centos man page for register_blkdev

REGISTER_BLKDEV(9)						   Block Devices						REGISTER_BLKDEV(9)

NAME
       register_blkdev - register a new block device

SYNOPSIS
       int register_blkdev(unsigned int major, const char * name);

ARGUMENTS
       major
	   the requested major device number [1..255]. If major=0, try to allocate any unused major number.

       name
	   the name of the new block device as a zero terminated string

DESCRIPTION
       The name must be unique within the system.

       The return value depends on the major input parameter. - if a major device number was requested in range [1..255] then the function returns
       zero on success, or a negative error code - if any unused major number was requested with major=0 parameter then the return value is the
       allocated major number in range [1..255] or a negative error code otherwise

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							REGISTER_BLKDEV(9)