Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 26 Jun 2023 14:57:55 +0200
From:   Ahelenia =?utf-8?Q?Ziemia=C5=84ska?= 
        <nabijaczleweli@nabijaczleweli.xyz>
To:     Amir Goldstein <amir73il@gmail.com>
Cc:     Alexander Viro <viro@zeniv.linux.org.uk>,
        Christian Brauner <brauner@kernel.org>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jan Kara <jack@suse.cz>
Subject: Re: splice(-> FIFO) never wakes up inotify IN_MODIFY?
Message-ID: <vlzqpije6ltf2jga7btkccraxxnucxrcsqbskdnk6s2sarkitb@5huvtml62a5c>
References: <jbyihkyk5dtaohdwjyivambb2gffyjs3dodpofafnkkunxq7bu@jngkdxx65pux>
 <CAOQ4uxhut2NHc+MY-XOJay5B-OKXU2X5Fe0-6-RCMKt584ft5A@mail.gmail.com>
 <ndm45oojyc5swspfxejfq4nd635xnx5m35otsireckxp6heduh@2opifgi3b3cw>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
        protocol="application/pgp-signature"; boundary="ekt4xsobei4itlj7"
Content-Disposition: inline
In-Reply-To: <ndm45oojyc5swspfxejfq4nd635xnx5m35otsireckxp6heduh@2opifgi3b3cw>
User-Agent: NeoMutt/20230517
Precedence: bulk


--ekt4xsobei4itlj7
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Mon, Jun 26, 2023 at 02:19:42PM +0200, Ahelenia Ziemia=C5=84ska wrote:
> > splice(2) differentiates three different cases:
> >         if (ipipe && opipe) {
> > ...
> >         if (ipipe) {
> > ...
> >         if (opipe) {
> > ...
> >=20
> > IN_ACCESS will only be generated for non-pipe input
> > IN_MODIFY will only be generated for non-pipe output
> >
> > Similarly FAN_ACCESS_PERM fanotify permission events
> > will only be generated for non-pipe input.
Sorry, I must've misunderstood this as "splicing to a pipe generates
*ACCESS". Testing reveals this is not the case. So is it really true
that the only way to poll a pipe is a sleep()/read(O_NONBLOCK) loop?

--ekt4xsobei4itlj7
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=ZCkQ
-----END PGP SIGNATURE-----

--ekt4xsobei4itlj7--