From patchwork Wed Mar 27 13:51:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Wilck X-Patchwork-Id: 10873521 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 4E48F1874 for ; Wed, 27 Mar 2019 13:52:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3ACFE28C34 for ; Wed, 27 Mar 2019 13:52:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 38F4228CFD; Wed, 27 Mar 2019 13:52:07 +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 A2D9F28BF5 for ; Wed, 27 Mar 2019 13:52:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730156AbfC0NwD (ORCPT ); Wed, 27 Mar 2019 09:52:03 -0400 Received: from smtp2.provo.novell.com ([137.65.250.81]:45637 "EHLO smtp2.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725797AbfC0NwA (ORCPT ); Wed, 27 Mar 2019 09:52:00 -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 07:51:49 -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 Subject: [PATCH v3 2/5] block: disk_events: introduce event flags Date: Wed, 27 Mar 2019 14:51:02 +0100 Message-Id: <20190327135105.30893-3-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 Currently, an empty disk->events field tells the block layer not to forward media change events to user space. This was done in commit 7c88a168da80 ("block: don't propagate unlisted DISK_EVENTs to userland") in order to avoid events from "fringe" drivers to be forwarded to user space. By doing so, the block layer lost the information which events were supported by a particular block device, and most importantly, whether or not a given device supports media change events at all. Prepare for not interpreting the "events" field this way in the future any more. This is done by adding an additional field "event_flags" to struct gendisk, and two flag bits that can be set to have the device treated like one that had the "events" field set to a non-zero value before. This applies only to the sd and sr drivers, which are changed to set the new flags. The new flags are DISK_EVENT_FLAG_POLL to enforce polling of the device for synchronous events, and DISK_EVENT_FLAG_UEVENT to tell the blocklayer to generate udev events from kernel events. In order to add the event_flags field to struct gendisk, the events field is converted to an "unsigned short"; it doesn't need to hold values bigger than 2 anyway. This patch doesn't change behavior. Signed-off-by: Martin Wilck Reviewed-by: Christoph Hellwig --- block/genhd.c | 13 +++++++++---- drivers/scsi/sd.c | 1 + drivers/scsi/sr.c | 1 + include/linux/genhd.h | 10 +++++++++- 4 files changed, 20 insertions(+), 5 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index ee76de0..5375be3 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1632,7 +1632,7 @@ static unsigned long disk_events_poll_jiffies(struct gendisk *disk) */ if (ev->poll_msecs >= 0) intv_msecs = ev->poll_msecs; - else if (disk->events) + else if (disk->event_flags & DISK_EVENT_FLAG_POLL) intv_msecs = disk_events_dfl_poll_msecs; return msecs_to_jiffies(intv_msecs); @@ -1842,11 +1842,13 @@ static void disk_check_events(struct disk_events *ev, /* * Tell userland about new events. Only the events listed in - * @disk->events are reported. Unlisted events are processed the - * same internally but never get reported to userland. + * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT + * is set. Otherwise, events are processed internally but never + * get reported to userland. */ for (i = 0; i < ARRAY_SIZE(disk_uevents); i++) - if (events & disk->events & (1 << i)) + if ((events & disk->events & (1 << i)) && + (disk->event_flags & DISK_EVENT_FLAG_UEVENT)) envp[nr_events++] = disk_uevents[i]; if (nr_events) @@ -1884,6 +1886,9 @@ static ssize_t disk_events_show(struct device *dev, { struct gendisk *disk = dev_to_disk(dev); + if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT)) + return 0; + return __disk_events_show(disk->events, buf); } diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 251db30..4742a22 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3327,6 +3327,7 @@ static void sd_probe_async(void *data, async_cookie_t cookie) if (sdp->removable) { gd->flags |= GENHD_FL_REMOVABLE; gd->events |= DISK_EVENT_MEDIA_CHANGE; + gd->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT; } blk_pm_runtime_init(sdp->request_queue, dev); diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 039c27c2..c3f443d 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -716,6 +716,7 @@ static int sr_probe(struct device *dev) disk->fops = &sr_bdops; disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE; disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST; + disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT; blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT); diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 5f78edb..081cb77 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -150,6 +150,13 @@ enum { DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */ }; +enum { + /* Poll even if events_poll_msecs is unset */ + DISK_EVENT_FLAG_POLL = 1 << 0, + /* Forward events to udev */ + DISK_EVENT_FLAG_UEVENT = 1 << 1, +}; + struct disk_part_tbl { struct rcu_head rcu_head; int len; @@ -184,7 +191,8 @@ struct gendisk { char disk_name[DISK_NAME_LEN]; /* name of major driver */ char *(*devnode)(struct gendisk *gd, umode_t *mode); - unsigned int events; /* supported events */ + unsigned short events; /* supported events */ + unsigned short event_flags; /* flags related to event processing */ /* Array of pointers to partitions indexed by partno. * Protected with matching bdev lock but stat and other