dm writecache: skip writecache_wait for pmem mode

The array bio_in_progress[2] only have chance to be increased and
decreased with ssd mode. For pmem mode, they are not involved at all.
So skip writecache_wait_for_ios in writecache_flush for pmem.

Suggested-by: Doris Yu <tyu1@lenovo.com>
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index c481947..d06b8aa 100644 (file)
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -726,7 +726,8 @@ static void writecache_flush(struct dm_writecache *wc)
        }
        writecache_commit_flushed(wc);
 
-       writecache_wait_for_ios(wc, WRITE);
+       if (!WC_MODE_PMEM(wc))
+               writecache_wait_for_ios(wc, WRITE);
 
        wc->seq_count++;
        pmem_assign(sb(wc)->seq_count, cpu_to_le64(wc->seq_count));