Commit 3f33e64f authored by Tejun Heo's avatar Tejun Heo
Browse files

Merge branch 'for-3.10-fixes' into for-3.11 



Merging to receive 7805d000 ("cgroup: fix a subtle bug in descendant
pre-order walk") so that further iterator updates can build upon it.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parents 23958e72 7805d000

include/linux/cgroup.h

+1 −1
Original line number Diff line number Diff line
@@ -709,7 +709,7 @@ struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos); 
 *

 * If a subsystem synchronizes against the parent in its ->css_online() and

 * before starting iterating, and synchronizes against @pos on each

 * iteration, any descendant cgroup which finished ->css_offline() is

 * iteration, any descendant cgroup which finished ->css_online() is

 * guaranteed to be visible in the future iterations.

 *

 * In other words, the following guarantees that a descendant can't escape

kernel/cgroup.c

+8 −10
Original line number Diff line number Diff line
@@ -2736,13 +2736,14 @@ static int cgroup_add_file(struct cgroup *cgrp, struct cgroup_subsys *subsys, 
		goto out;

	}



	mode = cgroup_file_mode(cft);

	error = cgroup_create_file(dentry, mode | S_IFREG, cgrp->root->sb);

	if (!error) {

	cfe->type = (void *)cft;

	cfe->dentry = dentry;

	dentry->d_fsdata = cfe;

	simple_xattrs_init(&cfe->xattrs);



	mode = cgroup_file_mode(cft);

	error = cgroup_create_file(dentry, mode | S_IFREG, cgrp->root->sb);

	if (!error) {

		list_add_tail(&cfe->node, &parent->files);

		cfe = NULL;

	}
@@ -2990,11 +2991,8 @@ struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos, 
	WARN_ON_ONCE(!rcu_read_lock_held());



	/* if first iteration, pretend we just visited @cgroup */

	if (!pos) {

		if (list_empty(&cgroup->children))

			return NULL;

	if (!pos)

		pos = cgroup;

	}



	/* visit the first child if exists */

	next = list_first_or_null_rcu(&pos->children, struct cgroup, sibling);
@@ -3002,14 +3000,14 @@ struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos, 
		return next;



	/* no child, visit my or the closest ancestor's next sibling */

	do {

	while (pos != cgroup) {

		next = list_entry_rcu(pos->sibling.next, struct cgroup,

				      sibling);

		if (&next->sibling != &pos->parent->children)

			return next;



		pos = pos->parent;

	} while (pos != cgroup);

	}



	return NULL;

}