ceph-fuse: create finisher threads after fork()

The ObjectCacher and MonClient classes both instantiate Finisher
threads.  We need to make sure they are created *after* the fork(2)
or else the process will fail to join() them on shutdown, and the
threads will not exist while fuse is doing useful work.

Put CephFuse on the heap and move all this initalization into the child
block, and make sure errors are passed back to the parent.

Fix-proposed-by: Alexandre Marangone <alexandre.maragone@inktank.com>
Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 4fa5f99a40792341d247e51488c37301da3c4e4f)

1 files changed, 32 insertions, 28 deletions

diff --git a/src/ceph_fuse.cc b/src/ceph_fuse.cc
index f7a8d1a2c73..77c70f29df0 100644
--- a/src/ceph_fuse.cc
+++ b/src/ceph_fuse.cc
@@ -81,29 +81,6 @@ int main(int argc, const char **argv, const char *envp[]) {
     cerr << std::endl;
   }
 
-  // get monmap
-  MonClient mc(g_ceph_context);
-  int ret = mc.build_initial_monmap();
-  if (ret == -EINVAL)
-    usage();
-
-  if (ret < 0)
-    return -1;
-
-  // start up network
-  Messenger *messenger = Messenger::create(g_ceph_context,
-					   entity_name_t::CLIENT(), "client",
-					   getpid());
-  Client *client = new Client(messenger, &mc);
-
-  messenger->set_default_policy(Messenger::Policy::lossy_client(0, 0));
-  messenger->set_policy(entity_name_t::TYPE_MDS,
-			Messenger::Policy::lossless_client(0, 0));
-
-  if (filer_flags) {
-    client->set_filer_flags(filer_flags);
-  }
-
   // we need to handle the forking ourselves.
   int fd[2] = {0, 0};  // parent's, child's
   pid_t childpid = 0;
@@ -130,10 +107,35 @@ int main(int argc, const char **argv, const char *envp[]) {
     if (restart_log)
       g_ceph_context->_log->start();
 
-    CephFuse cfuse(client, fd[1]);
+    // get monmap
+    Messenger *messenger;
+    Client *client;
+    CephFuse *cfuse;
+
+    MonClient mc(g_ceph_context);
+    int r = mc.build_initial_monmap();
+    if (r == -EINVAL)
+      usage();
+    if (r < 0)
+      goto out_mc_start_failed;
+
+    // start up network
+    messenger = Messenger::create(g_ceph_context,
+				  entity_name_t::CLIENT(), "client",
+				  getpid());
+    messenger->set_default_policy(Messenger::Policy::lossy_client(0, 0));
+    messenger->set_policy(entity_name_t::TYPE_MDS,
+			  Messenger::Policy::lossless_client(0, 0));
+
+    client = new Client(messenger, &mc);
+    if (filer_flags) {
+      client->set_filer_flags(filer_flags);
+    }
+
+    cfuse = new CephFuse(client, fd[1]);
 
     cout << "ceph-fuse[" << getpid() << "]: starting ceph client" << std::endl;
-    int r = messenger->start();
+    r = messenger->start();
     if (r < 0) {
       cerr << "ceph-fuse[" << getpid() << "]: ceph mount failed with " << cpp_strerror(-r) << std::endl;
       goto out_messenger_start_failed;
@@ -154,20 +156,21 @@ int main(int argc, const char **argv, const char *envp[]) {
       goto out_shutdown;
     }
 
-    r = cfuse.init(newargc, newargv);
+    r = cfuse->init(newargc, newargv);
     if (r != 0) {
       cerr << "ceph-fuse[" << getpid() << "]: fuse failed to initialize" << std::endl;
       goto out_client_unmount;
     }
     cerr << "ceph-fuse[" << getpid() << "]: starting fuse" << std::endl;
-    r = cfuse.loop();
+    r = cfuse->loop();
     cerr << "ceph-fuse[" << getpid() << "]: fuse finished with error " << r << std::endl;
 
   out_client_unmount:
     client->unmount();
     //cout << "unmounted" << std::endl;
 
-    cfuse.finalize();
+    cfuse->finalize();
+    delete cfuse;
 
   out_shutdown:
     client->shutdown();
@@ -177,6 +180,7 @@ int main(int argc, const char **argv, const char *envp[]) {
     messenger->wait();
   out_messenger_start_failed:
     delete client;
+  out_mc_start_failed:
 
     if (g_conf->daemonize) {
       //cout << "child signalling parent with " << r << std::endl;