nodefs: support Access

nodefs/api.go

@@ -102,6 +102,7 @@ type Operations interface {
 
 	StatFs(ctx context.Context, out *fuse.StatfsOut) fuse.Status
 
+	Access(ctx context.Context, mask uint32) fuse.Status
 	// File locking
 	GetLk(ctx context.Context, f FileHandle, owner uint64, lk *fuse.FileLock, flags uint32, out *fuse.FileLock) (status fuse.Status)
 	SetLk(ctx context.Context, f FileHandle, owner uint64, lk *fuse.FileLock, flags uint32) (status fuse.Status)

nodefs/bridge.go

@@ -408,7 +408,8 @@ func (b *rawBridge) Readlink(cancel <-chan struct{}, header *fuse.InHeader) (out
 }
 
 func (b *rawBridge) Access(cancel <-chan struct{}, input *fuse.AccessIn) (status fuse.Status) {
-	return fuse.ENOSYS
+	n, _ := b.inode(input.NodeId, 0)
+	return n.node.Access(&fuse.Context{Caller: input.Caller, Cancel: cancel}, input.Mask)
 }
 
 // Extended attributes.

nodefs/default.go

@@ -227,6 +227,10 @@ func (n *DefaultOperations) RemoveXAttr(ctx context.Context, attr string) fuse.S
 	return fuse.ENOATTR
 }
 
+func (n *DefaultOperations) Access(ctx context.Context, mask uint32) fuse.Status {
+	return fuse.ENOSYS
+}
+
 func (n *DefaultOperations) ListXAttr(ctx context.Context, dest []byte) (uint32, fuse.Status) {
 	return 0, fuse.OK
 }

nodefs/loopback.go

@@ -6,17 +6,15 @@ package nodefs
 
 import (
 	"context"
-	"log"
 	"os"
 	"path/filepath"
 	"sync"
 	"syscall"
 
 	"github.com/hanwen/go-fuse/fuse"
+	"github.com/hanwen/go-fuse/internal"
 )
 
-var _ = log.Printf
-
 type loopbackRoot struct {
 	loopbackNode
 
@@ -339,3 +337,21 @@ func (n *loopbackNode) ListXAttr(ctx context.Context, dest []byte) (uint32, fuse
 	sz, err := syscall.Listxattr(n.path(), dest)
 	return uint32(sz), fuse.ToStatus(err)
 }
+
+func (n *loopbackNode) Access(ctx context.Context, mask uint32) fuse.Status {
+	caller, ok := fuse.FromContext(ctx)
+	if !ok {
+		return fuse.EACCES
+	}
+
+	var st syscall.Stat_t
+	if err := syscall.Stat(n.path(), &st); err != nil {
+		return fuse.ToStatus(err)
+	}
+
+	if !internal.HasAccess(caller.Uid, caller.Gid, st.Uid, st.Gid, st.Mode, mask) {
+		return fuse.EACCES
+	}
+	return fuse.OK
+
+}