io_uring: refactor io_flush_cached_reqs()
authorPavel Begunkov <asml.silence@gmail.com>
Fri, 19 Mar 2021 17:22:35 +0000 (17:22 +0000)
committerJens Axboe <axboe@kernel.dk>
Sun, 11 Apr 2021 23:41:58 +0000 (17:41 -0600)
Emphasize that return value of io_flush_cached_reqs() depends on number
of requests in the cache. It looks nicer and might help tools from
false-negative analyses.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/io_uring.c

index b08813e..7623188 100644 (file)
@@ -1627,11 +1627,12 @@ static void io_req_complete_failed(struct io_kiocb *req, long res)
        io_req_complete_post(req, res, 0);
 }
 
+/* Returns true IFF there are requests in the cache */
 static bool io_flush_cached_reqs(struct io_ring_ctx *ctx)
 {
        struct io_submit_state *state = &ctx->submit_state;
        struct io_comp_state *cs = &state->comp;
-       struct io_kiocb *req = NULL;
+       int nr;
 
        /*
         * If we have more than a batch's worth of requests in our IRQ side
@@ -1645,16 +1646,19 @@ static bool io_flush_cached_reqs(struct io_ring_ctx *ctx)
                spin_unlock_irq(&ctx->completion_lock);
        }
 
+       nr = state->free_reqs;
        while (!list_empty(&cs->free_list)) {
-               req = list_first_entry(&cs->free_list, struct io_kiocb,
-                                       compl.list);
+               struct io_kiocb *req = list_first_entry(&cs->free_list,
+                                               struct io_kiocb, compl.list);
+
                list_del(&req->compl.list);
-               state->reqs[state->free_reqs++] = req;
-               if (state->free_reqs == ARRAY_SIZE(state->reqs))
+               state->reqs[nr++] = req;
+               if (nr == ARRAY_SIZE(state->reqs))
                        break;
        }
 
-       return req != NULL;
+       state->free_reqs = nr;
+       return nr != 0;
 }
 
 static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)