mirror of https://github.com/hak5/openwrt-owl.git
117 lines
3.4 KiB
Diff
117 lines
3.4 KiB
Diff
From: Alexander Duyck <alexander.h.duyck@redhat.com>
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Date: Thu, 22 Jan 2015 15:51:45 -0800
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Subject: [PATCH] fib_trie: Various clean-ups for handling slen
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While doing further work on the fib_trie I noted a few items.
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First I was using calls that were far more complicated than they needed to
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be for determining when to push/pull the suffix length. I have updated the
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code to reflect the simplier logic.
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The second issue is that I realised we weren't necessarily handling the
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case of a leaf_info struct surviving a flush. I have updated the logic so
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that now we will call pull_suffix in the event of having a leaf info value
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left in the leaf after flushing it.
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Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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---
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--- a/net/ipv4/fib_trie.c
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+++ b/net/ipv4/fib_trie.c
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@@ -917,27 +917,20 @@ static void leaf_push_suffix(struct tnod
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static void remove_leaf_info(struct tnode *l, struct leaf_info *old)
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{
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- struct hlist_node *prev;
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-
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- /* record the location of the pointer to this object */
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- prev = rtnl_dereference(hlist_pprev_rcu(&old->hlist));
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+ /* record the location of the previous list_info entry */
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+ struct hlist_node **pprev = old->hlist.pprev;
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+ struct leaf_info *li = hlist_entry(pprev, typeof(*li), hlist.next);
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/* remove the leaf info from the list */
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hlist_del_rcu(&old->hlist);
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- /* if we emptied the list this leaf will be freed and we can sort
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- * out parent suffix lengths as a part of trie_rebalance
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- */
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- if (hlist_empty(&l->list))
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+ /* only access li if it is pointing at the last valid hlist_node */
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+ if (hlist_empty(&l->list) || (*pprev))
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return;
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- /* if we removed the tail then we need to update slen */
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- if (!rcu_access_pointer(hlist_next_rcu(prev))) {
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- struct leaf_info *li = hlist_entry(prev, typeof(*li), hlist);
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-
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- l->slen = KEYLENGTH - li->plen;
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- leaf_pull_suffix(l);
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- }
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+ /* update the trie with the latest suffix length */
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+ l->slen = KEYLENGTH - li->plen;
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+ leaf_pull_suffix(l);
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}
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static void insert_leaf_info(struct tnode *l, struct leaf_info *new)
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@@ -961,7 +954,7 @@ static void insert_leaf_info(struct tnod
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}
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/* if we added to the tail node then we need to update slen */
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- if (!rcu_access_pointer(hlist_next_rcu(&new->hlist))) {
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+ if (l->slen < (KEYLENGTH - new->plen)) {
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l->slen = KEYLENGTH - new->plen;
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leaf_push_suffix(l);
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}
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@@ -1613,6 +1606,7 @@ static int trie_flush_leaf(struct tnode
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struct hlist_head *lih = &l->list;
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struct hlist_node *tmp;
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struct leaf_info *li = NULL;
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+ unsigned char plen = KEYLENGTH;
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hlist_for_each_entry_safe(li, tmp, lih, hlist) {
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found += trie_flush_list(&li->falh);
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@@ -1620,8 +1614,14 @@ static int trie_flush_leaf(struct tnode
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if (list_empty(&li->falh)) {
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hlist_del_rcu(&li->hlist);
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free_leaf_info(li);
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+ continue;
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}
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+
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+ plen = li->plen;
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}
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+
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+ l->slen = KEYLENGTH - plen;
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+
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return found;
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}
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@@ -1700,13 +1700,22 @@ int fib_table_flush(struct fib_table *tb
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for (l = trie_firstleaf(t); l; l = trie_nextleaf(l)) {
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found += trie_flush_leaf(l);
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- if (ll && hlist_empty(&ll->list))
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- trie_leaf_remove(t, ll);
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+ if (ll) {
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+ if (hlist_empty(&ll->list))
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+ trie_leaf_remove(t, ll);
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+ else
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+ leaf_pull_suffix(ll);
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+ }
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+
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ll = l;
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}
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- if (ll && hlist_empty(&ll->list))
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- trie_leaf_remove(t, ll);
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+ if (ll) {
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+ if (hlist_empty(&ll->list))
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+ trie_leaf_remove(t, ll);
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+ else
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+ leaf_pull_suffix(ll);
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+ }
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pr_debug("trie_flush found=%d\n", found);
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return found;
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