scsi_device_quiesce — Block user issued commands.
|struct scsi_device * sdev|
This works by trying to transition to the SDEV_QUIESCE state (which must be a legal transition). When the device is in this state, only special requests will be accepted, all others will be deferred. Since special requests may also be requeued requests, a successful return doesn't guarantee the device will be totally quiescent.
Must be called with user context, may sleep.
Returns zero if unsuccessful or an error if not.