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-rw-r--r--block/blk-cgroup.c51
1 files changed, 47 insertions, 4 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 63b31ebae6e2..f3b44a65fc7a 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -63,6 +63,7 @@ static void blkg_free(struct blkcg_gq *blkg)
kfree(pd);
}
+ blk_exit_rl(&blkg->rl);
kfree(blkg);
}
@@ -90,6 +91,13 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
blkg->blkcg = blkcg;
blkg->refcnt = 1;
+ /* root blkg uses @q->root_rl, init rl only for !root blkgs */
+ if (blkcg != &blkcg_root) {
+ if (blk_init_rl(&blkg->rl, q, gfp_mask))
+ goto err_free;
+ blkg->rl.blkg = blkg;
+ }
+
for (i = 0; i < BLKCG_MAX_POLS; i++) {
struct blkcg_policy *pol = blkcg_policy[i];
struct blkg_policy_data *pd;
@@ -99,10 +107,8 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
/* alloc per-policy data and attach it to blkg */
pd = kzalloc_node(pol->pd_size, gfp_mask, q->node);
- if (!pd) {
- blkg_free(blkg);
- return NULL;
- }
+ if (!pd)
+ goto err_free;
blkg->pd[i] = pd;
pd->blkg = blkg;
@@ -113,6 +119,10 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
}
return blkg;
+
+err_free:
+ blkg_free(blkg);
+ return NULL;
}
static struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg,
@@ -300,6 +310,38 @@ void __blkg_release(struct blkcg_gq *blkg)
}
EXPORT_SYMBOL_GPL(__blkg_release);
+/*
+ * The next function used by blk_queue_for_each_rl(). It's a bit tricky
+ * because the root blkg uses @q->root_rl instead of its own rl.
+ */
+struct request_list *__blk_queue_next_rl(struct request_list *rl,
+ struct request_queue *q)
+{
+ struct list_head *ent;
+ struct blkcg_gq *blkg;
+
+ /*
+ * Determine the current blkg list_head. The first entry is
+ * root_rl which is off @q->blkg_list and mapped to the head.
+ */
+ if (rl == &q->root_rl) {
+ ent = &q->blkg_list;
+ } else {
+ blkg = container_of(rl, struct blkcg_gq, rl);
+ ent = &blkg->q_node;
+ }
+
+ /* walk to the next list_head, skip root blkcg */
+ ent = ent->next;
+ if (ent == &q->root_blkg->q_node)
+ ent = ent->next;
+ if (ent == &q->blkg_list)
+ return NULL;
+
+ blkg = container_of(ent, struct blkcg_gq, q_node);
+ return &blkg->rl;
+}
+
static int blkcg_reset_stats(struct cgroup *cgroup, struct cftype *cftype,
u64 val)
{
@@ -750,6 +792,7 @@ int blkcg_activate_policy(struct request_queue *q,
goto out_unlock;
}
q->root_blkg = blkg;
+ q->root_rl.blkg = blkg;
list_for_each_entry(blkg, &q->blkg_list, q_node)
cnt++;