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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-10-22 07:20:34 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-10-22 07:20:34 (GMT) |
commit | ee7eafc907db64ef4cbe8a17da3a1089cbe50617 (patch) | |
tree | 448cfbb1827083f875729135d4ab0d00b0f0752b | |
parent | 0df651a0740c9663093265277c32f0806e8ac23e (diff) | |
parent | ea84753c98a7ac6b74e530b64c444a912b3835ca (diff) | |
download | linux-ee7eafc907db64ef4cbe8a17da3a1089cbe50617.tar.xz |
Merge branch 'for-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
"Two late fixes for cgroup.
One fixes descendant walk introduced during this rc1 cycle. The other
fixes a post 3.9 bug during task attach which can lead to hang. Both
fixes are critical and the fixes are relatively straight-forward"
* 'for-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix to break the while loop in cgroup_attach_task() correctly
cgroup: fix cgroup post-order descendant walk of empty subtree
-rw-r--r-- | kernel/cgroup.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 2418b6e..8bd9cfd 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -2039,7 +2039,7 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, /* @tsk either already exited or can't exit until the end */ if (tsk->flags & PF_EXITING) - continue; + goto next; /* as per above, nr_threads may decrease, but not increase. */ BUG_ON(i >= group_size); @@ -2047,7 +2047,7 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, ent.cgrp = task_cgroup_from_root(tsk, root); /* nothing to do if this task is already in the cgroup */ if (ent.cgrp == cgrp) - continue; + goto next; /* * saying GFP_ATOMIC has no effect here because we did prealloc * earlier, but it's good form to communicate our expectations. @@ -2055,7 +2055,7 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, retval = flex_array_put(group, i, &ent, GFP_ATOMIC); BUG_ON(retval != 0); i++; - + next: if (!threadgroup) break; } while_each_thread(leader, tsk); @@ -3188,11 +3188,9 @@ css_next_descendant_post(struct cgroup_subsys_state *pos, WARN_ON_ONCE(!rcu_read_lock_held()); - /* if first iteration, visit the leftmost descendant */ - if (!pos) { - next = css_leftmost_descendant(root); - return next != root ? next : NULL; - } + /* if first iteration, visit leftmost descendant which may be @root */ + if (!pos) + return css_leftmost_descendant(root); /* if we visited @root, we're done */ if (pos == root) |