From nobody Fri Dec 19 15:37:17 2025 Received: from tarta.nabijaczleweli.xyz (tarta.nabijaczleweli.xyz [139.28.40.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 70CD81802F; Thu, 21 Dec 2023 03:09:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nabijaczleweli.xyz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=nabijaczleweli.xyz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=nabijaczleweli.xyz header.i=@nabijaczleweli.xyz header.b="HINY7x7B" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nabijaczleweli.xyz; s=202305; t=1703128160; bh=eC4NraofFatu6EgrcpX+Ng78r0bAeuupM1IBexlD5Ys=; h=Date:From:Cc:Subject:References:In-Reply-To:From; b=HINY7x7BkBUHP9olDZg9BvZ7avlAArx1U47t/vMBnlm8bvXRPUqPOZGu4BP0calNW +qP5WwTZ7m8A6P0Eq0SomxcbT3bjO6+HGgOP3fN8XBVcWzNmwFOfvjG7Sy7qSkxi95 UdNRo5p0d4TaG+0RL5UoMtpy5b0pXrCyKu3RtpYWkylfBHmzNcSw9W8ZERB9ODPDYR omIHfyZXYy55TAZgy23srefzgvzBFACrKKO/7laPUDUgEnO8pbk/d/MzSRLofYJ8GQ 7GjOD2R6/n3A4BCOHdRplwqDvcVp2EjmqpFuxRRdwcDpkQxflvSW1R2lop763rEJCb C6x+K8LGUIZTw== Received: from tarta.nabijaczleweli.xyz (unknown [192.168.1.250]) by tarta.nabijaczleweli.xyz (Postfix) with ESMTPSA id E02471377A; Thu, 21 Dec 2023 04:09:20 +0100 (CET) Date: Thu, 21 Dec 2023 04:09:20 +0100 From: Ahelenia =?utf-8?Q?Ziemia=C5=84ska?= Cc: Jens Axboe , Christian Brauner , Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 11/11] splice: splice_to_socket: always request MSG_DONTWAIT Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="7ll6ly7udayb4srv" Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20231103-116-3b855e-dirty --7ll6ly7udayb4srv Content-Disposition: inline Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The pipe is locked at the top of the function, so sock_sendmsg sleeps for space with the pipe lock held =E2=80=92 given: cat > to_socket.c <<^D #define _GNU_SOURCE #include #include #include #include int main() { int sp[2]; socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0, sp); while(write(sp[1], sp, 1) =3D=3D 1) ; fcntl(sp[1], F_SETFL, 0); for (;;) splice(0, 0, sp[1], 0, 128 * 1024 * 1024, 0); } ^D cc to_socket.c -o to_socket mkfifo fifo sleep 10 > fifo & ./to_socket < fifo & echo zupa > fifo to_socket used to sleep in splice and the shell used to enter an uninterruptible sleep in closing the fifo in dup2(10, 1); now the splice returns -EAGAIN and the whole program completes. Signed-off-by: Ahelenia Ziemia=C5=84ska --- fs/splice.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index 9d29664f23ee..2871c6f9366f 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -869,13 +869,11 @@ ssize_t splice_to_socket(struct pipe_inode_info *pipe= , struct file *out, if (!bc) break; =20 - msg.msg_flags =3D MSG_SPLICE_PAGES; + msg.msg_flags =3D MSG_SPLICE_PAGES | MSG_DONTWAIT; if (flags & SPLICE_F_MORE) msg.msg_flags |=3D MSG_MORE; if (remain && pipe_occupancy(pipe->head, tail) > 0) msg.msg_flags |=3D MSG_MORE; - if (out->f_flags & O_NONBLOCK) - msg.msg_flags |=3D MSG_DONTWAIT; =20 iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, bvec, bc, len - remain); --=20 2.39.2 --7ll6ly7udayb4srv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEfWlHToQCjFzAxEFjvP0LAY0mWPEFAmWDrGAACgkQvP0LAY0m WPGBFg/8DcmEH0+8W+ZzRVYrjfTXuyoYUY7BMRekBTC+JG0lqAf4+BacV0cB1ckq 1Ke39FFciElW6WkZAGan2q9sp8IGIEKRfQEZlgY1iXloYa2PXZpWjfMay/fvAWaf /IFmVYYs5+a5+4Tl424i4adE1+VQzqTA1UF6uxLmhGfQGhrIHUjOeS6OkfpQIhq8 JJvowap4FPJ2Hf2H1v5WmgHVOxGvKkUgbGH/wHSwnAvdaQm7L5YM5WIncBVl/JFx 5xGnnJhwCKNeF7VwauepX34psZsqLaQanGaY8HkkKp+xZt6v15puKl3Two7JAgga WIJhI7ZfIyYrAjLM9aA/yJ0nObZjUM24tdgH5O+/GKFjbT6ImraTSmxP4MtWIJ6O qjQn35qpQlwRCevoXvjGZm60M1howRho9TgoiKNyMdfE0qUkN7Ii2RDSQpgWtlZ9 7lz6aY4f83ZJDKqGp3CkqEIE38q5fbbYstk+LZURkETCD6Ca7sY/JAOP9xyzBEgL Yo2W3qYqxIoVzw6K+MKiZbf90U1neq5vQDLy4/IZw5RAmJ5Lbr9zCabcd5JYvDaY gmpJmQbIu2i5F8Dq/2d/FjIqYKFadLDeMyey4+DspLJBLCF3RdTum/UE4uOw35ut +jn+TgkNM3YSJMa85bvpvNmKqnYW8F/Xqf6KwEPJcenQ+SdiES4= =Gnc5 -----END PGP SIGNATURE----- --7ll6ly7udayb4srv--