Cache: keep c->body_start when Vary changes (ticket #2029).

If the variant hash doesn't match one we used as a secondary cache key,
we switch back to the original key.  In this case, c->body_start was kept
updated from an existing cache node overwriting the new response value.
After file cache update, it led to discrepancy between a cache node and
cache file seen as critical errors "file cache .. has too long header".
This commit is contained in:
Sergey Kandaurov 2020-09-09 19:26:27 +03:00
parent ed0b19cdd4
commit dc1b14126e
2 changed files with 3 additions and 1 deletions

View File

@ -117,6 +117,7 @@ struct ngx_http_cache_s {
unsigned purged:1;
unsigned reading:1;
unsigned secondary:1;
unsigned update_variant:1;
unsigned background:1;
unsigned stale_updating:1;

View File

@ -854,7 +854,7 @@ ngx_http_file_cache_exists(ngx_http_file_cache_t *cache, ngx_http_cache_t *c)
if (fcn->exists || fcn->uses >= c->min_uses) {
c->exists = fcn->exists;
if (fcn->body_start) {
if (fcn->body_start && !c->update_variant) {
c->body_start = fcn->body_start;
}
@ -1339,6 +1339,7 @@ ngx_http_file_cache_update_variant(ngx_http_request_t *r, ngx_http_cache_t *c)
ngx_shmtx_unlock(&cache->shpool->mutex);
c->file.name.len = 0;
c->update_variant = 1;
ngx_memcpy(c->key, c->main, NGX_HTTP_CACHE_KEY_LEN);