[PATCH v3 4/4] block: ublk_drv: Add a helper instead of casting

[Breno Leitao]

ublk driver is using casts to get private data from uring cmd struct.
Let's use a proper helper, as an interface that requires casts in all
callers is one asking for bugs.

Suggested-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
 drivers/block/ublk_drv.c | 36 ++++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index ec23a3c9fac8..1fa6a4d54d6d 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1261,9 +1261,21 @@ static void ublk_handle_need_get_data(struct ublk_device *ub, int q_id,
 	ublk_queue_cmd(ubq, req);
 }
 
+static inline struct ublksrv_ctrl_cmd *ublk_uring_ctrl_cmd(
+		struct io_uring_cmd *cmd)
+{
+	return (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+}
+
+static inline struct ublksrv_io_cmd *ublk_uring_io_cmd(
+		struct io_uring_cmd *cmd)
+{
+	return (struct ublksrv_io_cmd *)cmd->sqe->cmd;
+}
+
 static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
 {
-	struct ublksrv_io_cmd *ub_cmd = (struct ublksrv_io_cmd *)cmd->sqe->cmd;
+	struct ublksrv_io_cmd *ub_cmd = ublk_uring_io_cmd(cmd);
 	struct ublk_device *ub = cmd->file->private_data;
 	struct ublk_queue *ubq;
 	struct ublk_io *io;
@@ -1567,7 +1579,7 @@ static struct ublk_device *ublk_get_device_from_id(int idx)
 
 static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	int ublksrv_pid = (int)header->data[0];
 	struct gendisk *disk;
 	int ret = -EINVAL;
@@ -1630,7 +1642,7 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd)
 static int ublk_ctrl_get_queue_affinity(struct ublk_device *ub,
 		struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	void __user *argp = (void __user *)(unsigned long)header->addr;
 	cpumask_var_t cpumask;
 	unsigned long queue;
@@ -1681,7 +1693,7 @@ static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info)
 
 static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	void __user *argp = (void __user *)(unsigned long)header->addr;
 	struct ublksrv_ctrl_dev_info info;
 	struct ublk_device *ub;
@@ -1844,7 +1856,7 @@ static int ublk_ctrl_del_dev(struct ublk_device **p_ub)
 
 static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 
 	pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n",
 			__func__, cmd->cmd_op, header->dev_id, header->queue_id,
@@ -1863,7 +1875,7 @@ static int ublk_ctrl_stop_dev(struct ublk_device *ub)
 static int ublk_ctrl_get_dev_info(struct ublk_device *ub,
 		struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	void __user *argp = (void __user *)(unsigned long)header->addr;
 
 	if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr)
@@ -1894,7 +1906,7 @@ static void ublk_ctrl_fill_params_devt(struct ublk_device *ub)
 static int ublk_ctrl_get_params(struct ublk_device *ub,
 		struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	void __user *argp = (void __user *)(unsigned long)header->addr;
 	struct ublk_params_header ph;
 	int ret;
@@ -1925,7 +1937,7 @@ static int ublk_ctrl_get_params(struct ublk_device *ub,
 static int ublk_ctrl_set_params(struct ublk_device *ub,
 		struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	void __user *argp = (void __user *)(unsigned long)header->addr;
 	struct ublk_params_header ph;
 	int ret = -EFAULT;
@@ -1983,7 +1995,7 @@ static void ublk_queue_reinit(struct ublk_device *ub, struct ublk_queue *ubq)
 static int ublk_ctrl_start_recovery(struct ublk_device *ub,
 		struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	int ret = -EINVAL;
 	int i;
 
@@ -2025,7 +2037,7 @@ static int ublk_ctrl_start_recovery(struct ublk_device *ub,
 static int ublk_ctrl_end_recovery(struct ublk_device *ub,
 		struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	int ublksrv_pid = (int)header->data[0];
 	int ret = -EINVAL;
 
@@ -2092,7 +2104,7 @@ static int ublk_char_dev_permission(struct ublk_device *ub,
 static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub,
 		struct io_uring_cmd *cmd)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	bool unprivileged = ub->dev_info.flags & UBLK_F_UNPRIVILEGED_DEV;
 	void __user *argp = (void __user *)(unsigned long)header->addr;
 	char *dev_path = NULL;
@@ -2171,7 +2183,7 @@ static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub,
 static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
 		unsigned int issue_flags)
 {
-	struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->sqe->cmd;
+	struct ublksrv_ctrl_cmd *header = ublk_uring_ctrl_cmd(cmd);
 	struct ublk_device *ub = NULL;
 	int ret = -EINVAL;
 
-- 
2.34.1