return swap listing in the disk route

src/system.js

@@ -2,6 +2,7 @@
 
 exports = module.exports = {
     getDisks,
+    getSwaps,
     checkDiskSpace,
     getMemory,
     getMemoryAllocation,
@@ -35,6 +36,25 @@ async function du(file) {
     return parseInt(stdoutResult.trim(), 10);
 }
 
+async function getSwaps() {
+    const stdout = safe.child_process.execSync('swapon --noheadings --raw --bytes --show=type,size,used,name', { encoding: 'utf8' });
+    if (!stdout) return {};
+
+    const swaps = {};
+    for (const line of stdout.trim().split('\n')) {
+        const parts = line.split(' ', 4);
+        const name = parts[3];
+        swaps[name] = {
+            name: parts[3],
+            type: parts[0], // partition or file
+            size: parseInt(parts[1]),
+            used: parseInt(parts[2]),
+        };
+    }
+
+    return swaps;
+}
+
 async function getDisks() {
     let [dfError, dfEntries] = await safe(df.disks());
     if (dfError) throw new BoxError(BoxError.FS_ERROR, `Error running df: ${dfError.message}`);
@@ -120,25 +140,23 @@ async function checkDiskSpace() {
     await notifications.alert(notifications.ALERT_DISK_SPACE, 'Server is running out of disk space', markdownMessage);
 }
 
-function getSwapSize() {
-    const stdout = safe.child_process.execSync('swapon --noheadings --raw --bytes --show=SIZE', { encoding: 'utf8' });
-    const swap = !stdout ? 0 : stdout.trim().split('\n').map(x => parseInt(x, 10) || 0).reduce((acc, cur) => acc + cur);
-
-    return swap;
+async function getSwapSize() {
+    const swaps = await getSwaps();
+    return Object.keys(swaps).map(n => swaps[n].size).reduce((acc, cur) => acc + cur);
 }
 
 async function getMemory() {
     return {
         memory: os.totalmem(),
-        swap: getSwapSize()
+        swap: await getSwapSize()
     };
 }
 
-function getMemoryAllocation(limit) {
+async function getMemoryAllocation(limit) {
     let ratio = parseFloat(safe.fs.readFileSync(paths.SWAP_RATIO_FILE, 'utf8'), 10);
 
     if (!ratio) {
-        const pc = os.totalmem() / (os.totalmem() + getSwapSize());
+        const pc = os.totalmem() / (os.totalmem() + await getSwapSize());
         ratio = Math.round(pc * 10) / 10; // a simple ratio
     }