[IPV4] fib_trie: Document locking.

Paul E. McKenney writes:

> Those of use who dive into networking only occasionally would much
> appreciate this.  ;-)

No problem here... 

Acked-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> (but trivial)
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index ada9b3db507d..214c34732e84 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1123,6 +1123,9 @@ err:
         return fa_head;
 }
 
+/*
+ * Caller must hold RTNL.
+ */
 static int fn_trie_insert(struct fib_table *tb, struct fib_config *cfg)
 {
         struct trie *t = (struct trie *) tb->tb_data;
@@ -1540,6 +1543,9 @@ static int trie_leaf_remove(struct trie *t, t_key key)
         return 1;
 }
 
+/*
+ * Caller must hold RTNL.
+ */
 static int fn_trie_delete(struct fib_table *tb, struct fib_config *cfg)
 {
         struct trie *t = (struct trie *) tb->tb_data;
@@ -1718,6 +1724,9 @@ up:
         return NULL; /* Ready. Root of trie */
 }
 
+/*
+ * Caller must hold RTNL.
+ */
 static int fn_trie_flush(struct fib_table *tb)
 {
         struct trie *t = (struct trie *) tb->tb_data;