diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c index b280c134dd4d..4dbeaaa575bf 100644 --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -565,9 +565,15 @@ static int bch_writeback_thread(void *arg) while (!kthread_should_stop()) { down_write(&dc->writeback_lock); set_current_state(TASK_INTERRUPTIBLE); - if (!atomic_read(&dc->has_dirty) || - (!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) && - !dc->writeback_running)) { + /* + * If the bache device is detaching, skip here and continue + * to perform writeback. Otherwise, if no dirty data on cache, + * or there is dirty data on cache but writeback is disabled, + * the writeback thread should sleep here and wait for others + * to wake up it. + */ + if (!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) && + (!atomic_read(&dc->has_dirty) || !dc->writeback_running)) { up_write(&dc->writeback_lock); if (kthread_should_stop()) { @@ -587,6 +593,14 @@ static int bch_writeback_thread(void *arg) atomic_set(&dc->has_dirty, 0); SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN); bch_write_bdev_super(dc, NULL); + /* + * If bcache device is detaching via sysfs interface, + * writeback thread should stop after there is no dirty + * data on cache. BCACHE_DEV_DETACHING flag is set in + * bch_cached_dev_detach(). + */ + if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) + break; } up_write(&dc->writeback_lock);