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

This header describes main structs and functions used by rnbd-client
module, mainly for managing RNBD sessions and mapped block devices,
creating and destroying sysfs entries.

Link: https://lore.kernel.org/r/20200511135131.27580-17-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>

diff --git a/drivers/block/rnbd/rnbd-clt.h b/drivers/block/rnbd/rnbd-clt.h
new file mode 100644 (file)
index 0000000..ed33654
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-clt.h
@@ -0,0 +1,156 @@
+/* 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_CLT_H
+#define RNBD_CLT_H
+
+#include <linux/wait.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/blk-mq.h>
+#include <linux/refcount.h>
+
+#include <rtrs.h>
+#include "rnbd-proto.h"
+#include "rnbd-log.h"
+
+/* Max. number of segments per IO request, Mellanox Connect X ~ Connect X5,
+ * choose minimial 30 for all, minus 1 for internal protocol, so 29.
+ */
+#define BMAX_SEGMENTS 29
+/*  time in seconds between reconnect tries, default to 30 s */
+#define RECONNECT_DELAY 30
+/*
+ * Number of times to reconnect on error before giving up, 0 for * disabled,
+ * -1 for forever
+ */
+#define MAX_RECONNECTS -1
+
+enum rnbd_clt_dev_state {
+       DEV_STATE_INIT,
+       DEV_STATE_MAPPED,
+       DEV_STATE_MAPPED_DISCONNECTED,
+       DEV_STATE_UNMAPPED,
+};
+
+struct rnbd_iu_comp {
+       wait_queue_head_t wait;
+       int errno;
+};
+
+struct rnbd_iu {
+       union {
+               struct request *rq; /* for block io */
+               void *buf; /* for user messages */
+       };
+       struct rtrs_permit      *permit;
+       union {
+               /* use to send msg associated with a dev */
+               struct rnbd_clt_dev *dev;
+               /* use to send msg associated with a sess */
+               struct rnbd_clt_session *sess;
+       };
+       struct scatterlist      sglist[BMAX_SEGMENTS];
+       struct work_struct      work;
+       int                     errno;
+       struct rnbd_iu_comp     comp;
+       atomic_t                refcount;
+};
+
+struct rnbd_cpu_qlist {
+       struct list_head        requeue_list;
+       spinlock_t              requeue_lock;
+       unsigned int            cpu;
+};
+
+struct rnbd_clt_session {
+       struct list_head        list;
+       struct rtrs_clt        *rtrs;
+       wait_queue_head_t       rtrs_waitq;
+       bool                    rtrs_ready;
+       struct rnbd_cpu_qlist   __percpu
+                               *cpu_queues;
+       DECLARE_BITMAP(cpu_queues_bm, NR_CPUS);
+       int     __percpu        *cpu_rr; /* per-cpu var for CPU round-robin */
+       atomic_t                busy;
+       int                     queue_depth;
+       u32                     max_io_size;
+       struct blk_mq_tag_set   tag_set;
+       struct mutex            lock; /* protects state and devs_list */
+       struct list_head        devs_list; /* list of struct rnbd_clt_dev */
+       refcount_t              refcount;
+       char                    sessname[NAME_MAX];
+       u8                      ver; /* protocol version */
+};
+
+/**
+ * Submission queues.
+ */
+struct rnbd_queue {
+       struct list_head        requeue_list;
+       unsigned long           in_list;
+       struct rnbd_clt_dev     *dev;
+       struct blk_mq_hw_ctx    *hctx;
+};
+
+struct rnbd_clt_dev {
+       struct rnbd_clt_session *sess;
+       struct request_queue    *queue;
+       struct rnbd_queue       *hw_queues;
+       u32                     device_id;
+       /* local Idr index - used to track minor number allocations. */
+       u32                     clt_device_id;
+       struct mutex            lock;
+       enum rnbd_clt_dev_state dev_state;
+       char                    pathname[NAME_MAX];
+       enum rnbd_access_mode   access_mode;
+       bool                    read_only;
+       bool                    rotational;
+       u32                     max_hw_sectors;
+       u32                     max_write_same_sectors;
+       u32                     max_discard_sectors;
+       u32                     discard_granularity;
+       u32                     discard_alignment;
+       u16                     secure_discard;
+       u16                     physical_block_size;
+       u16                     logical_block_size;
+       u16                     max_segments;
+       size_t                  nsectors;
+       u64                     size;           /* device size in bytes */
+       struct list_head        list;
+       struct gendisk          *gd;
+       struct kobject          kobj;
+       char                    blk_symlink_name[NAME_MAX];
+       refcount_t              refcount;
+       struct work_struct      unmap_on_rmmod_work;
+};
+
+/* rnbd-clt.c */
+
+struct rnbd_clt_dev *rnbd_clt_map_device(const char *sessname,
+                                          struct rtrs_addr *paths,
+                                          size_t path_cnt, u16 port_nr,
+                                          const char *pathname,
+                                          enum rnbd_access_mode access_mode);
+int rnbd_clt_unmap_device(struct rnbd_clt_dev *dev, bool force,
+                          const struct attribute *sysfs_self);
+
+int rnbd_clt_remap_device(struct rnbd_clt_dev *dev);
+int rnbd_clt_resize_disk(struct rnbd_clt_dev *dev, size_t newsize);
+
+/* rnbd-clt-sysfs.c */
+
+int rnbd_clt_create_sysfs_files(void);
+
+void rnbd_clt_destroy_sysfs_files(void);
+void rnbd_clt_destroy_default_group(void);
+
+void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev);
+
+#endif /* RNBD_CLT_H */