os.lstat doesn't properly set st_reparse_tag for junction on a remote NetApp share

Bug report

\\192.168.10.198\vol1\sub is a junction on NetApp share, but in Python 3.10.4 st_reparse_tag is set to 0:

>>> path = "\\\\192.168.10.198\\vol1\\sub"
>>> os.lstat(path).st_reparse_tag
0

>fsutil reparsepoint query \\192.168.10.198\vol1\sub
Reparse Tag Value : 0xa0000003
Tag value: Microsoft
Tag value: Name Surrogate
Tag value: Mount Point
Substitue Name offset: 0
Substitue Name length: 98
Print Name offset:     100
Print Name Length:     98
Substitute Name:       \??\Volume{804BBB02-0000-0000-6270-052200000040}\
Print Name:            \??\Volume{804BBB02-0000-0000-6270-052200000040}\

I checked in the Python code that:

• os.lstat uses GetFileInformationByHandleEx call with FileAttributeTagInfo to get the value of the reparse tag
• DeviceIoControl with FSCTL_GET_REPARSE_POINT, which is also used in Python source code, works fine
• the problem doesn't affect regular remote Windows shares (NTFS filesystem)

Your environment

• CPython versions tested on: 3.10.4
• Operating system and architecture: Windows 2019, NetApp share

首先检查 os.lstat 背后的 Windows 实现，尤其是使用 FileAttributeTagInfo 调用 GetFileInformationByHandleEx 的部分。针对 NetApp junction 重现该情况，并将其与使用 FSCTL_GET_REPARSE_POINT 的 DeviceIoControl 进行比较。完成的标准是 st_reparse_tag 报告远程 junction 的 reparse tag，同时保持对普通 Windows 共享的行为不变。