--- tar-1.23/src/buffer.c.bak	2010-03-09 14:52:41.000000000 +0200
+++ tar-1.23/src/buffer.c	2010-03-14 07:42:11.176656974 +0200
@@ -890,6 +890,8 @@ seek_archive (off_t size)
 void
 close_archive (void)
 {
+  int ret;
+
   if (time_to_start_writing || access_mode == ACCESS_WRITE)
     {
       flush_archive ();
@@ -901,6 +903,11 @@ close_archive (void)
   if (verify_option)
     verify_volume ();
 
+  ret = sys_fsync_archive();
+  if (ret != 0) {
+    archive_write_error (errno);
+  }
+
   if (rmtclose (archive) != 0)
     close_error (*archive_name_cursor);
 
--- tar-1.23/src/system.c.bak	2010-03-14 07:40:46.104657738 +0200
+++ tar-1.23/src/system.c	2010-03-14 07:42:11.233657442 +0200
@@ -96,6 +96,12 @@ sys_write_archive_buffer (void)
   return full_write (archive, record_start->buffer, record_size);
 }
 
+int
+sys_fsync_archive (void)
+{
+  return 0;
+}
+
 /* Set ARCHIVE for writing, then compressing an archive.  */
 void
 sys_child_open_for_compress (void)
@@ -269,6 +275,20 @@ sys_write_archive_buffer (void)
   return rmtwrite (archive, record_start->buffer, record_size);
 }
 
+int
+sys_fsync_archive (void)
+{
+  int ret;
+
+  if (do_fsync && !use_compress_program_option /* can't fsync pipe */ ) {
+    ret = fsync (archive);
+    if ((ret == -1) && (errno == EINVAL)) return 0;
+    return ret;
+  } else {
+    return 0;
+  }
+}
+
 #define	PREAD 0			/* read file descriptor from pipe() */
 #define	PWRITE 1		/* write file descriptor from pipe() */
 
--- tar-1.23/src/tar.c.bak	2010-03-14 07:40:48.344655641 +0200
+++ tar-1.23/src/tar.c	2010-03-14 07:44:39.726657796 +0200
@@ -746,6 +746,8 @@ static struct argp_option options[] = {
    N_("wildcards do not match `/'"), GRID+1 },
   {"wildcards-match-slash", WILDCARDS_MATCH_SLASH_OPTION, 0, 0,
    N_("wildcards match `/' (default for exclusion)"), GRID+1 },
+  {"fsync", 'q', 0, 0,
+   N_("when creating archive, fsync it prior to closing"), GRID+1},
 #undef GRID
 
 #define GRID 130
@@ -1593,6 +1595,11 @@ parse_opt (int key, char *arg, struct ar
       absolute_names_option = true;
       break;
       
+    case 'q':
+      do_fsync = true;
+      setenv("TAR_WANTS_FSYNC", "", 1);
+      break;
+      
     case 'r':
       set_subcommand_option (APPEND_SUBCOMMAND);
       break;
@@ -2642,6 +2649,9 @@ main (int argc, char **argv)
   /* System V fork+wait does not work if SIGCHLD is ignored.  */
   signal (SIGCHLD, SIG_DFL);
 
+  if (getenv("TAR_WANTS_FSYNC"))
+    do_fsync = true;
+
   /* Try to disable the ability to unlink a directory.  */
   priv_set_remove_linkdir ();
   
--- tar-1.23/src/common.h.bak	2010-03-14 07:40:46.373654580 +0200
+++ tar-1.23/src/common.h	2010-03-14 07:42:11.216660001 +0200
@@ -106,6 +106,9 @@ GLOBAL bool absolute_names_option;
 /* Display file times in UTC */
 GLOBAL bool utc_option;
 
+/* fsync() written archives prior to close() */
+GLOBAL bool do_fsync;
+
 /* This variable tells how to interpret newer_mtime_option, below.  If zero,
    files get archived if their mtime is not less than newer_mtime_option.
    If nonzero, files get archived if *either* their ctime or mtime is not less
@@ -786,6 +789,7 @@ int sys_truncate (int fd);
 pid_t sys_child_open_for_compress (void);
 pid_t sys_child_open_for_uncompress (void);
 size_t sys_write_archive_buffer (void);
+int sys_fsync_archive (void);
 bool sys_get_archive_stat (void);
 int sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st);
 void sys_wait_command (void);