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, 15 insertions, 15 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index d81cce933869..8cd523202a3b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -635,13 +635,13 @@ struct signal_struct {
 #endif
 #ifdef CONFIG_CGROUPS
         /*
-         * The threadgroup_fork_lock prevents threads from forking with
+         * The group_rwsem prevents threads from forking with
          * CLONE_THREAD while held for writing. Use this for fork-sensitive
          * threadgroup-wide operations. It's taken for reading in fork.c in
          * copy_process().
          * Currently only needed write-side by cgroups.
          */
-        struct rw_semaphore threadgroup_fork_lock;
+        struct rw_semaphore group_rwsem;
 #endif
 
         int oom_adj;            /* OOM kill score adjustment (bit shift) */
@@ -2371,29 +2371,29 @@ static inline void unlock_task_sighand(struct task_struct *tsk,
         spin_unlock_irqrestore(&tsk->sighand->siglock, *flags);
 }
 
-/* See the declaration of threadgroup_fork_lock in signal_struct. */
+/* See the declaration of group_rwsem in signal_struct. */
 #ifdef CONFIG_CGROUPS
-static inline void threadgroup_fork_read_lock(struct task_struct *tsk)
+static inline void threadgroup_change_begin(struct task_struct *tsk)
 {
-        down_read(&tsk->signal->threadgroup_fork_lock);
+        down_read(&tsk->signal->group_rwsem);
 }
-static inline void threadgroup_fork_read_unlock(struct task_struct *tsk)
+static inline void threadgroup_change_end(struct task_struct *tsk)
 {
-        up_read(&tsk->signal->threadgroup_fork_lock);
+        up_read(&tsk->signal->group_rwsem);
 }
-static inline void threadgroup_fork_write_lock(struct task_struct *tsk)
+static inline void threadgroup_lock(struct task_struct *tsk)
 {
-        down_write(&tsk->signal->threadgroup_fork_lock);
+        down_write(&tsk->signal->group_rwsem);
 }
-static inline void threadgroup_fork_write_unlock(struct task_struct *tsk)
+static inline void threadgroup_unlock(struct task_struct *tsk)
 {
-        up_write(&tsk->signal->threadgroup_fork_lock);
+        up_write(&tsk->signal->group_rwsem);
 }
 #else
-static inline void threadgroup_fork_read_lock(struct task_struct *tsk) {}
-static inline void threadgroup_fork_read_unlock(struct task_struct *tsk) {}
-static inline void threadgroup_fork_write_lock(struct task_struct *tsk) {}
-static inline void threadgroup_fork_write_unlock(struct task_struct *tsk) {}
+static inline void threadgroup_change_begin(struct task_struct *tsk) {}
+static inline void threadgroup_change_end(struct task_struct *tsk) {}
+static inline void threadgroup_lock(struct task_struct *tsk) {}
+static inline void threadgroup_unlock(struct task_struct *tsk) {}
 #endif
 
 #ifndef __HAVE_THREAD_FUNCTIONS