Add a drain function for struct sysctl_req, and use it for a variety of

handlers, some of which had to do awkward things to get a large enough
FIXEDLEN buffer.

Note that some sysctl handlers were explicitly outputting a trailing NUL
byte.  This behaviour was preserved, though it should not be necessary.

Reviewed by:	phk

1 files changed, 2 insertions, 7 deletions

diff --git a/sys/vm/vm_reserv.c b/sys/vm/vm_reserv.c
index d9e908f..aa8e80f 100644
--- a/sys/vm/vm_reserv.c
+++ b/sys/vm/vm_reserv.c
@@ -180,12 +180,9 @@ sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS)
 {
 	struct sbuf sbuf;
 	vm_reserv_t rv;
-	char *cbuf;
-	const int cbufsize = (VM_NRESERVLEVEL + 1) * 81;
 	int counter, error, level, unused_pages;
 
-	cbuf = malloc(cbufsize, M_TEMP, M_WAITOK | M_ZERO);
-	sbuf_new(&sbuf, cbuf, cbufsize, SBUF_FIXEDLEN);
+	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
 	sbuf_printf(&sbuf, "\nLEVEL     SIZE  NUMBER\n\n");
 	for (level = -1; level <= VM_NRESERVLEVEL - 2; level++) {
 		counter = 0;
@@ -199,10 +196,8 @@ sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS)
 		sbuf_printf(&sbuf, "%5.5d: %6.6dK, %6.6d\n", level,
 		    unused_pages * (PAGE_SIZE / 1024), counter);
 	}
-	sbuf_finish(&sbuf);
-	error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
+	error = sbuf_finish(&sbuf);
 	sbuf_delete(&sbuf);
-	free(cbuf, M_TEMP);
 	return (error);
 }