[PATCH] f2fs: check discard command number before traversing discard pending list

[Chao Yu]

In trim thread, let's add a condition to check discard command number
before traversing discard pending list, it can avoid unneeded traversing
if there is no discard command.

Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
 fs/f2fs/segment.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index deaf57e13125..1e674c117ce3 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1769,6 +1769,8 @@ static int issue_discard_thread(void *data)
 			wait_ms = dpolicy.max_interval;
 			continue;
 		}
+		if (!atomic_read(&dcc->discard_cmd_cnt))
+			continue;
 
 		if (sbi->gc_mode == GC_URGENT_HIGH)
 			__init_discard_policy(sbi, &dpolicy, DPOLICY_FORCE, 1);
-- 
2.29.2