File coreutils-df_improve_mount_point_selection_with... of Package coreutils.1874

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File coreutils-df_improve_mount_point_selection_with_inaccurate_mount_list.patch of Package coreutils.1874

commit ed1a495b3ccb2665a13229ca866f2115bd768d17
Author: Pádraig Brady <P@draigBrady.com>
Date:   Mon Aug 18 17:59:26 2014 +0100

df: improve mount point selection with inaccurate mount list
    
    v8.23 has a test failure on Fedora rawhide build servers
    in tests/df/skip-duplicate.sh.  This was due to no '/'
    entry being output by df.  That was due to an inaccurate
    /proc/mounts on the build environment as stat(/mnt/point)
    identified all these /proc/mounts entries as having the
    same device id:
    
      /                    rootfs
      /                    /dev/md1
      /dev                 devtmpfs
      /run                 tmpfs
      /boot                /dev/md0
      /proc/filesystems    /dev/md1
    
    Since the device name on the right changes for a given id,
    that causes the entries to be continually replaced, thus
    resulting in no '/' entry.  I'm guessing this is due to
    the mock environment bind mounting unneeded or sensitive
    items to a dummy file on the host / (/dev/md1) though
    have not looked into those details.
    
    So rather than relying on an accurate /proc/mounts,
    the attached patch takes a more conservative replacement
    approach and only swaps a new device entry when the
    mount point matches.  That should handle all practical
    cases while also avoiding this situation.
    
    * src/df.c (filter_mount_list): Only replace entries with
    different device names when the mount point also matches.

diff --git a/src/df.c b/src/df.c
index 3ef5d33..e907b94 100644
--- a/src/df.c
+++ b/src/df.c
@@ -640,13 +640,18 @@ filter_mount_list (bool devices_only)
 
           if (devlist)
             {
-              /* ...let the shorter mountdir win.  */
+                  /* let "real" devices with '/' in the name win.  */
               if ((strchr (me->me_devname, '/')
                    && ! strchr (devlist->me->me_devname, '/'))
+                  /* let a shorter mountdir win.  */
                   || (strlen (devlist->me->me_mountdir)
                       > strlen (me->me_mountdir))
-                  /* or one overmounted on a different device.  */
-                  || ! STREQ (devlist->me->me_devname, me->me_devname))
+                  /* let an entry overmounted on a different device win...  */
+                  || (! STREQ (devlist->me->me_devname, me->me_devname)
+                      /* ... but only when matching an exsiting mount point, to
+                      avoid problematic replacement when given inaccurate mount
+                      lists, seen with some chroot environments for example.  */
+                      && STREQ (me->me_mountdir, devlist->me->me_mountdir)))
                 {
                   /* Discard mount entry for existing device.  */
                   discard_me = devlist->me;

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File coreutils-df_improve_mount_point_selection_with_inaccurate_mount_list.patch of Package coreutils.1874

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