Tue, Nov 15, 2016 at 11:46:06AM CET, alexander.h.du...@intel.com wrote:
>The patch that removed the FIB offload infrastructure was a bit too
>aggressive and also removed code needed to clean up us splitting the table
>if additional rules were added. Specifically the function
>fib_trie_flush_external was called at the end of a new rule being added to
>flush the foreign trie entries from the main trie.
>
>I updated the code so that we only call fib_trie_flush_external on the main
>table so that we flush the entries for local from main. This way we don't
>call it for every rule change which is what was happening previously.
Well, the function was introduced by:
commit 104616e74e0b464d449fdd2ee2f547d2fad71610
Author: Scott Feldman <sfel...@gmail.com>
Date: Thu Mar 5 21:21:16 2015 -0800
switchdev: don't support custom ip rules, for now
Keep switchdev FIB offload model simple for now and don't allow custom ip
rules.
Why this was not needed before? What changed in between:
104616e74e0b464d449fdd2ee2f547d2fad71610 ("switchdev: don't support custom ip
rules, for now")
and
347e3b28c1ba2 ("switchdev: remove FIB offload infrastructure")
?
>
>Fixes: 347e3b28c1ba2 ("switchdev: remove FIB offload infrastructure")
>Reported-by: Eric Dumazet <eduma...@google.com>
>Cc: Jiri Pirko <j...@mellanox.com>
>Signed-off-by: Alexander Duyck <alexander.h.du...@intel.com>
>---
> include/net/ip_fib.h | 1 +
> net/ipv4/fib_frontend.c | 20 +++++++++++---
> net/ipv4/fib_trie.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 81 insertions(+), 5 deletions(-)
>
>diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
>index b9314b4..f390c3b 100644
>--- a/include/net/ip_fib.h
>+++ b/include/net/ip_fib.h
>@@ -243,6 +243,7 @@ int fib_table_dump(struct fib_table *table, struct sk_buff
>*skb,
> struct netlink_callback *cb);
> int fib_table_flush(struct net *net, struct fib_table *table);
> struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
>+void fib_table_flush_external(struct fib_table *table);
> void fib_free_table(struct fib_table *tb);
>
> #ifndef CONFIG_IP_MULTIPLE_TABLES
>diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
>index c3b8047..161fc0f 100644
>--- a/net/ipv4/fib_frontend.c
>+++ b/net/ipv4/fib_frontend.c
>@@ -151,7 +151,7 @@ static void fib_replace_table(struct net *net, struct
>fib_table *old,
>
> int fib_unmerge(struct net *net)
> {
>- struct fib_table *old, *new;
>+ struct fib_table *old, *new, *main_table;
>
> /* attempt to fetch local table if it has been allocated */
> old = fib_get_table(net, RT_TABLE_LOCAL);
>@@ -162,11 +162,21 @@ int fib_unmerge(struct net *net)
> if (!new)
> return -ENOMEM;
>
>+ /* table is already unmerged */
>+ if (new == old)
>+ return 0;
>+
> /* replace merged table with clean table */
>- if (new != old) {
>- fib_replace_table(net, old, new);
>- fib_free_table(old);
>- }
>+ fib_replace_table(net, old, new);
>+ fib_free_table(old);
>+
>+ /* attempt to fetch main table if it has been allocated */
>+ main_table = fib_get_table(net, RT_TABLE_MAIN);
>+ if (!main_table)
>+ return 0;
>+
>+ /* flush local entries from main table */
>+ fib_table_flush_external(main_table);
>
> return 0;
> }
>diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
>index 4cff74d..735edc9 100644
>--- a/net/ipv4/fib_trie.c
>+++ b/net/ipv4/fib_trie.c
>@@ -1760,6 +1760,71 @@ struct fib_table *fib_trie_unmerge(struct fib_table
>*oldtb)
> return NULL;
> }
>
>+/* Caller must hold RTNL */
>+void fib_table_flush_external(struct fib_table *tb)
>+{
>+ struct trie *t = (struct trie *)tb->tb_data;
>+ struct key_vector *pn = t->kv;
>+ unsigned long cindex = 1;
>+ struct hlist_node *tmp;
>+ struct fib_alias *fa;
>+
>+ /* walk trie in reverse order */
>+ for (;;) {
>+ unsigned char slen = 0;
>+ struct key_vector *n;
>+
>+ if (!(cindex--)) {
>+ t_key pkey = pn->key;
>+
>+ /* cannot resize the trie vector */
>+ if (IS_TRIE(pn))
>+ break;
>+
>+ /* resize completed node */
>+ pn = resize(t, pn);
>+ cindex = get_index(pkey, pn);
>+
>+ continue;
>+ }
>+
>+ /* grab the next available node */
>+ n = get_child(pn, cindex);
>+ if (!n)
>+ continue;
>+
>+ if (IS_TNODE(n)) {
>+ /* record pn and cindex for leaf walking */
>+ pn = n;
>+ cindex = 1ul << n->bits;
>+
>+ continue;
>+ }
>+
>+ hlist_for_each_entry_safe(fa, tmp, &n->leaf, fa_list) {
>+ /* if alias was cloned to local then we just
>+ * need to remove the local copy from main
>+ */
>+ if (tb->tb_id != fa->tb_id) {
>+ hlist_del_rcu(&fa->fa_list);
>+ alias_free_mem_rcu(fa);
>+ continue;
>+ }
>+
>+ /* record local slen */
>+ slen = fa->fa_slen;
>+ }
>+
>+ /* update leaf slen */
>+ n->slen = slen;
>+
>+ if (hlist_empty(&n->leaf)) {
>+ put_child_root(pn, n->key, NULL);
>+ node_free(n);
>+ }
>+ }
>+}
>+
> /* Caller must hold RTNL. */
> int fib_table_flush(struct net *net, struct fib_table *tb)
> {
>
