Message-ID: <143423e3-03b2-8b5d-f897-33126edd2594@redhat.com>
Date:   Wed, 10 Nov 2021 14:16:49 -0500
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Subject: Re: [PATCH nfs-utils] mount: don't bind a socket needlessly.
Content-Language: en-US
To:     NeilBrown <neilb@suse.de>
Cc:     linux-nfs@vger.kernel.org
References: <163582252847.13683.7467712657489228784@noble.neil.brown.name>
From:   Steve Dickson <steved@redhat.com>
In-Reply-To: <163582252847.13683.7467712657489228784@noble.neil.brown.name>
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Hello,

On 11/1/21 23:08, NeilBrown wrote:
> 
> When clnt_ping() calls get_socket(), get_socket() will create a socket,
> call bind() to choose an unused local port, and then connect to the
> given address.
> 
> The "bind()" call is unnecessary and problematic.
> It is unnecessary as the "connect()" call will bind the socket as
> required.
> It is problematic as it requires a completely unused port number, rather
> than just a port number which isn't currently in use for connecting to
> the given remote address.
> If all local ports (net.ipv4.ip_local_port_range) are in use, the bind()
> will fail.  However the connect() call will only fail if all those port
> are in use for connecting to the same address.
> 
> So remove the unnecessary bind() call.
> 
> Signed-off-by: NeilBrown <neilb@suse.de>
Committed... (tag: nfs-utils-2-5-5-rc4)

steved.

> ---
>   utils/mount/network.c | 4 ----
>   1 file changed, 4 deletions(-)
> 
> diff --git a/utils/mount/network.c b/utils/mount/network.c
> index e803dbbe5a2c..35261171a615 100644
> --- a/utils/mount/network.c
> +++ b/utils/mount/network.c
> @@ -429,10 +429,6 @@ static int get_socket(struct sockaddr_in *saddr, unsigned int p_prot,
>   	if (resvp) {
>   		if (bindresvport(so, &laddr) < 0)
>   			goto err_bindresvport;
> -	} else {
> -		cc = bind(so, SAFE_SOCKADDR(&laddr), namelen);
> -		if (cc < 0)
> -			goto err_bind;
>   	}
>   	if (type == SOCK_STREAM || (conn && type == SOCK_DGRAM)) {
>   		cc = connect_to(so, SAFE_SOCKADDR(saddr), namelen,
>