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 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/messenger.c b/net/ceph/messenger.c
index b9796750034a..24c5eea8c45b 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 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)