Re: RCU stalls and GPFs in ceph/netfs

From: Max Kellermann
Date: Mon Jul 29 2024 - 05:19:02 EST


On Sun, Jul 28, 2024 at 12:49 PM Max Kellermann
<max.kellermann@xxxxxxxxx> wrote:
> in the last few days, I have been chasing a 6.10 regression. After
> updating one of our servers from 6.9.10 to 6.10.1, I found various
> problems that may or may not be caused by the same code change
> (abbreviated):

Today, I gave this another try and it turned out to be a simple
leftover folio_end_private_2() call. It was really caused by commit
ae678317b95e ("netfs: Remove deprecated use of PG_private_2 as a
second writeback flag"), after all.

I posted two candidate patches which both fix this bug;

Minimal fix: https://lore.kernel.org/lkml/20240729090639.852732-1-max.kellermann@xxxxxxxxx/
Fix which removes a bunch of obsolete code:
https://lore.kernel.org/lkml/20240729091532.855688-1-max.kellermann@xxxxxxxxx/

You decide which one you prefer.

Max