f2fs: clear discard_wake earlier

If SBI_NEED_FSCK is set, discard_wake will never be cleared. As a
result, the condition of wait_event_interruptible_timeout() is always
true, which gets discard thread run too frequently.
Signed-off-by: NSheng Yong <shengyong1@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/segment.c

@@ -1402,6 +1402,10 @@ static int issue_discard_thread(void *data)
 				kthread_should_stop() || freezing(current) ||
 				dcc->discard_wake,
 				msecs_to_jiffies(wait_ms));
+
+		if (dcc->discard_wake)
+			dcc->discard_wake = 0;
+
 		if (try_to_freeze())
 			continue;
 		if (f2fs_readonly(sbi->sb))
@@ -1413,9 +1417,6 @@ static int issue_discard_thread(void *data)
 			continue;
 		}
 
-		if (dcc->discard_wake)
-			dcc->discard_wake = 0;
-
 		if (sbi->gc_mode == GC_URGENT)
 			__init_discard_policy(sbi, &dpolicy, DPOLICY_FORCE, 1);