diff options
| -rw-r--r-- | kernel/cgroup/cgroup.c | 140 |
1 files changed, 79 insertions, 61 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index d34c170f87ef..228dd9ae708b 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1989,48 +1989,55 @@ out: return ret; } -static struct dentry *cgroup_mount(struct file_system_type *fs_type, - int flags, const char *unused_dev_name, - void *data) +static struct dentry *cgroup_do_mount(struct file_system_type *fs_type, + int flags, struct cgroup_root *root, + unsigned long magic, + struct cgroup_namespace *ns) { - bool is_v2 = fs_type == &cgroup2_fs_type; - struct super_block *pinned_sb = NULL; - struct cgroup_namespace *ns = current->nsproxy->cgroup_ns; - struct cgroup_subsys *ss; - struct cgroup_root *root; - struct cgroup_sb_opts opts; struct dentry *dentry; - int ret; - int i; bool new_sb; - get_cgroup_ns(ns); - - /* Check if the caller has permission to mount. */ - if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) { - put_cgroup_ns(ns); - return ERR_PTR(-EPERM); - } + dentry = kernfs_mount(fs_type, flags, root->kf_root, magic, &new_sb); /* - * The first time anyone tries to mount a cgroup, enable the list - * linking each css_set to its tasks and fix up all existing tasks. + * In non-init cgroup namespace, instead of root cgroup's dentry, + * we return the dentry corresponding to the cgroupns->root_cgrp. */ - if (!use_task_css_set_links) - cgroup_enable_task_cg_lists(); + if (!IS_ERR(dentry) && ns != &init_cgroup_ns) { + struct dentry *nsdentry; + struct cgroup *cgrp; - if (is_v2) { - if (data) { - pr_err("cgroup2: unknown option \"%s\"\n", (char *)data); - put_cgroup_ns(ns); - return ERR_PTR(-EINVAL); - } - cgrp_dfl_visible = true; - root = &cgrp_dfl_root; - cgroup_get(&root->cgrp); - goto out_mount; + mutex_lock(&cgroup_mutex); + spin_lock_irq(&css_set_lock); + + cgrp = cset_cgroup_from_root(ns->root_cset, root); + + spin_unlock_irq(&css_set_lock); + mutex_unlock(&cgroup_mutex); + + nsdentry = kernfs_node_dentry(cgrp->kn, dentry->d_sb); + dput(dentry); + dentry = nsdentry; } + if (IS_ERR(dentry) || !new_sb) + cgroup_put(&root->cgrp); + + return dentry; +} + +static struct dentry *cgroup1_mount(struct file_system_type *fs_type, + int flags, void *data, + unsigned long magic, + struct cgroup_namespace *ns) +{ + struct super_block *pinned_sb = NULL; + struct cgroup_sb_opts opts; + struct cgroup_root *root; + struct cgroup_subsys *ss; + struct dentry *dentry; + int i, ret; + cgroup_lock_and_drain_offline(&cgrp_dfl_root.cgrp); /* First find the desired set of subsystems */ @@ -2152,47 +2159,58 @@ out_free: kfree(opts.release_agent); kfree(opts.name); - if (ret) { - put_cgroup_ns(ns); + if (ret) return ERR_PTR(ret); - } -out_mount: - dentry = kernfs_mount(fs_type, flags, root->kf_root, - is_v2 ? CGROUP2_SUPER_MAGIC : CGROUP_SUPER_MAGIC, - &new_sb); + + dentry = cgroup_do_mount(&cgroup_fs_type, flags, root, + CGROUP_SUPER_MAGIC, ns); /* - * In non-init cgroup namespace, instead of root cgroup's - * dentry, we return the dentry corresponding to the - * cgroupns->root_cgrp. + * If @pinned_sb, we're reusing an existing root and holding an + * extra ref on its sb. Mount is complete. Put the extra ref. */ - if (!IS_ERR(dentry) && ns != &init_cgroup_ns) { - struct dentry *nsdentry; - struct cgroup *cgrp; + if (pinned_sb) + deactivate_super(pinned_sb); - mutex_lock(&cgroup_mutex); - spin_lock_irq(&css_set_lock); + return dentry; +} - cgrp = cset_cgroup_from_root(ns->root_cset, root); +static struct dentry *cgroup_mount(struct file_system_type *fs_type, + int flags, const char *unused_dev_name, + void *data) +{ + struct cgroup_namespace *ns = current->nsproxy->cgroup_ns; + struct dentry *dentry; - spin_unlock_irq(&css_set_lock); - mutex_unlock(&cgroup_mutex); + get_cgroup_ns(ns); - nsdentry = kernfs_node_dentry(cgrp->kn, dentry->d_sb); - dput(dentry); - dentry = nsdentry; + /* Check if the caller has permission to mount. */ + if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) { + put_cgroup_ns(ns); + return ERR_PTR(-EPERM); } - if (IS_ERR(dentry) || !new_sb) - cgroup_put(&root->cgrp); - /* - * If @pinned_sb, we're reusing an existing root and holding an - * extra ref on its sb. Mount is complete. Put the extra ref. + * The first time anyone tries to mount a cgroup, enable the list + * linking each css_set to its tasks and fix up all existing tasks. */ - if (pinned_sb) { - WARN_ON(new_sb); - deactivate_super(pinned_sb); + if (!use_task_css_set_links) + cgroup_enable_task_cg_lists(); + + if (fs_type == &cgroup2_fs_type) { + if (data) { + pr_err("cgroup2: unknown option \"%s\"\n", (char *)data); + put_cgroup_ns(ns); + return ERR_PTR(-EINVAL); + } + cgrp_dfl_visible = true; + cgroup_get(&cgrp_dfl_root.cgrp); + + dentry = cgroup_do_mount(&cgroup2_fs_type, flags, &cgrp_dfl_root, + CGROUP2_SUPER_MAGIC, ns); + } else { + dentry = cgroup1_mount(&cgroup_fs_type, flags, data, + CGROUP_SUPER_MAGIC, ns); } put_cgroup_ns(ns); |