Linux Kernel readlink equivalent

Hello, I'm working on some linux kernel driver stuff and I have a fake path called /dev/blah/whatever that points to /dev/block/real_device. The issue is that lookup_bdev will fail to follow the symlink so I'd like to massage the path upfront by getting the real path (/dev/block/real_device) so I can hand that off to lookup_bdev so it returns successfully instead of an error. Or any other kernel call that would correctly retrieve the block_device information given the initial path which is a symlink. Note: I saw that the tomoyo module has something like that but I was looking for the generic implementation of the kernel if one exists. Thanks David