linux-kernel - Re: [PATCH] net/tls: Remove redundant initialization of mp

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Date:   Sat, 1 Jan 2022 14:57:16 +1100
From:   Dave Chinner <david@...morbit.com>
To:     Jiapeng Chong <jiapeng.chong@...ux.alibaba.com>
Cc:     djwong@...nel.org, linux-xfs@...r.kernel.org,
        linux-kernel@...r.kernel.org, Abaci Robot <abaci@...ux.alibaba.com>
Subject: Re: [PATCH] net/tls: Remove redundant initialization of mp

On Fri, Dec 31, 2021 at 08:23:52PM +0800, Jiapeng Chong wrote:
> mp is being initialized to log->l_mp but this is never read
> as record is overwritten later on. Remove the redundant
> initialization.

The compiler is not smart enough to just elide the second "mp =
log->l_mp;" assignment?


> Cleans up the following clang-analyzer warning:
> 
> fs/xfs/xfs_log_recover.c:3543:20: warning: Value stored to 'mp' during
> its initialization is never read [clang-analyzer-deadcode.DeadStores].
> 
> Reported-by: Abaci Robot <abaci@...ux.alibaba.com>
> Signed-off-by: Jiapeng Chong <jiapeng.chong@...ux.alibaba.com>
> ---
>  fs/xfs/xfs_log_recover.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
> index 8ecb9a8567b7..9142efbdc670 100644
> --- a/fs/xfs/xfs_log_recover.c
> +++ b/fs/xfs/xfs_log_recover.c
> @@ -3540,7 +3540,7 @@ STATIC void
>  xlog_recover_check_summary(
>  	struct xlog		*log)
>  {
> -	struct xfs_mount	*mp = log->l_mp;
> +	struct xfs_mount	*mp;
>  	struct xfs_perag	*pag;
>  	struct xfs_buf		*agfbp;
>  	struct xfs_buf		*agibp;

You removed the wrong initialisation line. Leave this one here and
remove the standalone one.

Cheers,

Dave.
-- 
Dave Chinner
david@...morbit.com