mirror of
https://github.com/minio/minio.git
synced 2024-12-25 22:55:54 -05:00
405 lines
10 KiB
Go
405 lines
10 KiB
Go
// Copyright (c) 2015-2021 MinIO, Inc.
|
|
//
|
|
// This file is part of MinIO Object Storage stack
|
|
//
|
|
// This program is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Affero General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Affero General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Affero General Public License
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package cmd
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
"strconv"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/minio/minio/internal/dsync"
|
|
)
|
|
|
|
// lockRequesterInfo stores various info from the client for each lock that is requested.
|
|
type lockRequesterInfo struct {
|
|
Name string // name of the resource lock was requested for
|
|
Writer bool // Bool whether write or read lock.
|
|
UID string // UID to uniquely identify request of client.
|
|
Timestamp time.Time // Timestamp set at the time of initialization.
|
|
TimeLastRefresh time.Time // Timestamp for last lock refresh.
|
|
Source string // Contains line, function and filename reqesting the lock.
|
|
Group bool // indicates if it was a group lock.
|
|
// Owner represents the UUID of the owner who originally requested the lock
|
|
// useful in expiry.
|
|
Owner string
|
|
// Quorum represents the quorum required for this lock to be active.
|
|
Quorum int
|
|
idx int
|
|
}
|
|
|
|
// isWriteLock returns whether the lock is a write or read lock.
|
|
func isWriteLock(lri []lockRequesterInfo) bool {
|
|
return len(lri) == 1 && lri[0].Writer
|
|
}
|
|
|
|
// localLocker implements Dsync.NetLocker
|
|
type localLocker struct {
|
|
mutex sync.Mutex
|
|
lockMap map[string][]lockRequesterInfo
|
|
lockUID map[string]string // UUID -> resource map.
|
|
}
|
|
|
|
func (l *localLocker) String() string {
|
|
return globalEndpoints.Localhost()
|
|
}
|
|
|
|
func (l *localLocker) canTakeLock(resources ...string) bool {
|
|
for _, resource := range resources {
|
|
_, lockTaken := l.lockMap[resource]
|
|
if lockTaken {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func (l *localLocker) Lock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
|
|
if len(args.Resources) > maxDeleteList {
|
|
return false, fmt.Errorf("internal error: localLocker.Lock called with more than %d resources", maxDeleteList)
|
|
}
|
|
|
|
l.mutex.Lock()
|
|
defer l.mutex.Unlock()
|
|
|
|
if !l.canTakeLock(args.Resources...) {
|
|
// Not all locks can be taken on resources,
|
|
// reject it completely.
|
|
return false, nil
|
|
}
|
|
|
|
// No locks held on the all resources, so claim write
|
|
// lock on all resources at once.
|
|
for i, resource := range args.Resources {
|
|
l.lockMap[resource] = []lockRequesterInfo{
|
|
{
|
|
Name: resource,
|
|
Writer: true,
|
|
Source: args.Source,
|
|
Owner: args.Owner,
|
|
UID: args.UID,
|
|
Timestamp: UTCNow(),
|
|
TimeLastRefresh: UTCNow(),
|
|
Group: len(args.Resources) > 1,
|
|
Quorum: args.Quorum,
|
|
idx: i,
|
|
},
|
|
}
|
|
l.lockUID[formatUUID(args.UID, i)] = resource
|
|
}
|
|
return true, nil
|
|
}
|
|
|
|
func formatUUID(s string, idx int) string {
|
|
return s + strconv.Itoa(idx)
|
|
}
|
|
|
|
func (l *localLocker) Unlock(_ context.Context, args dsync.LockArgs) (reply bool, err error) {
|
|
if len(args.Resources) > maxDeleteList {
|
|
return false, fmt.Errorf("internal error: localLocker.Unlock called with more than %d resources", maxDeleteList)
|
|
}
|
|
|
|
l.mutex.Lock()
|
|
defer l.mutex.Unlock()
|
|
err = nil
|
|
|
|
for _, resource := range args.Resources {
|
|
lri, ok := l.lockMap[resource]
|
|
if ok && !isWriteLock(lri) {
|
|
// Unless it is a write lock reject it.
|
|
err = fmt.Errorf("unlock attempted on a read locked entity: %s", resource)
|
|
continue
|
|
}
|
|
if ok {
|
|
reply = l.removeEntry(resource, args, &lri) || reply
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
// removeEntry based on the uid of the lock message, removes a single entry from the
|
|
// lockRequesterInfo array or the whole array from the map (in case of a write lock
|
|
// or last read lock)
|
|
// UID and optionally owner must match for entries to be deleted.
|
|
func (l *localLocker) removeEntry(name string, args dsync.LockArgs, lri *[]lockRequesterInfo) bool {
|
|
// Find correct entry to remove based on uid.
|
|
for index, entry := range *lri {
|
|
if entry.UID == args.UID && (args.Owner == "" || entry.Owner == args.Owner) {
|
|
if len(*lri) == 1 {
|
|
// Remove the write lock.
|
|
delete(l.lockMap, name)
|
|
} else {
|
|
// Remove the appropriate read lock.
|
|
*lri = append((*lri)[:index], (*lri)[index+1:]...)
|
|
l.lockMap[name] = *lri
|
|
}
|
|
delete(l.lockUID, formatUUID(args.UID, entry.idx))
|
|
return true
|
|
}
|
|
}
|
|
|
|
// None found return false, perhaps entry removed in previous run.
|
|
return false
|
|
}
|
|
|
|
func (l *localLocker) RLock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
|
|
if len(args.Resources) > 1 {
|
|
return false, fmt.Errorf("internal error: localLocker.RLock called with more than one resource")
|
|
}
|
|
|
|
l.mutex.Lock()
|
|
defer l.mutex.Unlock()
|
|
resource := args.Resources[0]
|
|
lrInfo := lockRequesterInfo{
|
|
Name: resource,
|
|
Writer: false,
|
|
Source: args.Source,
|
|
Owner: args.Owner,
|
|
UID: args.UID,
|
|
Timestamp: UTCNow(),
|
|
TimeLastRefresh: UTCNow(),
|
|
Quorum: args.Quorum,
|
|
}
|
|
if lri, ok := l.lockMap[resource]; ok {
|
|
if reply = !isWriteLock(lri); reply {
|
|
// Unless there is a write lock
|
|
l.lockMap[resource] = append(l.lockMap[resource], lrInfo)
|
|
l.lockUID[formatUUID(args.UID, 0)] = resource
|
|
}
|
|
} else {
|
|
// No locks held on the given name, so claim (first) read lock
|
|
l.lockMap[resource] = []lockRequesterInfo{lrInfo}
|
|
l.lockUID[formatUUID(args.UID, 0)] = resource
|
|
reply = true
|
|
}
|
|
return reply, nil
|
|
}
|
|
|
|
func (l *localLocker) RUnlock(_ context.Context, args dsync.LockArgs) (reply bool, err error) {
|
|
if len(args.Resources) > 1 {
|
|
return false, fmt.Errorf("internal error: localLocker.RUnlock called with more than one resource")
|
|
}
|
|
|
|
l.mutex.Lock()
|
|
defer l.mutex.Unlock()
|
|
var lri []lockRequesterInfo
|
|
|
|
resource := args.Resources[0]
|
|
if lri, reply = l.lockMap[resource]; !reply {
|
|
// No lock is held on the given name
|
|
return true, nil
|
|
}
|
|
if isWriteLock(lri) {
|
|
// A write-lock is held, cannot release a read lock
|
|
return false, fmt.Errorf("RUnlock attempted on a write locked entity: %s", resource)
|
|
}
|
|
l.removeEntry(resource, args, &lri)
|
|
return reply, nil
|
|
}
|
|
|
|
type lockStats struct {
|
|
Total int
|
|
Writes int
|
|
Reads int
|
|
}
|
|
|
|
func (l *localLocker) stats() lockStats {
|
|
l.mutex.Lock()
|
|
defer l.mutex.Unlock()
|
|
|
|
st := lockStats{Total: len(l.lockMap)}
|
|
for _, v := range l.lockMap {
|
|
if len(v) == 0 {
|
|
continue
|
|
}
|
|
entry := v[0]
|
|
if entry.Writer {
|
|
st.Writes++
|
|
} else {
|
|
st.Reads += len(v)
|
|
}
|
|
}
|
|
return st
|
|
}
|
|
|
|
func (l *localLocker) DupLockMap() map[string][]lockRequesterInfo {
|
|
l.mutex.Lock()
|
|
defer l.mutex.Unlock()
|
|
|
|
lockCopy := make(map[string][]lockRequesterInfo, len(l.lockMap))
|
|
for k, v := range l.lockMap {
|
|
if len(v) == 0 {
|
|
delete(l.lockMap, k)
|
|
continue
|
|
}
|
|
lockCopy[k] = append(make([]lockRequesterInfo, 0, len(v)), v...)
|
|
}
|
|
return lockCopy
|
|
}
|
|
|
|
func (l *localLocker) Close() error {
|
|
return nil
|
|
}
|
|
|
|
// IsOnline - local locker is always online.
|
|
func (l *localLocker) IsOnline() bool {
|
|
return true
|
|
}
|
|
|
|
// IsLocal - local locker returns true.
|
|
func (l *localLocker) IsLocal() bool {
|
|
return true
|
|
}
|
|
|
|
func (l *localLocker) ForceUnlock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
|
|
select {
|
|
case <-ctx.Done():
|
|
return false, ctx.Err()
|
|
default:
|
|
l.mutex.Lock()
|
|
defer l.mutex.Unlock()
|
|
if len(args.UID) == 0 {
|
|
for _, resource := range args.Resources {
|
|
lris, ok := l.lockMap[resource]
|
|
if !ok {
|
|
continue
|
|
}
|
|
// Collect uids, so we don't mutate while we delete
|
|
uids := make([]string, 0, len(lris))
|
|
for _, lri := range lris {
|
|
uids = append(uids, lri.UID)
|
|
}
|
|
|
|
// Delete collected uids:
|
|
for _, uid := range uids {
|
|
lris, ok := l.lockMap[resource]
|
|
if !ok {
|
|
// Just to be safe, delete uuids.
|
|
for idx := 0; idx < maxDeleteList; idx++ {
|
|
mapID := formatUUID(uid, idx)
|
|
if _, ok := l.lockUID[mapID]; !ok {
|
|
break
|
|
}
|
|
delete(l.lockUID, mapID)
|
|
}
|
|
continue
|
|
}
|
|
l.removeEntry(resource, dsync.LockArgs{UID: uid}, &lris)
|
|
}
|
|
}
|
|
return true, nil
|
|
}
|
|
|
|
idx := 0
|
|
for {
|
|
mapID := formatUUID(args.UID, idx)
|
|
resource, ok := l.lockUID[mapID]
|
|
if !ok {
|
|
return idx > 0, nil
|
|
}
|
|
lris, ok := l.lockMap[resource]
|
|
if !ok {
|
|
// Unexpected inconsistency, delete.
|
|
delete(l.lockUID, mapID)
|
|
idx++
|
|
continue
|
|
}
|
|
reply = true
|
|
l.removeEntry(resource, dsync.LockArgs{UID: args.UID}, &lris)
|
|
idx++
|
|
}
|
|
}
|
|
}
|
|
|
|
func (l *localLocker) Refresh(ctx context.Context, args dsync.LockArgs) (refreshed bool, err error) {
|
|
select {
|
|
case <-ctx.Done():
|
|
return false, ctx.Err()
|
|
default:
|
|
l.mutex.Lock()
|
|
defer l.mutex.Unlock()
|
|
|
|
// Check whether uid is still active.
|
|
resource, ok := l.lockUID[formatUUID(args.UID, 0)]
|
|
if !ok {
|
|
return false, nil
|
|
}
|
|
idx := 0
|
|
for {
|
|
lris, ok := l.lockMap[resource]
|
|
if !ok {
|
|
// Inconsistent. Delete UID.
|
|
delete(l.lockUID, formatUUID(args.UID, idx))
|
|
return idx > 0, nil
|
|
}
|
|
for i := range lris {
|
|
if lris[i].UID == args.UID {
|
|
lris[i].TimeLastRefresh = UTCNow()
|
|
}
|
|
}
|
|
idx++
|
|
resource, ok = l.lockUID[formatUUID(args.UID, idx)]
|
|
if !ok {
|
|
// No more resources for UID, but we did update at least one.
|
|
return true, nil
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Similar to removeEntry but only removes an entry only if the lock entry exists in map.
|
|
// Caller must hold 'l.mutex' lock.
|
|
func (l *localLocker) expireOldLocks(interval time.Duration) {
|
|
l.mutex.Lock()
|
|
defer l.mutex.Unlock()
|
|
|
|
for k, lris := range l.lockMap {
|
|
modified := false
|
|
for i := 0; i < len(lris); {
|
|
lri := &lris[i]
|
|
if time.Since(lri.TimeLastRefresh) > interval {
|
|
delete(l.lockUID, formatUUID(lri.UID, lri.idx))
|
|
if len(lris) == 1 {
|
|
// Remove the write lock.
|
|
delete(l.lockMap, lri.Name)
|
|
modified = false
|
|
break
|
|
}
|
|
modified = true
|
|
// Remove the appropriate lock.
|
|
lris = append(lris[:i], lris[i+1:]...)
|
|
// Check same i
|
|
} else {
|
|
// Move to next
|
|
i++
|
|
}
|
|
}
|
|
if modified {
|
|
l.lockMap[k] = lris
|
|
}
|
|
}
|
|
}
|
|
|
|
func newLocker() *localLocker {
|
|
return &localLocker{
|
|
lockMap: make(map[string][]lockRequesterInfo, 1000),
|
|
lockUID: make(map[string]string, 1000),
|
|
}
|
|
}
|