LU-11894 lnet: check for asymmetrical route messages

[fs/lustre-release.git] / lnet / lnet / api-ni.c

diff --git a/lnet/lnet/api-ni.c b/lnet/lnet/api-ni.c
index 55d2779..186be3d 100644 (file)
--- a/lnet/lnet/api-ni.c
+++ b/lnet/lnet/api-ni.c
@@ -160,6 +160,25 @@ module_param_call(lnet_peer_discovery_disabled, discovery_set, param_get_int,
 MODULE_PARM_DESC(lnet_peer_discovery_disabled,
                "Set to 1 to disable peer discovery on this node.");
 
+unsigned int lnet_drop_asym_route;
+static int drop_asym_route_set(const char *val, cfs_kernel_param_arg_t *kp);
+
+static struct kernel_param_ops param_ops_drop_asym_route = {
+       .set = drop_asym_route_set,
+       .get = param_get_int,
+};
+
+#define param_check_drop_asym_route(name, p)   \
+       __param_check(name, p, int)
+#ifdef HAVE_KERNEL_PARAM_OPS
+module_param(lnet_drop_asym_route, drop_asym_route, 0644);
+#else
+module_param_call(lnet_drop_asym_route, drop_asym_route_set, param_get_int,
+                 &param_ops_drop_asym_route, 0644);
+#endif
+MODULE_PARM_DESC(lnet_drop_asym_route,
+                "Set to 1 to drop asymmetrical route messages.");
+
 unsigned lnet_transaction_timeout = 50;
 static int transaction_to_set(const char *val, cfs_kernel_param_arg_t *kp);
 #ifdef HAVE_KERNEL_PARAM_OPS
@@ -339,6 +358,38 @@ discovery_set(const char *val, cfs_kernel_param_arg_t *kp)
 }
 
 static int
+drop_asym_route_set(const char *val, cfs_kernel_param_arg_t *kp)
+{
+       int rc;
+       unsigned int *drop_asym_route = (unsigned int *)kp->arg;
+       unsigned long value;
+
+       rc = kstrtoul(val, 0, &value);
+       if (rc) {
+               CERROR("Invalid module parameter value for "
+                      "'lnet_drop_asym_route'\n");
+               return rc;
+       }
+
+       /*
+        * The purpose of locking the api_mutex here is to ensure that
+        * the correct value ends up stored properly.
+        */
+       mutex_lock(&the_lnet.ln_api_mutex);
+
+       if (value == *drop_asym_route) {
+               mutex_unlock(&the_lnet.ln_api_mutex);
+               return 0;
+       }
+
+       *drop_asym_route = value;
+
+       mutex_unlock(&the_lnet.ln_api_mutex);
+
+       return 0;
+}
+
+static int
 transaction_to_set(const char *val, cfs_kernel_param_arg_t *kp)
 {
        int rc;