Fix transfer size if offset + size ends in block boundary

src/client/rpc/forward_data.cpp

@@ -132,7 +132,8 @@ forward_write(const string& path, const void* buf, const bool append_flag,
         }
 
         // receiver of last chunk must subtract
-        if(target == chnk_end_target) {
+        if(target == chnk_end_target &&
+           !is_divisible(offset + write_size, gkfs::config::rpc::chunksize)) {
             total_chunk_size -= block_underrun(offset + write_size,
                                                gkfs::config::rpc::chunksize);
         }
@@ -309,7 +310,8 @@ forward_read(const string& path, void* buf, const off64_t offset,
         }
 
         // receiver of last chunk must subtract
-        if(target == chnk_end_target) {
+        if(target == chnk_end_target &&
+           !is_divisible(offset + read_size, gkfs::config::rpc::chunksize)) {
             total_chunk_size -= block_underrun(offset + read_size,
                                                gkfs::config::rpc::chunksize);
         }