[Bug-gnulib] fsusage.m4 statvfs-testing for glibc (merge from coreutils)

[Paul Eggert]

I installed this merge from coreutils:

2003-08-16  Jim Meyering  <address@hidden>

        * fsusage.m4 [__GLIBC__]: GNU libc's statvfs stats each mount point in
        /proc/mounts until it finds one with matching device number.  This is
        unnecessary when the FILE argument *is* a mount point.  No stat call
        is necessary in that case.  So, disable the statvfs-testing code on
        systems with GNU libc.  Reported by Andrei Gaponenko via Tim Waugh
        as RedHat bug# 84846.

Index: m4/fsusage.m4
===================================================================
RCS file: /cvsroot/gnulib/gnulib/m4/fsusage.m4,v
retrieving revision 1.16
diff -p -u -r1.16 fsusage.m4
--- m4/fsusage.m4       29 May 2003 07:21:59 -0000      1.16
+++ m4/fsusage.m4       16 Aug 2003 08:25:54 -0000
@@ -1,4 +1,4 @@
-#serial 10
+#serial 11
 
 # From fileutils/configure.in
 
@@ -35,6 +35,11 @@ if test $ac_fsusage_space = no; then
   # SVR4
   AC_CACHE_CHECK([for statvfs function (SVR4)], fu_cv_sys_stat_statvfs,
                 [AC_TRY_LINK([#include <sys/types.h>
+#ifdef __GLIBC__
+Do not use statvfs on systems with GNU libc, because that function stats
+all preceding entries in /proc/mounts, and that makes df hang if even
+one of the corresponding file systems is hard-mounted, but not available.
+#endif
 #include <sys/statvfs.h>],
                              [struct statvfs fsd; statvfs (0, &fsd);],
                              fu_cv_sys_stat_statvfs=yes,