Re: extend inotify to support file descriptors in addition to paths

[Giuseppe Scrivano <gscrivano@gnu.org>]

Eric Paris <eparis@parisplace.org> writes:

> On Tue, Sep 8, 2009 at 8:21 PM, Giuseppe Scrivano <gscrivano@gnu.org> wrote:
>
>> at the moment inotify permits to add new files to be watched using their
>> path.  There are situations where the file path is not know but a
>> descriptor is available.  It would be desiderable to have the
>> possibility to use the inotify system even in these (rare) cases.
>
> I don't think specifying the inode in question by fd is fundamentally
> a bad idea.  It is the reason I decided to use fd's when registering
> event's in the upcoming fanotify rather than pathnames.  I do however
> question if we really want to add yet another syscall for inotify.
> We've already seen that inotify is very hard to expand.  The fixed
> message length, lack of information a number of users want, and
> difficultly in extending those things make me reticent to support more
> extentions.

> Personally I'd rather see us/you move to fanotify which is (I hope)
> extensible forever.  If only I could get networking people to review
> it.  Have you looked at fanotify?  I'm going to repost the series in a
> couple minutes, maybe you could tell me if fanotify might work for
> you?

Sure, I'll take a look at it.  I have few questions before look at
details: is it an attempt to replace inotify?  Does fanotify use only
fd?  Have the possibility to watch a file by its path, like inotify
does, is not a bad idea when the file is not already opened.

Thanks,
Giuseppe