[Cluster-devel] [PATCH dlm/next 3/3] fs: dlm: check on existing node address

[Alexander Aring <aahringo@redhat.com>]

This patch checks if we add twice the same address to a per node address
array. This should never be the case and we report -EEXIST to the user
space.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
 fs/dlm/lowcomms.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index c23d794e82910..0dc651676dfa1 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -370,10 +370,28 @@ static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid)
 	return rv;
 }
 
+static bool dlm_lowcomms_na_has_addr(const struct dlm_node_addr *na,
+				     const struct sockaddr_storage *addr)
+{
+	int i;
+
+	spin_lock(&dlm_node_addrs_spin);
+	for (i = 0; i < na->addr_count; i++) {
+		if (addr_compare(na->addr[i], addr)) {
+			spin_unlock(&dlm_node_addrs_spin);
+			return true;
+		}
+	}
+	spin_unlock(&dlm_node_addrs_spin);
+
+	return false;
+}
+
 int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len)
 {
 	struct sockaddr_storage *new_addr;
 	struct dlm_node_addr *new_node, *na;
+	bool ret;
 
 	new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS);
 	if (!new_node)
@@ -398,6 +416,14 @@ int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len)
 		return 0;
 	}
 
+	ret = dlm_lowcomms_na_has_addr(na, addr);
+	if (ret) {
+		spin_unlock(&dlm_node_addrs_spin);
+		kfree(new_addr);
+		kfree(new_node);
+		return -EEXIST;
+	}
+
 	if (na->addr_count >= DLM_MAX_ADDR_COUNT) {
 		spin_unlock(&dlm_node_addrs_spin);
 		kfree(new_addr);
-- 
2.26.2