)]}'
{
  "commit": "90925d0bf41bca432b370e7a33aff65dddcc6531",
  "tree": "cbf5c5effb08219cf9f4904e690bae88902164bf",
  "parents": [
    "095bbe41f799195819a23d57ce2b011f10daeca2"
  ],
  "author": {
    "name": "Tejun Heo",
    "email": "tj@kernel.org",
    "time": "Tue May 06 16:03:03 2014 -0400"
  },
  "committer": {
    "name": "Tejun Heo",
    "email": "tj@kernel.org",
    "time": "Tue May 06 16:03:03 2014 -0400"
  },
  "message": "cgroup: remove cgroup_tree_mutex\n\ncgroup_tree_mutex was introduced to work around the circular\ndependency between cgroup_mutex and kernfs active protection - some\nkernfs file and directory operations needed cgroup_mutex putting\ncgroup_mutex under active protection but cgroup also needs to be able\nto access cgroup hierarchies and cftypes to determine which\nkernfs_nodes need to be removed.  cgroup_tree_mutex nested above both\ncgroup_mutex and kernfs active protection and used to protect the\nhierarchy and cftypes.  While this worked, it added a lot of double\nlockings and was generally cumbersome.\n\nkernfs provides a mechanism to opt out of active protection and cgroup\nwas already using it for removal and subtree_control.  There\u0027s no\nreason to mix both methods of avoiding circular locking dependency and\nthe preceding cgroup_kn_lock_live() changes applied it to all relevant\ncgroup kernfs operations making it unnecessary to nest cgroup_mutex\nunder kernfs active protection.  The previous patch reversed the\noriginal lock ordering and put cgroup_mutex above kernfs active\nprotection.\n\nAfter these changes, all cgroup_tree_mutex usages are now accompanied\nby cgroup_mutex making the former completely redundant.  This patch\nremoves cgroup_tree_mutex and all its usages.\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "601a35dfd0847037e3832e9acce79fad1cba04f5",
      "old_mode": 33188,
      "old_path": "kernel/cgroup.c",
      "new_id": "4f218f3785961f0363b671a0e62b91f6d69dc7c3",
      "new_mode": 33188,
      "new_path": "kernel/cgroup.c"
    }
  ]
}