struct list_head b_dirty_time; /* time stamps are dirty */
spinlock_t list_lock; /* protects the b_* lists */
+ atomic_t writeback_inodes; /* number of inodes under writeback */
struct percpu_counter stat[NR_WB_STAT_ITEMS];
unsigned long congested; /* WB_[a]sync_congested flags */
spinlock_t work_lock; /* protects work_list & dwork scheduling */
struct list_head work_list;
struct delayed_work dwork; /* work item used for writeback */
+ struct delayed_work bw_dwork; /* work item used for bandwidth estimate */
unsigned long dirty_sleep; /* last wait */