Allow applications to retrieve the req payload (io-uring only)

With io-uring the req owns the payload buffer, the application
can directly access it and copy data into it.

fuse_buf_copy_one() already has a check for dstmem == srcmem
and skips data copies.

fuse_reply_data
   fuse_reply_data_uring
       fuse_buf_copy
           fuse_buf_copy_one

Signed-off-by: Bernd Schubert <bschubert@ddn.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 6afcecd..e4544df 100644
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -3317,6 +3317,18 @@ bool fuse_req_is_uring(fuse_req_t req)
 	return req->is_uring;
 }
 
+#ifndef HAVE_URING
+int fuse_req_get_payload(fuse_req_t req, char **payload, size_t *payload_sz,
+			 void **mr)
+{
+	(void)req;
+	(void)payload;
+	(void)payload_sz;
+	(void)mr;
+	return -ENOTSUP;
+}
+#endif
+
 static struct {
 	void (*func)(fuse_req_t req, const fuse_ino_t node, const void *arg);
 	const char *name;