Optionally preserve atimes.
    
Based on https://bugzilla.samba.org/show_bug.cgi?id=7249#c1 by Nicolas George.

Index: rsync-3.1.0/options.c
===================================================================
--- rsync-3.1.0.orig/options.c
+++ rsync-3.1.0/options.c
@@ -125,6 +125,7 @@ int delay_updates = 0;
 long block_size = 0; /* "long" because popt can't set an int32. */
 char *skip_compress = NULL;
 item_list dparam_list = EMPTY_ITEM_LIST;
+int noatime = 0;
 
 /** Network address family. **/
 int default_af_hint
@@ -802,6 +803,7 @@ void usage(enum logcode F)
   rprintf(F,"     --iconv=CONVERT_SPEC    request charset conversion of filenames\n");
 #endif
   rprintf(F,"     --checksum-seed=NUM     set block/file checksum seed (advanced)\n");
+  rprintf(F,"     --noatime               do not alter atime when opening source files\n");
   rprintf(F," -4, --ipv4                  prefer IPv4\n");
   rprintf(F," -6, --ipv6                  prefer IPv6\n");
   rprintf(F,"     --version               print version number\n");
@@ -1019,6 +1021,7 @@ static struct poptOption long_options[]
   {"iconv",            0,  POPT_ARG_STRING, &iconv_opt, 0, 0, 0 },
   {"no-iconv",         0,  POPT_ARG_NONE,   0, OPT_NO_ICONV, 0, 0 },
 #endif
+  {"noatime",          0,  POPT_ARG_VAL,    &noatime, 1, 0, 0 },
   {"ipv4",            '4', POPT_ARG_VAL,    &default_af_hint, AF_INET, 0, 0 },
   {"ipv6",            '6', POPT_ARG_VAL,    &default_af_hint, AF_INET6, 0, 0 },
   {"8-bit-output",    '8', POPT_ARG_VAL,    &allow_8bit_chars, 1, 0, 0 },
@@ -2739,6 +2742,12 @@ void server_options(char **args, int *ar
 	if (preallocate_files && am_sender)
 		args[ac++] = "--preallocate";
 
+	/*
+	 * Do we want remote atime preservation when we preserve local ones?
+	if (noatime)
+		args[ac++] = "--noatime";
+	*/
+
 	if (ac > MAX_SERVER_ARGS) { /* Not possible... */
 		rprintf(FERROR, "argc overflow in server_options().\n");
 		exit_cleanup(RERR_MALLOC);
Index: rsync-3.1.0/rsync.yo
===================================================================
--- rsync-3.1.0.orig/rsync.yo
+++ rsync-3.1.0/rsync.yo
@@ -454,6 +454,7 @@ to the detailed description below for a
      --protocol=NUM          force an older protocol version to be used
      --iconv=CONVERT_SPEC    request charset conversion of filenames
      --checksum-seed=NUM     set block/file checksum seed (advanced)
+     --noatime               do not alter atime when opening source files
  -4, --ipv4                  prefer IPv4
  -6, --ipv6                  prefer IPv6
      --version               print version number
@@ -2543,6 +2544,13 @@ daemon uses the charset specified in its
 regardless of the remote charset you actually pass.  Thus, you may feel free to
 specify just the local charset for a daemon transfer (e.g. bf(--iconv=utf8)).
 
+dit(bf(--noatime)) Use the O_NOATIME open flag on systems that support it.
+The effect of this flag is to avoid altering the access time (atime) of the
+opened files.
+If the system does not support the O_NOATIME flag, this option does nothing.
+Currently, systems known to support O_NOATIME are Linux >= 2.6.8 with glibc
+>= 2.3.4.
+
 dit(bf(-4, --ipv4) or bf(-6, --ipv6)) Tells rsync to prefer IPv4/IPv6
 when creating sockets.  This only affects sockets that rsync has direct
 control over, such as the outgoing socket when directly contacting an
Index: rsync-3.1.0/syscall.c
===================================================================
--- rsync-3.1.0.orig/syscall.c
+++ rsync-3.1.0/syscall.c
@@ -40,6 +40,7 @@ extern int read_only;
 extern int list_only;
 extern int preserve_perms;
 extern int preserve_executability;
+extern int noatime;
 
 #define RETURN_ERROR_IF(x,e) \
 	do { \
@@ -189,6 +190,10 @@ int do_open(const char *pathname, int fl
 		RETURN_ERROR_IF(dry_run, 0);
 		RETURN_ERROR_IF_RO_OR_LO;
 	}
+#ifdef O_NOATIME
+	if (noatime)
+		flags |= O_NOATIME;
+#endif
 
 	return open(pathname, flags | O_BINARY, mode);
 }