blkcg: remove unnecessary blkcg_root handling from css_alloc/free paths
blkcg_css_alloc() bypasses policy data allocation and blkcg_css_free()
bypasses policy data and blkcg freeing for blkcg_root. There's no
reason to to treat policy data any differently for blkcg_root. If the
root css gets allocated after policies are registered, policy
registration path will add policy data; otherwise, the alloc path
will. The free path isn't never invoked for root csses.
This patch removes the unnecessary special handling of blkcg_root from
css_alloc/free paths.
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 cd25183..f91a4e0 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -823,18 +823,15 @@
static void blkcg_css_free(struct cgroup_subsys_state *css)
{
struct blkcg *blkcg = css_to_blkcg(css);
+ int i;
mutex_lock(&blkcg_pol_mutex);
list_del(&blkcg->all_blkcgs_node);
mutex_unlock(&blkcg_pol_mutex);
- if (blkcg != &blkcg_root) {
- int i;
-
- for (i = 0; i < BLKCG_MAX_POLS; i++)
- kfree(blkcg->pd[i]);
- kfree(blkcg);
- }
+ for (i = 0; i < BLKCG_MAX_POLS; i++)
+ kfree(blkcg->pd[i]);
+ kfree(blkcg);
}
static struct cgroup_subsys_state *
@@ -848,13 +845,12 @@
if (!parent_css) {
blkcg = &blkcg_root;
- goto done;
- }
-
- blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
- if (!blkcg) {
- ret = ERR_PTR(-ENOMEM);
- goto free_blkcg;
+ } else {
+ blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
+ if (!blkcg) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_blkcg;
+ }
}
for (i = 0; i < BLKCG_MAX_POLS ; i++) {
@@ -881,7 +877,6 @@
pol->cpd_init_fn(blkcg);
}
-done:
spin_lock_init(&blkcg->lock);
INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT);
INIT_HLIST_HEAD(&blkcg->blkg_list);
