[Yaffs] Adjustments to mkyaffs2image to handle lost+found Is…

Hello All,

I'm working with the latest version of YAFFS2 as pulled from the git
repo, on Ubuntu kernel version 4.15.99. I am mounting an image of a
root filesystem created using mkyaffs2image, but at the mount point,
only the lost+found folder shows up.

After reading some archived posts, it seems this may be an issue with
how MTD uses the OOB areas versus how YAFFS2 uses the OOB areas.
However, it is not clear what I need to modify to make them play
nicely. I was under the impression that YAFFS2 could let the system
handle ECC, but I don't understand what I need to do to specify which
sections of the OOB are free to use.

I've verified that the NAND geometry matches in mkyaffs2image.c: The
page size (2048), erase block size/pages per block (64), and OOB
size(64) all match what I have in nandsim, as well as the output of
mtdinfo for the corresponding MTD.

Is there some other change I need to be making to create a valid image?

One additional piece of information that may be relevant: I had to
modify the source code to get YAFFS2 to load properly while compiling
this version of the kernel. Specifically, in the yaffs_readlink
method defined in yaffs_vfs_multi.c, I had to revert back to using
dentry->d_inode->i_op->readlink to populate the buffer, as
readlink_copy is no longer exported.

Thanks in advance for any advice you can provide.

Stephen