[PATCH V2 03/13] io_uring: refactor io_import_reg_vec() for BPF kfunc use

[Ming Lei <ming.lei@redhat.com>]

Split io_import_reg_vec() into:
- __io_import_reg_vec(): core logic taking io_mapped_ubuf directly
- io_import_reg_vec(): inline wrapper handling buffer lookup and
  request flags

The core function takes 'imu' and 'need_clean' parameters instead of
accessing req directly. This allows BPF kfuncs to import vectored
buffers without request association, enabling support for multiple
buffers per request.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 io_uring/rsrc.c | 18 +++++-------------
 io_uring/rsrc.h | 29 ++++++++++++++++++++++++++---
 2 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index ec716e14d467..7eb2c70185e4 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -1476,23 +1476,14 @@ static int io_kern_bvec_size(struct iovec *iov, unsigned nr_iovs,
 	return 0;
 }
 
-int io_import_reg_vec(int ddir, struct iov_iter *iter,
-			struct io_kiocb *req, struct iou_vec *vec,
-			unsigned nr_iovs, unsigned issue_flags)
+int __io_import_reg_vec(int ddir, struct iov_iter *iter,
+			struct io_mapped_ubuf *imu, struct iou_vec *vec,
+			unsigned nr_iovs, bool *need_clean)
 {
-	struct io_rsrc_node *node;
-	struct io_mapped_ubuf *imu;
 	unsigned iovec_off;
 	struct iovec *iov;
 	unsigned nr_segs;
 
-	node = io_find_buf_node(req, issue_flags);
-	if (!node)
-		return -EFAULT;
-	imu = node->buf;
-	if (!(imu->dir & (1 << ddir)))
-		return -EFAULT;
-
 	iovec_off = vec->nr - nr_iovs;
 	iov = vec->iovec + iovec_off;
 
@@ -1531,7 +1522,8 @@ int io_import_reg_vec(int ddir, struct iov_iter *iter,
 
 		*vec = tmp_vec;
 		iov = vec->iovec + iovec_off;
-		req->flags |= REQ_F_NEED_CLEANUP;
+		if (need_clean)
+			*need_clean = true;
 	}
 
 	if (imu->is_kbuf)
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 2a29da350727..3203277ac289 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -77,9 +77,32 @@ static inline int io_import_reg_buf(struct io_kiocb *req, struct iov_iter *iter,
 		return -EFAULT;
 	return io_import_fixed(ddir, iter, node->buf, buf_addr, len);
 }
-int io_import_reg_vec(int ddir, struct iov_iter *iter,
-			struct io_kiocb *req, struct iou_vec *vec,
-			unsigned nr_iovs, unsigned issue_flags);
+int __io_import_reg_vec(int ddir, struct iov_iter *iter,
+			struct io_mapped_ubuf *imu, struct iou_vec *vec,
+			unsigned nr_iovs, bool *need_clean);
+
+static inline int io_import_reg_vec(int ddir, struct iov_iter *iter,
+				    struct io_kiocb *req, struct iou_vec *vec,
+				    unsigned nr_iovs, unsigned issue_flags)
+{
+	struct io_rsrc_node *node;
+	struct io_mapped_ubuf *imu;
+	bool need_clean = false;
+	int ret;
+
+	node = io_find_buf_node(req, issue_flags);
+	if (!node)
+		return -EFAULT;
+	imu = node->buf;
+	if (!(imu->dir & (1 << ddir)))
+		return -EFAULT;
+
+	ret = __io_import_reg_vec(ddir, iter, imu, vec, nr_iovs, &need_clean);
+	if (need_clean)
+		req->flags |= REQ_F_NEED_CLEANUP;
+	return ret;
+}
+
 int __io_prep_reg_iovec(struct iou_vec *iv, const struct iovec __user *uvec,
 			size_t uvec_segs, bool compat, bool *need_clean);
 
-- 
2.47.0