util: Add IOCtxLock interface

that abstracts rados Ioctx Lock/Unlocks

Signed-off-by: Niraj Yadav <[email protected]>

internal/util/lock/lock.go

@@ -0,0 +1,108 @@
+/*
+Copyright 2024 The Ceph-CSI Authors.
+
+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 lock
+
+import (
+	"context"
+	"fmt"
+	"syscall"
+	"time"
+
+	"github.com/ceph/go-ceph/rados"
+
+	"github.com/ceph/ceph-csi/internal/util/log"
+)
+
+// IOCtxLock provides methods for acquiring and releasing exclusive locks on a volume.
+// using rados IO context locks.
+type IOCtxLock interface {
+	LockExclusive(ctx context.Context) error
+	Unlock(ctx context.Context)
+}
+
+type lock struct {
+	volID      string
+	lockName   string
+	lockDesc   string
+	lockCookie string
+	timeout    time.Duration
+	ioctx      *rados.IOContext
+}
+
+// NewLock returns `lock` type that implements the IOCtxLock interface.
+func NewLock(
+	ioctx *rados.IOContext,
+	volID string,
+	lockName string,
+	lockCookie string,
+	lockDesc string,
+	timeout time.Duration,
+) IOCtxLock {
+	return &lock{
+		volID:      volID,
+		lockName:   lockName,
+		lockDesc:   lockDesc,
+		lockCookie: lockCookie,
+		timeout:    timeout,
+		ioctx:      ioctx,
+	}
+}
+
+// LockExclusive acquires an exclusive lock on the volume identified by
+// the name and cookie pair.
+func (lck *lock) LockExclusive(ctx context.Context) error {
+	var flags byte = 0
+	ret, err := lck.ioctx.LockExclusive(
+		lck.volID,
+		lck.lockName,
+		lck.lockCookie,
+		lck.lockDesc,
+		lck.timeout,
+		&flags)
+
+	if ret != 0 {
+		switch ret {
+		case -int(syscall.EBUSY):
+			return fmt.Errorf("lock is already held by another client and cookie pair for %v volume",
+				lck.volID)
+		case -int(syscall.EEXIST):
+			return fmt.Errorf("lock is already held by the same client and cookie pair for %v volume",
+				lck.volID)
+		default:
+			return fmt.Errorf("failed to lock volume ID %v: %w", lck.volID, err)
+		}
+	}
+
+	return nil
+}
+
+// Unlock releases the exclusive lock on the volume.
+func (lck *lock) Unlock(ctx context.Context) {
+	ret, err := lck.ioctx.Unlock(lck.volID, lck.lockName, lck.lockCookie)
+
+	switch ret {
+	case 0:
+		log.DebugLog(ctx, "lock %s for vol id %s successfully released ",
+			lck.lockName, lck.volID)
+	case -int(syscall.ENOENT):
+		log.DebugLog(ctx, "lock is not held by the specified %s, %s pair",
+			lck.lockCookie, lck.lockName)
+	default:
+		log.ErrorLog(ctx, "failed to release lock %s: %v",
+			lck.lockName, err)
+	}
+}