io_uring: use regular request ref counts
Get rid of the special casing of "normal" requests not having
any references to the io_kiocb. We initialize the ref count to 2,
one for the submission side, and one or the completion side.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 5d99376..9071fca 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -411,7 +411,8 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx,
req->ctx = ctx;
req->flags = 0;
- refcount_set(&req->refs, 0);
+ /* one is dropped after submission, the other at completion */
+ refcount_set(&req->refs, 2);
return req;
out:
io_ring_drop_ctx_refs(ctx, 1);
@@ -429,10 +430,14 @@ static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr)
static void io_free_req(struct io_kiocb *req)
{
- if (!refcount_read(&req->refs) || refcount_dec_and_test(&req->refs)) {
- io_ring_drop_ctx_refs(req->ctx, 1);
- kmem_cache_free(req_cachep, req);
- }
+ io_ring_drop_ctx_refs(req->ctx, 1);
+ kmem_cache_free(req_cachep, req);
+}
+
+static void io_put_req(struct io_kiocb *req)
+{
+ if (refcount_dec_and_test(&req->refs))
+ io_free_req(req);
}
/*
@@ -453,7 +458,8 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
io_cqring_fill_event(ctx, req->user_data, req->error, 0);
- reqs[to_free++] = req;
+ if (refcount_dec_and_test(&req->refs))
+ reqs[to_free++] = req;
(*nr_events)++;
/*
@@ -616,7 +622,7 @@ static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
io_fput(req);
io_cqring_add_event(req->ctx, req->user_data, res, 0);
- io_free_req(req);
+ io_put_req(req);
}
static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
@@ -1083,7 +1089,7 @@ static int io_nop(struct io_kiocb *req, u64 user_data)
io_fput(req);
}
io_cqring_add_event(ctx, user_data, err, 0);
- io_free_req(req);
+ io_put_req(req);
return 0;
}
@@ -1146,7 +1152,7 @@ static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe,
io_fput(req);
io_cqring_add_event(req->ctx, sqe->user_data, ret, 0);
- io_free_req(req);
+ io_put_req(req);
return 0;
}
@@ -1204,7 +1210,7 @@ static int io_poll_remove(struct io_kiocb *req, const struct io_uring_sqe *sqe)
spin_unlock_irq(&ctx->completion_lock);
io_cqring_add_event(req->ctx, sqe->user_data, ret, 0);
- io_free_req(req);
+ io_put_req(req);
return 0;
}
@@ -1212,7 +1218,7 @@ static void io_poll_complete(struct io_kiocb *req, __poll_t mask)
{
io_cqring_add_event(req->ctx, req->user_data, mangle_poll(mask), 0);
io_fput(req);
- io_free_req(req);
+ io_put_req(req);
}
static void io_poll_complete_work(struct work_struct *work)
@@ -1346,9 +1352,6 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe)
INIT_LIST_HEAD(&poll->wait.entry);
init_waitqueue_func_entry(&poll->wait, io_poll_wake);
- /* one for removal from waitqueue, one for this function */
- refcount_set(&req->refs, 2);
-
mask = vfs_poll(poll->file, &ipt.pt) & poll->events;
if (unlikely(!poll->head)) {
/* we did not manage to set up a waitqueue, done */
@@ -1380,13 +1383,12 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe)
* Drop one of our refs to this req, __io_submit_sqe() will
* drop the other one since we're returning an error.
*/
- io_free_req(req);
+ io_put_req(req);
return ipt.error;
}
if (mask)
io_poll_complete(req, mask);
- io_free_req(req);
return 0;
}
@@ -1524,10 +1526,13 @@ static void io_sq_wq_submit_work(struct work_struct *work)
break;
cond_resched();
} while (1);
+
+ /* drop submission reference */
+ io_put_req(req);
}
if (ret) {
io_cqring_add_event(ctx, sqe->user_data, ret, 0);
- io_free_req(req);
+ io_put_req(req);
}
/* async context always use a copy of the sqe */
@@ -1649,11 +1654,22 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s,
INIT_WORK(&req->work, io_sq_wq_submit_work);
queue_work(ctx->sqo_wq, &req->work);
}
- ret = 0;
+
+ /*
+ * Queued up for async execution, worker will release
+ * submit reference when the iocb is actually
+ * submitted.
+ */
+ return 0;
}
}
+
+ /* drop submission reference */
+ io_put_req(req);
+
+ /* and drop final reference, if we failed */
if (ret)
- io_free_req(req);
+ io_put_req(req);
return ret;
}
