[PATCH v2 3/4] io_uring/rw: extract helper for iovec import

[Pavel Begunkov <asml.silence@gmail.com>]

Split out a helper out of __io_import_rw_buffer() that handles vectored
buffers. I'll need it for registered vectored buffers, but it also looks
cleaner, especially with parameters being properly named.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/rw.c | 57 ++++++++++++++++++++++++++++-----------------------
 1 file changed, 31 insertions(+), 26 deletions(-)

diff --git a/io_uring/rw.c b/io_uring/rw.c
index e636be4850a7..4f7fa2520820 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -76,41 +76,24 @@ static int io_iov_buffer_select_prep(struct io_kiocb *req)
 	return 0;
 }
 
-static int __io_import_rw_buffer(int ddir, struct io_kiocb *req,
-			     struct io_async_rw *io,
-			     unsigned int issue_flags)
+static int io_import_vec(int ddir, struct io_kiocb *req,
+			 struct io_async_rw *io,
+			 const struct iovec __user *uvec,
+			 size_t uvec_segs)
 {
-	const struct io_issue_def *def = &io_issue_defs[req->opcode];
-	struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
+	int ret, nr_segs;
 	struct iovec *iov;
-	void __user *buf;
-	int nr_segs, ret;
-	size_t sqe_len;
-
-	buf = u64_to_user_ptr(rw->addr);
-	sqe_len = rw->len;
-
-	if (!def->vectored || req->flags & REQ_F_BUFFER_SELECT) {
-		if (io_do_buffer_select(req)) {
-			buf = io_buffer_select(req, &sqe_len, issue_flags);
-			if (!buf)
-				return -ENOBUFS;
-			rw->addr = (unsigned long) buf;
-			rw->len = sqe_len;
-		}
-
-		return import_ubuf(ddir, buf, sqe_len, &io->iter);
-	}
 
 	if (io->free_iovec) {
 		nr_segs = io->free_iov_nr;
 		iov = io->free_iovec;
 	} else {
-		iov = &io->fast_iov;
 		nr_segs = 1;
+		iov = &io->fast_iov;
 	}
-	ret = __import_iovec(ddir, buf, sqe_len, nr_segs, &iov, &io->iter,
-				io_is_compat(req->ctx));
+
+	ret = __import_iovec(ddir, uvec, uvec_segs, nr_segs, &iov, &io->iter,
+			     io_is_compat(req->ctx));
 	if (unlikely(ret < 0))
 		return ret;
 	if (iov) {
@@ -122,6 +105,28 @@ static int __io_import_rw_buffer(int ddir, struct io_kiocb *req,
 	return 0;
 }
 
+static int __io_import_rw_buffer(int ddir, struct io_kiocb *req,
+			     struct io_async_rw *io,
+			     unsigned int issue_flags)
+{
+	const struct io_issue_def *def = &io_issue_defs[req->opcode];
+	struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
+	void __user *buf = u64_to_user_ptr(rw->addr);
+	size_t sqe_len = rw->len;
+
+	if (def->vectored && !(req->flags & REQ_F_BUFFER_SELECT))
+		return io_import_vec(ddir, req, io, buf, sqe_len);
+
+	if (io_do_buffer_select(req)) {
+		buf = io_buffer_select(req, &sqe_len, issue_flags);
+		if (!buf)
+			return -ENOBUFS;
+		rw->addr = (unsigned long) buf;
+		rw->len = sqe_len;
+	}
+	return import_ubuf(ddir, buf, sqe_len, &io->iter);
+}
+
 static inline int io_import_rw_buffer(int rw, struct io_kiocb *req,
 				      struct io_async_rw *io,
 				      unsigned int issue_flags)
-- 
2.48.1