Received-SPF: pass (google.com: domain of linux-nfs+bounces-2300-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Message-ID: <8f246658-2131-48b0-90fe-404cb8f8097b@redhat.com>
Date: Fri, 15 Mar 2024 09:11:22 -0400
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH nfs-utils] start-statd: use flock -x instead of -e for
 busybox compatibility
To: Ahmad Fatoum <a.fatoum@pengutronix.de>, NeilBrown <neilb@suse.de>
Cc: linux-nfs@vger.kernel.org, kernel@pengutronix.de
References: <20240228185644.2743036-1-a.fatoum@pengutronix.de>
Content-Language: en-US
From: Steve Dickson <steved@redhat.com>
In-Reply-To: <20240228185644.2743036-1-a.fatoum@pengutronix.de>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit


On 2/28/24 1:56 PM, Ahmad Fatoum wrote:
> busybox flock(1) only supports -x and not -e. util-linux flock(1)
> treats both -e and -x the same, documents them both in its man page,
> but lists only -x in its help output.
> 
> Referring to util-linux git, it seems both options were added between
> util-linux-2.13-pre1 and util-linux-2.13-pre2 back in 2006, so there
> should be no harm in switching over to flock -x to avoid confusing
> error output when attempting to mount a NFS on a busybox system:
> 
>    $ mount -t nfs 192.168.2.13:/home/afa/nfsroot/imx8mn-evk /mnt
>    flock: invalid option -- 'e'
>    BusyBox v1.36.0 () multi-call binary.
> 
>    Usage: flock [-sxun] FD | { FILE [-c] PROG ARGS }
> 
>    [Un]lock file descriptor, or lock FILE, run PROG
> 
>            -s      Shared lock
>            -x      Exclusive lock (default)
>            -u      Unlock FD
>            -n      Fail rather than wait
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Committed... (tag  nfs-utils-2-7-1-rc5)

I like that fact the lock is explicitly
set... takes out the guess work.

steved.
> ---
>   utils/statd/start-statd | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/utils/statd/start-statd b/utils/statd/start-statd
> index b11a7d91a7f6..67a2f4ad8e0e 100755
> --- a/utils/statd/start-statd
> +++ b/utils/statd/start-statd
> @@ -8,7 +8,7 @@ PATH="/sbin:/usr/sbin:/bin:/usr/bin"
>   
>   # Use flock to serialize the running of this script
>   exec 9> /run/rpc.statd.lock
> -flock -e 9
> +flock -x 9
>   
>   if [ -s /run/rpc.statd.pid ] &&
>          [ "1$(cat /run/rpc.statd.pid)" -gt 1 ] &&