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>
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 94b1e35..f4544b9 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -23,11 +23,10 @@
extern struct fs_struct init_fs;
#ifdef CONFIG_CGROUPS
-#define INIT_THREADGROUP_FORK_LOCK(sig) \
- .threadgroup_fork_lock = \
- __RWSEM_INITIALIZER(sig.threadgroup_fork_lock),
+#define INIT_GROUP_RWSEM(sig) \
+ .group_rwsem = __RWSEM_INITIALIZER(sig.group_rwsem),
#else
-#define INIT_THREADGROUP_FORK_LOCK(sig)
+#define INIT_GROUP_RWSEM(sig)
#endif
#define INIT_SIGNALS(sig) { \
@@ -46,7 +45,7 @@
}, \
.cred_guard_mutex = \
__MUTEX_INITIALIZER(sig.cred_guard_mutex), \
- INIT_THREADGROUP_FORK_LOCK(sig) \
+ INIT_GROUP_RWSEM(sig) \
}
extern struct nsproxy init_nsproxy;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index d81cce9..8cd5232 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -635,13 +635,13 @@
#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 @@
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
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 6545fd6..b409df3 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2003,8 +2003,8 @@
* @cgrp: the cgroup to attach to
* @leader: the threadgroup leader task_struct of the group to be attached
*
- * Call holding cgroup_mutex and the threadgroup_fork_lock of the leader. Will
- * take task_lock of each thread in leader's threadgroup individually in turn.
+ * Call holding cgroup_mutex and the group_rwsem of the leader. Will take
+ * task_lock of each thread in leader's threadgroup individually in turn.
*/
int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
{
@@ -2030,8 +2030,8 @@
* step 0: in order to do expensive, possibly blocking operations for
* every thread, we cannot iterate the thread group list, since it needs
* rcu or tasklist locked. instead, build an array of all threads in the
- * group - threadgroup_fork_lock prevents new threads from appearing,
- * and if threads exit, this will just be an over-estimate.
+ * group - group_rwsem prevents new threads from appearing, and if
+ * threads exit, this will just be an over-estimate.
*/
group_size = get_nr_threads(leader);
/* flex_array supports very large thread-groups better than kmalloc. */
@@ -2249,7 +2249,6 @@
cgroup_unlock();
return -ESRCH;
}
-
/*
* even if we're attaching all tasks in the thread group, we
* only need to check permissions on one of them.
@@ -2273,9 +2272,9 @@
}
if (threadgroup) {
- threadgroup_fork_write_lock(tsk);
+ threadgroup_lock(tsk);
ret = cgroup_attach_proc(cgrp, tsk);
- threadgroup_fork_write_unlock(tsk);
+ threadgroup_unlock(tsk);
} else {
ret = cgroup_attach_task(cgrp, tsk);
}
diff --git a/kernel/fork.c b/kernel/fork.c
index 8278086..d4ac9e3 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -972,7 +972,7 @@
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 @@
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 @@
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_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);
