feat: vfs - add dynamic filesystem mounts and safe unmount lifecycle

kernel/src/Fs/FsProbe.cpp

@@ -17,6 +17,15 @@ namespace Fs::FsProbe {
     static bool g_mounted[Drivers::Storage::Gpt::MaxPartitions] = {};
     static int g_driveForPart[Drivers::Storage::Gpt::MaxPartitions] = {};
 
+    // A successful probe returns an owned mount. Registration transfers that
+    // ownership to the VFS; if registration loses a drive-slot race, release
+    // the mount here so its driver, instance, and page allocations do not leak.
+    static void DiscardUnregisteredDriver(Vfs::FsDriver* driver) {
+        if (driver != nullptr && driver->Unmount != nullptr) {
+            driver->Unmount(driver->ctx);
+        }
+    }
+
     void Register(ProbeFn fn) {
         if (g_probeCount < MaxProbes && fn) {
             g_probes[g_probeCount++] = fn;
@@ -60,6 +69,7 @@ namespace Fs::FsProbe {
                 return 1;
             }
 
+            DiscardUnregisteredDriver(driver);
             return -1;
         }
 
@@ -135,6 +145,7 @@ namespace Fs::FsProbe {
                         << partIndex << " as drive " << driveNum;
                     return 0;
                 }
+                DiscardUnregisteredDriver(driver);
                 return -1;
             }
         }