--- a/ChangeLog	Tue Oct 09 01:44:07 2018 +0200
+++ b/ChangeLog	Mon Oct 08 16:45:36 2018 -0700
@@ -1,3 +1,17 @@
+2018-10-08  Bernhard Voelker  <mail@bernhard-voelker.de>
+
+	fts: remove FTS_NOATIME
+	This reverts commit da4d6974013c822af1498941e32db774b2031765.
+	We cannot guarantee that O_NOATIME works: e.g. openat fails
+	with EPERM if the effective user ID of the caller does not match
+	the owner of the file and the caller is not privileged.
+	Downstream findutils has never picked up FTS_NOATIME.  Discussed at
+	<https://lists.gnu.org/r/bug-gnulib/2018-09/msg00122.html>.
+	* lib/fts_.h (FTS_NOATIME): Remove bit flag.
+	(FTS_OPTIONMASK): Adjust.
+	* lib/fts.c (diropen, fts_open, fts_build): Likewise.
+	(fd_ring_check): Likewise.
+
 2018-10-08  Bruno Haible  <bruno@clisp.org>
 
 	csharpcomp*, csharpexec*: Remove support for pnet.

--- a/lib/fts.c	Tue Oct 09 01:44:07 2018 +0200
+++ b/lib/fts.c	Mon Oct 08 16:45:36 2018 -0700
@@ -370,8 +370,7 @@
 diropen (FTS const *sp, char const *dir)
 {
   int open_flags = (O_SEARCH | O_CLOEXEC | O_DIRECTORY | O_NOCTTY | O_NONBLOCK
-                    | (ISSET (FTS_PHYSICAL) ? O_NOFOLLOW : 0)
-                    | (ISSET (FTS_NOATIME) ? O_NOATIME : 0));
+                    | (ISSET (FTS_PHYSICAL) ? O_NOFOLLOW : 0));
 
   int fd = (ISSET (FTS_CWDFD)
             ? openat (sp->fts_cwd_fd, dir, open_flags)
@@ -426,8 +425,7 @@
                early, doing it here saves us the trouble of ensuring
                later (where it'd be messier) that "." can in fact
                be opened.  If not, revert to FTS_NOCHDIR mode.  */
-            int fd = open (".",
-                           O_SEARCH | (ISSET (FTS_NOATIME) ? O_NOATIME : 0));
+            int fd = open (".", O_SEARCH);
             if (fd < 0)
               {
                 /* Even if "." is unreadable, don't revert to FTS_NOCHDIR mode
@@ -1304,8 +1302,7 @@
                   (((ISSET(FTS_PHYSICAL)                        \
                      && ! (ISSET(FTS_COMFOLLOW)                 \
                            && cur->fts_level == FTS_ROOTLEVEL)) \
-                    ? O_NOFOLLOW : 0)                           \
-                   | (ISSET (FTS_NOATIME) ? O_NOATIME : 0)),    \
+                    ? O_NOFOLLOW : 0)),                         \
                   Pdir_fd)
 
 /*
@@ -1796,7 +1793,7 @@
       int fd = i_ring_pop (&fd_w);
       if (0 <= fd)
         {
-          int open_flags = O_SEARCH | O_CLOEXEC | O_NOATIME;
+          int open_flags = O_SEARCH | O_CLOEXEC;
           int parent_fd = openat (cwd_fd, "..", open_flags);
           if (parent_fd < 0)
             {

--- a/lib/fts_.h	Tue Oct 09 01:44:07 2018 +0200
+++ b/lib/fts_.h	Mon Oct 08 16:45:36 2018 -0700
@@ -149,7 +149,7 @@
      dirent.d_type data.  */
 # define FTS_DEFER_STAT         0x0400
 
-# define FTS_NOATIME    0x0800          /* use O_NOATIME during traversal */
+/* 0x0800 unused, was non-working FTS_NOATIME */
 
   /* Use this flag to disable stripping of trailing slashes
      from input path names during fts_open initialization.  */