1 files changed, 75 insertions, 0 deletions
diff --git a/tests/cp/nfs-removal-race.sh b/tests/cp/nfs-removal-race.sh
new file mode 100755
index 0000000..e8e9710
--- /dev/null
+++ b/tests/cp/nfs-removal-race.sh
@@ -0,0 +1,75 @@
+#!/bin/sh
+# 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) 2012-2018 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