Comment 70 for bug 506798

Hi Kamil,

Using your reproducer (above, thanks!) let's print one more dev/ino pair
(this is on F12):

$ stat --printf "%d %i %n\n" /tmp/mnt/home /tmp/mnt
24 2 /tmp/mnt/home
24 2 /tmp/mnt

That shows a big problem: two distinct directories have the same dev/ino pair,
and fts rightly objects, returning FTS_DC to indicate the directory cycle.
Because when fts encounters the same dev/ino pair twice in a traversal, and when not traversing symlinks, that represents a hard-linked directory cycle, which is usually a big problem. [Note that currently du does not diagnose this problem, but I'll fix that shortly. ]

Even if the above kernel/nfs bug is fixed, I am becoming more and more convinced that this varying-device-number problem is something that must be addressed in the kernel, and not in every single application that must perform dev/ino checks for security. Thanks for reassigning to the kernel.