1 files changed, 34 insertions, 7 deletions

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 738a0c24874f..8945aac31392 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -11,6 +11,7 @@
 #include <linux/flex_proportions.h>
 #include <linux/backing-dev-defs.h>
 #include <linux/blk_types.h>
+#include <linux/blk-cgroup.h>
 
 struct bio;
 
@@ -68,6 +69,17 @@ struct writeback_control {
 	unsigned for_reclaim:1;		/* Invoked from the page allocator */
 	unsigned range_cyclic:1;	/* range_start is cyclic */
 	unsigned for_sync:1;		/* sync(2) WB_SYNC_ALL writeback */
+
+	/*
+	 * When writeback IOs are bounced through async layers, only the
+	 * initial synchronous phase should be accounted towards inode
+	 * cgroup ownership arbitration to avoid confusion.  Later stages
+	 * can set the following flag to disable the accounting.
+	 */
+	unsigned no_cgroup_owner:1;
+
+	unsigned punt_to_cgroup:1;	/* cgrp punting, see __REQ_CGROUP_PUNT */
+
 #ifdef CONFIG_CGROUP_WRITEBACK
 	struct bdi_writeback *wb;	/* wb this writeback is issued under */
 	struct inode *inode;		/* inode being written out */
@@ -84,12 +96,27 @@ struct writeback_control {
 
 static inline int wbc_to_write_flags(struct writeback_control *wbc)
 {
+	int flags = 0;
+
+	if (wbc->punt_to_cgroup)
+		flags = REQ_CGROUP_PUNT;
+
 	if (wbc->sync_mode == WB_SYNC_ALL)
-		return REQ_SYNC;
+		flags |= REQ_SYNC;
 	else if (wbc->for_kupdate || wbc->for_background)
-		return REQ_BACKGROUND;
+		flags |= REQ_BACKGROUND;
 
-	return 0;
+	return flags;
+}
+
+static inline struct cgroup_subsys_state *
+wbc_blkcg_css(struct writeback_control *wbc)
+{
+#ifdef CONFIG_CGROUP_WRITEBACK
+	if (wbc->wb)
+		return wbc->wb->blkcg_css;
+#endif
+	return blkcg_root_css;
 }
 
 /*
@@ -188,8 +215,8 @@ void wbc_attach_and_unlock_inode(struct writeback_control *wbc,
 				 struct inode *inode)
 	__releases(&inode->i_lock);
 void wbc_detach_inode(struct writeback_control *wbc);
-void wbc_account_io(struct writeback_control *wbc, struct page *page,
-		    size_t bytes);
+void wbc_account_cgroup_owner(struct writeback_control *wbc, struct page *page,
+			      size_t bytes);
 void cgroup_writeback_umount(void);
 
 /**
@@ -291,8 +318,8 @@ static inline void wbc_init_bio(struct writeback_control *wbc, struct bio *bio)
 {
 }
 
-static inline void wbc_account_io(struct writeback_control *wbc,
-				  struct page *page, size_t bytes)
+static inline void wbc_account_cgroup_owner(struct writeback_control *wbc,
+					    struct page *page, size_t bytes)
 {
 }