This patch will lookup existing nodes instead of always creating them when dlm_midcomms_addr() is called. The idea is here to create midcomms nodes when user space getting informed that nodes joins the cluster. This is the case when dlm_midcomms_addr() is called, however it can be called multiple times by user space to add several address configurations to one node e.g. when using SCTP. Those multiple times need to be filtered out and we doing that by looking up if the node exists before. Due configfs entry it is safe that this function gets only called once at a time.
Cc: stable@vger.kernel.org Fixes: 63e711b08160 ("fs: dlm: create midcomms nodes when configure") Signed-off-by: Alexander Aring aahringo@redhat.com --- fs/dlm/midcomms.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/dlm/midcomms.c b/fs/dlm/midcomms.c index f641b36a36db..455265c6ba53 100644 --- a/fs/dlm/midcomms.c +++ b/fs/dlm/midcomms.c @@ -337,13 +337,21 @@ static struct midcomms_node *nodeid2node(int nodeid)
int dlm_midcomms_addr(int nodeid, struct sockaddr_storage *addr, int len) { - int ret, r = nodeid_hash(nodeid); + int ret, idx, r = nodeid_hash(nodeid); struct midcomms_node *node;
ret = dlm_lowcomms_addr(nodeid, addr, len); if (ret) return ret;
+ idx = srcu_read_lock(&nodes_srcu); + node = __find_node(nodeid, r); + if (node) { + srcu_read_unlock(&nodes_srcu, idx); + return 0; + } + srcu_read_unlock(&nodes_srcu, idx); + node = kmalloc(sizeof(*node), GFP_NOFS); if (!node) return -ENOMEM;