From: Radoslaw Zarzynski <rzarzynski@mirantis.com>
Date: Thu, 22 Jan 2015 16:46:50 +0000 (+0100)
Subject: librados: rectify the pool name caching in IoCtxImpl.
X-Git-Tag: v0.93~51^2~2^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F3515%2Fhead;p=ceph.git

librados: rectify the pool name caching in IoCtxImpl.

Fixes: #10458
Signed-off-by: Radoslaw Zarzynski <rzarzynski@mirantis.com>
---

diff --git a/src/librados/IoCtxImpl.cc b/src/librados/IoCtxImpl.cc
index d8642176eea3..5ef56c0ec7fc 100644
--- a/src/librados/IoCtxImpl.cc
+++ b/src/librados/IoCtxImpl.cc
@@ -28,19 +28,19 @@
 librados::IoCtxImpl::IoCtxImpl() :
   ref_cnt(0), client(NULL), poolid(0), assert_ver(0), last_objver(0),
   notify_timeout(30), aio_write_list_lock("librados::IoCtxImpl::aio_write_list_lock"),
-  aio_write_seq(0), objecter(NULL)
+  aio_write_seq(0), cached_pool_names_lock("librados::IoCtxImpl::cached_pool_names_lock"),
+  objecter(NULL)
 {
 }
 
 librados::IoCtxImpl::IoCtxImpl(RadosClient *c, Objecter *objecter,
-			       int64_t poolid,
-			       const char *pool_name, snapid_t s)
-  : ref_cnt(0), client(c), poolid(poolid), pool_name(pool_name), snap_seq(s),
+			       int64_t poolid, snapid_t s)
+  : ref_cnt(0), client(c), poolid(poolid), snap_seq(s),
     assert_ver(0), last_objver(0),
     notify_timeout(c->cct->_conf->client_notify_timeout),
-    oloc(poolid),
-    aio_write_list_lock("librados::IoCtxImpl::aio_write_list_lock"),
-    aio_write_seq(0), objecter(objecter)
+    oloc(poolid), aio_write_list_lock("librados::IoCtxImpl::aio_write_list_lock"),
+    aio_write_seq(0), cached_pool_names_lock("librados::IoCtxImpl::cached_pool_names_lock"),
+    objecter(objecter)
 {
 }
 
@@ -146,6 +146,19 @@ void librados::IoCtxImpl::flush_aio_writes()
   aio_write_list_lock.Unlock();
 }
 
+const string& librados::IoCtxImpl::get_cached_pool_name()
+{
+  std::string pn;
+  client->pool_get_name(get_id(), &pn);
+
+  Mutex::Locker l(cached_pool_names_lock);
+
+  if (cached_pool_names.empty() || cached_pool_names.back() != pn)
+    cached_pool_names.push_back(pn);
+
+  return cached_pool_names.back();
+}
+
 // SNAPS
 
 int librados::IoCtxImpl::snap_create(const char *snapName)
diff --git a/src/librados/IoCtxImpl.h b/src/librados/IoCtxImpl.h
index ab73cfa390ff..df73b0326965 100644
--- a/src/librados/IoCtxImpl.h
+++ b/src/librados/IoCtxImpl.h
@@ -32,7 +32,6 @@ struct librados::IoCtxImpl {
   atomic_t ref_cnt;
   RadosClient *client;
   int64_t poolid;
-  string pool_name;
   snapid_t snap_seq;
   ::SnapContext snapc;
   uint64_t assert_ver;
@@ -47,17 +46,19 @@ struct librados::IoCtxImpl {
   xlist<AioCompletionImpl*> aio_write_list;
   map<ceph_tid_t, std::list<AioCompletionImpl*> > aio_write_waiters;
 
+  Mutex cached_pool_names_lock;
+  std::list<std::string> cached_pool_names;
+
   Objecter *objecter;
 
   IoCtxImpl();
   IoCtxImpl(RadosClient *c, Objecter *objecter,
-	    int64_t poolid, const char *pool_name, snapid_t s);
+	    int64_t poolid, snapid_t s);
 
   void dup(const IoCtxImpl& rhs) {
     // Copy everything except the ref count
     client = rhs.client;
     poolid = rhs.poolid;
-    pool_name = rhs.pool_name;
     snap_seq = rhs.snap_seq;
     snapc = rhs.snapc;
     assert_ver = rhs.assert_ver;
@@ -89,6 +90,8 @@ struct librados::IoCtxImpl {
     return poolid;
   }
 
+  const string& get_cached_pool_name();
+
   uint32_t get_object_hash_position(const std::string& oid);
   uint32_t get_object_pg_hash_position(const std::string& oid);
 
diff --git a/src/librados/RadosClient.cc b/src/librados/RadosClient.cc
index ad018325ed93..5440cfda86b8 100644
--- a/src/librados/RadosClient.cc
+++ b/src/librados/RadosClient.cc
@@ -348,20 +348,13 @@ int librados::RadosClient::create_ioctx(const char *name, IoCtxImpl **io)
     }
   }
 
-  *io = new librados::IoCtxImpl(this, objecter, poolid, name, CEPH_NOSNAP);
+  *io = new librados::IoCtxImpl(this, objecter, poolid, CEPH_NOSNAP);
   return 0;
 }
 
 int librados::RadosClient::create_ioctx(int64_t pool_id, IoCtxImpl **io)
 {
-  std::string pool_name;
-  int r = pool_get_name(pool_id, &pool_name);
-  if (r < 0) {
-    return r;
-  }
-
-  *io = new librados::IoCtxImpl(this, objecter, pool_id, pool_name.c_str(),
-                                CEPH_NOSNAP);
+  *io = new librados::IoCtxImpl(this, objecter, pool_id, CEPH_NOSNAP);
   return 0;
 }
 
diff --git a/src/librados/librados.cc b/src/librados/librados.cc
index decf175555ff..c012807d222a 100644
--- a/src/librados/librados.cc
+++ b/src/librados/librados.cc
@@ -1039,6 +1039,11 @@ std::string librados::IoCtx::get_pool_name()
   return s;
 }
 
+const std::string& librados::IoCtx::get_pool_name() const
+{
+  return io_ctx_impl->get_cached_pool_name();
+}
+
 uint64_t librados::IoCtx::get_instance_id() const
 {
   return io_ctx_impl->client->get_instance_id();
@@ -1787,11 +1792,6 @@ void librados::IoCtx::set_assert_src_version(const std::string& oid, uint64_t ve
   io_ctx_impl->set_assert_src_version(obj, ver);
 }
 
-const std::string& librados::IoCtx::get_pool_name() const
-{
-  return io_ctx_impl->pool_name;
-}
-
 void librados::IoCtx::locator_set_key(const string& key)
 {
   io_ctx_impl->oloc.key = key;
@@ -2759,16 +2759,23 @@ extern "C" int rados_ioctx_pool_stat(rados_ioctx_t io, struct rados_pool_stat_t
   tracepoint(librados, rados_ioctx_pool_stat_enter, io);
   librados::IoCtxImpl *io_ctx_impl = (librados::IoCtxImpl *)io;
   list<string> ls;
-  ls.push_back(io_ctx_impl->pool_name);
-  map<string, ::pool_stat_t> rawresult;
+  std::string pool_name;
 
-  int err = io_ctx_impl->client->get_pool_stats(ls, rawresult);
+  int err = io_ctx_impl->client->pool_get_name(io_ctx_impl->get_id(), &pool_name);
   if (err) {
     tracepoint(librados, rados_ioctx_pool_stat_exit, err, stats);
     return err;
   }
+  ls.push_back(pool_name);
 
-  ::pool_stat_t& r = rawresult[io_ctx_impl->pool_name];
+  map<string, ::pool_stat_t> rawresult;
+  err = io_ctx_impl->client->get_pool_stats(ls, rawresult);
+  if (err) {
+    tracepoint(librados, rados_ioctx_pool_stat_exit, err, stats);
+    return err;
+  }
+
+  ::pool_stat_t& r = rawresult[pool_name];
   stats->num_kb = SHIFT_ROUND_UP(r.stats.sum.num_bytes, 10);
   stats->num_bytes = r.stats.sum.num_bytes;
   stats->num_objects = r.stats.sum.num_objects;
@@ -3068,12 +3075,19 @@ extern "C" int rados_ioctx_get_pool_name(rados_ioctx_t io, char *s, unsigned max
 {
   tracepoint(librados, rados_ioctx_get_pool_name_enter, io, maxlen);
   librados::IoCtxImpl *ctx = (librados::IoCtxImpl *)io;
-  if (ctx->pool_name.length() >= maxlen) {
+  std::string pool_name;
+
+  int err = ctx->client->pool_get_name(ctx->get_id(), &pool_name);
+  if (err) {
+    tracepoint(librados, rados_ioctx_get_pool_name_exit, err, "");
+    return err;
+  }
+  if (pool_name.length() >= maxlen) {
     tracepoint(librados, rados_ioctx_get_pool_name_exit, -ERANGE, "");
     return -ERANGE;
   }
-  strcpy(s, ctx->pool_name.c_str());
-  int retval = ctx->pool_name.length();
+  strcpy(s, pool_name.c_str());
+  int retval = pool_name.length();
   tracepoint(librados, rados_ioctx_get_pool_name_exit, retval, s);
   return retval;
 }