Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block

[karo-tx-linux.git] / include / linux / blk-cgroup.h

diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 07a32b813ed897d2610fc4abcc205dc6f5f0f0af..58cfab80dd707ff28d8b4e12fdf735bc24f7f60b 100644 (file)
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -23,11 +23,6 @@
 /* Max limits for throttle policy */
 #define THROTL_IOPS_MAX                UINT_MAX
 
-/* CFQ specific, out here for blkcg->cfq_weight */
-#define CFQ_WEIGHT_MIN         10
-#define CFQ_WEIGHT_MAX         1000
-#define CFQ_WEIGHT_DEFAULT     500
-
 #ifdef CONFIG_BLK_CGROUP
 
 enum blkg_rwstat_type {
@@ -50,9 +45,7 @@ struct blkcg {
        struct blkcg_gq                 *blkg_hint;
        struct hlist_head               blkg_list;
 
-       /* TODO: per-policy storage in blkcg */
-       unsigned int                    cfq_weight;     /* belongs to cfq */
-       unsigned int                    cfq_leaf_weight;
+       struct blkcg_policy_data        *pd[BLKCG_MAX_POLS];
 
 #ifdef CONFIG_CGROUP_WRITEBACK
        struct list_head                cgwb_list;
@@ -91,6 +84,24 @@ struct blkg_policy_data {
        struct list_head                alloc_node;
 };
 
+/*
+ * Policies that need to keep per-blkcg data which is independent
+ * from any request_queue associated to it must specify its size
+ * with the cpd_size field of the blkcg_policy structure and
+ * embed a blkcg_policy_data in it. blkcg core allocates
+ * policy-specific per-blkcg structures lazily the first time
+ * they are actually needed, so it handles them together with
+ * blkgs. cpd_init() is invoked to let each policy handle
+ * per-blkcg data.
+ */
+struct blkcg_policy_data {
+       /* the policy id this per-policy data belongs to */
+       int                             plid;
+
+       /* used during policy activation */
+       struct list_head                alloc_node;
+};
+
 /* association between a blk cgroup and a request queue */
 struct blkcg_gq {
        /* Pointer to the associated request_queue */
@@ -122,6 +133,7 @@ struct blkcg_gq {
        struct rcu_head                 rcu_head;
 };
 
+typedef void (blkcg_pol_init_cpd_fn)(const struct blkcg *blkcg);
 typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);
 typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg);
 typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg);
@@ -132,10 +144,13 @@ struct blkcg_policy {
        int                             plid;
        /* policy specific private data size */
        size_t                          pd_size;
+       /* policy specific per-blkcg data size */
+       size_t                          cpd_size;
        /* cgroup files for the policy */
        struct cftype                   *cftypes;
 
        /* operations */
+       blkcg_pol_init_cpd_fn           *cpd_init_fn;
        blkcg_pol_init_pd_fn            *pd_init_fn;
        blkcg_pol_online_pd_fn          *pd_online_fn;
        blkcg_pol_offline_pd_fn         *pd_offline_fn;
@@ -235,6 +250,12 @@ static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
        return blkg ? blkg->pd[pol->plid] : NULL;
 }
 
+static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg,
+                                                    struct blkcg_policy *pol)
+{
+       return blkcg ? blkcg->pd[pol->plid] : NULL;
+}
+
 /**
  * pdata_to_blkg - get blkg associated with policy private data
  * @pd: policy private data of interest
@@ -581,6 +602,9 @@ struct blkcg {
 struct blkg_policy_data {
 };
 
+struct blkcg_policy_data {
+};
+
 struct blkcg_gq {
 };