Dick Streefland <[email protected]> writes: > After a recent upgrade of a Ubuntu xenial machine, a particular > autofs multi-map mount setup stopped working. A simplified example is: > > :::::::::::::: > auto.master > :::::::::::::: > /net /etc/auto.net > :::::::::::::: > auto.net > :::::::::::::: > localhost / :/ /loc :/loc > > Accessing /net/localhost/loc should trigger two nested bind mounts on > /net/localhost and /net/localhost/loc, but with the new kernel, it fails > with ELOOP: > > $ ls /net/localhost/loc > ls: cannot open directory '/net/localhost/loc': Too many levels of symbolic > links > > The problem is related to the upgrade of the Ubuntu xenial kernel from > 4.4.0-38.57 to 4.4.0-78.99. I bisected the regression to commit > 731ac92843877f3633325203abc942193c1e9001, which is a Ubuntu backport > of this upstream kernel commit: > > commit 1064f874abc0d05eeed8993815f584d847b72486 > Author: Eric W. Biederman <[email protected]> > Date: Fri Jan 20 18:28:35 2017 +1300 > > mnt: Tuck mounts under others instead of creating shadow/side mounts.
Interesting... Can you test this on a stock 4.11 kernel? I definitely need a little bit more information to solve this. That commit did not add any new error condidtions so I need to understand what state you are getting yourself into that is affected by this commit. Is there a chance you can post /proc/self/mountinfo from when this is happening? Eric
