Check in gVisor.

PiperOrigin-RevId: 194583126
Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463

1 files changed, 73 insertions, 0 deletions

diff --git a/pkg/sentry/fs/tmpfs/file_test.go b/pkg/sentry/fs/tmpfs/file_test.go
new file mode 100644
index 000000000..f064eb1ac
--- /dev/null
+++ b/pkg/sentry/fs/tmpfs/file_test.go
@@ -0,0 +1,73 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tmpfs
+
+import (
+	"bytes"
+	"testing"
+
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context/contexttest"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/platform"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usage"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+)
+
+func newFileInode(ctx context.Context) *fs.Inode {
+	m := fs.NewCachingMountSource(&Filesystem{}, fs.MountSourceFlags{})
+	iops := NewInMemoryFile(ctx, usage.Tmpfs, fs.WithCurrentTime(ctx, fs.UnstableAttr{}), platform.FromContext(ctx))
+	return fs.NewInode(iops, m, fs.StableAttr{
+		DeviceID:  tmpfsDevice.DeviceID(),
+		InodeID:   tmpfsDevice.NextIno(),
+		BlockSize: usermem.PageSize,
+		Type:      fs.RegularFile,
+	})
+}
+
+func newFile(ctx context.Context) *fs.File {
+	inode := newFileInode(ctx)
+	f, _ := inode.GetFile(ctx, fs.NewDirent(inode, "stub"), fs.FileFlags{Read: true, Write: true})
+	return f
+}
+
+// Allocate once, write twice.
+func TestGrow(t *testing.T) {
+	ctx := contexttest.Context(t)
+	f := newFile(ctx)
+	defer f.DecRef()
+
+	abuf := bytes.Repeat([]byte{'a'}, 68)
+	n, err := f.Pwritev(ctx, usermem.BytesIOSequence(abuf), 0)
+	if n != int64(len(abuf)) || err != nil {
+		t.Fatalf("DeprecatedPwritev got (%d, %v) want (%d, nil)", n, err, len(abuf))
+	}
+
+	bbuf := bytes.Repeat([]byte{'b'}, 856)
+	n, err = f.Pwritev(ctx, usermem.BytesIOSequence(bbuf), 68)
+	if n != int64(len(bbuf)) || err != nil {
+		t.Fatalf("DeprecatedPwritev got (%d, %v) want (%d, nil)", n, err, len(bbuf))
+	}
+
+	rbuf := make([]byte, len(abuf)+len(bbuf))
+	n, err = f.Preadv(ctx, usermem.BytesIOSequence(rbuf), 0)
+	if n != int64(len(rbuf)) || err != nil {
+		t.Fatalf("DeprecatedPreadv got (%d, %v) want (%d, nil)", n, err, len(rbuf))
+	}
+
+	if want := append(abuf, bbuf...); !bytes.Equal(rbuf, want) {
+		t.Fatalf("Read %v, want %v", rbuf, want)
+	}
+}