Add shared mount hints to VFS2

Container restart test is disabled for VFS2 for now.

Updates #1487

PiperOrigin-RevId: 320296401

3 files changed, 6 insertions, 7 deletions

diff --git a/pkg/sentry/fsimpl/testutil/kernel.go b/pkg/sentry/fsimpl/testutil/kernel.go
index ecc81e6bf..e743e8114 100644
--- a/pkg/sentry/fsimpl/testutil/kernel.go
+++ b/pkg/sentry/fsimpl/testutil/kernel.go
@@ -62,6 +62,7 @@ func Boot() (*kernel.Kernel, error) {
 		return nil, fmt.Errorf("creating platform: %v", err)
 	}
 
+	kernel.VFS2Enabled = true
 	k := &kernel.Kernel{
 		Platform: plat,
 	}
@@ -103,11 +104,6 @@ func Boot() (*kernel.Kernel, error) {
 		return nil, fmt.Errorf("initializing kernel: %v", err)
 	}
 
-	kernel.VFS2Enabled = true
-
-	if err := k.VFS().Init(); err != nil {
-		return nil, fmt.Errorf("VFS init: %v", err)
-	}
 	k.VFS().MustRegisterFilesystemType(tmpfs.Name, &tmpfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
 		AllowUserMount: true,
 		AllowUserList:  true,
diff --git a/pkg/sentry/loader/loader.go b/pkg/sentry/loader/loader.go
index e65ec4771..986c7fb4d 100644
--- a/pkg/sentry/loader/loader.go
+++ b/pkg/sentry/loader/loader.go
@@ -221,14 +221,14 @@ func Load(ctx context.Context, args LoadArgs, extraAuxv []arch.AuxEntry, vdso *V
 	// Load the executable itself.
 	loaded, ac, file, newArgv, err := loadExecutable(ctx, args)
 	if err != nil {
-		return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Failed to load %s: %v", args.Filename, err), syserr.FromError(err).ToLinux())
+		return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("failed to load %s: %v", args.Filename, err), syserr.FromError(err).ToLinux())
 	}
 	defer file.DecRef()
 
 	// Load the VDSO.
 	vdsoAddr, err := loadVDSO(ctx, args.MemoryManager, vdso, loaded)
 	if err != nil {
-		return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("Error loading VDSO: %v", err), syserr.FromError(err).ToLinux())
+		return 0, nil, "", syserr.NewDynamic(fmt.Sprintf("error loading VDSO: %v", err), syserr.FromError(err).ToLinux())
 	}
 
 	// Setup the heap. brk starts at the next page after the end of the
diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go
index 58c7ad778..522e27475 100644
--- a/pkg/sentry/vfs/vfs.go
+++ b/pkg/sentry/vfs/vfs.go
@@ -123,6 +123,9 @@ type VirtualFilesystem struct {
 
 // Init initializes a new VirtualFilesystem with no mounts or FilesystemTypes.
 func (vfs *VirtualFilesystem) Init() error {
+	if vfs.mountpoints != nil {
+		panic("VFS already initialized")
+	}
 	vfs.mountpoints = make(map[*Dentry]map[*Mount]struct{})
 	vfs.devices = make(map[devTuple]*registeredDevice)
 	vfs.anonBlockDevMinorNext = 1