path: root/kernel
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authorMichael S. Tsirkin <mst@redhat.com>2010-09-09 16:37:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-09-09 18:57:23 -0700
commit31583bb0cf6cc40f2a468a4d2f3b9cbefd24f891 (patch)
tree1c9ff4ff83ef80fe0b9b5d6fa7ec9af1ebbc2209 /kernel
parented430fec756ad65f7cfba24f8ad17c3d5a403290 (diff)
cgroups: fix API thinko
Add cgroup_attach_task_all() The existing cgroup_attach_task_current_cg() API is called by a thread to attach another thread to all of its cgroups; this is unsuitable for cases where a privileged task wants to attach itself to the cgroups of a less privileged one, since the call must be made from the context of the target task. This patch adds a more generic cgroup_attach_task_all() API that allows both the source task and to-be-moved task to be specified. cgroup_attach_task_current_cg() becomes a specialization of the more generic new function. [menage@google.com: rewrote changelog] [akpm@linux-foundation.org: address reviewer comments] Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Alex Williamson <alex.williamson@redhat.com> Acked-by: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Ben Blum <bblum@google.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
1 files changed, 7 insertions, 6 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 192f88c5b0f..c9483d8f614 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1791,19 +1791,20 @@ out:
- * cgroup_attach_task_current_cg - attach task 'tsk' to current task's cgroup
+ * cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from'
+ * @from: attach to all cgroups of a given task
* @tsk: the task to be attached
-int cgroup_attach_task_current_cg(struct task_struct *tsk)
+int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
struct cgroupfs_root *root;
- struct cgroup *cur_cg;
int retval = 0;
for_each_active_root(root) {
- cur_cg = task_cgroup_from_root(current, root);
- retval = cgroup_attach_task(cur_cg, tsk);
+ struct cgroup *from_cg = task_cgroup_from_root(from, root);
+ retval = cgroup_attach_task(from_cg, tsk);
if (retval)
@@ -1811,7 +1812,7 @@ int cgroup_attach_task_current_cg(struct task_struct *tsk)
return retval;
* Attach task with pid 'pid' to cgroup 'cgrp'. Call with cgroup_mutex