diff options
| -rw-r--r-- | nest/route.h | 6 | ||||
| -rw-r--r-- | nest/rt-show.c | 9 | ||||
| -rw-r--r-- | nest/rt-table.c | 82 |
3 files changed, 95 insertions, 2 deletions
diff --git a/nest/route.h b/nest/route.h index c4e0d2c6..7930058a 100644 --- a/nest/route.h +++ b/nest/route.h @@ -191,6 +191,9 @@ typedef struct rtable { struct fib_iterator prune_fit; /* Rtable prune FIB iterator */ struct fib_iterator nhu_fit; /* Next Hop Update FIB iterator */ struct f_trie *trie_new; /* New prefix trie defined during pruning */ + struct f_trie *trie_old; /* Old prefix trie waiting to be freed */ + u32 trie_lock_count; /* Prefix trie locked by walks */ + u32 trie_old_lock_count; /* Old prefix trie locked by walks */ list subscribers; /* Subscribers for notifications */ struct timer *settle_timer; /* Settle time for notifications */ @@ -332,6 +335,8 @@ void rt_preconfig(struct config *); void rt_commit(struct config *new, struct config *old); void rt_lock_table(rtable *); void rt_unlock_table(rtable *); +struct f_trie * rt_lock_trie(rtable *tab); +void rt_unlock_trie(rtable *tab, struct f_trie *trie); void rt_subscribe(rtable *tab, struct rt_subscription *s); void rt_unsubscribe(struct rt_subscription *s); void rt_flowspec_link(rtable *src, rtable *dst); @@ -405,6 +410,7 @@ struct rt_show_data { struct rt_show_data_rtable *last_table; /* Last table in output */ struct fib_iterator fit; /* Iterator over networks in table */ struct f_trie_walk_state *walk_state; /* Iterator over networks in trie */ + struct f_trie *walk_lock; /* Locked trie for walking */ int verbose, tables_defined_by; const struct filter *filter; struct proto *show_protocol; diff --git a/nest/rt-show.c b/nest/rt-show.c index ea1f918c..f8b7ba51 100644 --- a/nest/rt-show.c +++ b/nest/rt-show.c @@ -222,6 +222,9 @@ rt_show_cleanup(struct cli *c) if (d->table_open && !d->trie_walk) fit_get(&d->tab->table->fib, &d->fit); + if (d->walk_lock) + rt_unlock_trie(d->tab->table, d->walk_lock); + /* Unlock referenced tables */ WALK_LIST(tab, d->tables) rt_unlock_table(tab->table); @@ -257,7 +260,10 @@ rt_show_cont(struct cli *c) d->walk_state = lp_allocz(c->parser_pool, sizeof (struct f_trie_walk_state)); if (d->trie_walk) + { + d->walk_lock = rt_lock_trie(tab); trie_walk_init(d->walk_state, tab->trie, d->addr); + } else FIB_ITERATE_INIT(&d->fit, &tab->fib); @@ -288,6 +294,9 @@ rt_show_cont(struct cli *c) if (!--max) return; } + + rt_unlock_trie(tab, d->walk_lock); + d->walk_lock = NULL; } else { diff --git a/nest/rt-table.c b/nest/rt-table.c index ac14aec9..a10979e6 100644 --- a/nest/rt-table.c +++ b/nest/rt-table.c @@ -2471,7 +2471,19 @@ again: if (tab->trie_new) { /* Finish prefix trie pruning */ - rfree(tab->trie->lp); + + if (!tab->trie_lock_count) + { + rfree(tab->trie->lp); + } + else + { + ASSERT(!tab->trie_old); + tab->trie_old = tab->trie; + tab->trie_old_lock_count = tab->trie_lock_count; + tab->trie_lock_count = 0; + } + tab->trie = tab->trie_new; tab->trie_new = NULL; tab->prune_trie = 0; @@ -2479,7 +2491,7 @@ again: else { /* Schedule prefix trie pruning */ - if (tab->trie && (tab->trie->prefix_count > (2 * tab->fib.entries))) + if (tab->trie && !tab->trie_old && (tab->trie->prefix_count > (2 * tab->fib.entries))) { /* state change 0->1, 2->3 */ tab->prune_state |= 1; @@ -2504,6 +2516,72 @@ again: return; } +/** + * rt_lock_trie - lock a prefix trie of a routing table + * @tab: routing table with prefix trie to be locked + * + * The prune loop may rebuild the prefix trie and invalidate f_trie_walk_state + * structures. Therefore, asynchronous walks should lock the prefix trie using + * this function. That allows the prune loop to rebuild the trie, but postpones + * its freeing until all walks are done (unlocked by rt_unlock_trie()). + * + * Return a current trie that will be locked, the value should be passed back to + * rt_unlock_trie() for unlocking. + * + */ +struct f_trie * +rt_lock_trie(rtable *tab) +{ + ASSERT(tab->trie); + + tab->trie_lock_count++; + return tab->trie; +} + +/** + * rt_unlock_trie - unlock a prefix trie of a routing table + * @tab: routing table with prefix trie to be locked + * @trie: value returned by matching rt_lock_trie() + * + * Done for trie locked by rt_lock_trie() after walk over the trie is done. + * It may free the trie and schedule next trie pruning. + */ +void +rt_unlock_trie(rtable *tab, struct f_trie *trie) +{ + ASSERT(trie); + + if (trie == tab->trie) + { + /* Unlock the current prefix trie */ + ASSERT(tab->trie_lock_count); + tab->trie_lock_count--; + } + else if (trie == tab->trie_old) + { + /* Unlock the old prefix trie */ + ASSERT(tab->trie_old_lock_count); + tab->trie_old_lock_count--; + + /* Free old prefix trie that is no longer needed */ + if (!tab->trie_old_lock_count) + { + rfree(tab->trie_old->lp); + tab->trie_old = NULL; + + /* Kick prefix trie pruning that was postponed */ + if (tab->trie && (tab->trie->prefix_count > (2 * tab->fib.entries))) + { + tab->prune_trie = 1; + rt_schedule_prune(tab); + } + } + } + else + log(L_BUG "Invalid arg to rt_unlock_trie()"); +} + + void rt_preconfig(struct config *c) { |