How does the inode map to data block of a file?

Question

Hello
How does the inode map to data block of a file?
please reply me. i am waiting for your reply.
Thanx

Answer 1

Inode has 13 block addresses. The first 10 are direct block addresses of the first 10 data blocks in the file. The 11th address points to a one-level index block. The 12th address points to a two-level (double in-direction) index block. The 13th address points to a three-level(triple in-direction)index block. This provides a very large maximum file size with efficient access to large files, but also small files are accessed directly in one disk read.