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.TH TAPSET::SCSI 3stap "" "IBM"
.SH NAME
tapset::scsi \- systemtap scsi probe points

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.SH DESCRIPTION

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

.P
.TP 
.B scsi.ioentry
Fires when SCSI mid layer prepares a SCSI request

.B Arguments:

.I disk_major
  The major number of the disk

.I disk_minor
  The minor number of the disk

.I 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. */

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

.B Arguments:

.I host_no
  The host number

.I channel
  The channel number

.I lun
  The lun number

.I dev_id
  The scsi device id

.I device_state
  The current state of the device. 

.I 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,

.I request_buffer
  The request buffer address

.I req_bufflen
  The request buffer length

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

.B Arguments:

.I host_no
  The host number

.I channel
  The channel number

.I lun
  The lun number

.I dev_id
  The scsi device id

.I device_state
  The current state of the device

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

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

.B Arguments:

.I host_no
  The host number

.I channel
  The channel number

.I lun
  The lun number

.I dev_id
  The scsi device id

.I device_state
  The current state of the device

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

.I goodbytes
  The bytes completed.

.SH SEE ALSO
.IR stap (1),
.IR stapprobes (3stap)