libct/cg: IsCgroup2HybridMode: don't panic #3433
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kolyshkin
added
area/cgroupv1
backport/1.1-todo
|
As a library we should avoid logging but I think this case is probably fine. |
mrunalp
previously approved these changes
Mar 27, 2022
liggitt
reviewed
Mar 27, 2022
In case statfs("/sys/fs/cgroup/unified") fails with any error other
than ENOENT, current code panics. As IsCgroup2HybridMode is called from
libcontainer/cgroups/fs's init function, this means that any user of
libcontainer may panic during initialization, which is ugly.
Avoid panicking; instead, do not enable hybrid hierarchy support and
report the error (under debug level, not to confuse anyone).
Basically, replace the panic with "turn off hybrid mode support"
(which makes total sense since we were unable to statfs its root).
Signed-off-by: Kir Kolyshkin <[email protected]>
Good point! There are a bunch of other places like this in libcontainer unfortunately. Which has to be solved globally (perhaps by having a user-specifiable logger which defaults to "no logging at all". |
mrunalp
approved these changes
Mar 27, 2022
AkihiroSuda
approved these changes
Mar 28, 2022
kolyshkin
added
backport/1.1-done
|
1.1 backport: #3435 |
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In case
statfs("/sys/fs/cgroup/unified")fails with any error otherthan
ENOENT, current code panics. AsIsCgroup2HybridModeis called fromlibcontainer/cgroups/fs'sinitfunction, this means that any user oflibcontainer may panic during initialization, which is ugly.
Avoid panicking; instead, do not enable hybrid hierarchy support and
report the error (under debug level, not to confuse anyone).
Basically, replace the panic with "turn off hybrid mode support"
(which makes total sense since we were unable to statfs its root).
This is an alternative to #3432. The bug is originally reported by @liggitt
in kubernetes/kubernetes#109029 (review)