initial code repo

[stor4nfv.git] / src / ceph / src / librbd / io / ImageRequestWQ.h

diff --git a/src/ceph/src/librbd/io/ImageRequestWQ.h b/src/ceph/src/librbd/io/ImageRequestWQ.h
new file mode 100644 (file)
index 0000000..ad51b0f
--- /dev/null
+++ b/src/ceph/src/librbd/io/ImageRequestWQ.h
@@ -0,0 +1,128 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_IO_IMAGE_REQUEST_WQ_H
+#define CEPH_LIBRBD_IO_IMAGE_REQUEST_WQ_H
+
+#include "include/Context.h"
+#include "common/RWLock.h"
+#include "common/WorkQueue.h"
+#include "librbd/io/Types.h"
+
+#include <list>
+#include <atomic>
+
+namespace librbd {
+
+class ImageCtx;
+
+namespace io {
+
+class AioCompletion;
+template <typename> class ImageRequest;
+class ReadResult;
+
+template <typename ImageCtxT = librbd::ImageCtx>
+class ImageRequestWQ
+  : public ThreadPool::PointerWQ<ImageRequest<ImageCtxT> > {
+public:
+  ImageRequestWQ(ImageCtxT *image_ctx, const string &name, time_t ti,
+                 ThreadPool *tp);
+
+  ssize_t read(uint64_t off, uint64_t len, ReadResult &&read_result,
+               int op_flags);
+  ssize_t write(uint64_t off, uint64_t len, bufferlist &&bl, int op_flags);
+  ssize_t discard(uint64_t off, uint64_t len, bool skip_partial_discard);
+  ssize_t writesame(uint64_t off, uint64_t len, bufferlist &&bl, int op_flags);
+  ssize_t compare_and_write(uint64_t off, uint64_t len,
+                            bufferlist &&cmp_bl, bufferlist &&bl,
+                            uint64_t *mismatch_off, int op_flags);
+
+  void aio_read(AioCompletion *c, uint64_t off, uint64_t len,
+                ReadResult &&read_result, int op_flags, bool native_async=true);
+  void aio_write(AioCompletion *c, uint64_t off, uint64_t len,
+                 bufferlist &&bl, int op_flags, bool native_async=true);
+  void aio_discard(AioCompletion *c, uint64_t off, uint64_t len,
+                   bool skip_partial_discard, bool native_async=true);
+  void aio_flush(AioCompletion *c, bool native_async=true);
+  void aio_writesame(AioCompletion *c, uint64_t off, uint64_t len,
+                     bufferlist &&bl, int op_flags, bool native_async=true);
+  void aio_compare_and_write(AioCompletion *c, uint64_t off,
+                             uint64_t len, bufferlist &&cmp_bl,
+                             bufferlist &&bl, uint64_t *mismatch_off,
+                             int op_flags, bool native_async=true);
+
+  using ThreadPool::PointerWQ<ImageRequest<ImageCtxT> >::drain;
+
+  using ThreadPool::PointerWQ<ImageRequest<ImageCtxT> >::empty;
+
+  void shut_down(Context *on_shutdown);
+
+  inline bool writes_blocked() const {
+    RWLock::RLocker locker(m_lock);
+    return (m_write_blockers > 0);
+  }
+
+  int block_writes();
+  void block_writes(Context *on_blocked);
+  void unblock_writes();
+
+  void set_require_lock(Direction direction, bool enabled);
+
+protected:
+  void *_void_dequeue() override;
+  void process(ImageRequest<ImageCtxT> *req) override;
+
+private:
+  typedef std::list<Context *> Contexts;
+
+  struct C_AcquireLock;
+  struct C_BlockedWrites;
+  struct C_RefreshFinish;
+
+  ImageCtxT &m_image_ctx;
+  mutable RWLock m_lock;
+  Contexts m_write_blocker_contexts;
+  uint32_t m_write_blockers = 0;
+  bool m_require_lock_on_read = false;
+  bool m_require_lock_on_write = false;
+  std::atomic<unsigned> m_queued_reads { 0 };
+  std::atomic<unsigned> m_queued_writes { 0 };
+  std::atomic<unsigned> m_in_flight_ios { 0 };
+  std::atomic<unsigned> m_in_flight_writes { 0 };
+  std::atomic<unsigned> m_io_blockers { 0 };
+
+  bool m_shutdown = false;
+  Context *m_on_shutdown = nullptr;
+
+  bool is_lock_required(bool write_op) const;
+
+  inline bool require_lock_on_read() const {
+    RWLock::RLocker locker(m_lock);
+    return m_require_lock_on_read;
+  }
+  inline bool writes_empty() const {
+    RWLock::RLocker locker(m_lock);
+    return (m_queued_writes == 0);
+  }
+
+  void finish_queued_io(ImageRequest<ImageCtxT> *req);
+  void finish_in_flight_write();
+
+  int start_in_flight_io(AioCompletion *c);
+  void finish_in_flight_io();
+  void fail_in_flight_io(int r, ImageRequest<ImageCtxT> *req);
+
+  void queue(ImageRequest<ImageCtxT> *req);
+
+  void handle_acquire_lock(int r, ImageRequest<ImageCtxT> *req);
+  void handle_refreshed(int r, ImageRequest<ImageCtxT> *req);
+  void handle_blocked_writes(int r);
+};
+
+} // namespace io
+} // namespace librbd
+
+extern template class librbd::io::ImageRequestWQ<librbd::ImageCtx>;
+
+#endif // CEPH_LIBRBD_IO_IMAGE_REQUEST_WQ_H