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

[Henry Wilson <henry.wilson@acentic.com>]

On 30/05/18 17:04, Jan Kara wrote:
> 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 shall have a go at writing a test, yes.

>>
>> 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).

Ah, I did not know linux-api needed to be cc'ed in.

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

For reference here is an archive link to the thread on the linux-man archive
https://marc.info/?l=linux-man&m=152769572917930&w=2

> 
>> 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)?
IN_MASK_CREATE seems the most logical to me too.
I'm happy to resubmit the patch if necessary.

> 
>> Maybe include linux-api in the discussion?
> 
> Probably we should, added.
> 
> 								Honza
>