How can I get access to files transferred from Windows to WSL-2 Ubuntu?

Question

I have a Linux subsystem installed on my Windows machine. I've transferred a tar.gz file I want to access by finding the location of my subsystem and dragging the files over. But when I run the command:

tar -zxvf file_name.tar.gz

I get the error:

tar (child): vmd-1.9.4a51.bin.LINUXAMD64-CUDA102-OptiX650-OSPRay185.opengl.tar.gz: Cannot open: Permission denied
tar (child): Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error is not recoverable: exiting now

I assume permission being denied is to do with having transferred from Windows since I couldn't access directories I created through Windows either. So, is there something I need to change to gain access to these files?

(PS. I know there are other way of getting tar.gz files other than transferring from Windows, but I'll need to do this for other folders too, I only included the filetype in case it was relevant .)

EDIT: You shouldn't attempt to drag files over. See answer below.

Answer 1

For starters, this belongs on Super User since it doesn't deal directly with a programming question. But since you've already provide an answer here that may be slightly dangerous (and even in your question), I didn't want to leave this unanswered for other people to find inadvertently.

If you used the first method in that link, you are using a WSL1 instance, not WSL2. Only WSL1 made the filesystem available in that way. And it's a really, really bad idea:

There is one hard-and-fast rule when it comes to WSL on Windows:

DO NOT, under ANY circumstances, access, create, and/or modify Linux files inside of your %LOCALAPPDATA% folder using Windows apps, tools, scripts, consoles, etc.

Opening files using some Windows tools may read-lock the opened files and/or folders, preventing updates to file contents and/or metadata, essentially resulting in corrupted files/folders.

I'm guessing you probably went through the install process for WSL2, but you installed your distribution before setting wsl --set-default-version 2 or something like that.

As you can see in the Microsoft link above, there's now a safe method for transferring and editing files between Windows and WSL - the \\wsl$\ tmpfs mounts. Note that as a tmpfs mount stored in memory, it's really more for transferring files over. They will disappear when you reboot or shutdown WSL.

But even if you'd used the second method in that article (/mnt/c), you probably would have run into permissions issues. If you do, the solution should be to remount the C: drive with your uid/gid as I describe here.