From patchwork Wed Oct 9 02:02:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vito Caputo X-Patchwork-Id: 11180243 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9CC7276 for ; Wed, 9 Oct 2019 02:08:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88BE921835 for ; Wed, 9 Oct 2019 02:08:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729644AbfJICIH (ORCPT ); Tue, 8 Oct 2019 22:08:07 -0400 Received: from shells.gnugeneration.com ([66.240.222.126]:37540 "EHLO shells.gnugeneration.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726109AbfJICIH (ORCPT ); Tue, 8 Oct 2019 22:08:07 -0400 X-Greylist: delayed 362 seconds by postgrey-1.27 at vger.kernel.org; Tue, 08 Oct 2019 22:08:07 EDT Received: by shells.gnugeneration.com (Postfix, from userid 1000) id 809B51A40559; Tue, 8 Oct 2019 19:02:05 -0700 (PDT) Date: Tue, 8 Oct 2019 19:02:05 -0700 From: Vito Caputo To: viro@zeniv.linux.org.uk Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] seq_file: move seq_read() flushing into a function Message-ID: <20191009020205.2ezkdwzisnhtoau4@shells.gnugeneration.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Consolidate some duplicated bookkeeping from seq_read() into a function. Signed-off-by: Vito Caputo --- fs/seq_file.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) diff --git a/fs/seq_file.c b/fs/seq_file.c index 1600034a929b..e5d2bccf5ac4 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -141,6 +141,25 @@ static int traverse(struct seq_file *m, loff_t offset) return !m->buf ? -ENOMEM : -EAGAIN; } +static int flush(struct seq_file *m, char __user **buf, size_t *size, size_t *copied) +{ + int err = 0; + size_t n; + + if (!m->count) + return err; + n = min(m->count, *size); + err = copy_to_user(*buf, m->buf + m->from, n); + if (err) + return err; + m->count -= n; + m->from += n; + *size -= n; + *buf += n; + *copied += n; + return err; +} + /** * seq_read - ->read() method for sequential files. * @file: the file to read from @@ -154,7 +173,6 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) { struct seq_file *m = file->private_data; size_t copied = 0; - size_t n; void *p; int err = 0; @@ -207,15 +225,9 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) } /* if not empty - flush it first */ if (m->count) { - n = min(m->count, size); - err = copy_to_user(buf, m->buf + m->from, n); + err = flush(m, &buf, &size, &copied); if (err) goto Efault; - m->count -= n; - m->from += n; - size -= n; - buf += n; - copied += n; if (!size) goto Done; } @@ -273,13 +285,9 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) } } m->op->stop(m, p); - n = min(m->count, size); - err = copy_to_user(buf, m->buf, n); + err = flush(m, &buf, &size, &copied); if (err) goto Efault; - copied += n; - m->count -= n; - m->from = n; Done: if (!copied) copied = err;