pyrox.dev
1Fix for a deadlock:
2https://bugzilla.gnome.org/show_bug.cgi?id=667230
3
4From cc14440eface093548cb3bc7814da11d9a99d283 Mon Sep 17 00:00:00 2001
5From: Anssi Hannula <anssi@mageia.org>
6Date: Wed, 4 Jan 2012 00:23:55 +0200
7Subject: [PATCH] fix possible server deadlock in ih_sub_cancel
8
9ih_sub_foreach() calls ih_sub_cancel() while inotify_lock is locked.
10However, ih_sub_cancel() locks it again, and locking GMutex recursively
11causes undefined behaviour.
12
13Fix that by removing locking from ih_sub_cancel() as ih_sub_foreach()
14is its only user. Also make the function static so that it won't
15accidentally get used by other files without locking (inotify-helper.h
16is an internal server header).
17
18This should fix the intermittent deadlocks I've been experiencing
19causing KDE applications to no longer start, and probably also
20http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=542361
21---
22 server/inotify-helper.c | 7 ++-----
23 server/inotify-helper.h | 1 -
24 2 files changed, 2 insertions(+), 6 deletions(-)
25
26diff --git a/server/inotify-helper.c b/server/inotify-helper.c
27index d77203e..0789fa4 100644
28--- a/server/inotify-helper.c
29+++ b/server/inotify-helper.c
30@@ -123,13 +123,11 @@ ih_sub_add (ih_sub_t * sub)
31
32 /**
33 * Cancels a subscription which was being monitored.
34+ * inotify_lock must be held when calling.
35 */
36-gboolean
37+static gboolean
38 ih_sub_cancel (ih_sub_t * sub)
39 {
40- G_LOCK(inotify_lock);
41-
42-
43 if (!sub->cancelled)
44 {
45 IH_W("cancelling %s\n", sub->pathname);
46@@ -140,7 +138,6 @@ ih_sub_cancel (ih_sub_t * sub)
47 sub_list = g_list_remove (sub_list, sub);
48 }
49
50- G_UNLOCK(inotify_lock);
51 return TRUE;
52 }
53
54diff --git a/server/inotify-helper.h b/server/inotify-helper.h
55index 5d3b6d0..d36b5fd 100644
56--- a/server/inotify-helper.h
57+++ b/server/inotify-helper.h
58@@ -34,7 +34,6 @@ gboolean ih_startup (event_callback_t ecb,
59 found_callback_t fcb);
60 gboolean ih_running (void);
61 gboolean ih_sub_add (ih_sub_t *sub);
62-gboolean ih_sub_cancel (ih_sub_t *sub);
63
64 /* Return FALSE from 'f' if the subscription should be cancelled */
65 void ih_sub_foreach (void *callerdata, gboolean (*f)(ih_sub_t *sub, void *callerdata));
66--
671.7.7.2
68