Fixed premature background subrequest finalization.

When "aio" or "aio threads" is used while processing the response body of an
in-memory background subrequest, the subrequest could be finalized with an aio
operation still in progress.  Upon aio completion either parent request is
woken or the old r->write_event_handler is called again.  The latter may result
in request errors.  In either case post_subrequest handler is never called with
the full response body, which is typically expected when using in-memory
subrequests.

Currently in nginx background subrequests are created by the upstream module
and the mirror module.  The issue does not manifest itself with these
subrequests because they are header-only.  But it can manifest itself with
third-party modules which create in-memory background subrequests.
This commit is contained in:
Dmitry Volyntsev 2020-03-02 20:07:36 +03:00
parent 6ba18bc35e
commit 3733c6fd70

View File

@ -2490,6 +2490,15 @@ ngx_http_finalize_request(ngx_http_request_t *r, ngx_int_t rc)
if (r != r->main) {
clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
if (r->buffered || r->postponed) {
if (ngx_http_set_write_handler(r) != NGX_OK) {
ngx_http_terminate_request(r, 0);
}
return;
}
if (r->background) {
if (!r->logged) {
if (clcf->log_subrequest) {
@ -2509,15 +2518,6 @@ ngx_http_finalize_request(ngx_http_request_t *r, ngx_int_t rc)
return;
}
if (r->buffered || r->postponed) {
if (ngx_http_set_write_handler(r) != NGX_OK) {
ngx_http_terminate_request(r, 0);
}
return;
}
pr = r->parent;
if (r == c->data) {