[PATCH] nvme/ioctl: allow 64-bit results in io-passthru command

[Tokunori Ikegami <ikegami.t@gmail.com>]

Deprecated NVME_IOCTL_IO_CMD ioctl on the char device.
But nvme-cli still uses it and NVME_IOCTL_IO64_CMD for now.
So add NVME_IOCTL_IO64_CMD also to allow it.
  Note: 32/62-bit ioctl duplicated code should be refactored.

Signed-off-by: Tokunori Ikegami <ikegami.t@gmail.com>
---
 drivers/nvme/host/ioctl.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 8844bbd39515..ff7df944ef53 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -845,6 +845,43 @@ static int nvme_dev_user_cmd(struct nvme_ctrl *ctrl, void __user *argp,
 	return ret;
 }
 
+static int nvme_dev_user_cmd64(struct nvme_ctrl *ctrl, void __user *argp,
+		bool open_for_write)
+{
+	struct nvme_ns *ns;
+	int ret, srcu_idx;
+
+	srcu_idx = srcu_read_lock(&ctrl->srcu);
+	if (list_empty(&ctrl->namespaces)) {
+		ret = -ENOTTY;
+		goto out_unlock;
+	}
+
+	ns = list_first_or_null_rcu(&ctrl->namespaces, struct nvme_ns, list);
+	if (ns != list_last_entry(&ctrl->namespaces, struct nvme_ns, list)) {
+		dev_warn(ctrl->device,
+			"NVME_IOCTL_IO64_CMD not supported when multiple namespaces present!\n");
+		ret = -EINVAL;
+		goto out_unlock;
+	}
+
+	dev_warn(ctrl->device,
+		"using deprecated NVME_IOCTL_IO64_CMD ioctl on the char device!\n");
+	if (!nvme_get_ns(ns)) {
+		ret = -ENXIO;
+		goto out_unlock;
+	}
+	srcu_read_unlock(&ctrl->srcu, srcu_idx);
+
+	ret = nvme_user_cmd64(ctrl, ns, argp, 0, open_for_write);
+	nvme_put_ns(ns);
+	return ret;
+
+out_unlock:
+	srcu_read_unlock(&ctrl->srcu, srcu_idx);
+	return ret;
+}
+
 long nvme_dev_ioctl(struct file *file, unsigned int cmd,
 		unsigned long arg)
 {
@@ -859,6 +896,8 @@ long nvme_dev_ioctl(struct file *file, unsigned int cmd,
 		return nvme_user_cmd64(ctrl, NULL, argp, 0, open_for_write);
 	case NVME_IOCTL_IO_CMD:
 		return nvme_dev_user_cmd(ctrl, argp, open_for_write);
+	case NVME_IOCTL_IO64_CMD:
+		return nvme_dev_user_cmd64(ctrl, argp, open_for_write);
 	case NVME_IOCTL_RESET:
 		if (!capable(CAP_SYS_ADMIN))
 			return -EACCES;
-- 
2.51.0