--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2015 XSky <haomai@xsky.com>
+ *
+ * Author: Haomai Wang <haomaiwang@gmail.com>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+#ifndef CEPH_OS_BLUESTORE_BLOCKDEVICE_H
+#define CEPH_OS_BLUESTORE_BLOCKDEVICE_H
+
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+#include <list>
+
+#include "acconfig.h"
+#include "aio.h"
+
+#define SPDK_PREFIX "spdk:"
+
+/// track in-flight io
+struct IOContext {
+private:
+ std::mutex lock;
+ std::condition_variable cond;
+
+public:
+ CephContext* cct;
+ void *priv;
+#ifdef HAVE_SPDK
+ void *nvme_task_first = nullptr;
+ void *nvme_task_last = nullptr;
+#endif
+
+
+ std::list<aio_t> pending_aios; ///< not yet submitted
+ std::list<aio_t> running_aios; ///< submitting or submitted
+ std::atomic_int num_pending = {0};
+ std::atomic_int num_running = {0};
+
+ explicit IOContext(CephContext* cct, void *p)
+ : cct(cct), priv(p)
+ {}
+
+ // no copying
+ IOContext(const IOContext& other) = delete;
+ IOContext &operator=(const IOContext& other) = delete;
+
+ bool has_pending_aios() {
+ return num_pending.load();
+ }
+
+ void aio_wait();
+
+ void try_aio_wake() {
+ if (num_running == 1) {
+
+ // we might have some pending IOs submitted after the check
+ // as there is no lock protection for aio_submit.
+ // Hence we might have false conditional trigger.
+ // aio_wait has to handle that hence do not care here.
+ std::lock_guard<std::mutex> l(lock);
+ cond.notify_all();
+ --num_running;
+ assert(num_running >= 0);
+ } else {
+ --num_running;
+ }
+ }
+};
+
+
+class BlockDevice {
+public:
+ CephContext* cct;
+private:
+ std::mutex ioc_reap_lock;
+ std::vector<IOContext*> ioc_reap_queue;
+ std::atomic_int ioc_reap_count = {0};
+
+protected:
+ bool rotational = true;
+
+public:
+ BlockDevice(CephContext* cct) : cct(cct) {}
+ virtual ~BlockDevice() = default;
+ typedef void (*aio_callback_t)(void *handle, void *aio);
+
+ static BlockDevice *create(
+ CephContext* cct, const std::string& path, aio_callback_t cb, void *cbpriv);
+ virtual bool supported_bdev_label() { return true; }
+ virtual bool is_rotational() { return rotational; }
+
+ virtual void aio_submit(IOContext *ioc) = 0;
+
+ virtual uint64_t get_size() const = 0;
+ virtual uint64_t get_block_size() const = 0;
+
+ virtual int collect_metadata(std::string prefix, std::map<std::string,std::string> *pm) const = 0;
+
+ virtual int read(
+ uint64_t off,
+ uint64_t len,
+ bufferlist *pbl,
+ IOContext *ioc,
+ bool buffered) = 0;
+ virtual int read_random(
+ uint64_t off,
+ uint64_t len,
+ char *buf,
+ bool buffered) = 0;
+ virtual int write(
+ uint64_t off,
+ bufferlist& bl,
+ bool buffered) = 0;
+
+ virtual int aio_read(
+ uint64_t off,
+ uint64_t len,
+ bufferlist *pbl,
+ IOContext *ioc) = 0;
+ virtual int aio_write(
+ uint64_t off,
+ bufferlist& bl,
+ IOContext *ioc,
+ bool buffered) = 0;
+ virtual int flush() = 0;
+
+ void queue_reap_ioc(IOContext *ioc);
+ void reap_ioc();
+
+ // for managing buffered readers/writers
+ virtual int invalidate_cache(uint64_t off, uint64_t len) = 0;
+ virtual int open(const std::string& path) = 0;
+ virtual void close() = 0;
+};
+
+#endif //CEPH_OS_BLUESTORE_BLOCKDEVICE_H