Re: [PATCH v2] fs: Add VirtualBox guest shared folder (vboxsf) support

[Al Viro]

* what hch said about mount options.  Get rid of that before the thing
  goes into mainline.

* all "inode = GET_F_DENTRY(f)->d_inode;" are complete BS; it's called
  file_inode(f).  Kill GET_F_DENTRY() off and be done with that.

* your ->rename() can race with ->get_link().  Look at the place where
  the former reassigns ->path and frees the old value and think what
  happens if the latter is called just prior to that kfree().

* the same goes for sf_inode_revalidate() vs. rename().

* just what happens to ->path of inode when e.g. its grandparent
  directory is renamed?

* AFAICS, you consider all negative dentries invalid.  Why do you even
  hash them, then?