Merge branch 'for-3.5' of ../cgroup into block/for-3.5/core-merged

cgroup/for-3.5 contains the following changes which blk-cgroup needs
to proceed with the on-going cleanup.

* Dynamic addition and removal of cftypes to make config/stat file
  handling modular for policies.

* cgroup removal update to not wait for css references to drain to fix
  blkcg removal hang caused by cfq caching cfqgs.

Pull in cgroup/for-3.5 into block/for-3.5/core.  This causes the
following conflicts in block/blk-cgroup.c.

* 761b3ef50e "cgroup: remove cgroup_subsys argument from callbacks"
  conflicts with blkiocg_pre_destroy() addition and blkiocg_attach()
  removal.  Resolved by removing @subsys from all subsys methods.

* 676f7c8f84 "cgroup: relocate cftype and cgroup_subsys definitions in
  controllers" conflicts with ->pre_destroy() and ->attach() updates
  and removal of modular config.  Resolved by dropping forward
  declarations of the methods and applying updates to the relocated
  blkio_subsys.

* 4baf6e3325 "cgroup: convert all non-memcg controllers to the new
  cftype interface" builds upon the previous item.  Resolved by adding
  ->base_cftypes to the relocated blkio_subsys.

Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 11 insertions, 11 deletions

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index e66e9b63261..1a91efa6d12 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -17,7 +17,8 @@
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/kobject.h>
-#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/kmod.h>
 #include <linux/slab.h>
 #include <linux/user_namespace.h>
 #include <linux/socket.h>
@@ -29,16 +30,17 @@
 
 u64 uevent_seqnum;
 char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
-static DEFINE_SPINLOCK(sequence_lock);
 #ifdef CONFIG_NET
 struct uevent_sock {
 	struct list_head list;
 	struct sock *sk;
 };
 static LIST_HEAD(uevent_sock_list);
-static DEFINE_MUTEX(uevent_sock_mutex);
 #endif
 
+/* This lock protects uevent_seqnum and uevent_sock_list */
+static DEFINE_MUTEX(uevent_sock_mutex);
+
 /* the strings here must match the enum in include/linux/kobject.h */
 static const char *kobject_actions[] = {
 	[KOBJ_ADD] =		"add",
@@ -136,7 +138,6 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 	struct kobject *top_kobj;
 	struct kset *kset;
 	const struct kset_uevent_ops *uevent_ops;
-	u64 seq;
 	int i = 0;
 	int retval = 0;
 #ifdef CONFIG_NET
@@ -243,17 +244,16 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 	else if (action == KOBJ_REMOVE)
 		kobj->state_remove_uevent_sent = 1;
 
+	mutex_lock(&uevent_sock_mutex);
 	/* we will send an event, so request a new sequence number */
-	spin_lock(&sequence_lock);
-	seq = ++uevent_seqnum;
-	spin_unlock(&sequence_lock);
-	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);
-	if (retval)
+	retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
+	if (retval) {
+		mutex_unlock(&uevent_sock_mutex);
 		goto exit;
+	}
 
 #if defined(CONFIG_NET)
 	/* send netlink message */
-	mutex_lock(&uevent_sock_mutex);
 	list_for_each_entry(ue_sk, &uevent_sock_list, list) {
 		struct sock *uevent_sock = ue_sk->sk;
 		struct sk_buff *skb;
@@ -290,8 +290,8 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 		} else
 			retval = -ENOMEM;
 	}
-	mutex_unlock(&uevent_sock_mutex);
 #endif
+	mutex_unlock(&uevent_sock_mutex);
 
 	/* call uevent_helper, usually only enabled during early boot */
 	if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {