Moved FUSE device under the fuse directory

6 files changed, 44 insertions, 68 deletions

diff --git a/pkg/sentry/devices/miscdev/miscdev.go b/pkg/sentry/devices/miscdev/miscdev.go
deleted file mode 100644
index 500d92ed9..000000000
--- a/pkg/sentry/devices/miscdev/miscdev.go
+++ /dev/null
@@ -1,54 +0,0 @@
-// Copyright 2020 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 miscdev implements "misc" character devices, as implemented in Linux
-// by drivers/char/misc.c and fs/fuse/dev.c.
-package miscdev
-
-import (
-	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/context"
-	"gvisor.dev/gvisor/pkg/sentry/fsimpl/devtmpfs"
-	"gvisor.dev/gvisor/pkg/sentry/vfs"
-)
-
-// miscDevMajor is the major device number for devices defined in this package.
-const miscDevMajor = linux.MISC_MAJOR
-
-// Register registers all devices implemented by this package in vfsObj.
-func Register(vfsObj *vfs.VirtualFilesystem) error {
-	for minor, dev := range map[uint32]vfs.Device{
-		fuseDevMinor: fuseDevice{},
-	} {
-		if err := vfsObj.RegisterDevice(vfs.CharDevice, miscDevMajor, minor, dev, &vfs.RegisterDeviceOptions{
-			GroupName: "misc",
-		}); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// CreateDevtmpfsFiles creates device special files in dev representing all
-// devices implemented by this package.
-func CreateDevtmpfsFiles(ctx context.Context, dev *devtmpfs.Accessor) error {
-	for minor, name := range map[uint32]string{
-		fuseDevMinor: "fuse",
-	} {
-		if err := dev.CreateDeviceFile(ctx, name, vfs.CharDevice, miscDevMajor, minor, 0666 /* mode */); err != nil {
-			return err
-		}
-	}
-	return nil
-}
diff --git a/pkg/sentry/devices/miscdev/BUILD b/pkg/sentry/fsimpl/fuse/BUILD
index aaa76c5d2..41567967d 100644
--- a/pkg/sentry/devices/miscdev/BUILD
+++ b/pkg/sentry/fsimpl/fuse/BUILD
@@ -3,10 +3,9 @@ load("//tools:defs.bzl", "go_library")
 licenses(["notice"])
 
 go_library(
-    name = "miscdev",
+    name = "fuse",
     srcs = [
-        "fuse.go",
-        "miscdev.go",
+        "dev.go",
     ],
     visibility = ["//pkg/sentry:internal"],
     deps = [
diff --git a/pkg/sentry/devices/miscdev/fuse.go b/pkg/sentry/fsimpl/fuse/dev.go
index d0a963191..f6a67d005 100644
--- a/pkg/sentry/devices/miscdev/fuse.go
+++ b/pkg/sentry/fsimpl/fuse/dev.go
@@ -12,10 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package miscdev
+package fuse
 
 import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/sentry/fsimpl/devtmpfs"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -28,7 +30,7 @@ type fuseDevice struct{}
 
 // Open implements vfs.Device.Open.
 func (fuseDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
-	var fd FUSEDeviceFile
+	var fd DeviceFD
 	if err := fd.vfsfd.Init(&fd, opts.Flags, mnt, vfsd, &vfs.FileDescriptionOptions{
 		UseDentryMetadata: true,
 	}); err != nil {
@@ -37,8 +39,8 @@ func (fuseDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, op
 	return &fd.vfsfd, nil
 }
 
-// FUSEDeviceFile implements vfs.FileDescriptionImpl for /dev/fuse.
-type FUSEDeviceFile struct {
+// DeviceFD implements vfs.FileDescriptionImpl for /dev/fuse.
+type DeviceFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
@@ -50,29 +52,49 @@ type FUSEDeviceFile struct {
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
-func (fd *FUSEDeviceFile) Release() {}
+func (fd *DeviceFD) Release() {}
 
 // PRead implements vfs.FileDescriptionImpl.PRead.
-func (fd *FUSEDeviceFile) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
+func (fd *DeviceFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
 	return 0, syserror.ENOSYS
 }
 
 // Read implements vfs.FileDescriptionImpl.Read.
-func (fd *FUSEDeviceFile) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
+func (fd *DeviceFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
 	return 0, syserror.ENOSYS
 }
 
 // PWrite implements vfs.FileDescriptionImpl.PWrite.
-func (fd *FUSEDeviceFile) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
+func (fd *DeviceFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
 	return 0, syserror.ENOSYS
 }
 
 // Write implements vfs.FileDescriptionImpl.Write.
-func (fd *FUSEDeviceFile) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
+func (fd *DeviceFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
 	return 0, syserror.ENOSYS
 }
 
 // Seek implements vfs.FileDescriptionImpl.Seek.
-func (fd *FUSEDeviceFile) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
+func (fd *DeviceFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
 	return 0, syserror.ENOSYS
 }
+
+// Register registers the FUSE device with vfsObj.
+func Register(vfsObj *vfs.VirtualFilesystem) error {
+	if err := vfsObj.RegisterDevice(vfs.CharDevice, linux.MISC_MAJOR, fuseDevMinor, fuseDevice{}, &vfs.RegisterDeviceOptions{
+		GroupName: "misc",
+	}); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// CreateDevtmpfsFile creates a device special file in devtmpfs.
+func CreateDevtmpfsFile(ctx context.Context, dev *devtmpfs.Accessor) error {
+	if err := dev.CreateDeviceFile(ctx, "fuse", vfs.CharDevice, linux.MISC_MAJOR, fuseDevMinor, 0666 /* mode */); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/runsc/boot/BUILD b/runsc/boot/BUILD
index 45d7f7d09..aad2a41de 100644
--- a/runsc/boot/BUILD
+++ b/runsc/boot/BUILD
@@ -55,6 +55,7 @@ go_library(
         "//pkg/sentry/fs/user",
         "//pkg/sentry/fsimpl/devpts",
         "//pkg/sentry/fsimpl/devtmpfs",
+        "//pkg/sentry/fsimpl/fuse",
         "//pkg/sentry/fsimpl/gofer",
         "//pkg/sentry/fsimpl/host",
         "//pkg/sentry/fsimpl/overlay",
diff --git a/runsc/boot/vfs.go b/runsc/boot/vfs.go
index 9ba5e9cd9..0f5ad1e05 100644
--- a/runsc/boot/vfs.go
+++ b/runsc/boot/vfs.go
@@ -31,6 +31,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/user"
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/devpts"
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/devtmpfs"
+	"gvisor.dev/gvisor/pkg/sentry/fsimpl/fuse"
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/gofer"
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/overlay"
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/proc"
@@ -79,6 +80,9 @@ func registerFilesystems(ctx context.Context, vfsObj *vfs.VirtualFilesystem, cre
 	}
 	if err := ttydev.Register(vfsObj); err != nil {
 		return fmt.Errorf("registering ttydev: %w", err)
+
+	if err := fuse.Register(vfsObj); err != nil {
+		return fmt.Errorf("registering /dev/fuse: %w", err)
 	}
 	if err := tundev.Register(vfsObj); err != nil {
 		return fmt.Errorf("registering tundev: %v", err)
@@ -101,6 +105,9 @@ func registerFilesystems(ctx context.Context, vfsObj *vfs.VirtualFilesystem, cre
 	if err := tundev.CreateDevtmpfsFiles(ctx, a); err != nil {
 		return fmt.Errorf("creating tundev devtmpfs files: %v", err)
 	}
+	if err := fuse.CreateDevtmpfsFile(ctx, a); err != nil {
+		return fmt.Errorf("creating devtmpfs fuse device file: %w", err)
+	}
 	return nil
 }
 
diff --git a/test/syscalls/linux/dev.cc b/test/syscalls/linux/dev.cc
index 82b115981..6be173c14 100644
--- a/test/syscalls/linux/dev.cc
+++ b/test/syscalls/linux/dev.cc
@@ -165,7 +165,8 @@ TEST(DevTest, WriteDevFuse) {
 }
 
 TEST(DevTest, TTYExists) {
-  SKIP_IF(!IsRunningWithVFS1());
+  // Run test if running on VFS1 or on Linux.
+  SKIP_IF(!IsRunningWithVFS1() && IsRunningOnGvisor());
 
   struct stat statbuf = {};
   ASSERT_THAT(stat("/dev/tty", &statbuf), SyscallSucceeds());