Re: [PATCH v3 4.17] inotify: Add flag IN_EXCL_ADD for inotify_add_watch()

From: Jan Kara <jack@suse.cz>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Henry Wilson <henry.wilson@acentic.com>, Jan Kara <jack@suse.cz>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	linux-api@vger.kernel.org
Subject: Re: [PATCH v3 4.17] inotify: Add flag IN_EXCL_ADD for inotify_add_watch()
Date: Wed, 30 May 2018 18:04:27 +0200	[thread overview]
Message-ID: <20180530160427.qs2dykrx3ohqm3bf@quack2.suse.cz> (raw)
In-Reply-To: <CAOQ4uxiAEgh=41sSzvdm+wGJPR5-+vBiLoxnfKDRDbUcpihr5Q@mail.gmail.com>

On Wed 30-05-18 18:40:27, Amir Goldstein wrote:
> On Wed, May 30, 2018 at 4:35 PM, Henry Wilson <henry.wilson@acentic.com> wrote:
> > On 30/05/18 14:01, Jan Kara wrote:
> >>
> >> Thanks. The patch looks good. I've added it to my tree. BTW, do you plan
> >> on
> >> working on a similar addition to fanotify?
> >>
> >>                                                                 Honza
> >>
> >
> > Ah that's grand, I'm glad to have helped to improve things.
> > I'm not familiar with fanotify, however a quick look at fanotify_user.c
> > suggests that a similar approach may be taken by modifying:
> >
> > if(!fsn_mark) {
> >         ...
> > }
> > else if (create) {
> >         return -EEXIST;
> > }
> >
> > in both fanotify_add_vfsmount_mark() and fanotify_add_inode_mark()
> >
> 
> I think that was a yes/no question and I interpret your answer as no??
> 
> Anyway, another yes/no question:
> Can you write a simple LTP test to verify the new API?
> 
> I reccon Jan was also expecting an actual patch posted to man pages
> maintainer (and linux-api, which was not cc'ed on the latest patch).

Yes, and I think Henry is about to post it, just didn't get to it yet.

> About the fanotify change, since fanotify API does have 'flags' separate
> from 'mask', I am not sure if FAN_MARK_EXCL_ADD would be the
> best flag name?? Perhaps FAN_MARK_CREATE? FAN_MARK_NEW?
> not sure.

Yes, for fanotify we could choose a different name.

> But also, I did not get a chance to comment about the chosen inotify
> flag name that the lexical proximity to IN_EXCL_UNLINK is a bit odd
> considering that _EXCL_ mean two completely different things.
> 
> Should we maybe re-consider the chosen flag name?

I'm open to that, I have the patch just sitting in an internal branch for
now. Do you have a better suggestion? Maybe since we already have
IN_MASK_ADD, we could call it IN_MASK_CREATE? And then FAN_MARK_CREATE for
fanotify_mark(2)?

> Maybe include linux-api in the discussion?

Probably we should, added.

								Honza

-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR