RE: [PATCH v2] pNFS: deadlock in pnfs_send_layoutreturn

[Ben Roberts]

Hi Ben,

> The kzalloc failure is definitely a rarely-used/tested path, so its possible
> there's an issue there no one has seen yet, but from what I can see it looks
> like every call to pnfs_send_layoutreturn() first calls
> pnfs_prepare_layoutreturn(), which already clears
> NFS_LAYOUT_RETURN_REQUESTED. I don't see how you can end up with another
> proccess seeing the flag.

Understood, thank you for the feedback here. I withdraw the patch request and
will take this back to the drawing board. Likely removing the patch from local
systems and looking to capture more useful diagnostics if/when the problem
reoccurs. 

> There's at least one body of work in this area that your systems
> don't yet have:
> https://lore.kernel.org/linux-nfs/20240613050055.854323-1-trond.myklebust@xxxxxxxxxxxxxxx/

For what it's worth, I checked this patch set and the changes are almost
completely present in the EL source. Patch 2 is only partially applied. 

Ben Roberts

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