Understainding ext2fs library

Useful tool:

1. debugfs -R show_super_stats
2. Kernel hlist doesn't really do hash. You still need to write your own hash functions

Part 1: inode.c

1. get_next_blockgroup() doesn't really do the I/O. It just "gets ready" for reading the next block group.

Different asynchronous I/O methods in Linux

1. Library (aio_read, aio_write). This requires no kernel support. It just forks out a child process doing I/O. This is the "poor man's" version of asynchronous I/O
2. Kernel support. This is available in 2.6 kernel. It uses functions like io_setup, io_submit, io_getevents, etc..

How to use shared libraries in Linux

Note that LD_LIBRARY_PATH is to be set before the program run. In other words, the variable is to be used AT RUN TIME.