Fixed AIO on Linux, broken in r4306.

Events from eventfd do not have c->write set, and the stale event
check added in r4306 causes null pointer dereference.

diff --git a/src/event/modules/ngx_epoll_module.c b/src/event/modules/ngx_epoll_module.c
index 4f9c5118e7f492fdba10e213b3dd336cb9813287..f4003af70359b4a32c589c7b58de1b49c5fe3dd8 100644 (file)
--- a/src/event/modules/ngx_epoll_module.c
+++ b/src/event/modules/ngx_epoll_module.c
@@ -681,19 +681,19 @@ ngx_epoll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags)
 
         wev = c->write;
 
-        if (c->fd == -1 || wev->instance != instance) {
+        if ((revents & EPOLLOUT) && wev->active) {
 
-            /*
-             * the stale event from a file descriptor
-             * that was just closed in this iteration
-             */
+            if (c->fd == -1 || wev->instance != instance) {
 
-            ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
-                           "epoll: stale event %p", c);
-            continue;
-        }
+                /*
+                 * the stale event from a file descriptor
+                 * that was just closed in this iteration
+                 */
 
-        if ((revents & EPOLLOUT) && wev->active) {
+                ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                               "epoll: stale event %p", c);
+                continue;
+            }
 
             if (flags & NGX_POST_THREAD_EVENTS) {
                 wev->posted_ready = 1;