EINVAL on access(sys/fs/cgroup/systemd) since 2.0.0.rc8

[sts]

Since lxcfs 2.0.0.rc8 the lxcfs fuse module overrides the access method and erroneously returns EINVAL when systemd in Debian/Jessie (215-17) tries to check access for /sys/fs/cgroup/systemd: This prevents successful startup of systemd:

access("/sys/fs/cgroup/systemd", F_OK) = -1 EINVAL (Invalid argument)

I'm attaching a strace of systemd during startup before it gets stuck at pause().

strace_systemd_215-17_lxcfs_2.0.0.rc8.txt

[sts]

@hallyn committed a patch yesterday, changing the return value to EACCES, but after testing it did not resolve our issue.

Again, attached is a strace of systemd during startup before it gets stuck at pause():

strace_systemd_215-17_lxcfs_575316c4706e5600f3935e8245027f7de6222656.txt

[sts]

I'm also attaching an strace of sytemd 215-17 during a successful startup with lxcfs 2.0.0.rc7! access() seems to return 0.

strace_systemd_215-17_lxcfs_2.0.0.rc7.txt

[sts]

@hallyn sorry, the fix still did not resolve the issue. Its still returning:

access("/sys/fs/cgroup/systemd", F_OK)  = -1 EACCES (Permission denied)

[hallyn]

Odd. It works for me here. can you strace lxcfs itself, do the access, and show the strace output here?

[hallyn]

Ok, I guess strace isn't very helpful. Better would be to run it in gdb and trace through the cg_attach() function to see where it returns the EACCESS.

[sts]

Sorry there was a issue when applying the patch to our Debian package build. Commit 3f441bc actually already fixed it!