From 0ab6e8b324d8dcb9159bdd100538d4e9852f96a6 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Thu, 11 May 2017 10:23:36 -0400
Subject: [PATCH] basic/fileio: extend atomic file writing with timestamp
 setting

There should be no functional change.
---
 src/basic/fileio-label.c |  4 ++--
 src/basic/fileio-label.h |  5 ++++-
 src/basic/fileio.c       | 16 ++++++++++++----
 src/basic/fileio.h       | 10 ++++++++--
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/src/basic/fileio-label.c b/src/basic/fileio-label.c
index 728267006..4cb207742 100644
--- a/src/basic/fileio-label.c
+++ b/src/basic/fileio-label.c
@@ -24,14 +24,14 @@
 //#include "fileio.h"
 #include "selinux-util.h"
 
-int write_string_file_atomic_label(const char *fn, const char *line) {
+int write_string_file_atomic_label_ts(const char *fn, const char *line, struct timespec *ts) {
         int r;
 
         r = mac_selinux_create_file_prepare(fn, S_IFREG);
         if (r < 0)
                 return r;
 
-        r = write_string_file(fn, line, WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC);
+        r = write_string_file_ts(fn, line, WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC, ts);
 
         mac_selinux_create_file_clear();
 
diff --git a/src/basic/fileio-label.h b/src/basic/fileio-label.h
index 4deeef252..d811ca9b8 100644
--- a/src/basic/fileio-label.h
+++ b/src/basic/fileio-label.h
@@ -24,7 +24,10 @@
 
 #include "fileio.h"
 
-int write_string_file_atomic_label(const char *fn, const char *line);
+int write_string_file_atomic_label_ts(const char *fn, const char *line, struct timespec *ts);
+static inline int write_string_file_atomic_label(const char *fn, const char *line) {
+        return write_string_file_atomic_label_ts(fn, line, NULL);
+}
 #if 0 /// UNNEEDED by elogind
 int write_env_file_label(const char *fname, char **l);
 int fopen_temporary_label(const char *target,
diff --git a/src/basic/fileio.c b/src/basic/fileio.c
index 13f610771..7bafe9038 100644
--- a/src/basic/fileio.c
+++ b/src/basic/fileio.c
@@ -50,7 +50,7 @@
 
 #define READ_FULL_BYTES_MAX (4U*1024U*1024U)
 
-int write_string_stream(FILE *f, const char *line, bool enforce_newline) {
+int write_string_stream_ts(FILE *f, const char *line, bool enforce_newline, struct timespec *ts) {
 
         assert(f);
         assert(line);
@@ -59,6 +59,13 @@ int write_string_stream(FILE *f, const char *line, bool enforce_newline) {
         if (enforce_newline && !endswith(line, "\n"))
                 fputc('\n', f);
 
+        if (ts) {
+                struct timespec twice[2] = {*ts, *ts};
+
+                if (futimens(fileno(f), twice) < 0)
+                        return -errno;
+        }
+
         return fflush_and_check(f);
 }
 
@@ -88,7 +95,7 @@ static int write_string_file_atomic(const char *fn, const char *line, bool enfor
         return r;
 }
 
-int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags) {
+int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags flags, struct timespec *ts) {
         _cleanup_fclose_ FILE *f = NULL;
         int q, r;
 
@@ -103,7 +110,8 @@ int write_string_file(const char *fn, const char *line, WriteStringFileFlags fla
                         goto fail;
 
                 return r;
-        }
+        } else
+                assert(ts == NULL);
 
         if (flags & WRITE_STRING_FILE_CREATE) {
                 f = fopen(fn, "we");
@@ -130,7 +138,7 @@ int write_string_file(const char *fn, const char *line, WriteStringFileFlags fla
                 }
         }
 
-        r = write_string_stream(f, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE));
+        r = write_string_stream_ts(f, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE), ts);
         if (r < 0)
                 goto fail;
 
diff --git a/src/basic/fileio.h b/src/basic/fileio.h
index a614d8998..fa223fdf5 100644
--- a/src/basic/fileio.h
+++ b/src/basic/fileio.h
@@ -35,8 +35,14 @@ typedef enum {
         WRITE_STRING_FILE_VERIFY_ON_FAILURE = 8,
 } WriteStringFileFlags;
 
-int write_string_stream(FILE *f, const char *line, bool enforce_newline);
-int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags);
+int write_string_stream_ts(FILE *f, const char *line, bool enforce_newline, struct timespec *ts);
+static inline int write_string_stream(FILE *f, const char *line, bool enforce_newline) {
+        return write_string_stream_ts(f, line, enforce_newline, NULL);
+}
+int write_string_file_ts(const char *fn, const char *line, WriteStringFileFlags flags, struct timespec *ts);
+static inline int write_string_file(const char *fn, const char *line, WriteStringFileFlags flags) {
+        return write_string_file_ts(fn, line, flags, NULL);
+}
 
 int read_one_line_file(const char *fn, char **line);
 int read_full_file(const char *fn, char **contents, size_t *size);
-- 
2.30.2