path/filepath: EvalSymlinks of a directory which is mapped from volumeID (instead of drive letter) does not work

[jingxu97]

What version of Go are you using (go version)?

go 1.13

$ go version

Does this issue reproduce with the latest release?

Not tested

What operating system and processor architecture are you using (go env)?

set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GOOS=windows

go env Output

$ go env

What did you do?

Create a symlink from volume id
mklink /D \my\path \?\Volume{1b3b1146-4076-11e1-84aa-806e6f6e6963}\

Running filepath.EvalSymlinks against a symlink (\my\path) which is created from a volumeid returns the following error:

too many links!

What did you expect to see?

What did you see instead?

[cagedmantis]

/cc @robpike @rsc

[jingxu97]

I found a way to use Powershell command to workaround this issue in kubernetes code.
kubernetes/kubernetes#92328

[networkimprov]

EDIT: Related: #39785

cc @alexbrainman @bcmills

@gopherbot add OS-Windows

[gopherbot]

Change https://golang.org/cl/241278 mentions this issue: path/filepath: try GetFinalPathNameByHandle with VOLUME_NAME_GUID

[networkimprov]

@ericwj can you look at fixing #39785 in your fix for this?

Also, if you're interested in fixing other GOOS=windows issues, there's a handful I could point you to :-)

[ericwj]

Man I am so annoyed about this for years now that I learned Go just to fix this - I've written about 100 lines total now...

[ericwj]

Consider weighing in on #40104 to see issues like this finally be resolved once and forever.

[alexbrainman]

@jingxu97

I tried reproducing your problem on current tip (it will be part of go1.15 soon), and I cannot. In particular, I tried an existing Go library test, that does exactly what you are describing in this issue.

c:\>go version
go version devel +3a4322627e Fri Jul 10 11:32:36 2020 +0000 windows/amd64

c:\>go test -v -run=NTName path/filepath
=== RUN   TestNTNamespaceSymlink
--- PASS: TestNTNamespaceSymlink (0.06s)
PASS
ok      path/filepath   0.087s

c:\>

Can you, please, try to run this test yourself (you will have to be the Administrator) and tell us, if it fails or passes? If you think your situation is different, then, please, provide complete reproduction steps, and not just vague description.

Thank you.

Alex