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>

1 files changed, 0 insertions, 82 deletions

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index e9d7373f5f93..5c978a924157 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -243,7 +243,6 @@ void wb_congested_put(struct bdi_writeback_congested *congested);
 struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi,
 				    struct cgroup_subsys_state *memcg_css,
 				    gfp_t gfp);
-void __inode_attach_wb(struct inode *inode, struct page *page);
 void wb_memcg_offline(struct mem_cgroup *memcg);
 void wb_blkcg_offline(struct blkcg *blkcg);
 int inode_congested(struct inode *inode, int cong_bits);
@@ -265,37 +264,6 @@ static inline bool inode_cgwb_enabled(struct inode *inode)
 }
 
 /**
- * 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);
-}
-
-/**
  * wb_find_current - find wb for %current on a bdi
  * @bdi: bdi of interest
  *
@@ -354,35 +322,6 @@ wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp)
 }
 
 /**
- * inode_attach_wb - associate an inode with its wb
- * @inode: inode of interest
- * @page: page being dirtied (may be NULL)
- *
- * If @inode doesn't have its wb, associate it with the wb matching the
- * memcg of @page or, if @page is NULL, %current.  May be called w/ or w/o
- * @inode->i_lock.
- */
-static inline void inode_attach_wb(struct inode *inode, struct page *page)
-{
-	if (!inode->i_wb)
-		__inode_attach_wb(inode, page);
-}
-
-/**
- * inode_detach_wb - disassociate an inode from its wb
- * @inode: inode of interest
- *
- * @inode is being freed.  Detach from its wb.
- */
-static inline void inode_detach_wb(struct inode *inode)
-{
-	if (inode->i_wb) {
-		wb_put(inode->i_wb);
-		inode->i_wb = NULL;
-	}
-}
-
-/**
  * inode_to_wb - determine the wb of an inode
  * @inode: inode of interest
  *
@@ -471,19 +410,6 @@ static inline void wb_congested_put(struct bdi_writeback_congested *congested)
 {
 }
 
-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)
-{
-}
-
 static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi)
 {
 	return &bdi->wb;
@@ -495,14 +421,6 @@ wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp)
 	return &bdi->wb;
 }
 
-static inline void inode_attach_wb(struct inode *inode, struct page *page)
-{
-}
-
-static inline void inode_detach_wb(struct inode *inode)
-{
-}
-
 static inline struct bdi_writeback *inode_to_wb(struct inode *inode)
 {
 	return &inode_to_bdi(inode)->wb;