Re: [PATCH 3/3] autofs: add ignore mount option

[Ian Kent]

On Tue, 2019-01-29 at 20:58 -0800, Andrew Morton wrote:
> On Wed, 30 Jan 2019 10:07:15 +0800 Ian Kent <raven@xxxxxxxxxx> wrote:
> 
> > On Tue, 2019-01-29 at 17:16 -0800, Andrew Morton wrote:
> > > On Sat, 12 Jan 2019 08:00:40 +0800 Ian Kent <raven@xxxxxxxxxx> wrote:
> > > 
> > > > Add an autofs file system mount option that can be used to provide
> > > > a generic indicator to applications that the mount entry should be
> > > > ignored when displaying mount information.
> > > 
> > > What is the reason for adding this feature?
> > 
> > In other OSes that provide autofs and that provide a mount list
> > to user space based on the kernel mount list a no-op mount option
> > ("ignore" is the one use on the most common OS) is allowed so that
> > autofs file system users can optionally use it.
> > 
> > The idea is that it be used by user space programs to exclude
> > autofs mounts from consideration when reading the mounts list.
> > 
> > Prior to the change to link /etc/mtab to /proc/self/mounts all
> > I needed to do to achieve this was to use mount(2) and not update
> > the mtab but now that no longer works.
> > 
> > I know the symlinking happened a long time ago and I considered
> > doing this then but, at the time I couldn't remember the commonly
> > used option name and thought persuading the various utility
> > maintainers would be too hard.
> > 
> > But now I have a RHEL request to do this for compatibility for a
> > widely used product so I want to go ahead with it and try and
> > enlist the help of some utility package maintainers.
> > 
> > Clearly, without the option nothing can be done so it's at least
> > a start.
> 
> OK.  I guess I can just paste the above into the changelog.

I thought this description would be too long but, by all means,
replace or add it to the changelog.

Or, if you prefer, I could try and come up with something more
succinct, the above explanation probably goes into more detail
than is really needed to get the message across.

> 
> Also, Documentation/filesystems/autofs*.txt are owed an update?

Yes, I think so, I'll have a look at it and get onto it, thanks
for the reminder.

Ian