From 21c6321fbb3a3787af07f1bc031d713a707fb69c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 May 2015 14:50:49 -0400 Subject: writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb() Currently, majority of cgroup writeback support including all the above functions are implemented in include/linux/backing-dev.h and mm/backing-dev.c; however, the portion closely related to writeback logic implemented in include/linux/writeback.h and mm/page-writeback.c will expand to support foreign writeback detection and correction. This patch moves wb[_try]_get() and wb_put() to include/linux/backing-dev-defs.h so that they can be used from writeback.h and inode_{attach|detach}_wb() to writeback.h and page-writeback.c. This is pure reorganization and doesn't introduce any functional changes. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Jan Kara Cc: Wu Fengguang Cc: Greg Thelen Signed-off-by: Jens Axboe --- include/linux/backing-dev-defs.h | 50 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'include/linux/backing-dev-defs.h') diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index 8d470b73824f..e047b496a0b9 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -186,4 +186,54 @@ static inline void set_bdi_congested(struct backing_dev_info *bdi, int sync) set_wb_congested(bdi->wb.congested, sync); } +#ifdef CONFIG_CGROUP_WRITEBACK + +/** + * wb_tryget - try to increment a wb's refcount + * @wb: bdi_writeback to get + */ +static inline bool wb_tryget(struct bdi_writeback *wb) +{ + if (wb != &wb->bdi->wb) + return percpu_ref_tryget(&wb->refcnt); + return true; +} + +/** + * wb_get - increment a wb's refcount + * @wb: bdi_writeback to get + */ +static inline void wb_get(struct bdi_writeback *wb) +{ + if (wb != &wb->bdi->wb) + percpu_ref_get(&wb->refcnt); +} + +/** + * wb_put - decrement a wb's refcount + * @wb: bdi_writeback to put + */ +static inline void wb_put(struct bdi_writeback *wb) +{ + if (wb != &wb->bdi->wb) + percpu_ref_put(&wb->refcnt); +} + +#else /* CONFIG_CGROUP_WRITEBACK */ + +static inline bool wb_tryget(struct bdi_writeback *wb) +{ + return true; +} + +static inline void wb_get(struct bdi_writeback *wb) +{ +} + +static inline void wb_put(struct bdi_writeback *wb) +{ +} + +#endif /* CONFIG_CGROUP_WRITEBACK */ + #endif /* __LINUX_BACKING_DEV_DEFS_H */ -- cgit v1.2.3