Commit 0a9beafa authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

ublk: refactor auto buffer register in ublk_dispatch_req() 



Refactor auto buffer register code and prepare for supporting batch IO
feature, and the main motivation is to put 'ublk_io' operation code
together, so that per-io lock can be applied for the code block.

The key changes are:
- Rename ublk_auto_buf_reg() as ublk_do_auto_buf_reg()
- Introduce an enum `auto_buf_reg_res` to represent the result of
  the buffer registration attempt (FAIL, FALLBACK, OK).
- Split the existing `ublk_do_auto_buf_reg` function into two:
  - `__ublk_do_auto_buf_reg`: Performs the actual buffer registration
    and returns the `auto_buf_reg_res` status.
  - `ublk_do_auto_buf_reg`: A wrapper that calls the internal function
    and handles the I/O preparation based on the result.
- Introduce `ublk_prep_auto_buf_reg_io` to encapsulate the logic for
  preparing the I/O for completion after buffer registration.
- Pass the `tag` directly to `ublk_auto_buf_reg_fallback` to avoid
  recalculating it.

This refactoring makes the control flow clearer and isolates the different
stages of the auto buffer registration process.

Reviewed-by: default avatarCaleb Sander Mateos <csander@purestorage.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 8d61ece1

drivers/block/ublk_drv.c

+43 −21
Original line number Diff line number Diff line
@@ -1168,15 +1168,35 @@ static inline void __ublk_abort_rq(struct ublk_queue *ubq, 
}



static void

ublk_auto_buf_reg_fallback(const struct ublk_queue *ubq, struct ublk_io *io)

ublk_auto_buf_reg_fallback(const struct ublk_queue *ubq, unsigned tag)

{

	unsigned tag = io - ubq->ios;

	struct ublksrv_io_desc *iod = ublk_get_iod(ubq, tag);



	iod->op_flags |= UBLK_IO_F_NEED_REG_BUF;

}



static bool ublk_auto_buf_reg(const struct ublk_queue *ubq, struct request *req,

enum auto_buf_reg_res {

	AUTO_BUF_REG_FAIL,

	AUTO_BUF_REG_FALLBACK,

	AUTO_BUF_REG_OK,

};



static void ublk_prep_auto_buf_reg_io(const struct ublk_queue *ubq,

				      struct request *req, struct ublk_io *io,

				      struct io_uring_cmd *cmd,

				      enum auto_buf_reg_res res)

{

	if (res == AUTO_BUF_REG_OK) {

		io->task_registered_buffers = 1;

		io->buf_ctx_handle = io_uring_cmd_ctx_handle(cmd);

		io->flags |= UBLK_IO_FLAG_AUTO_BUF_REG;

	}

	ublk_init_req_ref(ubq, io);

	__ublk_prep_compl_io_cmd(io, req);

}



static enum auto_buf_reg_res

__ublk_do_auto_buf_reg(const struct ublk_queue *ubq, struct request *req,

		       struct ublk_io *io, struct io_uring_cmd *cmd,

		       unsigned int issue_flags)

{
@@ -1186,29 +1206,27 @@ static bool ublk_auto_buf_reg(const struct ublk_queue *ubq, struct request *req, 
				      io->buf.auto_reg.index, issue_flags);

	if (ret) {

		if (io->buf.auto_reg.flags & UBLK_AUTO_BUF_REG_FALLBACK) {

			ublk_auto_buf_reg_fallback(ubq, io);

			return true;

			ublk_auto_buf_reg_fallback(ubq, req->tag);

			return AUTO_BUF_REG_FALLBACK;

		}

		blk_mq_end_request(req, BLK_STS_IOERR);

		return false;

		return AUTO_BUF_REG_FAIL;

	}



	io->task_registered_buffers = 1;

	io->buf_ctx_handle = io_uring_cmd_ctx_handle(cmd);

	io->flags |= UBLK_IO_FLAG_AUTO_BUF_REG;

	return true;

	return AUTO_BUF_REG_OK;

}



static bool ublk_prep_auto_buf_reg(struct ublk_queue *ubq,

				   struct request *req, struct ublk_io *io,

				   struct io_uring_cmd *cmd,

static void ublk_do_auto_buf_reg(const struct ublk_queue *ubq, struct request *req,

				 struct ublk_io *io, struct io_uring_cmd *cmd,

				 unsigned int issue_flags)

{

	ublk_init_req_ref(ubq, io);

	if (ublk_support_auto_buf_reg(ubq) && ublk_rq_has_data(req))

		return ublk_auto_buf_reg(ubq, req, io, cmd, issue_flags);

	enum auto_buf_reg_res res = __ublk_do_auto_buf_reg(ubq, req, io, cmd,

			issue_flags);



	return true;

	if (res != AUTO_BUF_REG_FAIL) {

		ublk_prep_auto_buf_reg_io(ubq, req, io, cmd, res);

		io_uring_cmd_done(cmd, UBLK_IO_RES_OK, issue_flags);

	}

}



static bool ublk_start_io(const struct ublk_queue *ubq, struct request *req,
@@ -1281,9 +1299,13 @@ static void ublk_dispatch_req(struct ublk_queue *ubq, 
	if (!ublk_start_io(ubq, req, io))

		return;



	if (ublk_prep_auto_buf_reg(ubq, req, io, io->cmd, issue_flags))

	if (ublk_support_auto_buf_reg(ubq) && ublk_rq_has_data(req)) {

		ublk_do_auto_buf_reg(ubq, req, io, io->cmd, issue_flags);

	} else {

		ublk_init_req_ref(ubq, io);

		ublk_complete_io_cmd(io, req, UBLK_IO_RES_OK, issue_flags);

	}

}



static void ublk_cmd_tw_cb(struct io_uring_cmd *cmd,

			   unsigned int issue_flags)