On 2020-01-02, David Laight [off-list ref] wrote:

From: Aleksa Sarai

quoted

Sent: 30 December 2019 08:32

...

quoted

I'm not sure I agree -- as I mentioned in my other mail, re-opening
through /proc/self/fd/$n works *very* well and has for a long time (in
fact, both LXC and runc depend on this working).

I thought it was marginally broken because it is followed as a symlink?
On, for example, NetBSD /proc/<n>/fd/<n> is a real reference to the
filesystem inode and can be used to link the file back into the filesystem
if all the directory entries have been removed.

That is also the case on Linux. It (strictly speaking) isn't a symlink
in the normal sense of the word, it's a magic-link (nd_jump_link
switches the nd->path to the actual 'struct file' in the case of
/proc/self/fd/$n).

-- 
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>