From patchwork Mon Mar 17 07:00:25 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 874329 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 00F6821CA13; Mon, 17 Mar 2025 07:01:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742194866; cv=none; b=L5Eux1PrCFrB2DcYoRVM2QkFqbWT+dyS+667Ozq0T7rSOnWfzcQACCE0/oiIKlAPVErI518Ax9/NZejYSYYl2krpYj6tW9nyLJjSwwpSwQnMI3KIi//5WaToSTpdps/VO8NprM27zE6NSgTehbHrUT/EEQDKCNoOIqtXw6gWLJQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742194866; c=relaxed/simple; bh=KtXCMXaczl+E79GCAttWES8YpJxjKFSJ1NhubZhJFVM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lQIzdwuEasWPyYfiQisvKvTPB+KyNaPsCsMWl42qby6hSSZPSPCzlmEGQPL0t+hgZf+9o4xG1UvEIbNqJzfXycshclXrcXZLhFSsOouNlefGxbDg3WM+RGK8HxB3cGmNvGf39x4uRvi3zrSgLcGsWdx5ui634cqiEEPgwmZLqt4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mNIdubXG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mNIdubXG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF0AAC4CEF0; Mon, 17 Mar 2025 07:01:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742194865; bh=KtXCMXaczl+E79GCAttWES8YpJxjKFSJ1NhubZhJFVM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mNIdubXGnt2oPQVpmUU6XwMKsOKaPBLqU7f9asvtV1B1/Gq3MVzsQWSzRTdJ7+cTS OhXbyGh9gkMD2w2FcSwrIBdb4ukY9D0a3hr+xzdA/H7A6XZkboZhxSqfSuBNoYxAMp 8EJgMSz/dQbv8ScimjWgRGiWXQo1fPuBlg0b8/U06m5oTCFgcsiwPtofucMfeSS6tk oSL73g2ZWeUOfIGHjmAb62GKw5Ug2tLyHHoHFIvod1VSJP8y2I9VvtAq5rXdkagJwG i0MpgkZwGKGIAPH5xxijFfhYWcGCH0PDK60zQSmUdXHCiyJb47ltP5AtMe+1fvG2TA W1LH5AcWvvapA== From: "Jiri Slaby (SUSE)" To: gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, "Jiri Slaby (SUSE)" Subject: [PATCH v2 10/31] tty: n_tty: extract n_tty_wait_for_input() Date: Mon, 17 Mar 2025 08:00:25 +0100 Message-ID: <20250317070046.24386-11-jirislaby@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250317070046.24386-1-jirislaby@kernel.org> References: <20250317070046.24386-1-jirislaby@kernel.org> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 n_tty_read() is a very long function doing too much of different stuff. Extract the "wait for input" to a separate function: n_tty_wait_for_input(). It returns an error (< 0), no input (0), or has potential input (1). Signed-off-by: Jiri Slaby (SUSE) --- drivers/tty/n_tty.c | 57 ++++++++++++++++++++++++--------------------- 1 file changed, 31 insertions(+), 26 deletions(-) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 88aa5f9cbe5e..0e3eb18490f0 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -2145,6 +2145,33 @@ static ssize_t n_tty_continue_cookie(struct tty_struct *tty, u8 *kbuf, return kb - kbuf; } +static int n_tty_wait_for_input(struct tty_struct *tty, struct file *file, + struct wait_queue_entry *wait, long *timeout) +{ + if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) + return -EIO; + if (tty_hung_up_p(file)) + return 0; + /* + * Abort readers for ttys which never actually get hung up. + * See __tty_hangup(). + */ + if (test_bit(TTY_HUPPING, &tty->flags)) + return 0; + if (!*timeout) + return 0; + if (tty_io_nonblock(tty, file)) + return -EAGAIN; + if (signal_pending(current)) + return -ERESTARTSYS; + + up_read(&tty->termios_rwsem); + *timeout = wait_woken(wait, TASK_INTERRUPTIBLE, *timeout); + down_read(&tty->termios_rwsem); + + return 1; +} + /** * n_tty_read - read function for tty * @tty: tty device @@ -2234,34 +2261,12 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf, tty_buffer_flush_work(tty->port); down_read(&tty->termios_rwsem); if (!input_available_p(tty, 0)) { - if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { - retval = -EIO; + int ret = n_tty_wait_for_input(tty, file, &wait, + &timeout); + if (ret <= 0) { + retval = ret; break; } - if (tty_hung_up_p(file)) - break; - /* - * Abort readers for ttys which never actually - * get hung up. See __tty_hangup(). - */ - if (test_bit(TTY_HUPPING, &tty->flags)) - break; - if (!timeout) - break; - if (tty_io_nonblock(tty, file)) { - retval = -EAGAIN; - break; - } - if (signal_pending(current)) { - retval = -ERESTARTSYS; - break; - } - up_read(&tty->termios_rwsem); - - timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, - timeout); - - down_read(&tty->termios_rwsem); continue; } }