Re: [PATCH 1/2] kernfs_path_from_node_locked: don't overwrite nlen

[Tejun Heo]

On Sun, Apr 17, 2016 at 03:04:31PM -0500, serge.hallyn@xxxxxxxxxx wrote:
> From: Serge Hallyn <serge.hallyn@xxxxxxxxxx>
> 
> We've calculated @len to be the bytes we need for '/..' entries from
> @kn_from to the common ancestor, and calculated @nlen to be the extra
> bytes we need to get from the common ancestor to @kn_to.  We use them
> as such at the end.  But in the loop copying the actual entries, we
> overwrite @nlen.  Use a temporary variable for that instead.
> 
> Without this, the return length, when the buffer is large enough, is
> wrong.  (When the buffer is NULL or too small, the returned value is
> correct. The buffer contents are also correct.)
> 
> Interestingly, no callers of this function are affected by this as of
> yet.  However the upcoming cgroup_show_path() will be.
> 
> Signed-off-by: Serge Hallyn <serge.hallyn@xxxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Greg, can you please pick this one up for v4.6?

Thanks.

-- 
tejun