cgroup: rename cgroup_pidlist->mutex

It's a rw_semaphore not a mutex.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Li Zefan 2013-08-01 09:52:15 +08:00 committed by Tejun Heo
parent 876ede8b2b
commit b395890a09

View file

@ -3436,7 +3436,7 @@ struct cgroup_pidlist {
/* pointer to the cgroup we belong to, for list removal purposes */
struct cgroup *owner;
/* protects the other fields */
struct rw_semaphore mutex;
struct rw_semaphore rwsem;
};
/*
@ -3509,7 +3509,7 @@ static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
struct pid_namespace *ns = task_active_pid_ns(current);
/*
* We can't drop the pidlist_mutex before taking the l->mutex in case
* We can't drop the pidlist_mutex before taking the l->rwsem in case
* the last ref-holder is trying to remove l from the list at the same
* time. Holding the pidlist_mutex precludes somebody taking whichever
* list we find out from under us - compare release_pid_array().
@ -3518,7 +3518,7 @@ static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
list_for_each_entry(l, &cgrp->pidlists, links) {
if (l->key.type == type && l->key.ns == ns) {
/* make sure l doesn't vanish out from under us */
down_write(&l->mutex);
down_write(&l->rwsem);
mutex_unlock(&cgrp->pidlist_mutex);
return l;
}
@ -3529,8 +3529,8 @@ static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
mutex_unlock(&cgrp->pidlist_mutex);
return l;
}
init_rwsem(&l->mutex);
down_write(&l->mutex);
init_rwsem(&l->rwsem);
down_write(&l->rwsem);
l->key.type = type;
l->key.ns = get_pid_ns(ns);
l->owner = cgrp;
@ -3591,7 +3591,7 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
l->list = array;
l->length = length;
l->use_count++;
up_write(&l->mutex);
up_write(&l->rwsem);
*lp = l;
return 0;
}
@ -3669,7 +3669,7 @@ static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
int index = 0, pid = *pos;
int *iter;
down_read(&l->mutex);
down_read(&l->rwsem);
if (pid) {
int end = l->length;
@ -3696,7 +3696,7 @@ static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
static void cgroup_pidlist_stop(struct seq_file *s, void *v)
{
struct cgroup_pidlist *l = s->private;
up_read(&l->mutex);
up_read(&l->rwsem);
}
static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
@ -3742,7 +3742,7 @@ static void cgroup_release_pid_array(struct cgroup_pidlist *l)
* pidlist_mutex, we have to take pidlist_mutex first.
*/
mutex_lock(&l->owner->pidlist_mutex);
down_write(&l->mutex);
down_write(&l->rwsem);
BUG_ON(!l->use_count);
if (!--l->use_count) {
/* we're the last user if refcount is 0; remove and free */
@ -3750,12 +3750,12 @@ static void cgroup_release_pid_array(struct cgroup_pidlist *l)
mutex_unlock(&l->owner->pidlist_mutex);
pidlist_free(l->list);
put_pid_ns(l->key.ns);
up_write(&l->mutex);
up_write(&l->rwsem);
kfree(l);
return;
}
mutex_unlock(&l->owner->pidlist_mutex);
up_write(&l->mutex);
up_write(&l->rwsem);
}
static int cgroup_pidlist_release(struct inode *inode, struct file *file)