From 9fd097b14918875bd6f125ed699d7bbbba5893ee Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 21 Apr 2011 21:32:55 +0200 Subject: block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe drivers In-kernel disk event polling doesn't matter for legacy/fringe drivers and may lead to infinite event loop if ->check_events() implementation generates events on level condition instead of edge. Now that block layer supports suppressing exporting unlisted events, simply leaving disk->events cleared allows these drivers to keep the internal revalidation behavior intact while avoiding weird interactions with userland event handler. Signed-off-by: Tejun Heo Cc: Kay Sievers Signed-off-by: Jens Axboe --- drivers/cdrom/gdrom.c | 1 - drivers/cdrom/viocd.c | 1 - 2 files changed, 2 deletions(-) (limited to 'drivers/cdrom') diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c index b2b034fea34..3ceaf006e7f 100644 --- a/drivers/cdrom/gdrom.c +++ b/drivers/cdrom/gdrom.c @@ -803,7 +803,6 @@ static int __devinit probe_gdrom(struct platform_device *devptr) goto probe_fail_cdrom_register; } gd.disk->fops = &gdrom_bdops; - gd.disk->events = DISK_EVENT_MEDIA_CHANGE; /* latch on to the interrupt */ err = gdrom_set_interrupt_handlers(); if (err) diff --git a/drivers/cdrom/viocd.c b/drivers/cdrom/viocd.c index 4e874c5fa60..e427fbe4599 100644 --- a/drivers/cdrom/viocd.c +++ b/drivers/cdrom/viocd.c @@ -626,7 +626,6 @@ static int viocd_probe(struct vio_dev *vdev, const struct vio_device_id *id) gendisk->queue = q; gendisk->fops = &viocd_fops; gendisk->flags = GENHD_FL_CD|GENHD_FL_REMOVABLE; - gendisk->events = DISK_EVENT_MEDIA_CHANGE; set_capacity(gendisk, 0); gendisk->private_data = d; d->viocd_disk = gendisk; -- cgit v1.2.3-18-g5258 From bf2253a6f00e8fea5b026e471e9f0d0a1b3621f2 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 29 Apr 2011 10:15:14 +0200 Subject: cdrom: always check_disk_change() on open cdrom_open() called check_disk_change() after the rest of open path succeeded which leads to the following bizarre behavior. * After media change, if the device opened without O_NONBLOCK, open_for_data() naturally fails with -ENOMEDIA and check_disk_change() is never called. The media is known to be gone and the open failure makes it obvious to the userland but device invalidation never happens. * But if the device is opened with O_NONBLOCK, all the checks are bypassed and cdrom_open() doesn't notice that the media is not there and check_disk_change() is called and invalidation happens. There's nothing to be gained by avoiding calling check_disk_change() on open failure. Common cases end up calling check_disk_change() anyway. All we get is inconsistent behavior. Fix it by moving check_disk_change() invocation to the top of cdrom_open() so that it always gets called regardless of how the rest of open proceeds. Stable: 2.6.38 Signed-off-by: Tejun Heo Reported-by: Amit Shah Tested-by: Amit Shah Cc: stable@kernel.org Signed-off-by: Jens Axboe --- drivers/cdrom/cdrom.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/cdrom') diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c index 514dd8efaf7..75fb965b8f7 100644 --- a/drivers/cdrom/cdrom.c +++ b/drivers/cdrom/cdrom.c @@ -986,6 +986,9 @@ int cdrom_open(struct cdrom_device_info *cdi, struct block_device *bdev, fmode_t cdinfo(CD_OPEN, "entering cdrom_open\n"); + /* open is event synchronization point, check events first */ + check_disk_change(bdev); + /* if this was a O_NONBLOCK open and we should honor the flags, * do a quick open without drive/disc integrity checks. */ cdi->use_count++; @@ -1012,9 +1015,6 @@ int cdrom_open(struct cdrom_device_info *cdi, struct block_device *bdev, fmode_t cdinfo(CD_OPEN, "Use count for \"/dev/%s\" now %d\n", cdi->name, cdi->use_count); - /* Do this on open. Don't wait for mount, because they might - not be mounting, but opening with O_NONBLOCK */ - check_disk_change(bdev); return 0; err_release: if (CDROM_CAN(CDC_LOCK) && cdi->options & CDO_LOCK) { -- cgit v1.2.3-18-g5258