Merge branches 'x86-ras-for-linus', 'x86-uv-for-linus' and 'x86-vdso-for-linus' of...

[cascardo/linux.git] / block / blk-cgroup.c

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b9f4cc4..e17da94 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -872,6 +872,13 @@ 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 +928,15 @@ 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 +1128,8 @@ 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);