Add VFS2 support for /proc/filesystems.

Updates #1195

PiperOrigin-RevId: 287269106

6 files changed, 34 insertions, 20 deletions

diff --git a/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go b/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go
index 2f46d2d13..a56b03711 100644
--- a/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go
+++ b/pkg/sentry/fsimpl/ext/benchmark/benchmark_test.go
@@ -50,7 +50,9 @@ func setUp(b *testing.B, imagePath string) (context.Context, *vfs.VirtualFilesys
 
 	// Create VFS.
 	vfsObj := vfs.New()
-	vfsObj.MustRegisterFilesystemType("extfs", ext.FilesystemType{})
+	vfsObj.MustRegisterFilesystemType("extfs", ext.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+	})
 	mntns, err := vfsObj.NewMountNamespace(ctx, creds, imagePath, "extfs", &vfs.GetFilesystemOptions{InternalData: int(f.Fd())})
 	if err != nil {
 		f.Close()
diff --git a/pkg/sentry/fsimpl/ext/ext_test.go b/pkg/sentry/fsimpl/ext/ext_test.go
index 5d6c999bd..6c14a1e2d 100644
--- a/pkg/sentry/fsimpl/ext/ext_test.go
+++ b/pkg/sentry/fsimpl/ext/ext_test.go
@@ -66,7 +66,9 @@ func setUp(t *testing.T, imagePath string) (context.Context, *vfs.VirtualFilesys
 
 	// Create VFS.
 	vfsObj := vfs.New()
-	vfsObj.MustRegisterFilesystemType("extfs", FilesystemType{})
+	vfsObj.MustRegisterFilesystemType("extfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+	})
 	mntns, err := vfsObj.NewMountNamespace(ctx, creds, localImagePath, "extfs", &vfs.GetFilesystemOptions{InternalData: int(f.Fd())})
 	if err != nil {
 		f.Close()
diff --git a/pkg/sentry/fsimpl/kernfs/kernfs_test.go b/pkg/sentry/fsimpl/kernfs/kernfs_test.go
index 3db12caa0..4b6b95f5f 100644
--- a/pkg/sentry/fsimpl/kernfs/kernfs_test.go
+++ b/pkg/sentry/fsimpl/kernfs/kernfs_test.go
@@ -59,7 +59,9 @@ func newTestSystem(t *testing.T, rootFn RootDentryFn) *TestSystem {
 	ctx := contexttest.Context(t)
 	creds := auth.CredentialsFromContext(ctx)
 	v := vfs.New()
-	v.MustRegisterFilesystemType("testfs", &fsType{rootFn: rootFn})
+	v.MustRegisterFilesystemType("testfs", &fsType{rootFn: rootFn}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+	})
 	mns, err := v.NewMountNamespace(ctx, creds, "", "testfs", &vfs.GetFilesystemOptions{})
 	if err != nil {
 		t.Fatalf("Failed to create testfs root mount: %v", err)
diff --git a/pkg/sentry/fsimpl/memfs/benchmark_test.go b/pkg/sentry/fsimpl/memfs/benchmark_test.go
index 6e987af88..a27876a4e 100644
--- a/pkg/sentry/fsimpl/memfs/benchmark_test.go
+++ b/pkg/sentry/fsimpl/memfs/benchmark_test.go
@@ -176,7 +176,9 @@ func BenchmarkVFS2MemfsStat(b *testing.B) {
 
 			// Create VFS.
 			vfsObj := vfs.New()
-			vfsObj.MustRegisterFilesystemType("memfs", memfs.FilesystemType{})
+			vfsObj.MustRegisterFilesystemType("memfs", memfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+				AllowUserMount: true,
+			})
 			mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "memfs", &vfs.GetFilesystemOptions{})
 			if err != nil {
 				b.Fatalf("failed to create tmpfs root mount: %v", err)
@@ -365,7 +367,9 @@ func BenchmarkVFS2MemfsMountStat(b *testing.B) {
 
 			// Create VFS.
 			vfsObj := vfs.New()
-			vfsObj.MustRegisterFilesystemType("memfs", memfs.FilesystemType{})
+			vfsObj.MustRegisterFilesystemType("memfs", memfs.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+				AllowUserMount: true,
+			})
 			mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "memfs", &vfs.GetFilesystemOptions{})
 			if err != nil {
 				b.Fatalf("failed to create tmpfs root mount: %v", err)
diff --git a/pkg/sentry/fsimpl/memfs/pipe_test.go b/pkg/sentry/fsimpl/memfs/pipe_test.go
index be917aeee..807c1af7a 100644
--- a/pkg/sentry/fsimpl/memfs/pipe_test.go
+++ b/pkg/sentry/fsimpl/memfs/pipe_test.go
@@ -152,7 +152,9 @@ func setup(t *testing.T) (context.Context, *auth.Credentials, *vfs.VirtualFilesy
 
 	// Create VFS.
 	vfsObj := vfs.New()
-	vfsObj.MustRegisterFilesystemType("memfs", FilesystemType{})
+	vfsObj.MustRegisterFilesystemType("memfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+	})
 	mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "memfs", &vfs.GetFilesystemOptions{})
 	if err != nil {
 		t.Fatalf("failed to create tmpfs root mount: %v", err)
diff --git a/pkg/sentry/fsimpl/proc/tasks_test.go b/pkg/sentry/fsimpl/proc/tasks_test.go
index 48201d75a..2560fcef9 100644
--- a/pkg/sentry/fsimpl/proc/tasks_test.go
+++ b/pkg/sentry/fsimpl/proc/tasks_test.go
@@ -56,25 +56,25 @@ func checkDots(dirs []vfs.Dirent) ([]vfs.Dirent, error) {
 
 func checkTasksStaticFiles(gots []vfs.Dirent) ([]vfs.Dirent, error) {
 	wants := map[string]vfs.Dirent{
-		"loadavg":     vfs.Dirent{Type: linux.DT_REG},
-		"meminfo":     vfs.Dirent{Type: linux.DT_REG},
-		"mounts":      vfs.Dirent{Type: linux.DT_LNK},
-		"self":        vfs.Dirent{Type: linux.DT_LNK},
-		"stat":        vfs.Dirent{Type: linux.DT_REG},
-		"thread-self": vfs.Dirent{Type: linux.DT_LNK},
-		"version":     vfs.Dirent{Type: linux.DT_REG},
+		"loadavg":     {Type: linux.DT_REG},
+		"meminfo":     {Type: linux.DT_REG},
+		"mounts":      {Type: linux.DT_LNK},
+		"self":        {Type: linux.DT_LNK},
+		"stat":        {Type: linux.DT_REG},
+		"thread-self": {Type: linux.DT_LNK},
+		"version":     {Type: linux.DT_REG},
 	}
 	return checkFiles(gots, wants)
 }
 
 func checkTaskStaticFiles(gots []vfs.Dirent) ([]vfs.Dirent, error) {
 	wants := map[string]vfs.Dirent{
-		"io":     vfs.Dirent{Type: linux.DT_REG},
-		"maps":   vfs.Dirent{Type: linux.DT_REG},
-		"smaps":  vfs.Dirent{Type: linux.DT_REG},
-		"stat":   vfs.Dirent{Type: linux.DT_REG},
-		"statm":  vfs.Dirent{Type: linux.DT_REG},
-		"status": vfs.Dirent{Type: linux.DT_REG},
+		"io":     {Type: linux.DT_REG},
+		"maps":   {Type: linux.DT_REG},
+		"smaps":  {Type: linux.DT_REG},
+		"stat":   {Type: linux.DT_REG},
+		"statm":  {Type: linux.DT_REG},
+		"status": {Type: linux.DT_REG},
 	}
 	return checkFiles(gots, wants)
 }
@@ -114,7 +114,9 @@ func setup() (context.Context, *vfs.VirtualFilesystem, vfs.VirtualDentry, error)
 	creds := auth.CredentialsFromContext(ctx)
 
 	vfsObj := vfs.New()
-	vfsObj.MustRegisterFilesystemType("procfs", &procFSType{})
+	vfsObj.MustRegisterFilesystemType("procfs", &procFSType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+	})
 	mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "procfs", &vfs.GetFilesystemOptions{})
 	if err != nil {
 		return nil, nil, vfs.VirtualDentry{}, fmt.Errorf("NewMountNamespace(): %v", err)