[PATCH 1/4] io_uring/uring_cmd: get rid of using req->imu

[Jens Axboe <axboe@xxxxxxxxx>]

It's pretty pointless to use io_kiocb as intermediate storage for this,
so split the validity check and the actual usage.

Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
 io_uring/uring_cmd.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 39c3c816ec78..cc8bb5550ff5 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -211,11 +211,10 @@ int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 		struct io_ring_ctx *ctx = req->ctx;
 		u16 index;
 
-		req->buf_index = READ_ONCE(sqe->buf_index);
+		index = READ_ONCE(sqe->buf_index);
+		req->buf_index = array_index_nospec(index, ctx->nr_user_bufs);
 		if (unlikely(req->buf_index >= ctx->nr_user_bufs))
 			return -EFAULT;
-		index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
-		req->imu = ctx->user_bufs[index];
 		io_req_set_rsrc_node(req, ctx, 0);
 	}
 	ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
@@ -272,8 +271,10 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 			      struct iov_iter *iter, void *ioucmd)
 {
 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
+	struct io_mapped_ubuf *imu;
 
-	return io_import_fixed(rw, iter, req->imu, ubuf, len);
+	imu = req->ctx->user_bufs[req->buf_index];
+	return io_import_fixed(rw, iter, imu, ubuf, len);
 }
 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
 
-- 
2.45.2