From patchwork Mon Mar 17 07:00:22 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 874689 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 7D37521C16E; Mon, 17 Mar 2025 07:01:01 +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=1742194861; cv=none; b=Q40AGFU+gmKvT3ru3i2Ry5TOr2xcuaoAoqBNOwFM8Vd8RTXBtpJfY9v44mBQxbzFDyQYkrPdixzSVZH8u698w0YAAiX8eH3XtcSQ61G0a76Yn8CLmR7xt8D0bBniULUMEa7/wliAZKyLX1nJlGKgxlQZ5xlq3PT647HWDpq8p8s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742194861; c=relaxed/simple; bh=plurQo8sBiuqrUN+GnUsQOZRDBrXhR0tlCQG5LFRAKc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mzuBARsWUr6AIVkXTLi3gFnGjzzPts0MkRbhHJb6ooH1oFsJjreezQ3mgN7n8OtjwPr903g4ztnB4rSiciMro8yOgZqlwOBbmcyifdxIA2JVIkfO0rJIiS19XujLMTBsynplC4TvN9a8zjbIccu1R5lgnltN6CEG/MBkQPY1YBk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SRoKbbPn; 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="SRoKbbPn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38704C4CEE3; Mon, 17 Mar 2025 07:01:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742194861; bh=plurQo8sBiuqrUN+GnUsQOZRDBrXhR0tlCQG5LFRAKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SRoKbbPnALW504MG+5RnseH4/paOqI1lY//iK62PklHZzWqqqAxnVtl0+Jsl26D5y cWv7MkfEcIbZ0IrRfOVVaHDsIeDRZH7jWQ//oRciU41/P2azZRhHC1qyt3P9swm0nM RqwOE/MzIopMWBIlLXuvyrjjspvvCOAlsz3pT5j6TgTM+VcbTR/SYUWdsK9PE4Jy90 K1Cp9CfeL+Tb2c23uWYthbJijn9HHhRoNaUpe4UqwcvtgLSmVv8rIh4roKxxtFwAKG nFaaSX5K51yahXchwMK7ka+3d6itkslVCvJtqxKzDkY9Jzh02Ya2v8YCvVCsPkTmo2 I6QQTVYTmzYRw== 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 07/31] tty: n_tty: clean up process_output_block() Date: Mon, 17 Mar 2025 08:00:22 +0100 Message-ID: <20250317070046.24386-8-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 * Use guard(mutex), which results in: - the function can return directly when "space == 0". - "i" can now be "unsigned" as it is no longer abused to hold a retval from tty->ops->write(). Note the compared-to "nr" is already "unsigned". * The end label is now dubbed "do_write" as that is what happens there. Unlike the uncertain "break_out" name. Signed-off-by: Jiri Slaby (SUSE) --- drivers/tty/n_tty.c | 27 +++++++++++---------------- 1 file changed, 11 insertions(+), 16 deletions(-) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index df52aae5f71a..5d172edbb03c 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -519,17 +519,15 @@ static ssize_t process_output_block(struct tty_struct *tty, const u8 *buf, unsigned int nr) { struct n_tty_data *ldata = tty->disc_data; - unsigned int space; - int i; + unsigned int space, i; const u8 *cp; - mutex_lock(&ldata->output_lock); + guard(mutex)(&ldata->output_lock); space = tty_write_room(tty); - if (space == 0) { - mutex_unlock(&ldata->output_lock); + if (space == 0) return 0; - } + if (nr > space) nr = space; @@ -541,18 +539,18 @@ static ssize_t process_output_block(struct tty_struct *tty, if (O_ONLRET(tty)) ldata->column = 0; if (O_ONLCR(tty)) - goto break_out; + goto do_write; ldata->canon_column = ldata->column; break; case '\r': if (O_ONOCR(tty) && ldata->column == 0) - goto break_out; + goto do_write; if (O_OCRNL(tty)) - goto break_out; + goto do_write; ldata->canon_column = ldata->column = 0; break; case '\t': - goto break_out; + goto do_write; case '\b': if (ldata->column > 0) ldata->column--; @@ -560,18 +558,15 @@ static ssize_t process_output_block(struct tty_struct *tty, default: if (!iscntrl(c)) { if (O_OLCUC(tty)) - goto break_out; + goto do_write; if (!is_continuation(c, tty)) ldata->column++; } break; } } -break_out: - i = tty->ops->write(tty, buf, i); - - mutex_unlock(&ldata->output_lock); - return i; +do_write: + return tty->ops->write(tty, buf, i); } static int n_tty_process_echo_ops(struct tty_struct *tty, size_t *tail,