Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

Pull ceph fixes from Sage Weil:
 "Jim's fix closes a narrow race introduced with the msgr changes.  One
  fix resolves problems with debugfs initialization that Yan found when
  multiple client instances are created (e.g., two clusters mounted, or
  rbd + cephfs), another one fixes problems with mounting a nonexistent
  server subdirectory, and the last one fixes a divide by zero error
  from unsanitized ioctl input that Dan Carpenter found."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: avoid divide by zero in __validate_layout()
  libceph: avoid truncation due to racing banners
  ceph: tolerate (and warn on) extraneous dentry from mds
  libceph: delay debugfs initialization until we learn global_id

4 files changed, 59 insertions, 8 deletions

diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index 69e38db..a802029 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 54b531a..38b5dc1 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/messenger.c b/net/ceph/messenger.c
index b979675..24c5eea 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -915,7 +915,6 @@ static int prepare_write_connect(struct ceph_connection *con)
 	con->out_connect.authorizer_len = auth ?
 		cpu_to_le32(auth->authorizer_buf_len) : 0;
 
-	con_out_kvec_reset(con);
 	con_out_kvec_add(con, sizeof (con->out_connect),
 					&con->out_connect);
 	if (auth && auth->authorizer_buf_len)
@@ -1557,6 +1556,7 @@ static int process_connect(struct ceph_connection *con)
 			return -1;
 		}
 		con->auth_retry = 1;
+		con_out_kvec_reset(con);
 		ret = prepare_write_connect(con);
 		if (ret < 0)
 			return ret;
@@ -1577,6 +1577,7 @@ static int process_connect(struct ceph_connection *con)
 		       ENTITY_NAME(con->peer_name),
 		       ceph_pr_addr(&con->peer_addr.in_addr));
 		reset_connection(con);
+		con_out_kvec_reset(con);
 		ret = prepare_write_connect(con);
 		if (ret < 0)
 			return ret;
@@ -1601,6 +1602,7 @@ static int process_connect(struct ceph_connection *con)
 		     le32_to_cpu(con->out_connect.connect_seq),
 		     le32_to_cpu(con->in_reply.connect_seq));
 		con->connect_seq = le32_to_cpu(con->in_reply.connect_seq);
+		con_out_kvec_reset(con);
 		ret = prepare_write_connect(con);
 		if (ret < 0)
 			return ret;
@@ -1617,6 +1619,7 @@ static int process_connect(struct ceph_connection *con)
 		     le32_to_cpu(con->in_reply.global_seq));
 		get_global_seq(con->msgr,
 			       le32_to_cpu(con->in_reply.global_seq));
+		con_out_kvec_reset(con);
 		ret = prepare_write_connect(con);
 		if (ret < 0)
 			return ret;
@@ -2135,7 +2138,11 @@ more:
 		BUG_ON(con->state != CON_STATE_CONNECTING);
 		con->state = CON_STATE_NEGOTIATING;
 
-		/* Banner is good, exchange connection info */
+		/*
+		 * Received banner is good, exchange connection info.
+		 * Do not reset out_kvec, as sending our banner raced
+		 * with receiving peer banner after connect completed.
+		 */
 		ret = prepare_write_connect(con);
 		if (ret < 0)
 			goto out;
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 105d533..900ea0f 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)