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Subject: Re: [PATCH v1 2/3] Treewide: Stop corrupting socket's task_frag
From:   Jeff Layton <jlayton@kernel.org>
To:     Christoph Hellwig <hch@lst.de>,
        Benjamin Coddington <bcodding@redhat.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
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Date:   Tue, 29 Nov 2022 12:42:33 -0500
In-Reply-To: <20221129140242.GA15747@lst.de>
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On Tue, 2022-11-29 at 15:02 +0100, Christoph Hellwig wrote:
> Hmm.  Having to set a flag to not accidentally corrupt per-task
> state seems a bit fragile.  Wouldn't it make sense to find a way to opt
> into the feature only for sockets created from the syscall layer?

I agree that that would be cleaner. task_frag should have been an opt-in
thing all along. That change regressed all of the in-kernel users of
sockets.

Where would be the right place to set that flag for only userland
sockets? A lot of the in-kernel socket users hook into the socket API at
a fairly high-level. 9P and CIFS, for instance, call __sock_create.

We could set it in the syscall handlers (and maybe in iouring) I
suppose, but that seems like the wrong thing to do too.

In the absence of a clean place to do this, I think we're going to be
stuck doing it the way Ben has proposed...
--=20
Jeff Layton <jlayton@kernel.org>