mirror of https://github.com/k3s-io/k3s
114 lines
2.8 KiB
Go
114 lines
2.8 KiB
Go
// Copyright 2016 Google Inc. All Rights Reserved.
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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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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package zfs
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import (
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"fmt"
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"sync"
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"time"
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zfs "github.com/mistifyio/go-zfs"
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"k8s.io/klog"
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)
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// zfsWatcher maintains a cache of filesystem -> usage stats for a
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// zfs filesystem
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type ZfsWatcher struct {
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filesystem string
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lock *sync.RWMutex
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cache map[string]uint64
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period time.Duration
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stopChan chan struct{}
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}
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// NewThinPoolWatcher returns a new ThinPoolWatcher for the given devicemapper
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// thin pool name and metadata device or an error.
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func NewZfsWatcher(filesystem string) (*ZfsWatcher, error) {
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return &ZfsWatcher{
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filesystem: filesystem,
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lock: &sync.RWMutex{},
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cache: make(map[string]uint64),
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period: 15 * time.Second,
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stopChan: make(chan struct{}),
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}, nil
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}
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// Start starts the ZfsWatcher.
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func (w *ZfsWatcher) Start() {
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err := w.Refresh()
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if err != nil {
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klog.Errorf("encountered error refreshing zfs watcher: %v", err)
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}
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for {
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select {
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case <-w.stopChan:
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return
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case <-time.After(w.period):
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start := time.Now()
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err = w.Refresh()
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if err != nil {
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klog.Errorf("encountered error refreshing zfs watcher: %v", err)
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}
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// print latency for refresh
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duration := time.Since(start)
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klog.V(5).Infof("zfs(%d) took %s", start.Unix(), duration)
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}
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}
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}
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// Stop stops the ZfsWatcher.
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func (w *ZfsWatcher) Stop() {
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close(w.stopChan)
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}
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// GetUsage gets the cached usage value of the given filesystem.
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func (w *ZfsWatcher) GetUsage(filesystem string) (uint64, error) {
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w.lock.RLock()
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defer w.lock.RUnlock()
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v, ok := w.cache[filesystem]
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if !ok {
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return 0, fmt.Errorf("no cached value for usage of filesystem %v", filesystem)
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}
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return v, nil
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}
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// Refresh performs a zfs get
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func (w *ZfsWatcher) Refresh() error {
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w.lock.Lock()
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defer w.lock.Unlock()
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newCache := make(map[string]uint64)
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parent, err := zfs.GetDataset(w.filesystem)
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if err != nil {
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klog.Errorf("encountered error getting zfs filesystem: %s: %v", w.filesystem, err)
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return err
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}
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children, err := parent.Children(0)
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if err != nil {
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klog.Errorf("encountered error getting children of zfs filesystem: %s: %v", w.filesystem, err)
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return err
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}
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for _, ds := range children {
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newCache[ds.Name] = ds.Used
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}
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w.cache = newCache
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return nil
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}
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