[PATCH v4 06/10] Add the function of colo_compare_cleanup

[leirao <lei.rao@intel.com>]

From: "Rao, Lei" <lei.rao@intel.com>

This patch fixes the following:
    #0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
    #1  0x00007f6ae4559859 in __GI_abort () at abort.c:79
    #2  0x0000559aaa386720 in error_exit (err=16, msg=0x559aaa5973d0 <__func__.16227> "qemu_mutex_destroy") at util/qemu-thread-posix.c:36
    #3  0x0000559aaa3868c5 in qemu_mutex_destroy (mutex=0x559aabffe828) at util/qemu-thread-posix.c:69
    #4  0x0000559aaa2f93a8 in char_finalize (obj=0x559aabffe800) at chardev/char.c:285
    #5  0x0000559aaa23318a in object_deinit (obj=0x559aabffe800, type=0x559aabfd7d20) at qom/object.c:606
    #6  0x0000559aaa2331b8 in object_deinit (obj=0x559aabffe800, type=0x559aabfd9060) at qom/object.c:610
    #7  0x0000559aaa233200 in object_finalize (data=0x559aabffe800) at qom/object.c:620
    #8  0x0000559aaa234202 in object_unref (obj=0x559aabffe800) at qom/object.c:1074
    #9  0x0000559aaa2356b6 in object_finalize_child_property (obj=0x559aac0dac10, name=0x559aac778760 "compare0-0", opaque=0x559aabffe800) at qom/object.c:1584
    #10 0x0000559aaa232f70 in object_property_del_all (obj=0x559aac0dac10) at qom/object.c:557
    #11 0x0000559aaa2331ed in object_finalize (data=0x559aac0dac10) at qom/object.c:619
    #12 0x0000559aaa234202 in object_unref (obj=0x559aac0dac10) at qom/object.c:1074
    #13 0x0000559aaa2356b6 in object_finalize_child_property (obj=0x559aac0c75c0, name=0x559aac0dadc0 "chardevs", opaque=0x559aac0dac10) at qom/object.c:1584
    #14 0x0000559aaa233071 in object_property_del_child (obj=0x559aac0c75c0, child=0x559aac0dac10, errp=0x0) at qom/object.c:580
    #15 0x0000559aaa233155 in object_unparent (obj=0x559aac0dac10) at qom/object.c:599
    #16 0x0000559aaa2fb721 in qemu_chr_cleanup () at chardev/char.c:1159
    #17 0x0000559aa9f9b110 in main (argc=54, argv=0x7ffeb62fa998, envp=0x7ffeb62fab50) at vl.c:4539

When chardev is cleaned up, chr_write_lock needs to be destroyed. But
the colo-compare module is not cleaned up normally before it when the
guest poweroff. It is holding chr_write_lock at this time. This will
cause qemu crash.So we add the function of colo_compare_cleanup() before
qemu_chr_cleanup() to fix the bug.

Signed-off-by: Lei Rao <lei.rao@intel.com>
---
 net/colo-compare.c | 10 ++++++++++
 net/colo-compare.h |  1 +
 net/net.c          |  4 ++++
 3 files changed, 15 insertions(+)

diff --git a/net/colo-compare.c b/net/colo-compare.c
index c142c08..5b538f4 100644
--- a/net/colo-compare.c
+++ b/net/colo-compare.c
@@ -1402,6 +1402,16 @@ static void colo_compare_init(Object *obj)
                              compare_set_vnet_hdr);
 }
 
+void colo_compare_cleanup(void)
+{
+    CompareState *tmp = NULL;
+    CompareState *n = NULL;
+
+    QTAILQ_FOREACH_SAFE(tmp, &net_compares, next, n) {
+        object_unparent(OBJECT(tmp));
+    }
+}
+
 static void colo_compare_finalize(Object *obj)
 {
     CompareState *s = COLO_COMPARE(obj);
diff --git a/net/colo-compare.h b/net/colo-compare.h
index 22ddd51..b055270 100644
--- a/net/colo-compare.h
+++ b/net/colo-compare.h
@@ -20,5 +20,6 @@
 void colo_notify_compares_event(void *opaque, int event, Error **errp);
 void colo_compare_register_notifier(Notifier *notify);
 void colo_compare_unregister_notifier(Notifier *notify);
+void colo_compare_cleanup(void);
 
 #endif /* QEMU_COLO_COMPARE_H */
diff --git a/net/net.c b/net/net.c
index 725a4e1..8fcb2e7 100644
--- a/net/net.c
+++ b/net/net.c
@@ -53,6 +53,7 @@
 #include "sysemu/sysemu.h"
 #include "sysemu/runstate.h"
 #include "sysemu/sysemu.h"
+#include "net/colo-compare.h"
 #include "net/filter.h"
 #include "qapi/string-output-visitor.h"
 #include "qapi/hmp-output-visitor.h"
@@ -1463,6 +1464,9 @@ void net_cleanup(void)
 {
     NetClientState *nc;
 
+    /*cleanup colo compare module for COLO*/
+    colo_compare_cleanup();
+
     /* We may del multiple entries during qemu_del_net_client(),
      * so QTAILQ_FOREACH_SAFE() is also not safe here.
      */
-- 
1.8.3.1