Prepare for radical source tree reorganization.zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 318 insertions, 0 deletions

diff --git a/REORG.TODO/io/tst-open-tmpfile.c b/REORG.TODO/io/tst-open-tmpfile.c
new file mode 100644
index 0000000000..485109706f
--- /dev/null
+++ b/REORG.TODO/io/tst-open-tmpfile.c
@@ -0,0 +1,318 @@
+/* Test open and openat with O_TMPFILE.
+   Copyright (C) 2016-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This test verifies that open and openat work as expected, i.e. they
+   create a deleted file with the requested file mode.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <support/support.h>
+
+#ifdef O_TMPFILE
+typedef int (*wrapper_func) (const char *, int, mode_t);
+
+/* Error-checking wrapper for the open function, compatible with the
+   wrapper_func type.  */
+static int
+wrap_open (const char *path, int flags, mode_t mode)
+{
+  int ret = open (path, flags, mode);
+  if (ret < 0)
+    {
+      printf ("error: open (\"%s\", 0x%x, 0%03o): %m\n", path, flags, mode);
+      exit (1);
+    }
+  return ret;
+}
+
+/* Error-checking wrapper for the openat function, compatible with the
+   wrapper_func type.  */
+static int
+wrap_openat (const char *path, int flags, mode_t mode)
+{
+  int ret = openat (AT_FDCWD, path, flags, mode);
+  if (ret < 0)
+    {
+      printf ("error: openat (\"%s\", 0x%x, 0%03o): %m\n", path, flags, mode);
+      exit (1);
+    }
+  return ret;
+}
+
+/* Error-checking wrapper for the open64 function, compatible with the
+   wrapper_func type.  */
+static int
+wrap_open64 (const char *path, int flags, mode_t mode)
+{
+  int ret = open64 (path, flags, mode);
+  if (ret < 0)
+    {
+      printf ("error: open64 (\"%s\", 0x%x, 0%03o): %m\n", path, flags, mode);
+      exit (1);
+    }
+  return ret;
+}
+
+/* Error-checking wrapper for the openat64 function, compatible with the
+   wrapper_func type.  */
+static int
+wrap_openat64 (const char *path, int flags, mode_t mode)
+{
+  int ret = openat64 (AT_FDCWD, path, flags, mode);
+  if (ret < 0)
+    {
+      printf ("error: openat64 (\"%s\", 0x%x, 0%03o): %m\n", path, flags, mode);
+      exit (1);
+    }
+  return ret;
+}
+
+/* Return true if FD is flagged as deleted in /proc/self/fd, false if
+   not.  */
+static bool
+is_file_deteted (int fd)
+{
+  char *proc_fd_path = xasprintf ("/proc/self/fd/%d", fd);
+  char file_path[4096];
+  ssize_t file_path_length
+    = readlink (proc_fd_path, file_path, sizeof (file_path));
+  if (file_path_length < 0)
+    {
+      printf ("error: readlink (\"%s\"): %m", proc_fd_path);
+      free (proc_fd_path);
+      exit (1);
+    }
+  free (proc_fd_path);
+  if (file_path_length == sizeof (file_path))
+    {
+      printf ("error: path in /proc resolves to overlong file name: %.*s\n",
+              (int) file_path_length, file_path);
+      exit (1);
+    }
+  const char *deleted = " (deleted)";
+  if (file_path_length < strlen (deleted))
+    {
+      printf ("error: path in /proc is too short: %.*s\n",
+              (int) file_path_length, file_path);
+      exit (1);
+    }
+  return memcmp (file_path + file_path_length - strlen (deleted),
+              deleted, strlen (deleted)) == 0;
+}
+
+/* Obtain a file name which is difficult to guess.  */
+static char *
+get_random_name (void)
+{
+  unsigned long long bytes[2];
+  int random_device = open ("/dev/urandom", O_RDONLY);
+  if (random_device < 0)
+    {
+      printf ("error: open (\"/dev/urandom\"): %m\n");
+      exit (1);
+    }
+  ssize_t ret = read (random_device, bytes, sizeof (bytes));
+  if (ret < 0)
+    {
+      printf ("error: read (\"/dev/urandom\"): %m\n");
+      exit (1);
+    }
+  if (ret != sizeof (bytes))
+    {
+      printf ("error: short read from /dev/urandom: %zd\n", ret);
+      exit (1);
+    }
+  close (random_device);
+  return xasprintf ("tst-open-tmpfile-%08llx%08llx.tmp", bytes[0], bytes[1]);
+}
+
+/* Check open/openat (as specified by OP and WRAPPER) with a specific
+   PATH/FLAGS/MODE combination.  */
+static void
+check_wrapper_flags_mode (const char *op, wrapper_func wrapper,
+                          const char *path, int flags, mode_t mode)
+{
+  int fd = wrapper (path, flags | O_TMPFILE, mode);
+  struct stat64 st;
+  if (fstat64 (fd, &st) != 0)
+    {
+      printf ("error: fstat64: %m\n");
+      exit (1);
+    }
+
+  /* Verify that the mode was correctly processed.  */
+  int actual_mode = st.st_mode & 0777;
+  if (actual_mode != mode)
+    {
+      printf ("error: unexpected mode; expected 0%03o, actual 0%03o\n",
+              mode, actual_mode);
+      exit (1);
+    }
+
+  /* Check that the file is marked as deleted in /proc.  */
+  if (!is_file_deteted (fd))
+    {
+      printf ("error: path in /proc is not marked as deleted\n");
+      exit (1);
+    }
+
+  /* Check that the file can be turned into a regular file with
+     linkat.  Open a file descriptor for the directory at PATH.  Use
+     AT_FDCWD if PATH is ".", to exercise that functionality as
+     well.  */
+  int path_fd;
+  if (strcmp (path, ".") == 0)
+    path_fd = AT_FDCWD;
+  else
+    {
+      path_fd = open (path, O_RDONLY | O_DIRECTORY);
+      if (path_fd < 0)
+        {
+          printf ("error: open (\"%s\"): %m\n", path);
+          exit (1);
+        }
+    }
+
+  /* Use a hard-to-guess name for the new directory entry.  */
+  char *new_name = get_random_name ();
+
+  /* linkat does not require privileges if the path in /proc/self/fd
+     is used.  */
+  char *proc_fd_path = xasprintf ("/proc/self/fd/%d", fd);
+  if (linkat (AT_FDCWD, proc_fd_path, path_fd, new_name,
+              AT_SYMLINK_FOLLOW) == 0)
+    {
+      if (unlinkat (path_fd, new_name, 0) != 0 && errno != ENOENT)
+        {
+          printf ("error: unlinkat (\"%s/%s\"): %m\n", path, new_name);
+          exit (1);
+        }
+    }
+  else
+    {
+      /* linkat failed.  This is expected if O_EXCL was specified.  */
+      if ((flags & O_EXCL) == 0)
+        {
+          printf ("error: linkat failed after %s (\"%s\", 0x%x, 0%03o): %m\n",
+                  op, path, flags, mode);
+          exit (1);
+        }
+    }
+
+  free (proc_fd_path);
+  free (new_name);
+  if (path_fd != AT_FDCWD)
+    close (path_fd);
+  close (fd);
+}
+
+/* Check OP/WRAPPER with various flags at a specific PATH and
+   MODE.  */
+static void
+check_wrapper_mode (const char *op, wrapper_func wrapper,
+                    const char *path, mode_t mode)
+{
+  check_wrapper_flags_mode (op, wrapper, path, O_WRONLY, mode);
+  check_wrapper_flags_mode (op, wrapper, path, O_WRONLY | O_EXCL, mode);
+  check_wrapper_flags_mode (op, wrapper, path, O_RDWR, mode);
+  check_wrapper_flags_mode (op, wrapper, path, O_RDWR | O_EXCL, mode);
+}
+
+/* Check open/openat with varying permissions.  */
+static void
+check_wrapper (const char *op, wrapper_func wrapper,
+                    const char *path)
+{
+  printf ("info: testing %s at: %s\n", op, path);
+  check_wrapper_mode (op, wrapper, path, 0);
+  check_wrapper_mode (op, wrapper, path, 0640);
+  check_wrapper_mode (op, wrapper, path, 0600);
+  check_wrapper_mode (op, wrapper, path, 0755);
+  check_wrapper_mode (op, wrapper, path, 0750);
+}
+
+/* Verify that the directory at PATH supports O_TMPFILE.  Exit with
+   status 77 (unsupported) if the kernel does not support O_TMPFILE.
+   Even with kernel support, not all file systems O_TMPFILE, so return
+   true if the directory supports O_TMPFILE, false if not.  */
+static bool
+probe_path (const char *path)
+{
+  int fd = openat (AT_FDCWD, path, O_TMPFILE | O_RDWR, 0);
+  if (fd < 0)
+    {
+      if (errno == EISDIR)
+        /* The system does not support O_TMPFILE.  */
+        {
+          printf ("info: kernel does not support O_TMPFILE\n");
+          exit (77);
+        }
+      if (errno == EOPNOTSUPP)
+        {
+          printf ("info: path does not support O_TMPFILE: %s\n", path);
+          return false;
+        }
+      printf ("error: openat (\"%s\", O_TMPFILE | O_RDWR): %m\n", path);
+      exit (1);
+    }
+  close (fd);
+  return true;
+}
+
+static int
+do_test (void)
+{
+  umask (0);
+  const char *paths[] = { ".", "/dev/shm", "/tmp",
+                          getenv ("TEST_TMPFILE_PATH"),
+                          NULL };
+  bool supported = false;
+  for (int i = 0; paths[i] != NULL; ++i)
+    if (probe_path (paths[i]))
+      {
+        supported = true;
+        check_wrapper ("open", wrap_open, paths[i]);
+        check_wrapper ("openat", wrap_openat, paths[i]);
+        check_wrapper ("open64", wrap_open64, paths[i]);
+        check_wrapper ("openat64", wrap_openat64, paths[i]);
+      }
+
+  if (!supported)
+    return 77;
+
+  return 0;
+}
+
+#else  /* !O_TMPFILE */
+
+static int
+do_test (void)
+{
+  return 77;
+}
+
+#endif  /* O_TMPFILE */
+
+#include <support/test-driver.c>