There's a really odd comment in that thing:
/*
* Unhashed alias is able to exist because of revalidate()
* called by lookup_fast. You can easily make this status
* by calling create and lookup concurrently
* In such case, we reuse an alias instead of new dentry
*/
and AFAICS it had been there since the original merge. What I don't
understand is how the hell could revalidate result in that -
exfat_d_revalidate() always returns 1 on any positive dentry and alias is
obviously positive (it has the same inode as the one we are about to use).
It mentions a way to reproduce that, but I don't understand what does
that refer to; could you give details?
