[PATCH 2/3] NFS: flexfilelayout: Mark err as __maybe_unused in ff_layout_io_track_ds_error

[Peng Fan (OSS)]

From: Peng Fan <peng.fan@xxxxxxx>

Fix the following compiler warning when building with W=1:

  flexfilelayout.c: In function 'ff_layout_io_track_ds_error':
  flexfilelayout.c:1503:6:
  error: variable 'err' set but not used [-Werror=unused-but-set-variable]
   1503 |  int err;
        |      ^~~

Variable 'err' is assigned the return value of ff_layout_track_ds_error()
but is only used in the dprintk() debug statement at the end of the
function. When debug output is disabled, the variable appears unused to
the compiler.

Mark it as __maybe_unused to indicate this is intentional.

Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---
 fs/nfs/flexfilelayout/flexfilelayout.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index cd175204807600ff4e33ff769e03ef7ac700a6dc..1d8099337652a1cdbcaf58d394a6e981e8e7e413 100644
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -1500,7 +1500,7 @@ 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;
 
 	if (status == 0) {
 		switch (error) {

-- 
2.37.1