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Merge branch 'cgroup/for-3.14-fixes' into cgroup/for-3.15 

Pull for-3.14-fixes to receive 0ab02ca8f8 ("cgroup: protect
modifications to cgroup_idr with cgroup_mutex") prior to kernfs
conversion series to avoid non-trivial conflicts.

Signed-off-by: Tejun Heo <tj@kernel.org>
hifive-unleashed-5.1
Tejun Heo 2014-02-11 11:02:59 -05:00
parent f7cef064aa 0ab02ca8f8
commit 398f878789
2 changed files with 20 additions and 16 deletions
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2
include/linux/cgroup.h
View File

@ -151,6 +151,8 @@ struct cgroup {
*
* The ID of the root cgroup is always 0, and a new cgroup
* will be assigned with a smallest available ID.
*
* Allocating/Removing ID must be protected by cgroup_mutex.
*/
int id;

34
kernel/cgroup.c
View File

@ -850,7 +850,9 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode)
* per-subsystem and moved to css->id so that lookups are
* successful until the target css is released.
*/
mutex_lock(&cgroup_mutex);
idr_remove(&cgrp->root->cgroup_idr, cgrp->id);
mutex_unlock(&cgroup_mutex);
cgrp->id = -1;
call_rcu(&cgrp->rcu_head, cgroup_free_rcu);
@ -4091,16 +4093,6 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
}
rcu_assign_pointer(cgrp->name, name);
/*
* Temporarily set the pointer to NULL, so idr_find() won't return
* a half-baked cgroup.
*/
cgrp->id = idr_alloc(&root->cgroup_idr, NULL, 1, 0, GFP_KERNEL);
if (cgrp->id < 0) {
err = -ENOMEM;
goto err_free_name;
}
/*
* Only live parents can have children. Note that the liveliness
* check isn't strictly necessary because cgroup_mkdir() and
@ -4110,7 +4102,17 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
*/
if (!cgroup_lock_live_group(parent)) {
err = -ENODEV;
goto err_free_id;
goto err_free_name;
}
/*
* Temporarily set the pointer to NULL, so idr_find() won't return
* a half-baked cgroup.
*/
cgrp->id = idr_alloc(&root->cgroup_idr, NULL, 1, 0, GFP_KERNEL);
if (cgrp->id < 0) {
err = -ENOMEM;
goto err_unlock;
}
/* Grab a reference on the superblock so the hierarchy doesn't
@ -4142,7 +4144,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
*/
err = cgroup_create_file(dentry, S_IFDIR | mode, sb);
if (err < 0)
goto err_unlock;
goto err_free_id;
lockdep_assert_held(&dentry->d_inode->i_mutex);
cgrp->serial_nr = cgroup_serial_nr_next++;
@ -4178,12 +4180,12 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
return 0;
err_unlock:
mutex_unlock(&cgroup_mutex);
/* Release the reference count that we took on the superblock */
deactivate_super(sb);
err_free_id:
idr_remove(&root->cgroup_idr, cgrp->id);
/* Release the reference count that we took on the superblock */
deactivate_super(sb);
err_unlock:
mutex_unlock(&cgroup_mutex);
err_free_name:
kfree(rcu_dereference_raw(cgrp->name));
err_free_cgrp: