Re: [PATCH -next v3 2/2] sunrpc: Use no_printk() in dfprintk*() dummies

[Benjamin Coddington]

On 16 Oct 2023, at 9:09, Geert Uytterhoeven wrote:

> When building NFS with W=1 and CONFIG_WERROR=y, but
> CONFIG_SUNRPC_DEBUG=n:
>
>     fs/nfs/nfs4proc.c: In function ‘nfs4_proc_create_session’:
>     fs/nfs/nfs4proc.c:9276:19: error: variable ‘ptr’ set but not used [-Werror=unused-but-set-variable]
>      9276 |         unsigned *ptr;
> 	  |                   ^~~
>       CC      fs/nfs/callback.o
>     fs/nfs/callback.c: In function ‘nfs41_callback_svc’:
>     fs/nfs/callback.c:98:13: error: variable ‘error’ set but not used [-Werror=unused-but-set-variable]
>        98 |         int error;
> 	  |             ^~~~~
>       CC      fs/nfs/flexfilelayout/flexfilelayout.o
>     fs/nfs/flexfilelayout/flexfilelayout.c: In function ‘ff_layout_io_track_ds_error’:
>     fs/nfs/flexfilelayout/flexfilelayout.c:1230:13: error: variable ‘err’ set but not used [-Werror=unused-but-set-variable]
>      1230 |         int err;
> 	  |             ^~~
>       CC      fs/nfs/flexfilelayout/flexfilelayoutdev.o
>     fs/nfs/flexfilelayout/flexfilelayoutdev.c: In function ‘nfs4_ff_alloc_deviceid_node’:
>     fs/nfs/flexfilelayout/flexfilelayoutdev.c:55:16: error: variable ‘ret’ set but not used [-Werror=unused-but-set-variable]
>        55 |         int i, ret = -ENOMEM;
> 	  |                ^~~
>
> All these are due to variables that are set unconditionally, but are
> used only when debugging is enabled.
>
> Fix this by changing the dfprintk*() dummy macros from empty loops to
> calls to the no_printk() helper.  This informs the compiler that the
> passed debug parameters are actually used, and enables format specifier
> checking as a bonus.
>
> This requires removing the protection by CONFIG_SUNRPC_DEBUG of the
> declaration of nlmdbg_cookie2a() in fs/lockd/svclock.c, as its reference
> is now visible to the compiler, but optimized away.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Acked-by: Jeff Layton <jlayton@xxxxxxxxxx>

Reviewed-by: Benjamin Coddington <bcodding@xxxxxxxxxx>

Ben