Re: [PATCH 1/3] cgroup: fix locking in cgroupstats_build()
On Fri, Feb 14, 2014 at 04:54:28PM +0800, Li Zefan wrote: > css_set_lock has been converted to css_set_rwsem, and rwsem can't > nested inside rcu_read_lock. > > Signed-off-by: Li Zefan Applied 1-3 to cgroup/for-3.15. Thanks! -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 1/3] cgroup: fix locking in cgroupstats_build()
css_set_lock has been converted to css_set_rwsem, and rwsem can't
nested inside rcu_read_lock.
Signed-off-by: Li Zefan
---
kernel/cgroup.c | 8 ++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index af4ecc3..0e794ca 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2997,6 +2997,8 @@ int cgroupstats_build(struct cgroupstats *stats, struct
dentry *dentry)
kernfs_type(kn) != KERNFS_DIR)
return -EINVAL;
+ mutex_lock(_mutex);
+
/*
* We aren't being called from kernfs and there's no guarantee on
* @kn->priv's validity. For this and css_tryget_from_dir(),
@@ -3004,10 +3006,12 @@ int cgroupstats_build(struct cgroupstats *stats, struct
dentry *dentry)
*/
rcu_read_lock();
cgrp = rcu_dereference(kn->priv);
- if (!cgrp) {
+ if (!cgrp || cgroup_is_dead(cgrp)) {
rcu_read_unlock();
+ mutex_unlock(_mutex);
return -ENOENT;
}
+ rcu_read_unlock();
css_task_iter_start(>dummy_css, );
while ((tsk = css_task_iter_next())) {
@@ -3032,7 +3036,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct
dentry *dentry)
}
css_task_iter_end();
- rcu_read_unlock();
+ mutex_unlock(_mutex);
return 0;
}
--
1.8.0.2
--
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[PATCH 1/3] cgroup: fix locking in cgroupstats_build()
css_set_lock has been converted to css_set_rwsem, and rwsem can't
nested inside rcu_read_lock.
Signed-off-by: Li Zefan lize...@huawei.com
---
kernel/cgroup.c | 8 ++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index af4ecc3..0e794ca 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2997,6 +2997,8 @@ int cgroupstats_build(struct cgroupstats *stats, struct
dentry *dentry)
kernfs_type(kn) != KERNFS_DIR)
return -EINVAL;
+ mutex_lock(cgroup_mutex);
+
/*
* We aren't being called from kernfs and there's no guarantee on
* @kn-priv's validity. For this and css_tryget_from_dir(),
@@ -3004,10 +3006,12 @@ int cgroupstats_build(struct cgroupstats *stats, struct
dentry *dentry)
*/
rcu_read_lock();
cgrp = rcu_dereference(kn-priv);
- if (!cgrp) {
+ if (!cgrp || cgroup_is_dead(cgrp)) {
rcu_read_unlock();
+ mutex_unlock(cgroup_mutex);
return -ENOENT;
}
+ rcu_read_unlock();
css_task_iter_start(cgrp-dummy_css, it);
while ((tsk = css_task_iter_next(it))) {
@@ -3032,7 +3036,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct
dentry *dentry)
}
css_task_iter_end(it);
- rcu_read_unlock();
+ mutex_unlock(cgroup_mutex);
return 0;
}
--
1.8.0.2
--
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the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 1/3] cgroup: fix locking in cgroupstats_build()
On Fri, Feb 14, 2014 at 04:54:28PM +0800, Li Zefan wrote: css_set_lock has been converted to css_set_rwsem, and rwsem can't nested inside rcu_read_lock. Signed-off-by: Li Zefan lize...@huawei.com Applied 1-3 to cgroup/for-3.15. Thanks! -- tejun -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
