From fd9b8547bc5c34186dc42ea05fb4380d21695374 Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Thu, 4 May 2023 05:18:55 -0700 Subject: io_uring: Pass whole sqe to commands Currently uring CMD operation relies on having large SQEs, but future operations might want to use normal SQE. The io_uring_cmd currently only saves the payload (cmd) part of the SQE, but, for commands that use normal SQE size, it might be necessary to access the initial SQE fields outside of the payload/cmd block. So, saves the whole SQE other than just the pdu. This changes slightly how the io_uring_cmd works, since the cmd structures and callbacks are not opaque to io_uring anymore. I.e, the callbacks can look at the SQE entries, not only, in the cmd structure. The main advantage is that we don't need to create custom structures for simple commands. Creates io_uring_sqe_cmd() that returns the cmd private data as a null pointer and avoids casting in the callee side. Also, make most of ublk_drv's sqe->cmd priv structure into const, and use io_uring_sqe_cmd() to get the private structure, removing the unwanted cast. (There is one case where the cast is still needed since the header->{len,addr} is updated in the private structure) Suggested-by: Pavel Begunkov Signed-off-by: Breno Leitao Reviewed-by: Keith Busch Reviewed-by: Christoph Hellwig Reviewed-by: Pavel Begunkov Link: https://lore.kernel.org/r/20230504121856.904491-3-leitao@debian.org Signed-off-by: Jens Axboe --- io_uring/uring_cmd.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'io_uring/uring_cmd.c') diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index 5113c9a48583..ed536d7499db 100644 --- a/io_uring/uring_cmd.c +++ b/io_uring/uring_cmd.c @@ -69,15 +69,12 @@ EXPORT_SYMBOL_GPL(io_uring_cmd_done); int io_uring_cmd_prep_async(struct io_kiocb *req) { struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd); - size_t cmd_size; BUILD_BUG_ON(uring_cmd_pdu_size(0) != 16); BUILD_BUG_ON(uring_cmd_pdu_size(1) != 80); - cmd_size = uring_cmd_pdu_size(req->ctx->flags & IORING_SETUP_SQE128); - - memcpy(req->async_data, ioucmd->cmd, cmd_size); - ioucmd->cmd = req->async_data; + memcpy(req->async_data, ioucmd->sqe, uring_sqe_size(req->ctx)); + ioucmd->sqe = req->async_data; return 0; } @@ -103,7 +100,7 @@ int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) req->imu = ctx->user_bufs[index]; io_req_set_rsrc_node(req, ctx, 0); } - ioucmd->cmd = sqe->cmd; + ioucmd->sqe = sqe; ioucmd->cmd_op = READ_ONCE(sqe->cmd_op); return 0; } -- cgit v1.2.3