Merge tag 'sunxi-fixes-for-4.3' of https://git.kernel.org/pub/scm/linux/kernel/git...

[linux-drm-fsl-dcu.git] / include / linux / backing-dev.h

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 0fe9df983ab7410c67143ecdc7a26bac958b4597..d5eb4ad1c534a8074b64ee75d4b597563e36e89a 100644 (file)
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 #include <linux/blkdev.h>
 #include <linux/writeback.h>
+#include <linux/memcontrol.h>
 #include <linux/blk-cgroup.h>
 #include <linux/backing-dev-defs.h>
 #include <linux/slab.h>
@@ -252,13 +253,19 @@ int inode_congested(struct inode *inode, int cong_bits);
  * @inode: inode of interest
  *
  * cgroup writeback requires support from both the bdi and filesystem.
- * Test whether @inode has both.
+ * Also, both memcg and iocg have to be on the default hierarchy.  Test
+ * whether all conditions are met.
+ *
+ * Note that the test result may change dynamically on the same inode
+ * depending on how memcg and iocg are configured.
  */
 static inline bool inode_cgwb_enabled(struct inode *inode)
 {
        struct backing_dev_info *bdi = inode_to_bdi(inode);
 
-       return bdi_cap_account_dirty(bdi) &&
+       return cgroup_on_dfl(mem_cgroup_root_css->cgroup) &&
+               cgroup_on_dfl(blkcg_root_css->cgroup) &&
+               bdi_cap_account_dirty(bdi) &&
                (bdi->capabilities & BDI_CAP_CGROUP_WRITEBACK) &&
                (inode->i_sb->s_iflags & SB_I_CGROUPWB);
 }
@@ -286,7 +293,7 @@ static inline struct bdi_writeback *wb_find_current(struct backing_dev_info *bdi
         * %current's blkcg equals the effective blkcg of its memcg.  No
         * need to use the relatively expensive cgroup_get_e_css().
         */
-       if (likely(wb && wb->blkcg_css == task_css(current, blkio_cgrp_id)))
+       if (likely(wb && wb->blkcg_css == task_css(current, io_cgrp_id)))
                return wb;
        return NULL;
 }
@@ -402,7 +409,7 @@ static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked)
 }
 
 struct wb_iter {
-       int                     start_blkcg_id;
+       int                     start_memcg_id;
        struct radix_tree_iter  tree_iter;
        void                    **slot;
 };
@@ -414,9 +421,9 @@ static inline struct bdi_writeback *__wb_iter_next(struct wb_iter *iter,
 
        WARN_ON_ONCE(!rcu_read_lock_held());
 
-       if (iter->start_blkcg_id >= 0) {
-               iter->slot = radix_tree_iter_init(titer, iter->start_blkcg_id);
-               iter->start_blkcg_id = -1;
+       if (iter->start_memcg_id >= 0) {
+               iter->slot = radix_tree_iter_init(titer, iter->start_memcg_id);
+               iter->start_memcg_id = -1;
        } else {
                iter->slot = radix_tree_next_slot(iter->slot, titer, 0);
        }
@@ -430,30 +437,30 @@ static inline struct bdi_writeback *__wb_iter_next(struct wb_iter *iter,
 
 static inline struct bdi_writeback *__wb_iter_init(struct wb_iter *iter,
                                                   struct backing_dev_info *bdi,
-                                                  int start_blkcg_id)
+                                                  int start_memcg_id)
 {
-       iter->start_blkcg_id = start_blkcg_id;
+       iter->start_memcg_id = start_memcg_id;
 
-       if (start_blkcg_id)
+       if (start_memcg_id)
                return __wb_iter_next(iter, bdi);
        else
                return &bdi->wb;
 }
 
 /**
- * bdi_for_each_wb - walk all wb's of a bdi in ascending blkcg ID order
+ * bdi_for_each_wb - walk all wb's of a bdi in ascending memcg ID order
  * @wb_cur: cursor struct bdi_writeback pointer
  * @bdi: bdi to walk wb's of
  * @iter: pointer to struct wb_iter to be used as iteration buffer
- * @start_blkcg_id: blkcg ID to start iteration from
+ * @start_memcg_id: memcg ID to start iteration from
  *
  * Iterate @wb_cur through the wb's (bdi_writeback's) of @bdi in ascending
- * blkcg ID order starting from @start_blkcg_id.  @iter is struct wb_iter
+ * memcg ID order starting from @start_memcg_id.  @iter is struct wb_iter
  * to be used as temp storage during iteration.  rcu_read_lock() must be
  * held throughout iteration.
  */
-#define bdi_for_each_wb(wb_cur, bdi, iter, start_blkcg_id)             \
-       for ((wb_cur) = __wb_iter_init(iter, bdi, start_blkcg_id);      \
+#define bdi_for_each_wb(wb_cur, bdi, iter, start_memcg_id)             \
+       for ((wb_cur) = __wb_iter_init(iter, bdi, start_memcg_id);      \
             (wb_cur); (wb_cur) = __wb_iter_next(iter, bdi))
 
 #else  /* CONFIG_CGROUP_WRITEBACK */