sdev
Block request made by scsi lld's to temporarily stop all scsi commands on the specified device. Called from interrupt or normal process context.
Returns zero if successful or error if not
This routine transitions the device to the SDEV_BLOCK state (which must be a legal transition). When the device is in this state, all commands are deferred until the scsi lld reenables the device with scsi_device_unblock or device_block_tmo fires. This routine assumes the host_lock is held on entry.
James Bottomley <James.Bottomley@hansenpartnership.com>
Rob Landley <rob@landley.net>