/host_mnt prepended to volume mount prevents container running

[pwrightkcl]

Description

After adding a directory to File sharing, it can be used as a volume mount for a container at first, but after restarting Docker Desktop, the container fails to run. It gives a 'permission denied' error with '/host_mnt' prepended to the local path in the volume mount.

This is happening in Linux. I have seen other issues relating to '/host_mnt' in Windows and Mac, but they do not appear to apply here.

Reproduce

1. Add a directory under Settings -> Resources -> File sharing.
2. Start a container using that directory in a volume mount. It will run as expected.
3. Restart Docker Desktop
4. Start the container as before, this time there will be an error as below:

docker: Error response from daemon: error while creating mount source path '/host_mnt/path/to/local/directory': mkdir /host_mnt/path/to/local/directory: permission denied.
ERRO[0020] error waiting for container: 

In this example, /path/to/local/directory exists and was mountable the first time the container was run.

Expected behavior

Docker Desktop should run the container the same every time, rather working at first then failing after a restart.

docker version

Client: Docker Engine - Community
 Cloud integration: v1.0.33
 Version:           24.0.2
 API version:       1.43
 Go version:        go1.20.4
 Git commit:        cb74dfc
 Built:             Thu May 25 21:51:00 2023
 OS/Arch:           linux/amd64
 Context:           desktop-linux

Server: Docker Desktop 4.20.0 (109717)
 Engine:
  Version:          24.0.2
  API version:      1.43 (minimum version 1.12)
  Go version:       go1.20.4
  Git commit:       659604f
  Built:            Thu May 25 21:52:17 2023
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.21
  GitCommit:        3dce8eb055cbb6872793272b4f20ed16117344f8
 runc:
  Version:          1.1.7
  GitCommit:        v1.1.7-0-g860f061
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

Client: Docker Engine - Community
 Version:    24.0.2
 Context:    desktop-linux
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  v0.10.5
    Path:     /usr/lib/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  v2.18.1
    Path:     /usr/lib/docker/cli-plugins/docker-compose
  dev: Docker Dev Environments (Docker Inc.)
    Version:  v0.1.0
    Path:     /usr/lib/docker/cli-plugins/docker-dev
  extension: Manages Docker extensions (Docker Inc.)
    Version:  v0.2.19
    Path:     /usr/lib/docker/cli-plugins/docker-extension
  init: Creates Docker-related starter files for your project (Docker Inc.)
    Version:  v0.1.0-beta.4
    Path:     /usr/lib/docker/cli-plugins/docker-init
  sbom: View the packaged-based Software Bill Of Materials (SBOM) for an image (Anchore Inc.)
    Version:  0.6.0
    Path:     /usr/lib/docker/cli-plugins/docker-sbom
  scan: Docker Scan (Docker Inc.)
    Version:  v0.26.0
    Path:     /usr/lib/docker/cli-plugins/docker-scan
  scout: Command line tool for Docker Scout (Docker Inc.)
    Version:  v0.12.0
    Path:     /usr/lib/docker/cli-plugins/docker-scout

Server:
 Containers: 1
  Running: 0
  Paused: 0
  Stopped: 1
 Images: 1
 Server Version: 24.0.2
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: false
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: runc io.containerd.runc.v2
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 3dce8eb055cbb6872793272b4f20ed16117344f8
 runc version: v1.1.7-0-g860f061
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 5.15.49-linuxkit-pr
 Operating System: Docker Desktop
 OSType: linux
 Architecture: x86_64
 CPUs: 8
 Total Memory: 7.674GiB
 Name: docker-desktop
 ID: e161c262-9ad4-428b-bab1-f4db1c2f64e3
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 HTTP Proxy: http.docker.internal:3128
 HTTPS Proxy: http.docker.internal:3128
 No Proxy: hubproxy.docker.internal
 Username: pwrightkcl
 Experimental: false
 Insecure Registries:
  hubproxy.docker.internal:5555
  127.0.0.0/8
 Live Restore Enabled: false

Diagnostics ID

6bbcfa55-ce44-4f40-881a-94fd86efca19/20230602154524

Additional Info

The directory I am using is on a device formatted NTFS and shared between Linux and Windows on this machine, which may be relevant.

[pwrightkcl]

I moved my data to an EXT4 filesystem on the same system, and this problem does not occur. I restarted Docker Desktop, and the containers ran as before, whether started from Desktop or command line.

It looks like the issue is to do with the mount point being on a filesystem in NTFS format. Perhaps DD sees an NTFS filesystem and assumes it is running in Windows, hence adding the '/host_mnt' prefix. In that case, there needs to be an extra test of the actual OS it is running in, not just the filesystem being mounted (or perhaps only the former). The use case of a system dual booting Linux and Windows, with a data drive formatted NTFS so both can share cannot be that uncommon.

Note that the NTFS drive is used for data only. I have an EXT4 SSD where Linux is installed, and Docker and DD are also installed there. I have a separate EXT4 HDD in use as my Docker registry, since it refused to work on my NTFS HDD when I set up my base Docker installation way back when.