io_uring/rw: move buffer_select outside generic prep

Cleans up the generic rw prep to not require the do_import flag. Use a
different prep function for callers that might need buffer select.

Based-on-a-patch-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20250227223916.143006-2-kbusch@meta.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 28 insertions, 17 deletions

diff --git a/io_uring/rw.c b/io_uring/rw.c
index 788f06fbd7db..b21b423b3cf8 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -248,8 +248,8 @@ static int io_prep_rw_pi(struct io_kiocb *req, struct io_rw *rw, int ddir,
 	return ret;
 }
 
-static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
-		      int ddir, bool do_import)
+static int __io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
+			int ddir)
 {
 	struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
 	unsigned ioprio;
@@ -285,14 +285,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 	rw->len = READ_ONCE(sqe->len);
 	rw->flags = READ_ONCE(sqe->rw_flags);
 
-	if (do_import && !io_do_buffer_select(req)) {
-		struct io_async_rw *io = req->async_data;
-
-		ret = io_import_rw_buffer(ddir, req, io, 0);
-		if (unlikely(ret))
-			return ret;
-	}
-
 	attr_type_mask = READ_ONCE(sqe->attr_type_mask);
 	if (attr_type_mask) {
 		u64 attr_ptr;
@@ -307,26 +299,45 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 	return 0;
 }
 
+static int io_rw_do_import(struct io_kiocb *req, int ddir)
+{
+	if (io_do_buffer_select(req))
+		return 0;
+
+	return io_import_rw_buffer(ddir, req, req->async_data, 0);
+}
+
+static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
+		      int ddir)
+{
+	int ret;
+
+	ret = __io_prep_rw(req, sqe, ddir);
+	if (unlikely(ret))
+		return ret;
+
+	return io_rw_do_import(req, ddir);
+}
+
 int io_prep_read(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
-	return io_prep_rw(req, sqe, ITER_DEST, true);
+	return io_prep_rw(req, sqe, ITER_DEST);
 }
 
 int io_prep_write(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
-	return io_prep_rw(req, sqe, ITER_SOURCE, true);
+	return io_prep_rw(req, sqe, ITER_SOURCE);
 }
 
 static int io_prep_rwv(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		       int ddir)
 {
-	const bool do_import = !(req->flags & REQ_F_BUFFER_SELECT);
 	int ret;
 
-	ret = io_prep_rw(req, sqe, ddir, do_import);
+	ret = io_prep_rw(req, sqe, ddir);
 	if (unlikely(ret))
 		return ret;
-	if (do_import)
+	if (!(req->flags & REQ_F_BUFFER_SELECT))
 		return 0;
 
 	/*
@@ -353,7 +364,7 @@ static int io_prep_rw_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe
 	struct io_async_rw *io;
 	int ret;
 
-	ret = io_prep_rw(req, sqe, ddir, false);
+	ret = __io_prep_rw(req, sqe, ddir);
 	if (unlikely(ret))
 		return ret;
 
@@ -386,7 +397,7 @@ int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	if (!(req->flags & REQ_F_BUFFER_SELECT))
 		return -EINVAL;
 
-	ret = io_prep_rw(req, sqe, ITER_DEST, false);
+	ret = __io_prep_rw(req, sqe, ITER_DEST);
 	if (unlikely(ret))
 		return ret;