[Dazuko-devel] nullfs 0.0.4 posted

[John Ogness]

Hi,

I've posted version 0.0.4 of nullfs. This version supports Linux
2.6.26. The only real code change was that the d_compare dentry
operation is now also hooked.

As I go through each of the files, I am making sure that all
operations are hooked that are used by other filesystems. (Currently,
I have only completed going through dentry.c.)

The only problem I've encountered with nullfs is its lack of support
for mmap writes. This is mentioned in the README under "KNOWN ISSUES"
but is a real problem if an application needs this. It is particularly
a problem because the application does not know that the writes are
failing. (!!)

I was recently burned by this problem. After spending hours trying to
figure out why the uImage's I created with mkimage were corrupt, I
finally realized it was because I was generating the images on a
nullfs mount and mkimage uses mmap write's.

I would like to implement nullfs so that a mmap() with write access
fails. (At least until mmap write is suppported.)

John Ogness

-- 
Dazuko Maintainer