Re: [PATCH v0 00/42] notifiers: Return an error when callback is already registered

On Mon, Nov 08, 2021 at 09:17:03AM -0500, Alan Stern wrote:

What reason is there for moving the check into the callers? It seems like pointless churn. Why not add the error return code, change the WARN to pr_warn, and leave the callers as they are? Wouldn't that end up having exactly the same effect?

For that matter, what sort of remedial action can a caller take if the return code is -EEXIST? Is there any point in forcing callers to check the return code if they can't do anything about it?

See my reply to Geert from just now:

https://lore.kernel.org/r/YYkyUEqcsOwQMb1S@zn.tnic

I guess I can add another indirection to notifier_chain_register() and avoid touching all the call sites.