block/rnbd: server: private header with server structs and functions

This header describes main structs and functions used by rnbd-server
module, namely structs for managing sessions from different clients and
mapped (opened) devices.

Link: https://lore.kernel.org/r/20200511135131.27580-20-danil.kipnis@cloud.ionos.com
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/block/rnbd/rnbd-srv.h

@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RDMA Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#ifndef RNBD_SRV_H
+#define RNBD_SRV_H
+
+#include <linux/types.h>
+#include <linux/idr.h>
+#include <linux/kref.h>
+
+#include <rtrs.h>
+#include "rnbd-proto.h"
+#include "rnbd-log.h"
+
+struct rnbd_srv_session {
+	/* Entry inside global sess_list */
+	struct list_head        list;
+	struct rtrs_srv		*rtrs;
+	char			sessname[NAME_MAX];
+	int			queue_depth;
+	struct bio_set		sess_bio_set;
+
+	struct xarray		index_idr;
+	/* List of struct rnbd_srv_sess_dev */
+	struct list_head        sess_dev_list;
+	struct mutex		lock;
+	u8			ver;
+};
+
+struct rnbd_srv_dev {
+	/* Entry inside global dev_list */
+	struct list_head                list;
+	struct kobject                  dev_kobj;
+	struct kobject                  *dev_sessions_kobj;
+	struct kref                     kref;
+	char				id[NAME_MAX];
+	/* List of rnbd_srv_sess_dev structs */
+	struct list_head		sess_dev_list;
+	struct mutex			lock;
+	int				open_write_cnt;
+};
+
+/* Structure which binds N devices and N sessions */
+struct rnbd_srv_sess_dev {
+	/* Entry inside rnbd_srv_dev struct */
+	struct list_head		dev_list;
+	/* Entry inside rnbd_srv_session struct */
+	struct list_head		sess_list;
+	struct rnbd_dev			*rnbd_dev;
+	struct rnbd_srv_session		*sess;
+	struct rnbd_srv_dev		*dev;
+	struct kobject                  kobj;
+	u32                             device_id;
+	fmode_t                         open_flags;
+	struct kref			kref;
+	struct completion               *destroy_comp;
+	char				pathname[NAME_MAX];
+	enum rnbd_access_mode		access_mode;
+};
+
+/* rnbd-srv-sysfs.c */
+
+int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
+			      struct block_device *bdev,
+			      const char *dir_name);
+void rnbd_srv_destroy_dev_sysfs(struct rnbd_srv_dev *dev);
+int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev);
+void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev);
+int rnbd_srv_create_sysfs_files(void);
+void rnbd_srv_destroy_sysfs_files(void);
+void rnbd_destroy_sess_dev(struct rnbd_srv_sess_dev *sess_dev);
+
+#endif /* RNBD_SRV_H */