fix: show disk usage for the mount being browsed (#1347)

plugins/file-manager/src/frontend/FileManagerSidebar.tsx

@@ -27,7 +27,7 @@ import {
   removeFolderShortcut,
 } from "./api/file-manager-data-api";
 import { listSSHFiles } from "./api/ssh-file-operations-api";
-import type { DiskFilesystem } from "./disk-info";
+import { mountForPath, type DiskFilesystem } from "./disk-info";
 import { toast } from "sonner";
 import FolderTree from "./components/FolderTree";
 import {
@@ -702,11 +702,13 @@ export function FileManagerSidebar({
   // ─── Render ───────────────────────────────────────────────────────────────────
 
   const storageFilesystems = diskInfo?.filesystems ?? [];
-  const activeStorageMount = selectedMount ?? diskInfo?.mount ?? null;
+  const pathFs = mountForPath(storageFilesystems, currentPath);
+  const activeStorageMount =
+    selectedMount ?? pathFs?.mount ?? diskInfo?.mount ?? null;
   const selectedFs =
     selectedMount !== null
       ? (storageFilesystems.find((fs) => fs.mount === selectedMount) ?? null)
-      : null;
+      : pathFs;
 
   const storage =
     selectedFs && selectedFs.percent !== null

plugins/file-manager/src/frontend/disk-info.ts

@@ -20,3 +20,19 @@ export interface HostDiskInfo {
   mount: string | null;
   filesystems?: DiskFilesystem[];
 }
+
+/** The filesystem the path lives on: the longest mount point that holds it. */
+export function mountForPath(
+  filesystems: DiskFilesystem[],
+  path: string | null | undefined,
+): DiskFilesystem | null {
+  if (!path) return null;
+  let best: DiskFilesystem | null = null;
+  for (const fs of filesystems) {
+    const mount = fs.mount.replace(/\/+$/, "") || "/";
+    const inside =
+      mount === "/" || path === mount || path.startsWith(`${mount}/`);
+    if (inside && (!best || mount.length > best.mount.length)) best = fs;
+  }
+  return best;
+}