On Mon, Oct 16, 2023 at 3:09 PM Geert Uytterhoeven
<geert+renesas@xxxxxxxxx> 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>
> --- a/include/linux/sunrpc/debug.h
> +++ b/include/linux/sunrpc/debug.h
> @@ -67,9 +67,9 @@ do { \
> # define RPC_IFDEBUG(x) x
> #else
> # define ifdebug(fac) if (0)
> -# define dfprintk(fac, fmt, ...) do {} while (0)
> -# define dfprintk_cont(fac, fmt, ...) do {} while (0)
> -# define dfprintk_rcu(fac, fmt, ...) do {} while (0)
> +# define dfprintk(fac, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
> +# define dfprintk_cont(fac, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
> +# define dfprintk_rcu(fac, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
> # define RPC_IFDEBUG(x)
> #endif
I discovered a new build issue related to the use of RPC_IFDEBUG()
in fs/nfsd/nfsfh.c. So there will be a v4...
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
