feat(quark): shard request file (close #4175)

server/webdav/webdav.go

@@ -21,6 +21,7 @@ import (
 	"github.com/alist-org/alist/v3/internal/sign"
 	"github.com/alist-org/alist/v3/pkg/utils"
 	"github.com/alist-org/alist/v3/server/common"
+	log "github.com/sirupsen/logrus"
 )
 
 type Handler struct {
@@ -237,6 +238,7 @@ func (h *Handler) handleGetHeadPost(w http.ResponseWriter, r *http.Request) (sta
 		}
 		err = common.Proxy(w, r, link, fi)
 		if err != nil {
+			log.Errorf("webdav proxy error: %+v", err)
 			return http.StatusInternalServerError, err
 		}
 	} else if storage.GetStorage().WebdavProxy() && downProxyUrl != "" {