BCACHE_DEV_WB_RUNNING
if (test_and_clear_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags))
if (test_and_clear_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags))
(!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)))
WARN_ON(test_and_clear_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags));
WARN_ON(test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags));
if (!test_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags) ||
if (test_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags) &&