Commit 21bb9fac authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

ublk: store auto buffer register data into `struct ublk_io` 



We can share space of `io->addr` for storing auto buffer register data
and user space buffer address.

So store auto buffer register data into `struct ublk_io`.

Prepare for supporting batch IO in which many ublk IOs share single
uring_cmd, so we can't store auto buffer register data into uring_cmd
pdu.

Reviewed-by: default avatarCaleb Sander Mateos <csander@purestorage.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250713143415.2857561-8-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 52460dda

drivers/block/ublk_drv.c

+12 −18
Original line number Diff line number Diff line
@@ -105,8 +105,6 @@ struct ublk_uring_cmd_pdu { 
	 */

	struct ublk_queue *ubq;



	struct ublk_auto_buf_reg buf;



	u16 tag;

};
@@ -159,7 +157,10 @@ struct ublk_uring_cmd_pdu { 


struct ublk_io {

	/* userspace buffer address from io cmd */

	union {

		__u64	addr;

		struct ublk_auto_buf_reg buf;

	};

	unsigned int flags;

	int res;
@@ -187,8 +188,6 @@ struct ublk_io { 
	/* Count of buffers registered on task and not yet unregistered */

	unsigned task_registered_buffers;



	/* auto-registered buffer, valid if UBLK_IO_FLAG_AUTO_BUF_REG is set */

	u16 buf_index;

	void *buf_ctx_handle;

} ____cacheline_aligned_in_smp;
@@ -1217,13 +1216,12 @@ ublk_auto_buf_reg_fallback(const struct ublk_queue *ubq, struct ublk_io *io) 
static bool ublk_auto_buf_reg(const struct ublk_queue *ubq, struct request *req,

			      struct ublk_io *io, unsigned int issue_flags)

{

	struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(io->cmd);

	int ret;



	ret = io_buffer_register_bvec(io->cmd, req, ublk_io_release,

				      pdu->buf.index, issue_flags);

				      io->buf.index, issue_flags);

	if (ret) {

		if (pdu->buf.flags & UBLK_AUTO_BUF_REG_FALLBACK) {

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

			ublk_auto_buf_reg_fallback(ubq, io);

			return true;

		}
@@ -1233,8 +1231,6 @@ static bool ublk_auto_buf_reg(const struct ublk_queue *ubq, struct request *req, 


	io->task_registered_buffers = 1;

	io->buf_ctx_handle = io_uring_cmd_ctx_handle(io->cmd);

	/* store buffer index in request payload */

	io->buf_index = pdu->buf.index;

	io->flags |= UBLK_IO_FLAG_AUTO_BUF_REG;

	return true;

}
@@ -2011,16 +2007,14 @@ static inline int ublk_check_cmd_op(u32 cmd_op) 
	return 0;

}



static inline int ublk_set_auto_buf_reg(struct io_uring_cmd *cmd)

static inline int ublk_set_auto_buf_reg(struct ublk_io *io, struct io_uring_cmd *cmd)

{

	struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);



	pdu->buf = ublk_sqe_addr_to_auto_buf_reg(READ_ONCE(cmd->sqe->addr));

	io->buf = ublk_sqe_addr_to_auto_buf_reg(READ_ONCE(cmd->sqe->addr));



	if (pdu->buf.reserved0 || pdu->buf.reserved1)

	if (io->buf.reserved0 || io->buf.reserved1)

		return -EINVAL;



	if (pdu->buf.flags & ~UBLK_AUTO_BUF_REG_F_MASK)

	if (io->buf.flags & ~UBLK_AUTO_BUF_REG_F_MASK)

		return -EINVAL;

	return 0;

}
@@ -2043,10 +2037,10 @@ static int ublk_handle_auto_buf_reg(struct ublk_io *io, 
		 * this ublk request gets stuck.

		 */

		if (io->buf_ctx_handle == io_uring_cmd_ctx_handle(cmd))

			*buf_idx = io->buf_index;

			*buf_idx = io->buf.index;

	}



	return ublk_set_auto_buf_reg(cmd);

	return ublk_set_auto_buf_reg(io, cmd);

}



/* Once we return, `io->req` can't be used any more */