librados: make querying pools for selfmanaged snaps reliable

If get_pool_is_selfmanaged_snaps_mode() is invoked on a fresh RADOS
client instance that still lacks an osdmap, it returns false, same as
for "this pool is not in selfmanaged snaps mode".  The same happens if
the pool in question doesn't exist since the signature doesn't allow to
return an error.

The motivation for this API was to prevent users from running "rados
cppool" on a pool with unmanaged snapshots and deleting the original
thinking that they have a full copy.  Unfortunately, it's exactly
"rados cppool" that fell into this trap, so no warning is printed and
--yes-i-really-mean-it flag isn't enforced.

Fixes: https://tracker.ceph.com/issues/63607
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
(cherry picked from commit 0999e63bfbbee46b8e19c3f05881eee64dba8b5e)

Conflicts:
	PendingReleaseNotes [ moved to >=17.2.8 section ]

diff --git a/PendingReleaseNotes b/PendingReleaseNotes
index 310c8561d35f4f7bd1ba5795cfba082afb03aa51..6789c409df0119ad38c3dd2c1bd95ccf29f76b74 100644 (file)
--- a/PendingReleaseNotes
+++ b/PendingReleaseNotes
@@ -1,3 +1,10 @@
+>=17.2.8
+--------
+
+* RADOS: `get_pool_is_selfmanaged_snaps_mode` C++ API has been deprecated
+  due to being prone to false negative results.  It's safer replacement is
+  `pool_is_in_selfmanaged_snaps_mode`.
+
 >=17.2.7
 --------
 

diff --git a/src/include/rados/librados.hpp b/src/include/rados/librados.hpp
index 76021700ae66827a3374d1403b0a8b5fc97058d1..9dd1b3e2569ac8a13c9af19eb34f8ea9ceffadbc 100644 (file)
--- a/src/include/rados/librados.hpp
+++ b/src/include/rados/librados.hpp
@@ -1474,8 +1474,11 @@ inline namespace v14_2_0 {
     int get_pool_stats(std::list<std::string>& v,
                        std::string& category,
                       std::map<std::string, stats_map>& stats);
+
     /// check if pool has or had selfmanaged snaps
-    bool get_pool_is_selfmanaged_snaps_mode(const std::string& poolname);
+    bool get_pool_is_selfmanaged_snaps_mode(const std::string& poolname)
+      __attribute__ ((deprecated));
+    int pool_is_in_selfmanaged_snaps_mode(const std::string& poolname);
 
     int cluster_stat(cluster_stat_t& result);
     int cluster_fsid(std::string *fsid);

diff --git a/src/librados/RadosClient.cc b/src/librados/RadosClient.cc
index 43914a89c2c182234f4063cafd87d9e40a505ea1..1662e0004e78e1c6e53006250f109d64964fa66b 100644 (file)
--- a/src/librados/RadosClient.cc
+++ b/src/librados/RadosClient.cc
@@ -631,16 +631,22 @@ int librados::RadosClient::get_pool_stats(std::list<string>& pools,
   return 0;
 }
 
-bool librados::RadosClient::get_pool_is_selfmanaged_snaps_mode(
+int librados::RadosClient::pool_is_in_selfmanaged_snaps_mode(
   const std::string& pool)
 {
-  bool ret = false;
-  objecter->with_osdmap([&](const OSDMap& osdmap) {
+  int r = wait_for_osdmap();
+  if (r < 0) {
+    return r;
+  }
+
+  return objecter->with_osdmap([&pool](const OSDMap& osdmap) {
       int64_t poolid = osdmap.lookup_pg_pool_name(pool);
-      if (poolid >= 0)
-       ret = osdmap.get_pg_pool(poolid)->is_unmanaged_snaps_mode();
+      if (poolid < 0) {
+        return -ENOENT;
+      }
+      return static_cast<int>(
+        osdmap.get_pg_pool(poolid)->is_unmanaged_snaps_mode());
     });
-  return ret;
 }
 
 int librados::RadosClient::get_fs_stats(ceph_statfs& stats)

diff --git a/src/librados/RadosClient.h b/src/librados/RadosClient.h
index 00a273b82d30dab7486c9a969b81c5e5993d7372..068153bb81bb3db0cc0023107e40d6fe22678ea8 100644 (file)
--- a/src/librados/RadosClient.h
+++ b/src/librados/RadosClient.h
@@ -131,7 +131,7 @@ public:
   int get_pool_stats(std::list<std::string>& ls, std::map<std::string,::pool_stat_t> *result,
     bool *per_pool);
   int get_fs_stats(ceph_statfs& result);
-  bool get_pool_is_selfmanaged_snaps_mode(const std::string& pool);
+  int pool_is_in_selfmanaged_snaps_mode(const std::string& pool);
 
   /*
   -1 was set as the default value and monitor will pickup the right crush rule with below order:

diff --git a/src/librados/librados_cxx.cc b/src/librados/librados_cxx.cc
index 52925b4013f50cb2b68e35d4ca36c7c606b25556..c4b0f60896600f0a24877f0d9e333218090e1b2b 100644 (file)
--- a/src/librados/librados_cxx.cc
+++ b/src/librados/librados_cxx.cc
@@ -2719,9 +2719,16 @@ int librados::Rados::get_pool_stats(std::list<string>& v,
   return -EOPNOTSUPP;
 }
 
+// deprecated, use pool_is_in_selfmanaged_snaps_mode() instead
 bool librados::Rados::get_pool_is_selfmanaged_snaps_mode(const std::string& pool)
 {
-  return client->get_pool_is_selfmanaged_snaps_mode(pool);
+  // errors are ignored, prone to false negative results
+  return client->pool_is_in_selfmanaged_snaps_mode(pool) > 0;
+}
+
+int librados::Rados::pool_is_in_selfmanaged_snaps_mode(const std::string& pool)
+{
+  return client->pool_is_in_selfmanaged_snaps_mode(pool);
 }
 
 int librados::Rados::cluster_stat(cluster_stat_t& result)

diff --git a/src/test/librados/snapshots_cxx.cc b/src/test/librados/snapshots_cxx.cc
index dee17ddb8d7a3d4abefab0957121bbef140ca5c4..2e74688643a6c09e0ffe328db98ebae841f9f674 100644 (file)
--- a/src/test/librados/snapshots_cxx.cc
+++ b/src/test/librados/snapshots_cxx.cc
@@ -24,9 +24,9 @@ TEST_F(LibRadosSnapshotsPP, SnapListPP) {
   bufferlist bl1;
   bl1.append(buf, sizeof(buf));
   ASSERT_EQ(0, ioctx.write("foo", bl1, sizeof(buf), 0));
-  ASSERT_FALSE(cluster.get_pool_is_selfmanaged_snaps_mode(pool_name));
+  ASSERT_EQ(0, cluster.pool_is_in_selfmanaged_snaps_mode(pool_name));
   ASSERT_EQ(0, ioctx.snap_create("snap1"));
-  ASSERT_FALSE(cluster.get_pool_is_selfmanaged_snaps_mode(pool_name));
+  ASSERT_EQ(0, cluster.pool_is_in_selfmanaged_snaps_mode(pool_name));
   std::vector<snap_t> snaps;
   EXPECT_EQ(0, ioctx.snap_list(&snaps));
   EXPECT_EQ(1U, snaps.size());
@@ -34,7 +34,7 @@ TEST_F(LibRadosSnapshotsPP, SnapListPP) {
   EXPECT_EQ(0, ioctx.snap_lookup("snap1", &rid));
   EXPECT_EQ(rid, snaps[0]);
   EXPECT_EQ(0, ioctx.snap_remove("snap1"));
-  ASSERT_FALSE(cluster.get_pool_is_selfmanaged_snaps_mode(pool_name));
+  ASSERT_EQ(0, cluster.pool_is_in_selfmanaged_snaps_mode(pool_name));
 }
 
 TEST_F(LibRadosSnapshotsPP, SnapRemovePP) {
@@ -108,9 +108,9 @@ TEST_F(LibRadosSnapshotsPP, SnapCreateRemovePP) {
 TEST_F(LibRadosSnapshotsSelfManagedPP, SnapPP) {
   std::vector<uint64_t> my_snaps;
   my_snaps.push_back(-2);
-  ASSERT_FALSE(cluster.get_pool_is_selfmanaged_snaps_mode(pool_name));
+  ASSERT_EQ(0, cluster.pool_is_in_selfmanaged_snaps_mode(pool_name));
   ASSERT_EQ(0, ioctx.selfmanaged_snap_create(&my_snaps.back()));
-  ASSERT_TRUE(cluster.get_pool_is_selfmanaged_snaps_mode(pool_name));
+  ASSERT_EQ(1, cluster.pool_is_in_selfmanaged_snaps_mode(pool_name));
   ::std::reverse(my_snaps.begin(), my_snaps.end()); 
   ASSERT_EQ(0, ioctx.selfmanaged_snap_set_write_ctx(my_snaps[0], my_snaps));
   ::std::reverse(my_snaps.begin(), my_snaps.end());
@@ -147,7 +147,7 @@ TEST_F(LibRadosSnapshotsSelfManagedPP, SnapPP) {
   ASSERT_EQ(0, ioctx.selfmanaged_snap_remove(my_snaps.back()));
   my_snaps.pop_back();
   ioctx.snap_set_read(LIBRADOS_SNAP_HEAD);
-  ASSERT_TRUE(cluster.get_pool_is_selfmanaged_snaps_mode(pool_name));
+  ASSERT_EQ(1, cluster.pool_is_in_selfmanaged_snaps_mode(pool_name));
   ASSERT_EQ(0, ioctx.remove("foo"));
 }
 
@@ -458,7 +458,7 @@ TEST_F(LibRadosSnapshotsSelfManagedPP, ReusePurgedSnap) {
   std::vector<uint64_t> my_snaps;
   my_snaps.push_back(-2);
   ASSERT_EQ(0, ioctx.selfmanaged_snap_create(&my_snaps.back()));
-  ASSERT_TRUE(cluster.get_pool_is_selfmanaged_snaps_mode(pool_name));
+  ASSERT_EQ(1, cluster.pool_is_in_selfmanaged_snaps_mode(pool_name));
   ::std::reverse(my_snaps.begin(), my_snaps.end());
   ASSERT_EQ(0, ioctx.selfmanaged_snap_set_write_ctx(my_snaps[0], my_snaps));
   ::std::reverse(my_snaps.begin(), my_snaps.end());
@@ -497,6 +497,52 @@ TEST_F(LibRadosSnapshotsSelfManagedPP, ReusePurgedSnap) {
   //sleep(600);
 }
 
+TEST(LibRadosPoolIsInSelfmanagedSnapsMode, NotConnected) {
+  librados::Rados cluster;
+  ASSERT_EQ(0, cluster.init(nullptr));
+
+  EXPECT_EQ(-ENOTCONN, cluster.pool_is_in_selfmanaged_snaps_mode("foo"));
+}
+
+TEST(LibRadosPoolIsInSelfmanagedSnapsMode, FreshInstance) {
+  librados::Rados cluster1;
+  std::string pool_name = get_temp_pool_name();
+  ASSERT_EQ("", create_one_pool_pp(pool_name, cluster1));
+  EXPECT_EQ(0, cluster1.pool_is_in_selfmanaged_snaps_mode(pool_name));
+  {
+    librados::Rados cluster2;
+    ASSERT_EQ("", connect_cluster_pp(cluster2));
+    EXPECT_EQ(0, cluster2.pool_is_in_selfmanaged_snaps_mode(pool_name));
+  }
+
+  librados::IoCtx ioctx;
+  cluster1.ioctx_create(pool_name.c_str(), ioctx);
+  uint64_t snap_id;
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_create(&snap_id));
+  EXPECT_EQ(1, cluster1.pool_is_in_selfmanaged_snaps_mode(pool_name));
+  {
+    librados::Rados cluster2;
+    ASSERT_EQ("", connect_cluster_pp(cluster2));
+    EXPECT_EQ(1, cluster2.pool_is_in_selfmanaged_snaps_mode(pool_name));
+  }
+
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_remove(snap_id));
+  EXPECT_EQ(1, cluster1.pool_is_in_selfmanaged_snaps_mode(pool_name));
+  {
+    librados::Rados cluster2;
+    ASSERT_EQ("", connect_cluster_pp(cluster2));
+    EXPECT_EQ(1, cluster2.pool_is_in_selfmanaged_snaps_mode(pool_name));
+  }
+
+  ASSERT_EQ(0, cluster1.pool_delete(pool_name.c_str()));
+  EXPECT_EQ(-ENOENT, cluster1.pool_is_in_selfmanaged_snaps_mode(pool_name));
+  {
+    librados::Rados cluster2;
+    ASSERT_EQ("", connect_cluster_pp(cluster2));
+    EXPECT_EQ(-ENOENT, cluster2.pool_is_in_selfmanaged_snaps_mode(pool_name));
+  }
+}
+
 // EC testing
 TEST_F(LibRadosSnapshotsECPP, SnapListPP) {
   char buf[bufsize];

diff --git a/src/tools/rados/rados.cc b/src/tools/rados/rados.cc
index 11d9f1f7c65b28245f1c80830ab0a1ccba0b9d60..ed0381b5468f7606062af7a825ab183697facb80 100644 (file)
--- a/src/tools/rados/rados.cc
+++ b/src/tools/rados/rados.cc
@@ -3120,7 +3120,12 @@ static int rados_tool_common(const std::map < std::string, std::string > &opts,
     cerr << "WARNING: pool copy does not preserve user_version, which some "
         << "    apps may rely on." << std::endl;
 
-    if (rados.get_pool_is_selfmanaged_snaps_mode(src_pool)) {
+    ret = rados.pool_is_in_selfmanaged_snaps_mode(src_pool);
+    if (ret < 0) {
+      cerr << "failed to query pool " << src_pool << " for selfmanaged snaps: "
+           << cpp_strerror(ret) << std::endl;
+      return 1;
+    } else if (ret > 0) {
       cerr << "WARNING: pool " << src_pool << " has selfmanaged snaps, which are not preserved\n"
           << "    by the cppool operation.  This will break any snapshot user."
           << std::endl;
@@ -3213,7 +3218,12 @@ static int rados_tool_common(const std::map < std::string, std::string > &opts,
       return 1;
     }
 
-    if (rados.get_pool_is_selfmanaged_snaps_mode(pool_name)) {
+    ret = rados.pool_is_in_selfmanaged_snaps_mode(pool_name);
+    if (ret < 0) {
+      cerr << "failed to query pool " << pool_name << " for selfmanaged snaps: "
+           << cpp_strerror(ret) << std::endl;
+      return 1;
+    } else if (ret > 0) {
       cerr << "can't create snapshot: pool " << pool_name
            << " is in selfmanaged snaps mode" << std::endl;
       return 1;