blkcg: make blkg_[rw]stat_recursive_sum() to be able to index into blkcg_gq
Currently, blkg_[rw]stat_recursive_sum() assume that the target
counter is located in pd (blkg_policy_data); however, some counters
are planned to be moved to blkg (blkcg_gq).
This patch updates blkg_[rw]stat_recursive_sum() to take blkg and
blkg_policy pointers instead of pd. If policy is NULL, it indexes
into blkg. If non-NULL, into the blkg's pd of the policy.
The existing usages are updated to maintain the current behaviors.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 02a2d02..b263207 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -581,30 +581,39 @@
/**
* blkg_stat_recursive_sum - collect hierarchical blkg_stat
- * @pd: policy private data of interest
- * @off: offset to the blkg_stat in @pd
+ * @blkg: blkg of interest
+ * @pol: blkcg_policy which contains the blkg_stat
+ * @off: offset to the blkg_stat in blkg_policy_data or @blkg
*
- * Collect the blkg_stat specified by @off from @pd and all its online
- * descendants and their aux counts. The caller must be holding the queue
- * lock for online tests.
+ * Collect the blkg_stat specified by @blkg, @pol and @off and all its
+ * online descendants and their aux counts. The caller must be holding the
+ * queue lock for online tests.
+ *
+ * If @pol is NULL, blkg_stat is at @off bytes into @blkg; otherwise, it is
+ * at @off bytes into @blkg's blkg_policy_data of the policy.
*/
-u64 blkg_stat_recursive_sum(struct blkg_policy_data *pd, int off)
+u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg,
+ struct blkcg_policy *pol, int off)
{
- struct blkcg_policy *pol = blkcg_policy[pd->plid];
struct blkcg_gq *pos_blkg;
struct cgroup_subsys_state *pos_css;
u64 sum = 0;
- lockdep_assert_held(pd->blkg->q->queue_lock);
+ lockdep_assert_held(blkg->q->queue_lock);
rcu_read_lock();
- blkg_for_each_descendant_pre(pos_blkg, pos_css, pd_to_blkg(pd)) {
- struct blkg_policy_data *pos_pd = blkg_to_pd(pos_blkg, pol);
- struct blkg_stat *stat = (void *)pos_pd + off;
+ blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
+ struct blkg_stat *stat;
- if (pos_blkg->online)
- sum += blkg_stat_read(stat) +
- atomic64_read(&stat->aux_cnt);
+ if (!pos_blkg->online)
+ continue;
+
+ if (pol)
+ stat = (void *)blkg_to_pd(pos_blkg, pol) + off;
+ else
+ stat = (void *)blkg + off;
+
+ sum += blkg_stat_read(stat) + atomic64_read(&stat->aux_cnt);
}
rcu_read_unlock();
@@ -614,33 +623,39 @@
/**
* blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat
- * @pd: policy private data of interest
- * @off: offset to the blkg_stat in @pd
+ * @blkg: blkg of interest
+ * @pol: blkcg_policy which contains the blkg_rwstat
+ * @off: offset to the blkg_rwstat in blkg_policy_data or @blkg
*
- * Collect the blkg_rwstat specified by @off from @pd and all its online
- * descendants and their aux counts. The caller must be holding the queue
- * lock for online tests.
+ * Collect the blkg_rwstat specified by @blkg, @pol and @off and all its
+ * online descendants and their aux counts. The caller must be holding the
+ * queue lock for online tests.
+ *
+ * If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it
+ * is at @off bytes into @blkg's blkg_policy_data of the policy.
*/
-struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkg_policy_data *pd,
- int off)
+struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,
+ struct blkcg_policy *pol, int off)
{
- struct blkcg_policy *pol = blkcg_policy[pd->plid];
struct blkcg_gq *pos_blkg;
struct cgroup_subsys_state *pos_css;
struct blkg_rwstat sum = { };
int i;
- lockdep_assert_held(pd->blkg->q->queue_lock);
+ lockdep_assert_held(blkg->q->queue_lock);
rcu_read_lock();
- blkg_for_each_descendant_pre(pos_blkg, pos_css, pd_to_blkg(pd)) {
- struct blkg_policy_data *pos_pd = blkg_to_pd(pos_blkg, pol);
- struct blkg_rwstat *rwstat = (void *)pos_pd + off;
- struct blkg_rwstat tmp;
+ blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
+ struct blkg_rwstat *rwstat, tmp;
if (!pos_blkg->online)
continue;
+ if (pol)
+ rwstat = (void *)blkg_to_pd(pos_blkg, pol) + off;
+ else
+ rwstat = (void *)pos_blkg + off;
+
tmp = blkg_rwstat_read(rwstat);
for (i = 0; i < BLKG_RWSTAT_NR; i++)