stapprobes.scsi

STAPPROBES.SCSI(5)					   STAPPROBES.SCSI(5)



NAME
       stapprobes.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	 han-
	      dling 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(5),




IBM				  2009-04-20		   STAPPROBES.SCSI(5)