cgroup: update cgroup_create() failure path

cgroup_create() was ignoring failure of cgroupfs files.  Update it
such that, if file creation fails, it rolls back by calling
cgroup_destroy_locked() and returns failure.

Note that error out goto labels are renamed.  The labels are a bit
confusing but will become better w/ later cgroup operation renames.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
This commit is contained in:
Tejun Heo 2012-11-19 08:13:38 -08:00
parent b8a2df6a5b
commit 4b8b47eb00

View file

@ -4107,7 +4107,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
*/ */
if (!cgroup_lock_live_group(parent)) { if (!cgroup_lock_live_group(parent)) {
err = -ENODEV; err = -ENODEV;
goto err_free; goto err_free_cgrp;
} }
/* Grab a reference on the superblock so the hierarchy doesn't /* Grab a reference on the superblock so the hierarchy doesn't
@ -4135,13 +4135,13 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
css = ss->create(cgrp); css = ss->create(cgrp);
if (IS_ERR(css)) { if (IS_ERR(css)) {
err = PTR_ERR(css); err = PTR_ERR(css);
goto err_destroy; goto err_free_all;
} }
init_cgroup_css(css, ss, cgrp); init_cgroup_css(css, ss, cgrp);
if (ss->use_id) { if (ss->use_id) {
err = alloc_css_id(ss, parent, cgrp); err = alloc_css_id(ss, parent, cgrp);
if (err) if (err)
goto err_destroy; goto err_free_all;
} }
/* At error, ->destroy() callback has to free assigned ID. */ /* At error, ->destroy() callback has to free assigned ID. */
if (clone_children(parent) && ss->post_clone) if (clone_children(parent) && ss->post_clone)
@ -4164,7 +4164,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
*/ */
err = cgroup_create_file(dentry, S_IFDIR | mode, sb); err = cgroup_create_file(dentry, S_IFDIR | mode, sb);
if (err < 0) if (err < 0)
goto err_destroy; goto err_free_all;
lockdep_assert_held(&dentry->d_inode->i_mutex); lockdep_assert_held(&dentry->d_inode->i_mutex);
/* allocation complete, commit to creation */ /* allocation complete, commit to creation */
@ -4183,14 +4183,15 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
} }
err = cgroup_populate_dir(cgrp, true, root->subsys_mask); err = cgroup_populate_dir(cgrp, true, root->subsys_mask);
/* If err < 0, we have a half-filled directory - oh well ;) */ if (err)
goto err_destroy;
mutex_unlock(&cgroup_mutex); mutex_unlock(&cgroup_mutex);
mutex_unlock(&cgrp->dentry->d_inode->i_mutex); mutex_unlock(&cgrp->dentry->d_inode->i_mutex);
return 0; return 0;
err_destroy: err_free_all:
for_each_subsys(root, ss) { for_each_subsys(root, ss) {
if (cgrp->subsys[ss->subsys_id]) if (cgrp->subsys[ss->subsys_id])
ss->destroy(cgrp); ss->destroy(cgrp);
@ -4198,9 +4199,15 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
mutex_unlock(&cgroup_mutex); mutex_unlock(&cgroup_mutex);
/* Release the reference count that we took on the superblock */ /* Release the reference count that we took on the superblock */
deactivate_super(sb); deactivate_super(sb);
err_free: err_free_cgrp:
kfree(cgrp); kfree(cgrp);
return err; return err;
err_destroy:
cgroup_destroy_locked(cgrp);
mutex_unlock(&cgroup_mutex);
mutex_unlock(&dentry->d_inode->i_mutex);
return err;
} }
static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)