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From: Kuniyuki Iwashima <kuniyu@amazon•com>
To: <ebiederm@xmission•com>
Cc: <davem@davemloft•net>, <edumazet@google•com>, <kuba@kernel•org>,
	<kuni1840@gmail•com>, <kuniyu@amazon•com>,
	<netdev@vger•kernel.org>, <pabeni@redhat•com>
Subject: Re: [PATCH v3 net 5/6] mpls: Handle error of rtnl_register_module().
Date: Mon, 7 Oct 2024 08:42:10 -0700	[thread overview]
Message-ID: <20241007154210.22366-1-kuniyu@amazon.com> (raw)
In-Reply-To: <87h69ohsgj.fsf@email.froward.int.ebiederm.org>

From: "Eric W. Biederman" <ebiederm@xmission•com>
Date: Mon, 07 Oct 2024 09:56:44 -0500
> Kuniyuki Iwashima <kuniyu@amazon•com> writes:
> 
> > Since introduced, mpls_init() has been ignoring the returned
> > value of rtnl_register_module(), which could fail.
> 
> As I recall that was deliberate.  The module continues to work if the
> rtnetlink handlers don't operate, just some functionality is lost.

It's ok if it wasn't a module.  rtnl_register() logs an error message
in syslog, but rtnl_register_module() doesn't.  That's why this series
only changes some rtnl_register_module() calls.


> 
> I don't strongly care either way, but I want to point out that bailing
> out due to a memory allocation failure actually makes the module
> initialization more brittle.
> 
> > Let's handle the errors by rtnl_register_many().
> 
> Can you describe what the benefit is from completely giving up in the
> face of a memory allocation failure versus having as much of the module
> function as possible?

What if the memory pressure happend to be relaxed soon after the module
was loaded incompletely ?

Silent failure is much worse to me.

rtnl_get_link() will return NULL and users will see -EOPNOTSUPP even
though the module was loaded "successfully".

  reply	other threads:[~2024-10-07 15:42 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-07 12:44 [PATCH v3 net 0/6] rtnetlink: Handle error of rtnl_register_module() Kuniyuki Iwashima
2024-10-07 12:44 ` [PATCH v3 net 1/6] rtnetlink: Add bulk registration helpers for rtnetlink message handlers Kuniyuki Iwashima
2024-10-07 12:44 ` [PATCH v3 net 2/6] vxlan: Handle error of rtnl_register_module() Kuniyuki Iwashima
2024-10-07 12:44 ` [PATCH v3 net 3/6] bridge: " Kuniyuki Iwashima
2024-10-07 12:44 ` [PATCH v3 net 4/6] mctp: " Kuniyuki Iwashima
2024-10-07 12:44 ` [PATCH v3 net 5/6] mpls: " Kuniyuki Iwashima
2024-10-07 14:56   ` Eric W. Biederman
2024-10-07 15:42     ` Kuniyuki Iwashima [this message]
2024-10-07 16:28       ` Eric W. Biederman
2024-10-07 18:21         ` Kuniyuki Iwashima
2024-10-07 22:18           ` Eric W. Biederman
2024-10-07 23:48             ` Kuniyuki Iwashima
2024-10-07 12:44 ` [PATCH v3 net 6/6] phonet: " Kuniyuki Iwashima

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