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>

4 files changed, 5 insertions, 3 deletions

diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index 2f2ccf686251..a0aabd904a51 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -320,6 +320,7 @@ static void pcd_init_units(void)
                 disk->first_minor = unit;
                 strcpy(disk->disk_name, cd->name);      /* umm... */
                 disk->fops = &pcd_bdops;
+                disk->flags = GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
                 disk->events = DISK_EVENT_MEDIA_CHANGE;
         }
 }
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;
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index fd1e11799137..6e5123b1d341 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1781,7 +1781,7 @@ static int ide_cd_probe(ide_drive_t *drive)
 
         ide_cd_read_toc(drive, &sense);
         g->fops = &idecd_ops;
-        g->flags |= GENHD_FL_REMOVABLE;
+        g->flags |= GENHD_FL_REMOVABLE | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
         g->events = DISK_EVENT_MEDIA_CHANGE;
         add_disk(g);
         return 0;
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 95019c747cc1..4778e2707168 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -636,7 +636,7 @@ static int sr_probe(struct device *dev)
         disk->first_minor = minor;
         sprintf(disk->disk_name, "sr%d", minor);
         disk->fops = &sr_bdops;
-        disk->flags = GENHD_FL_CD;
+        disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
         disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 
         blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);