On Wed, Oct 24, 2018 at 5:19 AM Ketil Froyn <ketil@froyn.name> wrote:

> Hi,
>
> I'm trying to get yaffs2 working on an Ubuntu VM for a proof of
> concept, and after trying the bundled kernels with the current release
> (Ubuntu 18.04) I looked at the kernel versions and gave Ubuntu 12.04
> with kernel 3.2.79 a try. Yaffs2 (commit 3439fa4) compiled fine with
> the 3.2.79 kernel. So I installed the new kernel with yaffs2 support,
> and created a nandsim device which I mounted  with yaffs2 (just an
> empty filesystem). This seemed to be working fine.
>
> However, when did something trivial like "ls -l" in the yaffs2 mount,
> ls failed with the message "Killed". It turns out that a call to
> lgetxattr() failed with a kernel oops. This happened every time. I've
> attached a stack trace of such an oops.
>
> I tried disabling yaffs xattr support during make menuconfig, but this
> doesn't appear to really switch xattr support off, despite the config
> variable being disabled in the .config file:
>
> # CONFIG_YAFFS_XATTR is not set
>
> I attempted to _really_ disable xattr support with this patch,
> successfully this time:
>
> --- a/yaffs_vfs_multi.c
> +++ b/yaffs_vfs_multi.c
> @@ -240,9 +240,11 @@ MODULE_PARM(yaffs_gc_control, "i");
>  #define YAFFS_USE_DIR_ITERATE
>  #endif
>
> +#if 0
>  #if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 0))
>  #define YAFFS_USE_XATTR
>  #endif
> +#endif
>
>  #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,12,0))
>  #define YAFFS_NEW_PROCFS
>
>
> Now things appear to be working much better. Calls to lgetxattr()
> return EOPNOTSUPP, and everything works.
>
> So I suspect there are two issues at play here:
>
> 1. DIsabling yaffs xattr support in the kernel config doesn't really
> disable it
> 2. There's a kernel oops in the xattr code
>

Thanks Ketil

I will add those to my todo list.

-- CHarles