TAPSET::SCSI(3stap)													       TAPSET::SCSI(3stap)

NAME

       tapset::scsi - systemtap scsi probe points

DESCRIPTION

       This family of probe points is used to probe the SCSI activities.  It contains the following probe points:

       scsi.ioentry
	      Fires when SCSI mid layer prepares a SCSI request

	      Arguments:

	      disk_major
		The major number of the disk

	      disk_minor
		The minor number of the disk

	      device_state
		The current state of the device. The possible values could be:

		      SDEV_CREATED = 1,    /* device created but not added to sysfs
					    * Only internal commands allowed (for inq) */
		      SDEV_RUNNING = 2,    /* device properly configured
					    * All commands allowed */
		      SDEV_CANCEL = 3,	   /* beginning to delete device
					    * Only error handler commands allowed */
		      SDEV_DEL = 4,	   /* device deleted
					    * no commands allowed */
		      SDEV_QUIESCE = 5,    /* Device quiescent.  No block commands
					    * will be accepted, only specials (which
					    * originate in the mid-layer) */
		      SDEV_OFFLINE = 6,    /* Device offlined (by error handling or
					    * user request */
		      SDEV_BLOCK = 7,	   /* Device blocked by scsi lld.  No scsi
					    * commands from user or midlayer should be issued
					    * to the scsi lld. */

       scsi.iodispatching
	      Fires when the SCSI mid layer dispatches a SCSI command to the low level driver

	      Arguments:

	      host_no
		The host number

	      channel
		The channel number

	      lun
		The lun number

	      dev_id
		The scsi device id

	      device_state
		The current state of the device.

	      data_direction
		The data_direction specifies whether this command is from/to the device.
		The possible values could be:

		      DMA_BIDIRECTIONAL = 0,
		      DMA_TO_DEVICE = 1,
		      DMA_FROM_DEVICE = 2,
		      DMA_NONE = 3,

	      request_buffer
		The request buffer address

	      req_bufflen
		The request buffer length

       scsi.iodone
	      Fires when a SCSI command is done by low level driver and enqueued into the done queue.

	      Arguments:

	      host_no
		The host number

	      channel
		The channel number

	      lun
		The lun number

	      dev_id
		The scsi device id

	      device_state
		The current state of the device

	      data_direction
		The data_direction specifies whether this command is from/to the device.

       scsi.iocompleted
	      Fires when SCSI mid layer runs the completion processing for block device I/O requests

	      Arguments:

	      host_no
		The host number

	      channel
		The channel number

	      lun
		The lun number

	      dev_id
		The scsi device id

	      device_state
		The current state of the device

	      data_direction
		The data_direction specifies whether this command is from/to the device.

	      goodbytes
		The bytes completed.

SEE ALSO

       stap(1), stapprobes(3stap)

IBM
															       TAPSET::SCSI(3stap)