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authorTejun Heo <tj@kernel.org>2015-05-28 21:50:49 +0300
committerJens Axboe <axboe@fb.com>2015-06-02 17:39:08 +0300
commit21c6321fbb3a3787af07f1bc031d713a707fb69c (patch)
treede5489853b7f0d82adfd74da30d3945aba45e366 /include/linux/backing-dev-defs.h
parent97c9341f727105c29478da19f1687b0e0a917256 (diff)
downloadlinux-21c6321fbb3a3787af07f1bc031d713a707fb69c.tar.xz
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 <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Greg Thelen <gthelen@google.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux/backing-dev-defs.h')
-rw-r--r--include/linux/backing-dev-defs.h50
1 files changed, 50 insertions, 0 deletions
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 */