From 7b3f4110631edb5fb33c73082210949ec29d3faf Mon Sep 17 00:00:00 2001
From: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Date: Thu, 25 Apr 2019 14:59:03 +0200
Subject: [PATCH] thread: fix deadlock in spdk_for_each_thread error handling

We could return from spdk_for_each_thread() without
unlocking the global threading mutex, rendering the
entire SPDK application useless.

Change-Id: I641c7b36db996f9a36310332279648014579de83
Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/452087
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
---
 lib/thread/thread.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/thread/thread.c b/lib/thread/thread.c
index c66281bd0..ba367cd65 100644
--- a/lib/thread/thread.c
+++ b/lib/thread/thread.c
@@ -786,7 +786,6 @@ spdk_for_each_thread(spdk_msg_fn fn, void *ctx, spdk_msg_fn cpl)
 	ct->ctx = ctx;
 	ct->cpl = cpl;
 
-	pthread_mutex_lock(&g_devlist_mutex);
 	thread = _get_thread();
 	if (!thread) {
 		SPDK_ERRLOG("No thread allocated\n");
@@ -795,6 +794,8 @@ spdk_for_each_thread(spdk_msg_fn fn, void *ctx, spdk_msg_fn cpl)
 		return;
 	}
 	ct->orig_thread = thread;
+
+	pthread_mutex_lock(&g_devlist_mutex);
 	ct->cur_thread = TAILQ_FIRST(&g_threads);
 	pthread_mutex_unlock(&g_devlist_mutex);