Commit 3446583f authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

ublk: add helper ublk_check_fetch_buf() 



Add a helper ublk_check_fetch_buf() to validate UBLK_IO_FETCH_REQ's addr.
This doesn't require access to the ublk_io, so it can be done before taking
the ublk_device mutex.

This way also fixes one missing return value of -EINVAL in case of early
failure from ublk_fetch().

Fixes: b69b8edf ("ublk: properly serialize all FETCH_REQs")
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/20250713143415.2857561-9-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 21bb9fac

drivers/block/ublk_drv.c

+19 −13
Original line number Diff line number Diff line
@@ -2165,6 +2165,22 @@ static int ublk_unregister_io_buf(struct io_uring_cmd *cmd, 
	return io_buffer_unregister_bvec(cmd, index, issue_flags);

}



static int ublk_check_fetch_buf(const struct ublk_queue *ubq, __u64 buf_addr)

{

	if (ublk_need_map_io(ubq)) {

		/*

		 * FETCH_RQ has to provide IO buffer if NEED GET

		 * DATA is not enabled

		 */

		if (!buf_addr && !ublk_need_get_data(ubq))

			return -EINVAL;

	} else if (buf_addr) {

		/* User copy requires addr to be unset */

		return -EINVAL;

	}

	return 0;

}



static int ublk_fetch(struct io_uring_cmd *cmd, struct ublk_queue *ubq,

		      struct ublk_io *io, __u64 buf_addr)

{
@@ -2191,19 +2207,6 @@ static int ublk_fetch(struct io_uring_cmd *cmd, struct ublk_queue *ubq, 


	WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV);



	if (ublk_need_map_io(ubq)) {

		/*

		 * FETCH_RQ has to provide IO buffer if NEED GET

		 * DATA is not enabled

		 */

		if (!buf_addr && !ublk_need_get_data(ubq))

			goto out;

	} else if (buf_addr) {

		/* User copy requires addr to be unset */

		ret = -EINVAL;

		goto out;

	}



	ublk_fill_io_cmd(io, cmd);

	ret = ublk_config_io_buf(ubq, io, cmd, buf_addr, NULL);

	if (ret)
@@ -2316,6 +2319,9 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd, 
	io = &ubq->ios[tag];

	/* UBLK_IO_FETCH_REQ can be handled on any task, which sets io->task */

	if (unlikely(_IOC_NR(cmd_op) == UBLK_IO_FETCH_REQ)) {

		ret = ublk_check_fetch_buf(ubq, ub_cmd->addr);

		if (ret)

			goto out;

		ret = ublk_fetch(cmd, ubq, io, ub_cmd->addr);

		if (ret)

			goto out;