Re: BTRFS discard crash: failed to run delayed ref for logical 15506102321152 num_bytes 16384 type 182 action 2 ref_mod 1: -2 6.11.2)

[Marc MERLIN <marc_btrfs@merlins.org>]

On Fri, Apr 17, 2026 at 01:43:29PM +1000, David Disseldorp wrote:
> From the look of your block-dev path and loaded modules, the filesystem
> is atop a bcache caching layer. This would make it far from a simple
> dev topology; bcache would be expected to invalidate discarded cache
> regions regardless of underlying HDD discard support.
> Are you able to reproduce the bug if you remove the bcache layer?

Fair question, this used to an array running with bcache.
The cache has gone away, so it's running in degraded mode without cache,
with just an extra layer that hopefully does nothing.

That said, I reproduced this twice on both my laptops that are running
without raid5 and directly on ssd without bcache

All that said, thank you for making sure we're not missing some other
reason for a bug

Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
 
Home page: http://marc.merlins.org/                       | PGP 7F55D5F27AAF9D08