From patchwork Fri Apr 25 11:13:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 885434 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 C7D18240604; Fri, 25 Apr 2025 11:13:20 +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=1745579600; cv=none; b=LUysVKE5PVC1yIsz98kGKESQv2iFyxUc/LltU10b4y4KKVwv4TY8sk8PLJARiJXiWRQgc1iw1kdBRZYmhEW9BDwkHlGkmuAmgaEkt9dIQYxd0/pQbnyW4D0p8ZwY0eyWqJp+EitBrw0N0QMDjCiJlM8yXzL7qqKxnnq0C1DBLrE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745579600; c=relaxed/simple; bh=c3F1gW9ZPCR5oHtLAFds0q5hpGxchQa902GwA8/ZnVg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oN8I2kGEt6Bb6Dd9xhUH5lytg7YEc7FseEE2NwcZ70bAHrN7vWouTmBJ+Ug7rOtKYj69HZ8CaY9bfzvOhmAoYpnQWsmCVB7ETvc11wkxtTGSRTBruSjlhkVyHAR4cS04D0xm5ExecvNMrxFa+1ZqWtfbqXRg8Wx3ByNYP91Bgac= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lbvtIGdY; 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="lbvtIGdY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3BD83C4CEEB; Fri, 25 Apr 2025 11:13:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745579600; bh=c3F1gW9ZPCR5oHtLAFds0q5hpGxchQa902GwA8/ZnVg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lbvtIGdYxF4RFuOhlej2+RLOUz7SFQ9JsUnKoUHFceBhcL0f94AtmbtNOXrkxJpob xjJbRz7zCzO/nTy+j++nTSVAr+XuDvJmyQAsZkwHw3tKQyiQsKTzo6zUMZ+jHYPZvm Gs2aoGXwSL0I0ohYHJnm7FBRlfkrD30wEpz1iVmz3f0Jv94Nbpu1lfPb4mOnydZmQJ uNhpUrBGh3o3yA6xQnXSL6bNPttwwcSvbdVhCcUEFz91+3wXEIhfMm3FmpYslRqxeF wFFEHLjcwpMeOqugXDtKQMuvy/66t3wtX7hFn0M+/QOvS/pSARt4hfQmWdlk9T4gZi +QjfE1lFQG85A== From: "Jiri Slaby (SUSE)" To: gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, "Jiri Slaby (SUSE)" Subject: [PATCH 1/6] tty: simplify throttling using guard()s Date: Fri, 25 Apr 2025 13:13:10 +0200 Message-ID: <20250425111315.1036184-2-jirislaby@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250425111315.1036184-1-jirislaby@kernel.org> References: <20250425111315.1036184-1-jirislaby@kernel.org> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 tty_throttle_safe() and tty_unthrottle_safe can be made less convoluted using guard()s. Switch them. Signed-off-by: Jiri Slaby (SUSE) --- drivers/tty/tty_ioctl.c | 50 +++++++++++++++++++---------------------- 1 file changed, 23 insertions(+), 27 deletions(-) diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index 85de90eebc7b..90c70d8d14e3 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -122,21 +122,19 @@ EXPORT_SYMBOL(tty_unthrottle); */ bool tty_throttle_safe(struct tty_struct *tty) { - bool ret = true; - - mutex_lock(&tty->throttle_mutex); - if (!tty_throttled(tty)) { - if (tty->flow_change != TTY_THROTTLE_SAFE) - ret = false; - else { - set_bit(TTY_THROTTLED, &tty->flags); - if (tty->ops->throttle) - tty->ops->throttle(tty); - } - } - mutex_unlock(&tty->throttle_mutex); + guard(mutex)(&tty->throttle_mutex); - return ret; + if (tty_throttled(tty)) + return true; + + if (tty->flow_change != TTY_THROTTLE_SAFE) + return false; + + set_bit(TTY_THROTTLED, &tty->flags); + if (tty->ops->throttle) + tty->ops->throttle(tty); + + return true; } /** @@ -152,21 +150,19 @@ bool tty_throttle_safe(struct tty_struct *tty) */ bool tty_unthrottle_safe(struct tty_struct *tty) { - bool ret = true; + guard(mutex)(&tty->throttle_mutex); - mutex_lock(&tty->throttle_mutex); - if (tty_throttled(tty)) { - if (tty->flow_change != TTY_UNTHROTTLE_SAFE) - ret = false; - else { - clear_bit(TTY_THROTTLED, &tty->flags); - if (tty->ops->unthrottle) - tty->ops->unthrottle(tty); - } - } - mutex_unlock(&tty->throttle_mutex); + if (!tty_throttled(tty)) + return true; - return ret; + if (tty->flow_change != TTY_UNTHROTTLE_SAFE) + return false; + + clear_bit(TTY_THROTTLED, &tty->flags); + if (tty->ops->unthrottle) + tty->ops->unthrottle(tty); + + return true; } /**