On Thu, Nov 05, 2020 at 10:58:26PM +0000, KP Singh wrote: > + > + ret = copy_file_range(fd_in, NULL, fd_out, NULL, stat.st_size, 0); centos7 glibc doesn't have it. /prog_tests/test_local_storage.c:59:8: warning: implicit declaration of function ‘copy_file_range’; did you mean ‘sync_file_range’? [-Wimplicit-function-declaration] 59 | ret = copy_file_range(fd_in, NULL, fd_out, NULL, stat.st_size, 0); | ^~~~~~~~~~~~~~~ | sync_file_range BINARY test_progs BINARY test_progs-no_alu32 ld: test_local_storage.test.o: in function `copy_rm': test_local_storage.c:59: undefined reference to `copy_file_range' Could you use something else or wrap it similar to pidfd_open ?