Merge branch 'stable-3.18' of git://git.infradead.org/users/pcmoore/selinux into...

[firefly-linux-kernel-4.4.55.git] / block / blk-cgroup.c

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b9f4cc494ecefbf2560483bdc4685bb98d59b5d3..0ac817b750dbc7a15f0c69c21ed184d5882e1696 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -822,7 +822,6 @@ static void blkcg_css_free(struct cgroup_subsys_state *css)
 static struct cgroup_subsys_state *
 blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
 {
-       static atomic64_t id_seq = ATOMIC64_INIT(0);
        struct blkcg *blkcg;
 
        if (!parent_css) {
@@ -836,7 +835,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
 
        blkcg->cfq_weight = CFQ_WEIGHT_DEFAULT;
        blkcg->cfq_leaf_weight = CFQ_WEIGHT_DEFAULT;
-       blkcg->id = atomic64_inc_return(&id_seq); /* root is 0, start from 1 */
 done:
        spin_lock_init(&blkcg->lock);
        INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_ATOMIC);
@@ -872,6 +870,13 @@ void blkcg_drain_queue(struct request_queue *q)
 {
        lockdep_assert_held(q->queue_lock);
 
+       /*
+        * @q could be exiting and already have destroyed all blkgs as
+        * indicated by NULL root_blkg.  If so, don't confuse policies.
+        */
+       if (!q->root_blkg)
+               return;
+
        blk_throtl_drain(q);
 }
 
@@ -921,7 +926,15 @@ struct cgroup_subsys blkio_cgrp_subsys = {
        .css_offline = blkcg_css_offline,
        .css_free = blkcg_css_free,
        .can_attach = blkcg_can_attach,
-       .base_cftypes = blkcg_files,
+       .legacy_cftypes = blkcg_files,
+#ifdef CONFIG_MEMCG
+       /*
+        * This ensures that, if available, memcg is automatically enabled
+        * together on the default hierarchy so that the owner cgroup can
+        * be retrieved from writeback pages.
+        */
+       .depends_on = 1 << memory_cgrp_id,
+#endif
 };
 EXPORT_SYMBOL_GPL(blkio_cgrp_subsys);
 
@@ -1113,7 +1126,8 @@ int blkcg_policy_register(struct blkcg_policy *pol)
 
        /* everything is in place, add intf files for the new policy */
        if (pol->cftypes)
-               WARN_ON(cgroup_add_cftypes(&blkio_cgrp_subsys, pol->cftypes));
+               WARN_ON(cgroup_add_legacy_cftypes(&blkio_cgrp_subsys,
+                                                 pol->cftypes));
        ret = 0;
 out_unlock:
        mutex_unlock(&blkcg_pol_mutex);