Make ReqInfo concurrency safe (#15204)

Some read/writes of ReqInfo did not get appropriate locks, leading to races.

Make sure reading and writing holds appropriate locks.

internal/logger/audit.go

@@ -149,7 +149,6 @@ func GetAuditEntry(ctx context.Context) *audit.Entry {
 			DeploymentID: xhttp.GlobalDeploymentID,
 			Time:         time.Now().UTC(),
 		}
-		SetAuditEntry(ctx, r)
 		return r
 	}
 	return nil
@@ -168,6 +167,8 @@ func AuditLog(ctx context.Context, w http.ResponseWriter, r *http.Request, reqCl
 		if reqInfo == nil {
 			return
 		}
+		reqInfo.RLock()
+		defer reqInfo.RUnlock()
 
 		entry = audit.ToEntry(w, r, reqClaims, xhttp.GlobalDeploymentID)
 		// indicates all requests for this API call are inbound

internal/logger/logger.go

@@ -290,6 +290,8 @@ func errToEntry(ctx context.Context, err error, errKind ...interface{}) log.Entr
 	if req == nil {
 		req = &ReqInfo{API: "SYSTEM"}
 	}
+	req.RLock()
+	defer req.RUnlock()
 
 	API := "SYSTEM"
 	if req.API != "" {

internal/logger/reqinfo.go

@@ -41,6 +41,7 @@ type ObjectVersion struct {
 }
 
 // ReqInfo stores the request info.
+// Reading/writing directly to struct requires appropriate R/W lock.
 type ReqInfo struct {
 	RemoteHost   string          // Client Host/IP
 	Host         string          // Node Host/IP
@@ -111,7 +112,7 @@ func (r *ReqInfo) GetTags() []KeyVal {
 	}
 	r.RLock()
 	defer r.RUnlock()
-	return append([]KeyVal(nil), r.tags...)
+	return append(make([]KeyVal, 0, len(r.tags)), r.tags...)
 }
 
 // GetTagsMap - returns the user defined tags in a map structure
@@ -145,7 +146,6 @@ func GetReqInfo(ctx context.Context) *ReqInfo {
 			return r
 		}
 		r = &ReqInfo{}
-		SetReqInfo(ctx, r)
 		return r
 	}
 	return nil