Thread (6 messages) 6 messages, 2 authors, 2026-02-25

Re: [PATCH v3 1/2] nfs: fix unused variable warning when CONFIG_SUNRPC_DEBUG is disabled

From: Andrew Lunn <andrew@lunn.ch>
Date: 2026-02-24 17:54:42
Also in: linux-nfs, lkml

On Wed, Feb 25, 2026 at 12:54:34AM +0800, Sean Chang wrote:
quoted hunk ↗ jump to hunk
When CONFIG_SUNRPC_DEBUG is disabled, the dprintk() macro expands to
an empty do-while loop. This causes variables used solely within
dprintk() calls to appear unused to the compiler, triggering
-Wunused-variable warnings.

Fix this by adding __maybe_unused to the affected variables. This
ensures the code builds cleanly across different configurations,
including RISC-V, ARM, and ARM64 allmodconfig, as verified in the
mailing list discussion.

Signed-off-by: Sean Chang <redacted>
---
 fs/nfs/flexfilelayout/flexfilelayout.c    | 2 +-
 fs/nfs/flexfilelayout/flexfilelayoutdev.c | 3 ++-
 fs/nfs/nfs4proc.c                         | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index 9056f05a67dc..de9e8bad6af2 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -1502,7 +1502,7 @@ static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
 {
 	struct nfs4_ff_layout_mirror *mirror;
 	u32 status = *op_status;
-	int err;
+	int err __maybe_unused;
Sorry, but this is ugly. There must be a better way to fix this.

Maybe look at no_printk().

https://elixir.bootlin.com/linux/v6.19.3/source/drivers/video/fbdev/core/fbmon.c#L50

#ifdef DEBUG
#define DPRINTK(fmt, args...) printk(fmt,## args)
#else
#define DPRINTK(fmt, args...) no_printk(fmt, ##args)
#endif

    Andrew

---
pw-bot: cr
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help