ceph-fuse: test dentry invalidation options and fail out if we fail

We identify the Linux kernel version and based on that either expect to
be able to invalidate dentries effectively, or expect to be able to remount
the ceph-fuse mountpoint. Test it using the Client functions and callbacks by
spinning off a thread to invoke the test that is separate from the main
FUSE loop.

Most unfortunately, there doesn't seem to be a good interface to tell
FUSE to shut down if we need to do that. See
http://fuse.996288.n3.nabble.com/libfuse-exiting-fuse-session-loop-td10686.html
I tried changing our signal invocation or attempting a simple action on
the mount point but those were ineffectual at terminating the remaining
processes; fusermount actually gets rid of them all.

Signed-off-by: Greg Farnum <gfarnum@redhat.com>

diff --git a/src/ceph_fuse.cc b/src/ceph_fuse.cc
index 50406b92d1828180f3aecbfcd6b71aba54f02754..76168503d594c71b8ec4debeae32b18d69e48fc2 100644 (file)
--- a/src/ceph_fuse.cc
+++ b/src/ceph_fuse.cc
@@ -13,6 +13,7 @@
  */
 
 #include <sys/stat.h>
+#include <sys/utsname.h>
 #include <iostream>
 #include <string>
 using namespace std;
@@ -84,6 +85,8 @@ int main(int argc, const char **argv, const char *envp[]) {
   // we need to handle the forking ourselves.
   int fd[2] = {0, 0};  // parent's, child's
   pid_t childpid = 0;
+  int tester_r = 0;
+  void *tester_rp = NULL;
   bool restart_log = false;
   if (g_conf->daemonize) {
     int r = socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
@@ -107,13 +110,53 @@ int main(int argc, const char **argv, const char *envp[]) {
     if (restart_log)
       g_ceph_context->_log->start();
 
+    class RemountTest : public Thread {
+    public:
+      CephFuse *cfuse;
+      Client *client;
+      RemountTest() : Thread() {}
+      void init(CephFuse *cf, Client *cl) {
+       cfuse = cf;
+       client = cl;
+      }
+      virtual ~RemountTest() {}
+      virtual void *entry() {
+       struct utsname os_info;
+       int tr = uname(&os_info);
+       assert(tr == 0);
+       assert(memcmp(os_info.sysname, "Linux", 5) == 0);
+       int major, minor;       
+       char *end_num;
+       major = strtol(os_info.release, &end_num, 10);
+       assert(major > 0);
+       ++end_num;
+       minor = strtol(end_num, NULL, 10);
+       bool can_invalidate_dentries = g_conf->client_try_dentry_invalidate &&
+         (major < 3 ||
+          (major == 3 && minor < 18));
+       tr = client->test_dentry_handling(can_invalidate_dentries);
+       if (tr != 0) {
+         cerr << "ceph-fuse[" << getpid()
+              << "]: fuse failed dentry invalidate/remount test with error "
+              << cpp_strerror(tr) << ", stopping" << std::endl;
+
+         char buf[5050];
+         string mountpoint = cfuse->get_mount_point();
+         snprintf(buf, 5049, "fusermount -u -z %s", mountpoint.c_str());
+         system(buf);
+       }
+       return reinterpret_cast<void*>(tr);
+      }
+    } tester;
+
+
     // get monmap
     Messenger *messenger = NULL;
     Client *client;
     CephFuse *cfuse;
 
-    MonClient mc(g_ceph_context);
-    int r = mc.build_initial_monmap();
+    MonClient *mc = new MonClient(g_ceph_context);
+    int r = mc->build_initial_monmap();
     if (r == -EINVAL)
       usage();
     if (r < 0)
@@ -127,7 +170,7 @@ int main(int argc, const char **argv, const char *envp[]) {
     messenger->set_policy(entity_name_t::TYPE_MDS,
                          Messenger::Policy::lossless_client(0, 0));
 
-    client = new Client(messenger, &mc);
+    client = new Client(messenger, mc);
     if (filer_flags) {
       client->set_filer_flags(filer_flags);
     }
@@ -169,17 +212,24 @@ int main(int argc, const char **argv, const char *envp[]) {
       cerr << "ceph-fuse[" << getpid() << "]: fuse failed to start" << std::endl;
       goto out_client_unmount;
     }
+
     cerr << "ceph-fuse[" << getpid() << "]: starting fuse" << std::endl;
+    tester.init(cfuse, client);
+    tester.create();
     r = cfuse->loop();
-    cerr << "ceph-fuse[" << getpid() << "]: fuse finished with error " << r << std::endl;
-
+    tester.join(&tester_rp);
+    tester_r = static_cast<int>(reinterpret_cast<uint64_t>(tester_rp));
+    cerr << "ceph-fuse[" << getpid() << "]: fuse finished with error " << r
+        << " and tester_r " << tester_r <<std::endl;
+    
+    
   out_client_unmount:
     client->unmount();
     //cout << "unmounted" << std::endl;
-
+    
     cfuse->finalize();
     delete cfuse;
-
+    
   out_shutdown:
     client->shutdown();
   out_init_failed:
@@ -189,17 +239,19 @@ int main(int argc, const char **argv, const char *envp[]) {
   out_messenger_start_failed:
     delete client;
   out_mc_start_failed:
-
+    
     if (g_conf->daemonize) {
       //cout << "child signalling parent with " << r << std::endl;
       static int foo = 0;
       foo += ::write(fd[1], &r, sizeof(r));
     }
-
+    
     delete messenger;
     g_ceph_context->put();
     free(newargv);
-
+    
+    delete mc;
+    
     //cout << "child done" << std::endl;
     return r;
   } else {