Re: [PATCH 2/4] fs/resctrl: Free mon_data structures on rdt_get_tree() failure

["Luck, Tony" <tony.luck@intel.com>]

On Sat, May 09, 2026 at 08:43:36PM +0800, Chen, Yu C wrote:
> On 5/9/2026 5:36 AM, Luck, Tony wrote:
> > On Fri, May 08, 2026 at 11:21:41AM -0700, Tony Luck wrote:
> > 
> >  From 0263035539f805f5d4bddcef8968b551354cb86d Mon Sep 17 00:00:00 2001
> > From: Tony Luck <tony.luck@intel.com>
> > Date: Thu, 7 May 2026 13:48:51 -0700
> > Subject: [PATCH] fs/resctrl: Free mon_data structures on rdt_get_tree()
> >   failure
> > 
> > If mkdir_mondata_all() succeeds but a subsequent call in rdt_get_tree()
> > fails, the mon_data structures allocated by mon_get_kn_priv() are
> > leaked. Add mon_put_kn_priv() to the out_mongrp error path to free
> > them.
> > 
> > Fixes: ee4f0ec938ad ("fs/resctrl: Simplify allocation of mon_data structures")
> 
> I did not find above commit in vanilla kernel, should it be 2a6566038544
> ("x86/resctrl:
> Expand the width of domid by replacing mon_data_bits") where
> mon_put_kn_priv() was introduced?

Thanks for the catch. Another strike against Claude. It didn't hallucinate
this commit for the fixes tag, that commit does appear in my local repo.
But in a dead-end branch I created to write the patch. I posted it here
in v3 of my telemetry series:

https://lore.kernel.org/all/20250407234032.241215-2-tony.luck@intel.com/

But James Morse picked it up in v11 of his "Move resctrl filessytem code
to fs/resctrl" series:

https://lore.kernel.org/all/20250513171547.15194-13-james.morse@arm.com/

where it was applied upstream in the 2a6566038544 commit you found.

I'm somewhat confused that Claude dug through my other branches instead
of just looking for ancestors of the current branch. Maybe I need an
explicit instruction to AI agents on how to find commits to use for
Fixes: tags?

Claude is now double-fired.

-Tony