[Unionfs] unionfs error

[Torsten Luettgert]

On Di, 2006-11-07 at 09:47 -0500, Vineet Chadha wrote:
> Hi there,
> 
> I am using kernel 2.6.18.1 and getting following error with unionfs-1.4.
> Please help.

Nah, you're not using 2.6.18.1, but the heavily modified Fedora Kernel
(like I do). It's really surprising how much they changed it.

I use FC6, not FC5, but I guess the kernel is pretty much the same.
Three problems come up:

- there's no linux/config.h (the kernel guys added some make target
  for generating the user land headers, and that's what is included
  in FC kernels. Apparently, config.h is not included).
  But it's not needed anyway. Just comment out the 
  #include <linux/config.h> lines (one in unionfs.h, one in
  stale_inode.c)

- Fedora's struct inode doesn't have i_blksize. Since unionfs.h, line
  520 is the only place it's referenced in unionfs, and the function
  just copies a struct inode, I commented that line out, too.
  Had a bit of a bad feeling about it, but it seems to work.

- What I didn't grok is the third problem:
  dirhelper.c:266: warning: passing argument 2 of ‘vfs_readdir’ from
  incompatible pointer type.
  Well, according to linux/fs.h, the 2nd argument is a filldir_t, which
  is typedef'd to the exact signature of readdir_util_callback.
  To work around it, just remove the two "-Werror" options from the
  Makefile.

Then unionfs will at least compile. I did some basic playing around,
but no heavy duty testing, so no idea if those changes leave it stable.

Regards,
Torsten