| # Running cp S D on an NFS client while another client has just removed D | |
| # would lead (w/coreutils-8.16 and earlier) to cp's initial stat call | |
| # seeing (via stale NFS cache) that D exists, so that cp would then call | |
| # open without the O_CREAT flag. Yet, the open must actually consult | |
| # the server, which confesses that D has been deleted, thus causing the | |
| # open call to fail with ENOENT. | |
| # | |
| # This test simulates that situation by intercepting stat for a nonexistent | |
| # destination, D, and making the stat fill in the result struct for another | |
| # file and return 0. | |
| # | |
| # This test is skipped on systems that lack LD_PRELOAD support; that's fine. | |
| # Similarly, on a system that lacks <dlfcn.h> or __xstat, skipping it is fine. | |
| # Copyright (C) 2012-2025 Free Software Foundation, Inc. | |
| # This program is free software: you can redistribute it and/or modify | |
| # it under the terms of the GNU General Public License as published by | |
| # the Free Software Foundation, either version 3 of the License, or | |
| # (at your option) any later version. | |
| # This program is distributed in the hope that it will be useful, | |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| # GNU General Public License for more details. | |
| # You should have received a copy of the GNU General Public License | |
| # along with this program. If not, see <https://www.gnu.org/licenses/>. | |
| . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src | |
| print_ver_ cp | |
| require_gcc_shared_ | |
| # Replace each stat call with a call to this wrapper. | |
| cat > k.c <<'EOF' || framework_failure_ | |
| #define _GNU_SOURCE | |
| #include <stdio.h> | |
| #include <sys/types.h> | |
| #include <dlfcn.h> | |
| #define __xstat __xstat_orig | |
| #include <sys/stat.h> | |
| #include <stddef.h> | |
| #undef __xstat | |
| int | |
| __xstat (int ver, const char *path, struct stat *st) | |
| { | |
| static int (*real_stat)(int ver, const char *path, struct stat *st) = NULL; | |
| fclose(fopen("preloaded", "w")); | |
| if (!real_stat) | |
| real_stat = dlsym (RTLD_NEXT, "__xstat"); | |
| /* When asked to stat nonexistent "d", | |
| return results suggesting it exists. */ | |
| return real_stat (ver, *path == 'd' && path[1] == 0 ? "d2" : path, st); | |
| } | |
| EOF | |
| # Then compile/link it: | |
| gcc_shared_ k.c k.so \ | |
| || framework_failure_ 'failed to build shared library' | |
| touch d2 || framework_failure_ | |
| echo xyz > src || framework_failure_ | |
| # Finally, run the test: | |
| LD_PRELOAD=$LD_PRELOAD:./k.so cp src d || fail=1 | |
| test -f preloaded || skip_ 'LD_PRELOAD was ineffective?' | |
| compare src d || fail=1 | |
| Exit $fail | |