From c9bd34c7e0b0b4845d058c67c55fb0600a339919 Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Fri, 22 Dec 2017 17:42:46 +0100 Subject: [PATCH] BUG/MEDIUM: cache: replace old object on store Currently the cache aborts a store operation if the object to store already exists in the cache. This is used to avoid storing multiple copies at the same time on concurrent accesses. It causes an issue though, which is that existing unexpired objects cannot be updated. This happens when any request criterion disables the retrieval from the cache (eg: with max-age or any other cache-control condition). For now, let's simply replace the previous existing entry by unlinking it from the index. This could possibly be improved in the future if needed. This fix needs to be backported to 1.8. --- src/cache.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/src/cache.c b/src/cache.c index 371ce20ac..351276e4d 100644 --- a/src/cache.c +++ b/src/cache.c @@ -469,6 +469,7 @@ enum act_return http_action_store_cache(struct act_rule *rule, struct proxy *px, filter->config->conf == rule->arg.act.p[0]) { if (filter->ctx) { struct cache_st *cache_ctx = filter->ctx; + struct cache_entry *old; cache_ctx->first_block = first; object = (struct cache_entry *)first->data; @@ -478,14 +479,11 @@ enum act_return http_action_store_cache(struct act_rule *rule, struct proxy *px, /* Insert the node later on caching success */ shctx_lock(shctx); - if (entry_exist(cache, txn->cache_hash)) { - shctx_unlock(shctx); - if (filter->ctx) { - object->eb.key = 0; - pool_free(pool_head_cache_st, filter->ctx); - filter->ctx = NULL; - } - goto out; + + old = entry_exist(cache, txn->cache_hash); + if (old) { + eb32_delete(&old->eb); + old->eb.key = 0; } shctx_unlock(shctx);