BUG/MINOR: stats: decrement srv refcount on stats-file release

Servers instance may be removed at runtime. This can occurs during a
stat dump which currently references this server instance. This case is
protected by server refcount to prevent the server immediate release.

CLI output may be interrupted prior to stats dump completion, for
example if client CLI has been disconnected before the full response
transfer. As such, srv_drop() must be called in every stats dump release
callback.

srv_drop() was missing for stats-file dump release callback. This could
cause a race condition which would prevent a server instance to be fully
removed. Fix this by adding srv_drop() invokation into
cli_io_handler_release_dump_stat_file().

This should be backported up to 3.0.

diff --git a/src/stats.c b/src/stats.c
index c3f26b085dd9aca0f984b2f0ff9634a2528a2d1c..868b92555b40b1de02ab41a1eec890c19a3cd463 100644 (file)
--- a/src/stats.c
+++ b/src/stats.c
@@ -1064,6 +1064,10 @@ static int cli_io_handler_dump_stat_file(struct appctx *appctx)
 
 static void cli_io_handler_release_dump_stat_file(struct appctx *appctx)
 {
+       struct show_stat_ctx *ctx = appctx->svcctx;
+
+       if (ctx->px_st == STAT_PX_ST_SV)
+               srv_drop(ctx->obj2);
 }
 
 int stats_allocate_proxy_counters_internal(struct extra_counters **counters,