mirror of
https://github.com/opencontainers/runc.git
synced 2026-07-11 06:03:57 +08:00
Aleksa Sarai
3b75374cc7
The main update is actually in github.com/opencontainers/cgroups, but we need to also update runtime-spec to a newer pre-release version to get the updates from there as well. In short, the behaviour change is now that "0" is treated as a valid value to set in "pids.max", "-1" means "max" and unset/nil means "do nothing". As described in the opencontainers/cgroups PR, this change is actually backwards compatible because our internal state.json stores PidsLimit, and that entry is marked as "omitempty". So, an old runc would omit PidsLimit=0 in state.json, and this will be parsed by a new runc as being "nil" -- and both would treat this case as "do not set anything". Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
67 lines
1.5 KiB
Go
67 lines
1.5 KiB
Go
package fs
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import (
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"math"
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"strconv"
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"github.com/opencontainers/cgroups"
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"github.com/opencontainers/cgroups/fscommon"
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)
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type PidsGroup struct{}
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func (s *PidsGroup) Name() string {
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return "pids"
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}
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func (s *PidsGroup) Apply(path string, _ *cgroups.Resources, pid int) error {
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return apply(path, pid)
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}
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func (s *PidsGroup) Set(path string, r *cgroups.Resources) error {
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if r.PidsLimit == nil {
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return nil
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}
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// "max" is the fallback value.
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val := "max"
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if limit := *r.PidsLimit; limit > 0 {
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val = strconv.FormatInt(limit, 10)
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} else if limit == 0 {
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// systemd doesn't support setting pids.max to "0", so when setting
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// TasksMax we need to remap it to "1". We do the same thing here to
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// avoid flip-flop behaviour between the fs and systemd drivers. In
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// practice, the pids cgroup behaviour is basically identical.
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val = "1"
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}
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if err := cgroups.WriteFile(path, "pids.max", val); err != nil {
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return err
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}
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return nil
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}
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func (s *PidsGroup) GetStats(path string, stats *cgroups.Stats) error {
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if !cgroups.PathExists(path) {
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return nil
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}
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current, err := fscommon.GetCgroupParamUint(path, "pids.current")
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if err != nil {
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return err
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}
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max, err := fscommon.GetCgroupParamUint(path, "pids.max")
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if err != nil {
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return err
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}
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// If no limit is set, read from pids.max returns "max", which is
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// converted to MaxUint64 by GetCgroupParamUint. Historically, we
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// represent "no limit" for pids as 0, thus this conversion.
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if max == math.MaxUint64 {
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max = 0
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}
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stats.PidsStats.Current = current
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stats.PidsStats.Limit = max
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return nil
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}
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