fuse: introduce fuse_simple_request() helper

The following pattern is repeated many times:

	req = fuse_get_req_nopages(fc);
	/* Initialize req->(in|out).args */
	fuse_request_send(fc, req);
	err = req->out.h.error;
	fuse_put_request(req);

Create a new replacement helper:

	/* Initialize args */
	err = fuse_simple_request(fc, &args);

In addition to reducing the code size, this will ease moving from the
complex arg-based to a simpler page-based I/O on the fuse device.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

1 files changed, 29 insertions, 0 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ca887314aba9..ba1107977f2e 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -511,6 +511,35 @@ void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
 }
 EXPORT_SYMBOL_GPL(fuse_request_send);
 
+ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
+{
+	struct fuse_req *req;
+	ssize_t ret;
+
+	req = fuse_get_req(fc, 0);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	req->in.h.opcode = args->in.h.opcode;
+	req->in.h.nodeid = args->in.h.nodeid;
+	req->in.numargs = args->in.numargs;
+	memcpy(req->in.args, args->in.args,
+	       args->in.numargs * sizeof(struct fuse_in_arg));
+	req->out.argvar = args->out.argvar;
+	req->out.numargs = args->out.numargs;
+	memcpy(req->out.args, args->out.args,
+	       args->out.numargs * sizeof(struct fuse_arg));
+	fuse_request_send(fc, req);
+	ret = req->out.h.error;
+	if (!ret && args->out.argvar) {
+		BUG_ON(args->out.numargs != 1);
+		ret = req->out.args[0].size;
+	}
+	fuse_put_request(fc, req);
+
+	return ret;
+}
+
 static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
 					    struct fuse_req *req)
 {