Commit 32be8b6e authored Oct 10, 2023 by Wenchao Hao Committed by Martin K. Petersen Oct 16, 2023

scsi: scsi_debug: Time out command if the error is injected



If a timeout error is injected, return 0 from scsi_debug_queuecommand to
make the command time out.

Time out SCSI command format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x0                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this 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            |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "0 -10 0x12" > ${error}

will make the device's inquiry command time out 10 times.

    echo "0 1 0x12" > ${error}

will make the device's inquiry time out each time it is invoked on this
device.

Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-5-haowenchao2@huawei.com


Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

parent 962d77cd

drivers/scsi/scsi_debug.c

+34 −0

Original line number	Diff line number	Diff line
		@@ -7741,6 +7741,34 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
		return num_entries;
		}

		static int sdebug_timeout_cmd(struct scsi_cmnd *cmnd)
		{
		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;

		if (devip == NULL)
		return 0;

		rcu_read_lock();
		list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
		if (err->type == ERR_TMOUT_CMD &&
		(err->cmd == cmd[0] \|\| err->cmd == 0xff)) {
		ret = !!err->cnt;
		if (err->cnt < 0)
		err->cnt++;

		rcu_read_unlock();
		return ret;
		}
		}
		rcu_read_unlock();

		return 0;
		}

		static int scsi_debug_queuecommand(struct Scsi_Host *shost,
		struct scsi_cmnd *scp)
		{
		@@ -7799,6 +7827,12 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost,
		if (NULL == devip)
		goto err_out;
		}

		if (sdebug_timeout_cmd(scp)) {
		scmd_printk(KERN_INFO, scp, "timeout command 0x%x\n", opcode);
		return 0;
		}

		if (unlikely(inject_now && !atomic_read(&sdeb_inject_pending)))
		atomic_set(&sdeb_inject_pending, 1);