Adding upstream version 18.2.2.upstream/18.2.2

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

1 files changed, 596 insertions, 0 deletions

diff --git a/src/test/erasure-code/TestErasureCodeClay.cc b/src/test/erasure-code/TestErasureCodeClay.cc
new file mode 100644
index 000000000..cb4740948
--- /dev/null
+++ b/src/test/erasure-code/TestErasureCodeClay.cc
@@ -0,0 +1,596 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph distributed storage system
+ *
+ * Copyright (C) 2018 Indian Institute of Science <office.ece@iisc.ac.in>
+ *
+ * Author: Myna Vajha <mynaramana@gmail.com>
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ * 
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+
+#include "crush/CrushWrapper.h"
+#include "include/stringify.h"
+#include "erasure-code/clay/ErasureCodeClay.h"
+#include "global/global_context.h"
+#include "common/config_proxy.h"
+#include "gtest/gtest.h"
+
+using namespace std;
+
+TEST(ErasureCodeClay, sanity_check_k)
+{
+  ErasureCodeClay clay(g_conf().get_val<std::string>("erasure_code_dir"));
+  ErasureCodeProfile profile;
+  profile["k"] = "1";
+  profile["m"] = "1";
+  ostringstream errors;
+  EXPECT_EQ(-EINVAL, clay.init(profile, &errors));
+  EXPECT_NE(std::string::npos, errors.str().find("must be >= 2"));
+}
+
+TEST(ErasureCodeClay, encode_decode)
+{
+  ostringstream errors;
+  ErasureCodeClay clay(g_conf().get_val<std::string>("erasure_code_dir"));
+  ErasureCodeProfile profile;
+  profile["k"] = "2";
+  profile["m"] = "2";
+  int r= clay.init(profile, &cerr);
+  EXPECT_EQ(0, r);
+
+#define LARGE_ENOUGH 2048
+  bufferptr in_ptr(buffer::create_page_aligned(LARGE_ENOUGH));
+  in_ptr.zero();
+  in_ptr.set_length(0);
+  const char *payload =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+  in_ptr.append(payload, strlen(payload));
+  bufferlist in;
+  in.push_back(in_ptr);
+  int want_to_encode[] = { 0, 1, 2, 3 };
+  map<int, bufferlist> encoded;
+  EXPECT_EQ(0, clay.encode(set<int>(want_to_encode, want_to_encode+4),
+			   in,
+			   &encoded));
+  EXPECT_EQ(4u, encoded.size());
+  unsigned length =  encoded[0].length();
+  EXPECT_EQ(0, memcmp(encoded[0].c_str(), in.c_str(), length));
+  EXPECT_EQ(0, memcmp(encoded[1].c_str(), in.c_str() + length,
+                      in.length() - length));
+
+
+  // all chunks are available
+  {
+    int want_to_decode[] = { 0, 1 };
+    map<int, bufferlist> decoded;
+    EXPECT_EQ(0, clay._decode(set<int>(want_to_decode, want_to_decode+2),
+			      encoded,
+			      &decoded));
+    EXPECT_EQ(2u, decoded.size()); 
+    EXPECT_EQ(length, decoded[0].length());
+    EXPECT_EQ(0, memcmp(decoded[0].c_str(), in.c_str(), length));
+    EXPECT_EQ(0, memcmp(decoded[1].c_str(), in.c_str() + length,
+			in.length() - length));
+  }
+
+  // check all two chunks missing possibilities and recover them
+  for (int i=1; i<4; i++) {
+    for (int j=0; j<i; j++) {
+      map<int, bufferlist> degraded = encoded;
+      degraded.erase(j);
+      degraded.erase(i);
+      EXPECT_EQ(2u, degraded.size());
+      int want_to_decode[] = {j,i};
+      map<int, bufferlist> decoded;
+      EXPECT_EQ(0, clay._decode(set<int>(want_to_decode, want_to_decode+2),
+				degraded,
+				&decoded));
+      EXPECT_EQ(4u, decoded.size()); 
+      EXPECT_EQ(length, decoded[j].length());
+      EXPECT_EQ(0, memcmp(decoded[j].c_str(), encoded[j].c_str(), length));
+      EXPECT_EQ(0, memcmp(decoded[i].c_str(), encoded[i].c_str(), length));
+    }
+  }
+  //check for all one chunk missing possibilities
+  int sc_size = length/clay.sub_chunk_no;
+  int avail[] = {0,1,2,3};
+  for (int i=0; i < 4; i++) {
+    set<int> want_to_read;
+    want_to_read.insert(i);
+    set<int> available(avail, avail+4);
+    available.erase(i);
+    map<int, vector<pair<int,int>>> minimum;
+    EXPECT_EQ(0, clay.minimum_to_decode(want_to_read, available, &minimum));
+    map<int, bufferlist> helper;
+    for (map<int, vector<pair<int,int>>>::iterator h=minimum.begin(); h!= minimum.end(); ++h) {
+      for(vector<pair<int,int>>::iterator ind=h->second.begin(); ind != h->second.end(); ++ind) {
+	bufferlist temp;
+	temp.substr_of(encoded[h->first], ind->first*sc_size, ind->second*sc_size);
+	helper[h->first].append(temp);
+      }
+    }
+    for (map<int, vector<pair<int,int>>>::iterator h=minimum.begin(); h!= minimum.end(); ++h) {
+      EXPECT_EQ(length/clay.q, helper[h->first].length());
+    }
+    EXPECT_EQ(3u, helper.size());
+    map<int, bufferlist> decoded;
+    EXPECT_EQ(0, clay.decode(want_to_read, helper, &decoded, length));
+    EXPECT_EQ(1u, decoded.size());
+    EXPECT_EQ(0, memcmp(decoded[i].c_str(), encoded[i].c_str(), length));
+  }
+}
+
+
+TEST(ErasureCodeClay, encode_decode_aloof_nodes)
+{
+  ostringstream errors;
+  ErasureCodeClay clay(g_conf().get_val<std::string>("erasure_code_dir"));
+  ErasureCodeProfile profile;
+  profile["k"] = "3";
+  profile["m"] = "3";
+  profile["d"] = "4";
+  int r= clay.init(profile, &cerr);
+  EXPECT_EQ(0, r);
+
+#define LARGE_ENOUGH 2048
+  bufferptr in_ptr(buffer::create_page_aligned(LARGE_ENOUGH));
+  in_ptr.zero();
+  in_ptr.set_length(0);
+  const char *payload =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+  in_ptr.append(payload, strlen(payload));
+  bufferlist in;
+  in.push_back(in_ptr);
+  int want_to_encode[] = { 0, 1, 2, 3, 4, 5 };
+  map<int, bufferlist> encoded;
+  EXPECT_EQ(0, clay.encode(set<int>(want_to_encode, want_to_encode+6),
+			   in,
+			   &encoded));
+  EXPECT_EQ(6u, encoded.size());
+  unsigned length =  encoded[0].length();
+  if (in.length() < length) {
+    EXPECT_EQ(0, memcmp(encoded[0].c_str(), in.c_str(), in.length()));
+  } else if (in.length() <= 2*length ) {
+    EXPECT_EQ(0, memcmp(encoded[0].c_str(), in.c_str(), in.length()));
+    EXPECT_EQ(0, memcmp(encoded[1].c_str(), in.c_str()+length, in.length()-length));
+  } else {
+    EXPECT_EQ(1, in.length() <= 3*length);
+    EXPECT_EQ(0, memcmp(encoded[0].c_str(), in.c_str(), in.length()));
+    EXPECT_EQ(0, memcmp(encoded[1].c_str(), in.c_str()+length, length));
+    EXPECT_EQ(0, memcmp(encoded[2].c_str(), in.c_str()+2*length, in.length()-2*length));
+  }
+
+  // all chunks are available
+  {
+    int want_to_decode[] = { 0, 1, 2 };
+    map<int, bufferlist> decoded;
+    EXPECT_EQ(0, clay._decode(set<int>(want_to_decode, want_to_decode+3),
+			      encoded,
+			      &decoded));
+    EXPECT_EQ(3u, decoded.size()); 
+    EXPECT_EQ(length, decoded[0].length());
+    EXPECT_EQ(0, memcmp(decoded[0].c_str(), encoded[0].c_str(), length));
+    EXPECT_EQ(0, memcmp(decoded[1].c_str(), encoded[1].c_str(), length));
+    EXPECT_EQ(0, memcmp(decoded[2].c_str(), encoded[2].c_str(), length));
+  }
+
+  // check all three chunks missing possibilities and recover them
+  for (int i=2; i<6; i++) {
+    for (int j=1; j<i; j++) {
+      for(int k=0; k<j; k++) {
+	map<int, bufferlist> degraded = encoded;
+	degraded.erase(k);
+	degraded.erase(j);
+	degraded.erase(i);
+	EXPECT_EQ(3u, degraded.size());
+	int want_to_decode[] = {k,j,i};
+	map<int, bufferlist> decoded;
+	EXPECT_EQ(0, clay._decode(set<int>(want_to_decode, want_to_decode+3),
+				  degraded,
+				  &decoded));
+	EXPECT_EQ(6u, decoded.size()); 
+	EXPECT_EQ(length, decoded[j].length());
+	EXPECT_EQ(0, memcmp(decoded[k].c_str(), encoded[k].c_str(), length));
+	EXPECT_EQ(0, memcmp(decoded[j].c_str(), encoded[j].c_str(), length));
+	EXPECT_EQ(0, memcmp(decoded[i].c_str(), encoded[i].c_str(), length));
+      }
+    }
+  }
+  //check for all one chunk missing possibilities
+  int sc_size = length/clay.sub_chunk_no;
+  int avail[] = {0,1,2,3,4,5};
+  for (int i=0; i < 6; i++) {
+    vector<pair<int,int>> repair_subchunks;
+    map<int, vector<pair<int,int>>> minimum;
+    set<int> want_to_read;
+    want_to_read.insert(i);
+    set<int> available(avail, avail+6);
+    available.erase(i);
+    clay.minimum_to_decode(want_to_read, available, &minimum);
+    map<int, bufferlist> helper;
+    for (map<int, vector<pair<int,int>>>::iterator h=minimum.begin(); h!= minimum.end(); ++h) {
+      for(vector<pair<int,int>>::iterator ind=h->second.begin(); ind != h->second.end(); ++ind) {
+	bufferlist temp;
+	temp.substr_of(encoded[h->first], ind->first*sc_size, ind->second*sc_size);
+	helper[h->first].append(temp);
+      }
+    }  
+    for (map<int, vector<pair<int,int>>>::iterator h=minimum.begin(); h!= minimum.end(); ++h) {
+      EXPECT_EQ(length/clay.q, helper[h->first].length());
+    }
+    EXPECT_EQ((unsigned)clay.d, helper.size());
+    map<int, bufferlist> decoded;
+    EXPECT_EQ(0, clay.decode(want_to_read, helper, &decoded, length));
+    EXPECT_EQ(1u, decoded.size());
+    EXPECT_EQ(0, memcmp(decoded[i].c_str(), encoded[i].c_str(), length));
+  }
+}
+
+TEST(ErasureCodeClay, encode_decode_shortening_case)
+{
+  ostringstream errors;
+  ErasureCodeClay clay(g_conf().get_val<std::string>("erasure_code_dir"));
+  ErasureCodeProfile profile;
+  profile["k"] = "4";
+  profile["m"] = "3";
+  profile["d"] = "5";
+  int r= clay.init(profile, &cerr);
+  EXPECT_EQ(0, r);
+
+  EXPECT_EQ(2, clay.q);
+  EXPECT_EQ(4, clay.t);
+  EXPECT_EQ(1, clay.nu);
+
+  bufferptr in_ptr(buffer::create_page_aligned(LARGE_ENOUGH));
+  in_ptr.zero();
+  in_ptr.set_length(0);
+  const char *payload =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+  in_ptr.append(payload, strlen(payload));
+  bufferlist in;
+  in.push_back(in_ptr);
+  int want_to_encode[] = { 0, 1, 2, 3, 4, 5, 6 };
+  map<int, bufferlist> encoded;
+  EXPECT_EQ(0, clay.encode(set<int>(want_to_encode, want_to_encode+7),
+			   in,
+			   &encoded));
+  EXPECT_EQ(7u, encoded.size());
+  unsigned length =  encoded[0].length();
+  if (in.length() < length) {
+    EXPECT_EQ(0, memcmp(encoded[0].c_str(), in.c_str(), in.length()));
+  } else if (in.length() <= 2*length) {
+    EXPECT_EQ(0, memcmp(encoded[0].c_str(), in.c_str(), in.length()));
+    EXPECT_EQ(0, memcmp(encoded[1].c_str(), in.c_str()+length, in.length()-length));
+  } else if (in.length() <= 3*length) {
+    EXPECT_EQ(0, memcmp(encoded[0].c_str(), in.c_str(), in.length()));
+    EXPECT_EQ(0, memcmp(encoded[1].c_str(), in.c_str()+length, length));
+    EXPECT_EQ(0, memcmp(encoded[2].c_str(), in.c_str()+2*length, in.length()-2*length));
+  } else {
+    EXPECT_EQ(1, in.length() <= 4*length);
+    EXPECT_EQ(0, memcmp(encoded[0].c_str(), in.c_str(), in.length()));
+    EXPECT_EQ(0, memcmp(encoded[1].c_str(), in.c_str()+length, length));
+    EXPECT_EQ(0, memcmp(encoded[2].c_str(), in.c_str()+2*length, length));
+    EXPECT_EQ(0, memcmp(encoded[3].c_str(), in.c_str()+3*length, in.length()-3*length));
+  }
+
+  // all chunks are available
+  {
+    int want_to_decode[] = { 0, 1, 2, 3 };
+    map<int, bufferlist> decoded;
+    EXPECT_EQ(0, clay._decode(set<int>(want_to_decode, want_to_decode+4),
+			      encoded,
+			      &decoded));
+    EXPECT_EQ(4u, decoded.size()); 
+    EXPECT_EQ(length, decoded[0].length());
+    EXPECT_EQ(0, memcmp(decoded[0].c_str(), encoded[0].c_str(), length));
+    EXPECT_EQ(0, memcmp(decoded[1].c_str(), encoded[1].c_str(), length));
+    EXPECT_EQ(0, memcmp(decoded[2].c_str(), encoded[2].c_str(), length));
+    EXPECT_EQ(0, memcmp(decoded[3].c_str(), encoded[3].c_str(), length));
+  }
+
+  // check all three chunks missing possibilities and recover them
+  for (int i=2; i<7; i++) {
+    for (int j=1; j<i; j++) {
+      for(int k=0; k<j; k++) {
+	map<int, bufferlist> degraded = encoded;
+	degraded.erase(k);
+	degraded.erase(j);
+	degraded.erase(i);
+	EXPECT_EQ(4u, degraded.size());
+	int want_to_decode[] = {k,j,i};
+	map<int, bufferlist> decoded;
+	EXPECT_EQ(0, clay._decode(set<int>(want_to_decode, want_to_decode+3),
+				  degraded,
+				  &decoded));
+	EXPECT_EQ(7u, decoded.size()); 
+	EXPECT_EQ(length, decoded[j].length());
+	EXPECT_EQ(0, memcmp(decoded[k].c_str(), encoded[k].c_str(), length));
+	EXPECT_EQ(0, memcmp(decoded[j].c_str(), encoded[j].c_str(), length));
+	EXPECT_EQ(0, memcmp(decoded[i].c_str(), encoded[i].c_str(), length));
+      }
+    }
+  }
+  //check for all one chunk missing possibilities
+  int sc_size = length/clay.sub_chunk_no;
+  int avail[] = {0,1,2,3,4,5,6};
+  for (int i=0; i < 7; i++) {
+    vector<pair<int,int>> repair_subchunks;
+    map<int, vector<pair<int,int>>> minimum;
+    set<int> want_to_read;
+    want_to_read.insert(i);
+    set<int> available(avail, avail+7);
+    available.erase(i);
+    clay.minimum_to_decode(want_to_read, available, &minimum);
+    map<int, bufferlist> helper;
+    for (map<int, vector<pair<int,int>>>::iterator h=minimum.begin(); h!= minimum.end(); ++h) {
+      for(vector<pair<int,int>>::iterator ind=h->second.begin(); ind != h->second.end(); ++ind) {
+	bufferlist temp;
+	temp.substr_of(encoded[h->first], ind->first*sc_size, ind->second*sc_size);
+	helper[h->first].append(temp);
+      }
+    }  
+    for (map<int, vector<pair<int,int>>>::iterator h=minimum.begin(); h!= minimum.end(); ++h) {
+      EXPECT_EQ(length/clay.q, helper[h->first].length());
+    }
+    EXPECT_EQ(static_cast<size_t>(clay.d), helper.size());
+    map<int, bufferlist> decoded;
+    EXPECT_EQ(0, clay.decode(want_to_read, helper, &decoded, length));
+    EXPECT_EQ(1u, decoded.size());
+    EXPECT_EQ(length, decoded[i].length());
+    EXPECT_EQ(0, memcmp(decoded[i].c_str(), encoded[i].c_str(), length));
+  }
+}
+
+TEST(ErasureCodeClay, minimum_to_decode)
+{
+  ErasureCodeClay clay(g_conf().get_val<std::string>("erasure_code_dir"));
+  ErasureCodeProfile profile;
+  profile["k"] = "2";
+  profile["m"] = "2";
+  EXPECT_EQ(0, clay.init(profile, &cerr));
+
+  //
+  // If trying to read nothing, the minimum is empty.
+  //
+  {
+    set<int> want_to_read;
+    set<int> available_chunks;
+    set<int> minimum;
+
+    EXPECT_EQ(0, clay._minimum_to_decode(want_to_read,
+					 available_chunks,
+					 &minimum));
+    EXPECT_TRUE(minimum.empty());
+  }
+  //
+  // There is no way to read a chunk if none are available.
+  //
+  {
+    set<int> want_to_read;
+    set<int> available_chunks;
+    set<int> minimum;
+
+    want_to_read.insert(0);
+
+    EXPECT_EQ(-EIO, clay._minimum_to_decode(want_to_read,
+					    available_chunks,
+					    &minimum));
+  }
+  //
+  // Reading a subset of the available chunks is always possible.
+  //
+  {
+    set<int> want_to_read;
+    set<int> available_chunks;
+    set<int> minimum;
+
+    want_to_read.insert(0);
+    available_chunks.insert(0);
+
+    EXPECT_EQ(0, clay._minimum_to_decode(want_to_read,
+					 available_chunks,
+					 &minimum));
+    EXPECT_EQ(want_to_read, minimum);
+  }
+  //
+  // There is no way to read a missing chunk if there is less than k
+  // chunks available.
+  //
+  {
+    set<int> want_to_read;
+    set<int> available_chunks;
+    set<int> minimum;
+
+    want_to_read.insert(0);
+    want_to_read.insert(1);
+    available_chunks.insert(0);
+
+    EXPECT_EQ(-EIO, clay._minimum_to_decode(want_to_read,
+					    available_chunks,
+					    &minimum));
+  }
+  //
+  // When chunks are not available, the minimum can be made of any
+  // chunks. For instance, to read 1 and 3 below the minimum could be
+  // 2 and 3 which may seem better because it contains one of the
+  // chunks to be read. But it won't be more efficient than retrieving
+  // 0 and 2 instead because, in both cases, the decode function will
+  // need to run the same recovery operation and use the same amount
+  // of CPU and memory.
+  //
+  {
+    set<int> want_to_read;
+    set<int> available_chunks;
+    set<int> minimum;
+
+    want_to_read.insert(1);
+    want_to_read.insert(3);
+    available_chunks.insert(0);
+    available_chunks.insert(2);
+    available_chunks.insert(3);
+
+    EXPECT_EQ(0, clay._minimum_to_decode(want_to_read,
+					 available_chunks,
+					 &minimum));
+    EXPECT_EQ(2u, minimum.size());
+    EXPECT_EQ(0u, minimum.count(3));
+  }
+}
+
+TEST(ErasureCodeClay, encode)
+{
+  ErasureCodeClay clay(g_conf().get_val<std::string>("erasure_code_dir"));
+  ErasureCodeProfile profile;
+  profile["k"] = "2";
+  profile["m"] = "2";
+  EXPECT_EQ(0, clay.init(profile, &cerr));
+
+  unsigned aligned_object_size = clay.get_chunk_size(1) * 2 * 2;
+  {
+    //
+    // When the input bufferlist needs to be padded because
+    // it is not properly aligned, it is padded with zeros.
+    //
+    bufferlist in;
+    map<int,bufferlist> encoded;
+    int want_to_encode[] = { 0, 1, 2, 3 };
+    int trail_length = 1;
+    in.append(string(aligned_object_size + trail_length, 'X'));
+    EXPECT_EQ(0, clay.encode(set<int>(want_to_encode, want_to_encode+4),
+			     in,
+			     &encoded));
+    EXPECT_EQ(4u, encoded.size());
+    char *last_chunk = encoded[1].c_str();
+    int length =encoded[1].length();
+    EXPECT_EQ('X', last_chunk[0]);
+    EXPECT_EQ('\0', last_chunk[length - trail_length]);
+  }
+
+  {
+    //
+    // When only the first chunk is required, the encoded map only
+    // contains the first chunk. Although the clay encode
+    // internally allocated a buffer because of padding requirements
+    // and also computes the coding chunks, they are released before
+    // the return of the method, as shown when running the tests thru
+    // valgrind (there is no leak).
+    //
+    bufferlist in;
+    map<int,bufferlist> encoded;
+    set<int> want_to_encode;
+    want_to_encode.insert(0);
+    int trail_length = 1;
+    in.append(string(aligned_object_size + trail_length, 'X'));
+    EXPECT_EQ(0, clay.encode(want_to_encode, in, &encoded));
+    EXPECT_EQ(1u, encoded.size());
+  }
+}
+
+TEST(ErasureCodeClay, create_rule)
+{
+  std::unique_ptr<CrushWrapper> c = std::make_unique<CrushWrapper>();
+  c->create();
+  int root_type = 2;
+  c->set_type_name(root_type, "root");
+  int host_type = 1;
+  c->set_type_name(host_type, "host");
+  int osd_type = 0;
+  c->set_type_name(osd_type, "osd");
+
+  int rootno;
+  c->add_bucket(0, CRUSH_BUCKET_STRAW, CRUSH_HASH_RJENKINS1,
+		root_type, 0, NULL, NULL, &rootno);
+  c->set_item_name(rootno, "default");
+
+  map<string,string> loc;
+  loc["root"] = "default";
+
+  int num_host = 4;
+  int num_osd = 5;
+  int osd = 0;
+  for (int h=0; h<num_host; ++h) {
+    loc["host"] = string("host-") + stringify(h);
+    for (int o=0; o<num_osd; ++o, ++osd) {
+      c->insert_item(g_ceph_context, osd, 1.0, string("osd.") + stringify(osd), loc);
+    }
+  }
+
+  c->finalize();
+
+  {
+    stringstream ss;
+    ErasureCodeClay clay(g_conf().get_val<std::string>("erasure_code_dir"));
+    ErasureCodeProfile profile;
+    profile["k"] = "2";
+    profile["m"] = "2";
+    EXPECT_EQ(0, clay.init(profile, &cerr));
+    int ruleid = clay.create_rule("myrule", *c, &ss);
+    EXPECT_EQ(0, ruleid);
+    EXPECT_EQ(-EEXIST, clay.create_rule("myrule", *c, &ss));
+    //
+    // the minimum that is expected from the created rule is to
+    // successfully map get_chunk_count() devices from the crushmap,
+    // at least once.
+    //
+    vector<__u32> weight(c->get_max_devices(), 0x10000);
+    vector<int> out;
+    int x = 0;
+    c->do_rule(ruleid, x, out,   clay.get_chunk_count(), weight, 0);
+    ASSERT_EQ(out.size(), clay.get_chunk_count());
+    for (unsigned i=0; i<out.size(); ++i)
+      ASSERT_NE(CRUSH_ITEM_NONE, out[i]);
+  }
+  {
+    stringstream ss;
+    ErasureCodeClay clay(g_conf().get_val<std::string>("erasure_code_dir"));
+    ErasureCodeProfile profile;
+    profile["k"] = "2";
+    profile["m"] = "2";
+    profile["crush-root"] = "BAD";
+    EXPECT_EQ(0, clay.init(profile, &cerr));
+    EXPECT_EQ(-ENOENT, clay.create_rule("otherrule", *c, &ss));
+    EXPECT_EQ("root item BAD does not exist", ss.str());
+  }
+  {
+    stringstream ss;
+    ErasureCodeClay clay(g_conf().get_val<std::string>("erasure_code_dir"));
+    ErasureCodeProfile profile;
+    profile["k"] = "2";
+    profile["m"] = "2";
+    profile["crush-failure-domain"] = "WORSE";
+    EXPECT_EQ(0, clay.init(profile, &cerr));
+    EXPECT_EQ(-EINVAL, clay.create_rule("otherrule", *c, &ss));
+    EXPECT_EQ("unknown type WORSE", ss.str());
+  }
+}
+
+/* 
+ * Local Variables:
+ * compile-command: "cd ../.. ;
+ *   make -j4 unittest_erasure_code_clay &&
+ *   valgrind --tool=memcheck \
+ *      ./unittest_erasure_code_clay \
+ *      --gtest_filter=*.* --log-to-stderr=true --debug-osd=20"
+ * End:
+ */