86 lines
2.3 KiB
Go
86 lines
2.3 KiB
Go
/*
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Copyright 2024 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package swap
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import (
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"os"
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sysruntime "runtime"
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"sync"
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"k8s.io/apimachinery/pkg/util/version"
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"k8s.io/klog/v2"
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utilkernel "k8s.io/kubernetes/pkg/util/kernel"
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"k8s.io/mount-utils"
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)
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var (
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tmpfsNoswapOptionSupported bool
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tmpfsNoswapOptionAvailabilityOnce sync.Once
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)
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const TmpfsNoswapOption = "noswap"
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func IsTmpfsNoswapOptionSupported(mounter mount.Interface) bool {
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isTmpfsNoswapOptionSupportedHelper := func() bool {
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if sysruntime.GOOS == "windows" {
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return false
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}
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kernelVersion, err := utilkernel.GetVersion()
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if err != nil {
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klog.ErrorS(err, "cannot determine kernel version, unable to determine is tmpfs noswap is supported")
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return false
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}
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if kernelVersion.AtLeast(version.MustParseGeneric(utilkernel.TmpfsNoswapSupportKernelVersion)) {
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return true
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}
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mountDir, err := os.MkdirTemp("", "tmpfs-noswap-test-")
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if err != nil {
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klog.InfoS("error creating dir to test if tmpfs noswap is enabled. Assuming not supported", "mount path", mountDir, "error", err)
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return false
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}
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defer func() {
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err = os.RemoveAll(mountDir)
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if err != nil {
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klog.ErrorS(err, "error removing test tmpfs dir", "mount path", mountDir)
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}
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}()
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err = mounter.MountSensitiveWithoutSystemd("tmpfs", mountDir, "tmpfs", []string{TmpfsNoswapOption}, nil)
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if err != nil {
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klog.InfoS("error mounting tmpfs with the noswap option. Assuming not supported", "error", err)
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return false
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}
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err = mounter.Unmount(mountDir)
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if err != nil {
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klog.ErrorS(err, "error unmounting test tmpfs dir", "mount path", mountDir)
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}
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return true
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}
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tmpfsNoswapOptionAvailabilityOnce.Do(func() {
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tmpfsNoswapOptionSupported = isTmpfsNoswapOptionSupportedHelper()
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})
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return tmpfsNoswapOptionSupported
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}
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