Commit d4dc210f authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

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: default avatarTejun Heo <tj@kernel.org>
Reported-by: default avatarKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent 1196f8b8

drivers/block/paride/pcd.c

+1 −0
Original line number Diff line number Diff line
@@ -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;

	}

}

drivers/cdrom/viocd.c

+2 −1
Original line number Diff line number Diff line
@@ -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;

drivers/ide/ide-cd.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

drivers/scsi/sr.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

fs/block_dev.c

+10 −7
Original line number Diff line number Diff line
@@ -1237,6 +1237,8 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) 
	res = __blkdev_get(bdev, mode, 0);



	if (whole) {

		struct gendisk *disk = whole->bd_disk;



		/* finish claiming */

		mutex_lock(&bdev->bd_mutex);

		spin_lock(&bdev_lock);
@@ -1263,15 +1265,16 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) 
		spin_unlock(&bdev_lock);



		/*

		 * Block event polling for write claims.  Any write

		 * holder makes the write_holder state stick until all

		 * are released.  This is good enough and tracking

		 * individual writeable reference is too fragile given

		 * the way @mode is used in blkdev_get/put().

		 * Block event polling for write claims if requested.  Any

		 * write holder makes the write_holder state stick until

		 * all are released.  This is good enough and tracking

		 * individual writeable reference is too fragile given the

		 * way @mode is used in blkdev_get/put().

		 */

		if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {

		if ((disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE) &&

		    !res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {

			bdev->bd_write_holder = true;

			disk_block_events(bdev->bd_disk);

			disk_block_events(disk);

		}



		mutex_unlock(&bdev->bd_mutex);

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