From 00fcc6a987f1d45a9eac91242de7e3527451242e Mon Sep 17 00:00:00 2001 From: Maxim Dounin Date: Thu, 3 Mar 2016 21:14:19 +0300 Subject: [PATCH] Copy filter: fixed sendfile aio handlers to set ctx->aio. Sendfile handlers (aio preload and thread handler) are called within ctx->output_filter() in ngx_output_chain(), and hence ctx->aio cannot be set directly in ngx_output_chain(). Meanwhile, it must be set to make sure loop within ngx_output_chain() will be properly terminated. There are no known cases that trigger the problem, though in theory something like aio + sub filter (something that needs body in memory, and can also free some memory buffers) + sendfile can result in "task already active" and "second aio post" alerts. The fix is to set ctx->aio in ngx_http_copy_aio_sendfile_preload() and ngx_http_copy_thread_handler(). For consistency, ctx->aio is no longer set explicitly in ngx_output_chain_copy_buf(), as it's now done in ngx_http_copy_thread_handler(). --- src/core/ngx_output_chain.c | 1 - src/http/ngx_http_copy_filter_module.c | 16 ++++++++++++---- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/src/core/ngx_output_chain.c b/src/core/ngx_output_chain.c index 252359af6..b8361dcd6 100644 --- a/src/core/ngx_output_chain.c +++ b/src/core/ngx_output_chain.c @@ -581,7 +581,6 @@ ngx_output_chain_copy_buf(ngx_output_chain_ctx_t *ctx) n = ngx_thread_read(&ctx->thread_task, src->file, dst->pos, (size_t) size, src->file_pos, ctx->pool); if (n == NGX_AGAIN) { - ctx->aio = 1; return NGX_AGAIN; } diff --git a/src/http/ngx_http_copy_filter_module.c b/src/http/ngx_http_copy_filter_module.c index c6d03eec0..c696fb6f9 100644 --- a/src/http/ngx_http_copy_filter_module.c +++ b/src/http/ngx_http_copy_filter_module.c @@ -204,10 +204,11 @@ ngx_http_copy_aio_event_handler(ngx_event_t *ev) static ssize_t ngx_http_copy_aio_sendfile_preload(ngx_buf_t *file) { - ssize_t n; - static u_char buf[1]; - ngx_event_aio_t *aio; - ngx_http_request_t *r; + ssize_t n; + static u_char buf[1]; + ngx_event_aio_t *aio; + ngx_http_request_t *r; + ngx_output_chain_ctx_t *ctx; n = ngx_file_aio_read(file->file, buf, 1, file->file_pos, NULL); @@ -218,6 +219,9 @@ ngx_http_copy_aio_sendfile_preload(ngx_buf_t *file) r = aio->data; r->main->blocked++; r->aio = 1; + + ctx = ngx_http_get_module_ctx(r, ngx_http_copy_filter_module); + ctx->aio = 1; } return n; @@ -252,6 +256,7 @@ ngx_http_copy_thread_handler(ngx_thread_task_t *task, ngx_file_t *file) ngx_str_t name; ngx_thread_pool_t *tp; ngx_http_request_t *r; + ngx_output_chain_ctx_t *ctx; ngx_http_core_loc_conf_t *clcf; r = file->thread_ctx; @@ -285,6 +290,9 @@ ngx_http_copy_thread_handler(ngx_thread_task_t *task, ngx_file_t *file) r->main->blocked++; r->aio = 1; + ctx = ngx_http_get_module_ctx(r, ngx_http_copy_filter_module); + ctx->aio = 1; + return NGX_OK; }