On Tue, Apr 26, 2016 at 09:36:23AM -0500, Serge E. Hallyn wrote:

quoted

In the ideal world there is no mountinfo file, but /proc/self/mountinfo/<id>/
directory with individual files, so every subsystem and filesystem has 
absolute freedom to store there all relevant information. The result will 
be also lucky kernel that does not have to always generate entire huge 
mountinfo file for all mountpoins... etc. :-)

Yeah mountinfo does seem like a big stick to swing around every time I want
one little piece of information.  Also mght be good to have per-fstype
directories so we can just look under /proc/self/mountsdir/cgroupfs/ for
only cgroupfs <id>s.

There we might also find open fds for source and mountdir, kinda fitting
in with previous discussions of separating bdev_open() and mountat().

BTW, assuming this would in fact report source and mountpoint location
with fds, these would really (through realpath) be reported relative to
the reader's namespace, as I'm doing and advocating here.

So, what's the consensus here?  Is everyone okay with the posted
patches?

Thanks.

-- 
tejun