io_uring/rsrc: replace reg buffer bit field with flags

I'll need a flag in the registered buffer struct for dmabuf work, and
it'll be more convenient to have a flags field rather than bit fields,
especially for io_mapped_ubuf initialisation.

We might want to add more flags in the future as well. For example, it
might be useful for debugging and potentially optimisations to split out
a flag indicating the shape of the buffer to gate iov_iter_advance()
walks vs bit/mask arithmetics. It can also be combined with the
direction mask field.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 5 insertions, 1 deletions

diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 4a5db2ad1af2..cff0f8834c35 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -28,6 +28,10 @@ enum {
 	IO_IMU_SOURCE	= 1 << ITER_SOURCE,
 };
 
+enum {
+	IO_REGBUF_F_KBUF		= 1,
+};
+
 struct io_mapped_ubuf {
 	u64		ubuf;
 	unsigned int	len;
@@ -37,7 +41,7 @@ struct io_mapped_ubuf {
 	unsigned long	acct_pages;
 	void		(*release)(void *);
 	void		*priv;
-	bool		is_kbuf;
+	u8		flags;
 	u8		dir;
 	struct bio_vec	bvec[] __counted_by(nr_bvecs);
 };