[RFC PATCH 1/7] io_uring: add 'struct io_buf_data' for register/unregister bvec buffer

[Ming Lei <ming.lei@redhat.com>]

Add 'struct io_buf_data' for register/unregister bvec buffer, and
prepare for supporting to register buffer into one specified io_uring
context by its FD.

No functional change.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c     | 13 ++++++++++---
 include/linux/io_uring/cmd.h | 11 ++++++++---
 io_uring/rsrc.c              | 12 ++++++++----
 3 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 0d82014679f8..ac56482b55f5 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1925,6 +1925,10 @@ static int ublk_register_io_buf(struct io_uring_cmd *cmd,
 {
 	struct ublk_device *ub = cmd->file->private_data;
 	const struct ublk_io *io = &ubq->ios[tag];
+	struct io_buf_data data = {
+		.index = index,
+		.release = ublk_io_release,
+	};
 	struct request *req;
 	int ret;
 
@@ -1938,8 +1942,8 @@ static int ublk_register_io_buf(struct io_uring_cmd *cmd,
 	if (!req)
 		return -EINVAL;
 
-	ret = io_buffer_register_bvec(cmd, req, ublk_io_release, index,
-				      issue_flags);
+	data.rq = req;
+	ret = io_buffer_register_bvec(cmd, &data, issue_flags);
 	if (ret) {
 		ublk_put_req_ref(ubq, req);
 		return ret;
@@ -1953,6 +1957,9 @@ static int ublk_unregister_io_buf(struct io_uring_cmd *cmd,
 				  unsigned int index, unsigned int issue_flags)
 {
 	const struct ublk_io *io = &ubq->ios[tag];
+	struct io_buf_data data = {
+		.index = index,
+	};
 
 	if (!ublk_support_zero_copy(ubq))
 		return -EINVAL;
@@ -1960,7 +1967,7 @@ static int ublk_unregister_io_buf(struct io_uring_cmd *cmd,
 	if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV))
 		return -EINVAL;
 
-	return io_buffer_unregister_bvec(cmd, index, issue_flags);
+	return io_buffer_unregister_bvec(cmd, &data, issue_flags);
 }
 
 static int ublk_fetch(struct io_uring_cmd *cmd, struct ublk_queue *ubq,
diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
index 0634a3de1782..78fa336a284b 100644
--- a/include/linux/io_uring/cmd.h
+++ b/include/linux/io_uring/cmd.h
@@ -23,6 +23,12 @@ struct io_uring_cmd_data {
 	void			*op_data;
 };
 
+struct io_buf_data {
+	unsigned short index;
+	struct request *rq;
+	void (*release)(void *);
+};
+
 static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe)
 {
 	return sqe->cmd;
@@ -140,10 +146,9 @@ static inline struct io_uring_cmd_data *io_uring_cmd_get_async_data(struct io_ur
 	return cmd_to_io_kiocb(cmd)->async_data;
 }
 
-int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq,
-			    void (*release)(void *), unsigned int index,
+int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct io_buf_data *data,
 			    unsigned int issue_flags);
-int io_buffer_unregister_bvec(struct io_uring_cmd *cmd, unsigned int index,
+int io_buffer_unregister_bvec(struct io_uring_cmd *cmd, struct io_buf_data *data,
 			      unsigned int issue_flags);
 
 #endif /* _LINUX_IO_URING_CMD_H */
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index b4c5f3ee8855..66d2c11e2f46 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -918,12 +918,14 @@ int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
 	return ret;
 }
 
-int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq,
-			    void (*release)(void *), unsigned int index,
+int io_buffer_register_bvec(struct io_uring_cmd *cmd,
+			    struct io_buf_data *buf,
 			    unsigned int issue_flags)
 {
 	struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx;
 	struct io_rsrc_data *data = &ctx->buf_table;
+	unsigned int index = buf->index;
+	struct request *rq = buf->rq;
 	struct req_iterator rq_iter;
 	struct io_mapped_ubuf *imu;
 	struct io_rsrc_node *node;
@@ -963,7 +965,7 @@ int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq,
 	imu->folio_shift = PAGE_SHIFT;
 	imu->nr_bvecs = nr_bvecs;
 	refcount_set(&imu->refs, 1);
-	imu->release = release;
+	imu->release = buf->release;
 	imu->priv = rq;
 	imu->is_kbuf = true;
 	imu->dir = 1 << rq_data_dir(rq);
@@ -980,11 +982,13 @@ int io_buffer_register_bvec(struct io_uring_cmd *cmd, struct request *rq,
 }
 EXPORT_SYMBOL_GPL(io_buffer_register_bvec);
 
-int io_buffer_unregister_bvec(struct io_uring_cmd *cmd, unsigned int index,
+int io_buffer_unregister_bvec(struct io_uring_cmd *cmd,
+			      struct io_buf_data *buf,
 			      unsigned int issue_flags)
 {
 	struct io_ring_ctx *ctx = cmd_to_io_kiocb(cmd)->ctx;
 	struct io_rsrc_data *data = &ctx->buf_table;
+	unsigned index = buf->index;
 	struct io_rsrc_node *node;
 	int ret = 0;
 
-- 
2.47.0