libceph: delay debugfs initialization until we learn global_id

The debugfs directory includes the cluster fsid and our unique global_id.
We need to delay the initialization of the debug entry until we have
learned both the fsid and our global_id from the monitor or else the
second client can't create its debugfs entry and will fail (and multiple
client instances aren't properly reflected in debugfs).

Reported by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

4 files changed, 51 insertions, 6 deletions

diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c
index fb962efdacee..6d59006bfa27 100644
--- a/fs/ceph/debugfs.c
+++ b/fs/ceph/debugfs.c
@@ -201,6 +201,7 @@ int ceph_fs_debugfs_init(struct ceph_fs_client *fsc)
         int err = -ENOMEM;
 
         dout("ceph_fs_debugfs_init\n");
+        BUG_ON(!fsc->client->debugfs_dir);
         fsc->debugfs_congestion_kb =
                 debugfs_create_file("writeback_congestion_kb",
                                     0600,
diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index 69e38db28e5f..a8020293f342 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -84,7 +84,6 @@ int ceph_check_fsid(struct ceph_client *client, struct ceph_fsid *fsid)
                         return -1;
                 }
         } else {
-                pr_info("client%lld fsid %pU\n", ceph_client_id(client), fsid);
                 memcpy(&client->fsid, fsid, sizeof(*fsid));
         }
         return 0;
diff --git a/net/ceph/debugfs.c b/net/ceph/debugfs.c
index 54b531a01121..38b5dc1823d4 100644
--- a/net/ceph/debugfs.c
+++ b/net/ceph/debugfs.c
@@ -189,6 +189,9 @@ int ceph_debugfs_client_init(struct ceph_client *client)
         snprintf(name, sizeof(name), "%pU.client%lld", &client->fsid,
                  client->monc.auth->global_id);
 
+        dout("ceph_debugfs_client_init %p %s\n", client, name);
+
+        BUG_ON(client->debugfs_dir);
         client->debugfs_dir = debugfs_create_dir(name, ceph_debugfs_dir);
         if (!client->debugfs_dir)
                 goto out;
@@ -234,6 +237,7 @@ out:
 
 void ceph_debugfs_client_cleanup(struct ceph_client *client)
 {
+        dout("ceph_debugfs_client_cleanup %p\n", client);
         debugfs_remove(client->debugfs_osdmap);
         debugfs_remove(client->debugfs_monmap);
         debugfs_remove(client->osdc.debugfs_file);
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 105d533b55f3..900ea0f043fc 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -311,6 +311,17 @@ int ceph_monc_open_session(struct ceph_mon_client *monc)
 EXPORT_SYMBOL(ceph_monc_open_session);
 
 /*
+ * We require the fsid and global_id in order to initialize our
+ * debugfs dir.
+ */
+static bool have_debugfs_info(struct ceph_mon_client *monc)
+{
+        dout("have_debugfs_info fsid %d globalid %lld\n",
+             (int)monc->client->have_fsid, monc->auth->global_id);
+        return monc->client->have_fsid && monc->auth->global_id > 0;
+}
+
+/*
  * The monitor responds with mount ack indicate mount success.  The
  * included client ticket allows the client to talk to MDSs and OSDs.
  */
@@ -320,9 +331,12 @@ static void ceph_monc_handle_map(struct ceph_mon_client *monc,
         struct ceph_client *client = monc->client;
         struct ceph_monmap *monmap = NULL, *old = monc->monmap;
         void *p, *end;
+        int had_debugfs_info, init_debugfs = 0;
 
         mutex_lock(&monc->mutex);
 
+        had_debugfs_info = have_debugfs_info(monc);
+
         dout("handle_monmap\n");
         p = msg->front.iov_base;
         end = p + msg->front.iov_len;
@@ -344,12 +358,22 @@ static void ceph_monc_handle_map(struct ceph_mon_client *monc,
 
         if (!client->have_fsid) {
                 client->have_fsid = true;
+                if (!had_debugfs_info && have_debugfs_info(monc)) {
+                        pr_info("client%lld fsid %pU\n",
+                                ceph_client_id(monc->client),
+                                &monc->client->fsid);
+                        init_debugfs = 1;
+                }
                 mutex_unlock(&monc->mutex);
-                /*
-                 * do debugfs initialization without mutex to avoid
-                 * creating a locking dependency
-                 */
-                ceph_debugfs_client_init(client);
+
+                if (init_debugfs) {
+                        /*
+                         * do debugfs initialization without mutex to avoid
+                         * creating a locking dependency
+                         */
+                        ceph_debugfs_client_init(monc->client);
+                }
+
                 goto out_unlocked;
         }
 out:
@@ -865,8 +889,10 @@ static void handle_auth_reply(struct ceph_mon_client *monc,
 {
         int ret;
         int was_auth = 0;
+        int had_debugfs_info, init_debugfs = 0;
 
         mutex_lock(&monc->mutex);
+        had_debugfs_info = have_debugfs_info(monc);
         if (monc->auth->ops)
                 was_auth = monc->auth->ops->is_authenticated(monc->auth);
         monc->pending_auth = 0;
@@ -889,7 +915,22 @@ static void handle_auth_reply(struct ceph_mon_client *monc,
                 __send_subscribe(monc);
                 __resend_generic_request(monc);
         }
+
+        if (!had_debugfs_info && have_debugfs_info(monc)) {
+                pr_info("client%lld fsid %pU\n",
+                        ceph_client_id(monc->client),
+                        &monc->client->fsid);
+                init_debugfs = 1;
+        }
         mutex_unlock(&monc->mutex);
+
+        if (init_debugfs) {
+                /*
+                 * do debugfs initialization without mutex to avoid
+                 * creating a locking dependency
+                 */
+                ceph_debugfs_client_init(monc->client);
+        }
 }
 
 static int __validate_auth(struct ceph_mon_client *monc)