Merge pull request #3934 from avagin:feature/fuse

PiperOrigin-RevId: 332122081

1 files changed, 105 insertions, 0 deletions

diff --git a/pkg/sentry/fsimpl/fuse/directory.go b/pkg/sentry/fsimpl/fuse/directory.go
new file mode 100644
index 000000000..ee77dbaa3
--- /dev/null
+++ b/pkg/sentry/fsimpl/fuse/directory.go
@@ -0,0 +1,105 @@
+// 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 fuse
+
+import (
+	"sync/atomic"
+
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/syserror"
+	"gvisor.dev/gvisor/pkg/usermem"
+)
+
+type directoryFD struct {
+	fileDescription
+}
+
+// Allocate implements directoryFD.Allocate.
+func (*directoryFD) Allocate(ctx context.Context, mode, offset, length uint64) error {
+	return syserror.EISDIR
+}
+
+// PRead implements FileDescriptionImpl.PRead.
+func (*directoryFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
+	return 0, syserror.EISDIR
+}
+
+// Read implements FileDescriptionImpl.Read.
+func (*directoryFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
+	return 0, syserror.EISDIR
+}
+
+// PWrite implements FileDescriptionImpl.PWrite.
+func (*directoryFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
+	return 0, syserror.EISDIR
+}
+
+// Write implements FileDescriptionImpl.Write.
+func (*directoryFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
+	return 0, syserror.EISDIR
+}
+
+// IterDirents implements FileDescriptionImpl.IterDirents.
+func (dir *directoryFD) IterDirents(ctx context.Context, callback vfs.IterDirentsCallback) error {
+	fusefs := dir.inode().fs
+	task, creds := kernel.TaskFromContext(ctx), auth.CredentialsFromContext(ctx)
+
+	in := linux.FUSEReadIn{
+		Fh:     dir.Fh,
+		Offset: uint64(atomic.LoadInt64(&dir.off)),
+		Size:   linux.FUSE_PAGE_SIZE,
+		Flags:  dir.statusFlags(),
+	}
+
+	// TODO(gVisor.dev/issue/3404): Support FUSE_READDIRPLUS.
+	req, err := fusefs.conn.NewRequest(creds, uint32(task.ThreadID()), dir.inode().nodeID, linux.FUSE_READDIR, &in)
+	if err != nil {
+		return err
+	}
+
+	res, err := fusefs.conn.Call(task, req)
+	if err != nil {
+		return err
+	}
+	if err := res.Error(); err != nil {
+		return err
+	}
+
+	var out linux.FUSEDirents
+	if err := res.UnmarshalPayload(&out); err != nil {
+		return err
+	}
+
+	for _, fuseDirent := range out.Dirents {
+		nextOff := int64(fuseDirent.Meta.Off)
+		dirent := vfs.Dirent{
+			Name:    fuseDirent.Name,
+			Type:    uint8(fuseDirent.Meta.Type),
+			Ino:     fuseDirent.Meta.Ino,
+			NextOff: nextOff,
+		}
+
+		if err := callback.Handle(dirent); err != nil {
+			return err
+		}
+		atomic.StoreInt64(&dir.off, nextOff)
+	}
+
+	return nil
+}