From e6f48ae9bff7b5dc8027d043aa1bffa53d507a42 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ale=C5=A1=20Mat=C4=9Bj?= <amatej@redhat.com>
Date: Thu, 5 May 2022 12:44:27 +0200
Subject: [PATCH] Use nanosec precision for timestamp of checksum cache
 (RhBug:2077864)

= changelog =
msg: Use nanosec precision for timestamp of checksum cache
type: bugfix
resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2077864
---
 librepo/checksum.c    | 7 +++++--
 tests/test_checksum.c | 6 +++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/librepo/checksum.c b/librepo/checksum.c
index 6bba53c..d82cb5c 100644
--- a/librepo/checksum.c
+++ b/librepo/checksum.c
@@ -18,6 +18,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#define _POSIX_C_SOURCE 200809L
 #include <glib.h>
 #include <glib/gprintf.h>
 #include <assert.h>
@@ -217,16 +218,18 @@ lr_checksum_fd_compare(LrChecksumType type,
         return FALSE;
     }
 
-    time_t timestamp = -1;
+    long long timestamp = -1;
 
     if (caching) {
         struct stat st;
         if (fstat(fd, &st) == 0) {
             timestamp = st.st_mtime;
+            timestamp *= 1000000000; //convert sec timestamp to nanosec timestamp
+            timestamp += st.st_mtim.tv_nsec;
         }
     }
 
-    _cleanup_free_ gchar *timestamp_str = g_strdup_printf("%lli", (long long)timestamp);
+    _cleanup_free_ gchar *timestamp_str = g_strdup_printf("%lli", timestamp);
     const char *type_str = lr_checksum_type_to_str(type);
     _cleanup_free_ gchar *timestamp_key = g_strconcat(XATTR_CHKSUM_PREFIX, "mtime", NULL);
     _cleanup_free_ gchar *checksum_key = g_strconcat(XATTR_CHKSUM_PREFIX, type_str, NULL);
diff --git a/tests/test_checksum.c b/tests/test_checksum.c
index cd28cd1..548f588 100644
--- a/tests/test_checksum.c
+++ b/tests/test_checksum.c
@@ -1,3 +1,4 @@
+#define _POSIX_C_SOURCE 200809L
 #define _GNU_SOURCE
 #include <errno.h>
 #include <stdlib.h>
@@ -150,7 +151,10 @@ START_TEST(test_cached_checksum_matches)
     // stored timestamp matches the file mtime
     ret = stat(filename, &st);
     ck_assert_int_eq(ret, 0);
-    mtime_str = g_strdup_printf("%lli", (long long) st.st_mtime);
+    long long timestamp = st.st_mtime;
+    timestamp *= 1000000000; //convert sec timestamp to nanosec timestamp
+    timestamp += st.st_mtim.tv_nsec;
+    mtime_str = g_strdup_printf("%lli", timestamp);
     attr_ret = GETXATTR(filename, timestamp_key, &buf, sizeof(buf)-1);
     ck_assert(attr_ret != -1);
     buf[attr_ret] = 0;
-- 
2.36.1