From: "tang.junhui" <tang.junhui@xxxxxxxxxx>
SIGUSR2 is not blocked by default, it would cause bellow conflict
in removing of the last path:
-------------------------------------------------------------
uevent processing thread | waiter thread
-----------------------------------------|-------------------
uev_remove_path() | waiteventloop()
lock(&vecs->lock) |
ev_remove_path() |
dm_queue_if_no_path()----------------|----> dm_task_run()
flush_map() | |
remove_map_and_stop_waiter() | -> pthread_cleanup_push(cleanup_lock, &waiter->vecs->lock);
_remove_map() | lock(&waiter->vecs->lock)//wait for the locker
stop_waiter_thread() |
pthread_cancel(thread) |
pthread_kill(thread,SIGUSR2)-|------> sigusr2 (int sig)
| condlog()
| fprintf() //it has test cancel point
| cleanup_lock() //thread cancel, and pop, which unlock the
| locker of uevent processing thread
--------------------------------------------------------------
Since SIGUSR2 is only needed when waiter thread running in dm_task_run(),
and it has already been unblocked before dm_task_run(), so this patch block
SIGUSR2 for other times.
Change-Id: I8c46292dc954415764ebbe054498b4f7ea53c1c6
Signed-off-by: tang.junhui <tang.junhui@xxxxxxxxxx>
---
multipathd/main.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/multipathd/main.c b/multipathd/main.c
index adc3258..fe69abd 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -2181,6 +2181,12 @@ sigusr2 (int sig)
static void
signal_init(void)
{
+ sigset_t set;
+
+ sigemptyset(&set);
+ sigaddset(&set, SIGUSR2);
+ pthread_sigmask(SIG_SETMASK, &set, NULL);
+
signal_set(SIGHUP, sighup);
signal_set(SIGUSR1, sigusr1);
signal_set(SIGUSR2, sigusr2);
--
2.8.1.windows.1
--
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