On Fri, 22 Aug 2014 21:39:42 +0530, manoj kumar said:
i am new to kernelnewbie. I would like to work on the VFS/Filesystem sub system. Any guidance towards the same is much appreciated.
Step 0: Figure out *why* you want to work on filesystems, pick a *specific* goal, and pick up a basic understanding of filesystem design. For this, it's helpful to look at how a number of different filesystems (not all Linux) have been designed - everything from the ext[234] series, to SGI's xfs, to Microsoft's NTFS. Looking at old mainframe designs (like the VTOC/catalog setup used on IBM's OS/360 through MVS systems) can help as well (you think "extents" in ext are a new thing? OS/360 used those way back in 1964: http://pic.dhe.ibm.com/infocenter/zos/v2r1/topic/com.ibm.zos.v2r1.idas300/ds... Things to focus on - tradeoffs that have to be made, and why given systems make given choices. There's good reasons why ext1 and ext2 *didn't* use extents - and good reasons why ext4 does. You need to understand stuff like that.