dbg_eba("erase LEB %d:%d, PEB %d", vol_id, lnum, pnum);
 
+       down_read(&ubi->fm_sem);
        vol->eba_tbl[lnum] = UBI_LEB_UNMAPPED;
+       up_read(&ubi->fm_sem);
        err = ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 0);
 
 out_unlock:
        mutex_unlock(&ubi->buf_mutex);
        ubi_free_vid_hdr(ubi, vid_hdr);
 
+       down_read(&ubi->fm_sem);
        vol->eba_tbl[lnum] = new_pnum;
+       up_read(&ubi->fm_sem);
        ubi_wl_put_peb(ubi, vol_id, lnum, pnum, 1);
 
        ubi_msg("data was successfully recovered");
                }
        }
 
+       down_read(&ubi->fm_sem);
        vol->eba_tbl[lnum] = pnum;
+       up_read(&ubi->fm_sem);
 
        leb_write_unlock(ubi, vol_id, lnum);
        ubi_free_vid_hdr(ubi, vid_hdr);
        }
 
        ubi_assert(vol->eba_tbl[lnum] < 0);
+       down_read(&ubi->fm_sem);
        vol->eba_tbl[lnum] = pnum;
+       up_read(&ubi->fm_sem);
 
        leb_write_unlock(ubi, vol_id, lnum);
        ubi_free_vid_hdr(ubi, vid_hdr);
                        goto out_leb_unlock;
        }
 
+       down_read(&ubi->fm_sem);
        vol->eba_tbl[lnum] = pnum;
+       up_read(&ubi->fm_sem);
 
 out_leb_unlock:
        leb_write_unlock(ubi, vol_id, lnum);
        }
 
        ubi_assert(vol->eba_tbl[lnum] == from);
+       down_read(&ubi->fm_sem);
        vol->eba_tbl[lnum] = to;
+       up_read(&ubi->fm_sem);
 
 out_unlock_buf:
        mutex_unlock(&ubi->buf_mutex);