io_uring: kill ref get/drop in personality init
authorPavel Begunkov <asml.silence@gmail.com>
Sun, 18 Oct 2020 09:17:38 +0000 (10:17 +0100)
committerJens Axboe <axboe@kernel.dk>
Mon, 19 Oct 2020 19:29:29 +0000 (13:29 -0600)
Don't take an identity on personality/creds init only to drop it a few
lines after. Extract a function which prepares req->work but leaves it
without identity.

Note: it's safe to not check REQ_F_WORK_INITIALIZED there because it's
nobody had a chance to init it before io_init_req().

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

index e9e8006..b96ef25 100644 (file)
@@ -1070,6 +1070,12 @@ static void io_init_identity(struct io_identity *id)
        refcount_set(&id->count, 1);
 }
 
+static inline void __io_req_init_async(struct io_kiocb *req)
+{
+       memset(&req->work, 0, sizeof(req->work));
+       req->flags |= REQ_F_WORK_INITIALIZED;
+}
+
 /*
  * Note: must call io_req_init_async() for the first time you
  * touch any members of io_wq_work.
@@ -1081,8 +1087,7 @@ static inline void io_req_init_async(struct io_kiocb *req)
        if (req->flags & REQ_F_WORK_INITIALIZED)
                return;
 
-       memset(&req->work, 0, sizeof(req->work));
-       req->flags |= REQ_F_WORK_INITIALIZED;
+       __io_req_init_async(req);
 
        /* Grab a ref if this isn't our static identity */
        req->work.identity = tctx->identity;
@@ -6504,12 +6509,12 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
        if (id) {
                struct io_identity *iod;
 
-               io_req_init_async(req);
                iod = idr_find(&ctx->personality_idr, id);
                if (unlikely(!iod))
                        return -EINVAL;
                refcount_inc(&iod->count);
-               io_put_identity(current->io_uring, req);
+
+               __io_req_init_async(req);
                get_cred(iod->creds);
                req->work.identity = iod;
                req->work.flags |= IO_WQ_WORK_CREDS;