fs: dlm: check on existing node address

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

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 7f85594..372c34f 100644 (file)
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -374,10 +374,25 @@ unlock:
        return rv;
 }
 
+/* caller need to held dlm_node_addrs_spin lock */
+static bool dlm_lowcomms_na_has_addr(const struct dlm_node_addr *na,
+                                    const struct sockaddr_storage *addr)
+{
+       int i;
+
+       for (i = 0; i < na->addr_count; i++) {
+               if (addr_compare(na->addr[i], addr))
+                       return true;
+       }
+
+       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)
@@ -402,6 +417,14 @@ 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);