From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 377EDC433FE for ; Sat, 4 Sep 2021 06:01:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19284610A1 for ; Sat, 4 Sep 2021 06:01:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232568AbhIDGCp (ORCPT ); Sat, 4 Sep 2021 02:02:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:58642 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229741AbhIDGCo (ORCPT ); Sat, 4 Sep 2021 02:02:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0F21260F56; Sat, 4 Sep 2021 06:01:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1630735303; bh=SrDxuptF3EM7MY1cjNB3mCBrnNxv5wMFsvQMgUyB3bY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VS/BplqC9kTTm4G7UKDbbRH0vIGFT/8bBxMwQBkFiAYIV0Nqsl62HTzCvkFLuoGOy JbVlIu/AIA+B21B4nJnWRFDC+JIjhL9Emt22A8Ww/IlcLYIKj56L9S8ITk3dbOEYld rQr/1yDNwzXeKpT2W8le+SqzPUA+sImHb3jJKAeA= Date: Sat, 4 Sep 2021 08:01:41 +0200 From: Greg KH To: Ian Pilcher Cc: axboe@kernel.dk, pavel@ucw.cz, linux-leds@vger.kernel.org, linux-block@vger.kernel.org, linux@vger.kernel.org, kabel@kernel.org Subject: Re: [PATCH 09/18] ledtrig-blkdev: Periodically check devices for activity & blink LEDs Message-ID: References: <20210903204548.2745354-1-arequipeno@gmail.com> <20210903204548.2745354-10-arequipeno@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210903204548.2745354-10-arequipeno@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Sep 03, 2021 at 03:45:39PM -0500, Ian Pilcher wrote: > Use a delayed workqueue to periodically check configured block devices for > activity since the last check. Blink LEDs associated with devices on which > the configured type of activity (read/write) has occurred. > > Signed-off-by: Ian Pilcher > --- > drivers/leds/trigger/ledtrig-blkdev.c | 88 +++++++++++++++++++++++++++ > 1 file changed, 88 insertions(+) > > diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c > index 1f319529c3be..37ba9bb3542e 100644 > --- a/drivers/leds/trigger/ledtrig-blkdev.c > +++ b/drivers/leds/trigger/ledtrig-blkdev.c > @@ -7,7 +7,9 @@ > */ > > #include > +#include > #include > +#include > > #include "ledtrig-blkdev.h" > > @@ -68,6 +70,10 @@ static unsigned int ledtrig_blkdev_count; > /* How often to check for drive activity - in jiffies */ > static unsigned int ledtrig_blkdev_interval; > > +/* Delayed work used to periodically check for activity & blink LEDs */ > +static void blkdev_process(struct work_struct *const work); > +static DECLARE_DELAYED_WORK(ledtrig_blkdev_work, blkdev_process); > + > > /* > * > @@ -110,3 +116,85 @@ static bool blkdev_write_mode(const enum ledtrig_blkdev_mode mode) > { > return mode != LEDTRIG_BLKDEV_MODE_RO; > } > + > + > +/* > + * > + * Periodically check for device acitivity and blink LEDs > + * > + */ > + > +static void blkdev_blink(const struct ledtrig_blkdev_led *const led) > +{ > + unsigned long delay_on = READ_ONCE(led->blink_msec); > + unsigned long delay_off = 1; /* 0 leaves LED turned on */ > + > + led_blink_set_oneshot(led->led_dev, &delay_on, &delay_off, 0); > +} > + > +static void blkdev_update_disk(struct ledtrig_blkdev_disk *const disk, > + const unsigned int generation) > +{ > + const struct block_device *const part0 = disk->gd->part0; > + const unsigned long read_ios = part_stat_read(part0, ios[STAT_READ]); > + const unsigned long write_ios = part_stat_read(part0, ios[STAT_WRITE]) > + + part_stat_read(part0, ios[STAT_DISCARD]) > + + part_stat_read(part0, ios[STAT_FLUSH]); > + > + if (disk->read_ios != read_ios) { > + disk->read_act = true; > + disk->read_ios = read_ios; > + } else { > + disk->read_act = false; > + } > + > + if (disk->write_ios != write_ios) { > + disk->write_act = true; > + disk->write_ios = write_ios; > + } else { > + disk->write_act = false; > + } > + > + disk->generation = generation; > +} > + > +static void blkdev_process(struct work_struct *const work) > +{ > + static unsigned int generation; > + > + struct ledtrig_blkdev_led *led; > + struct ledtrig_blkdev_link *link; > + unsigned long delay; > + > + if (!mutex_trylock(&ledtrig_blkdev_mutex)) > + goto exit_reschedule; > + > + hlist_for_each_entry(led, &ledtrig_blkdev_leds, leds_node) { > + > + hlist_for_each_entry(link, &led->disks, led_disks_node) { > + > + struct ledtrig_blkdev_disk *const disk = link->disk; > + > + if (disk->generation != generation) > + blkdev_update_disk(disk, generation); > + > + if (disk->read_act && blkdev_read_mode(led->mode)) { > + blkdev_blink(led); > + break; > + } > + > + if (disk->write_act && blkdev_write_mode(led->mode)) { > + blkdev_blink(led); > + break; > + } > + } > + } > + > + ++generation; > + > + mutex_unlock(&ledtrig_blkdev_mutex); > + > +exit_reschedule: > + delay = READ_ONCE(ledtrig_blkdev_interval); > + WARN_ON_ONCE(!schedule_delayed_work(&ledtrig_blkdev_work, delay)); You just rebooted a machine if it hit this :( Please never use WARN_ON() in new code unless the machine is really broken and you can not do anything else here. thanks, greg k-h