Skip parent directory creation in mount (#4310)

A POSIX filesystem does not implicitly create parent directories when
they do not exist. Directories must be explicitly created and
permissions be set.

This also fixes a bug where asynchronous operations would create a
file in the filer before the parent directory was created. If the
file was a symlink or another special type of file the directory
would inherit that type and become unusable in the mounted FS.

weed/mount/weedfs_dir_mkrm.go

@@ -3,14 +3,16 @@ package mount
 import (
 	"context"
 	"fmt"
-	"github.com/hanwen/go-fuse/v2/fuse"
-	"github.com/seaweedfs/seaweedfs/weed/filer"
-	"github.com/seaweedfs/seaweedfs/weed/glog"
-	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 	"os"
 	"strings"
 	"syscall"
 	"time"
+
+	"github.com/hanwen/go-fuse/v2/fuse"
+
+	"github.com/seaweedfs/seaweedfs/weed/filer"
+	"github.com/seaweedfs/seaweedfs/weed/glog"
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 )
 
 /** Create a directory
@@ -57,6 +59,7 @@ func (wfs *WFS) Mkdir(cancel <-chan struct{}, in *fuse.MkdirIn, name string, out
 			Directory:                string(dirFullPath),
 			Entry:                    newEntry,
 			Signatures:               []int32{wfs.signature},
+			SkipCheckParentDirectory: true,
 		}
 
 		glog.V(1).Infof("mkdir: %v", request)

weed/mount/weedfs_link.go

@@ -2,12 +2,14 @@ package mount
 
 import (
 	"context"
+	"syscall"
+	"time"
+
 	"github.com/hanwen/go-fuse/v2/fuse"
+
 	"github.com/seaweedfs/seaweedfs/weed/filer"
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
-	"syscall"
-	"time"
 )
 
 /*
@@ -73,6 +75,7 @@ func (wfs *WFS) Link(cancel <-chan struct{}, in *fuse.LinkIn, name string, out *
 			HardLinkCounter: oldEntry.HardLinkCounter,
 		},
 		Signatures:               []int32{wfs.signature},
+		SkipCheckParentDirectory: true,
 	}
 
 	// apply changes to the filer, and also apply to local metaCache

weed/mount/weedfs_symlink.go

@@ -3,13 +3,15 @@ package mount
 import (
 	"context"
 	"fmt"
+	"os"
+	"syscall"
+	"time"
+
 	"github.com/hanwen/go-fuse/v2/fuse"
+
 	"github.com/seaweedfs/seaweedfs/weed/filer"
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
-	"os"
-	"syscall"
-	"time"
 )
 
 /** Create a symbolic link */
@@ -43,6 +45,7 @@ func (wfs *WFS) Symlink(cancel <-chan struct{}, header *fuse.InHeader, target st
 			},
 		},
 		Signatures:               []int32{wfs.signature},
+		SkipCheckParentDirectory: true,
 	}
 
 	err := wfs.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {