[PATCH 4.19 014/361] bcache: correct dirty data statistics

[Greg Kroah-Hartman]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tang Junhui <tang.junhui.linux@xxxxxxxxx>

commit 2e17a262a2371d38d2ec03614a2675a32cef9912 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 <tang.junhui.linux@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Coly Li <colyli@xxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/md/bcache/super.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1148,11 +1148,12 @@ int bch_cached_dev_attach(struct cached_
 	}
 
 	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);