On 11/25/25 12:54, Nilay Shroff wrote:

On 11/25/25 5:00 PM, Christoph Hellwig wrote:

quoted

On Tue, Nov 25, 2025 at 04:58:32PM +0530, Nilay Shroff wrote:

quoted

quoted

From git history, I see that was added to avoid memory reclaim  to avoid

possible circular locking dependency. This commit 83e1226b0ee2 ("nvme-tcp:
fix possible circular locking when deleting a controller under memory
pressure") adds it.

I suspect this was intended to be noio, and we should just switch to
that.

Yeah, I agree that this should be changed to noio. However, it seems that
this alone may not be sufficient to fix the lockdep splat reported here.
Since the real work of fput() might be deferred to another thread, using a noio
scope in this path may not have the intended effect and could end up being
redundant.

That said, I noticed another fix from Chaitanya [1], where fput() is replaced
with __fput_sync(). With that change in place, combining the noio scope adjustment
with the switch to __fput_sync() should indeed address the lockdep issue. Given
that both problems have very similar lockdep signatures, it might make sense to
merge these two changes into a single fix.

[1] https://lore.kernel.org/all/20251125005950.41046-1-ckulkarnilinux@gmail.com/ (local)

Yes, we should.
Both address similar symptoms, and I wouldn't be surprised both turn out
to address the same issue.
(Frame #0 from here is basically identical to frame #2 in the referenced
issue).

So please roll both into one patch.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
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