"docker cp" not working when bind mounting cgroup dir with btrfs storage driver #38252
Description
BUG REPORT INFORMATION
Description
Since 18.09 version, docker cp is not working at all for container with /sys/fs/cgroup bind mounted and if storage driver is btrfs. By bind mounting another dir, or by using vfs or overlay2, it is working fine.
Steps to reproduce the issue:
docker run -ti --name test --mount type=bind,source=/sys/fs/cgroup,target=/sys/fs/cgroup,readonly centos /usr/bin/echo createdtouch foo.filedocker cp foo.file test:/tmp
Describe the results you received:
Error response from daemon: invalid argument
Describe the results you expected:
It should copy foo.file into the test container in /tmp
Additional information you deem important (e.g. issue happens only occasionally):
--mount type=bind,source=/sys/fs/cgroup,target=/sys/fs/cgroup,readonly and BTRFS storage driver are both needed to trigger the bug.
Output of docker version:
Client:
Version: 18.09.0-ce
API version: 1.39
Go version: go1.11.2
Git commit: 4d60db472b
Built: Fri Nov 9 00:05:34 2018
OS/Arch: linux/amd64
Experimental: false
Server:
Engine:
Version: 18.09.0-ce
API version: 1.39 (minimum version 1.12)
Go version: go1.11.2
Git commit: 4d60db472b
Built: Fri Nov 9 00:05:11 2018
OS/Arch: linux/amd64
Experimental: false
Output of docker info:
Containers: 8
Running: 1
Paused: 0
Stopped: 7
Images: 4
Server Version: 18.09.0-ce
Storage Driver: btrfs
Build Version: Btrfs v4.19
Library Version: 102
Logging Driver: journald
Cgroup Driver: cgroupfs
Plugins:
Volume: local
Network: bridge host macvlan null overlay
Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 9f2e07b1fc1342d1c48fe4d7bbb94cb6d1bf278b.m
runc version: 079817cc26ec5292ac375bb9f47f373d33574949
init version: fec3683
Security Options:
seccomp
Profile: default
Kernel Version: 4.19.2-arch1-1-ARCH
Operating System: Arch Linux
OSType: linux
Architecture: x86_64
CPUs: 8
Total Memory: 15.4GiB
Name: sb-makeorg
ID: 5Q6O:FKV5:4LDG:YAKS:LNP2:XAVS:KVJJ:SRE5:MR77:NIDL:W6WX:E3CJ
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): false
Username: sbernard
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false
Additional environment details (AWS, VirtualBox, physical, etc.):
physical laptop