FT_ENTRIES;
  44         max_bytes = chain ? ZFCP_GPN_FT_MAX_SIZE : ZFCP_CT_SIZE_ONE_PAGE;
  45
  46 -       zfcp_erp_wait(adapter); /* wait until adapter is finished with ERP */
  47         if (fc_host_port_type(adapter->scsi_host) != FC_PORTTYPE_NPORT)
  48                 return 0;
  49