[no subject]

[Tejun Heo]

cafe563591 ("bcache: A block layer cache") added a new cgroup
subsystem bcache_subsys without proper review and ack.  bcache_subsys
seems to use cgroup for group stats and per-group cache_mode
configuration.  This is very much the type of usage that we don't want
to allow.

Fortunately, CONFIG_CGROUP_BCACHE which enables bcache_subsys is
currently commented out, so this shouldn't have any upstream users.
Let's nip in the bud.  While at it, clarify in cgroup_subsys.h that no
new subsystem should be added without explicit acks from cgroup
maintainers.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Cc: cgroups@xxxxxxxxxxxxxxx
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: linux-bcache@xxxxxxxxxxxxxxx
---
Applied to cgroup/for-3.11-fixes.  Please don't do things like this
ever again.

Thanks.

 include/linux/cgroup_subsys.h | 45 +++++++------------------------------------
 1 file changed, 7 insertions(+), 38 deletions(-)

diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index 6e7ec64..b613ffd 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -1,86 +1,55 @@
-/* Add subsystem definitions of the form SUBSYS(<name>) in this
- * file. Surround each one by a line of comment markers so that
- * patches don't collide
+/*
+ * List of cgroup subsystems.
+ *
+ * DO NOT ADD ANY SUBSYSTEM WITHOUT EXPLICIT ACKS FROM CGROUP MAINTAINERS.
  */
-
-/* */
-
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_CPUSETS)
 SUBSYS(cpuset)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_CGROUP_DEBUG)
 SUBSYS(debug)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_CGROUP_SCHED)
 SUBSYS(cpu_cgroup)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_CGROUP_CPUACCT)
 SUBSYS(cpuacct)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_MEMCG)
 SUBSYS(mem_cgroup)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_CGROUP_DEVICE)
 SUBSYS(devices)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_CGROUP_FREEZER)
 SUBSYS(freezer)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_NET_CLS_CGROUP)
 SUBSYS(net_cls)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_BLK_CGROUP)
 SUBSYS(blkio)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_CGROUP_PERF)
 SUBSYS(perf)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_NETPRIO_CGROUP)
 SUBSYS(net_prio)
 #endif
 
-/* */
-
 #if IS_SUBSYS_ENABLED(CONFIG_CGROUP_HUGETLB)
 SUBSYS(hugetlb)
 #endif
-
-/* */
-
-#ifdef CONFIG_CGROUP_BCACHE
-SUBSYS(bcache)
-#endif
-
-/* */
+/*
+ * DO NOT ADD ANY SUBSYSTEM WITHOUT EXPLICIT ACKS FROM CGROUP MAINTAINERS.
+ */
-- 
1.8.3.1

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