Docker Bind Mount: error while creating mount source path, permission denied

Question

I am trying to run the NVIDIA PyTorch container nvcr.io/nvidia/pytorch:22.01-py3 on a Linux system, and I need to mount a directory of the host system (that I have R/W access to) in the container. I know that I need to use bind mounts, and here's what I'm trying:

I'm in a directory /home/<user>/test, which has the directory dir-to-mount. (The <user> account is mine).

docker run -it -v $(pwd)/dir-to-mount:/workspace/target nvcr.io/nvidia/pytorch:22.01-py3

Here's the error output:

docker: Error response from daemon: error while creating mount source path '/home/<user>/test/dir-to-mount': mkdir /home/<user>/test: permission denied.
ERRO[0000] error waiting for container: context canceled

As far as I know, docker will only need to create the directory to be mounted if it doesn't exist already. Docker docs:

The file or directory does not need to exist on the Docker host already. It is created on demand if it does not yet exist.

I suspected that maybe the docker process does not have access; I tried chmod 777 with dir-to-mount as well as with test, but that made no difference.

So what's going wrong?

[Edit 1]
I am able to mount my user's entire home directory with the same command, but cannot mount other directories inside the home directory.

[Edit 2]
Here are the permissions:

• home directory: drwx------
• test: drwxrwxrwx
• dir-to-mount: drwxrwxrwx

Answer 1

Run the command with sudo as:

sudo docker run -it -v $(pwd)/dir-to-mount:/workspace/target nvcr.io/nvidia/pytorch:22.01-py3

Answer 2

It appears that I can mount my home directory as a home directory (inside of /home/<username>), and this just works.

docker run -it -v $HOME:$HOME nvcr.io/nvidia/pytorch:22.01-py3

I don't know why the /home/<username> path is special, I've tried looking through the docs but I could not find anything relevant.