+/**
+ * sg_scsi_ioctl -- handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
+ * @file: file this ioctl operates on (optional)
+ * @q: request queue to send scsi commands down
+ * @disk: gendisk to operate on (option)
+ * @sic: userspace structure describing the command to perform
+ *
+ * Send down the scsi command described by @sic to the device below
+ * the request queue @q. If @file is non-NULL it's used to perform
+ * fine-grained permission checks that allow users to send down
+ * non-destructive SCSI commands. If the caller has a struct gendisk
+ * available it should be passed in as @disk to allow the low level
+ * driver to use the information contained in it. A non-NULL @disk
+ * is only allowed if the caller knows that the low level driver doesn't
+ * need it (e.g. in the scsi subsystem).
+ *
+ * Notes:
+ * - This interface is deprecated - users should use the SG_IO
+ * interface instead, as this is a more flexible approach to
+ * performing SCSI commands on a device.
+ * - The SCSI command length is determined by examining the 1st byte
+ * of the given command. There is no way to override this.
+ * - Data transfers are limited to PAGE_SIZE
+ * - The length (x + y) must be at least OMAX_SB_LEN bytes long to
+ * accommodate the sense buffer when an error occurs.
+ * The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
+ * old code will not be surprised.
+ * - If a Unix error occurs (e.g. ENOMEM) then the user will receive
+ * a negative return and the Unix error code in 'errno'.
+ * If the SCSI command succeeds then 0 is returned.
+ * Positive numbers returned are the compacted SCSI error codes (4
+ * bytes in one int) where the lowest byte is the SCSI status.
+ */