Subject: bug#49298: [PATCH] df: do not print duplicated entires with NFS and bind mounts

From: L A Walsh <[email-masked]>
Date: Thu, 01 Jul 2021 23:23:13 -0700

On 2021/06/30 08:53, Kamil Dudka wrote:
> The proposed patch makes sure that the devlist entry seen the last time
> is used for comparison when eliminating duplicated mount entries.
---
    I'm a bit surprised that the devlists exported for NFS are the same
as for smb.  How is that guaranteed?  But more important, does it work with
other network file systems?  Mostly I'm thinking about mounts of
NTFS from a win server.  I've gotten different results over time, 
specifically,
in regards to whether or not inode numbers are unique.

    Would it be possible for the network file systems to return
different amounts for free+used space depending on the net-interface
being used (I don't know -- I'd hope it wasn't likely, but ....)

    Another way of solving this issue, other than by special casing
SMB+NFS, a switch that prohibits crossing over to another networked
file system, and a different setting that prohibits crossing over to
another device.  I think there is a need for both as well as how initial
args are treated -- as is done with 'find' in all its diversity! ;-)

Patches to reintroduce behaviors that might result in non-deterministic
behaviors are, at least, "worrisome".