releases/4.14.110/scsi-zfcp-fix-rport-unblock-if-deleted-scsi-devices-on-scsi_host.patch

   1 From fe67888fc007a76b81e37da23ce5bd8fb95890b0 Mon Sep 17 00:00:00 2001
   2 From: Steffen Maier <maier@linux.ibm.com>
   3 Date: Tue, 26 Mar 2019 14:36:58 +0100
   4 Subject: scsi: zfcp: fix rport unblock if deleted SCSI devices on Scsi_Host
   5
   6 From: Steffen Maier <maier@linux.ibm.com>
   7
   8 commit fe67888fc007a76b81e37da23ce5bd8fb95890b0 upstream.
   9
  10 An already deleted SCSI device can exist on the Scsi_Host and remain there
  11 because something still holds a reference.  A new SCSI device with the same
  12 H:C:T:L and FCP device, target port WWPN, and FCP LUN can be created.  When
  13 we try to unblock an rport, we still find the deleted SCSI device and
  14 return early because the zfcp_scsi_dev of that SCSI device is not
  15 ZFCP_STATUS_COMMON_UNBLOCKED. Hence we miss to unblock the rport, even if
  16 the new proper SCSI device would be in good state.
  17
  18 Therefore, skip deleted SCSI devices when iterating the sdevs of the shost.
  19 [cf. __scsi_device_lookup{_by_target}() or scsi_device_get()]
  20
  21 The following abbreviated trace sequence can indicate such problem:
  22
  23 Area           : REC
  24 Tag            : ersfs_3
  25 LUN            : 0x4045400300000000
  26 WWPN           : 0x50050763031bd327
  27 LUN status     : 0x40000000     not ZFCP_STATUS_COMMON_UNBLOCKED
  28 Ready count    : n              not incremented yet
  29 Running count  : 0x00000000
  30 ERP want       : 0x01
  31 ERP need       : 0xc1           ZFCP_ERP_ACTION_NONE
  32
  33 Area           : REC
  34 Tag            : ersfs_3
  35 LUN            : 0x4045400300000000
  36 WWPN           : 0x50050763031bd327
  37 LUN status     : 0x41000000
  38 Ready count    : n+1
  39 Running count  : 0x00000000
  40 ERP want       : 0x01
  41 ERP need       : 0x01
  42
  43 ...
  44
  45 Area           : REC
  46 Level          : 4              only with increased trace level
  47 Tag            : ertru_l
  48 LUN            : 0x4045400300000000
  49 WWPN           : 0x50050763031bd327
  50 LUN status     : 0x40000000
  51 Request ID     : 0x0000000000000000
  52 ERP status     : 0x01800000
  53 ERP step       : 0x1000
  54 ERP action     : 0x01
  55 ERP count      : 0x00
  56
  57 NOT followed by a trace record with tag "scpaddy"
  58 for WWPN 0x50050763031bd327.
  59
  60 Signed-off-by: Steffen Maier <maier@linux.ibm.com>
  61 Fixes: 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN recovery")
  62 Cc: <stable@vger.kernel.org> #2.6.32+
  63 Reviewed-by: Jens Remus <jremus@linux.ibm.com>
  64 Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
  65 Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
  66 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  67
  68 ---
  69  drivers/s390/scsi/zfcp_erp.c |    3 +++
  70  1 file changed, 3 insertions(+)
  71
  72 --- a/drivers/s390/scsi/zfcp_erp.c
  73 +++ b/drivers/s390/scsi/zfcp_erp.c
  74 @@ -1306,6 +1306,9 @@ static void zfcp_erp_try_rport_unblock(s
  75                 struct zfcp_scsi_dev *zsdev = sdev_to_zfcp(sdev);
  76                 int lun_status;
  77
  78 +               if (sdev->sdev_state == SDEV_DEL ||
  79 +                   sdev->sdev_state == SDEV_CANCEL)
  80 +                       continue;
  81                 if (zsdev->port != port)
  82                         continue;
  83                 /* LUN under port of interest */