signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread()

jffs2_garbage_collect_thread() can race with SIGCONT and sleep in
TASK_STOPPED state after it was already sent. Add the new helper,
kernel_signal_stop(), which does this correctly.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c
index f3145fd86d86..53cc7350af33 100644
--- a/fs/jffs2/background.c
+++ b/fs/jffs2/background.c
@@ -132,8 +132,7 @@ static int jffs2_garbage_collect_thread(void *_c)
                         case SIGSTOP:
                                 jffs2_dbg(1, "%s(): SIGSTOP received\n",
                                           __func__);
-                                set_current_state(TASK_STOPPED);
-                                schedule();
+                                kernel_signal_stop();
                                 break;
 
                         case SIGKILL: