bcache: correct dirty data statistics

commit 2e17a26 upstream.

When bcache device is clean, dirty keys may still exist after
journal replay, so we need to count these dirty keys even
device in clean status, otherwise after writeback, the amount
of dirty data would be incorrect.

Signed-off-by: Tang Junhui <[email protected]>
Cc: [email protected]
Signed-off-by: Coly Li <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Tang Junhui

drivers/md/bcache/super.c

@@ -1148,11 +1148,12 @@ int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
 	}
 
 	if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
-		bch_sectors_dirty_init(&dc->disk);
 		atomic_set(&dc->has_dirty, 1);
 		bch_writeback_queue(dc);
 	}
 
+	bch_sectors_dirty_init(&dc->disk);
+
 	bch_cached_dev_run(dc);
 	bcache_device_link(&dc->disk, c, "bdev");
 	atomic_inc(&c->attached_dev_nr);