several changes in cache cleanup handling:

*) now ngx_http_file_cache_cleanup() uses ngx_http_file_cache_free()
*) ngx_http_file_cache_free() interface has been changed to accept r->cache
   ngx_http_file_cache_cleanup() must use r->cache, but not r, because
   there can be several r->cache's during request processing, r->cache may
   be NULL at request finalising, etc.
*) test if updating request does not complete correctly

src/http/ngx_http_cache.h

@@ -78,6 +78,7 @@ struct ngx_http_cache_s {
     ngx_http_file_cache_node_t      *node;
 
     unsigned                         updated:1;
+    unsigned                         updating:1;
     unsigned                         exists:1;
     unsigned                         temp_file:1;
 };
@@ -129,7 +130,7 @@ ngx_int_t ngx_http_file_cache_open(ngx_http_request_t *r);
 void ngx_http_file_cache_set_header(ngx_http_request_t *r, u_char *buf);
 void ngx_http_file_cache_update(ngx_http_request_t *r, ngx_temp_file_t *tf);
 ngx_int_t ngx_http_cache_send(ngx_http_request_t *);
-void ngx_http_file_cache_free(ngx_http_request_t *r, ngx_temp_file_t *tf);
+void ngx_http_file_cache_free(ngx_http_cache_t *c, ngx_temp_file_t *tf);
 time_t ngx_http_file_cache_valid(ngx_array_t *cache_valid, ngx_uint_t status);
 
 char *ngx_http_file_cache_set_slot(ngx_conf_t *cf, ngx_command_t *cmd,

src/http/ngx_http_file_cache.c

@@ -430,6 +430,7 @@ ngx_http_file_cache_read(ngx_http_request_t *r, ngx_http_cache_t *c)
 
         } else {
             c->node->updating = 1;
+            c->updating = 1;
             rc = NGX_HTTP_CACHE_STALE;
         }
 
@@ -793,6 +794,7 @@ ngx_http_file_cache_update(ngx_http_request_t *r, ngx_temp_file_t *tf)
                    "http file cache update");
 
     c->updated = 1;
+    c->updating = 0;
 
     cache = c->file_cache;
 
@@ -902,30 +904,28 @@ ngx_http_cache_send(ngx_http_request_t *r)
 
 
 void
-ngx_http_file_cache_free(ngx_http_request_t *r, ngx_temp_file_t *tf)
+ngx_http_file_cache_free(ngx_http_cache_t *c, ngx_temp_file_t *tf)
 {
-    ngx_http_cache_t            *c;
     ngx_http_file_cache_t       *cache;
     ngx_http_file_cache_node_t  *fcn;
 
-    c = r->cache;
-
     if (c->updated) {
         return;
     }
 
-    c->updated = 1;
-
     cache = c->file_cache;
 
-    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->file.log, 0,
                    "http file cache free");
 
     ngx_shmtx_lock(&cache->shpool->mutex);
 
     fcn = c->node;
     fcn->count--;
-    fcn->updating = 0;
+
+    if (c->updating) {
+        fcn->updating = 0;
+    }
 
     if (c->error) {
         fcn->valid_sec = c->valid_sec;
@@ -941,14 +941,17 @@ ngx_http_file_cache_free(ngx_http_request_t *r, ngx_temp_file_t *tf)
 
     ngx_shmtx_unlock(&cache->shpool->mutex);
 
+    c->updated = 1;
+    c->updating = 0;
+
     if (c->temp_file) {
         if (tf && tf->file.fd != NGX_INVALID_FILE) {
-            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->file.log, 0,
                            "http file cache incomplete: \"%s\"",
                            tf->file.name.data);
 
             if (ngx_delete_file(tf->file.name.data) == NGX_FILE_ERROR) {
-                ngx_log_error(NGX_LOG_CRIT, r->connection->log, ngx_errno,
+                ngx_log_error(NGX_LOG_CRIT, c->file.log, ngx_errno,
                               ngx_delete_file_n " \"%s\" failed",
                               tf->file.name.data);
             }
@@ -962,28 +965,19 @@ ngx_http_file_cache_cleanup(void *data)
 {
     ngx_http_cache_t  *c = data;
 
-    ngx_http_file_cache_t  *cache;
-
     if (c->updated) {
         return;
     }
 
-    c->updated = 1;
-
     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->file.log, 0,
                    "http file cache cleanup");
 
-    if (c->error) {
+    if (c->updating) {
-        return;
+        ngx_log_error(NGX_LOG_ALERT, c->file.log, 0,
+                      "stalled cache updating, error:%ui", c->error);
     }
 
-    cache = c->file_cache;
+    ngx_http_file_cache_free(c, NULL);
-
-    ngx_shmtx_lock(&cache->shpool->mutex);
-
-    c->node->count--;
-
-    ngx_shmtx_unlock(&cache->shpool->mutex);
 }
 
 

src/http/ngx_http_upstream.c

@@ -1735,7 +1735,7 @@ ngx_http_upstream_intercept_errors(ngx_http_request_t *r,
                     r->cache->error = status;
                 }
 
-                ngx_http_file_cache_free(r, u->pipe->temp_file);
+                ngx_http_file_cache_free(r->cache, u->pipe->temp_file);
             }
 #endif
             ngx_http_upstream_finalize_request(r, u, status);
@@ -2189,7 +2189,7 @@ ngx_http_upstream_send_response(ngx_http_request_t *r, ngx_http_upstream_t *u)
                    "http cacheable: %d", u->cacheable);
 
     if (u->cacheable == 0 && r->cache) {
-        ngx_http_file_cache_free(r, u->pipe->temp_file);
+        ngx_http_file_cache_free(r->cache, u->pipe->temp_file);
     }
 
 #endif
@@ -2664,7 +2664,7 @@ ngx_http_upstream_process_request(ngx_http_request_t *r)
                 ngx_http_file_cache_update(r, u->pipe->temp_file);
 
             } else if (p->upstream_error) {
-                ngx_http_file_cache_free(r, u->pipe->temp_file);
+                ngx_http_file_cache_free(r->cache, u->pipe->temp_file);
             }
         }
 
@@ -3005,7 +3005,7 @@ ngx_http_upstream_finalize_request(ngx_http_request_t *r,
             }
         }
 
-        ngx_http_file_cache_free(r, u->pipe->temp_file);
+        ngx_http_file_cache_free(r->cache, u->pipe->temp_file);
     }
 
 #endif