dlm: don't save callbacks after accept

When DLM calls accept() on a socket, the comm code copies the sk
after we've saved its callbacks. Afterward, it calls add_sock which
saves the callbacks a second time. Since the error reporting function
lowcomms_error_report calls the previous callback too, this results
in a recursive call to itself. This patch adds a new parameter to
function add_sock to tell whether to save the callbacks. Function
tcp_accept_from_sock (and its sctp counterpart) then calls it with
false to avoid the recursion.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 609998de533e894d9cb98f3ff7ef3e05b41d424a..485494e5a28e411e8296c38651e3ee3433f21b38 100644 (file)
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -541,7 +541,7 @@ static void restore_callbacks(struct connection *con, struct sock *sk)
 }
 
 /* Make a socket active */
-static void add_sock(struct socket *sock, struct connection *con)
+static void add_sock(struct socket *sock, struct connection *con, bool save_cb)
 {
        struct sock *sk = sock->sk;
 
@@ -549,7 +549,7 @@ static void add_sock(struct socket *sock, struct connection *con)
        con->sock = sock;
 
        sk->sk_user_data = con;
-       if (!test_bit(CF_IS_OTHERCON, &con->flags))
+       if (save_cb)
                save_callbacks(con, sk);
        /* Install a data_ready callback */
        sk->sk_data_ready = lowcomms_data_ready;
@@ -806,7 +806,7 @@ static int tcp_accept_from_sock(struct connection *con)
                        newcon->othercon = othercon;
                        othercon->sock = newsock;
                        newsock->sk->sk_user_data = othercon;
-                       add_sock(newsock, othercon);
+                       add_sock(newsock, othercon, false);
                        addcon = othercon;
                }
                else {
@@ -819,7 +819,10 @@ static int tcp_accept_from_sock(struct connection *con)
        else {
                newsock->sk->sk_user_data = newcon;
                newcon->rx_action = receive_from_sock;
-               add_sock(newsock, newcon);
+               /* accept copies the sk after we've saved the callbacks, so we
+                  don't want to save them a second time or comm errors will
+                  result in calling sk_error_report recursively. */
+               add_sock(newsock, newcon, false);
                addcon = newcon;
        }
 
@@ -919,7 +922,7 @@ static int sctp_accept_from_sock(struct connection *con)
                        newcon->othercon = othercon;
                        othercon->sock = newsock;
                        newsock->sk->sk_user_data = othercon;
-                       add_sock(newsock, othercon);
+                       add_sock(newsock, othercon, false);
                        addcon = othercon;
                } else {
                        printk("Extra connection from node %d attempted\n", nodeid);
@@ -930,7 +933,7 @@ static int sctp_accept_from_sock(struct connection *con)
        } else {
                newsock->sk->sk_user_data = newcon;
                newcon->rx_action = receive_from_sock;
-               add_sock(newsock, newcon);
+               add_sock(newsock, newcon, false);
                addcon = newcon;
        }
 
@@ -1058,7 +1061,7 @@ static void sctp_connect_to_sock(struct connection *con)
        sock->sk->sk_user_data = con;
        con->rx_action = receive_from_sock;
        con->connect_action = sctp_connect_to_sock;
-       add_sock(sock, con);
+       add_sock(sock, con, true);
 
        /* Bind to all addresses. */
        if (sctp_bind_addrs(con, 0))
@@ -1146,7 +1149,7 @@ static void tcp_connect_to_sock(struct connection *con)
        sock->sk->sk_user_data = con;
        con->rx_action = receive_from_sock;
        con->connect_action = tcp_connect_to_sock;
-       add_sock(sock, con);
+       add_sock(sock, con, true);
 
        /* Bind to our cluster-known address connecting to avoid
           routing problems */
@@ -1366,7 +1369,7 @@ static int tcp_listen_for_all(void)
 
        sock = tcp_create_listen_sock(con, dlm_local_addr[0]);
        if (sock) {
-               add_sock(sock, con);
+               add_sock(sock, con, true);
                result = 0;
        }
        else {