unix,fs: use utimes & friends for uv_fs_utime

This should improve uv_fs_utime resolution and reliability, as
utime(2)'s precision is left more to the implementing platform than the
newer but well supported alternatives.

Related to nodejs/node#22070

src/unix/fs.c

@@ -698,10 +698,94 @@ static ssize_t uv__fs_sendfile(uv_fs_t* req) {
 
 
 static ssize_t uv__fs_utime(uv_fs_t* req) {
-  struct utimbuf buf;
-  buf.actime = req->atime;
-  buf.modtime = req->mtime;
-  return utime(req->path, &buf); /* TODO use utimes() where available */
+#if defined(__linux__)
+  /* utimesat() has nanosecond resolution but we stick to microseconds
+   * for the sake of consistency with other platforms.
+   */
+  static int no_utimesat;
+  struct timespec ts[2];
+  struct timeval tv[2];
+  int r;
+
+  if (no_utimesat)
+    goto skip;
+
+  ts[0].tv_sec  = req->atime;
+  ts[0].tv_nsec = (uint64_t)(req->atime * 1000000) % 1000000 * 1000;
+  ts[1].tv_sec  = req->mtime;
+  ts[1].tv_nsec = (uint64_t)(req->mtime * 1000000) % 1000000 * 1000;
+
+  r = uv__utimesat(NULL, req->path, ts, 0);
+  if (r == 0)
+    return r;
+
+  if (errno != ENOSYS)
+    return r;
+
+  no_utimesat = 1;
+
+skip:
+
+  tv[0].tv_sec  = req->atime;
+  tv[0].tv_usec = (uint64_t)(req->atime * 1000000) % 1000000;
+  tv[1].tv_sec  = req->mtime;
+  tv[1].tv_usec = (uint64_t)(req->mtime * 1000000) % 1000000;
+  snprintf(req->path, sizeof(req->path));
+
+  r = utimes(req->path, tv);
+  if (r == 0)
+    return r;
+
+  switch (errno) {
+  case ENOENT:
+    // if (fcntl(req->file, F_GETFL) == -1 && errno == EBADF)
+      break;
+    /* Fall through. */
+
+  case EACCES:
+  case ENOTDIR:
+    errno = ENOSYS;
+    break;
+  }
+
+  return r;
+
+#elif defined(__APPLE__)                                                      \
+    || defined(__DragonFly__)                                                 \
+    || defined(__FreeBSD__)                                                   \
+    || defined(__FreeBSD_kernel__)                                            \
+    || defined(__NetBSD__)                                                    \
+    || defined(__OpenBSD__)                                                   \
+    || defined(__sun)
+  struct timeval tv[2];
+  tv[0].tv_sec  = req->atime;
+  tv[0].tv_usec = (uint64_t)(req->atime * 1000000) % 1000000;
+  tv[1].tv_sec  = req->mtime;
+  tv[1].tv_usec = (uint64_t)(req->mtime * 1000000) % 1000000;
+# if defined(__sun)
+  return utimesat(NULL, req->path, tv);
+# else
+  return utimes(req->path, tv);
+# endif
+#elif defined(_AIX71)
+  struct timespec ts[2];
+  ts[0].tv_sec  = req->atime;
+  ts[0].tv_nsec = (uint64_t)(req->atime * 1000000) % 1000000 * 1000;
+  ts[1].tv_sec  = req->mtime;
+  ts[1].tv_nsec = (uint64_t)(req->mtime * 1000000) % 1000000 * 1000;
+  return utimens(req->path, ts);
+#elif defined(__MVS__)
+  attrib_t atr;
+  memset(&atr, 0, sizeof(atr));
+  atr.att_mtimechg = 1;
+  atr.att_atimechg = 1;
+  atr.att_mtime = req->mtime;
+  atr.att_atime = req->atime;
+  return __lchattr(req->path, &atr, sizeof(atr));
+#else
+  errno = ENOSYS;
+  return -1;
+#endif
 }