1 files changed, 280 insertions, 0 deletions
diff --git a/src/librbd/cache/pwl/LogEntry.h b/src/librbd/cache/pwl/LogEntry.h
new file mode 100644
index 000000000..ecaca0b7b
--- /dev/null
+++ b/src/librbd/cache/pwl/LogEntry.h
@@ -0,0 +1,280 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_LIBRBD_CACHE_PWL_LOG_ENTRY_H
+#define CEPH_LIBRBD_CACHE_PWL_LOG_ENTRY_H
+
+#include "common/ceph_mutex.h"
+#include "librbd/Utils.h"
+#include "librbd/cache/pwl/Types.h"
+#include <atomic>
+#include <memory>
+
+namespace librbd {
+namespace cache {
+class ImageWritebackInterface;
+namespace pwl {
+
+class SyncPointLogEntry;
+class GenericWriteLogEntry;
+class WriteLogEntry;
+
+typedef std::list<std::shared_ptr<GenericWriteLogEntry>> GenericWriteLogEntries;
+
+class GenericLogEntry {
+public:
+  WriteLogCacheEntry ram_entry;
+  WriteLogCacheEntry *cache_entry = nullptr;
+  uint64_t log_entry_index = 0;
+  bool completed = false;
+  BlockGuardCell* m_cell = nullptr;
+  GenericLogEntry(uint64_t image_offset_bytes = 0, uint64_t write_bytes = 0)
+    : ram_entry(image_offset_bytes, write_bytes) {
+  };
+  virtual ~GenericLogEntry() { };
+  GenericLogEntry(const GenericLogEntry&) = delete;
+  GenericLogEntry &operator=(const GenericLogEntry&) = delete;
+  virtual bool can_writeback() const {
+    return false;
+  }
+  virtual bool can_retire() const {
+    return false;
+  }
+  virtual void set_flushed(bool flushed) {
+    ceph_assert(false);
+  }
+  virtual unsigned int write_bytes() const {
+    return 0;
+  };
+  virtual unsigned int bytes_dirty() const {
+    return 0;
+  };
+  virtual std::shared_ptr<SyncPointLogEntry> get_sync_point_entry() {
+    return nullptr;
+  }
+  virtual void writeback(librbd::cache::ImageWritebackInterface &image_writeback,
+                         Context *ctx) {
+    ceph_assert(false);
+  };
+  virtual void writeback_bl(librbd::cache::ImageWritebackInterface &image_writeback,
+                 Context *ctx, ceph::bufferlist &&bl) {
+    ceph_assert(false);
+  }
+  virtual bool is_write_entry() const {
+    return false;
+  }
+  virtual bool is_writesame_entry() const {
+    return false;
+  }
+  virtual bool is_sync_point() const {
+    return false;
+  }
+  virtual unsigned int get_aligned_data_size() const {
+    return 0;
+  }
+  virtual void remove_cache_bl() {}
+  virtual std::ostream& format(std::ostream &os) const;
+  friend std::ostream &operator<<(std::ostream &os,
+                                  const GenericLogEntry &entry);
+};
+
+class SyncPointLogEntry : public GenericLogEntry {
+public:
+  /* Writing entries using this sync gen number */
+  std::atomic<unsigned int> writes = {0};
+  /* Total bytes for all writing entries using this sync gen number */
+  std::atomic<uint64_t> bytes = {0};
+  /* Writing entries using this sync gen number that have completed */
+  std::atomic<unsigned int> writes_completed = {0};
+  /* Writing entries using this sync gen number that have completed flushing to the writeback interface */
+  std::atomic<unsigned int> writes_flushed = {0};
+  /* All writing entries using all prior sync gen numbers have been flushed */
+  std::atomic<bool> prior_sync_point_flushed = {true};
+  std::shared_ptr<SyncPointLogEntry> next_sync_point_entry = nullptr;
+  SyncPointLogEntry(uint64_t sync_gen_number) {
+    ram_entry.sync_gen_number = sync_gen_number;
+    ram_entry.set_sync_point(true);
+  };
+  ~SyncPointLogEntry() override {};
+  SyncPointLogEntry(const SyncPointLogEntry&) = delete;
+  SyncPointLogEntry &operator=(const SyncPointLogEntry&) = delete;
+  bool can_retire() const override {
+    return this->completed;
+  }
+  bool is_sync_point() const override {
+    return true;
+  }
+  std::ostream& format(std::ostream &os) const;
+  friend std::ostream &operator<<(std::ostream &os,
+                                  const SyncPointLogEntry &entry);
+};
+
+class GenericWriteLogEntry : public GenericLogEntry {
+public:
+  uint32_t referring_map_entries = 0;
+  std::shared_ptr<SyncPointLogEntry> sync_point_entry;
+  GenericWriteLogEntry(std::shared_ptr<SyncPointLogEntry> sync_point_entry,
+                       uint64_t image_offset_bytes, uint64_t write_bytes)
+    : GenericLogEntry(image_offset_bytes, write_bytes), sync_point_entry(sync_point_entry) { }
+  GenericWriteLogEntry(uint64_t image_offset_bytes, uint64_t write_bytes)
+    : GenericLogEntry(image_offset_bytes, write_bytes), sync_point_entry(nullptr) { }
+  ~GenericWriteLogEntry() override {};
+  GenericWriteLogEntry(const GenericWriteLogEntry&) = delete;
+  GenericWriteLogEntry &operator=(const GenericWriteLogEntry&) = delete;
+  unsigned int write_bytes() const override {
+    /* The valid bytes in this ops data buffer. Discard and WS override. */
+    return ram_entry.write_bytes;
+  };
+  unsigned int bytes_dirty() const override {
+    /* The bytes in the image this op makes dirty. Discard and WS override. */
+    return write_bytes();
+  };
+  BlockExtent block_extent() {
+    return ram_entry.block_extent();
+  }
+  uint32_t get_map_ref() {
+    return(referring_map_entries);
+  }
+  void inc_map_ref() { referring_map_entries++; }
+  void dec_map_ref() { referring_map_entries--; }
+  bool can_writeback() const override;
+  std::shared_ptr<SyncPointLogEntry> get_sync_point_entry() override {
+    return sync_point_entry;
+  }
+  virtual void copy_cache_bl(bufferlist *out_bl) = 0;
+  void set_flushed(bool flushed) override {
+    m_flushed = flushed;
+  }
+  bool get_flushed() const {
+    return m_flushed;
+  }
+  std::ostream &format(std::ostream &os) const;
+  friend std::ostream &operator<<(std::ostream &os,
+                                  const GenericWriteLogEntry &entry);
+
+private:
+  bool m_flushed = false; /* or invalidated */
+};
+
+class WriteLogEntry : public GenericWriteLogEntry {
+protected:
+  bool is_writesame = false;
+  buffer::ptr cache_bp;
+  buffer::list cache_bl;
+  std::atomic<int> bl_refs = {0}; /* The refs held on cache_bp by cache_bl */
+  /* Used in WriteLogEntry::get_cache_bl() to syncronize between threads making entries readable */
+  mutable ceph::mutex m_entry_bl_lock;
+
+  virtual void init_cache_bp() {}
+
+  virtual void init_bl(buffer::ptr &bp, buffer::list &bl) {}
+public:
+  uint8_t *cache_buffer = nullptr;
+  WriteLogEntry(std::shared_ptr<SyncPointLogEntry> sync_point_entry,
+                uint64_t image_offset_bytes, uint64_t write_bytes)
+    : GenericWriteLogEntry(sync_point_entry, image_offset_bytes, write_bytes),
+      m_entry_bl_lock(ceph::make_mutex(pwl::unique_lock_name(
+        "librbd::cache::pwl::WriteLogEntry::m_entry_bl_lock", this)))
+  { }
+  WriteLogEntry(uint64_t image_offset_bytes, uint64_t write_bytes)
+    : GenericWriteLogEntry(nullptr, image_offset_bytes, write_bytes),
+      m_entry_bl_lock(ceph::make_mutex(pwl::unique_lock_name(
+        "librbd::cache::pwl::WriteLogEntry::m_entry_bl_lock", this)))
+  { }
+  WriteLogEntry(std::shared_ptr<SyncPointLogEntry> sync_point_entry,
+                    uint64_t image_offset_bytes, uint64_t write_bytes,
+                    uint32_t data_length)
+    : WriteLogEntry(sync_point_entry, image_offset_bytes, write_bytes) {
+    ram_entry.set_writesame(true);
+    ram_entry.ws_datalen = data_length;
+    is_writesame = true;
+  };
+  WriteLogEntry(uint64_t image_offset_bytes, uint64_t write_bytes,
+                    uint32_t data_length)
+    : WriteLogEntry(nullptr, image_offset_bytes, write_bytes) {
+    ram_entry.set_writesame(true);
+    ram_entry.ws_datalen = data_length;
+    is_writesame = true;
+  };
+ ~WriteLogEntry() override {};
+  WriteLogEntry(const WriteLogEntry&) = delete;
+  WriteLogEntry &operator=(const WriteLogEntry&) = delete;
+  unsigned int write_bytes() const override {
+    // The valid bytes in this ops data buffer.
+    if(is_writesame) {
+      return ram_entry.ws_datalen;
+    }
+    return ram_entry.write_bytes;
+  };
+  unsigned int bytes_dirty() const override {
+    // The bytes in the image this op makes dirty.
+    return ram_entry.write_bytes;
+  };
+  void init(bool has_data,
+            uint64_t current_sync_gen, uint64_t last_op_sequence_num, bool persist_on_flush);
+  virtual void init_cache_buffer(std::vector<WriteBufferAllocation>::iterator allocation) {}
+  virtual void init_cache_bl(bufferlist &src_bl, uint64_t off, uint64_t len) {}
+  /* Returns a ref to a bl containing bufferptrs to the entry cache buffer */
+  virtual buffer::list &get_cache_bl() = 0;
+
+  BlockExtent block_extent();
+  virtual unsigned int reader_count() const = 0;
+  /* Constructs a new bl containing copies of cache_bp */
+  bool can_retire() const override {
+    return (this->completed && this->get_flushed() && (0 == reader_count()));
+  }
+  bool is_write_entry() const override {
+    return true;
+  }
+  bool is_writesame_entry() const override {
+    return is_writesame;
+  }
+  std::ostream &format(std::ostream &os) const;
+  friend std::ostream &operator<<(std::ostream &os,
+                                  const WriteLogEntry &entry);
+};
+
+class DiscardLogEntry : public GenericWriteLogEntry {
+public:
+  DiscardLogEntry(std::shared_ptr<SyncPointLogEntry> sync_point_entry,
+                  uint64_t image_offset_bytes, uint64_t write_bytes,
+                  uint32_t discard_granularity_bytes)
+    : GenericWriteLogEntry(sync_point_entry, image_offset_bytes, write_bytes),
+      m_discard_granularity_bytes(discard_granularity_bytes) {
+    ram_entry.set_discard(true);
+  };
+  DiscardLogEntry(uint64_t image_offset_bytes, uint64_t write_bytes)
+    : GenericWriteLogEntry(nullptr, image_offset_bytes, write_bytes) {
+    ram_entry.set_discard(true);
+  };
+  DiscardLogEntry(const DiscardLogEntry&) = delete;
+  DiscardLogEntry &operator=(const DiscardLogEntry&) = delete;
+  unsigned int write_bytes() const override {
+    /* The valid bytes in this ops data buffer. */
+    return 0;
+  };
+  unsigned int bytes_dirty() const override {
+    /* The bytes in the image this op makes dirty. */
+    return ram_entry.write_bytes;
+  };
+  bool can_retire() const override {
+    return this->completed;
+  }
+  void copy_cache_bl(bufferlist *out_bl) override {
+    ceph_assert(false);
+  }
+  void writeback(librbd::cache::ImageWritebackInterface &image_writeback,
+                 Context *ctx) override;
+  void init(uint64_t current_sync_gen, bool persist_on_flush, uint64_t last_op_sequence_num);
+  std::ostream &format(std::ostream &os) const;
+  friend std::ostream &operator<<(std::ostream &os,
+                                  const DiscardLogEntry &entry);
+private:
+  uint32_t m_discard_granularity_bytes;
+};
+
+} // namespace pwl
+} // namespace cache
+} // namespace librbd
+
+#endif // CEPH_LIBRBD_CACHE_PWL_LOG_ENTRY_H