tar: --atime-preserve fixes for races etc.

[chaz/tar] / src / compare.c

diff --git a/src/compare.c b/src/compare.c
index 7df3d9853d9dc7ed4b0f15308213e84c8e26ab42..6a873d7b131949bbc05fcb9634e78f90179fef5f 100644 (file)
--- a/src/compare.c
+++ b/src/compare.c
@@ -1,13 +1,13 @@
 /* Diff files from a tar archive.
 
    Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1999, 2000, 2001,
 /* Diff files from a tar archive.
 
    Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1999, 2000, 2001,

-   2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+   2003, 2004, 2005, 2006, 2007, 2009, 2010 Free Software Foundation, Inc.

 
    Written by John Gilmore, on 1987-04-30.
 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
 
    Written by John Gilmore, on 1987-04-30.
 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the

-   Free Software Foundation; either version 2, or (at your option) any later
+   Free Software Foundation; either version 3, or (at your option) any later

    version.
 
    This program is distributed in the hope that it will be useful, but
    version.
 
    This program is distributed in the hope that it will be useful, but


@@ -66,8 +66,7 @@ report_difference (struct tar_stat_info *st, const char *fmt, ...)
       fprintf (stdlis, "\n");
     }
 
       fprintf (stdlis, "\n");
     }
 

-  if (exit_status == TAREXIT_SUCCESS)
-    exit_status = TAREXIT_DIFFERS;
+  set_exit_status (TAREXIT_DIFFERS);

 }
 
 /* Take a buffer returned by read_and_process and do nothing with it.  */
 }
 
 /* Take a buffer returned by read_and_process and do nothing with it.  */


@@ -123,7 +122,7 @@ read_and_process (struct tar_stat_info *st, int (*processor) (size_t, char *))
   size_t data_size;
   off_t size = st->stat.st_size;
 
   size_t data_size;
   off_t size = st->stat.st_size;
 

-  mv_begin (st);
+  mv_begin_read (st);

   while (size)
     {
       data_block = find_next_block ();
   while (size)
     {
       data_block = find_next_block ();


@@ -223,7 +222,9 @@ diff_file (void)
             ? O_NOATIME
             : 0);
 
             ? O_NOATIME
             : 0);
 

-         diff_handle = open (file_name, O_RDONLY | O_BINARY | atime_flag);
+         diff_handle = open (file_name,
+                             (O_RDONLY | O_BINARY | O_CLOEXEC | O_NOCTTY
+                              | O_NONBLOCK | atime_flag));

 
          if (diff_handle < 0)
            {
 
          if (diff_handle < 0)
            {


@@ -242,10 +243,8 @@ diff_file (void)
 
              if (atime_preserve_option == replace_atime_preserve)
                {
 
              if (atime_preserve_option == replace_atime_preserve)
                {

-                 struct timespec ts[2];
-                 ts[0] = get_stat_atime (&stat_data);
-                 ts[1] = get_stat_mtime (&stat_data);
-                 if (set_file_atime (diff_handle, file_name, ts) != 0)
+                 struct timespec atime = get_stat_atime (&stat_data);
+                 if (set_file_atime (diff_handle, file_name, atime, 0) != 0)

                    utime_error (file_name);
                }
 
                    utime_error (file_name);
                }
 


@@ -332,7 +331,7 @@ static int
 dumpdir_cmp (const char *a, const char *b)
 {
   size_t len;
 dumpdir_cmp (const char *a, const char *b)
 {
   size_t len;

-  
+

   while (*a)
     switch (*a)
       {
   while (*a)
     switch (*a)
       {


@@ -346,7 +345,7 @@ dumpdir_cmp (const char *a, const char *b)
        a += len;
        b += len;
        break;
        a += len;
        b += len;
        break;

-       
+

       case 'D':
        if (strcmp(a, b))
          return 1;
       case 'D':
        if (strcmp(a, b))
          return 1;


@@ -354,7 +353,7 @@ dumpdir_cmp (const char *a, const char *b)
        a += len;
        b += len;
        break;
        a += len;
        b += len;
        break;

-       
+

       case 'R':
       case 'T':
       case 'X':
       case 'R':
       case 'T':
       case 'X':


@@ -366,11 +365,11 @@ dumpdir_cmp (const char *a, const char *b)
 static void
 diff_dumpdir (void)
 {
 static void
 diff_dumpdir (void)
 {

-  char *dumpdir_buffer;
+  const char *dumpdir_buffer;

   dev_t dev = 0;
   dev_t dev = 0;

-  struct stat stat;
+  struct stat stat_data;

 
 

-  if (deref_stat (true, current_stat_info.file_name, &stat))
+  if (deref_stat (true, current_stat_info.file_name, &stat_data))

     {
       if (errno == ENOENT)
        stat_warn (current_stat_info.file_name);
     {
       if (errno == ENOENT)
        stat_warn (current_stat_info.file_name);


@@ -378,9 +377,9 @@ diff_dumpdir (void)
        stat_error (current_stat_info.file_name);
     }
   else
        stat_error (current_stat_info.file_name);
     }
   else

-    dev = stat.st_dev;
+    dev = stat_data.st_dev;

 
 

-  dumpdir_buffer = get_directory_contents (current_stat_info.file_name, dev);
+  dumpdir_buffer = directory_contents (scan_directory (&current_stat_info));

 
   if (dumpdir_buffer)
     {
 
   if (dumpdir_buffer)
     {


@@ -397,6 +396,10 @@ diff_multivol (void)
   struct stat stat_data;
   int fd, status;
   off_t offset;
   struct stat stat_data;
   int fd, status;
   off_t offset;

+  int atime_flag =
+    (atime_preserve_option == system_atime_preserve
+     ? O_NOATIME
+     : 0);

 
   if (current_stat_info.had_trailing_slash)
     {
 
   if (current_stat_info.had_trailing_slash)
     {


@@ -422,7 +425,10 @@ diff_multivol (void)
       return;
     }
 
       return;
     }
 

-  fd = open (current_stat_info.file_name, O_RDONLY | O_BINARY);
+
+  fd = open (current_stat_info.file_name,
+            (O_RDONLY | O_BINARY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK
+             | atime_flag));

 
   if (fd < 0)
     {
 
   if (fd < 0)
     {


@@ -452,7 +458,6 @@ diff_archive (void)
 {
 
   set_next_block_after (current_header);
 {
 
   set_next_block_after (current_header);

-  decode_header (current_header, &current_stat_info, &current_format, 1);

 
   /* Print the block from current_header and current_stat_info.  */
 
 
   /* Print the block from current_header and current_stat_info.  */
 


@@ -460,7 +465,7 @@ diff_archive (void)
     {
       if (now_verifying)
        fprintf (stdlis, _("Verify "));
     {
       if (now_verifying)
        fprintf (stdlis, _("Verify "));

-      print_header (&current_stat_info, -1);
+      print_header (&current_stat_info, current_header, -1);

     }
 
   switch (current_header->header.typeflag)
     }
 
   switch (current_header->header.typeflag)


@@ -578,7 +583,9 @@ verify_volume (void)
   flush_read ();
   while (1)
     {
   flush_read ();
   while (1)
     {

-      enum read_header status = read_header (false);
+      enum read_header status = read_header (&current_header,
+                                             &current_stat_info,
+                                             read_header_auto);

 
       if (status == HEADER_FAILURE)
        {
 
       if (status == HEADER_FAILURE)
        {


@@ -588,7 +595,8 @@ verify_volume (void)
            {
              counter++;
              set_next_block_after (current_header);
            {
              counter++;
              set_next_block_after (current_header);

-             status = read_header (false);
+             status = read_header (&current_header, &current_stat_info,
+                                   read_header_auto);

            }
          while (status == HEADER_FAILURE);
 
            }
          while (status == HEADER_FAILURE);
 


@@ -597,8 +605,24 @@ verify_volume (void)
                            "VERIFY FAILURE: %d invalid headers detected",
                            counter), counter));
        }
                            "VERIFY FAILURE: %d invalid headers detected",
                            counter), counter));
        }

-      if (status == HEADER_ZERO_BLOCK || status == HEADER_END_OF_FILE)
+      if (status == HEADER_END_OF_FILE)

        break;
        break;

+      if (status == HEADER_ZERO_BLOCK)
+       {
+         set_next_block_after (current_header);
+          if (!ignore_zeros_option)
+            {
+             char buf[UINTMAX_STRSIZE_BOUND];
+
+             status = read_header (&current_header, &current_stat_info,
+                                   read_header_auto);
+             if (status == HEADER_ZERO_BLOCK)
+               break;
+             WARNOPT (WARN_ALONE_ZERO_BLOCK,
+                      (0, 0, _("A lone zero block at %s"),
+                       STRINGIFY_BIGINT (current_block_ordinal (), buf)));
+            }
+       }

 
       diff_archive ();
       tar_stat_destroy (&current_stat_info);
 
       diff_archive ();
       tar_stat_destroy (&current_stat_info);