From patchwork Fri Mar 22 22:43:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Wilck X-Patchwork-Id: 10866587 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 5D12113B5 for ; Fri, 22 Mar 2019 22:45:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4DE3A2A595 for ; Fri, 22 Mar 2019 22:45:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 41F6E2A770; Fri, 22 Mar 2019 22:45:22 +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=unavailable 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 860D42A75D for ; Fri, 22 Mar 2019 22:45:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728387AbfCVWpK (ORCPT ); Fri, 22 Mar 2019 18:45:10 -0400 Received: from smtp2.provo.novell.com ([137.65.250.81]:52220 "EHLO smtp2.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728309AbfCVWpI (ORCPT ); Fri, 22 Mar 2019 18:45:08 -0400 Received: from apollon.suse.de.de (prva10-snat226-1.provo.novell.com [137.65.226.35]) by smtp2.provo.novell.com with ESMTP (TLS encrypted); Fri, 22 Mar 2019 16:44:57 -0600 From: Martin Wilck To: Jens Axboe , Tejun Heo , Hannes Reinecke , "Martin K. Petersen" Cc: James Bottomley , Christoph Hellwig , Bart Van Assche , Martin Wilck , linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org Subject: [PATCH RESEND v2 5/5] block: check_events: don't bother with events if unsupported Date: Fri, 22 Mar 2019 23:43:53 +0100 Message-Id: <20190322224353.11088-6-mwilck@suse.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190322224353.11088-1-mwilck@suse.com> References: <20190322224353.11088-1-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 Reviewed-by: Christoph Hellwig --- block/genhd.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index cc6c52d1..0eda20b 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1904,6 +1904,9 @@ 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); } @@ -1920,6 +1923,9 @@ 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); @@ -1984,7 +1990,8 @@ 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); @@ -2006,14 +2013,14 @@ 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); @@ -2027,14 +2034,13 @@ 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); }