Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 602 insertions, 0 deletions

diff --git a/src/cls/2pc_queue/cls_2pc_queue.cc b/src/cls/2pc_queue/cls_2pc_queue.cc
new file mode 100644
index 000000000..fba763955
--- /dev/null
+++ b/src/cls/2pc_queue/cls_2pc_queue.cc
@@ -0,0 +1,602 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "include/types.h"
+
+#include "cls/2pc_queue/cls_2pc_queue_types.h"
+#include "cls/2pc_queue/cls_2pc_queue_ops.h"
+#include "cls/2pc_queue/cls_2pc_queue_const.h"
+#include "cls/queue/cls_queue_ops.h"
+#include "cls/queue/cls_queue_src.h"
+#include "objclass/objclass.h"
+
+CLS_VER(1,0)
+CLS_NAME(2pc_queue)
+
+using ceph::bufferlist;
+using ceph::decode;
+using ceph::encode;
+
+constexpr auto CLS_QUEUE_URGENT_DATA_XATTR_NAME = "cls_queue_urgent_data";
+
+static int cls_2pc_queue_init(cls_method_context_t hctx, bufferlist *in, bufferlist *out) {
+  auto in_iter = in->cbegin();
+
+  cls_queue_init_op op;
+  try {
+    decode(op, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_init: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+
+  cls_2pc_urgent_data urgent_data;
+
+  cls_queue_init_op init_op;
+
+  CLS_LOG(20, "INFO: cls_2pc_queue_init: max size is %lu (bytes)", op.queue_size);
+
+  init_op.queue_size = op.queue_size;
+  init_op.max_urgent_data_size = 23552; // overall head is 24KB ~ pending 1K reservations ops
+  encode(urgent_data, init_op.bl_urgent_data);
+
+  return queue_init(hctx, init_op);
+}
+
+static int cls_2pc_queue_get_capacity(cls_method_context_t hctx, bufferlist *in, bufferlist *out)
+{
+  cls_queue_get_capacity_ret op_ret;
+  auto ret = queue_get_capacity(hctx, op_ret);
+  if (ret < 0) {
+    return ret;
+  }
+
+  encode(op_ret, *out);
+  return 0;
+}
+
+static int cls_2pc_queue_reserve(cls_method_context_t hctx, bufferlist *in, bufferlist *out) {
+  cls_2pc_queue_reserve_op res_op;
+  try {
+    auto in_iter = in->cbegin();
+    decode(res_op, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+
+  if (res_op.size == 0) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: cannot reserve zero bytes");
+    return -EINVAL;
+  }
+  if (res_op.entries == 0) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: cannot reserve zero entries");
+    return -EINVAL;
+  }
+
+  // get head
+  cls_queue_head head;
+  int ret = queue_read_head(hctx, head);
+  if (ret < 0) {
+    return ret;
+  }
+
+  cls_2pc_urgent_data urgent_data;
+  try {
+    auto in_iter = head.bl_urgent_data.cbegin();
+    decode(urgent_data, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+
+  const auto overhead = res_op.entries*QUEUE_ENTRY_OVERHEAD;
+  const auto remaining_size = (head.tail.offset >= head.front.offset) ?
+    (head.queue_size - head.tail.offset) + (head.front.offset - head.max_head_size) :
+    head.front.offset - head.tail.offset;  
+
+
+  if (res_op.size + urgent_data.reserved_size + overhead > remaining_size) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: reservations exceeded maximum capacity");
+    CLS_LOG(10, "INFO: cls_2pc_queue_reserve: remaining size: %lu (bytes)", remaining_size);
+    CLS_LOG(10, "INFO: cls_2pc_queue_reserve: current reservations: %lu (bytes)", urgent_data.reserved_size);
+    CLS_LOG(10, "INFO: cls_2pc_queue_reserve: requested size: %lu (bytes)", res_op.size);
+    return -ENOSPC;
+  }
+
+  urgent_data.reserved_size += res_op.size + overhead;
+  // note that last id is incremented regadless of failures
+  // to avoid "old reservation" issues below
+  ++urgent_data.last_id;
+  bool result;
+  cls_2pc_reservations::iterator last_reservation;
+  std::tie(last_reservation, result) = urgent_data.reservations.emplace(std::piecewise_construct,
+          std::forward_as_tuple(urgent_data.last_id),
+          std::forward_as_tuple(res_op.size, ceph::coarse_real_clock::now()));
+  if (!result) {
+    // an old reservation that was never committed or aborted is in the map
+    // caller should try again assuming other IDs are ok
+    CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: reservation id conflict after rollover: %u", urgent_data.last_id);
+    return -EAGAIN;
+  }
+
+  // write back head
+  head.bl_urgent_data.clear();
+  encode(urgent_data, head.bl_urgent_data);
+
+  const uint64_t urgent_data_length = head.bl_urgent_data.length();
+
+  if (head.max_urgent_data_size < urgent_data_length) {
+    CLS_LOG(10, "INFO: cls_2pc_queue_reserve: urgent data size: %lu exceeded maximum: %lu using xattrs", urgent_data_length, head.max_urgent_data_size);
+    // add the last reservation to xattrs 
+    bufferlist bl_xattrs;
+    auto ret = cls_cxx_getxattr(hctx, CLS_QUEUE_URGENT_DATA_XATTR_NAME, &bl_xattrs);
+    if (ret < 0 && (ret != -ENOENT && ret != -ENODATA)) {
+      CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: failed to read xattrs with: %d", ret);
+      return ret;
+    }
+    cls_2pc_reservations xattr_reservations;
+    if (ret >= 0) {
+      // xattrs exist
+      auto iter = bl_xattrs.cbegin();
+      try {
+        decode(xattr_reservations, iter);
+      } catch (ceph::buffer::error& err) {
+        CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: failed to decode xattrs urgent data map");
+        return -EINVAL;
+      } //end - catch
+    }
+    std::tie(std::ignore, result) = xattr_reservations.emplace(std::piecewise_construct,
+          std::forward_as_tuple(urgent_data.last_id),
+          std::forward_as_tuple(res_op.size, ceph::coarse_real_clock::now()));
+    if (!result) {
+      // an old reservation that was never committed or aborted is in the map
+      // caller should try again assuming other IDs are ok
+      CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: reservation id conflict inside xattrs after rollover: %u", urgent_data.last_id);
+      return -EAGAIN;
+    }
+    bl_xattrs.clear();
+    encode(xattr_reservations, bl_xattrs);
+    ret = cls_cxx_setxattr(hctx, CLS_QUEUE_URGENT_DATA_XATTR_NAME, &bl_xattrs);
+    if (ret < 0) {
+      CLS_LOG(1, "ERROR: cls_2pc_queue_reserve: failed to write xattrs with: %d", ret);
+      return ret;
+    }
+    // remove the last reservation from the reservation list
+    // and indicate that spillover happened
+    urgent_data.has_xattrs = true;
+    urgent_data.reservations.erase(last_reservation);
+    head.bl_urgent_data.clear();
+    encode(urgent_data, head.bl_urgent_data);
+  }
+
+  ret = queue_write_head(hctx, head);
+  if (ret < 0) {
+    return ret;
+  }
+  
+  CLS_LOG(20, "INFO: cls_2pc_queue_reserve: remaining size: %lu (bytes)", remaining_size);
+  CLS_LOG(20, "INFO: cls_2pc_queue_reserve: current reservations: %lu (bytes)", urgent_data.reserved_size);
+  CLS_LOG(20, "INFO: cls_2pc_queue_reserve: requested size: %lu (bytes)", res_op.size);
+  CLS_LOG(20, "INFO: cls_2pc_queue_reserve: urgent data size: %lu (bytes)", urgent_data_length);
+
+  cls_2pc_queue_reserve_ret op_ret;
+  op_ret.id = urgent_data.last_id;
+  encode(op_ret, *out);
+
+  return 0;
+}
+
+static int cls_2pc_queue_commit(cls_method_context_t hctx, bufferlist *in, bufferlist *out) {
+  cls_2pc_queue_commit_op commit_op;
+  try {
+    auto in_iter = in->cbegin();
+    decode(commit_op, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_commit: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+  
+  // get head
+  cls_queue_head head;
+  int ret = queue_read_head(hctx, head);
+  if (ret < 0) {
+    return ret;
+  }
+
+  cls_2pc_urgent_data urgent_data;
+  try {
+    auto in_iter = head.bl_urgent_data.cbegin();
+    decode(urgent_data, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_commit: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+  
+  auto it = urgent_data.reservations.find(commit_op.id);
+  cls_2pc_reservations xattr_reservations;
+  bufferlist bl_xattrs;
+  if (it == urgent_data.reservations.end()) {
+    if (!urgent_data.has_xattrs) {
+        CLS_LOG(1, "ERROR: cls_2pc_queue_commit: reservation does not exist: %u", commit_op.id);
+        return -ENOENT;
+    }
+    // try to look for the reservation in xattrs
+    auto ret = cls_cxx_getxattr(hctx, CLS_QUEUE_URGENT_DATA_XATTR_NAME, &bl_xattrs);
+    if (ret < 0) {
+      if (ret == -ENOENT || ret == -ENODATA) {
+        // no xattrs, reservation does not exists
+        CLS_LOG(1, "ERROR: cls_2pc_queue_commit: reservation does not exist: %u", commit_op.id);
+        return -ENOENT;
+      }
+      CLS_LOG(1, "ERROR: cls_2pc_queue_commit: failed to read xattrs with: %d", ret);
+      return ret;
+    }
+    auto iter = bl_xattrs.cbegin();
+    try {
+      decode(xattr_reservations, iter);
+    } catch (ceph::buffer::error& err) {
+      CLS_LOG(1, "ERROR: cls_2pc_queue_commit: failed to decode xattrs urgent data map");
+      return -EINVAL;
+    } //end - catch
+    it = xattr_reservations.find(commit_op.id);
+    if (it == urgent_data.reservations.end()) {
+      CLS_LOG(1, "ERROR: cls_2pc_queue_commit: reservation does not exist: %u", commit_op.id);
+      return -ENOENT;
+    }
+  }
+
+  auto& res = it->second;
+  const auto actual_size = std::accumulate(commit_op.bl_data_vec.begin(), 
+          commit_op.bl_data_vec.end(), 0UL, [] (uint64_t sum, const bufferlist& bl) {
+            return sum + bl.length();
+          });
+   
+  if (res.size < actual_size) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_commit: trying to commit %lu bytes to a %lu bytes reservation", 
+            actual_size,
+            res.size);
+    return -EINVAL;
+  }
+
+  // commit the data to the queue
+  cls_queue_enqueue_op enqueue_op;
+  enqueue_op.bl_data_vec = std::move(commit_op.bl_data_vec);
+  ret = queue_enqueue(hctx, enqueue_op, head);
+  if (ret < 0) {
+    return ret;
+  }
+
+  urgent_data.reserved_size -= res.size;
+
+  if (xattr_reservations.empty()) {
+    // remove the reservation from urgent data
+    urgent_data.reservations.erase(it);
+  } else {
+    // remove the reservation from xattrs
+    xattr_reservations.erase(it);
+    bl_xattrs.clear();
+    encode(xattr_reservations, bl_xattrs);
+    ret = cls_cxx_setxattr(hctx, CLS_QUEUE_URGENT_DATA_XATTR_NAME, &bl_xattrs);
+    if (ret < 0) {
+      CLS_LOG(1, "ERROR: cls_2pc_queue_commit: failed to write xattrs with: %d", ret);
+      return ret;
+    }
+  }
+  
+  CLS_LOG(20, "INFO: cls_2pc_queue_commit: current reservations: %lu (bytes)", urgent_data.reserved_size);
+  CLS_LOG(20, "INFO: cls_2pc_queue_commit: current reservation entries: %lu", 
+          urgent_data.reservations.size() + xattr_reservations.size());
+
+  // write back head
+  head.bl_urgent_data.clear();
+  encode(urgent_data, head.bl_urgent_data);
+  return queue_write_head(hctx, head);
+}
+
+static int cls_2pc_queue_abort(cls_method_context_t hctx, bufferlist *in, bufferlist *out) {
+  cls_2pc_queue_abort_op abort_op;
+  try {
+    auto in_iter = in->cbegin();
+    decode(abort_op, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_abort: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+  
+  // get head
+  cls_queue_head head;
+  int ret = queue_read_head(hctx, head);
+  if (ret < 0) {
+    return ret;
+  }
+
+  cls_2pc_urgent_data urgent_data;
+  try {
+    auto in_iter = head.bl_urgent_data.cbegin();
+    decode(urgent_data, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_abort: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+ 
+  auto it = urgent_data.reservations.find(abort_op.id);
+  uint64_t reservation_size;
+  if (it == urgent_data.reservations.end()) {
+    if (!urgent_data.has_xattrs) {
+      CLS_LOG(20, "INFO: cls_2pc_queue_abort: reservation does not exist: %u", abort_op.id);
+      return 0;
+    }
+    // try to look for the reservation in xattrs
+    bufferlist bl_xattrs;
+    auto ret = cls_cxx_getxattr(hctx, CLS_QUEUE_URGENT_DATA_XATTR_NAME, &bl_xattrs);
+    if (ret < 0) {
+      if (ret == -ENOENT || ret == -ENODATA) {
+        // no xattrs, reservation does not exists
+        CLS_LOG(20, "INFO: cls_2pc_queue_abort: reservation does not exist: %u", abort_op.id);
+        return 0;
+      }
+      CLS_LOG(1, "ERROR: cls_2pc_queue_abort: failed to read xattrs with: %d", ret);
+      return ret;
+    }
+    auto iter = bl_xattrs.cbegin();
+    cls_2pc_reservations xattr_reservations;
+    try {
+      decode(xattr_reservations, iter);
+    } catch (ceph::buffer::error& err) {
+      CLS_LOG(1, "ERROR: cls_2pc_queue_abort: failed to decode xattrs urgent data map");
+      return -EINVAL;
+    } //end - catch
+    it = xattr_reservations.find(abort_op.id);
+    if (it == xattr_reservations.end()) {
+      CLS_LOG(20, "INFO: cls_2pc_queue_abort: reservation does not exist: %u", abort_op.id);
+      return 0;
+    }
+    reservation_size = it->second.size;
+    xattr_reservations.erase(it);
+    bl_xattrs.clear();
+    encode(xattr_reservations, bl_xattrs);
+    ret = cls_cxx_setxattr(hctx, CLS_QUEUE_URGENT_DATA_XATTR_NAME, &bl_xattrs);
+    if (ret < 0) {
+      CLS_LOG(1, "ERROR: cls_2pc_queue_abort: failed to write xattrs with: %d", ret);
+      return ret;
+    }
+  } else {
+    reservation_size = it->second.size;
+    urgent_data.reservations.erase(it);
+  }
+
+  // remove the reservation
+  urgent_data.reserved_size -= reservation_size;
+
+  CLS_LOG(20, "INFO: cls_2pc_queue_abort: current reservations: %lu (bytes)", urgent_data.reserved_size);
+
+  // write back head
+  head.bl_urgent_data.clear();
+  encode(urgent_data, head.bl_urgent_data);
+  return queue_write_head(hctx, head);
+}
+
+static int cls_2pc_queue_list_reservations(cls_method_context_t hctx, bufferlist *in, bufferlist *out) {
+  //get head
+  cls_queue_head head;
+  auto ret = queue_read_head(hctx, head);
+  if (ret < 0) {
+    return ret;
+  }
+
+  cls_2pc_urgent_data urgent_data;
+  try {
+    auto in_iter = head.bl_urgent_data.cbegin();
+    decode(urgent_data, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_list_reservations: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+  
+  CLS_LOG(20, "INFO: cls_2pc_queue_list_reservations: %lu reservation entries found", urgent_data.reservations.size());
+  cls_2pc_queue_reservations_ret op_ret;
+  op_ret.reservations = std::move(urgent_data.reservations);
+  if (urgent_data.has_xattrs) {
+    // try to look for the reservation in xattrs
+    cls_2pc_reservations xattr_reservations;
+    bufferlist bl_xattrs;
+    ret = cls_cxx_getxattr(hctx, CLS_QUEUE_URGENT_DATA_XATTR_NAME, &bl_xattrs);
+    if (ret < 0 && (ret != -ENOENT && ret != -ENODATA)) {
+      CLS_LOG(1, "ERROR: cls_2pc_queue_list_reservations: failed to read xattrs with: %d", ret);
+      return ret;
+    }
+    if (ret >= 0) {
+      auto iter = bl_xattrs.cbegin();
+      try {
+        decode(xattr_reservations, iter);
+      } catch (ceph::buffer::error& err) {
+        CLS_LOG(1, "ERROR: cls_2pc_queue_list_reservations: failed to decode xattrs urgent data map");
+        return -EINVAL;
+      } //end - catch
+      CLS_LOG(20, "INFO: cls_2pc_queue_list_reservations: %lu reservation entries found in xatts", xattr_reservations.size());
+      op_ret.reservations.merge(xattr_reservations);
+    }
+  }
+  encode(op_ret, *out);
+
+  return 0;
+}
+
+static int cls_2pc_queue_expire_reservations(cls_method_context_t hctx, bufferlist *in, bufferlist *out) {
+  cls_2pc_queue_expire_op expire_op;
+  try {
+    auto in_iter = in->cbegin();
+    decode(expire_op, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_expire_reservations: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+
+  //get head
+  cls_queue_head head;
+  auto ret = queue_read_head(hctx, head);
+  if (ret < 0) {
+    return ret;
+  }
+
+  cls_2pc_urgent_data urgent_data;
+  try {
+    auto in_iter = head.bl_urgent_data.cbegin();
+    decode(urgent_data, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_expire_reservations: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+  
+  CLS_LOG(20, "INFO: cls_2pc_queue_expire_reservations: %lu reservation entries found", urgent_data.reservations.size());
+  CLS_LOG(20, "INFO: cls_2pc_queue_expire_reservations: current reservations: %lu (bytes)", urgent_data.reserved_size);
+
+  uint64_t reservation_size = 0U;
+  auto stale_found = false;
+  auto xattr_stale_found = false;
+
+  for (auto it = urgent_data.reservations.begin(); it != urgent_data.reservations.end();) {
+    if (it->second.timestamp < expire_op.stale_time) {
+      CLS_LOG(5, "WARNING: cls_2pc_queue_expire_reservations: stale reservation %u will be removed", it->first);
+      reservation_size += it->second.size;
+      it = urgent_data.reservations.erase(it);
+      stale_found = true;
+    } else {
+      ++it;
+    }
+  }
+
+  if (urgent_data.has_xattrs) {
+    // try to look for the reservation in xattrs
+    cls_2pc_reservations xattr_reservations;
+    bufferlist bl_xattrs;
+    ret = cls_cxx_getxattr(hctx, CLS_QUEUE_URGENT_DATA_XATTR_NAME, &bl_xattrs);
+    if (ret < 0 && (ret != -ENOENT && ret != -ENODATA)) {
+      CLS_LOG(1, "ERROR: cls_2pc_queue_expire_reservations: failed to read xattrs with: %d", ret);
+      return ret;
+    }
+    if (ret >= 0) {
+      auto iter = bl_xattrs.cbegin();
+      try {
+        decode(xattr_reservations, iter);
+      } catch (ceph::buffer::error& err) {
+        CLS_LOG(1, "ERROR: cls_2pc_queue_expire_reservations: failed to decode xattrs urgent data map");
+        return -EINVAL;
+      } //end - catch
+      CLS_LOG(20, "INFO: cls_2pc_queue_expire_reservations: %lu reservation entries found in xatts", xattr_reservations.size());
+      for (auto it = xattr_reservations.begin(); it != xattr_reservations.end();) {
+        if (it->second.timestamp < expire_op.stale_time) {
+          CLS_LOG(5, "WARNING: cls_2pc_queue_expire_reservations: stale reservation %u will be removed", it->first);
+          reservation_size += it->second.size;
+          it = xattr_reservations.erase(it);
+          xattr_stale_found = true;
+        } else {
+          ++it;
+        }
+      }
+      if (xattr_stale_found) {
+        // write xattr back without stale reservations
+        bl_xattrs.clear();
+        encode(xattr_reservations, bl_xattrs);
+        ret = cls_cxx_setxattr(hctx, CLS_QUEUE_URGENT_DATA_XATTR_NAME, &bl_xattrs);
+        if (ret < 0) {
+          CLS_LOG(1, "ERROR: cls_2pc_queue_expire_reservations: failed to write xattrs with: %d", ret);
+          return ret;
+        }
+      }
+    }
+  }
+
+  if (stale_found || xattr_stale_found) { 
+    urgent_data.reserved_size -= reservation_size;
+    CLS_LOG(20, "INFO: cls_2pc_queue_expire_reservations: reservations after cleanup: %lu (bytes)", urgent_data.reserved_size);
+    // write back head without stale reservations
+    head.bl_urgent_data.clear();
+    encode(urgent_data, head.bl_urgent_data);
+    return queue_write_head(hctx, head);
+  }
+
+  return 0;
+}
+
+static int cls_2pc_queue_list_entries(cls_method_context_t hctx, bufferlist *in, bufferlist *out)
+{
+  auto in_iter = in->cbegin();
+  cls_queue_list_op op;
+  try {
+    decode(op, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_list_entries: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+
+  cls_queue_head head;
+  auto ret = queue_read_head(hctx, head);
+  if (ret < 0) {
+    return ret;
+  }
+
+  cls_queue_list_ret op_ret;
+  ret = queue_list_entries(hctx, op, op_ret, head);
+  if (ret < 0) {
+    return ret;
+  }
+
+  encode(op_ret, *out);
+  return 0;
+}
+
+static int cls_2pc_queue_remove_entries(cls_method_context_t hctx, bufferlist *in, bufferlist *out)
+{
+  auto in_iter = in->cbegin();
+  cls_queue_remove_op op;
+  try {
+    decode(op, in_iter);
+  } catch (ceph::buffer::error& err) {
+    CLS_LOG(1, "ERROR: cls_2pc_queue_remove_entries: failed to decode entry: %s", err.what());
+    return -EINVAL;
+  }
+
+  cls_queue_head head;
+  auto ret = queue_read_head(hctx, head);
+  if (ret < 0) {
+    return ret;
+  }
+  ret = queue_remove_entries(hctx, op, head);
+  if (ret < 0) {
+    return ret;
+  }
+  return queue_write_head(hctx, head);
+}
+
+CLS_INIT(2pc_queue)
+{
+  CLS_LOG(1, "Loaded 2pc queue class!");
+
+  cls_handle_t h_class;
+  cls_method_handle_t h_2pc_queue_init;
+  cls_method_handle_t h_2pc_queue_get_capacity;
+  cls_method_handle_t h_2pc_queue_reserve;
+  cls_method_handle_t h_2pc_queue_commit;
+  cls_method_handle_t h_2pc_queue_abort;
+  cls_method_handle_t h_2pc_queue_list_reservations;
+  cls_method_handle_t h_2pc_queue_list_entries;
+  cls_method_handle_t h_2pc_queue_remove_entries;
+  cls_method_handle_t h_2pc_queue_expire_reservations;
+
+  cls_register(TPC_QUEUE_CLASS, &h_class);
+
+  cls_register_cxx_method(h_class, TPC_QUEUE_INIT, CLS_METHOD_RD | CLS_METHOD_WR, cls_2pc_queue_init, &h_2pc_queue_init);
+  cls_register_cxx_method(h_class, TPC_QUEUE_GET_CAPACITY, CLS_METHOD_RD, cls_2pc_queue_get_capacity, &h_2pc_queue_get_capacity);
+  cls_register_cxx_method(h_class, TPC_QUEUE_RESERVE, CLS_METHOD_RD | CLS_METHOD_WR, cls_2pc_queue_reserve, &h_2pc_queue_reserve);
+  cls_register_cxx_method(h_class, TPC_QUEUE_COMMIT, CLS_METHOD_RD | CLS_METHOD_WR, cls_2pc_queue_commit, &h_2pc_queue_commit);
+  cls_register_cxx_method(h_class, TPC_QUEUE_ABORT, CLS_METHOD_RD | CLS_METHOD_WR, cls_2pc_queue_abort, &h_2pc_queue_abort);
+  cls_register_cxx_method(h_class, TPC_QUEUE_LIST_RESERVATIONS, CLS_METHOD_RD, cls_2pc_queue_list_reservations, &h_2pc_queue_list_reservations);
+  cls_register_cxx_method(h_class, TPC_QUEUE_LIST_ENTRIES, CLS_METHOD_RD, cls_2pc_queue_list_entries, &h_2pc_queue_list_entries);
+  cls_register_cxx_method(h_class, TPC_QUEUE_REMOVE_ENTRIES, CLS_METHOD_RD | CLS_METHOD_WR, cls_2pc_queue_remove_entries, &h_2pc_queue_remove_entries);
+  cls_register_cxx_method(h_class, TPC_QUEUE_EXPIRE_RESERVATIONS, CLS_METHOD_RD | CLS_METHOD_WR, cls_2pc_queue_expire_reservations, &h_2pc_queue_expire_reservations);
+
+  return;
+}
+