threadgroup: rename signal->threadgroup_fork_lock to ->group_rwsem

Make the following renames to prepare for extension of threadgroup
locking.

* s/signal->threadgroup_fork_lock/signal->group_rwsem/
* s/threadgroup_fork_read_lock()/threadgroup_change_begin()/
* s/threadgroup_fork_read_unlock()/threadgroup_change_end()/
* s/threadgroup_fork_write_lock()/threadgroup_lock()/
* s/threadgroup_fork_write_unlock()/threadgroup_unlock()/

This patch doesn't cause any behavior change.

-v2: Rename threadgroup_change_done() to threadgroup_change_end() per
     KAMEZAWA's suggestion.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Menage <paul@paulmenage.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 827808613847..d4ac9e3e0075 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -972,7 +972,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 	sched_autogroup_fork(sig);
 
 #ifdef CONFIG_CGROUPS
-	init_rwsem(&sig->threadgroup_fork_lock);
+	init_rwsem(&sig->group_rwsem);
 #endif
 
 	sig->oom_adj = current->signal->oom_adj;
@@ -1157,7 +1157,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	p->io_context = NULL;
 	p->audit_context = NULL;
 	if (clone_flags & CLONE_THREAD)
-		threadgroup_fork_read_lock(current);
+		threadgroup_change_begin(current);
 	cgroup_fork(p);
 #ifdef CONFIG_NUMA
 	p->mempolicy = mpol_dup(p->mempolicy);
@@ -1372,7 +1372,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	proc_fork_connector(p);
 	cgroup_post_fork(p);
 	if (clone_flags & CLONE_THREAD)
-		threadgroup_fork_read_unlock(current);
+		threadgroup_change_end(current);
 	perf_event_fork(p);
 	return p;
 
@@ -1407,7 +1407,7 @@ bad_fork_cleanup_policy:
 bad_fork_cleanup_cgroup:
 #endif
 	if (clone_flags & CLONE_THREAD)
-		threadgroup_fork_read_unlock(current);
+		threadgroup_change_end(current);
 	cgroup_exit(p, cgroup_callbacks_done);
 	delayacct_tsk_free(p);
 	module_put(task_thread_info(p)->exec_domain->module);