[PATCH] io_uring/uring_cmd: skip inline completion cleanup if unlocked

[Jens Axboe <axboe@kernel.dk>]

If the call path to __io_uring_cmd_done() is not locked, then we
cannot recycle the uring_cmd to our allocation cache. Check for
that and skip it, and let the normal locked completion flushing
do the cleanup.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

---

This effectively defeats proper cache recyling for uring_cmd opcodes,
with the fix it's working fine again.

diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 42be1be5b132..35e2aa8b9446 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -166,7 +166,9 @@ void __io_uring_cmd_done(struct io_uring_cmd *ioucmd, s32 ret, u64 res2,
 			req->cqe.flags |= IORING_CQE_F_32;
 		io_req_set_cqe32_extra(req, res2, 0);
 	}
-	io_req_uring_cleanup(req, issue_flags);
+	/* defer cleanup if not locked, otherwise cache recyling is skipped */
+	if (!(issue_flags & IO_URING_F_UNLOCKED))
+		io_req_uring_cleanup(req, issue_flags);
 	if (req->flags & REQ_F_IOPOLL) {
 		/* order with io_iopoll_req_issued() checking ->iopoll_complete */
 		smp_store_release(&req->iopoll_completed, 1);
@@ -211,6 +213,7 @@ int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	ac = io_uring_alloc_async_data(&req->ctx->cmd_cache, req);
 	if (!ac)
 		return -ENOMEM;
+	req->flags |= REQ_F_NEED_CLEANUP;
 	ioucmd->sqe = sqe;
 	return 0;
 }

-- 
Jens Axboe