Commit 33592274 authored by Wenchao Hao's avatar Wenchao Hao Committed by Martin K. Petersen
Browse files

scsi: scsi_debug: Set command result and sense data if error is injected 



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: default avatarDouglas Gilbert <dgilbert@interlog.com>
Signed-off-by: default avatarWenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-7-haowenchao2@huawei.com


Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 33bccf55

drivers/scsi/scsi_debug.c

+53 −0
Original line number Diff line number Diff line
@@ -7797,6 +7797,48 @@ static int sdebug_fail_queue_cmd(struct scsi_cmnd *cmnd) 
	return 0;

}



static int sdebug_fail_cmd(struct scsi_cmnd *cmnd, int *retval,

			   struct sdebug_err_inject *info)

{

	struct scsi_device *sdp = cmnd->device;

	struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;

	struct sdebug_err_inject *err;

	unsigned char *cmd = cmnd->cmnd;

	int ret = 0;

	int result;



	if (devip == NULL)

		return 0;



	rcu_read_lock();

	list_for_each_entry_rcu(err, &devip->inject_err_list, list) {

		if (err->type == ERR_FAIL_CMD &&

		    (err->cmd == cmd[0] || err->cmd == 0xff)) {

			if (!err->cnt) {

				rcu_read_unlock();

				return 0;

			}



			ret = !!err->cnt;

			rcu_read_unlock();

			goto out_handle;

		}

	}

	rcu_read_unlock();



	return 0;



out_handle:

	if (err->cnt < 0)

		err->cnt++;

	mk_sense_buffer(cmnd, err->sense_key, err->asc, err->asq);

	result = err->status_byte | err->host_byte << 16 | err->driver_byte << 24;

	*info = *err;

	*retval = schedule_resp(cmnd, devip, result, NULL, 0, 0);



	return ret;

}



static int scsi_debug_queuecommand(struct Scsi_Host *shost,

				   struct scsi_cmnd *scp)

{
@@ -7817,6 +7859,7 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost, 
	bool has_wlun_rl;

	bool inject_now;

	int ret = 0;

	struct sdebug_err_inject err;



	scsi_set_resid(scp, 0);

	if (sdebug_statistics) {
@@ -7869,6 +7912,16 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost, 
		return ret;

	}



	if (sdebug_fail_cmd(scp, &ret, &err)) {

		scmd_printk(KERN_INFO, scp,

			"fail command 0x%x with hostbyte=0x%x, "

			"driverbyte=0x%x, statusbyte=0x%x, "

			"sense_key=0x%x, asc=0x%x, asq=0x%x\n",

			opcode, err.host_byte, err.driver_byte,

			err.status_byte, err.sense_key, err.asc, err.asq);

		return ret;

	}



	if (unlikely(inject_now && !atomic_read(&sdeb_inject_pending)))

		atomic_set(&sdeb_inject_pending, 1);