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authorTejun Heo <tj@kernel.org>2015-05-28 14:50:49 -0400
committerJens Axboe <axboe@fb.com>2015-06-02 08:39:08 -0600
commit21c6321fbb3a3787af07f1bc031d713a707fb69c (patch)
treede5489853b7f0d82adfd74da30d3945aba45e366 /include/linux/writeback.h
parent97c9341f727105c29478da19f1687b0e0a917256 (diff)
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/writeback.h')
-rw-r--r--include/linux/writeback.h46
1 files changed, 46 insertions, 0 deletions
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 3b73e97ecfc7..6726b7e56beb 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -8,6 +8,7 @@
#include <linux/workqueue.h>
#include <linux/fs.h>
#include <linux/flex_proportions.h>
+#include <linux/backing-dev-defs.h>
DECLARE_PER_CPU(int, dirty_throttle_leaks);
@@ -173,6 +174,51 @@ static inline void wait_on_inode(struct inode *inode)
wait_on_bit(&inode->i_state, __I_NEW, TASK_UNINTERRUPTIBLE);
}
+#ifdef CONFIG_CGROUP_WRITEBACK
+
+void __inode_attach_wb(struct inode *inode, struct page *page);
+
+/**
+ * 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;
+ }
+}
+
+#else /* CONFIG_CGROUP_WRITEBACK */
+
+static inline void inode_attach_wb(struct inode *inode, struct page *page)
+{
+}
+
+static inline void inode_detach_wb(struct inode *inode)
+{
+}
+
+#endif /* CONFIG_CGROUP_WRITEBACK */
+
/*
* mm/page-writeback.c
*/