From: Rusty Russell <rusty@rustcorp.com.au>
To: Max Krasnyansky <maxk@qualcomm.com>
Cc: "David S. Miller" <davem@redhat.com>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Jean Tourrilhes <jt@bougret.hpl.hp.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH/RFC] New module refcounting for net_proto_family
Date: Wed, 19 Feb 2003 14:54:21 +1100 [thread overview]
Message-ID: <20030219035559.7527A2C079@lists.samba.org> (raw)
In-Reply-To: Your message of "Tue, 18 Feb 2003 10:50:49 -0800." <5.1.0.14.2.20030218101309.048d4288@mail1.qualcomm.com>
In message <5.1.0.14.2.20030218101309.048d4288@mail1.qualcomm.com> you write:
> At 07:46 PM 2/17/2003, David S. Miller wrote:
>
> >After talking to Alexey, I don't like this patch.
> >
> >The new module subsystem was supposed to deal with things
> >like this cleanly, and this patch is merely a hack to cover
> >up for it's shortcomings.
I don't quite understand.
There are some issue with this patch, however.
Firstly, the owner field should probably be in struct proto_ops not
struct socket, where the function pointers are.
The sk thing looks reasonable at first glance. Getting a reference to
npf->owner, then holding it for the socket is a little confusing, but
an obvious optimization over a naive "get, use, drop, get".
In sys_accept:
> @@ -1196,9 +1198,13 @@
> if (!(newsock = sock_alloc()))
> goto out_put;
>
> - newsock->type = sock->type;
> - newsock->ops = sock->ops;
> + newsock->type = sock->type;
> + newsock->ops = sock->ops;
> + newsock->owner = sock->owner;
>
> + try_module_get(sock->owner);
> + newsock->owner = sock->owner;
> +
> err = sock->ops->accept(sock, newsock, sock->file->f_flags);
> if (err < 0)
> goto out_release;
You still need to check the result of try_module_get, and fail if it
fails. The *only* time this will fail is when someone is doing an
"rmmod --wait" on the module, which presumably means they really do
not want you to increase the reference count furthur.
Hope that helps,
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
next prev parent reply other threads:[~2003-02-19 3:45 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-12-26 8:11 [PATCH/RFC] New module refcounting for net_proto_family Max Krasnyansky
2003-01-02 11:43 ` Max Krasnyansky
2003-01-03 8:24 ` David S. Miller
2003-01-20 3:22 ` Max Krasnyansky
2003-01-21 11:03 ` David S. Miller
2003-01-21 19:42 ` Max Krasnyansky
2003-01-21 19:36 ` David S. Miller
2003-02-07 9:48 ` David S. Miller
2003-02-07 23:34 ` Max Krasnyansky
2003-02-08 8:44 ` David S. Miller
2003-02-18 3:46 ` David S. Miller
2003-02-18 18:50 ` Max Krasnyansky
2003-02-18 21:09 ` Jean Tourrilhes
2003-02-19 3:54 ` Rusty Russell [this message]
2003-02-19 7:04 ` David S. Miller
2003-02-19 18:03 ` Max Krasnyansky
2003-02-19 20:31 ` Roman Zippel
2003-02-19 17:45 ` Max Krasnyansky
2003-02-20 1:21 ` Rusty Russell
2003-02-20 17:38 ` Max Krasnyansky
2003-02-21 0:30 ` Rusty Russell
2003-02-21 1:17 ` Max Krasnyansky
2003-02-21 8:45 ` Christoph Hellwig
2003-02-21 17:44 ` Max Krasnyansky
2003-02-24 1:01 ` Rusty Russell
2003-02-24 19:35 ` Max Krasnyansky
2003-02-25 5:02 ` Rusty Russell
2003-02-26 20:21 ` Max Krasnyansky
2003-01-07 9:21 ` David S. Miller
2003-01-09 20:45 ` Max Krasnyansky
2003-01-09 23:53 ` David S. Miller
-- strict thread matches above, loose matches on Subject: below --
2003-02-20 17:52 Max Krasnyansky
2002-12-19 23:08 Jean Tourrilhes
2002-12-19 23:23 ` Max Krasnyansky
2002-12-18 15:25 Max Krasnyansky
2002-12-19 16:05 ` Max Krasnyansky
2002-12-19 19:28 ` Alan Cox
2002-12-19 19:12 ` David S. Miller
2002-12-19 22:17 ` Max Krasnyansky
2002-12-21 6:54 ` David S. Miller
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