initial code repo
[stor4nfv.git] / src / ceph / src / common / obj_bencher.cc
diff --git a/src/ceph/src/common/obj_bencher.cc b/src/ceph/src/common/obj_bencher.cc
new file mode 100644 (file)
index 0000000..4eaeba3
--- /dev/null
@@ -0,0 +1,1467 @@
+// -*- 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) 2009 Sage Weil <sage@newdream.net>
+ *
+ * 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.
+ *
+ * Series of functions to test your rados installation. Notice
+ * that this code is not terribly robust -- for instance, if you
+ * try and bench on a pool you don't have permission to access
+ * it will just loop forever.
+ */
+#include "include/compat.h"
+#include <pthread.h>
+#include "common/Cond.h"
+#include "obj_bencher.h"
+
+const std::string BENCH_LASTRUN_METADATA = "benchmark_last_metadata";
+const std::string BENCH_PREFIX = "benchmark_data";
+static char cached_hostname[30] = {0};
+int cached_pid = 0;
+
+static std::string generate_object_prefix_nopid() {
+  if (cached_hostname[0] == 0) {
+    gethostname(cached_hostname, sizeof(cached_hostname)-1);
+    cached_hostname[sizeof(cached_hostname)-1] = 0;
+  }
+
+  std::ostringstream oss;
+  oss << BENCH_PREFIX << "_" << cached_hostname;
+  return oss.str();
+}
+
+static std::string generate_object_prefix(int pid = 0) {
+  if (pid)
+    cached_pid = pid;
+  else if (!cached_pid)
+    cached_pid = getpid();
+
+  std::ostringstream oss;
+  oss << generate_object_prefix_nopid() << "_" << cached_pid;
+  return oss.str();
+}
+
+static std::string generate_object_name(int objnum, int pid = 0)
+{
+  std::ostringstream oss;
+  oss << generate_object_prefix(pid) << "_object" << objnum;
+  return oss.str();
+}
+
+static void sanitize_object_contents (bench_data *data, size_t length) {
+  memset(data->object_contents, 'z', length);
+}
+
+ostream& ObjBencher::out(ostream& os, utime_t& t)
+{
+  if (show_time)
+    return t.localtime(os) << " ";
+  else
+    return os;
+}
+
+ostream& ObjBencher::out(ostream& os)
+{
+  utime_t cur_time = ceph_clock_now();
+  return out(os, cur_time);
+}
+
+void *ObjBencher::status_printer(void *_bencher) {
+  ObjBencher *bencher = static_cast<ObjBencher *>(_bencher);
+  bench_data& data = bencher->data;
+  Formatter *formatter = bencher->formatter;
+  ostream *outstream = bencher->outstream;
+  Cond cond;
+  int i = 0;
+  int previous_writes = 0;
+  int cycleSinceChange = 0;
+  double bandwidth;
+  int iops;
+  utime_t ONE_SECOND;
+  ONE_SECOND.set_from_double(1.0);
+  bencher->lock.Lock();
+  if (formatter)
+    formatter->open_array_section("datas");
+  while(!data.done) {
+    utime_t cur_time = ceph_clock_now();
+
+    if (i % 20 == 0 && !formatter) {
+      if (i > 0)
+        cur_time.localtime(cout) << " min lat: " << data.min_latency
+          << " max lat: " << data.max_latency
+          << " avg lat: " << data.avg_latency << std::endl;
+      //I'm naughty and don't reset the fill
+      bencher->out(cout, cur_time) << setfill(' ')
+          << setw(5) << "sec"
+          << setw(8) << "Cur ops"
+          << setw(10) << "started"
+          << setw(10) << "finished"
+          << setw(10) << "avg MB/s"
+          << setw(10) << "cur MB/s"
+          << setw(12) << "last lat(s)"
+          << setw(12) << "avg lat(s)" << std::endl;
+    }
+    if (cycleSinceChange)
+      bandwidth = (double)(data.finished - previous_writes)
+        * (data.op_size)
+        / (1024*1024)
+        / cycleSinceChange;
+    else
+      bandwidth = -1;
+
+    if (!std::isnan(bandwidth) && bandwidth > -1) {
+      if (bandwidth > data.idata.max_bandwidth)
+        data.idata.max_bandwidth = bandwidth;
+      if (bandwidth < data.idata.min_bandwidth)
+        data.idata.min_bandwidth = bandwidth;
+
+      data.history.bandwidth.push_back(bandwidth);
+    }
+
+    if (cycleSinceChange)
+      iops = (double)(data.finished - previous_writes)
+        / cycleSinceChange;
+    else
+      iops = -1;
+
+    if (!std::isnan(iops) && iops > -1) {
+      if (iops > data.idata.max_iops)
+        data.idata.max_iops = iops;
+      if (iops < data.idata.min_iops)
+        data.idata.min_iops = iops;
+
+      data.history.iops.push_back(iops);
+    }
+    
+    if (formatter)
+      formatter->open_object_section("data");
+
+    double avg_bandwidth = (double) (data.op_size) * (data.finished)
+      / (double)(cur_time - data.start_time) / (1024*1024);
+    if (previous_writes != data.finished) {
+      previous_writes = data.finished;
+      cycleSinceChange = 0;
+      if (!formatter) {
+        bencher->out(cout, cur_time)
+         << setfill(' ')
+          << setw(5) << i
+         << ' ' << setw(7) << data.in_flight
+          << ' ' << setw(9) << data.started
+          << ' ' << setw(9) << data.finished
+          << ' ' << setw(9) << avg_bandwidth
+          << ' ' << setw(9) << bandwidth
+          << ' ' << setw(11) << (double)data.cur_latency
+          << ' ' << setw(11) << data.avg_latency << std::endl;
+      } else {
+        formatter->dump_format("sec", "%d", i);
+        formatter->dump_format("cur_ops", "%d", data.in_flight);
+        formatter->dump_format("started", "%d", data.started);
+        formatter->dump_format("finished", "%d", data.finished);
+        formatter->dump_format("avg_bw", "%f", avg_bandwidth);
+        formatter->dump_format("cur_bw", "%f", bandwidth);
+        formatter->dump_format("last_lat", "%f", (double)data.cur_latency);
+        formatter->dump_format("avg_lat", "%f", data.avg_latency);
+      }
+    }
+    else {
+      if (!formatter) {
+        bencher->out(cout, cur_time)
+         << setfill(' ')
+          << setw(5) << i
+         << ' ' << setw(7) << data.in_flight
+          << ' ' << setw(9) << data.started
+          << ' ' << setw(9) << data.finished
+          << ' ' << setw(9) << avg_bandwidth
+         << ' ' << setw(9) << '0'
+          << ' ' << setw(11) << '-'
+          << ' '<< setw(11) << data.avg_latency << std::endl;
+      } else {
+        formatter->dump_format("sec", "%d", i);
+        formatter->dump_format("cur_ops", "%d", data.in_flight);
+        formatter->dump_format("started", "%d", data.started);
+        formatter->dump_format("finished", "%d", data.finished);
+        formatter->dump_format("avg_bw", "%f", avg_bandwidth);
+        formatter->dump_format("cur_bw", "%f", 0);
+        formatter->dump_format("last_lat", "%f", 0);
+        formatter->dump_format("avg_lat", "%f", data.avg_latency);
+      }
+    }
+    if (formatter) {
+      formatter->close_section(); // data
+      formatter->flush(*outstream);
+    }
+    ++i;
+    ++cycleSinceChange;
+    cond.WaitInterval(bencher->lock, ONE_SECOND);
+  }
+  if (formatter)
+    formatter->close_section(); //datas
+  bencher->lock.Unlock();
+  return NULL;
+}
+
+int ObjBencher::aio_bench(
+  int operation, int secondsToRun,
+  int concurrentios,
+  uint64_t op_size, uint64_t object_size,
+  unsigned max_objects,
+  bool cleanup, bool hints,
+  const std::string& run_name, bool no_verify) {
+
+  if (concurrentios <= 0)
+    return -EINVAL;
+
+  int num_objects = 0;
+  int r = 0;
+  int prevPid = 0;
+  utime_t runtime;
+
+  // default metadata object is used if user does not specify one
+  const std::string run_name_meta = (run_name.empty() ? BENCH_LASTRUN_METADATA : run_name);
+
+  //get data from previous write run, if available
+  if (operation != OP_WRITE) {
+    uint64_t prev_op_size, prev_object_size;
+    r = fetch_bench_metadata(run_name_meta, &prev_op_size, &prev_object_size,
+                            &num_objects, &prevPid);
+    if (r < 0) {
+      if (r == -ENOENT)
+        cerr << "Must write data before running a read benchmark!" << std::endl;
+      return r;
+    }
+    object_size = prev_object_size;   
+    op_size = prev_op_size;           
+  }
+
+  char* contentsChars = new char[op_size];
+  lock.Lock();
+  data.done = false;
+  data.hints = hints;
+  data.object_size = object_size;
+  data.op_size = op_size;
+  data.in_flight = 0;
+  data.started = 0;
+  data.finished = 0;
+  data.min_latency = 9999.0; // this better be higher than initial latency!
+  data.max_latency = 0;
+  data.avg_latency = 0;
+  data.object_contents = contentsChars;
+  lock.Unlock();
+
+  //fill in contentsChars deterministically so we can check returns
+  sanitize_object_contents(&data, data.op_size);
+
+  if (formatter)
+    formatter->open_object_section("bench");
+
+  if (OP_WRITE == operation) {
+    r = write_bench(secondsToRun, concurrentios, run_name_meta, max_objects);
+    if (r != 0) goto out;
+  }
+  else if (OP_SEQ_READ == operation) {
+    r = seq_read_bench(secondsToRun, num_objects, concurrentios, prevPid, no_verify);
+    if (r != 0) goto out;
+  }
+  else if (OP_RAND_READ == operation) {
+    r = rand_read_bench(secondsToRun, num_objects, concurrentios, prevPid, no_verify);
+    if (r != 0) goto out;
+  }
+
+  if (OP_WRITE == operation && cleanup) {
+    r = fetch_bench_metadata(run_name_meta, &op_size, &object_size,
+                            &num_objects, &prevPid);
+    if (r < 0) {
+      if (r == -ENOENT)
+        cerr << "Should never happen: bench metadata missing for current run!" << std::endl;
+      goto out;
+    }
+
+    data.start_time = ceph_clock_now();
+    out(cout) << "Cleaning up (deleting benchmark objects)" << std::endl;
+
+    r = clean_up(num_objects, prevPid, concurrentios);
+    if (r != 0) goto out;
+
+    runtime = ceph_clock_now() - data.start_time;
+    out(cout) << "Clean up completed and total clean up time :" << runtime << std::endl;
+
+    // lastrun file
+    r = sync_remove(run_name_meta);
+    if (r != 0) goto out;
+  }
+
+ out:
+  if (formatter) {
+    formatter->close_section(); // bench
+    formatter->flush(*outstream);
+    *outstream << std::endl;
+  }
+  delete[] contentsChars;
+  return r;
+}
+
+struct lock_cond {
+  explicit lock_cond(Mutex *_lock) : lock(_lock) {}
+  Mutex *lock;
+  Cond cond;
+};
+
+void _aio_cb(void *cb, void *arg) {
+  struct lock_cond *lc = (struct lock_cond *)arg;
+  lc->lock->Lock();
+  lc->cond.Signal();
+  lc->lock->Unlock();
+}
+
+template<class T>
+static T vec_stddev(vector<T>& v)
+{
+  T mean = 0;
+
+  if (v.size() < 2)
+    return 0;
+
+  typename vector<T>::iterator iter;
+  for (iter = v.begin(); iter != v.end(); ++iter) {
+    mean += *iter;
+  }
+
+  mean /= v.size();
+
+  T stddev = 0;
+  for (iter = v.begin(); iter != v.end(); ++iter) {
+    T dev = *iter - mean;
+    dev *= dev;
+    stddev += dev;
+  }
+  stddev /= (v.size() - 1);
+  return sqrt(stddev);
+}
+
+int ObjBencher::fetch_bench_metadata(const std::string& metadata_file,
+                                    uint64_t *op_size, uint64_t* object_size,
+                                    int* num_objects, int* prevPid) {
+  int r = 0;
+  bufferlist object_data;
+
+  r = sync_read(metadata_file, object_data,
+               sizeof(int) * 2 + sizeof(size_t) * 2);
+  if (r <= 0) {
+    // treat an empty file as a file that does not exist
+    if (r == 0) {
+      r = -ENOENT;
+    }
+    return r;
+  }
+  bufferlist::iterator p = object_data.begin();
+  ::decode(*object_size, p);
+  ::decode(*num_objects, p);
+  ::decode(*prevPid, p);
+  if (!p.end()) {
+    ::decode(*op_size, p);
+  } else {
+    *op_size = *object_size;
+  }
+
+  return 0;
+}
+
+int ObjBencher::write_bench(int secondsToRun,
+                           int concurrentios, const string& run_name_meta,
+                           unsigned max_objects) {
+  if (concurrentios <= 0) 
+    return -EINVAL;
+  
+  if (!formatter) {
+    out(cout) << "Maintaining " << concurrentios << " concurrent writes of "
+             << data.op_size << " bytes to objects of size "
+             << data.object_size << " for up to "
+             << secondsToRun << " seconds or "
+             << max_objects << " objects"
+             << std::endl;
+  } else {
+    formatter->dump_format("concurrent_ios", "%d", concurrentios);
+    formatter->dump_format("object_size", "%d", data.object_size);
+    formatter->dump_format("op_size", "%d", data.op_size);
+    formatter->dump_format("seconds_to_run", "%d", secondsToRun);
+    formatter->dump_format("max_objects", "%d", max_objects);
+  }
+  bufferlist* newContents = 0;
+
+  std::string prefix = generate_object_prefix();
+  if (!formatter)
+    out(cout) << "Object prefix: " << prefix << std::endl;
+  else
+    formatter->dump_string("object_prefix", prefix);
+
+  std::vector<string> name(concurrentios);
+  std::string newName;
+  bufferlist* contents[concurrentios];
+  double total_latency = 0;
+  std::vector<utime_t> start_times(concurrentios);
+  utime_t stopTime;
+  int r = 0;
+  bufferlist b_write;
+  lock_cond lc(&lock);
+  utime_t runtime;
+  utime_t timePassed;
+
+  unsigned writes_per_object = 1;
+  if (data.op_size)
+    writes_per_object = data.object_size / data.op_size;
+
+  r = completions_init(concurrentios);
+
+  //set up writes so I can start them together
+  for (int i = 0; i<concurrentios; ++i) {
+    name[i] = generate_object_name(i / writes_per_object);
+    contents[i] = new bufferlist();
+    snprintf(data.object_contents, data.op_size, "I'm the %16dth op!", i);
+    contents[i]->append(data.object_contents, data.op_size);
+  }
+
+  pthread_t print_thread;
+
+  pthread_create(&print_thread, NULL, ObjBencher::status_printer, (void *)this);
+  ceph_pthread_setname(print_thread, "write_stat");
+  lock.Lock();
+  data.finished = 0;
+  data.start_time = ceph_clock_now();
+  lock.Unlock();
+  for (int i = 0; i<concurrentios; ++i) {
+    start_times[i] = ceph_clock_now();
+    r = create_completion(i, _aio_cb, (void *)&lc);
+    if (r < 0)
+      goto ERR;
+    r = aio_write(name[i], i, *contents[i], data.op_size,
+                 data.op_size * (i % writes_per_object));
+    if (r < 0) { //naughty, doesn't clean up heap
+      goto ERR;
+    }
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    lock.Unlock();
+  }
+
+  //keep on adding new writes as old ones complete until we've passed minimum time
+  int slot;
+  int num_objects;
+
+  //don't need locking for reads because other thread doesn't write
+
+  runtime.set_from_double(secondsToRun);
+  stopTime = data.start_time + runtime;
+  slot = 0;
+  lock.Lock();
+  while (!secondsToRun || ceph_clock_now() < stopTime) {
+    bool found = false;
+    while (1) {
+      int old_slot = slot;
+      do {
+        if (completion_is_done(slot)) {
+            found = true;
+            break;
+        }
+        slot++;
+        if (slot == concurrentios) {
+          slot = 0;
+        }
+      } while (slot != old_slot);
+      if (found)
+        break;
+      lc.cond.Wait(lock);
+    }
+    lock.Unlock();
+    //create new contents and name on the heap, and fill them
+    newName = generate_object_name(data.started / writes_per_object);
+    newContents = contents[slot];
+    snprintf(newContents->c_str(), data.op_size, "I'm the %16dth op!", data.started);
+    // we wrote to buffer, going around internal crc cache, so invalidate it now.
+    newContents->invalidate_crc();
+
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r != 0) {
+      lock.Unlock();
+      goto ERR;
+    }
+    data.cur_latency = ceph_clock_now() - start_times[slot];
+    data.history.latency.push_back(data.cur_latency);
+    total_latency += data.cur_latency;
+    if( data.cur_latency > data.max_latency) data.max_latency = data.cur_latency;
+    if (data.cur_latency < data.min_latency) data.min_latency = data.cur_latency;
+    ++data.finished;
+    data.avg_latency = total_latency / data.finished;
+    --data.in_flight;
+    lock.Unlock();
+    release_completion(slot);
+    timePassed = ceph_clock_now() - data.start_time;
+
+    //write new stuff to backend
+    start_times[slot] = ceph_clock_now();
+    r = create_completion(slot, _aio_cb, &lc);
+    if (r < 0)
+      goto ERR;
+    r = aio_write(newName, slot, *newContents, data.op_size,
+                 data.op_size * (data.started % writes_per_object));
+    if (r < 0) {//naughty; doesn't clean up heap space.
+      goto ERR;
+    }
+    name[slot] = newName;
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    if (max_objects &&
+       data.started >= (int)((data.object_size * max_objects + data.op_size - 1) /
+                            data.op_size))
+      break;
+  }
+  lock.Unlock();
+
+  while (data.finished < data.started) {
+    slot = data.finished % concurrentios;
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r != 0) {
+      lock.Unlock();
+      goto ERR;
+    }
+    data.cur_latency = ceph_clock_now() - start_times[slot];
+    data.history.latency.push_back(data.cur_latency);
+    total_latency += data.cur_latency;
+    if (data.cur_latency > data.max_latency) data.max_latency = data.cur_latency;
+    if (data.cur_latency < data.min_latency) data.min_latency = data.cur_latency;
+    ++data.finished;
+    data.avg_latency = total_latency / data.finished;
+    --data.in_flight;
+    lock.Unlock();
+    release_completion(slot);
+    delete contents[slot];
+    contents[slot] = 0;
+  }
+
+  timePassed = ceph_clock_now() - data.start_time;
+  lock.Lock();
+  data.done = true;
+  lock.Unlock();
+
+  pthread_join(print_thread, NULL);
+
+  double bandwidth;
+  bandwidth = ((double)data.finished)*((double)data.op_size)/(double)timePassed;
+  bandwidth = bandwidth/(1024*1024); // we want it in MB/sec
+
+  if (!formatter) {
+    out(cout) << "Total time run:         " << timePassed << std::endl
+       << "Total writes made:      " << data.finished << std::endl
+       << "Write size:             " << data.op_size << std::endl
+       << "Object size:            " << data.object_size << std::endl      
+       << "Bandwidth (MB/sec):     " << setprecision(6) << bandwidth << std::endl
+       << "Stddev Bandwidth:       " << vec_stddev(data.history.bandwidth) << std::endl
+       << "Max bandwidth (MB/sec): " << data.idata.max_bandwidth << std::endl
+       << "Min bandwidth (MB/sec): " << data.idata.min_bandwidth << std::endl
+       << "Average IOPS:           " << (int)(data.finished/timePassed) << std::endl
+       << "Stddev IOPS:            " << vec_stddev(data.history.iops) << std::endl
+       << "Max IOPS:               " << data.idata.max_iops << std::endl
+       << "Min IOPS:               " << data.idata.min_iops << std::endl
+       << "Average Latency(s):     " << data.avg_latency << std::endl
+       << "Stddev Latency(s):      " << vec_stddev(data.history.latency) << std::endl
+       << "Max latency(s):         " << data.max_latency << std::endl
+       << "Min latency(s):         " << data.min_latency << std::endl;
+  } else {
+    formatter->dump_format("total_time_run", "%f", (double)timePassed);
+    formatter->dump_format("total_writes_made", "%d", data.finished);
+    formatter->dump_format("write_size", "%d", data.op_size);
+    formatter->dump_format("object_size", "%d", data.object_size);
+    formatter->dump_format("bandwidth", "%f", bandwidth);
+    formatter->dump_format("stddev_bandwidth", "%f", vec_stddev(data.history.bandwidth));
+    formatter->dump_format("max_bandwidth", "%f", data.idata.max_bandwidth);
+    formatter->dump_format("min_bandwidth", "%f", data.idata.min_bandwidth);
+    formatter->dump_format("average_iops", "%d", (int)(data.finished/timePassed));
+    formatter->dump_format("stddev_iops", "%d", vec_stddev(data.history.iops));
+    formatter->dump_format("max_iops", "%d", data.idata.max_iops);
+    formatter->dump_format("min_iops", "%d", data.idata.min_iops);
+    formatter->dump_format("average_latency", "%f", data.avg_latency);
+    formatter->dump_format("stddev_latency", "%f", vec_stddev(data.history.latency));
+    formatter->dump_format("max_latency:", "%f", data.max_latency);
+    formatter->dump_format("min_latency", "%f", data.min_latency);
+  }
+  //write object size/number data for read benchmarks
+  ::encode(data.object_size, b_write);
+  num_objects = (data.finished + writes_per_object - 1) / writes_per_object;
+  ::encode(num_objects, b_write);
+  ::encode(getpid(), b_write);
+  ::encode(data.op_size, b_write);
+
+  // persist meta-data for further cleanup or read
+  sync_write(run_name_meta, b_write, sizeof(int)*3);
+
+  completions_done();
+  for (int i = 0; i < concurrentios; i++)
+      if (contents[i])
+          delete contents[i];
+
+  return 0;
+
+ ERR:
+  lock.Lock();
+  data.done = 1;
+  lock.Unlock();
+  pthread_join(print_thread, NULL);
+  for (int i = 0; i < concurrentios; i++)
+      if (contents[i])
+          delete contents[i];
+  return r;
+}
+
+int ObjBencher::seq_read_bench(int seconds_to_run, int num_objects, int concurrentios, int pid, bool no_verify) {
+  lock_cond lc(&lock);
+
+  if (concurrentios <= 0) 
+    return -EINVAL;
+
+  std::vector<string> name(concurrentios);
+  std::string newName;
+  bufferlist* contents[concurrentios];
+  int index[concurrentios];
+  int errors = 0;
+  utime_t start_time;
+  std::vector<utime_t> start_times(concurrentios);
+  utime_t time_to_run;
+  time_to_run.set_from_double(seconds_to_run);
+  double total_latency = 0;
+  int r = 0;
+  utime_t runtime;
+  sanitize_object_contents(&data, data.op_size); //clean it up once; subsequent
+  //changes will be safe because string length should remain the same
+
+  unsigned writes_per_object = 1;
+  if (data.op_size)
+    writes_per_object = data.object_size / data.op_size;
+
+  r = completions_init(concurrentios);
+  if (r < 0)
+    return r;
+
+  //set up initial reads
+  for (int i = 0; i < concurrentios; ++i) {
+    name[i] = generate_object_name(i / writes_per_object, pid);
+    contents[i] = new bufferlist();
+  }
+
+  lock.Lock();
+  data.finished = 0;
+  data.start_time = ceph_clock_now();
+  lock.Unlock();
+
+  pthread_t print_thread;
+  pthread_create(&print_thread, NULL, status_printer, (void *)this);
+  ceph_pthread_setname(print_thread, "seq_read_stat");
+
+  utime_t finish_time = data.start_time + time_to_run;
+  //start initial reads
+  for (int i = 0; i < concurrentios; ++i) {
+    index[i] = i;
+    start_times[i] = ceph_clock_now();
+    create_completion(i, _aio_cb, (void *)&lc);
+    r = aio_read(name[i], i, contents[i], data.op_size,
+                data.op_size * (i % writes_per_object));
+    if (r < 0) { //naughty, doesn't clean up heap -- oh, or handle the print thread!
+      cerr << "r = " << r << std::endl;
+      goto ERR;
+    }
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    lock.Unlock();
+  }
+
+  //keep on adding new reads as old ones complete
+  int slot;
+  bufferlist *cur_contents;
+
+  slot = 0;
+  while ((!seconds_to_run || ceph_clock_now() < finish_time) &&
+        num_objects > data.started) {
+    lock.Lock();
+    int old_slot = slot;
+    bool found = false;
+    while (1) {
+      do {
+        if (completion_is_done(slot)) {
+          found = true;
+          break;
+        }
+        slot++;
+        if (slot == concurrentios) {
+          slot = 0;
+        }
+      } while (slot != old_slot);
+      if (found) {
+        break;
+      }
+      lc.cond.Wait(lock);
+    }
+
+    // calculate latency here, so memcmp doesn't inflate it
+    data.cur_latency = ceph_clock_now() - start_times[slot];
+
+    cur_contents = contents[slot];
+    int current_index = index[slot];
+    
+    // invalidate internal crc cache
+    cur_contents->invalidate_crc();
+  
+    if (!no_verify) {
+      snprintf(data.object_contents, data.op_size, "I'm the %16dth op!", current_index);
+      if ( (cur_contents->length() != data.op_size) || 
+           (memcmp(data.object_contents, cur_contents->c_str(), data.op_size) != 0) ) {
+        cerr << name[slot] << " is not correct!" << std::endl;
+        ++errors;
+      }
+    }
+
+    newName = generate_object_name(data.started / writes_per_object, pid);
+    index[slot] = data.started;
+    lock.Unlock();
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r < 0) {
+      cerr << "read got " << r << std::endl;
+      lock.Unlock();
+      goto ERR;
+    }
+    total_latency += data.cur_latency;
+    if (data.cur_latency > data.max_latency) data.max_latency = data.cur_latency;
+    if (data.cur_latency < data.min_latency) data.min_latency = data.cur_latency;
+    ++data.finished;
+    data.avg_latency = total_latency / data.finished;
+    --data.in_flight;
+    lock.Unlock();
+    release_completion(slot);
+
+    //start new read and check data if requested
+    start_times[slot] = ceph_clock_now();
+    create_completion(slot, _aio_cb, (void *)&lc);
+    r = aio_read(newName, slot, contents[slot], data.op_size,
+                data.op_size * (data.started % writes_per_object));
+    if (r < 0) {
+      goto ERR;
+    }
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    lock.Unlock();
+    name[slot] = newName;
+  }
+
+  //wait for final reads to complete
+  while (data.finished < data.started) {
+    slot = data.finished % concurrentios;
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r < 0) {
+      cerr << "read got " << r << std::endl;
+      lock.Unlock();
+      goto ERR;
+    }
+    data.cur_latency = ceph_clock_now() - start_times[slot];
+    total_latency += data.cur_latency;
+    if (data.cur_latency > data.max_latency) data.max_latency = data.cur_latency;
+    if (data.cur_latency < data.min_latency) data.min_latency = data.cur_latency;
+    ++data.finished;
+    data.avg_latency = total_latency / data.finished;
+    --data.in_flight;
+    release_completion(slot);
+    if (!no_verify) {
+      snprintf(data.object_contents, data.op_size, "I'm the %16dth op!", index[slot]);
+      lock.Unlock();
+      if ((contents[slot]->length() != data.op_size) || 
+         (memcmp(data.object_contents, contents[slot]->c_str(), data.op_size) != 0)) {
+        cerr << name[slot] << " is not correct!" << std::endl;
+        ++errors;
+      }
+    } else {
+        lock.Unlock();
+    }
+    delete contents[slot];
+  }
+
+  runtime = ceph_clock_now() - data.start_time;
+  lock.Lock();
+  data.done = true;
+  lock.Unlock();
+
+  pthread_join(print_thread, NULL);
+
+  double bandwidth;
+  bandwidth = ((double)data.finished)*((double)data.op_size)/(double)runtime;
+  bandwidth = bandwidth/(1024*1024); // we want it in MB/sec
+
+  if (!formatter) {
+    out(cout) << "Total time run:       " << runtime << std::endl
+       << "Total reads made:     " << data.finished << std::endl
+       << "Read size:            " << data.op_size << std::endl
+       << "Object size:          " << data.object_size << std::endl
+       << "Bandwidth (MB/sec):   " << setprecision(6) << bandwidth << std::endl
+       << "Average IOPS:         " << (int)(data.finished/runtime) << std::endl
+       << "Stddev IOPS:          " << vec_stddev(data.history.iops) << std::endl
+       << "Max IOPS:             " << data.idata.max_iops << std::endl
+       << "Min IOPS:             " << data.idata.min_iops << std::endl
+       << "Average Latency(s):   " << data.avg_latency << std::endl
+       << "Max latency(s):       " << data.max_latency << std::endl
+       << "Min latency(s):       " << data.min_latency << std::endl;
+  } else {
+    formatter->dump_format("total_time_run", "%f", (double)runtime);
+    formatter->dump_format("total_reads_made", "%d", data.finished);
+    formatter->dump_format("read_size", "%d", data.op_size);
+    formatter->dump_format("object_size", "%d", data.object_size);
+    formatter->dump_format("bandwidth", "%f", bandwidth);
+    formatter->dump_format("average_iops", "%d", (int)(data.finished/runtime));
+    formatter->dump_format("stddev_iops", "%d", vec_stddev(data.history.iops));
+    formatter->dump_format("max_iops", "%d", data.idata.max_iops);
+    formatter->dump_format("min_iops", "%d", data.idata.min_iops);
+    formatter->dump_format("average_latency", "%f", data.avg_latency);
+    formatter->dump_format("max_latency", "%f", data.max_latency);
+    formatter->dump_format("min_latency", "%f", data.min_latency);
+  }
+
+  completions_done();
+
+  return (errors > 0 ? -EIO : 0);
+
+ ERR:
+  lock.Lock();
+  data.done = 1;
+  lock.Unlock();
+  pthread_join(print_thread, NULL);
+  return r;
+}
+
+int ObjBencher::rand_read_bench(int seconds_to_run, int num_objects, int concurrentios, int pid, bool no_verify)
+{
+  lock_cond lc(&lock);
+
+  if (concurrentios <= 0)
+    return -EINVAL;
+
+  std::vector<string> name(concurrentios);
+  std::string newName;
+  bufferlist* contents[concurrentios];
+  int index[concurrentios];
+  int errors = 0;
+  utime_t start_time;
+  std::vector<utime_t> start_times(concurrentios);
+  utime_t time_to_run;
+  time_to_run.set_from_double(seconds_to_run);
+  double total_latency = 0;
+  int r = 0;
+  utime_t runtime;
+  sanitize_object_contents(&data, data.op_size); //clean it up once; subsequent
+  //changes will be safe because string length should remain the same
+
+  unsigned writes_per_object = 1;
+  if (data.op_size)
+    writes_per_object = data.object_size / data.op_size;
+
+  srand (time(NULL));
+
+  r = completions_init(concurrentios);
+  if (r < 0)
+    return r;
+
+  //set up initial reads
+  for (int i = 0; i < concurrentios; ++i) {
+    name[i] = generate_object_name(i / writes_per_object, pid);
+    contents[i] = new bufferlist();
+  }
+
+  lock.Lock();
+  data.finished = 0;
+  data.start_time = ceph_clock_now();
+  lock.Unlock();
+
+  pthread_t print_thread;
+  pthread_create(&print_thread, NULL, status_printer, (void *)this);
+  ceph_pthread_setname(print_thread, "rand_read_stat");
+
+  utime_t finish_time = data.start_time + time_to_run;
+  //start initial reads
+  for (int i = 0; i < concurrentios; ++i) {
+    index[i] = i;
+    start_times[i] = ceph_clock_now();
+    create_completion(i, _aio_cb, (void *)&lc);
+    r = aio_read(name[i], i, contents[i], data.op_size,
+                data.op_size * (i % writes_per_object));
+    if (r < 0) { //naughty, doesn't clean up heap -- oh, or handle the print thread!
+      cerr << "r = " << r << std::endl;
+      goto ERR;
+    }
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    lock.Unlock();
+  }
+
+  //keep on adding new reads as old ones complete
+  int slot;
+  bufferlist *cur_contents;
+  int rand_id;
+
+  slot = 0;
+  while ((!seconds_to_run || ceph_clock_now() < finish_time)) {
+    lock.Lock();
+    int old_slot = slot;
+    bool found = false;
+    while (1) {
+      do {
+        if (completion_is_done(slot)) {
+          found = true;
+          break;
+        }
+        slot++;
+        if (slot == concurrentios) {
+          slot = 0;
+        }
+      } while (slot != old_slot);
+      if (found) {
+        break;
+      }
+      lc.cond.Wait(lock);
+    }
+
+    // calculate latency here, so memcmp doesn't inflate it
+    data.cur_latency = ceph_clock_now() - start_times[slot];
+
+    lock.Unlock();
+
+    int current_index = index[slot];
+    cur_contents = contents[slot];
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r < 0) {
+      cerr << "read got " << r << std::endl;
+      lock.Unlock();
+      goto ERR;
+    }
+
+    total_latency += data.cur_latency;
+    if (data.cur_latency > data.max_latency) data.max_latency = data.cur_latency;
+    if (data.cur_latency < data.min_latency) data.min_latency = data.cur_latency;
+    ++data.finished;
+    data.avg_latency = total_latency / data.finished;
+    --data.in_flight;
+    lock.Unlock();
+    
+    if (!no_verify) {
+      snprintf(data.object_contents, data.op_size, "I'm the %16dth op!", current_index);
+      if ((cur_contents->length() != data.op_size) || 
+          (memcmp(data.object_contents, cur_contents->c_str(), data.op_size) != 0)) {
+        cerr << name[slot] << " is not correct!" << std::endl;
+        ++errors;
+      }
+    } 
+
+    rand_id = rand() % num_objects;
+    newName = generate_object_name(rand_id / writes_per_object, pid);
+    index[slot] = rand_id;
+    release_completion(slot);
+
+    // invalidate internal crc cache
+    cur_contents->invalidate_crc();
+
+    //start new read and check data if requested
+    start_times[slot] = ceph_clock_now();
+    create_completion(slot, _aio_cb, (void *)&lc);
+    r = aio_read(newName, slot, contents[slot], data.op_size,
+                data.op_size * (rand_id % writes_per_object));
+    if (r < 0) {
+      goto ERR;
+    }
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    lock.Unlock();
+    name[slot] = newName;
+  }
+
+
+  //wait for final reads to complete
+  while (data.finished < data.started) {
+    slot = data.finished % concurrentios;
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r < 0) {
+      cerr << "read got " << r << std::endl;
+      lock.Unlock();
+      goto ERR;
+    }
+    data.cur_latency = ceph_clock_now() - start_times[slot];
+    total_latency += data.cur_latency;
+    if (data.cur_latency > data.max_latency) data.max_latency = data.cur_latency;
+    if (data.cur_latency < data.min_latency) data.min_latency = data.cur_latency;
+    ++data.finished;
+    data.avg_latency = total_latency / data.finished;
+    --data.in_flight;
+    release_completion(slot);
+    if (!no_verify) {
+      snprintf(data.object_contents, data.op_size, "I'm the %16dth op!", index[slot]);
+      lock.Unlock();
+      if ((contents[slot]->length() != data.op_size) || 
+          (memcmp(data.object_contents, contents[slot]->c_str(), data.op_size) != 0)) {
+        cerr << name[slot] << " is not correct!" << std::endl;
+        ++errors;
+      }
+    } else {
+        lock.Unlock();
+    }
+    delete contents[slot];
+  }
+
+  runtime = ceph_clock_now() - data.start_time;
+  lock.Lock();
+  data.done = true;
+  lock.Unlock();
+
+  pthread_join(print_thread, NULL);
+
+  double bandwidth;
+  bandwidth = ((double)data.finished)*((double)data.op_size)/(double)runtime;
+  bandwidth = bandwidth/(1024*1024); // we want it in MB/sec
+
+  if (!formatter) {
+    out(cout) << "Total time run:       " << runtime << std::endl
+       << "Total reads made:     " << data.finished << std::endl
+       << "Read size:            " << data.op_size << std::endl
+       << "Object size:          " << data.object_size << std::endl
+       << "Bandwidth (MB/sec):   " << setprecision(6) << bandwidth << std::endl
+       << "Average IOPS:         " << (int)(data.finished/runtime) << std::endl
+       << "Stddev IOPS:          " << vec_stddev(data.history.iops) << std::endl
+       << "Max IOPS:             " << data.idata.max_iops << std::endl
+       << "Min IOPS:             " << data.idata.min_iops << std::endl
+       << "Average Latency(s):   " << data.avg_latency << std::endl
+       << "Max latency(s):       " << data.max_latency << std::endl
+       << "Min latency(s):       " << data.min_latency << std::endl;
+  } else {
+    formatter->dump_format("total_time_run", "%f", (double)runtime);
+    formatter->dump_format("total_reads_made", "%d", data.finished);
+    formatter->dump_format("read_size", "%d", data.op_size);
+    formatter->dump_format("object_size", "%d", data.object_size);
+    formatter->dump_format("bandwidth", "%f", bandwidth);
+    formatter->dump_format("average_iops", "%d", (int)(data.finished/runtime));
+    formatter->dump_format("stddev_iops", "%d", vec_stddev(data.history.iops));
+    formatter->dump_format("max_iops", "%d", data.idata.max_iops);
+    formatter->dump_format("min_iops", "%d", data.idata.min_iops);
+    formatter->dump_format("average_latency", "%f", data.avg_latency);
+    formatter->dump_format("max_latency", "%f", data.max_latency);
+    formatter->dump_format("min_latency", "%f", data.min_latency);
+  }
+  completions_done();
+
+  return (errors > 0 ? -EIO : 0);
+
+ ERR:
+  lock.Lock();
+  data.done = 1;
+  lock.Unlock();
+  pthread_join(print_thread, NULL);
+  return r;
+}
+
+int ObjBencher::clean_up(const std::string& orig_prefix, int concurrentios, const std::string& run_name) {
+  int r = 0;
+  uint64_t op_size, object_size;
+  int num_objects;
+  int prevPid;
+
+  // default meta object if user does not specify one
+  const std::string run_name_meta = (run_name.empty() ? BENCH_LASTRUN_METADATA : run_name);
+  const std::string prefix = (orig_prefix.empty() ? generate_object_prefix_nopid() : orig_prefix);
+
+  if (prefix.substr(0, BENCH_PREFIX.length()) != BENCH_PREFIX) {
+    cerr << "Specified --prefix invalid, it must begin with \"" << BENCH_PREFIX << "\"" << std::endl;
+    return -EINVAL;
+  }
+
+  std::list<Object> unfiltered_objects;
+  std::set<std::string> meta_namespaces, all_namespaces;
+
+  // If caller set all_nspaces this will be searching
+  // across multiple namespaces.
+  while (true) {
+    bool objects_remain = get_objects(&unfiltered_objects, 20);
+    if (!objects_remain)
+      break;
+
+    std::list<Object>::const_iterator i = unfiltered_objects.begin();
+    for ( ; i != unfiltered_objects.end(); ++i) {
+      if (i->first == run_name_meta) {
+        meta_namespaces.insert(i->second);
+      }
+      if (i->first.substr(0, prefix.length()) == prefix) {
+        all_namespaces.insert(i->second);
+      }
+    }
+  }
+
+  std::set<std::string>::const_iterator i = all_namespaces.begin();
+  for ( ; i != all_namespaces.end(); ++i) {
+    set_namespace(*i);
+
+    // if no metadata file found we should try to do a linear search on the prefix
+    if (meta_namespaces.find(*i) == meta_namespaces.end()) {
+      int r = clean_up_slow(prefix, concurrentios);
+      if (r < 0) {
+        cerr << "clean_up_slow error r= " << r << std::endl;
+        return r;
+      }
+      continue;
+    }
+
+    r = fetch_bench_metadata(run_name_meta, &op_size, &object_size, &num_objects, &prevPid);
+    if (r < 0) {
+      return r;
+    }
+
+    r = clean_up(num_objects, prevPid, concurrentios);
+    if (r != 0) return r;
+
+    r = sync_remove(run_name_meta);
+    if (r != 0) return r;
+  }
+
+  return 0;
+}
+
+int ObjBencher::clean_up(int num_objects, int prevPid, int concurrentios) {
+  lock_cond lc(&lock);
+  
+  if (concurrentios <= 0) 
+    return -EINVAL;
+
+  std::vector<string> name(concurrentios);
+  std::string newName;
+  int r = 0;
+  utime_t runtime;
+  int slot = 0;
+
+  lock.Lock();
+  data.done = false;
+  data.in_flight = 0;
+  data.started = 0;
+  data.finished = 0;
+  lock.Unlock();
+
+  // don't start more completions than files
+  if (num_objects == 0) {
+    return 0;
+  } else if (num_objects < concurrentios) {
+    concurrentios = num_objects;
+  }
+
+  r = completions_init(concurrentios);
+  if (r < 0)
+    return r;
+
+  //set up initial removes
+  for (int i = 0; i < concurrentios; ++i) {
+    name[i] = generate_object_name(i, prevPid);
+  }
+
+  //start initial removes
+  for (int i = 0; i < concurrentios; ++i) {
+    create_completion(i, _aio_cb, (void *)&lc);
+    r = aio_remove(name[i], i);
+    if (r < 0) { //naughty, doesn't clean up heap
+      cerr << "r = " << r << std::endl;
+      goto ERR;
+    }
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    lock.Unlock();
+  }
+
+  //keep on adding new removes as old ones complete
+  while (data.started < num_objects) {
+    lock.Lock();
+    int old_slot = slot;
+    bool found = false;
+    while (1) {
+      do {
+        if (completion_is_done(slot)) {
+          found = true;
+          break;
+        }
+        slot++;
+        if (slot == concurrentios) {
+          slot = 0;
+        }
+      } while (slot != old_slot);
+      if (found) {
+        break;
+      }
+      lc.cond.Wait(lock);
+    }
+    lock.Unlock();
+    newName = generate_object_name(data.started, prevPid);
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r != 0 && r != -ENOENT) { // file does not exist
+      cerr << "remove got " << r << std::endl;
+      lock.Unlock();
+      goto ERR;
+    }
+    ++data.finished;
+    --data.in_flight;
+    lock.Unlock();
+    release_completion(slot);
+
+    //start new remove and check data if requested
+    create_completion(slot, _aio_cb, (void *)&lc);
+    r = aio_remove(newName, slot);
+    if (r < 0) {
+      goto ERR;
+    }
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    lock.Unlock();
+    name[slot] = newName;
+  }
+
+  //wait for final removes to complete
+  while (data.finished < data.started) {
+    slot = data.finished % concurrentios;
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r != 0 && r != -ENOENT) { // file does not exist
+      cerr << "remove got " << r << std::endl;
+      lock.Unlock();
+      goto ERR;
+    }
+    ++data.finished;
+    --data.in_flight;
+    release_completion(slot);
+    lock.Unlock();
+  }
+
+  lock.Lock();
+  data.done = true;
+  lock.Unlock();
+
+  completions_done();
+
+  out(cout) << "Removed " << data.finished << " object" << (data.finished != 1 ? "s" : "") << std::endl;
+
+  return 0;
+
+ ERR:
+  lock.Lock();
+  data.done = 1;
+  lock.Unlock();
+  return r;
+}
+
+/**
+ * Return objects from the datastore which match a prefix.
+ *
+ * Clears the list and populates it with any objects which match the
+ * prefix. The list is guaranteed to have at least one item when the
+ * function returns true.
+ *
+ * @param prefix the prefix to match against
+ * @param objects [out] return list of objects
+ * @returns true if there are any objects in the store which match
+ * the prefix, false if there are no more
+ */
+bool ObjBencher::more_objects_matching_prefix(const std::string& prefix, std::list<Object>* objects) {
+  std::list<Object> unfiltered_objects;
+
+  objects->clear();
+
+  while (objects->empty()) {
+    bool objects_remain = get_objects(&unfiltered_objects, 20);
+    if (!objects_remain)
+      return false;
+
+    std::list<Object>::const_iterator i = unfiltered_objects.begin();
+    for ( ; i != unfiltered_objects.end(); ++i) {
+      if (i->first.substr(0, prefix.length()) == prefix) {
+        objects->push_back(*i);
+      }
+    }
+  }
+
+  return true;
+}
+
+int ObjBencher::clean_up_slow(const std::string& prefix, int concurrentios) {
+  lock_cond lc(&lock);
+
+  if (concurrentios <= 0) 
+    return -EINVAL;
+
+  std::vector<Object> name(concurrentios);
+  Object newName;
+  int r = 0;
+  utime_t runtime;
+  int slot = 0;
+  std::list<Object> objects;
+  bool objects_remain = true;
+
+  lock.Lock();
+  data.done = false;
+  data.in_flight = 0;
+  data.started = 0;
+  data.finished = 0;
+  lock.Unlock();
+
+  out(cout) << "Warning: using slow linear search" << std::endl;
+
+  r = completions_init(concurrentios);
+  if (r < 0)
+    return r;
+
+  //set up initial removes
+  for (int i = 0; i < concurrentios; ++i) {
+    if (objects.empty()) {
+      // if there are fewer objects than concurrent ios, don't generate extras
+      bool objects_found = more_objects_matching_prefix(prefix, &objects);
+      if (!objects_found) {
+        concurrentios = i;
+        objects_remain = false;
+        break;
+      }
+    }
+
+    name[i] = objects.front();
+    objects.pop_front();
+  }
+
+  //start initial removes
+  for (int i = 0; i < concurrentios; ++i) {
+    create_completion(i, _aio_cb, (void *)&lc);
+    set_namespace(name[i].second);
+    r = aio_remove(name[i].first, i);
+    if (r < 0) { //naughty, doesn't clean up heap
+      cerr << "r = " << r << std::endl;
+      goto ERR;
+    }
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    lock.Unlock();
+  }
+
+  //keep on adding new removes as old ones complete
+  while (objects_remain) {
+    lock.Lock();
+    int old_slot = slot;
+    bool found = false;
+    while (1) {
+      do {
+        if (completion_is_done(slot)) {
+          found = true;
+          break;
+        }
+        slot++;
+        if (slot == concurrentios) {
+          slot = 0;
+        }
+      } while (slot != old_slot);
+      if (found) {
+        break;
+      }
+      lc.cond.Wait(lock);
+    }
+    lock.Unlock();
+
+    // get more objects if necessary
+    if (objects.empty()) {
+      objects_remain = more_objects_matching_prefix(prefix, &objects);
+      // quit if there are no more
+      if (!objects_remain) {
+        break;
+      }
+    }
+
+    // get the next object
+    newName = objects.front();
+    objects.pop_front();
+
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r != 0 && r != -ENOENT) { // file does not exist
+      cerr << "remove got " << r << std::endl;
+      lock.Unlock();
+      goto ERR;
+    }
+    ++data.finished;
+    --data.in_flight;
+    lock.Unlock();
+    release_completion(slot);
+
+    //start new remove and check data if requested
+    create_completion(slot, _aio_cb, (void *)&lc);
+    set_namespace(newName.second);
+    r = aio_remove(newName.first, slot);
+    if (r < 0) {
+      goto ERR;
+    }
+    lock.Lock();
+    ++data.started;
+    ++data.in_flight;
+    lock.Unlock();
+    name[slot] = newName;
+  }
+
+  //wait for final removes to complete
+  while (data.finished < data.started) {
+    slot = data.finished % concurrentios;
+    completion_wait(slot);
+    lock.Lock();
+    r = completion_ret(slot);
+    if (r != 0 && r != -ENOENT) { // file does not exist
+      cerr << "remove got " << r << std::endl;
+      lock.Unlock();
+      goto ERR;
+    }
+    ++data.finished;
+    --data.in_flight;
+    release_completion(slot);
+    lock.Unlock();
+  }
+
+  lock.Lock();
+  data.done = true;
+  lock.Unlock();
+
+  completions_done();
+
+  out(cout) << "Removed " << data.finished << " object" << (data.finished != 1 ? "s" : "") << std::endl;
+
+  return 0;
+
+ ERR:
+  lock.Lock();
+  data.done = 1;
+  lock.Unlock();
+  return -EIO;
+}