net: dev: Improve debug statements for adjacency tracking
Adjacency code only has debugs for the insert case. Add debugs for
the remove path and make both consistently worded to make it easier
to follow the insert and removal with reference counts.
In addition, change the BUG to a WARN_ON. A missing adjacency at
removal time is not cause for a panic.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index c6bbf31..f55fb45 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5561,6 +5561,9 @@
if (adj) {
adj->ref_nr += 1;
+ pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
+ dev->name, adj_dev->name, adj->ref_nr);
+
return 0;
}
@@ -5574,8 +5577,8 @@
adj->private = private;
dev_hold(adj_dev);
- pr_debug("dev_hold for %s, because of link added from %s to %s\n",
- adj_dev->name, dev->name, adj_dev->name);
+ pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
+ dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
@@ -5614,17 +5617,22 @@
{
struct netdev_adjacent *adj;
+ pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
+ dev->name, adj_dev->name, ref_nr);
+
adj = __netdev_find_adj(adj_dev, dev_list);
if (!adj) {
- pr_err("tried to remove device %s from %s\n",
+ pr_err("Adjacency does not exist for device %s from %s\n",
dev->name, adj_dev->name);
- BUG();
+ WARN_ON(1);
+ return;
}
if (adj->ref_nr > ref_nr) {
- pr_debug("%s to %s ref_nr-%d = %d\n", dev->name, adj_dev->name,
- ref_nr, adj->ref_nr-ref_nr);
+ pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
+ dev->name, adj_dev->name, ref_nr,
+ adj->ref_nr - ref_nr);
adj->ref_nr -= ref_nr;
return;
}
@@ -5636,7 +5644,7 @@
netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
list_del_rcu(&adj->list);
- pr_debug("dev_put for %s, because link removed from %s to %s\n",
+ pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
adj_dev->name, dev->name, adj_dev->name);
dev_put(adj_dev);
kfree_rcu(adj, rcu);