using isServerResolvable for expiration can lead to chicken and egg problems, a lock might expire knowingly when server is booting up causing perpetual locks getting expired.
400 lines
10 KiB
Go
400 lines
10 KiB
Go
/*
|
|
* Minio Cloud Storage, (C) 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 (
|
|
"bufio"
|
|
"context"
|
|
"errors"
|
|
"math/rand"
|
|
"net/http"
|
|
"sort"
|
|
"strconv"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/gorilla/mux"
|
|
"github.com/minio/minio/pkg/dsync"
|
|
)
|
|
|
|
const (
|
|
// Lock maintenance interval.
|
|
lockMaintenanceInterval = 1 * time.Minute
|
|
|
|
// Lock validity check interval.
|
|
lockValidityCheckInterval = 30 * time.Second
|
|
)
|
|
|
|
// To abstract a node over network.
|
|
type lockRESTServer struct {
|
|
ll *localLocker
|
|
}
|
|
|
|
func (l *lockRESTServer) writeErrorResponse(w http.ResponseWriter, err error) {
|
|
w.WriteHeader(http.StatusForbidden)
|
|
w.Write([]byte(err.Error()))
|
|
}
|
|
|
|
// IsValid - To authenticate and verify the time difference.
|
|
func (l *lockRESTServer) IsValid(w http.ResponseWriter, r *http.Request) bool {
|
|
if l.ll == nil {
|
|
l.writeErrorResponse(w, errLockNotInitialized)
|
|
return false
|
|
}
|
|
|
|
if err := storageServerRequestValidate(r); err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return false
|
|
}
|
|
return true
|
|
}
|
|
|
|
func getLockArgs(r *http.Request) (args dsync.LockArgs, err error) {
|
|
quorum, err := strconv.Atoi(r.URL.Query().Get(lockRESTQuorum))
|
|
if err != nil {
|
|
return args, err
|
|
}
|
|
|
|
args = dsync.LockArgs{
|
|
Owner: r.URL.Query().Get(lockRESTOwner),
|
|
UID: r.URL.Query().Get(lockRESTUID),
|
|
Source: r.URL.Query().Get(lockRESTSource),
|
|
Quorum: quorum,
|
|
}
|
|
|
|
var resources []string
|
|
bio := bufio.NewScanner(r.Body)
|
|
for bio.Scan() {
|
|
resources = append(resources, bio.Text())
|
|
}
|
|
|
|
if err := bio.Err(); err != nil {
|
|
return args, err
|
|
}
|
|
|
|
sort.Strings(resources)
|
|
args.Resources = resources
|
|
return args, nil
|
|
}
|
|
|
|
// HealthHandler returns success if request is authenticated.
|
|
func (l *lockRESTServer) HealthHandler(w http.ResponseWriter, r *http.Request) {
|
|
l.IsValid(w, r)
|
|
}
|
|
|
|
// LockHandler - Acquires a lock.
|
|
func (l *lockRESTServer) LockHandler(w http.ResponseWriter, r *http.Request) {
|
|
if !l.IsValid(w, r) {
|
|
l.writeErrorResponse(w, errors.New("invalid request"))
|
|
return
|
|
}
|
|
|
|
args, err := getLockArgs(r)
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
|
|
success, err := l.ll.Lock(r.Context(), args)
|
|
if err == nil && !success {
|
|
err = errLockConflict
|
|
}
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
}
|
|
|
|
// UnlockHandler - releases the acquired lock.
|
|
func (l *lockRESTServer) UnlockHandler(w http.ResponseWriter, r *http.Request) {
|
|
if !l.IsValid(w, r) {
|
|
l.writeErrorResponse(w, errors.New("invalid request"))
|
|
return
|
|
}
|
|
|
|
args, err := getLockArgs(r)
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
|
|
_, err = l.ll.Unlock(args)
|
|
// Ignore the Unlock() "reply" return value because if err == nil, "reply" is always true
|
|
// Consequently, if err != nil, reply is always false
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
}
|
|
|
|
// LockHandler - Acquires an RLock.
|
|
func (l *lockRESTServer) RLockHandler(w http.ResponseWriter, r *http.Request) {
|
|
if !l.IsValid(w, r) {
|
|
l.writeErrorResponse(w, errors.New("invalid request"))
|
|
return
|
|
}
|
|
|
|
args, err := getLockArgs(r)
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
|
|
success, err := l.ll.RLock(r.Context(), args)
|
|
if err == nil && !success {
|
|
err = errLockConflict
|
|
}
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
}
|
|
|
|
// RUnlockHandler - releases the acquired read lock.
|
|
func (l *lockRESTServer) RUnlockHandler(w http.ResponseWriter, r *http.Request) {
|
|
if !l.IsValid(w, r) {
|
|
l.writeErrorResponse(w, errors.New("invalid request"))
|
|
return
|
|
}
|
|
|
|
args, err := getLockArgs(r)
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
|
|
// Ignore the RUnlock() "reply" return value because if err == nil, "reply" is always true.
|
|
// Consequently, if err != nil, reply is always false
|
|
if _, err = l.ll.RUnlock(args); err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
}
|
|
|
|
// ForceUnlockHandler - query expired lock status.
|
|
func (l *lockRESTServer) ForceUnlockHandler(w http.ResponseWriter, r *http.Request) {
|
|
if !l.IsValid(w, r) {
|
|
l.writeErrorResponse(w, errors.New("invalid request"))
|
|
return
|
|
}
|
|
|
|
args, err := getLockArgs(r)
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
|
|
if _, err = l.ll.ForceUnlock(r.Context(), args); err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
}
|
|
|
|
// ExpiredHandler - query expired lock status.
|
|
func (l *lockRESTServer) ExpiredHandler(w http.ResponseWriter, r *http.Request) {
|
|
if !l.IsValid(w, r) {
|
|
l.writeErrorResponse(w, errors.New("invalid request"))
|
|
return
|
|
}
|
|
|
|
args, err := getLockArgs(r)
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
|
|
expired, err := l.ll.Expired(r.Context(), args)
|
|
if err != nil {
|
|
l.writeErrorResponse(w, err)
|
|
return
|
|
}
|
|
if !expired {
|
|
l.writeErrorResponse(w, errLockNotExpired)
|
|
return
|
|
}
|
|
}
|
|
|
|
// getLongLivedLocks returns locks that are older than a certain time and
|
|
// have not been 'checked' for validity too soon enough
|
|
func getLongLivedLocks(interval time.Duration) []lockRequesterInfo {
|
|
lrips := []lockRequesterInfo{}
|
|
globalLockServer.mutex.Lock()
|
|
for _, lriArray := range globalLockServer.lockMap {
|
|
for idx := range lriArray {
|
|
// Check whether enough time has gone by since last check
|
|
if time.Since(lriArray[idx].TimeLastCheck) >= interval {
|
|
lrips = append(lrips, lriArray[idx])
|
|
lriArray[idx].TimeLastCheck = UTCNow()
|
|
}
|
|
}
|
|
}
|
|
globalLockServer.mutex.Unlock()
|
|
return lrips
|
|
}
|
|
|
|
// lockMaintenance loops over locks that have been active for some time and checks back
|
|
// with the original server whether it is still alive or not
|
|
//
|
|
// Following logic inside ignores the errors generated for Dsync.Active operation.
|
|
// - server at client down
|
|
// - some network error (and server is up normally)
|
|
//
|
|
// We will ignore the error, and we will retry later to get a resolve on this lock
|
|
func lockMaintenance(ctx context.Context, interval time.Duration) {
|
|
objAPI := newObjectLayerFn()
|
|
if objAPI == nil {
|
|
return
|
|
}
|
|
|
|
z, ok := objAPI.(*erasureServerPools)
|
|
if !ok {
|
|
return
|
|
}
|
|
|
|
type nlock struct {
|
|
locks int
|
|
writer bool
|
|
}
|
|
|
|
updateNlocks := func(nlripsMap map[string]nlock, name string, writer bool) {
|
|
nlk, ok := nlripsMap[name]
|
|
if ok {
|
|
nlk.locks++
|
|
nlripsMap[name] = nlk
|
|
} else {
|
|
nlripsMap[name] = nlock{
|
|
locks: 1,
|
|
writer: writer,
|
|
}
|
|
}
|
|
}
|
|
|
|
// Validate if long lived locks are indeed clean.
|
|
// Get list of long lived locks to check for staleness.
|
|
lrips := getLongLivedLocks(interval)
|
|
lripsMap := make(map[string]nlock, len(lrips))
|
|
var mutex sync.Mutex // mutex for lripsMap updates
|
|
for _, lrip := range lrips {
|
|
// fetch the lockers participated in handing
|
|
// out locks for `nlrip.name`
|
|
var lockers []dsync.NetLocker
|
|
if lrip.Group {
|
|
lockers, _ = z.serverPools[0].getHashedSet("").getLockers()
|
|
} else {
|
|
_, objName := path2BucketObject(lrip.Name)
|
|
lockers, _ = z.serverPools[0].getHashedSet(objName).getLockers()
|
|
}
|
|
var wg sync.WaitGroup
|
|
wg.Add(len(lockers))
|
|
for _, c := range lockers {
|
|
go func(lrip lockRequesterInfo, c dsync.NetLocker) {
|
|
defer wg.Done()
|
|
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
|
|
|
|
// Call back to all participating servers, verify
|
|
// if each of those servers think lock is still
|
|
// active, if not expire it.
|
|
expired, err := c.Expired(ctx, dsync.LockArgs{
|
|
Owner: lrip.Owner,
|
|
UID: lrip.UID,
|
|
Resources: []string{lrip.Name},
|
|
})
|
|
cancel()
|
|
|
|
if err != nil {
|
|
mutex.Lock()
|
|
updateNlocks(lripsMap, lrip.Name, lrip.Writer)
|
|
mutex.Unlock()
|
|
return
|
|
}
|
|
|
|
if !expired {
|
|
mutex.Lock()
|
|
updateNlocks(lripsMap, lrip.Name, lrip.Writer)
|
|
mutex.Unlock()
|
|
}
|
|
}(lrip, c)
|
|
}
|
|
wg.Wait()
|
|
|
|
// less than the quorum, we have locks expired.
|
|
if lripsMap[lrip.Name].locks < lrip.Quorum {
|
|
// Purge the stale entry if it exists.
|
|
globalLockServer.removeEntryIfExists(lrip)
|
|
}
|
|
}
|
|
}
|
|
|
|
// Start lock maintenance from all lock servers.
|
|
func startLockMaintenance(ctx context.Context) {
|
|
// Wait until the object API is ready
|
|
// no need to start the lock maintenance
|
|
// if ObjectAPI is not initialized.
|
|
for {
|
|
objAPI := newObjectLayerFn()
|
|
if objAPI == nil {
|
|
time.Sleep(time.Second)
|
|
continue
|
|
}
|
|
break
|
|
}
|
|
|
|
// Initialize a new ticker with 1 minute between each ticks.
|
|
lkTimer := time.NewTimer(lockMaintenanceInterval)
|
|
// Stop the timer upon returning.
|
|
defer lkTimer.Stop()
|
|
|
|
r := rand.New(rand.NewSource(UTCNow().UnixNano()))
|
|
|
|
// Start with random sleep time, so as to avoid
|
|
// "synchronous checks" between servers
|
|
time.Sleep(time.Duration(r.Float64() * float64(lockMaintenanceInterval)))
|
|
|
|
for {
|
|
// Verifies every minute for locks held more than 2 minutes.
|
|
select {
|
|
case <-ctx.Done():
|
|
return
|
|
case <-lkTimer.C:
|
|
// Reset the timer for next cycle.
|
|
lkTimer.Reset(time.Duration(r.Float64() * float64(lockMaintenanceInterval)))
|
|
|
|
lockMaintenance(ctx, lockValidityCheckInterval)
|
|
}
|
|
}
|
|
}
|
|
|
|
// registerLockRESTHandlers - register lock rest router.
|
|
func registerLockRESTHandlers(router *mux.Router) {
|
|
lockServer := &lockRESTServer{
|
|
ll: newLocker(),
|
|
}
|
|
|
|
subrouter := router.PathPrefix(lockRESTPrefix).Subrouter()
|
|
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodHealth).HandlerFunc(httpTraceHdrs(lockServer.HealthHandler))
|
|
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodLock).HandlerFunc(httpTraceHdrs(lockServer.LockHandler))
|
|
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodRLock).HandlerFunc(httpTraceHdrs(lockServer.RLockHandler))
|
|
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodUnlock).HandlerFunc(httpTraceHdrs(lockServer.UnlockHandler))
|
|
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodRUnlock).HandlerFunc(httpTraceHdrs(lockServer.RUnlockHandler))
|
|
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodExpired).HandlerFunc(httpTraceAll(lockServer.ExpiredHandler))
|
|
subrouter.Methods(http.MethodPost).Path(lockRESTVersionPrefix + lockRESTMethodForceUnlock).HandlerFunc(httpTraceAll(lockServer.ForceUnlockHandler))
|
|
|
|
globalLockServer = lockServer.ll
|
|
|
|
go startLockMaintenance(GlobalContext)
|
|
}
|