[PATCH v2 05/20] dm: Add support for block PR read keys/reservation.

[Mike Christie]

This adds support in dm for the block PR read keys and read reservation
callouts.

Signed-off-by: Mike Christie <michael.christie at oracle.com>
---
 drivers/md/dm.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 60549b65c799..1b15295bdf24 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -3313,12 +3313,56 @@ static int dm_pr_clear(struct block_device *bdev, u64 key)
 	return r;
 }
 
+static int dm_pr_read_keys(struct block_device *bdev, struct pr_keys *keys,
+			   u32 keys_len)
+{
+	struct mapped_device *md = bdev->bd_disk->private_data;
+	const struct pr_ops *ops;
+	int r, srcu_idx;
+
+	r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
+	if (r < 0)
+		goto out;
+
+	ops = bdev->bd_disk->fops->pr_ops;
+	if (ops && ops->pr_read_keys)
+		r = ops->pr_read_keys(bdev, keys, keys_len);
+	else
+		r = -EOPNOTSUPP;
+out:
+	dm_unprepare_ioctl(md, srcu_idx);
+	return r;
+}
+
+static int dm_pr_read_reservation(struct block_device *bdev,
+				  struct pr_held_reservation *rsv)
+{
+	struct mapped_device *md = bdev->bd_disk->private_data;
+	const struct pr_ops *ops;
+	int r, srcu_idx;
+
+	r = dm_prepare_ioctl(md, &srcu_idx, &bdev);
+	if (r < 0)
+		goto out;
+
+	ops = bdev->bd_disk->fops->pr_ops;
+	if (ops && ops->pr_read_reservation)
+		r = ops->pr_read_reservation(bdev, rsv);
+	else
+		r = -EOPNOTSUPP;
+out:
+	dm_unprepare_ioctl(md, srcu_idx);
+	return r;
+}
+
 static const struct pr_ops dm_pr_ops = {
 	.pr_register	= dm_pr_register,
 	.pr_reserve	= dm_pr_reserve,
 	.pr_release	= dm_pr_release,
 	.pr_preempt	= dm_pr_preempt,
 	.pr_clear	= dm_pr_clear,
+	.pr_read_keys	= dm_pr_read_keys,
+	.pr_read_reservation = dm_pr_read_reservation,
 };
 
 static const struct block_device_operations dm_blk_dops = {
-- 
2.18.2