fix: improve mount quota enforcement to prevent overflow (#7804)

* fix: improve mount quota enforcement to prevent overflow (fixes seaweedfs-csi-driver#218)

* test: add unit tests for quota enforcement

weed/mount/weedfs_file_mkrm.go

@@ -37,7 +37,7 @@ func (wfs *WFS) Create(cancel <-chan struct{}, in *fuse.CreateIn, name string, o
  */
 func (wfs *WFS) Mknod(cancel <-chan struct{}, in *fuse.MknodIn, name string, out *fuse.EntryOut) (code fuse.Status) {
 
-	if wfs.IsOverQuota {
+	if wfs.IsOverQuotaWithUncommitted() {
 		return fuse.Status(syscall.ENOSPC)
 	}