From patchwork Thu Sep 17 10:06:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 11782101 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 084DF59D for ; Thu, 17 Sep 2020 10:06:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E21C8208DB for ; Thu, 17 Sep 2020 10:06:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=suse.com header.i=@suse.com header.b="TFlhU1zZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726554AbgIQKGs (ORCPT ); Thu, 17 Sep 2020 06:06:48 -0400 Received: from mx2.suse.de ([195.135.220.15]:37708 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726559AbgIQKGf (ORCPT ); Thu, 17 Sep 2020 06:06:35 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=cantorsusede; t=1600337190; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=lAPuK4woBdNl3RoIv0cwrcWM2DcttdWFgRNJGM6HIXI=; b=TFlhU1zZGfB0hxAudWANKwucjCh54sFyz1e6vLmX5pQfJ8yEXmi6FrGTBBRk/0Dz+0DKWa T4yWUiWYTdFY0yShF7eg6bP1a/OeqVkTJDqmIYwpwGlNXIW3sLzbfLQSrJD7hNhh+FaUZ0 +M83YT4B33W8nCyBjV1dLkJJ/KLmivp4Wpcszpq6MUVjPV7D0XzFric5TBp0CaDVVhKEhM SvR5Ol8h5xtx1Z6sOuumQz4eQa4rX7J7lkZRgzIhA8yPyPjYtdXPhF8Suk2M7Zzijo+6sf QlP3oPQpTejpyl4zd9tPJr/NXEbTzTtQ0yqjjmKeeXIqGkKLGzB33efn3WQWyw== Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 625AEADEE; Thu, 17 Sep 2020 10:07:04 +0000 (UTC) From: Oliver Neukum To: penguin-kernel@i-love.sakura.ne.jp, bjorn@mork.no, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [RFC 7/7] CDC-WDM: implement fsync Date: Thu, 17 Sep 2020 12:06:14 +0200 Message-Id: <20200917100614.1010-8-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200917100614.1010-1-oneukum@suse.com> References: <20200917100614.1010-1-oneukum@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Some users want to be very sure that data has gone out to the device. This needs fsync. Reported-by: Tetsuo Handa Signed-off-by: Oliver Neukum --- drivers/usb/class/cdc-wdm.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index f952eec87b0f..7607ab2bbe07 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -590,6 +590,33 @@ static ssize_t wdm_read return rv; } +/* + * The difference to flush is that we wait forever. If you don't like + * that behavior, you need to send a signal. + */ + +static int wdm_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct wdm_device *desc = file->private_data; + int rv; + + rv = wait_event_interruptible(desc->wait, + !test_bit(WDM_IN_USE, &desc->flags) || + test_bit(WDM_DISCONNECTING, &desc->flags)); + + if (test_bit(WDM_DISCONNECTING, &desc->flags)) + return -ENODEV; + if (rv < 0) + return -EINTR; + + spin_lock_irq(&desc->iuspin); + rv = desc->werr; + desc->werr = 0; + spin_unlock_irq(&desc->iuspin); + + return usb_translate_errors(rv); +} + static int wdm_flush(struct file *file, fl_owner_t id) { struct wdm_device *desc = file->private_data; @@ -750,6 +777,7 @@ static const struct file_operations wdm_fops = { .owner = THIS_MODULE, .read = wdm_read, .write = wdm_write, + .fsync = wdm_fsync, .open = wdm_open, .flush = wdm_flush, .release = wdm_release,