bug#9140: fsusage: revert unintended change on AIX, Cygwin, Interix

[Bruno Haible]

> 2) To undo the patch that introduces check_f_blocks_size, because
>      - on MacOS X 10.7 it is not needed any more after 1),
>      - on AIX and Cywin it causes non-POSIX API to be used for no reason,
>      - it kills portability to Interix 3.5.

Slight correction: It is still needed after 1), at least on MacOS X 10.5.
But only on MacOS X. So here's the proposed patch 2. Verified on AIX and
Cygwin; I don't have access to an Interix machine.


2011-07-23  Bruno Haible  <address@hidden>

        fsusage: Restore previous behaviour on AIX, Cygwin, Interix.
        * m4/fsusage.m4 (gl_FILE_SYSTEM_USAGE): Enforce a 64-bit struct statvfs
        f_blocks field only on MacOS X.

*** m4/fsusage.m4.orig  Sat Jul 23 16:44:07 2011
--- m4/fsusage.m4       Sat Jul 23 16:42:32 2011
***************
*** 62,75 ****
  "Do not use Tru64's statvfs implementation"
  #endif
  
- #include <limits.h>
  #include <sys/statvfs.h>
  
- /* Reject implementations, such as MacOS X 10.7, where f_blocks is a
-    32-bit quantity; that commonly limits file systems to 4 TiB, a
-    ridiculously small limit these days.  */
  struct statvfs fsd;
  int check_f_blocks_size[sizeof fsd.f_blocks * CHAR_BIT <= 32 ? -1 : 1];
  ]],
                                      [[statvfs (0, &fsd);]])],
                                   [fu_cv_sys_stat_statvfs=yes],
--- 62,80 ----
  "Do not use Tru64's statvfs implementation"
  #endif
  
  #include <sys/statvfs.h>
  
  struct statvfs fsd;
+ 
+ #if defined __APPLE__ && defined __MACH__
+ #include <limits.h>
+ /* On MacOS X >= 10.5, f_blocks in 'struct statvfs' is a 32-bit quantity;
+   that commonly limits file systems to 4 TiB.  Whereas f_blocks in
+   'struct statfs' is a 64-bit type, thanks to the large-file support
+   that was enabled above.  In this case, don't use statvfs(); use statfs()
+   instead.  */
  int check_f_blocks_size[sizeof fsd.f_blocks * CHAR_BIT <= 32 ? -1 : 1];
+ #endif
  ]],
                                      [[statvfs (0, &fsd);]])],
                                   [fu_cv_sys_stat_statvfs=yes],
-- 
In memoriam Adam Czerniaków <http://en.wikipedia.org/wiki/Adam_Czerniaków>