3 files changed, 68 insertions, 0 deletions
diff --git a/pkg/sentry/fs/anon/anon.go b/pkg/sentry/fs/anon/anon.go
new file mode 100644
index 000000000..a6ea8b9e7
--- /dev/null
+++ b/pkg/sentry/fs/anon/anon.go
@@ -0,0 +1,42 @@
+// Copyright 2018 The gVisor Authors.
+//
+// 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 anon implements an anonymous inode, useful for implementing
+// inodes for pseudo filesystems.
+package anon
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil"
+	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+)
+
+// NewInode constructs an anonymous Inode that is not associated
+// with any real filesystem. Some types depend on completely pseudo
+// "anon" inodes (eventfds, epollfds, etc).
+func NewInode(ctx context.Context) *fs.Inode {
+	iops := &fsutil.SimpleFileInode{
+		InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, fs.RootOwner, fs.FilePermissions{
+			User: fs.PermMask{Read: true, Write: true},
+		}, linux.ANON_INODE_FS_MAGIC),
+	}
+	return fs.NewInode(iops, fs.NewPseudoMountSource(), fs.StableAttr{
+		Type:      fs.Anonymous,
+		DeviceID:  PseudoDevice.DeviceID(),
+		InodeID:   PseudoDevice.NextIno(),
+		BlockSize: usermem.PageSize,
+	})
+}
diff --git a/pkg/sentry/fs/anon/anon_state_autogen.go b/pkg/sentry/fs/anon/anon_state_autogen.go
new file mode 100755
index 000000000..fcb914212
--- /dev/null
+++ b/pkg/sentry/fs/anon/anon_state_autogen.go
@@ -0,0 +1,4 @@
+// automatically generated by stateify.
+
+package anon
+
diff --git a/pkg/sentry/fs/anon/device.go b/pkg/sentry/fs/anon/device.go
new file mode 100644
index 000000000..5927bd11e
--- /dev/null
+++ b/pkg/sentry/fs/anon/device.go
@@ -0,0 +1,22 @@
+// Copyright 2018 The gVisor Authors.
+//
+// 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 anon
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/sentry/device"
+)
+
+// PseudoDevice is the device on which all anonymous inodes reside.
+var PseudoDevice = device.NewAnonDevice()