From cf2eb2d83bda5f0db3cc76f07d083bfcf039fc2a Mon Sep 17 00:00:00 2001
From: Filipe Azevedo <pasnox@gmail.com>
Date: Wed, 14 Dec 2022 22:14:20 +0100
Subject: [PATCH] mount: introduce symlink support #2975

---
 cmd/mount/dir.go  | 28 ++++++++++++++++++++++++----
 cmd/mount/file.go | 10 +++++++++-
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/cmd/mount/dir.go b/cmd/mount/dir.go
index 1252177b9..e32c9c941 100644
--- a/cmd/mount/dir.go
+++ b/cmd/mount/dir.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path"
 	"syscall"
 	"time"
 
@@ -33,7 +34,7 @@ func (d *Dir) Attr(ctx context.Context, a *fuse.Attr) (err error) {
 	a.Valid = time.Duration(d.fsys.opt.AttrTimeout)
 	a.Gid = d.VFS().Opt.GID
 	a.Uid = d.VFS().Opt.UID
-	a.Mode = os.ModeDir | os.FileMode(d.VFS().Opt.DirPerms)
+	a.Mode = d.Mode()
 	modTime := d.ModTime()
 	a.Atime = modTime
 	a.Mtime = modTime
@@ -140,11 +141,13 @@ var _ fusefs.NodeCreater = (*Dir)(nil)
 // Create makes a new file
 func (d *Dir) Create(ctx context.Context, req *fuse.CreateRequest, resp *fuse.CreateResponse) (node fusefs.Node, handle fusefs.Handle, err error) {
 	defer log.Trace(d, "name=%q", req.Name)("node=%v, handle=%v, err=%v", &node, &handle, &err)
-	file, err := d.Dir.Create(req.Name, int(req.Flags))
+	// translate the fuse flags to os flags
+	osFlags := int(req.Flags) | os.O_CREATE
+	file, err := d.Dir.Create(req.Name, osFlags)
 	if err != nil {
 		return nil, nil, translateError(err)
 	}
-	fh, err := file.Open(int(req.Flags) | os.O_CREATE)
+	fh, err := file.Open(osFlags)
 	if err != nil {
 		return nil, nil, translateError(err)
 	}
@@ -200,7 +203,6 @@ func (d *Dir) Rename(ctx context.Context, req *fuse.RenameRequest, newDir fusefs
 	if !ok {
 		return fmt.Errorf("unknown Dir type %T", newDir)
 	}
-
 	err = d.Dir.Rename(req.OldName, req.NewName, destDir.Dir)
 	if err != nil {
 		return translateError(err)
@@ -239,6 +241,24 @@ func (d *Dir) Link(ctx context.Context, req *fuse.LinkRequest, old fusefs.Node)
 	return nil, syscall.ENOSYS
 }
 
+var _ fusefs.NodeSymlinker = (*Dir)(nil)
+
+// Symlink create a symbolic link.
+func (d *Dir) Symlink(ctx context.Context, req *fuse.SymlinkRequest) (node fusefs.Node, err error) {
+	defer log.Trace(d, "newname=%v, target=%v", req.NewName, req.Target)("node=%v, err=%v", &node, &err)
+
+	newName := path.Join(d.Path(), req.NewName)
+	target := req.Target
+
+	n, err := d.VFS().CreateSymlink(target, newName)
+	if err != nil {
+		return nil, err
+	}
+
+	node = &File{n.(*vfs.File), d.fsys}
+	return node, nil
+}
+
 // Check interface satisfied
 var _ fusefs.NodeMknoder = (*Dir)(nil)
 
diff --git a/cmd/mount/file.go b/cmd/mount/file.go
index bc9883443..713ae3a9e 100644
--- a/cmd/mount/file.go
+++ b/cmd/mount/file.go
@@ -32,7 +32,7 @@ func (f *File) Attr(ctx context.Context, a *fuse.Attr) (err error) {
 	Blocks := (Size + 511) / 512
 	a.Gid = f.VFS().Opt.GID
 	a.Uid = f.VFS().Opt.UID
-	a.Mode = os.FileMode(f.VFS().Opt.FilePerms)
+	a.Mode = f.File.Mode() &^ os.ModeAppend
 	a.Size = Size
 	a.Atime = modTime
 	a.Mtime = modTime
@@ -129,3 +129,11 @@ func (f *File) Removexattr(ctx context.Context, req *fuse.RemovexattrRequest) er
 }
 
 var _ fusefs.NodeRemovexattrer = (*File)(nil)
+
+var _ fusefs.NodeReadlinker = (*File)(nil)
+
+// Readlink read symbolic link target.
+func (f *File) Readlink(ctx context.Context, req *fuse.ReadlinkRequest) (ret string, err error) {
+	defer log.Trace(f, "")("ret=%v, err=%v", &ret, &err)
+	return f.VFS().Readlink(f.Path())
+}