Currently, devcg::has_children() directly tests cgroup->children for list emptiness. The field is not a published field and scheduled to go away. In addition, the test isn't strictly correct as devcg should only care about children which are visible to userland.
This patch converts has_children() to use css_next_child() instead. The subtle incorrectness is noted and will be dealt with later. Signed-off-by: Tejun Heo <[email protected]> Cc: Aristeu Rozanski <[email protected]> Cc: Serge Hallyn <[email protected]> --- security/device_cgroup.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/security/device_cgroup.c b/security/device_cgroup.c index 3116015..75b4b18 100644 --- a/security/device_cgroup.c +++ b/security/device_cgroup.c @@ -477,9 +477,17 @@ static int propagate_exception(struct dev_cgroup *devcg_root, static inline bool has_children(struct dev_cgroup *devcgroup) { - struct cgroup *cgrp = devcgroup->css.cgroup; + bool ret; - return !list_empty(&cgrp->children); + /* + * FIXME: There may be lingering offline csses and this function + * may return %true when there isn't any userland-visible child + * which is incorrect for our purposes. + */ + rcu_read_lock(); + ret = css_next_child(NULL, &devcgroup->css); + rcu_read_unlock(); + return ret; } /* -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
