Change gctl_set_param() to return an error instead of setting an

error on the request.  Add a wrapper, gctl_set_param_err(), that
sets the error on the request from the error returned by
gctl_set_param() and update current callers of gctl_set_param()
to call gctl_set_param_err() instead.
This makes gctl_set_param() much more usable in situations where
the caller knows better what to do with certain (apparent) error
conditions and setting an error on the request is not one of the
things that need to be done.

1 files changed, 28 insertions, 12 deletions

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 *