[PATCH RFC v5 08/16] fuse: Add fuse-io-uring handling into fuse_copy

[Bernd Schubert <bschubert@ddn.com>]

Add special fuse-io-uring into the fuse argument
copy handler.

Signed-off-by: Bernd Schubert <bschubert@ddn.com>
---
 fs/fuse/dev.c        | 12 +++++++++++-
 fs/fuse/fuse_dev_i.h |  5 +++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index f210f91a937b24e75a467e943cdec4581900e061..4ca67c8ae0e28072383478d6ee7ad7791566b6ce 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -738,6 +738,9 @@ static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
 	*size -= ncpy;
 	cs->len -= ncpy;
 	cs->offset += ncpy;
+	if (cs->is_uring)
+		cs->ring.offset += ncpy;
+
 	return ncpy;
 }
 
@@ -1872,7 +1875,14 @@ static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
 int fuse_copy_out_args(struct fuse_copy_state *cs, struct fuse_args *args,
 		       unsigned nbytes)
 {
-	unsigned reqsize = sizeof(struct fuse_out_header);
+
+	unsigned int reqsize = 0;
+
+	/*
+	 * Uring has all headers separated from args - args is payload only
+	 */
+	if (!cs->is_uring)
+		reqsize = sizeof(struct fuse_out_header);
 
 	reqsize += fuse_len_args(args->out_numargs, args->out_args);
 
diff --git a/fs/fuse/fuse_dev_i.h b/fs/fuse/fuse_dev_i.h
index f36e304cd62c8302aed95de89926fc894f602cfd..7ecb103af6f0feca99eb8940872c6a5ccf2e5186 100644
--- a/fs/fuse/fuse_dev_i.h
+++ b/fs/fuse/fuse_dev_i.h
@@ -28,6 +28,11 @@ struct fuse_copy_state {
 	unsigned int len;
 	unsigned int offset;
 	unsigned int move_pages:1;
+	unsigned int is_uring:1;
+	struct {
+		/* overall offset with the user buffer */
+		unsigned int offset;
+	} ring;
 };
 
 static inline struct fuse_dev *fuse_get_dev(struct file *file)

-- 
2.43.0