src/patches/suse-2.6.27.31/patches.arch/s390-15-03-zfcp-recover-stall.patch

   1 From: Gerald Schaefer <geraldsc@de.ibm.com>
   2 Subject: zfcp: Recover from stalled outbound queue
   3 References: bnc#518291,LTC#54460
   4
   5 Symptom:     In some error scenarious, the channel can stall. To
   6              Linux this looks like a stall in the outbound queue.
   7              Linux has to recover this.
   8 Problem:     There is no trigger to recover the queues if the outbound
   9              queue stalls.
  10 Solution:    When trying to issue a non-SCSI command, zfcp waits for
  11              5 seconds to get a free SBAL in the queue. Use this timeout
  12              as a trigger: If after 5 seconds there is no free SBAL,
  13              assume a stalled outbound queue and trigger recovery.
  14
  15 Acked-by: John Jolly <jjolly@suse.de>
  16 ---
  17  drivers/s390/scsi/zfcp_dbf.c |    2 +-
  18  drivers/s390/scsi/zfcp_fsf.c |    5 ++++-
  19  2 files changed, 5 insertions(+), 2 deletions(-)
  20
  21 --- a/drivers/s390/scsi/zfcp_fsf.c      2009-06-23 14:24:48.000000000 +0200
  22 +++ b/drivers/s390/scsi/zfcp_fsf.c      2009-06-23 14:26:00.000000000 +0200
  23 @@ -668,8 +668,11 @@ static int zfcp_fsf_req_sbal_get(struct
  24                                         zfcp_fsf_sbal_check(adapter), 5 * HZ);
  25         if (ret > 0)
  26                 return 0;
  27 -       if (!ret)
  28 +       if (!ret) {
  29                 atomic_inc(&adapter->qdio_outb_full);
  30 +               /* assume hanging outbound queue, try queue recovery */
  31 +               zfcp_erp_adapter_reopen(adapter, 0, 77, NULL);
  32 +       }
  33
  34         spin_lock_bh(&adapter->req_q_lock);
  35         return -EIO;
  36 --- a/drivers/s390/scsi/zfcp_dbf.c      2009-06-23 14:20:41.000000000 +0200
  37 +++ b/drivers/s390/scsi/zfcp_dbf.c      2009-06-23 14:25:50.000000000 +0200
  38 @@ -567,7 +567,7 @@ static const char *zfcp_rec_dbf_ids[] =
  39         [74]    = "unit recovery follow-up after successful port recovery",
  40         [75]    = "port recovery retry after failure",
  41         [76]    = "unit recovery retry after failure",
  42 -       [77]    = "",
  43 +       [77]    = "adapter reopen from queue stall",
  44         [78]    = "duplicate request id",
  45         [79]    = "link down",
  46         [80]    = "exclusive read-only unit access unsupported",