From patchwork Tue Feb 5 11:37:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Wilck X-Patchwork-Id: 10797401 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 E4A401669 for ; Tue, 5 Feb 2019 11:38:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D36C52AD94 for ; Tue, 5 Feb 2019 11:38:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C7CE92B403; Tue, 5 Feb 2019 11:38:29 +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 697872B398 for ; Tue, 5 Feb 2019 11:38:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729005AbfBELi2 (ORCPT ); Tue, 5 Feb 2019 06:38:28 -0500 Received: from smtp2.provo.novell.com ([137.65.250.81]:52012 "EHLO smtp2.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728937AbfBELi2 (ORCPT ); Tue, 5 Feb 2019 06:38:28 -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); Tue, 05 Feb 2019 04:38:17 -0700 From: Martin Wilck To: Jens Axboe , Tejun Heo , Hannes Reinecke Cc: Christoph Hellwig , James Bottomley , "Martin K. Petersen" , Bart Van Assche , Martin Wilck , linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org Subject: [PATCH v2 5/5] block: check_events: don't bother with events if unsupported Date: Tue, 5 Feb 2019 12:37:41 +0100 Message-Id: <20190205113741.11267-6-mwilck@suse.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190205113741.11267-1-mwilck@suse.com> References: <20190205113741.11267-1-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 --- block/genhd.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 7f5a370..6cc1dfd 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1902,6 +1902,9 @@ 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); } @@ -1918,6 +1921,9 @@ 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); @@ -1982,7 +1988,8 @@ 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); @@ -2004,14 +2011,14 @@ 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); @@ -2025,14 +2032,13 @@ 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); }