I am looking for understanding EXT3 filesystem source code. I think I need a little pre-digestion to fully understand the code. Can anyone please suggest some material(blog etc.) where I can get some basic understanding of the source code.
I don't know of any online resources that are going to be as helpful as this book: Understanding the Linux Kernel. Chapter 12 covers the Linux VFS layer, and Chapter 18 covers ext2/ext3 specifically.
The book probably about due for a fourth edition, since it's circa 2.6.10, but the basics are still the same. There's a lot going on in filesystems these days, though, so it'd be nice if the book covered ext4 and btrfs as well.