From patchwork Fri Jan 18 21:32:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Wilck X-Patchwork-Id: 10771605 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E39DE6C2 for ; Fri, 18 Jan 2019 21:33:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D4995306B9 for ; Fri, 18 Jan 2019 21:33:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C2C62306E8; Fri, 18 Jan 2019 21:33:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 561763078E for ; Fri, 18 Jan 2019 21:33:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729791AbfARVdA (ORCPT ); Fri, 18 Jan 2019 16:33:00 -0500 Received: from smtp2.provo.novell.com ([137.65.250.81]:51676 "EHLO smtp2.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729672AbfARVc6 (ORCPT ); Fri, 18 Jan 2019 16:32:58 -0500 Received: from apollon.suse.de.de (prv-ext-foundry1int.gns.novell.com [137.65.251.240]) by smtp2.provo.novell.com with ESMTP (TLS encrypted); Fri, 18 Jan 2019 14:32:45 -0700 From: Martin Wilck To: Jens Axboe , Tejun Heo , Hannes Reinecke Cc: Martin Wilck , linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, linux-ide@vger.kernel.org, Christoph Hellwig , "Martin K. Petersen" , James Bottomley , Bart Van Assche Subject: [PATCH 4/4] block: check_events: don't bother with events if unsupported Date: Fri, 18 Jan 2019 22:32:07 +0100 Message-Id: <20190118213207.2309-5-mwilck@suse.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190118213207.2309-1-mwilck@suse.com> References: <20190118213207.2309-1-mwilck@suse.com> MIME-Version: 1.0 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Drivers now report to the block layer if they support media change events. If this is not the case, there's no need to allocate the event structure, and all event handling code can effectively be skipped. This simplifies code flow in particular for non-removable sd devices. This effectively reverts commit 75e3f3ee3c64 ("block: always allocate genhd->ev if check_events is implemented"). The sysfs files for the events are kept in place even if no events are supported, as user space may rely on them being present. The only difference is that an error code is now returned if the user tries to set poll_msecs. Signed-off-by: Martin Wilck Reviewed-by: Hannes Reinecke --- block/genhd.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index bcd16f6..55b6570 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1909,6 +1909,9 @@ static ssize_t disk_events_poll_msecs_show(struct device *dev, { struct gendisk *disk = dev_to_disk(dev); + if (!disk->ev) + return sprintf(buf, "-1\n"); + return sprintf(buf, "%ld\n", disk->ev->poll_msecs); } @@ -1925,6 +1928,9 @@ static ssize_t disk_events_poll_msecs_store(struct device *dev, if (intv < 0 && intv != -1) return -EINVAL; + if (!disk->ev) + return -ENODEV; + disk_block_events(disk); disk->ev->poll_msecs = intv; __disk_unblock_events(disk, true); @@ -1989,7 +1995,8 @@ static void disk_alloc_events(struct gendisk *disk) { struct disk_events *ev; - if (!disk->fops->check_events) + if (!disk->fops->check_events || + !(disk->events & DISK_EVENT_TYPES_MASK)) return; ev = kzalloc(sizeof(*ev), GFP_KERNEL); @@ -2011,14 +2018,14 @@ static void disk_alloc_events(struct gendisk *disk) static void disk_add_events(struct gendisk *disk) { - if (!disk->ev) - return; - /* FIXME: error handling */ if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0) pr_warn("%s: failed to create sysfs files for events\n", disk->disk_name); + if (!disk->ev) + return; + mutex_lock(&disk_events_mutex); list_add_tail(&disk->ev->node, &disk_events); mutex_unlock(&disk_events_mutex); @@ -2032,14 +2039,13 @@ static void disk_add_events(struct gendisk *disk) static void disk_del_events(struct gendisk *disk) { - if (!disk->ev) - return; + if (disk->ev) { + disk_block_events(disk); - disk_block_events(disk); - - mutex_lock(&disk_events_mutex); - list_del_init(&disk->ev->node); - mutex_unlock(&disk_events_mutex); + mutex_lock(&disk_events_mutex); + list_del_init(&disk->ev->node); + mutex_unlock(&disk_events_mutex); + } sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs); }