releases/4.14.53/scsi-zfcp-fix-missing-scsi-trace-for-result-of-eh_host_reset_handler.patch

   1 From df30781699f53e4fd4c494c6f7dd16e3d5c21d30 Mon Sep 17 00:00:00 2001
   2 From: Steffen Maier <maier@linux.ibm.com>
   3 Date: Thu, 17 May 2018 19:14:43 +0200
   4 Subject: scsi: zfcp: fix missing SCSI trace for result of eh_host_reset_handler
   5
   6 From: Steffen Maier <maier@linux.ibm.com>
   7
   8 commit df30781699f53e4fd4c494c6f7dd16e3d5c21d30 upstream.
   9
  10 For problem determination we need to see whether and why we were successful
  11 or not. This allows deduction of scsi_eh escalation.
  12
  13 Example trace record formatted with zfcpdbf from s390-tools:
  14
  15 Timestamp      : ...
  16 Area           : SCSI
  17 Subarea        : 00
  18 Level          : 1
  19 Exception      : -
  20 CPU ID         : ..
  21 Caller         : 0x...
  22 Record ID      : 1
  23 Tag            : schrh_r        SCSI host reset handler result
  24 Request ID     : 0x0000000000000000                     none (invalid)
  25 SCSI ID        : 0xffffffff                             none (invalid)
  26 SCSI LUN       : 0xffffffff                             none (invalid)
  27 SCSI LUN high  : 0xffffffff                             none (invalid)
  28 SCSI result    : 0x00002002     field re-used for midlayer value: SUCCESS
  29                                 or in other cases: 0x2009 == FAST_IO_FAIL
  30 SCSI retries   : 0xff                                   none (invalid)
  31 SCSI allowed   : 0xff                                   none (invalid)
  32 SCSI scribble  : 0xffffffffffffffff                     none (invalid)
  33 SCSI opcode    : ffffffff ffffffff ffffffff ffffffff    none (invalid)
  34 FCP rsp inf cod: 0xff                                   none (invalid)
  35 FCP rsp IU     : 00000000 00000000 00000000 00000000    none (invalid)
  36                  00000000 00000000
  37
  38 v2.6.35 commit a1dbfddd02d2 ("[SCSI] zfcp: Pass return code from
  39 fc_block_scsi_eh to scsi eh") introduced the first return with something
  40 other than the previously hardcoded single SUCCESS return path.
  41
  42 Signed-off-by: Steffen Maier <maier@linux.ibm.com>
  43 Fixes: a1dbfddd02d2 ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
  44 Cc: <stable@vger.kernel.org> #2.6.38+
  45 Reviewed-by: Jens Remus <jremus@linux.ibm.com>
  46 Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
  47 Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
  48 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  49
  50 ---
  51  drivers/s390/scsi/zfcp_dbf.c  |   40 ++++++++++++++++++++++++++++++++++++++++
  52  drivers/s390/scsi/zfcp_ext.h  |    2 ++
  53  drivers/s390/scsi/zfcp_scsi.c |   11 ++++++-----
  54  3 files changed, 48 insertions(+), 5 deletions(-)
  55
  56 --- a/drivers/s390/scsi/zfcp_dbf.c
  57 +++ b/drivers/s390/scsi/zfcp_dbf.c
  58 @@ -664,6 +664,46 @@ void zfcp_dbf_scsi(char *tag, int level,
  59         spin_unlock_irqrestore(&dbf->scsi_lock, flags);
  60  }
  61
  62 +/**
  63 + * zfcp_dbf_scsi_eh() - Trace event for special cases of scsi_eh callbacks.
  64 + * @tag: Identifier for event.
  65 + * @adapter: Pointer to zfcp adapter as context for this event.
  66 + * @scsi_id: SCSI ID/target to indicate scope of task management function (TMF).
  67 + * @ret: Return value of calling function.
  68 + *
  69 + * This SCSI trace variant does not depend on any of:
  70 + * scsi_cmnd, zfcp_fsf_req, scsi_device.
  71 + */
  72 +void zfcp_dbf_scsi_eh(char *tag, struct zfcp_adapter *adapter,
  73 +                     unsigned int scsi_id, int ret)
  74 +{
  75 +       struct zfcp_dbf *dbf = adapter->dbf;
  76 +       struct zfcp_dbf_scsi *rec = &dbf->scsi_buf;
  77 +       unsigned long flags;
  78 +       static int const level = 1;
  79 +
  80 +       if (unlikely(!debug_level_enabled(adapter->dbf->scsi, level)))
  81 +               return;
  82 +
  83 +       spin_lock_irqsave(&dbf->scsi_lock, flags);
  84 +       memset(rec, 0, sizeof(*rec));
  85 +
  86 +       memcpy(rec->tag, tag, ZFCP_DBF_TAG_LEN);
  87 +       rec->id = ZFCP_DBF_SCSI_CMND;
  88 +       rec->scsi_result = ret; /* re-use field, int is 4 bytes and fits */
  89 +       rec->scsi_retries = ~0;
  90 +       rec->scsi_allowed = ~0;
  91 +       rec->fcp_rsp_info = ~0;
  92 +       rec->scsi_id = scsi_id;
  93 +       rec->scsi_lun = (u32)ZFCP_DBF_INVALID_LUN;
  94 +       rec->scsi_lun_64_hi = (u32)(ZFCP_DBF_INVALID_LUN >> 32);
  95 +       rec->host_scribble = ~0;
  96 +       memset(rec->scsi_opcode, 0xff, ZFCP_DBF_SCSI_OPCODE);
  97 +
  98 +       debug_event(dbf->scsi, level, rec, sizeof(*rec));
  99 +       spin_unlock_irqrestore(&dbf->scsi_lock, flags);
 100 +}
 101 +
 102  static debug_info_t *zfcp_dbf_reg(const char *name, int size, int rec_size)
 103  {
 104         struct debug_info *d;
 105 --- a/drivers/s390/scsi/zfcp_ext.h
 106 +++ b/drivers/s390/scsi/zfcp_ext.h
 107 @@ -52,6 +52,8 @@ extern void zfcp_dbf_san_res(char *, str
 108  extern void zfcp_dbf_san_in_els(char *, struct zfcp_fsf_req *);
 109  extern void zfcp_dbf_scsi(char *, int, struct scsi_cmnd *,
 110                           struct zfcp_fsf_req *);
 111 +extern void zfcp_dbf_scsi_eh(char *tag, struct zfcp_adapter *adapter,
 112 +                            unsigned int scsi_id, int ret);
 113
 114  /* zfcp_erp.c */
 115  extern void zfcp_erp_set_adapter_status(struct zfcp_adapter *, u32);
 116 --- a/drivers/s390/scsi/zfcp_scsi.c
 117 +++ b/drivers/s390/scsi/zfcp_scsi.c
 118 @@ -323,15 +323,16 @@ static int zfcp_scsi_eh_host_reset_handl
 119  {
 120         struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scpnt->device);
 121         struct zfcp_adapter *adapter = zfcp_sdev->port->adapter;
 122 -       int ret;
 123 +       int ret = SUCCESS, fc_ret;
 124
 125         zfcp_erp_adapter_reopen(adapter, 0, "schrh_1");
 126         zfcp_erp_wait(adapter);
 127 -       ret = fc_block_scsi_eh(scpnt);
 128 -       if (ret)
 129 -               return ret;
 130 +       fc_ret = fc_block_scsi_eh(scpnt);
 131 +       if (fc_ret)
 132 +               ret = fc_ret;
 133
 134 -       return SUCCESS;
 135 +       zfcp_dbf_scsi_eh("schrh_r", adapter, ~0, ret);
 136 +       return ret;
 137  }
 138
 139  struct scsi_transport_template *zfcp_scsi_transport_template;