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| author | Zefan Li <lizefan@huawei.com> | 2017-04-19 10:15:59 +0800 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2017-04-28 18:04:54 -0400 |
| commit | 9732adc5d6520238223df16630f1f8cad2269317 (patch) | |
| tree | b10b3242df285c38a45e4b8039b2e860a9e20def /kernel/cgroup/cgroup.c | |
| parent | a590b90d472f2c176c140576ee3ab44df7f67839 (diff) | |
| download | lwn-9732adc5d6520238223df16630f1f8cad2269317.tar.gz lwn-9732adc5d6520238223df16630f1f8cad2269317.zip | |
cgroup: avoid attaching a cgroup root to two different superblocks, take 2
Commit bfb0b80db5f9 ("cgroup: avoid attaching a cgroup root to two
different superblocks") is broken. Now we try to fix the race by
delaying the initialization of cgroup root refcnt until a superblock
has been allocated.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Tested-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup/cgroup.c')
| -rw-r--r-- | kernel/cgroup/cgroup.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 10951d5e35d2..38d9386f46e7 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1645,7 +1645,7 @@ void init_cgroup_root(struct cgroup_root *root, struct cgroup_sb_opts *opts) set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags); } -int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) +int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask, int ref_flags) { LIST_HEAD(tmp_links); struct cgroup *root_cgrp = &root->cgrp; @@ -1661,8 +1661,8 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) root_cgrp->id = ret; root_cgrp->ancestor_ids[0] = ret; - ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release, 0, - GFP_KERNEL); + ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release, + ref_flags, GFP_KERNEL); if (ret) goto out; @@ -4517,7 +4517,7 @@ int __init cgroup_init(void) hash_add(css_set_table, &init_css_set.hlist, css_set_hash(init_css_set.subsys)); - BUG_ON(cgroup_setup_root(&cgrp_dfl_root, 0)); + BUG_ON(cgroup_setup_root(&cgrp_dfl_root, 0, 0)); mutex_unlock(&cgroup_mutex); |