libceph: protect ceph_con_open() with mutex

(cherry picked from commit 5469155f2bc83bb2c88b0a0370c3d54d87eed06e)

Take the con mutex while we are initiating a ceph open.  This is necessary
because the may have previously been in use and then closed, which could
result in a racing workqueue running con_work().

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index c5df88364f271e8142f9f3a2a23cf115bb1e8331..b59e64a7b24bfb22bbe1f5f70a8fcfb4c79e9b09 100644 (file)
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -537,6 +537,7 @@ void ceph_con_open(struct ceph_connection *con,
                   __u8 entity_type, __u64 entity_num,
                   struct ceph_entity_addr *addr)
 {
+       mutex_lock(&con->mutex);
        dout("con_open %p %s\n", con, ceph_pr_addr(&addr->in_addr));
        set_bit(OPENING, &con->state);
        WARN_ON(!test_and_clear_bit(CLOSED, &con->state));
@@ -546,6 +547,7 @@ void ceph_con_open(struct ceph_connection *con,
 
        memcpy(&con->peer_addr, addr, sizeof(*addr));
        con->delay = 0;      /* reset backoff memory */
+       mutex_unlock(&con->mutex);
        queue_con(con);
 }
 EXPORT_SYMBOL(ceph_con_open);