if rw.Lock then no need for nested rw.RLock

cmd/server/db.go

@@ -14,16 +14,19 @@ type DB struct {
 	scheme string
 	conn   string
 	rw     *sync.RWMutex
+	locked *bool
 }
 
 func NewDB(ctx context.Context, scheme, conn string) (DB, error) {
 	ctx, can := context.WithTimeout(ctx, time.Second*10)
 	defer can()
 
+	locked := false
 	db := DB{
 		scheme: scheme,
 		conn:   conn,
 		rw:     &sync.RWMutex{},
+		locked: &locked,
 	}
 
 	sql, err := db.dial(ctx)
@@ -38,12 +41,18 @@ func NewDB(ctx context.Context, scheme, conn string) (DB, error) {
 func (db DB) WithLock(cb func() error) error {
 	db.rw.Lock()
 	defer db.rw.Unlock()
+	*db.locked = true
+	defer func() {
+		*db.locked = false
+	}()
 	return cb()
 }
 
 func (db DB) Exec(ctx context.Context, q string, args ...any) error {
+	if !*db.locked {
 		db.rw.RLock()
 		defer db.rw.RUnlock()
+	}
 	return db.exec(ctx, q, args...)
 }
 
@@ -59,8 +68,10 @@ func (db DB) exec(ctx context.Context, q string, args ...any) error {
 }
 
 func (db DB) Query(ctx context.Context, cb func(*sql.Rows) error, q string, args ...any) error {
+	if !*db.locked {
 		db.rw.RLock()
 		defer db.rw.RUnlock()
+	}
 	return db.query(ctx, cb, q, args...)
 }