From 6c56b53850c54417a9facd354100c34eed3e8e4e Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <mars@box>
Date: Fri, 1 Sep 2017 14:46:54 +0200
Subject: [PATCH] infra: fix deadlock on leave-cluster & friends

root@m1:~# cat /proc/2661/stack
[<ffffffff810591cc>] kthread_stop+0x7f/0x10d
[<ffffffffa01660a5>] _kill_peer.isra.7+0xf9/0x1ea [mars]
[<ffffffffa01661f2>] peer_destruct+0xe/0x10 [mars]
[<ffffffffa015c66a>] mars_free_dent+0x188/0x1b4 [mars]
[<ffffffffa015ca5a>] mars_dent_work+0x3c4/0x563 [mars]
[<ffffffffa01652d7>] _main_thread+0x2b2/0x88d [mars]
[<ffffffff81059145>] kthread+0xb5/0xbd
[<ffffffff81660a19>] ret_from_fork+0x49/0x80
[<ffffffffffffffff>] 0xffffffffffffffff

root@m1:~# cat /proc/4473/stack
[<ffffffff81342154>] call_rwsem_down_read_failed+0x14/0x30
[<ffffffffa015a554>] mars_find_dent+0x19/0x3d [mars]
[<ffffffffa015dadc>] _mars_translate_hostname+0x86/0x126 [mars]
[<ffffffffa0166663>] peer_thread+0x46f/0xdc0 [mars]
[<ffffffff81059145>] kthread+0xb5/0xbd
[<ffffffff81660a19>] ret_from_fork+0x49/0x80
[<ffffffffffffffff>] 0xffffffffffffffff
---
 kernel/sy_old/sy_net.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/kernel/sy_old/sy_net.c b/kernel/sy_old/sy_net.c
index ea8736a2..301dbb5d 100644
--- a/kernel/sy_old/sy_net.c
+++ b/kernel/sy_old/sy_net.c
@@ -36,14 +36,9 @@
 static
 char *_mars_translate_hostname(const char *name)
 {
-	struct mars_global *global = mars_global;
 	char *res = brick_strdup(name);
-	struct mars_dent *test;
 	char *tmp;
-
-	if (unlikely(!global)) {
-		goto done;
-	}
+	char *trans;
 
 	for (tmp = res; *tmp; tmp++) {
 		if (*tmp == ':') {
@@ -57,16 +52,15 @@ char *_mars_translate_hostname(const char *name)
 		goto done;
 	}
 
-	test = mars_find_dent(global, tmp);
-	if (test && test->new_link) {
-		MARS_DBG("'%s' => '%s'\n", tmp, test->new_link);
+	trans = mars_readlink(tmp);
+	if (trans && trans[0]) {
+		MARS_DBG("'%s' => '%s'\n", tmp, trans);
 		brick_string_free(res);
-		res = brick_strdup(test->new_link);
+		res = trans;
 	} else {
 		MARS_DBG("no translation for '%s'\n", tmp);
 	}
 	brick_string_free(tmp);
-
 done:
 	return res;
 }