Kalinka is a Russian song written in 1860 by composer and folklorist Ivan Larionov. The song 'Darling' in Vishal Bhardwaj's 7 Khoon Maaf is based on the song only. To make it all the more visible, Vishal has kept the words 'Kalinka Kalinka Kalinka Moya' as is in the other version of the song, Doosri Darling.
The meaning of the lines, found from Wikipedia, is as follows:
Kalinka, kalinka, kalinka moya!
V sadu yagoda malinka, malinka moya!
Little snowberry, snowberry, snowberry of mine!
Little raspberry in the garden, my little raspberry!