Refactor buffer import functions:
- Make io_import_fixed() global so BPF kfuncs can use it directly
- Make io_import_reg_buf() static inline in rsrc.h

This allows BPF kfuncs to import buffers without associating them
with a request, useful when one request has multiple buffers.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 io_uring/rsrc.c | 17 +++--------------
 io_uring/rsrc.h | 18 +++++++++++++++---
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 41c89f5c616d..8aa2f7473c89 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -1069,9 +1069,9 @@ static int io_import_kbuf(int ddir, struct iov_iter *iter,
 	return 0;
 }
 
-static int io_import_fixed(int ddir, struct iov_iter *iter,
-			   struct io_mapped_ubuf *imu,
-			   u64 buf_addr, size_t len)
+int io_import_fixed(int ddir, struct iov_iter *iter,
+		    struct io_mapped_ubuf *imu,
+		    u64 buf_addr, size_t len)
 {
 	const struct bio_vec *bvec;
 	size_t folio_mask;
@@ -1140,17 +1140,6 @@ inline struct io_rsrc_node *io_find_buf_node(struct io_kiocb *req,
 	return NULL;
 }
 
-int io_import_reg_buf(struct io_kiocb *req, struct iov_iter *iter,
-			u64 buf_addr, size_t len, int ddir,
-			unsigned issue_flags)
-{
-	struct io_rsrc_node *node;
-
-	node = io_find_buf_node(req, issue_flags);
-	if (!node)
-		return -EFAULT;
-	return io_import_fixed(ddir, iter, node->buf, buf_addr, len);
-}
 
 /* Lock two rings at once. The rings must be different! */
 static void lock_two_rings(struct io_ring_ctx *ctx1, struct io_ring_ctx *ctx2)
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index d603f6a47f5e..bf77bc618fb5 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -61,9 +61,21 @@ int io_rsrc_data_alloc(struct io_rsrc_data *data, unsigned nr);
 
 struct io_rsrc_node *io_find_buf_node(struct io_kiocb *req,
 				      unsigned issue_flags);
-int io_import_reg_buf(struct io_kiocb *req, struct iov_iter *iter,
-			u64 buf_addr, size_t len, int ddir,
-			unsigned issue_flags);
+int io_import_fixed(int ddir, struct iov_iter *iter,
+		    struct io_mapped_ubuf *imu,
+		    u64 buf_addr, size_t len);
+
+static inline int io_import_reg_buf(struct io_kiocb *req, struct iov_iter *iter,
+				    u64 buf_addr, size_t len, int ddir,
+				    unsigned issue_flags)
+{
+	struct io_rsrc_node *node;
+
+	node = io_find_buf_node(req, issue_flags);
+	if (!node)
+		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);
-- 
2.47.0