io_uring: io_import_iovec return type cleanup

io_import_iovec() doesn't return IO size anymore, only error code. Make
it more apparent by returning int instead of ssize and clean up
leftovers.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -1030,9 +1030,8 @@ static struct file *io_file_get(struct io_submit_state *state,
 static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs);
 static void io_rsrc_put_work(struct work_struct *work);
 
-static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
-			       struct iovec **iovec, struct iov_iter *iter,
-			       bool needs_lock);
+static int io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec,
+			   struct iov_iter *iter, bool needs_lock);
 static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
 			     const struct iovec *fast_iov,
 			     struct iov_iter *iter, bool force);
@@ -2693,9 +2692,8 @@ static void io_complete_rw_common(struct kiocb *kiocb, long res,
 static bool io_resubmit_prep(struct io_kiocb *req)
 {
 	struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
-	ssize_t ret = -ECANCELED;
+	int rw, ret = -ECANCELED;
 	struct iov_iter iter;
-	int rw;
 
 	/* already prepared */
 	if (req->async_data)
@@ -3004,8 +3002,7 @@ static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
 		io_rw_done(kiocb, ret);
 }
 
-static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
-			       struct iov_iter *iter)
+static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter)
 {
 	struct io_ring_ctx *ctx = req->ctx;
 	size_t len = req->rw.len;
@@ -3069,7 +3066,7 @@ static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
 		}
 	}
 
-	return len;
+	return 0;
 }
 
 static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
@@ -3210,16 +3207,14 @@ static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
 	return __io_iov_buffer_select(req, iov, needs_lock);
 }
 
-static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
-				 struct iovec **iovec, struct iov_iter *iter,
-				 bool needs_lock)
+static int io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec,
+			   struct iov_iter *iter, bool needs_lock)
 {
 	void __user *buf = u64_to_user_ptr(req->rw.addr);
 	size_t sqe_len = req->rw.len;
+	u8 opcode = req->opcode;
 	ssize_t ret;
-	u8 opcode;
 
-	opcode = req->opcode;
 	if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
 		*iovec = NULL;
 		return io_import_fixed(req, rw, iter);
@@ -3244,10 +3239,8 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
 
 	if (req->flags & REQ_F_BUFFER_SELECT) {
 		ret = io_iov_buffer_select(req, *iovec, needs_lock);
-		if (!ret) {
-			ret = (*iovec)->iov_len;
-			iov_iter_init(iter, rw, *iovec, 1, ret);
-		}
+		if (!ret)
+			iov_iter_init(iter, rw, *iovec, 1, (*iovec)->iov_len);
 		*iovec = NULL;
 		return ret;
 	}
@@ -3379,7 +3372,7 @@ static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
 {
 	struct io_async_rw *iorw = req->async_data;
 	struct iovec *iov = iorw->fast_iov;
-	ssize_t ret;
+	int ret;
 
 	ret = io_import_iovec(rw, req, &iov, &iorw->iter, false);
 	if (unlikely(ret < 0))
@@ -3518,7 +3511,6 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
 	}
 	io_size = iov_iter_count(iter);
 	req->result = io_size;
-	ret = 0;
 
 	/* Ensure we clear previously set non-block flag */
 	if (!force_nonblock)