From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 2/2] ide: unexport DISK_EVENT_MEDIA_CHANGE for ide-gd and ide-cd Date: Thu, 21 Apr 2011 19:09:25 +0200 Message-ID: <20110421170925.GD15988@htj.dyndns.org> References: <20110421170826.GC15988@htj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:58801 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754914Ab1DURJ3 (ORCPT ); Thu, 21 Apr 2011 13:09:29 -0400 Content-Disposition: inline In-Reply-To: <20110421170826.GC15988@htj.dyndns.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jens Axboe Cc: Linus Torvalds , Christoph Hellwig , Neil Brown , "David S. Miller" , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, kay.sievers@vrfy.org check_events() implementations in both ide-gd and ide-cd are inadequate for in-kernel event polling. Both generate media change events continuously when certain conditions are met causing infinite event loop between the driver and userland event handler. As disk event now supports suppression of unlisted events, simply de-listing DISK_EVENT_MEDIA_CHANGE from disk->events resolves the problem. Internal handling around media revalidation will behave the same while userland will fall back to userland event polling after detecting the device doesn't support disk events. Signed-off-by: Tejun Heo Reported-by: Jens Axboe Cc: "David S. Miller" --- drivers/ide/ide-cd.c | 1 - drivers/ide/ide-cd_ioctl.c | 6 ++++++ drivers/ide/ide-gd.c | 7 ++++++- 3 files changed, 12 insertions(+), 2 deletions(-) Index: work/drivers/ide/ide-gd.c =================================================================== --- work.orig/drivers/ide/ide-gd.c +++ work/drivers/ide/ide-gd.c @@ -298,6 +298,12 @@ static unsigned int ide_gd_check_events( return 0; } + /* + * The following is used to force revalidation on the first open on + * removeable devices, and never gets reported to userland as + * genhd->events is 0. This is intended as removeable ide disk + * can't really detect MEDIA_CHANGE events. + */ ret = drive->dev_flags & IDE_DFLAG_MEDIA_CHANGED; drive->dev_flags &= ~IDE_DFLAG_MEDIA_CHANGED; @@ -413,7 +419,6 @@ static int ide_gd_probe(ide_drive_t *dri if (drive->dev_flags & IDE_DFLAG_REMOVABLE) g->flags = GENHD_FL_REMOVABLE; g->fops = &ide_gd_ops; - g->events = DISK_EVENT_MEDIA_CHANGE; add_disk(g); return 0; Index: work/drivers/ide/ide-cd.c =================================================================== --- work.orig/drivers/ide/ide-cd.c +++ work/drivers/ide/ide-cd.c @@ -1782,7 +1782,6 @@ static int ide_cd_probe(ide_drive_t *dri ide_cd_read_toc(drive, &sense); g->fops = &idecd_ops; g->flags |= GENHD_FL_REMOVABLE; - g->events = DISK_EVENT_MEDIA_CHANGE; add_disk(g); return 0; Index: work/drivers/ide/ide-cd_ioctl.c =================================================================== --- work.orig/drivers/ide/ide-cd_ioctl.c +++ work/drivers/ide/ide-cd_ioctl.c @@ -79,6 +79,12 @@ int ide_cdrom_drive_status(struct cdrom_ return CDS_DRIVE_NOT_READY; } +/* + * ide-cd always generates media changed event if media is missing, which + * makes it impossible to use for proper event reporting, so disk->events + * is cleared to 0 and the following function is used only to trigger + * revalidation and never propagated to userland. + */ unsigned int ide_cdrom_check_events_real(struct cdrom_device_info *cdi, unsigned int clearing, int slot_nr) {