From: Xiubo Li <lixiubo@cmss.chinamobile.com>
Date: Thu, 15 Jun 2017 15:05:31 +0800
Subject: tcmu: Fix module removal due to stuck unmap_thread thread again
Git-commit: 07932a023af3cd728390ffdaeffb78e357123181
Patch-mainline: v4.13-rc1
References: fate#323946

Because the unmap code just after the schdule() returned may take
a long time and if the kthread_stop() is fired just when in this
routine, the module removal maybe stuck too.

Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Acked-by: Lee Duncan <lduncan@suse.com>
---
 drivers/target/target_core_user.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index afc1fd6bacaf..a60a66d61146 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -1707,7 +1707,7 @@ static int unmap_thread_fn(void *data)
 	struct page *page;
 	int i;
 
-	while (1) {
+	while (!kthread_should_stop()) {
 		DEFINE_WAIT(__wait);
 
 		prepare_to_wait(&unmap_wait, &__wait, TASK_INTERRUPTIBLE);