Symbolic link support

[jetwhiz]

Environment

• Windows version: Windows 7
• Processor architecture: x86
• Dokany version: v1.0.0-RC4
• Library type (Dokany/FUSE): FUSE

Check List

• I checked my issue doesn't exist yet
• [?] My issue is valid with mirror default sample and not specific to my user-mode driver implementation
• I can always reproduce the issue with the provided description below.
• I have updated Dokany to the latest version (https://github.com/dokan-dev/dokany/releases) and have reboot my computer after.

Description

Is symbolic link creation support implemented for Dokany FUSE?

I looked through the fusemain.cpp source code but didn't notice where ops_.symlink is being called, and when I run a mklink request on the command line for encfs4win, my symlink function is never triggered.

From what I can tell (here), mklink is triggering create_file, which doesn't appear to trigger ops_.symlink anywhere.

Logs

mklink Z:\b.txt Z:\x\a.txt

###Create 0002
CreateFile: \b.txt
        DesiredAccess: SYNCHRONIZE|DELETE|FILE_WRITE_ATTRIBUTES
        ShareAccess: 0x0
        Disposition: FILE_CREATE (2)
        Attributes: 128 (0x80)
        Options: 2097248 (0x200060)
CreateFile status = 0 - lastError = 0
###GetFileInfo 0002
GetFileInfo: : \b.txt
        result =  0
        FileStandardInformation
        DispatchQueryInformation result =  0
###Create 0003
CreateFile: \
        DesiredAccess: SYNCHRONIZE|FILE_READ_DATA
        ShareAccess: FILE_SHARE_DELETE|FILE_SHARE_WRITE|FILE_SHARE_READ
        Disposition: FILE_OPEN (1)
        Attributes: 144 (0x90)
        Options: 16417 (0x4021)
CreateFile status = 0 - lastError = 0
###FindFiles 0003
FindFiles: \
index from 0
FileMatch? : . (b.txt,0,0)
FileMatch? : .. (b.txt,0,0)
FileMatch? : b.txt (b.txt,0,0)
  =>return single entry
index to 1
###Cleanup 0003
Cleanup: \

###Close 0003
Close: \

###GetFileInfo 0002
GetFileInfo: : \b.txt
        result =  0
        FileBasicInformation
        DispatchQueryInformation result =  0
###GetFileInfo 0002
GetFileInfo: : \b.txt
        result =  0
        FileStandardInformation
        DispatchQueryInformation result =  0
###GetFileInfo 0002
GetFileInfo: : \b.txt
        result =  0
        FileInternalInformation
        DispatchQueryInformation result =  0
###SetFileInfo 0002  13
GetFileInfo: : \b.txt
DeleteFile: \b.txt
  dispositionInfo->DeleteFile = 1
        DispatchSetInformation result =  0
###Cleanup 0002
Cleanup: \b.txt

###Close 0002
Close: \b.txt

[kyanha]

symlinks in Windows are implemented by the filesystem code as reparse points, which require Fsctl implementation. Dokany doesn't yet support Fsctl dispatch, and as a result Dokany doesn't yet support reparse points.

Here's the documentation I've been able to find about this, on the Windows side.

####Fsctls required

• FSCTL_GET_REPARSE_POINT
• FSCTL_DELETE_REPARSE_POINT
• FSCTL_SET_REPARSE_POINT

####Structures

• _REPARSE_DATA_BUFFER
• _REPARSE_DATA_BUFFER_EX

####Microsoft Open Standards

• MS-FSCC
• Specific section of MS-FSCC for IO_REPARSE_TAG_SYMLINK