From patchwork Wed Mar 27 13:51:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Wilck X-Patchwork-Id: 10873527 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 8B5511874 for ; Wed, 27 Mar 2019 13:52:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7B84828C18 for ; Wed, 27 Mar 2019 13:52:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 785E528C2A; Wed, 27 Mar 2019 13:52:11 +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 223D428C18 for ; Wed, 27 Mar 2019 13:52:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730255AbfC0NwK (ORCPT ); Wed, 27 Mar 2019 09:52:10 -0400 Received: from smtp2.provo.novell.com ([137.65.250.81]:59107 "EHLO smtp2.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726233AbfC0NwK (ORCPT ); Wed, 27 Mar 2019 09:52:10 -0400 Received: from apollon.suse.de.de (prva10-snat226-2.provo.novell.com [137.65.226.36]) by smtp2.provo.novell.com with ESMTP (TLS encrypted); Wed, 27 Mar 2019 07:51:57 -0600 From: Martin Wilck To: Jens Axboe , Tejun Heo , Hannes Reinecke , "Martin K. Petersen" , Christoph Hellwig Cc: James Bottomley , Bart Van Assche , Martin Wilck , linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, Hannes Reinecke Subject: [PATCH v3 5/5] block: check_events: don't bother with events if unsupported Date: Wed, 27 Mar 2019 14:51:05 +0100 Message-Id: <20190327135105.30893-6-mwilck@suse.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190327135105.30893-1-mwilck@suse.com> References: <20190327135105.30893-1-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. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Martin Wilck --- block/genhd.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 5375be3..1d0d25f 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 +1990,7 @@ static void disk_alloc_events(struct gendisk *disk) { struct disk_events *ev; - if (!disk->fops->check_events) + if (!disk->fops->check_events || !disk->events) return; ev = kzalloc(sizeof(*ev), GFP_KERNEL); @@ -2006,14 +2012,14 @@ 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 +2033,13 @@ 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); }