(NAND) JFFS2 mount time

David Woodhouse dwmw2 at infradead.org
Wed Jun 16 20:25:40 EDT 2004

On Tue, 2004-06-15 at 08:52 +0200, Ferenc Havasi wrote:
> About our idea/plan: we would like to modify the mkfs and umount porcess
> to store some extra information (inode_cache). 

I wasn't going to do it on umount. I was going to do it at the end of
each eraseblock. When we've almost filled an eraseblock we write a
summary to the end of it, containing all the information which we would
otherwise have to read from it during mount.

That's basically a list of the { inode#, physical_offset, length } for
each node in the eraseblock, and something about nlink. Note that
there's a lot of redundancy in the offsets and lengths so we can
contrive a storage method which is fairly efficient. 

Then at mount we look first at the _end_ of each eraseblock for such a
summary. If it exists, we read in the state from it. If not, we scan
that particular eraseblock the old way.


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