Re: No error when inotify_add_watch(/an/NFS/file)

["J. Bruce Fields" <bfields@fieldses.org>]

On Fri, Nov 23, 2007 at 11:20:55PM +0000, Phil Endecott wrote:
> Dear Experts,
>
> NFS doesn't work with inotify (and it looks like it can't, certainly not 
> before NFS v4.1).  However, if I give an NFS filename to 
> inotify_add_watch(), I don't get an error.
>
> If it indicated an error in this case then I could easily fall back to some 
> sort of polling.  Without an error, I need some other way to detect NFS 
> (and any other non-inotify-compatible filesystems).
>
> Any thoughts?

The one reason I can think of that you might want that behavior is if
you know you only access a given piece of the filesystem from one client
at a time, and you still want inotify to work in that situation.  (I'm
assuming inotify still notifies you of changes that are made on the same
client.)

But maybe you could handle that case by allowing inotify_add_watch() in
the case where the nfs filesystem was mounted with the "nolock" option,
and failing it otherwise, and telling people to turn on nolock if
they're sure they know what they're doing.

--b.