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authorTejun Heo <tj@kernel.org>2013-08-02 16:12:13 -0400
committerTejun Heo <tj@kernel.org>2013-08-02 16:12:13 -0400
commit61584e3f4964995e575618f76ff7197123796e75 (patch)
treec43a31c30b23d5e576f2f52983cda804036ed389 /kernel/cgroup.c
parentb395890a092d8ecbe54f005179e3dec4b6bf752a (diff)
parentda0a12caffad2eeadea429f83818408e7b77379a (diff)
downloadlinux-61584e3f4964995e575618f76ff7197123796e75.tar.bz2
cgroup: Merge branch 'for-3.11-fixes' into for-3.12
for-3.12 branch is about to receive invasive updates which are dependent on da0a12caff ("cgroup: fix a leak when percpu_ref_init() fails"). Given the amount of scheduled changes, I think it'd less painful to pull in for-3.11-fixes as preparation. Pull in for-3.11-fixes into for-3.12. Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup.c')
-rw-r--r--kernel/cgroup.c35
1 files changed, 22 insertions, 13 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 9420662df87e..ae4c46834633 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1805,36 +1805,43 @@ out:
EXPORT_SYMBOL_GPL(cgroup_path);
/**
- * task_cgroup_path_from_hierarchy - cgroup path of a task on a hierarchy
+ * task_cgroup_path - cgroup path of a task in the first cgroup hierarchy
* @task: target task
- * @hierarchy_id: the hierarchy to look up @task's cgroup from
* @buf: the buffer to write the path into
* @buflen: the length of the buffer
*
- * Determine @task's cgroup on the hierarchy specified by @hierarchy_id and
- * copy its path into @buf. This function grabs cgroup_mutex and shouldn't
- * be used inside locks used by cgroup controller callbacks.
+ * Determine @task's cgroup on the first (the one with the lowest non-zero
+ * hierarchy_id) cgroup hierarchy and copy its path into @buf. This
+ * function grabs cgroup_mutex and shouldn't be used inside locks used by
+ * cgroup controller callbacks.
+ *
+ * Returns 0 on success, fails with -%ENAMETOOLONG if @buflen is too short.
*/
-int task_cgroup_path_from_hierarchy(struct task_struct *task, int hierarchy_id,
- char *buf, size_t buflen)
+int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
{
struct cgroupfs_root *root;
- struct cgroup *cgrp = NULL;
- int ret = -ENOENT;
+ struct cgroup *cgrp;
+ int hierarchy_id = 1, ret = 0;
+
+ if (buflen < 2)
+ return -ENAMETOOLONG;
mutex_lock(&cgroup_mutex);
- root = idr_find(&cgroup_hierarchy_idr, hierarchy_id);
+ root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id);
+
if (root) {
cgrp = task_cgroup_from_root(task, root);
ret = cgroup_path(cgrp, buf, buflen);
+ } else {
+ /* if no hierarchy exists, everyone is in "/" */
+ memcpy(buf, "/", 2);
}
mutex_unlock(&cgroup_mutex);
-
return ret;
}
-EXPORT_SYMBOL_GPL(task_cgroup_path_from_hierarchy);
+EXPORT_SYMBOL_GPL(task_cgroup_path);
/*
* Control Group taskset
@@ -4304,8 +4311,10 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
}
err = percpu_ref_init(&css->refcnt, css_release);
- if (err)
+ if (err) {
+ ss->css_free(cgrp);
goto err_free_all;
+ }
init_cgroup_css(css, ss, cgrp);