block: add a bdev_is_partition helper

Add a littler helper to make the somewhat arcane bd_contains checks a
little more obvious.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

4 files changed, 8 insertions, 8 deletions

diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c
index 09491098047b..58994da10c06 100644
--- a/drivers/ide/ide-ioctls.c
+++ b/drivers/ide/ide-ioctls.c
@@ -49,7 +49,7 @@ read_val:
 	return err >= 0 ? put_user_long(err, arg) : err;
 
 set_val:
-	if (bdev != bdev->bd_contains)
+	if (bdev_is_partition(bdev))
 		err = -EINVAL;
 	else {
 		if (!capable(CAP_SYS_ADMIN))
@@ -257,7 +257,7 @@ int generic_ide_ioctl(ide_drive_t *drive, struct block_device *bdev,
 	switch (cmd) {
 	case HDIO_OBSOLETE_IDENTITY:
 	case HDIO_GET_IDENTITY:
-		if (bdev != bdev->bd_contains)
+		if (bdev_is_partition(bdev))
 			return -EINVAL;
 		return ide_get_identity_ioctl(drive, cmd, argp);
 	case HDIO_GET_NICE:
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 405d7cf10eb9..12d909044c10 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -903,7 +903,7 @@ static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
 	struct request_queue *q = bdev_get_queue(bdev);
 
 	/* request-based cannot stack on partitions! */
-	if (bdev != bdev->bd_contains)
+	if (bdev_is_partition(bdev))
 		return false;
 
 	return queue_is_mq(q);
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index fa313b634135..8d3df0be0355 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -723,7 +723,7 @@ static int mmc_blk_check_blkdev(struct block_device *bdev)
 	 * whole block device, not on a partition.  This prevents overspray
 	 * between sibling partitions.
 	 */
-	if ((!capable(CAP_SYS_RAWIO)) || (bdev != bdev->bd_contains))
+	if (!capable(CAP_SYS_RAWIO) || bdev_is_partition(bdev))
 		return -EPERM;
 	return 0;
 }
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index faaf5596e31c..cb6427fb9f3d 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -277,7 +277,7 @@ dasd_ioctl_format(struct block_device *bdev, void __user *argp)
 		dasd_put_device(base);
 		return -EFAULT;
 	}
-	if (bdev != bdev->bd_contains) {
+	if (bdev_is_partition(bdev)) {
 		pr_warn("%s: The specified DASD is a partition and cannot be formatted\n",
 			dev_name(&base->cdev->dev));
 		dasd_put_device(base);
@@ -304,7 +304,7 @@ static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp)
 	base = dasd_device_from_gendisk(bdev->bd_disk);
 	if (!base)
 		return -ENODEV;
-	if (bdev != bdev->bd_contains) {
+	if (bdev_is_partition(bdev)) {
 		pr_warn("%s: The specified DASD is a partition and cannot be checked\n",
 			dev_name(&base->cdev->dev));
 		rc = -EINVAL;
@@ -362,7 +362,7 @@ static int dasd_ioctl_release_space(struct block_device *bdev, void __user *argp
 		rc = -EROFS;
 		goto out_err;
 	}
-	if (bdev != bdev->bd_contains) {
+	if (bdev_is_partition(bdev)) {
 		pr_warn("%s: The specified DASD is a partition and tracks cannot be released\n",
 			dev_name(&base->cdev->dev));
 		rc = -EINVAL;
@@ -540,7 +540,7 @@ dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
-	if (bdev != bdev->bd_contains)
+	if (bdev_is_partition(bdev))
 		// ro setting is not allowed for partitions
 		return -EINVAL;
 	if (get_user(intval, (int __user *)argp))