Changes with nginx 1.7.6 30 Sep 2014v1.7.6

    *) Change: the deprecated "limit_zone" directive is not supported
       anymore.

    *) Feature: the "limit_conn_zone" and "limit_req_zone" directives now
       can be used with combinations of multiple variables.

    *) Bugfix: request body might be transmitted incorrectly when retrying a
       FastCGI request to the next upstream server.

    *) Bugfix: in logging to syslog.

20 files changed, 297 insertions, 604 deletions

diff --git a/CHANGES b/CHANGES
index ac1fac018..ddfb80014 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,18 @@
 
+Changes with nginx 1.7.6                                         30 Sep 2014
+
+    *) Change: the deprecated "limit_zone" directive is not supported
+       anymore.
+
+    *) Feature: the "limit_conn_zone" and "limit_req_zone" directives now
+       can be used with combinations of multiple variables.
+
+    *) Bugfix: request body might be transmitted incorrectly when retrying a
+       FastCGI request to the next upstream server.
+
+    *) Bugfix: in logging to syslog.
+
+
 Changes with nginx 1.7.5                                         16 Sep 2014
 
     *) Security: it was possible to reuse SSL sessions in unrelated contexts
diff --git a/CHANGES.ru b/CHANGES.ru
index dcdab4e0a..4eff3ccf9 100644
--- a/CHANGES.ru
+++ b/CHANGES.ru
@@ -1,4 +1,17 @@
 
+Изменения в nginx 1.7.6                                           30.09.2014
+
+    *) Изменение: устаревшая директива limit_zone больше не поддерживается.
+
+    *) Добавление: в директивах limit_conn_zone и limit_req_zone теперь
+       можно использовать комбинации нескольких переменных.
+
+    *) Исправление: при повторной отправке FastCGI-запроса на бэкенд тело
+       запроса могло передаваться неправильно.
+
+    *) Исправление: в логгировании в syslog.
+
+
 Изменения в nginx 1.7.5                                           16.09.2014
 
     *) Безопасность: при использовании общего для нескольких блоков server
diff --git a/src/core/nginx.h b/src/core/nginx.h
index 4524e005e..3030b44b4 100644
--- a/src/core/nginx.h
+++ b/src/core/nginx.h
@@ -9,8 +9,8 @@
 #define _NGINX_H_INCLUDED_
 
 
-#define nginx_version      1007005
-#define NGINX_VERSION      "1.7.5"
+#define nginx_version      1007006
+#define NGINX_VERSION      "1.7.6"
 #define NGINX_VER          "nginx/" NGINX_VERSION
 
 #ifdef NGX_BUILD
diff --git a/src/core/ngx_buf.c b/src/core/ngx_buf.c
index 835c76ced..94a3d3f10 100644
--- a/src/core/ngx_buf.c
+++ b/src/core/ngx_buf.c
@@ -218,3 +218,49 @@ ngx_chain_update_chains(ngx_pool_t *p, ngx_chain_t **free, ngx_chain_t **busy,
         *free = cl;
     }
 }
+
+
+ngx_chain_t *
+ngx_handle_sent_chain(ngx_chain_t *in, off_t sent)
+{
+    off_t  size;
+
+    for ( /* void */ ; in; in = in->next) {
+
+        if (ngx_buf_special(in->buf)) {
+            continue;
+        }
+
+        if (sent == 0) {
+            break;
+        }
+
+        size = ngx_buf_size(in->buf);
+
+        if (sent >= size) {
+            sent -= size;
+
+            if (ngx_buf_in_memory(in->buf)) {
+                in->buf->pos = in->buf->last;
+            }
+
+            if (in->buf->in_file) {
+                in->buf->file_pos = in->buf->file_last;
+            }
+
+            continue;
+        }
+
+        if (ngx_buf_in_memory(in->buf)) {
+            in->buf->pos += (size_t) sent;
+        }
+
+        if (in->buf->in_file) {
+            in->buf->file_pos += sent;
+        }
+
+        break;
+    }
+
+    return in;
+}
diff --git a/src/core/ngx_buf.h b/src/core/ngx_buf.h
index ffc531094..cc28a3e15 100644
--- a/src/core/ngx_buf.h
+++ b/src/core/ngx_buf.h
@@ -158,5 +158,6 @@ ngx_chain_t *ngx_chain_get_free_buf(ngx_pool_t *p, ngx_chain_t **free);
 void ngx_chain_update_chains(ngx_pool_t *p, ngx_chain_t **free,
     ngx_chain_t **busy, ngx_chain_t **out, ngx_buf_tag_t tag);
 
+ngx_chain_t *ngx_handle_sent_chain(ngx_chain_t *in, off_t sent);
 
 #endif /* _NGX_BUF_H_INCLUDED_ */
diff --git a/src/core/ngx_syslog.c b/src/core/ngx_syslog.c
index e6d40f48a..616fd712e 100644
--- a/src/core/ngx_syslog.c
+++ b/src/core/ngx_syslog.c
@@ -234,11 +234,11 @@ ngx_syslog_writer(ngx_log_t *log, ngx_uint_t level, u_char *buf,
 
     peer = log->wdata;
 
-    if (peer->processing) {
+    if (peer->busy) {
         return;
     }
 
-    peer->processing = 1;
+    peer->busy = 1;
     peer->severity = level - 1;
 
     p = ngx_syslog_add_header(peer, msg);
@@ -254,26 +254,47 @@ ngx_syslog_writer(ngx_log_t *log, ngx_uint_t level, u_char *buf,
 
     (void) ngx_syslog_send(peer, msg, p - msg);
 
-    peer->processing = 0;
+    peer->busy = 0;
 }
 
 
 ssize_t
 ngx_syslog_send(ngx_syslog_peer_t *peer, u_char *buf, size_t len)
 {
+    ssize_t  n;
+
     if (peer->conn.fd == (ngx_socket_t) -1) {
         if (ngx_syslog_init_peer(peer) != NGX_OK) {
             return NGX_ERROR;
         }
     }
 
+    /* log syslog socket events with valid log */
+    peer->conn.log = ngx_cycle->log;
+
     if (ngx_send) {
-        return ngx_send(&peer->conn, buf, len);
+        n = ngx_send(&peer->conn, buf, len);
 
     } else {
         /* event module has not yet set ngx_io */
-        return ngx_os_io.send(&peer->conn, buf, len);
+        n = ngx_os_io.send(&peer->conn, buf, len);
+    }
+
+#if (NGX_HAVE_UNIX_DOMAIN)
+
+    if (n == NGX_ERROR && peer->server.sockaddr->sa_family == AF_UNIX) {
+
+        if (ngx_close_socket(peer->conn.fd) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_socket_errno,
+                          ngx_close_socket_n " failed");
+        }
+
+        peer->conn.fd = (ngx_socket_t) -1;
     }
+
+#endif
+
+    return n;
 }
 
 
@@ -285,7 +306,6 @@ ngx_syslog_init_peer(ngx_syslog_peer_t *peer)
 
     peer->conn.read = &ngx_syslog_dummy_event;
     peer->conn.write = &ngx_syslog_dummy_event;
-    peer->conn.log = &ngx_syslog_dummy_log;
 
     ngx_syslog_dummy_event.log = &ngx_syslog_dummy_log;
 
@@ -339,6 +359,13 @@ ngx_syslog_cleanup(void *data)
 {
     ngx_syslog_peer_t  *peer = data;
 
+    /* prevents further use of this peer */
+    peer->busy = 1;
+
+    if (peer->conn.fd == (ngx_socket_t) -1) {
+        return;
+    }
+
     if (ngx_close_socket(peer->conn.fd) == -1) {
         ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_socket_errno,
                       ngx_close_socket_n " failed");
diff --git a/src/core/ngx_syslog.h b/src/core/ngx_syslog.h
index 92d47d5f5..a9150516f 100644
--- a/src/core/ngx_syslog.h
+++ b/src/core/ngx_syslog.h
@@ -16,7 +16,7 @@ typedef struct {
 
     ngx_addr_t        server;
     ngx_connection_t  conn;
-    ngx_uint_t        processing;  /* unsigned processing:1; */
+    ngx_uint_t        busy;  /* unsigned busy:1; */
 } ngx_syslog_peer_t;
 
 
diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index 9847ec170..a49c93ca2 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -1129,6 +1129,7 @@ ngx_http_fastcgi_create_request(ngx_http_request_t *r)
 
                 } else {
                     b->pos = pos;
+                    b->start = pos;
                     pos += 32 * 1024;
 
                     if (pos >= body->buf->last) {
diff --git a/src/http/modules/ngx_http_limit_conn_module.c b/src/http/modules/ngx_http_limit_conn_module.c
index 7f0eea7ab..4379311ca 100644
--- a/src/http/modules/ngx_http_limit_conn_module.c
+++ b/src/http/modules/ngx_http_limit_conn_module.c
@@ -11,41 +11,40 @@
 
 
 typedef struct {
-    u_char              color;
-    u_char              len;
-    u_short             conn;
-    u_char              data[1];
+    u_char                     color;
+    u_char                     len;
+    u_short                    conn;
+    u_char                     data[1];
 } ngx_http_limit_conn_node_t;
 
 
 typedef struct {
-    ngx_shm_zone_t     *shm_zone;
-    ngx_rbtree_node_t  *node;
+    ngx_shm_zone_t            *shm_zone;
+    ngx_rbtree_node_t         *node;
 } ngx_http_limit_conn_cleanup_t;
 
 
 typedef struct {
-    ngx_rbtree_t       *rbtree;
-    ngx_int_t           index;
-    ngx_str_t           var;
+    ngx_rbtree_t              *rbtree;
+    ngx_http_complex_value_t   key;
 } ngx_http_limit_conn_ctx_t;
 
 
 typedef struct {
-    ngx_shm_zone_t     *shm_zone;
-    ngx_uint_t          conn;
+    ngx_shm_zone_t            *shm_zone;
+    ngx_uint_t                 conn;
 } ngx_http_limit_conn_limit_t;
 
 
 typedef struct {
-    ngx_array_t         limits;
-    ngx_uint_t          log_level;
-    ngx_uint_t          status_code;
+    ngx_array_t                limits;
+    ngx_uint_t                 log_level;
+    ngx_uint_t                 status_code;
 } ngx_http_limit_conn_conf_t;
 
 
 static ngx_rbtree_node_t *ngx_http_limit_conn_lookup(ngx_rbtree_t *rbtree,
-    ngx_http_variable_value_t *vv, uint32_t hash);
+    ngx_str_t *key, uint32_t hash);
 static void ngx_http_limit_conn_cleanup(void *data);
 static ngx_inline void ngx_http_limit_conn_cleanup_all(ngx_pool_t *pool);
 
@@ -54,18 +53,11 @@ static char *ngx_http_limit_conn_merge_conf(ngx_conf_t *cf, void *parent,
     void *child);
 static char *ngx_http_limit_conn_zone(ngx_conf_t *cf, ngx_command_t *cmd,
     void *conf);
-static char *ngx_http_limit_zone(ngx_conf_t *cf, ngx_command_t *cmd,
-    void *conf);
 static char *ngx_http_limit_conn(ngx_conf_t *cf, ngx_command_t *cmd,
     void *conf);
 static ngx_int_t ngx_http_limit_conn_init(ngx_conf_t *cf);
 
 
-static ngx_conf_deprecated_t  ngx_conf_deprecated_limit_zone = {
-    ngx_conf_deprecated, "limit_zone", "limit_conn_zone"
-};
-
-
 static ngx_conf_enum_t  ngx_http_limit_conn_log_levels[] = {
     { ngx_string("info"), NGX_LOG_INFO },
     { ngx_string("notice"), NGX_LOG_NOTICE },
@@ -89,13 +81,6 @@ static ngx_command_t  ngx_http_limit_conn_commands[] = {
       0,
       NULL },
 
-    { ngx_string("limit_zone"),
-      NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE3,
-      ngx_http_limit_zone,
-      0,
-      0,
-      NULL },
-
     { ngx_string("limit_conn"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2,
       ngx_http_limit_conn,
@@ -155,13 +140,13 @@ ngx_module_t  ngx_http_limit_conn_module = {
 static ngx_int_t
 ngx_http_limit_conn_handler(ngx_http_request_t *r)
 {
-    size_t                          len, n;
+    size_t                          n;
     uint32_t                        hash;
+    ngx_str_t                       key;
     ngx_uint_t                      i;
     ngx_slab_pool_t                *shpool;
     ngx_rbtree_node_t              *node;
     ngx_pool_cleanup_t             *cln;
-    ngx_http_variable_value_t      *vv;
     ngx_http_limit_conn_ctx_t      *ctx;
     ngx_http_limit_conn_node_t     *lc;
     ngx_http_limit_conn_conf_t     *lccf;
@@ -178,41 +163,37 @@ ngx_http_limit_conn_handler(ngx_http_request_t *r)
     for (i = 0; i < lccf->limits.nelts; i++) {
         ctx = limits[i].shm_zone->data;
 
-        vv = ngx_http_get_indexed_variable(r, ctx->index);
-
-        if (vv == NULL || vv->not_found) {
-            continue;
+        if (ngx_http_complex_value(r, &ctx->key, &key) != NGX_OK) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
         }
 
-        len = vv->len;
-
-        if (len == 0) {
+        if (key.len == 0) {
             continue;
         }
 
-        if (len > 255) {
+        if (key.len > 255) {
             ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
-                          "the value of the \"%V\" variable "
-                          "is more than 255 bytes: \"%v\"",
-                          &ctx->var, vv);
+                          "the value of the \"%V\" key "
+                          "is more than 255 bytes: \"%V\"",
+                          &ctx->key.value, &key);
             continue;
         }
 
         r->main->limit_conn_set = 1;
 
-        hash = ngx_crc32_short(vv->data, len);
+        hash = ngx_crc32_short(key.data, key.len);
 
         shpool = (ngx_slab_pool_t *) limits[i].shm_zone->shm.addr;
 
         ngx_shmtx_lock(&shpool->mutex);
 
-        node = ngx_http_limit_conn_lookup(ctx->rbtree, vv, hash);
+        node = ngx_http_limit_conn_lookup(ctx->rbtree, &key, hash);
 
         if (node == NULL) {
 
             n = offsetof(ngx_rbtree_node_t, color)
                 + offsetof(ngx_http_limit_conn_node_t, data)
-                + len;
+                + key.len;
 
             node = ngx_slab_alloc_locked(shpool, n);
 
@@ -225,9 +206,9 @@ ngx_http_limit_conn_handler(ngx_http_request_t *r)
             lc = (ngx_http_limit_conn_node_t *) &node->color;
 
             node->key = hash;
-            lc->len = (u_char) len;
+            lc->len = (u_char) key.len;
             lc->conn = 1;
-            ngx_memcpy(lc->data, vv->data, len);
+            ngx_memcpy(lc->data, key.data, key.len);
 
             ngx_rbtree_insert(ctx->rbtree, node);
 
@@ -314,8 +295,7 @@ ngx_http_limit_conn_rbtree_insert_value(ngx_rbtree_node_t *temp,
 
 
 static ngx_rbtree_node_t *
-ngx_http_limit_conn_lookup(ngx_rbtree_t *rbtree, ngx_http_variable_value_t *vv,
-    uint32_t hash)
+ngx_http_limit_conn_lookup(ngx_rbtree_t *rbtree, ngx_str_t *key, uint32_t hash)
 {
     ngx_int_t                    rc;
     ngx_rbtree_node_t           *node, *sentinel;
@@ -340,8 +320,8 @@ ngx_http_limit_conn_lookup(ngx_rbtree_t *rbtree, ngx_http_variable_value_t *vv,
 
         lcn = (ngx_http_limit_conn_node_t *) &node->color;
 
-        rc = ngx_memn2cmp(vv->data, lcn->data,
-                          (size_t) vv->len, (size_t) lcn->len);
+        rc = ngx_memn2cmp(key->data, lcn->data, key->len, (size_t) lcn->len);
+
         if (rc == 0) {
             return node;
         }
@@ -413,11 +393,16 @@ ngx_http_limit_conn_init_zone(ngx_shm_zone_t *shm_zone, void *data)
     ctx = shm_zone->data;
 
     if (octx) {
-        if (ngx_strcmp(ctx->var.data, octx->var.data) != 0) {
+        if (ctx->key.value.len != octx->key.value.len
+            || ngx_strncmp(ctx->key.value.data, octx->key.value.data,
+                           ctx->key.value.len)
+               != 0)
+        {
             ngx_log_error(NGX_LOG_EMERG, shm_zone->shm.log, 0,
-                          "limit_conn_zone \"%V\" uses the \"%V\" variable "
-                          "while previously it used the \"%V\" variable",
-                          &shm_zone->shm.name, &ctx->var, &octx->var);
+                          "limit_conn_zone \"%V\" uses the \"%V\" key "
+                          "while previously it used the \"%V\" key",
+                          &shm_zone->shm.name, &ctx->key.value,
+                          &octx->key.value);
             return NGX_ERROR;
         }
 
@@ -507,20 +492,35 @@ ngx_http_limit_conn_merge_conf(ngx_conf_t *cf, void *parent, void *child)
 static char *
 ngx_http_limit_conn_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 {
-    u_char                     *p;
-    ssize_t                     size;
-    ngx_str_t                  *value, name, s;
-    ngx_uint_t                  i;
-    ngx_shm_zone_t             *shm_zone;
-    ngx_http_limit_conn_ctx_t  *ctx;
+    u_char                            *p;
+    ssize_t                            size;
+    ngx_str_t                         *value, name, s;
+    ngx_uint_t                         i;
+    ngx_shm_zone_t                    *shm_zone;
+    ngx_http_limit_conn_ctx_t         *ctx;
+    ngx_http_compile_complex_value_t   ccv;
 
     value = cf->args->elts;
 
-    ctx = NULL;
+    ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_limit_conn_ctx_t));
+    if (ctx == NULL) {
+        return NGX_CONF_ERROR;
+    }
+
+    ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));
+
+    ccv.cf = cf;
+    ccv.value = &value[1];
+    ccv.complex_value = &ctx->key;
+
+    if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
+        return NGX_CONF_ERROR;
+    }
+
     size = 0;
     name.len = 0;
 
-    for (i = 1; i < cf->args->nelts; i++) {
+    for (i = 2; i < cf->args->nelts; i++) {
 
         if (ngx_strncmp(value[i].data, "zone=", 5) == 0) {
 
@@ -556,26 +556,6 @@ ngx_http_limit_conn_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
             continue;
         }
 
-        if (value[i].data[0] == '$') {
-
-            value[i].len--;
-            value[i].data++;
-
-            ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_limit_conn_ctx_t));
-            if (ctx == NULL) {
-                return NGX_CONF_ERROR;
-            }
-
-            ctx->index = ngx_http_get_variable_index(cf, &value[i]);
-            if (ctx->index == NGX_ERROR) {
-                return NGX_CONF_ERROR;
-            }
-
-            ctx->var = value[i];
-
-            continue;
-        }
-
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                            "invalid parameter \"%V\"", &value[i]);
         return NGX_CONF_ERROR;
@@ -588,13 +568,6 @@ ngx_http_limit_conn_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         return NGX_CONF_ERROR;
     }
 
-    if (ctx == NULL) {
-        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "no variable is defined for %V \"%V\"",
-                           &cmd->name, &name);
-        return NGX_CONF_ERROR;
-    }
-
     shm_zone = ngx_shared_memory_add(cf, &name, size,
                                      &ngx_http_limit_conn_module);
     if (shm_zone == NULL) {
@@ -605,78 +578,8 @@ ngx_http_limit_conn_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         ctx = shm_zone->data;
 
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "%V \"%V\" is already bound to variable \"%V\"",
-                           &cmd->name, &name, &ctx->var);
-        return NGX_CONF_ERROR;
-    }
-
-    shm_zone->init = ngx_http_limit_conn_init_zone;
-    shm_zone->data = ctx;
-
-    return NGX_CONF_OK;
-}
-
-
-static char *
-ngx_http_limit_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
-{
-    ssize_t                     n;
-    ngx_str_t                  *value;
-    ngx_shm_zone_t             *shm_zone;
-    ngx_http_limit_conn_ctx_t  *ctx;
-
-    ngx_conf_deprecated(cf, &ngx_conf_deprecated_limit_zone, NULL);
-
-    value = cf->args->elts;
-
-    if (value[2].data[0] != '$') {
-        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "invalid variable name \"%V\"", &value[2]);
-        return NGX_CONF_ERROR;
-    }
-
-    value[2].len--;
-    value[2].data++;
-
-    ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_limit_conn_ctx_t));
-    if (ctx == NULL) {
-        return NGX_CONF_ERROR;
-    }
-
-    ctx->index = ngx_http_get_variable_index(cf, &value[2]);
-    if (ctx->index == NGX_ERROR) {
-        return NGX_CONF_ERROR;
-    }
-
-    ctx->var = value[2];
-
-    n = ngx_parse_size(&value[3]);
-
-    if (n == NGX_ERROR) {
-        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "invalid size of limit_zone \"%V\"", &value[3]);
-        return NGX_CONF_ERROR;
-    }
-
-    if (n < (ngx_int_t) (8 * ngx_pagesize)) {
-        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "limit_zone \"%V\" is too small", &value[1]);
-        return NGX_CONF_ERROR;
-    }
-
-
-    shm_zone = ngx_shared_memory_add(cf, &value[1], n,
-                                     &ngx_http_limit_conn_module);
-    if (shm_zone == NULL) {
-        return NGX_CONF_ERROR;
-    }
-
-    if (shm_zone->data) {
-        ctx = shm_zone->data;
-
-        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                        "limit_zone \"%V\" is already bound to variable \"%V\"",
-                        &value[1], &ctx->var);
+                           "%V \"%V\" is already bound to key \"%V\"",
+                           &cmd->name, &name, &ctx->key.value);
         return NGX_CONF_ERROR;
     }
 
diff --git a/src/http/modules/ngx_http_limit_req_module.c b/src/http/modules/ngx_http_limit_req_module.c
index 74f7fdaa7..5d5cbe944 100644
--- a/src/http/modules/ngx_http_limit_req_module.c
+++ b/src/http/modules/ngx_http_limit_req_module.c
@@ -35,8 +35,7 @@ typedef struct {
     ngx_slab_pool_t             *shpool;
     /* integer value, 1 corresponds to 0.001 r/s */
     ngx_uint_t                   rate;
-    ngx_int_t                    index;
-    ngx_str_t                    var;
+    ngx_http_complex_value_t     key;
     ngx_http_limit_req_node_t   *node;
 } ngx_http_limit_req_ctx_t;
 
@@ -59,8 +58,7 @@ typedef struct {
 
 static void ngx_http_limit_req_delay(ngx_http_request_t *r);
 static ngx_int_t ngx_http_limit_req_lookup(ngx_http_limit_req_limit_t *limit,
-    ngx_uint_t hash, u_char *data, size_t len, ngx_uint_t *ep,
-    ngx_uint_t account);
+    ngx_uint_t hash, ngx_str_t *key, ngx_uint_t *ep, ngx_uint_t account);
 static ngx_msec_t ngx_http_limit_req_account(ngx_http_limit_req_limit_t *limits,
     ngx_uint_t n, ngx_uint_t *ep, ngx_http_limit_req_limit_t **limit);
 static void ngx_http_limit_req_expire(ngx_http_limit_req_ctx_t *ctx,
@@ -158,12 +156,11 @@ ngx_module_t  ngx_http_limit_req_module = {
 static ngx_int_t
 ngx_http_limit_req_handler(ngx_http_request_t *r)
 {
-    size_t                       len;
     uint32_t                     hash;
+    ngx_str_t                    key;
     ngx_int_t                    rc;
     ngx_uint_t                   n, excess;
     ngx_msec_t                   delay;
-    ngx_http_variable_value_t   *vv;
     ngx_http_limit_req_ctx_t    *ctx;
     ngx_http_limit_req_conf_t   *lrcf;
     ngx_http_limit_req_limit_t  *limit, *limits;
@@ -189,31 +186,27 @@ ngx_http_limit_req_handler(ngx_http_request_t *r)
 
         ctx = limit->shm_zone->data;
 
-        vv = ngx_http_get_indexed_variable(r, ctx->index);
-
-        if (vv == NULL || vv->not_found) {
-            continue;
+        if (ngx_http_complex_value(r, &ctx->key, &key) != NGX_OK) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
         }
 
-        len = vv->len;
-
-        if (len == 0) {
+        if (key.len == 0) {
             continue;
         }
 
-        if (len > 65535) {
+        if (key.len > 65535) {
             ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
-                          "the value of the \"%V\" variable "
-                          "is more than 65535 bytes: \"%v\"",
-                          &ctx->var, vv);
+                          "the value of the \"%V\" key "
+                          "is more than 65535 bytes: \"%V\"",
+                          &ctx->key.value, &key);
             continue;
         }
 
-        hash = ngx_crc32_short(vv->data, len);
+        hash = ngx_crc32_short(key.data, key.len);
 
         ngx_shmtx_lock(&ctx->shpool->mutex);
 
-        rc = ngx_http_limit_req_lookup(limit, hash, vv->data, len, &excess,
+        rc = ngx_http_limit_req_lookup(limit, hash, &key, &excess,
                                        (n == lrcf->limits.nelts - 1));
 
         ngx_shmtx_unlock(&ctx->shpool->mutex);
@@ -365,7 +358,7 @@ ngx_http_limit_req_rbtree_insert_value(ngx_rbtree_node_t *temp,
 
 static ngx_int_t
 ngx_http_limit_req_lookup(ngx_http_limit_req_limit_t *limit, ngx_uint_t hash,
-    u_char *data, size_t len, ngx_uint_t *ep, ngx_uint_t account)
+    ngx_str_t *key, ngx_uint_t *ep, ngx_uint_t account)
 {
     size_t                      size;
     ngx_int_t                   rc, excess;
@@ -400,7 +393,7 @@ ngx_http_limit_req_lookup(ngx_http_limit_req_limit_t *limit, ngx_uint_t hash,
 
         lr = (ngx_http_limit_req_node_t *) &node->color;
 
-        rc = ngx_memn2cmp(data, lr->data, len, (size_t) lr->len);
+        rc = ngx_memn2cmp(key->data, lr->data, key->len, (size_t) lr->len);
 
         if (rc == 0) {
             ngx_queue_remove(&lr->queue);
@@ -440,7 +433,7 @@ ngx_http_limit_req_lookup(ngx_http_limit_req_limit_t *limit, ngx_uint_t hash,
 
     size = offsetof(ngx_rbtree_node_t, color)
            + offsetof(ngx_http_limit_req_node_t, data)
-           + len;
+           + key->len;
 
     ngx_http_limit_req_expire(ctx, 1);
 
@@ -461,10 +454,10 @@ ngx_http_limit_req_lookup(ngx_http_limit_req_limit_t *limit, ngx_uint_t hash,
 
     lr = (ngx_http_limit_req_node_t *) &node->color;
 
-    lr->len = (u_char) len;
+    lr->len = (u_short) key->len;
     lr->excess = 0;
 
-    ngx_memcpy(lr->data, data, len);
+    ngx_memcpy(lr->data, key->data, key->len);
 
     ngx_rbtree_insert(&ctx->sh->rbtree, node);
 
@@ -632,11 +625,16 @@ ngx_http_limit_req_init_zone(ngx_shm_zone_t *shm_zone, void *data)
     ctx = shm_zone->data;
 
     if (octx) {
-        if (ngx_strcmp(ctx->var.data, octx->var.data) != 0) {
+        if (ctx->key.value.len != octx->key.value.len
+            || ngx_strncmp(ctx->key.value.data, octx->key.value.data,
+                           ctx->key.value.len)
+               != 0)
+        {
             ngx_log_error(NGX_LOG_EMERG, shm_zone->shm.log, 0,
-                          "limit_req \"%V\" uses the \"%V\" variable "
-                          "while previously it used the \"%V\" variable",
-                          &shm_zone->shm.name, &ctx->var, &octx->var);
+                          "limit_req \"%V\" uses the \"%V\" key "
+                          "while previously it used the \"%V\" key",
+                          &shm_zone->shm.name, &ctx->key.value,
+                          &octx->key.value);
             return NGX_ERROR;
         }
 
@@ -731,24 +729,39 @@ ngx_http_limit_req_merge_conf(ngx_conf_t *cf, void *parent, void *child)
 static char *
 ngx_http_limit_req_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 {
-    u_char                    *p;
-    size_t                     len;
-    ssize_t                    size;
-    ngx_str_t                 *value, name, s;
-    ngx_int_t                  rate, scale;
-    ngx_uint_t                 i;
-    ngx_shm_zone_t            *shm_zone;
-    ngx_http_limit_req_ctx_t  *ctx;
+    u_char                            *p;
+    size_t                             len;
+    ssize_t                            size;
+    ngx_str_t                         *value, name, s;
+    ngx_int_t                          rate, scale;
+    ngx_uint_t                         i;
+    ngx_shm_zone_t                    *shm_zone;
+    ngx_http_limit_req_ctx_t          *ctx;
+    ngx_http_compile_complex_value_t   ccv;
 
     value = cf->args->elts;
 
-    ctx = NULL;
+    ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_limit_req_ctx_t));
+    if (ctx == NULL) {
+        return NGX_CONF_ERROR;
+    }
+
+    ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t));
+
+    ccv.cf = cf;
+    ccv.value = &value[1];
+    ccv.complex_value = &ctx->key;
+
+    if (ngx_http_compile_complex_value(&ccv) != NGX_OK) {
+        return NGX_CONF_ERROR;
+    }
+
     size = 0;
     rate = 1;
     scale = 1;
     name.len = 0;
 
-    for (i = 1; i < cf->args->nelts; i++) {
+    for (i = 2; i < cf->args->nelts; i++) {
 
         if (ngx_strncmp(value[i].data, "zone=", 5) == 0) {
 
@@ -808,26 +821,6 @@ ngx_http_limit_req_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
             continue;
         }
 
-        if (value[i].data[0] == '$') {
-
-            value[i].len--;
-            value[i].data++;
-
-            ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_limit_req_ctx_t));
-            if (ctx == NULL) {
-                return NGX_CONF_ERROR;
-            }
-
-            ctx->index = ngx_http_get_variable_index(cf, &value[i]);
-            if (ctx->index == NGX_ERROR) {
-                return NGX_CONF_ERROR;
-            }
-
-            ctx->var = value[i];
-
-            continue;
-        }
-
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                            "invalid parameter \"%V\"", &value[i]);
         return NGX_CONF_ERROR;
@@ -840,13 +833,6 @@ ngx_http_limit_req_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         return NGX_CONF_ERROR;
     }
 
-    if (ctx == NULL) {
-        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "no variable is defined for %V \"%V\"",
-                           &cmd->name, &name);
-        return NGX_CONF_ERROR;
-    }
-
     ctx->rate = rate * 1000 / scale;
 
     shm_zone = ngx_shared_memory_add(cf, &name, size,
@@ -859,8 +845,8 @@ ngx_http_limit_req_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         ctx = shm_zone->data;
 
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "%V \"%V\" is already bound to variable \"%V\"",
-                           &cmd->name, &name, &ctx->var);
+                           "%V \"%V\" is already bound to key \"%V\"",
+                           &cmd->name, &name, &ctx->key.value);
         return NGX_CONF_ERROR;
     }
 
diff --git a/src/http/modules/ngx_http_upstream_keepalive_module.c b/src/http/modules/ngx_http_upstream_keepalive_module.c
index c1c1c70d6..f738f0cc1 100644
--- a/src/http/modules/ngx_http_upstream_keepalive_module.c
+++ b/src/http/modules/ngx_http_upstream_keepalive_module.c
@@ -248,6 +248,7 @@ ngx_http_upstream_get_keepalive_peer(ngx_peer_connection_t *pc, void *data)
                            "get keepalive peer: using connection %p", c);
 
             c->idle = 0;
+            c->sent = 0;
             c->log = pc->log;
             c->read->log = pc->log;
             c->write->log = pc->log;
diff --git a/src/http/ngx_http.c b/src/http/ngx_http.c
index 31577f9a2..9c8d6cba4 100644
--- a/src/http/ngx_http.c
+++ b/src/http/ngx_http.c
@@ -2005,7 +2005,7 @@ ngx_http_types_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
             if (ngx_strcmp(value[i].data, type[n].key.data) == 0) {
                 ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                                    "duplicate MIME type \"%V\"", &value[i]);
-                continue;
+                goto next;
             }
         }
 
@@ -2017,6 +2017,10 @@ ngx_http_types_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         type->key = value[i];
         type->key_hash = hash;
         type->value = (void *) 4;
+
+    next:
+
+        continue;
     }
 
     return NGX_CONF_OK;
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 000c6de69..d547ca74e 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -1570,6 +1570,7 @@ done:
 static ngx_int_t
 ngx_http_upstream_reinit(ngx_http_request_t *r, ngx_http_upstream_t *u)
 {
+    off_t         file_pos;
     ngx_chain_t  *cl;
 
     if (u->reinit_request(r) != NGX_OK) {
@@ -1591,9 +1592,17 @@ ngx_http_upstream_reinit(ngx_http_request_t *r, ngx_http_upstream_t *u)
 
     /* reinit the request chain */
 
+    file_pos = 0;
+
     for (cl = u->request_bufs; cl; cl = cl->next) {
         cl->buf->pos = cl->buf->start;
-        cl->buf->file_pos = 0;
+
+        /* there is at most one file */
+
+        if (cl->buf->in_file) {
+            cl->buf->file_pos = file_pos;
+            file_pos = cl->buf->file_last;
+        }
     }
 
     /* reinit the subrequest's ngx_output_chain() context */
diff --git a/src/os/unix/ngx_darwin_sendfile_chain.c b/src/os/unix/ngx_darwin_sendfile_chain.c
index ee44e1d58..dd574e5ac 100644
--- a/src/os/unix/ngx_darwin_sendfile_chain.c
+++ b/src/os/unix/ngx_darwin_sendfile_chain.c
@@ -27,15 +27,6 @@
  */
 
 
-#if (IOV_MAX > 64)
-#define NGX_HEADERS   64
-#define NGX_TRAILERS  64
-#else
-#define NGX_HEADERS   IOV_MAX
-#define NGX_TRAILERS  IOV_MAX
-#endif
-
-
 ngx_chain_t *
 ngx_darwin_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 {
@@ -43,14 +34,16 @@ ngx_darwin_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
     u_char          *prev;
     off_t            size, send, prev_send, aligned, sent, fprev;
     off_t            header_size, file_size;
-    ngx_uint_t       eintr, complete;
+    ngx_uint_t       eintr;
     ngx_err_t        err;
     ngx_buf_t       *file;
     ngx_array_t      header, trailer;
     ngx_event_t     *wev;
     ngx_chain_t     *cl;
     struct sf_hdtr   hdtr;
-    struct iovec    *iov, headers[NGX_HEADERS], trailers[NGX_TRAILERS];
+    struct iovec    *iov;
+    struct iovec     headers[NGX_IOVS_PREALLOCATE];
+    struct iovec     trailers[NGX_IOVS_PREALLOCATE];
 
     wev = c->write;
 
@@ -79,12 +72,12 @@ ngx_darwin_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 
     header.elts = headers;
     header.size = sizeof(struct iovec);
-    header.nalloc = NGX_HEADERS;
+    header.nalloc = NGX_IOVS_PREALLOCATE;
     header.pool = c->pool;
 
     trailer.elts = trailers;
     trailer.size = sizeof(struct iovec);
-    trailer.nalloc = NGX_TRAILERS;
+    trailer.nalloc = NGX_IOVS_PREALLOCATE;
     trailer.pool = c->pool;
 
     for ( ;; ) {
@@ -92,7 +85,6 @@ ngx_darwin_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
         file_size = 0;
         header_size = 0;
         eintr = 0;
-        complete = 0;
         prev_send = send;
 
         header.nelts = 0;
@@ -285,7 +277,7 @@ ngx_darwin_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
             rc = writev(c->fd, header.elts, header.nelts);
 
             ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                           "writev: %d of %uz", rc, send);
+                           "writev: %d of %O", rc, header_size);
 
             if (rc == -1) {
                 err = ngx_errno;
@@ -311,54 +303,15 @@ ngx_darwin_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
             sent = rc > 0 ? rc : 0;
         }
 
-        if (send - prev_send == sent) {
-            complete = 1;
-        }
-
         c->sent += sent;
 
-        for ( /* void */ ; in; in = in->next) {
-
-            if (ngx_buf_special(in->buf)) {
-                continue;
-            }
-
-            if (sent == 0) {
-                break;
-            }
-
-            size = ngx_buf_size(in->buf);
-
-            if (sent >= size) {
-                sent -= size;
-
-                if (ngx_buf_in_memory(in->buf)) {
-                    in->buf->pos = in->buf->last;
-                }
-
-                if (in->buf->in_file) {
-                    in->buf->file_pos = in->buf->file_last;
-                }
-
-                continue;
-            }
-
-            if (ngx_buf_in_memory(in->buf)) {
-                in->buf->pos += (size_t) sent;
-            }
-
-            if (in->buf->in_file) {
-                in->buf->file_pos += sent;
-            }
-
-            break;
-        }
+        in = ngx_handle_sent_chain(in, sent);
 
         if (eintr) {
             continue;
         }
 
-        if (!complete) {
+        if (send - prev_send != sent) {
             wev->ready = 0;
             return in;
         }
diff --git a/src/os/unix/ngx_freebsd_sendfile_chain.c b/src/os/unix/ngx_freebsd_sendfile_chain.c
index 6491e928f..f5d0f3a8a 100644
--- a/src/os/unix/ngx_freebsd_sendfile_chain.c
+++ b/src/os/unix/ngx_freebsd_sendfile_chain.c
@@ -29,15 +29,6 @@
  */
 
 
-#if (IOV_MAX > 64)
-#define NGX_HEADERS   64
-#define NGX_TRAILERS  64
-#else
-#define NGX_HEADERS   IOV_MAX
-#define NGX_TRAILERS  IOV_MAX
-#endif
-
-
 ngx_chain_t *
 ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 {
@@ -45,14 +36,16 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
     u_char          *prev;
     off_t            size, send, prev_send, aligned, sent, fprev;
     size_t           header_size, file_size;
-    ngx_uint_t       eintr, eagain, complete;
+    ngx_uint_t       eintr, eagain;
     ngx_err_t        err;
     ngx_buf_t       *file;
     ngx_array_t      header, trailer;
     ngx_event_t     *wev;
     ngx_chain_t     *cl;
     struct sf_hdtr   hdtr;
-    struct iovec    *iov, headers[NGX_HEADERS], trailers[NGX_TRAILERS];
+    struct iovec    *iov;
+    struct iovec     headers[NGX_IOVS_PREALLOCATE];
+    struct iovec     trailers[NGX_IOVS_PREALLOCATE];
 
     wev = c->write;
 
@@ -83,12 +76,12 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 
     header.elts = headers;
     header.size = sizeof(struct iovec);
-    header.nalloc = NGX_HEADERS;
+    header.nalloc = NGX_IOVS_PREALLOCATE;
     header.pool = c->pool;
 
     trailer.elts = trailers;
     trailer.size = sizeof(struct iovec);
-    trailer.nalloc = NGX_TRAILERS;
+    trailer.nalloc = NGX_IOVS_PREALLOCATE;
     trailer.pool = c->pool;
 
     for ( ;; ) {
@@ -96,7 +89,6 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
         file_size = 0;
         header_size = 0;
         eintr = 0;
-        complete = 0;
         prev_send = send;
 
         header.nelts = 0;
@@ -362,48 +354,9 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
             sent = rc > 0 ? rc : 0;
         }
 
-        if (send - prev_send == sent) {
-            complete = 1;
-        }
-
         c->sent += sent;
 
-        for ( /* void */ ; in; in = in->next) {
-
-            if (ngx_buf_special(in->buf)) {
-                continue;
-            }
-
-            if (sent == 0) {
-                break;
-            }
-
-            size = ngx_buf_size(in->buf);
-
-            if (sent >= size) {
-                sent -= size;
-
-                if (ngx_buf_in_memory(in->buf)) {
-                    in->buf->pos = in->buf->last;
-                }
-
-                if (in->buf->in_file) {
-                    in->buf->file_pos = in->buf->file_last;
-                }
-
-                continue;
-            }
-
-            if (ngx_buf_in_memory(in->buf)) {
-                in->buf->pos += (size_t) sent;
-            }
-
-            if (in->buf->in_file) {
-                in->buf->file_pos += sent;
-            }
-
-            break;
-        }
+        in = ngx_handle_sent_chain(in, sent);
 
 #if (NGX_HAVE_AIO_SENDFILE)
         if (c->busy_sendfile) {
@@ -428,7 +381,7 @@ ngx_freebsd_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
             continue;
         }
 
-        if (!complete) {
+        if (send - prev_send != sent) {
             wev->ready = 0;
             return in;
         }
diff --git a/src/os/unix/ngx_linux_sendfile_chain.c b/src/os/unix/ngx_linux_sendfile_chain.c
index 16395f943..1060852a0 100644
--- a/src/os/unix/ngx_linux_sendfile_chain.c
+++ b/src/os/unix/ngx_linux_sendfile_chain.c
@@ -27,13 +27,6 @@
 #define NGX_SENDFILE_MAXSIZE  2147483647L
 
 
-#if (IOV_MAX > 64)
-#define NGX_HEADERS  64
-#else
-#define NGX_HEADERS  IOV_MAX
-#endif
-
-
 ngx_chain_t *
 ngx_linux_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 {
@@ -43,11 +36,11 @@ ngx_linux_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
     size_t         file_size;
     ngx_err_t      err;
     ngx_buf_t     *file;
-    ngx_uint_t     eintr, complete;
+    ngx_uint_t     eintr;
     ngx_array_t    header;
     ngx_event_t   *wev;
     ngx_chain_t   *cl;
-    struct iovec  *iov, headers[NGX_HEADERS];
+    struct iovec  *iov, headers[NGX_IOVS_PREALLOCATE];
 #if (NGX_HAVE_SENDFILE64)
     off_t          offset;
 #else
@@ -72,14 +65,13 @@ ngx_linux_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 
     header.elts = headers;
     header.size = sizeof(struct iovec);
-    header.nalloc = NGX_HEADERS;
+    header.nalloc = NGX_IOVS_PREALLOCATE;
     header.pool = c->pool;
 
     for ( ;; ) {
         file = NULL;
         file_size = 0;
         eintr = 0;
-        complete = 0;
         prev_send = send;
 
         header.nelts = 0;
@@ -319,54 +311,15 @@ ngx_linux_sendfile_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
             ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "writev: %O", sent);
         }
 
-        if (send - prev_send == sent) {
-            complete = 1;
-        }
-
         c->sent += sent;
 
-        for ( /* void */ ; in; in = in->next) {
-
-            if (ngx_buf_special(in->buf)) {
-                continue;
-            }
-
-            if (sent == 0) {
-                break;
-            }
-
-            size = ngx_buf_size(in->buf);
-
-            if (sent >= size) {
-                sent -= size;
-
-                if (ngx_buf_in_memory(in->buf)) {
-                    in->buf->pos = in->buf->last;
-                }
-
-                if (in->buf->in_file) {
-                    in->buf->file_pos = in->buf->file_last;
-                }
-
-                continue;
-            }
-
-            if (ngx_buf_in_memory(in->buf)) {
-                in->buf->pos += (size_t) sent;
-            }
-
-            if (in->buf->in_file) {
-                in->buf->file_pos += sent;
-            }
-
-            break;
-        }
+        in = ngx_handle_sent_chain(in, sent);
 
         if (eintr) {
             continue;
         }
 
-        if (!complete) {
+        if (send - prev_send != sent) {
             wev->ready = 0;
             return in;
         }
diff --git a/src/os/unix/ngx_os.h b/src/os/unix/ngx_os.h
index c646e2aa5..1033d8825 100644
--- a/src/os/unix/ngx_os.h
+++ b/src/os/unix/ngx_os.h
@@ -56,6 +56,13 @@ ngx_chain_t *ngx_aio_write_chain(ngx_connection_t *c, ngx_chain_t *in,
 #endif
 
 
+#if (IOV_MAX > 64)
+#define NGX_IOVS_PREALLOCATE  64
+#else
+#define NGX_IOVS_PREALLOCATE  IOV_MAX
+#endif
+
+
 extern ngx_os_io_t  ngx_os_io;
 extern ngx_int_t    ngx_ncpu;
 extern ngx_int_t    ngx_max_sockets;
diff --git a/src/os/unix/ngx_readv_chain.c b/src/os/unix/ngx_readv_chain.c
index e4eb5ff32..3cba80ccc 100644
--- a/src/os/unix/ngx_readv_chain.c
+++ b/src/os/unix/ngx_readv_chain.c
@@ -10,15 +10,6 @@
 #include <ngx_event.h>
 
 
-#if (IOV_MAX > 64)
-#define NGX_IOVS  64
-#else
-#define NGX_IOVS  IOV_MAX
-#endif
-
-
-#if (NGX_HAVE_KQUEUE)
-
 ssize_t
 ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
 {
@@ -27,10 +18,12 @@ ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
     ngx_err_t      err;
     ngx_array_t    vec;
     ngx_event_t   *rev;
-    struct iovec  *iov, iovs[NGX_IOVS];
+    struct iovec  *iov, iovs[NGX_IOVS_PREALLOCATE];
 
     rev = c->read;
 
+#if (NGX_HAVE_KQUEUE)
+
     if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
         ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
                        "readv: eof:%d, avail:%d, err:%d",
@@ -58,6 +51,8 @@ ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
         }
     }
 
+#endif
+
     prev = NULL;
     iov = NULL;
     size = 0;
@@ -65,7 +60,7 @@ ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
     vec.elts = iovs;
     vec.nelts = 0;
     vec.size = sizeof(struct iovec);
-    vec.nalloc = NGX_IOVS;
+    vec.nalloc = NGX_IOVS_PREALLOCATE;
     vec.pool = c->pool;
 
     /* coalesce the neighbouring bufs */
@@ -96,12 +91,13 @@ ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
     ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                    "readv: %d, last:%d", vec.nelts, iov->iov_len);
 
-    rev = c->read;
-
     do {
         n = readv(c->fd, (struct iovec *) vec.elts, vec.nelts);
 
         if (n >= 0) {
+
+#if (NGX_HAVE_KQUEUE)
+
             if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
                 rev->available -= n;
 
@@ -141,6 +137,8 @@ ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
                 return n;
             }
 
+#endif /* NGX_HAVE_KQUEUE */
+
             if (n < size && !(ngx_event_flags & NGX_USE_GREEDY_EVENT)) {
                 rev->ready = 0;
             }
@@ -174,98 +172,3 @@ ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
 
     return n;
 }
-
-#else /* ! NGX_HAVE_KQUEUE */
-
-ssize_t
-ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
-{
-    u_char        *prev;
-    ssize_t        n, size;
-    ngx_err_t      err;
-    ngx_array_t    vec;
-    ngx_event_t   *rev;
-    struct iovec  *iov, iovs[NGX_IOVS];
-
-    prev = NULL;
-    iov = NULL;
-    size = 0;
-
-    vec.elts = iovs;
-    vec.nelts = 0;
-    vec.size = sizeof(struct iovec);
-    vec.nalloc = NGX_IOVS;
-    vec.pool = c->pool;
-
-    /* coalesce the neighbouring bufs */
-
-    while (chain) {
-        if (prev == chain->buf->last) {
-            iov->iov_len += chain->buf->end - chain->buf->last;
-
-        } else {
-            if (vec.nelts >= IOV_MAX) {
-                break;
-            }
-
-            iov = ngx_array_push(&vec);
-            if (iov == NULL) {
-                return NGX_ERROR;
-            }
-
-            iov->iov_base = (void *) chain->buf->last;
-            iov->iov_len = chain->buf->end - chain->buf->last;
-        }
-
-        size += chain->buf->end - chain->buf->last;
-        prev = chain->buf->end;
-        chain = chain->next;
-    }
-
-    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                   "readv: %d:%d", vec.nelts, iov->iov_len);
-
-    rev = c->read;
-
-    do {
-        n = readv(c->fd, (struct iovec *) vec.elts, vec.nelts);
-
-        if (n == 0) {
-            rev->ready = 0;
-            rev->eof = 1;
-
-            return n;
-
-        } else if (n > 0) {
-
-            if (n < size && !(ngx_event_flags & NGX_USE_GREEDY_EVENT)) {
-                rev->ready = 0;
-            }
-
-            return n;
-        }
-
-        err = ngx_socket_errno;
-
-        if (err == NGX_EAGAIN || err == NGX_EINTR) {
-            ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
-                           "readv() not ready");
-            n = NGX_AGAIN;
-
-        } else {
-            n = ngx_connection_error(c, err, "readv() failed");
-            break;
-        }
-
-    } while (err == NGX_EINTR);
-
-    rev->ready = 0;
-
-    if (n == NGX_ERROR) {
-        c->read->error = 1;
-    }
-
-    return n;
-}
-
-#endif /* NGX_HAVE_KQUEUE */
diff --git a/src/os/unix/ngx_solaris_sendfilev_chain.c b/src/os/unix/ngx_solaris_sendfilev_chain.c
index 37bb09d96..ba328c810 100644
--- a/src/os/unix/ngx_solaris_sendfilev_chain.c
+++ b/src/os/unix/ngx_solaris_sendfilev_chain.c
@@ -35,12 +35,7 @@ ngx_chain_t *ngx_solaris_sendfilev_chain(ngx_connection_t *c, ngx_chain_t *in,
 #endif
 
 
-#if (IOV_MAX > 64)
-#define NGX_SENDFILEVECS  64
-#else
-#define NGX_SENDFILEVECS  IOV_MAX
-#endif
-
+#define NGX_SENDFILEVECS  NGX_IOVS_PREALLOCATE
 
 
 ngx_chain_t *
@@ -51,7 +46,7 @@ ngx_solaris_sendfilev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
     off_t           size, send, prev_send, aligned, fprev;
     size_t          sent;
     ssize_t         n;
-    ngx_int_t       eintr, complete;
+    ngx_int_t       eintr;
     ngx_err_t       err;
     sendfilevec_t  *sfv, sfvs[NGX_SENDFILEVECS];
     ngx_array_t     vec;
@@ -89,7 +84,6 @@ ngx_solaris_sendfilev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
         fprev = 0;
         sfv = NULL;
         eintr = 0;
-        complete = 0;
         sent = 0;
         prev_send = send;
 
@@ -201,54 +195,15 @@ ngx_solaris_sendfilev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
         ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
                        "sendfilev: %z %z", n, sent);
 
-        if (send - prev_send == (off_t) sent) {
-            complete = 1;
-        }
-
         c->sent += sent;
 
-        for ( /* void */ ; in; in = in->next) {
-
-            if (ngx_buf_special(in->buf)) {
-                continue;
-            }
-
-            if (sent == 0) {
-                break;
-            }
-
-            size = ngx_buf_size(in->buf);
-
-            if ((off_t) sent >= size) {
-                sent = (size_t) ((off_t) sent - size);
-
-                if (ngx_buf_in_memory(in->buf)) {
-                    in->buf->pos = in->buf->last;
-                }
-
-                if (in->buf->in_file) {
-                    in->buf->file_pos = in->buf->file_last;
-                }
-
-                continue;
-            }
-
-            if (ngx_buf_in_memory(in->buf)) {
-                in->buf->pos += sent;
-            }
-
-            if (in->buf->in_file) {
-                in->buf->file_pos += sent;
-            }
-
-            break;
-        }
+        in = ngx_handle_sent_chain(in, sent);
 
         if (eintr) {
             continue;
         }
 
-        if (!complete) {
+        if (send - prev_send != (off_t) sent) {
             wev->ready = 0;
             return in;
         }
diff --git a/src/os/unix/ngx_writev_chain.c b/src/os/unix/ngx_writev_chain.c
index 805982d65..95af2da7a 100644
--- a/src/os/unix/ngx_writev_chain.c
+++ b/src/os/unix/ngx_writev_chain.c
@@ -10,25 +10,18 @@
 #include <ngx_event.h>
 
 
-#if (IOV_MAX > 64)
-#define NGX_IOVS  64
-#else
-#define NGX_IOVS  IOV_MAX
-#endif
-
-
 ngx_chain_t *
 ngx_writev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 {
     u_char        *prev;
     ssize_t        n, size, sent;
     off_t          send, prev_send;
-    ngx_uint_t     eintr, complete;
+    ngx_uint_t     eintr;
     ngx_err_t      err;
     ngx_array_t    vec;
     ngx_chain_t   *cl;
     ngx_event_t   *wev;
-    struct iovec  *iov, iovs[NGX_IOVS];
+    struct iovec  *iov, iovs[NGX_IOVS_PREALLOCATE];
 
     wev = c->write;
 
@@ -57,14 +50,13 @@ ngx_writev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 
     vec.elts = iovs;
     vec.size = sizeof(struct iovec);
-    vec.nalloc = NGX_IOVS;
+    vec.nalloc = NGX_IOVS_PREALLOCATE;
     vec.pool = c->pool;
 
     for ( ;; ) {
         prev = NULL;
         iov = NULL;
         eintr = 0;
-        complete = 0;
         prev_send = send;
 
         vec.nelts = 0;
@@ -137,49 +129,21 @@ ngx_writev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 
         ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "writev: %z", sent);
 
-        if (send - prev_send == sent) {
-            complete = 1;
-        }
-
         c->sent += sent;
 
-        for (cl = in; cl; cl = cl->next) {
-
-            if (ngx_buf_special(cl->buf)) {
-                continue;
-            }
-
-            if (sent == 0) {
-                break;
-            }
-
-            size = cl->buf->last - cl->buf->pos;
-
-            if (sent >= size) {
-                sent -= size;
-                cl->buf->pos = cl->buf->last;
-
-                continue;
-            }
-
-            cl->buf->pos += sent;
-
-            break;
-        }
+        in = ngx_handle_sent_chain(in, sent);
 
         if (eintr) {
             continue;
         }
 
-        if (!complete) {
+        if (send - prev_send != sent) {
             wev->ready = 0;
-            return cl;
+            return in;
         }
 
-        if (send >= limit || cl == NULL) {
-            return cl;
+        if (send >= limit || in == NULL) {
+            return in;
         }
-
-        in = cl;
     }
 }