block: don't block events on excl write for non-optical devices

Disk event code automatically blocks events on excl write.  This is
primarily to avoid issuing polling commands while burning is in
progress.  This behavior doesn't fit other types of devices with
removeable media where polling commands don't have adverse side
effects and door locking usually doesn't exist.

This patch introduces new genhd flag which controls the auto-blocking
behavior and uses it to enable auto-blocking only on optical devices.

Note for stable: 2.6.38 and later only

Cc: stable@kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/cdrom/viocd.c b/drivers/cdrom/viocd.c
index 4e874c5fa605..ae15a4ddaa9b 100644
--- a/drivers/cdrom/viocd.c
+++ b/drivers/cdrom/viocd.c
@@ -625,7 +625,8 @@ static int viocd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
         blk_queue_max_hw_sectors(q, 4096 / 512);
         gendisk->queue = q;
         gendisk->fops = &viocd_fops;
-        gendisk->flags = GENHD_FL_CD|GENHD_FL_REMOVABLE;
+        gendisk->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE |
+                         GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
         gendisk->events = DISK_EVENT_MEDIA_CHANGE;
         set_capacity(gendisk, 0);
         gendisk->private_data = d;