cgroup: convert to idr_alloc()
Convert to the much saner new idr interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 888fba4..40e0df6 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -5320,7 +5320,7 @@
static struct css_id *get_new_cssid(struct cgroup_subsys *ss, int depth)
{
struct css_id *newid;
- int myid, error, size;
+ int ret, size;
BUG_ON(!ss->use_id);
@@ -5328,35 +5328,24 @@
newid = kzalloc(size, GFP_KERNEL);
if (!newid)
return ERR_PTR(-ENOMEM);
- /* get id */
- if (unlikely(!idr_pre_get(&ss->idr, GFP_KERNEL))) {
- error = -ENOMEM;
- goto err_out;
- }
+
+ idr_preload(GFP_KERNEL);
spin_lock(&ss->id_lock);
/* Don't use 0. allocates an ID of 1-65535 */
- error = idr_get_new_above(&ss->idr, newid, 1, &myid);
+ ret = idr_alloc(&ss->idr, newid, 1, CSS_ID_MAX + 1, GFP_NOWAIT);
spin_unlock(&ss->id_lock);
+ idr_preload_end();
/* Returns error when there are no free spaces for new ID.*/
- if (error) {
- error = -ENOSPC;
+ if (ret < 0)
goto err_out;
- }
- if (myid > CSS_ID_MAX)
- goto remove_idr;
- newid->id = myid;
+ newid->id = ret;
newid->depth = depth;
return newid;
-remove_idr:
- error = -ENOSPC;
- spin_lock(&ss->id_lock);
- idr_remove(&ss->idr, myid);
- spin_unlock(&ss->id_lock);
err_out:
kfree(newid);
- return ERR_PTR(error);
+ return ERR_PTR(ret);
}