swap.c: Refactor getstats() and its usage

Add a return value so we are able to check any errors and actually fail
when there has been a critical error instead of carrying on uselessly.

diff --git a/components/swap.c b/components/swap.c
index c9bb920f69cbbace9618d9b5fcdfd444896e9390..37ee85cb5bf3859da7605ed9384eb2829a36ff12 100644 (file)
--- a/components/swap.c
+++ b/components/swap.c
@@ -135,29 +135,27 @@
        #include <sys/types.h>
        #include <unistd.h>
 
-       static void
+       static int
        getstats(int *total, int *used)
        {
                struct swapent *sep, *fsep;
                int rnswap, nswap, i;
 
-               nswap = swapctl(SWAP_NSWAP, 0, 0);
-               if (nswap < 1) {
+               if ((nswap = swapctl(SWAP_NSWAP, 0, 0)) < 1) {
                        warn("swaptctl 'SWAP_NSWAP':");
+                       return 1;
                }
-
-               fsep = sep = calloc(nswap, sizeof(*sep));
-               if (!sep) {
+               if (!(fsep = sep = calloc(nswap, sizeof(*sep)))) {
                        warn("calloc 'nswap':");
+                       return 1;
                }
-
-               rnswap = swapctl(SWAP_STATS, (void *)sep, nswap);
-               if (rnswap < 0) {
+               if ((rnswap = swapctl(SWAP_STATS, (void *)sep, nswap)) < 0) {
                        warn("swapctl 'SWAP_STATA':");
+                       return 1;
                }
-
                if (nswap != rnswap) {
                        warn("getstats: SWAP_STATS != SWAP_NSWAP");
+                       return 1;
                }
 
                *total = 0;
@@ -169,6 +167,8 @@
                }
 
                free(fsep);
+
+               return 0;
        }
 
        const char *
@@ -176,7 +176,9 @@
        {
                int total, used;
 
-               getstats(&total, &used);
+               if (getstats(&total, &used)) {
+                       return NULL;
+               }
 
                return fmt_human((total - used) * 1024, 1024);
        }
@@ -186,7 +188,9 @@
        {
                int total, used;
 
-               getstats(&total, &used);
+               if (getstats(&total, &used)) {
+                       return NULL;
+               }
 
                if (total == 0) {
                        return NULL;
@@ -200,7 +204,9 @@
        {
                int total, used;
 
-               getstats(&total, &used);
+               if (getstats(&total, &used)) {
+                       return NULL;
+               }
 
                return fmt_human(total * 1024, 1024);
        }
@@ -210,7 +216,9 @@
        {
                int total, used;
 
-               getstats(&total, &used);
+               if (getstats(&total, &used)) {
+                       return NULL;
+               }
 
                return fmt_human(used * 1024, 1024);
        }