2294e53a0b
Use the context for internal timeouts, but disconnect it from outgoing calls so we always receive the results and cancel it remotely.
277 lines
7.4 KiB
Go
277 lines
7.4 KiB
Go
/*
|
|
* MinIO Cloud Storage, (C) 2016, 2017, 2018, 2019 MinIO, Inc.
|
|
*
|
|
* 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 cmd
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
pathutil "path"
|
|
"runtime"
|
|
"sort"
|
|
"strings"
|
|
"sync"
|
|
|
|
"fmt"
|
|
"time"
|
|
|
|
"github.com/minio/minio/cmd/logger"
|
|
"github.com/minio/minio/pkg/dsync"
|
|
"github.com/minio/minio/pkg/lsync"
|
|
)
|
|
|
|
// local lock servers
|
|
var globalLockServers = make(map[Endpoint]*localLocker)
|
|
|
|
// RWLocker - locker interface to introduce GetRLock, RUnlock.
|
|
type RWLocker interface {
|
|
GetLock(ctx context.Context, timeout *dynamicTimeout) (timedOutErr error)
|
|
Unlock()
|
|
GetRLock(ctx context.Context, timeout *dynamicTimeout) (timedOutErr error)
|
|
RUnlock()
|
|
}
|
|
|
|
// newNSLock - return a new name space lock map.
|
|
func newNSLock(isDistErasure bool) *nsLockMap {
|
|
nsMutex := nsLockMap{
|
|
isDistErasure: isDistErasure,
|
|
}
|
|
if isDistErasure {
|
|
return &nsMutex
|
|
}
|
|
nsMutex.lockMap = make(map[string]*nsLock)
|
|
return &nsMutex
|
|
}
|
|
|
|
// nsLock - provides primitives for locking critical namespace regions.
|
|
type nsLock struct {
|
|
ref int32
|
|
*lsync.LRWMutex
|
|
}
|
|
|
|
// nsLockMap - namespace lock map, provides primitives to Lock,
|
|
// Unlock, RLock and RUnlock.
|
|
type nsLockMap struct {
|
|
// Indicates if namespace is part of a distributed setup.
|
|
isDistErasure bool
|
|
lockMap map[string]*nsLock
|
|
lockMapMutex sync.Mutex
|
|
}
|
|
|
|
// Lock the namespace resource.
|
|
func (n *nsLockMap) lock(ctx context.Context, volume string, path string, lockSource, opsID string, readLock bool, timeout time.Duration) (locked bool) {
|
|
resource := pathJoin(volume, path)
|
|
|
|
n.lockMapMutex.Lock()
|
|
nsLk, found := n.lockMap[resource]
|
|
if !found {
|
|
nsLk = &nsLock{
|
|
LRWMutex: lsync.NewLRWMutex(),
|
|
}
|
|
// Add a count to indicate that a parallel unlock doesn't clear this entry.
|
|
}
|
|
nsLk.ref++
|
|
n.lockMap[resource] = nsLk
|
|
n.lockMapMutex.Unlock()
|
|
|
|
// Locking here will block (until timeout).
|
|
if readLock {
|
|
locked = nsLk.GetRLock(ctx, opsID, lockSource, timeout)
|
|
} else {
|
|
locked = nsLk.GetLock(ctx, opsID, lockSource, timeout)
|
|
}
|
|
|
|
if !locked { // We failed to get the lock
|
|
// Decrement ref count since we failed to get the lock
|
|
n.lockMapMutex.Lock()
|
|
n.lockMap[resource].ref--
|
|
if n.lockMap[resource].ref < 0 {
|
|
logger.CriticalIf(GlobalContext, errors.New("resource reference count was lower than 0"))
|
|
}
|
|
if n.lockMap[resource].ref == 0 {
|
|
// Remove from the map if there are no more references.
|
|
delete(n.lockMap, resource)
|
|
}
|
|
n.lockMapMutex.Unlock()
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
// Unlock the namespace resource.
|
|
func (n *nsLockMap) unlock(volume string, path string, readLock bool) {
|
|
resource := pathJoin(volume, path)
|
|
|
|
n.lockMapMutex.Lock()
|
|
defer n.lockMapMutex.Unlock()
|
|
if _, found := n.lockMap[resource]; !found {
|
|
return
|
|
}
|
|
if readLock {
|
|
n.lockMap[resource].RUnlock()
|
|
} else {
|
|
n.lockMap[resource].Unlock()
|
|
}
|
|
n.lockMap[resource].ref--
|
|
if n.lockMap[resource].ref < 0 {
|
|
logger.CriticalIf(GlobalContext, errors.New("resource reference count was lower than 0"))
|
|
}
|
|
if n.lockMap[resource].ref == 0 {
|
|
// Remove from the map if there are no more references.
|
|
delete(n.lockMap, resource)
|
|
}
|
|
}
|
|
|
|
// dsync's distributed lock instance.
|
|
type distLockInstance struct {
|
|
rwMutex *dsync.DRWMutex
|
|
opsID string
|
|
}
|
|
|
|
// Lock - block until write lock is taken or timeout has occurred.
|
|
func (di *distLockInstance) GetLock(ctx context.Context, timeout *dynamicTimeout) (timedOutErr error) {
|
|
lockSource := getSource(2)
|
|
start := UTCNow()
|
|
|
|
if !di.rwMutex.GetLock(ctx, di.opsID, lockSource, dsync.Options{
|
|
Timeout: timeout.Timeout(),
|
|
}) {
|
|
timeout.LogFailure()
|
|
return OperationTimedOut{}
|
|
}
|
|
timeout.LogSuccess(UTCNow().Sub(start))
|
|
return nil
|
|
}
|
|
|
|
// Unlock - block until write lock is released.
|
|
func (di *distLockInstance) Unlock() {
|
|
di.rwMutex.Unlock()
|
|
}
|
|
|
|
// RLock - block until read lock is taken or timeout has occurred.
|
|
func (di *distLockInstance) GetRLock(ctx context.Context, timeout *dynamicTimeout) (timedOutErr error) {
|
|
lockSource := getSource(2)
|
|
start := UTCNow()
|
|
|
|
if !di.rwMutex.GetRLock(ctx, di.opsID, lockSource, dsync.Options{
|
|
Timeout: timeout.Timeout(),
|
|
}) {
|
|
timeout.LogFailure()
|
|
return OperationTimedOut{}
|
|
}
|
|
timeout.LogSuccess(UTCNow().Sub(start))
|
|
return nil
|
|
}
|
|
|
|
// RUnlock - block until read lock is released.
|
|
func (di *distLockInstance) RUnlock() {
|
|
di.rwMutex.RUnlock()
|
|
}
|
|
|
|
// localLockInstance - frontend/top-level interface for namespace locks.
|
|
type localLockInstance struct {
|
|
ns *nsLockMap
|
|
volume string
|
|
paths []string
|
|
opsID string
|
|
}
|
|
|
|
// NewNSLock - returns a lock instance for a given volume and
|
|
// path. The returned lockInstance object encapsulates the nsLockMap,
|
|
// volume, path and operation ID.
|
|
func (n *nsLockMap) NewNSLock(lockers func() ([]dsync.NetLocker, string), volume string, paths ...string) RWLocker {
|
|
opsID := mustGetUUID()
|
|
if n.isDistErasure {
|
|
drwmutex := dsync.NewDRWMutex(&dsync.Dsync{
|
|
GetLockers: lockers,
|
|
}, pathsJoinPrefix(volume, paths...)...)
|
|
return &distLockInstance{drwmutex, opsID}
|
|
}
|
|
sort.Strings(paths)
|
|
return &localLockInstance{n, volume, paths, opsID}
|
|
}
|
|
|
|
// Lock - block until write lock is taken or timeout has occurred.
|
|
func (li *localLockInstance) GetLock(ctx context.Context, timeout *dynamicTimeout) (timedOutErr error) {
|
|
lockSource := getSource(2)
|
|
start := UTCNow()
|
|
const readLock = false
|
|
var success []int
|
|
for i, path := range li.paths {
|
|
if !li.ns.lock(ctx, li.volume, path, lockSource, li.opsID, readLock, timeout.Timeout()) {
|
|
timeout.LogFailure()
|
|
for _, sint := range success {
|
|
li.ns.unlock(li.volume, li.paths[sint], readLock)
|
|
}
|
|
return OperationTimedOut{}
|
|
}
|
|
success = append(success, i)
|
|
}
|
|
timeout.LogSuccess(UTCNow().Sub(start))
|
|
return
|
|
}
|
|
|
|
// Unlock - block until write lock is released.
|
|
func (li *localLockInstance) Unlock() {
|
|
const readLock = false
|
|
for _, path := range li.paths {
|
|
li.ns.unlock(li.volume, path, readLock)
|
|
}
|
|
}
|
|
|
|
// RLock - block until read lock is taken or timeout has occurred.
|
|
func (li *localLockInstance) GetRLock(ctx context.Context, timeout *dynamicTimeout) (timedOutErr error) {
|
|
lockSource := getSource(2)
|
|
start := UTCNow()
|
|
const readLock = true
|
|
var success []int
|
|
for i, path := range li.paths {
|
|
if !li.ns.lock(ctx, li.volume, path, lockSource, li.opsID, readLock, timeout.Timeout()) {
|
|
timeout.LogFailure()
|
|
for _, sint := range success {
|
|
li.ns.unlock(li.volume, li.paths[sint], readLock)
|
|
}
|
|
return OperationTimedOut{}
|
|
}
|
|
success = append(success, i)
|
|
}
|
|
timeout.LogSuccess(UTCNow().Sub(start))
|
|
return
|
|
}
|
|
|
|
// RUnlock - block until read lock is released.
|
|
func (li *localLockInstance) RUnlock() {
|
|
const readLock = true
|
|
for _, path := range li.paths {
|
|
li.ns.unlock(li.volume, path, readLock)
|
|
}
|
|
}
|
|
|
|
func getSource(n int) string {
|
|
var funcName string
|
|
pc, filename, lineNum, ok := runtime.Caller(n)
|
|
if ok {
|
|
filename = pathutil.Base(filename)
|
|
funcName = strings.TrimPrefix(runtime.FuncForPC(pc).Name(),
|
|
"github.com/minio/minio/cmd.")
|
|
} else {
|
|
filename = "<unknown>"
|
|
lineNum = 0
|
|
}
|
|
|
|
return fmt.Sprintf("[%s:%d:%s()]", filename, lineNum, funcName)
|
|
}
|