mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-09-19 15:09:56 +00:00
a95a6213eb
With cgroup v2, the location of the pids.max file changed and so did the /proc/self/cgroup file new /proc/self/cgroup file ` 0::/user.slice/user-500.slice/session-14.scope ` old file: ` 11:pids:/user.slice/user-500.slice/session-2.scope 10:blkio:/user.slice 9:net_cls,net_prio:/ 8:perf_event:/ ... ` There is no directory per subsystem (e.g. /sys/fs/cgroup/pids) any more, all files are now in one directory. fixes: https://github.com/ceph/ceph-csi/issues/3085 Signed-off-by: Marcus Röder <m.roeder@yieldlab.de>
137 lines
3.2 KiB
Go
137 lines
3.2 KiB
Go
/*
|
|
Copyright 2019 The Ceph-CSI Authors.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package util
|
|
|
|
import (
|
|
"bufio"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
const (
|
|
procCgroup = "/proc/self/cgroup"
|
|
sysPidsMaxFmtCgroupV1 = "/sys/fs/cgroup/pids%s/pids.max"
|
|
sysPidsMaxFmtCgroupV2 = "/sys/fs/cgroup%s/pids.max"
|
|
)
|
|
|
|
// getCgroupPidsFile return the cgroups "pids.max" file of the
|
|
// current process
|
|
// For cgroup v1, find the line containing the pids group from the /proc/self/cgroup file
|
|
// $ grep ':pids:' /proc/self/cgroup
|
|
// 7:pids:/kubepods.slice/kubepods-besteffort.slice/....scope
|
|
// $ cat /sys/fs/cgroup/pids + *.scope + /pids.max.
|
|
// The entry for cgroup v2 is always in the format "0::...scope", no subsystem given.
|
|
// (see https://www.kernel.org/doc/Documentation/cgroup-v2.txt)
|
|
func getCgroupPidsFile() (string, error) {
|
|
cgroup, err := os.Open(procCgroup)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
defer cgroup.Close() // #nosec: error on close is not critical here
|
|
|
|
pidsMax := ""
|
|
scanner := bufio.NewScanner(cgroup)
|
|
var slice string
|
|
for scanner.Scan() {
|
|
parts := strings.SplitN(scanner.Text(), ":", 3)
|
|
if parts == nil || len(parts) < 3 {
|
|
continue
|
|
}
|
|
// No cgroup subsystem given, then it is cgroupv2
|
|
if parts[0] == "0" && parts[1] == "" {
|
|
slice = parts[2]
|
|
pidsMax = fmt.Sprintf(sysPidsMaxFmtCgroupV2, slice)
|
|
|
|
break
|
|
}
|
|
if parts[1] == "pids" {
|
|
slice = parts[2]
|
|
pidsMax = fmt.Sprintf(sysPidsMaxFmtCgroupV1, slice)
|
|
|
|
break
|
|
}
|
|
}
|
|
if slice == "" {
|
|
return "", fmt.Errorf("could not find a cgroup for 'pids'")
|
|
}
|
|
|
|
return pidsMax, nil
|
|
}
|
|
|
|
// GetPIDLimit returns the current PID limit, or an error. A value of -1
|
|
// translates to "max".
|
|
func GetPIDLimit() (int, error) {
|
|
pidsMax, err := getCgroupPidsFile()
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
f, err := os.Open(pidsMax) // #nosec - intended reading from /sys/...
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
defer f.Close() // #nosec: error on close is not critical here
|
|
|
|
maxPidsStr, err := bufio.NewReader(f).ReadString('\n')
|
|
if err != nil && !errors.Is(err, io.EOF) {
|
|
return 0, err
|
|
}
|
|
maxPidsStr = strings.TrimRight(maxPidsStr, "\n")
|
|
|
|
maxPids := -1
|
|
if maxPidsStr != "max" {
|
|
maxPids, err = strconv.Atoi(maxPidsStr)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
}
|
|
|
|
return maxPids, nil
|
|
}
|
|
|
|
// SetPIDLimit configures the given PID limit for the current process. A value
|
|
// of -1 translates to "max".
|
|
func SetPIDLimit(limit int) error {
|
|
limitStr := "max"
|
|
if limit != -1 {
|
|
limitStr = fmt.Sprintf("%d", limit)
|
|
}
|
|
|
|
pidsMax, err := getCgroupPidsFile()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
f, err := os.Create(pidsMax)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
_, err = f.WriteString(limitStr)
|
|
if err != nil {
|
|
f.Close() // #nosec: a write error will be more useful to return
|
|
|
|
return err
|
|
}
|
|
|
|
return f.Close()
|
|
}
|