On Wed, Jun 22, 2016 at 04:35:07PM +0200, Miklos Szeredi wrote:
> Store in memory pointed to by ->d_fsdata. Use ->d_allocate() to allocate
> the storage.
>
> We could cast ->d_fsdata directly on 64bit archs, but I don't think this is
> worth the extra complexity.
Now, _that_ is interesting:
> +static void fuse_dentry_release(struct dentry *dentry)
> +{
> + kfree(dentry->d_fsdata);
> +}
What happens to fuse_dentry_revalidate() called on dentry in process of
getting dropped? Unlike freeing struct dentry itself, ->d_release() is
not RCU-delayed. So you are risking dereference of ->d_fsdata after
kfree(); at the very least, it needs RCU-delayed freeing...
