[PATCH] nfsd: Move strlen declaration in nfsd4_encode_components_esc()

[Nathan Chancellor <nathan@kernel.org>]

There is an error building nfs4xdr.c with CONFIG_SUNRPC_DEBUG_TRACE=y
and CONFIG_FORTIFY_SOURCE=n due to the local variable strlen conflicting
with the function strlen():

  In file included from include/linux/cpumask.h:11,
                   from arch/x86/include/asm/paravirt.h:21,
                   from arch/x86/include/asm/irqflags.h:102,
                   from include/linux/irqflags.h:18,
                   from include/linux/spinlock.h:59,
                   from include/linux/mmzone.h:8,
                   from include/linux/gfp.h:7,
                   from include/linux/slab.h:16,
                   from fs/nfsd/nfs4xdr.c:37:
  fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_components_esc':
  include/linux/kernel.h:321:46: error: called object 'strlen' is not a function or function pointer
    321 |                 __trace_puts(_THIS_IP_, str, strlen(str));              \
        |                                              ^~~~~~
  include/linux/kernel.h:265:17: note: in expansion of macro 'trace_puts'
    265 |                 trace_puts(fmt);                        \
        |                 ^~~~~~~~~~
  include/linux/sunrpc/debug.h:34:41: note: in expansion of macro 'trace_printk'
     34 | #  define __sunrpc_printk(fmt, ...)     trace_printk(fmt, ##__VA_ARGS__)
        |                                         ^~~~~~~~~~~~
  include/linux/sunrpc/debug.h:42:17: note: in expansion of macro '__sunrpc_printk'
     42 |                 __sunrpc_printk(fmt, ##__VA_ARGS__);                    \
        |                 ^~~~~~~~~~~~~~~
  include/linux/sunrpc/debug.h:25:9: note: in expansion of macro 'dfprintk'
     25 |         dfprintk(FACILITY, fmt, ##__VA_ARGS__)
        |         ^~~~~~~~
  fs/nfsd/nfs4xdr.c:2646:9: note: in expansion of macro 'dprintk'
   2646 |         dprintk("nfsd4_encode_components(%s)\n", components);
        |         ^~~~~~~
  fs/nfsd/nfs4xdr.c:2643:13: note: declared here
   2643 |         int strlen, count=0;
        |             ^~~~~~

Move the declaration of strlen into the while loop (as that is the only
place where it is used), which is after the call to dprintk, to clear up
the error.

Fixes: ec7d8e68ef0e ("sunrpc: add a Kconfig option to redirect dfprintk() output to trace buffer")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
This solution may be too subtle but given that dprintk() seems to be on
its way out, maybe it is fine. An alternative would be a rename such as
str_len but there is some symmetry with pathlen so I opted for this one
up front.
---
 fs/nfsd/nfs4xdr.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index ea91bad4eee2..580bfa8011c7 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2640,7 +2640,7 @@ static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
 	__be32 *p;
 	__be32 pathlen;
 	int pathlen_offset;
-	int strlen, count=0;
+	int count=0;
 	char *str, *end, *next;
 
 	dprintk("nfsd4_encode_components(%s)\n", components);
@@ -2654,6 +2654,7 @@ static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
 	end = str = components;
 	while (*end) {
 		bool found_esc = false;
+		int strlen;
 
 		/* try to parse as esc_start, ..., esc_end, sep */
 		if (*str == esc_enter) {

---
base-commit: 3fadfaec904dffab02ebf63dd9c2ae8fa15c6d32
change-id: 20250925-nfsd-fix-trace-printk-strlen-error-2a24413eb186

Best regards,
--  
Nathan Chancellor <nathan@kernel.org>