[PATCH 5.15.y 09/18] sunrpc: don't change ->sv_stats if it doesn't exist

[cel@kernel.org]

From: Josef Bacik <josef@toxicpanda.com>

[ Upstream commit ab42f4d9a26f1723dcfd6c93fcf768032b2bb5e7 ]

We check for the existence of ->sv_stats elsewhere except in the core
processing code.  It appears that only nfsd actual exports these values
anywhere, everybody else just has a write only copy of sv_stats in their
svc_program.  Add a check for ->sv_stats before every adjustment to
allow us to eliminate the stats struct from all the users who don't
report the stats.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
[ cel: adjusted to apply to v5.15.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/svc.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 8d5897ed2816..447f515d445b 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1357,7 +1357,8 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 		goto err_bad_proc;
 
 	/* Syntactic check complete */
-	serv->sv_stats->rpccnt++;
+	if (serv->sv_stats)
+		serv->sv_stats->rpccnt++;
 	trace_svc_process(rqstp, progp->pg_name);
 
 	/* Build the reply header. */
@@ -1423,7 +1424,8 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 	goto close_xprt;
 
 err_bad_rpc:
-	serv->sv_stats->rpcbadfmt++;
+	if (serv->sv_stats)
+		serv->sv_stats->rpcbadfmt++;
 	svc_putnl(resv, 1);	/* REJECT */
 	svc_putnl(resv, 0);	/* RPC_MISMATCH */
 	svc_putnl(resv, 2);	/* Only RPCv2 supported */
@@ -1436,7 +1438,8 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 err_bad_auth:
 	dprintk("svc: authentication failed (%d)\n",
 		be32_to_cpu(rqstp->rq_auth_stat));
-	serv->sv_stats->rpcbadauth++;
+	if (serv->sv_stats)
+		serv->sv_stats->rpcbadauth++;
 	/* Restore write pointer to location of accept status: */
 	xdr_ressize_check(rqstp, reply_statp);
 	svc_putnl(resv, 1);	/* REJECT */
@@ -1446,7 +1449,8 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 
 err_bad_prog:
 	dprintk("svc: unknown program %d\n", prog);
-	serv->sv_stats->rpcbadfmt++;
+	if (serv->sv_stats)
+		serv->sv_stats->rpcbadfmt++;
 	svc_putnl(resv, RPC_PROG_UNAVAIL);
 	goto sendit;
 
@@ -1454,7 +1458,8 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 	svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
 		       rqstp->rq_vers, rqstp->rq_prog, progp->pg_name);
 
-	serv->sv_stats->rpcbadfmt++;
+	if (serv->sv_stats)
+		serv->sv_stats->rpcbadfmt++;
 	svc_putnl(resv, RPC_PROG_MISMATCH);
 	svc_putnl(resv, process.mismatch.lovers);
 	svc_putnl(resv, process.mismatch.hivers);
@@ -1463,7 +1468,8 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 err_bad_proc:
 	svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_proc);
 
-	serv->sv_stats->rpcbadfmt++;
+	if (serv->sv_stats)
+		serv->sv_stats->rpcbadfmt++;
 	svc_putnl(resv, RPC_PROC_UNAVAIL);
 	goto sendit;
 
@@ -1472,7 +1478,8 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 
 	rpc_stat = rpc_garbage_args;
 err_bad:
-	serv->sv_stats->rpcbadfmt++;
+	if (serv->sv_stats)
+		serv->sv_stats->rpcbadfmt++;
 	svc_putnl(resv, ntohl(rpc_stat));
 	goto sendit;
 }
@@ -1513,7 +1520,8 @@ svc_process(struct svc_rqst *rqstp)
 	if (dir != 0) {
 		/* direction != CALL */
 		svc_printk(rqstp, "bad direction %d, dropping request\n", dir);
-		serv->sv_stats->rpcbadfmt++;
+		if (serv->sv_stats)
+			serv->sv_stats->rpcbadfmt++;
 		goto out_drop;
 	}
 
-- 
2.45.2