4 files changed, 34 insertions, 17 deletions

diff --git a/sys/geom/geom.h b/sys/geom/geom.h
index d00deb3..7f6bf5a 100644
--- a/sys/geom/geom.h
+++ b/sys/geom/geom.h
@@ -336,7 +336,8 @@ extern struct sx topology_lock;
 #endif /* _KERNEL */
 
 /* geom_ctl.c */
-void gctl_set_param(struct gctl_req *req, const char *param, void const *ptr, int len);
+int gctl_set_param(struct gctl_req *req, const char *param, void const *ptr, int len);
+void gctl_set_param_err(struct gctl_req *req, const char *param, void const *ptr, int len);
 void *gctl_get_param(struct gctl_req *req, const char *param, int *len);
 char const *gctl_get_asciiparam(struct gctl_req *req, const char *param);
 void *gctl_get_paraml(struct gctl_req *req, const char *param, int len);
diff --git a/sys/geom/geom_bsd.c b/sys/geom/geom_bsd.c
index b7402cf..7d5b5d1 100644
--- a/sys/geom/geom_bsd.c
+++ b/sys/geom/geom_bsd.c
@@ -635,8 +635,8 @@ g_bsd_config(struct gctl_req *req, struct g_class *mp, char const *verb)
 	gsp = gp->softc;
 	ms = gsp->softc;
 	if (!strcmp(verb, "read mbroffset")) {
-		gctl_set_param(req, "mbroffset",
-		    &ms->mbroffset, sizeof(ms->mbroffset));
+		gctl_set_param_err(req, "mbroffset", &ms->mbroffset,
+		    sizeof(ms->mbroffset));
 		return;
 	} else if (!strcmp(verb, "write label")) {
 		label = gctl_get_paraml(req, "label", LABELSIZE);
diff --git a/sys/geom/geom_ccd.c b/sys/geom/geom_ccd.c
index bfa125d..fb66882 100644
--- a/sys/geom/geom_ccd.c
+++ b/sys/geom/geom_ccd.c
@@ -782,7 +782,7 @@ g_ccd_create(struct gctl_req *req, struct g_class *mp)
 	else
 		sbuf_printf(sb, "concatenated\n");
 	sbuf_finish(sb);
-	gctl_set_param(req, "output", sbuf_data(sb), sbuf_len(sb) + 1);
+	gctl_set_param_err(req, "output", sbuf_data(sb), sbuf_len(sb) + 1);
 	sbuf_delete(sb);
 }
 
@@ -833,7 +833,7 @@ g_ccd_list(struct gctl_req *req, struct g_class *mp)
 		sbuf_printf(sb, "\n");
 	}
 	sbuf_finish(sb);
-	gctl_set_param(req, "output", sbuf_data(sb), sbuf_len(sb) + 1);
+	gctl_set_param_err(req, "output", sbuf_data(sb), sbuf_len(sb) + 1);
 	sbuf_delete(sb);
 }
 
diff --git a/sys/geom/geom_ctl.c b/sys/geom/geom_ctl.c
index 8186bc7..9c183b1 100644
--- a/sys/geom/geom_ctl.c
+++ b/sys/geom/geom_ctl.c
@@ -268,8 +268,9 @@ gctl_dump(struct gctl_req *req)
 	}
 }
 
-void
-gctl_set_param(struct gctl_req *req, const char *param, void const *ptr, int len)
+int
+gctl_set_param(struct gctl_req *req, const char *param, void const *ptr,
+    int len)
 {
 	int i;
 	struct gctl_req_arg *ap;
@@ -278,20 +279,35 @@ gctl_set_param(struct gctl_req *req, const char *param, void const *ptr, int len
 		ap = &req->arg[i];
 		if (strcmp(param, ap->name))
 			continue;
-		if (!(ap->flag & GCTL_PARAM_WR)) {
-			gctl_error(req, "No write access %s argument", param);
-			return;
-		}
+		if (!(ap->flag & GCTL_PARAM_WR))
+			return (EPERM);
+		ap->flag |= GCTL_PARAM_CHANGED;
 		if (ap->len < len) {
-			gctl_error(req, "Wrong length %s argument", param);
-			return;
+			bcopy(ptr, ap->kvalue, ap->len);
+			return (ENOSPC);
 		}
 		bcopy(ptr, ap->kvalue, len);
-		ap->flag |= GCTL_PARAM_CHANGED;
-		return;
+		return (0);
+	}
+	return (EINVAL);
+}
+
+void
+gctl_set_param_err(struct gctl_req *req, const char *param, void const *ptr,
+    int len)
+{
+
+	switch (gctl_set_param(req, param, ptr, len)) {
+	case EPERM:
+		gctl_error(req, "No write access %s argument", param);
+		break;
+	case ENOSPC:
+		gctl_error(req, "Wrong length %s argument", param);
+		break;
+	case EINVAL:
+		gctl_error(req, "Missing %s argument", param);
+		break;
 	}
-	gctl_error(req, "Missing %s argument", param);
-	return;
 }
 
 void *