f2fs: check discard command number before traversing discard pending list

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@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 29403540ff6ed00d8797504388557ded2ce1e631..b5a40a39a03fb448bf739e6b74c9a3f1c11fe3b3 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1759,6 +1759,8 @@ 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);