[RFC PATCH 05/12] io_uring: export 'struct io_mapped_buf' for fused cmd buffer

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

Export 'struct io_mapped_buf' for the coming fused cmd buffer,
which is based on bvec too.

This instance is supposed to be immutable in its whole lifetime.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 include/linux/io_uring.h | 19 +++++++++++++++++++
 io_uring/rsrc.h          |  9 ---------
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index 934e5dd4ccc0..88205ea566d3 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -4,6 +4,7 @@
 
 #include <linux/sched.h>
 #include <linux/xarray.h>
+#include <linux/bvec.h>
 #include <uapi/linux/io_uring.h>
 
 enum io_uring_cmd_flags {
@@ -36,6 +37,24 @@ struct io_uring_cmd {
 	u8		pdu[32]; /* available inline for free use */
 };
 
+/* The mapper buffer is supposed to be immutable */
+struct io_mapped_buf {
+	u64		buf;
+	u64		buf_end;
+	unsigned int	nr_bvecs;
+	union {
+		unsigned int	acct_pages;
+
+		/*
+		 * offset into the bvecs, use for external user; with
+		 * 'offset', immutable bvecs can be provided for io_uring
+		 */
+		unsigned int	offset;
+	};
+	struct bio_vec	*bvec;
+	struct bio_vec	__bvec[];
+};
+
 #if defined(CONFIG_IO_URING)
 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 			      struct iov_iter *iter, void *ioucmd);
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 5da54702cad1..4bd17877d53a 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -45,15 +45,6 @@ struct io_rsrc_node {
 	bool				done;
 };
 
-struct io_mapped_buf {
-	u64		buf;
-	u64		buf_end;
-	unsigned int	nr_bvecs;
-	unsigned int	acct_pages;
-	struct bio_vec	*bvec;
-	struct bio_vec	__bvec[];
-};
-
 void io_rsrc_put_tw(struct callback_head *cb);
 void io_rsrc_put_work(struct work_struct *work);
 void io_rsrc_refs_refill(struct io_ring_ctx *ctx);
-- 
2.31.1