From patchwork Thu Dec 21 03:09:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ahelenia_Ziemia=C5=84ska?= X-Patchwork-Id: 757435 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 52D4118035; Thu, 21 Dec 2023 03:09:12 +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="WnvVBEoU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nabijaczleweli.xyz; s=202305; t=1703128150; bh=Jm7XzHnqDG9iwaDHGTe5ldutgziwWY+ScUPkOH8HCS0=; h=Date:From:Cc:Subject:References:In-Reply-To:From; b=WnvVBEoUJFMt79/ZV/pfyW1Dj4U9GOMXgiBmZdAw8p9y5MsOYMkGKNgVs3tq+RU6q kGnfCNltQC7vfNESPY2wuggMkbwywOgPLzEnOk1DdWumqI+LIGHIr0QpVwln7sXyjB lKQorhc2w9446jX2cHwSLOOu71JnHxShnnPyuhXTaZ8pvYdiQeRgdn1bj8E2c9kY5F Fn6w3hCwRNqO0qeq2ZHQ45u+XzoiSBMDe/lVVvxBHuXNTfwGnlJfDohjOydzALdzpY 22tTHAkwi0hnuRAlEnPYbDsIC+ZZaBuZBmd7AmHAROo5cxShp3A7BwkHLstbwXqFc9 iIY5IRYM8cZiA== Received: from tarta.nabijaczleweli.xyz (unknown [192.168.1.250]) by tarta.nabijaczleweli.xyz (Postfix) with ESMTPSA id CB40D13778; Thu, 21 Dec 2023 04:09:10 +0100 (CET) Date: Thu, 21 Dec 2023 04:09:10 +0100 From: Ahelenia =?utf-8?q?Ziemia=C5=84ska?= Cc: Jens Axboe , Christian Brauner , Alexander Viro , linux-fsdevel@vger.kernel.org, Greg Kroah-Hartman , Jiri Slaby , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: [PATCH v2 08/11] tty: splice_read: disable Message-ID: <4dec932dcd027aa5836d70a6d6bedd55914c84c2.1703126594.git.nabijaczleweli@nabijaczleweli.xyz> References: Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20231103-116-3b855e-dirty We request non-blocking I/O in the generic copy_splice_read, but "the tty layer doesn't actually honor the IOCB_NOWAIT flag for various historical reasons.". This means that a tty->pipe splice will happily sleep with the pipe locked forever, and any process trying to take it (due to an open/read/write/&c.) will enter uninterruptible sleep. This also masks inconsistent wake-ups (usually every second line) when splicing from ttys in icanon mode. Link: https://lore.kernel.org/linux-fsdevel/CAHk-=wimmqG_wvSRtMiKPeGGDL816n65u=Mq2+H3-=uM2U6FmA@mail.gmail.com/ Signed-off-by: Ahelenia Ziemiańska Acked-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 06414e43e0b5..50c2957a9c7f 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -465,7 +465,6 @@ static const struct file_operations tty_fops = { .llseek = no_llseek, .read_iter = tty_read, .write_iter = tty_write, - .splice_read = copy_splice_read, .splice_write = iter_file_splice_write, .poll = tty_poll, .unlocked_ioctl = tty_ioctl, @@ -480,7 +479,6 @@ static const struct file_operations console_fops = { .llseek = no_llseek, .read_iter = tty_read, .write_iter = redirected_tty_write, - .splice_read = copy_splice_read, .splice_write = iter_file_splice_write, .poll = tty_poll, .unlocked_ioctl = tty_ioctl,