If a fail command error is injected, set the command's status and sense
data then finish this SCSI command.

Set SCSI command's status and sense data format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x2                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error Count                                           |
  |        |      |  0: the rule will be ignored                          |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+
  |   4    |  x8  | Host byte in scsi_cmd::status                         |
  |        |      | [scsi_cmd::status has 32 bits holding these 3 bytes]  |
  +--------+------+-------------------------------------------------------+
  |   5    |  x8  | Driver byte in scsi_cmd::status                       |
  +--------+------+-------------------------------------------------------+
  |   6    |  x8  | SCSI Status byte in scsi_cmd::status                  |
  +--------+------+-------------------------------------------------------+
  |   7    |  x8  | SCSI Sense Key in scsi_cmnd                           |
  +--------+------+-------------------------------------------------------+
  |   8    |  x8  | SCSI ASC in scsi_cmnd                                 |
  +--------+------+-------------------------------------------------------+
  |   9    |  x8  | SCSI ASCQ in scsi_cmnd                                |
  +--------+------+-------------------------------------------------------+

Examples:
    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "2 -10 0x88 0 0 0x2 0x3 0x11 0x0" >${error}

will make device's read command return with media error with additional
sense of "Unrecovered read error" (UNC):
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-7-haowenchao2@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>