mirror of
https://github.com/minio/minio.git
synced 2024-12-25 06:35:56 -05:00
e85b28398b
Avoids append() based tiny allocations on known allocated slices repeated access.
283 lines
7.7 KiB
Go
283 lines
7.7 KiB
Go
/*
|
|
* MinIO Cloud Storage, (C) 2016-2021 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 globalLockServer *localLocker
|
|
|
|
// RWLocker - locker interface to introduce GetRLock, RUnlock.
|
|
type RWLocker interface {
|
|
GetLock(ctx context.Context, timeout *dynamicTimeout) (newCtx context.Context, timedOutErr error)
|
|
Unlock()
|
|
GetRLock(ctx context.Context, timeout *dynamicTimeout) (newCtx context.Context, 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) (context.Context, error) {
|
|
lockSource := getSource(2)
|
|
start := UTCNow()
|
|
|
|
newCtx, cancel := context.WithCancel(ctx)
|
|
if !di.rwMutex.GetLock(newCtx, cancel, di.opsID, lockSource, dsync.Options{
|
|
Timeout: timeout.Timeout(),
|
|
}) {
|
|
timeout.LogFailure()
|
|
return ctx, OperationTimedOut{}
|
|
}
|
|
timeout.LogSuccess(UTCNow().Sub(start))
|
|
return newCtx, 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) (context.Context, error) {
|
|
lockSource := getSource(2)
|
|
start := UTCNow()
|
|
|
|
newCtx, cancel := context.WithCancel(ctx)
|
|
if !di.rwMutex.GetRLock(ctx, cancel, di.opsID, lockSource, dsync.Options{
|
|
Timeout: timeout.Timeout(),
|
|
}) {
|
|
timeout.LogFailure()
|
|
return ctx, OperationTimedOut{}
|
|
}
|
|
timeout.LogSuccess(UTCNow().Sub(start))
|
|
return newCtx, 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) (_ context.Context, timedOutErr error) {
|
|
lockSource := getSource(2)
|
|
start := UTCNow()
|
|
const readLock = false
|
|
success := make([]int, len(li.paths))
|
|
for i, path := range li.paths {
|
|
if !li.ns.lock(ctx, li.volume, path, lockSource, li.opsID, readLock, timeout.Timeout()) {
|
|
timeout.LogFailure()
|
|
for si, sint := range success {
|
|
if sint == 1 {
|
|
li.ns.unlock(li.volume, li.paths[si], readLock)
|
|
}
|
|
}
|
|
return nil, OperationTimedOut{}
|
|
}
|
|
success[i] = 1
|
|
}
|
|
timeout.LogSuccess(UTCNow().Sub(start))
|
|
return ctx, nil
|
|
}
|
|
|
|
// 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) (_ context.Context, timedOutErr error) {
|
|
lockSource := getSource(2)
|
|
start := UTCNow()
|
|
const readLock = true
|
|
success := make([]int, len(li.paths))
|
|
for i, path := range li.paths {
|
|
if !li.ns.lock(ctx, li.volume, path, lockSource, li.opsID, readLock, timeout.Timeout()) {
|
|
timeout.LogFailure()
|
|
for si, sint := range success {
|
|
if sint == 1 {
|
|
li.ns.unlock(li.volume, li.paths[si], readLock)
|
|
}
|
|
}
|
|
return nil, OperationTimedOut{}
|
|
}
|
|
success[i] = 1
|
|
}
|
|
timeout.LogSuccess(UTCNow().Sub(start))
|
|
return ctx, nil
|
|
}
|
|
|
|
// 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)
|
|
}
|