diff options
| -rw-r--r-- | kernel/cgroup.c | 232 |
1 files changed, 117 insertions, 115 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 9e9e8fd632d8..d8efca44de5f 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -170,6 +170,8 @@ static int need_forkexit_callback __read_mostly; static struct cftype cgroup_base_files[]; static void cgroup_put(struct cgroup *cgrp); +static int rebind_subsystems(struct cgroupfs_root *root, + unsigned long added_mask, unsigned removed_mask); static void cgroup_destroy_css_killed(struct cgroup *cgrp); static int cgroup_destroy_locked(struct cgroup *cgrp); static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[], @@ -690,6 +692,42 @@ static struct css_set *find_css_set(struct css_set *old_cset, return cset; } +static int cgroup_init_root_id(struct cgroupfs_root *root, int start, int end) +{ + int id; + + lockdep_assert_held(&cgroup_mutex); + + id = idr_alloc_cyclic(&cgroup_hierarchy_idr, root, start, end, + GFP_KERNEL); + if (id < 0) + return id; + + root->hierarchy_id = id; + return 0; +} + +static void cgroup_exit_root_id(struct cgroupfs_root *root) +{ + lockdep_assert_held(&cgroup_mutex); + + if (root->hierarchy_id) { + idr_remove(&cgroup_hierarchy_idr, root->hierarchy_id); + root->hierarchy_id = 0; + } +} + +static void cgroup_free_root(struct cgroupfs_root *root) +{ + if (root) { + /* hierarhcy ID shoulid already have been released */ + WARN_ON_ONCE(root->hierarchy_id); + + idr_destroy(&root->cgroup_idr); + kfree(root); + } +} + static void cgroup_get_root(struct cgroupfs_root *root) { atomic_inc(&root->sb->s_active); @@ -700,6 +738,59 @@ static void cgroup_put_root(struct cgroupfs_root *root) deactivate_super(root->sb); } +static void cgroup_kill_sb(struct super_block *sb) +{ + struct cgroupfs_root *root = sb->s_fs_info; + struct cgroup *cgrp = &root->top_cgroup; + struct cgrp_cset_link *link, *tmp_link; + int ret; + + BUG_ON(!root); + + BUG_ON(root->number_of_cgroups != 1); + BUG_ON(!list_empty(&cgrp->children)); + + mutex_lock(&cgrp->dentry->d_inode->i_mutex); + mutex_lock(&cgroup_tree_mutex); + mutex_lock(&cgroup_mutex); + + /* Rebind all subsystems back to the default hierarchy */ + if (root->flags & CGRP_ROOT_SUBSYS_BOUND) { + ret = rebind_subsystems(root, 0, root->subsys_mask); + /* Shouldn't be able to fail ... */ + BUG_ON(ret); + } + + /* + * Release all the links from cset_links to this hierarchy's + * root cgroup + */ + write_lock(&css_set_lock); + + list_for_each_entry_safe(link, tmp_link, &cgrp->cset_links, cset_link) { + list_del(&link->cset_link); + list_del(&link->cgrp_link); + kfree(link); + } + write_unlock(&css_set_lock); + + if (!list_empty(&root->root_list)) { + list_del(&root->root_list); + cgroup_root_count--; + } + + cgroup_exit_root_id(root); + + mutex_unlock(&cgroup_mutex); + mutex_unlock(&cgroup_tree_mutex); + mutex_unlock(&cgrp->dentry->d_inode->i_mutex); + + simple_xattrs_free(&cgrp->xattrs); + + kill_litter_super(sb); + cgroup_free_root(root); +} + /* * Return the cgroup for "task" from the given hierarchy. Must be * called with cgroup_mutex held. @@ -846,6 +937,32 @@ static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft, return buf; } +/** + * cgroup_file_mode - deduce file mode of a control file + * @cft: the control file in question + * + * returns cft->mode if ->mode is not 0 + * returns S_IRUGO|S_IWUSR if it has both a read and a write handler + * returns S_IRUGO if it has only a read handler + * returns S_IWUSR if it has only a write hander + */ +static umode_t cgroup_file_mode(const struct cftype *cft) +{ + umode_t mode = 0; + + if (cft->mode) + return cft->mode; + + if (cft->read_u64 || cft->read_s64 || cft->seq_show) + mode |= S_IRUGO; + + if (cft->write_u64 || cft->write_s64 || cft->write_string || + cft->trigger) + mode |= S_IWUSR; + + return mode; +} + static void cgroup_free_fn(struct work_struct *work) { struct cgroup *cgrp = container_of(work, struct cgroup, destroy_work); @@ -1358,31 +1475,6 @@ static void init_cgroup_root(struct cgroupfs_root *root) idr_init(&root->cgroup_idr); } -static int cgroup_init_root_id(struct cgroupfs_root *root, int start, int end) -{ - int id; - - lockdep_assert_held(&cgroup_mutex); - - id = idr_alloc_cyclic(&cgroup_hierarchy_idr, root, start, end, - GFP_KERNEL); - if (id < 0) - return id; - - root->hierarchy_id = id; - return 0; -} - -static void cgroup_exit_root_id(struct cgroupfs_root *root) -{ - lockdep_assert_held(&cgroup_mutex); - - if (root->hierarchy_id) { - idr_remove(&cgroup_hierarchy_idr, root->hierarchy_id); - root->hierarchy_id = 0; - } -} - static int cgroup_test_super(struct super_block *sb, void *data) { struct cgroup_sb_opts *opts = data; @@ -1435,17 +1527,6 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts) return root; } -static void cgroup_free_root(struct cgroupfs_root *root) -{ - if (root) { - /* hierarhcy ID shoulid already have been released */ - WARN_ON_ONCE(root->hierarchy_id); - - idr_destroy(&root->cgroup_idr); - kfree(root); - } -} - static int cgroup_set_super(struct super_block *sb, void *data) { int ret; @@ -1691,59 +1772,6 @@ out_unlock: return ERR_PTR(ret); } -static void cgroup_kill_sb(struct super_block *sb) -{ - struct cgroupfs_root *root = sb->s_fs_info; - struct cgroup *cgrp = &root->top_cgroup; - struct cgrp_cset_link *link, *tmp_link; - int ret; - - BUG_ON(!root); - - BUG_ON(root->number_of_cgroups != 1); - BUG_ON(!list_empty(&cgrp->children)); - - mutex_lock(&cgrp->dentry->d_inode->i_mutex); - mutex_lock(&cgroup_tree_mutex); - mutex_lock(&cgroup_mutex); - - /* Rebind all subsystems back to the default hierarchy */ - if (root->flags & CGRP_ROOT_SUBSYS_BOUND) { - ret = rebind_subsystems(root, 0, root->subsys_mask); - /* Shouldn't be able to fail ... */ - BUG_ON(ret); - } - - /* - * Release all the links from cset_links to this hierarchy's - * root cgroup - */ - write_lock(&css_set_lock); - - list_for_each_entry_safe(link, tmp_link, &cgrp->cset_links, cset_link) { - list_del(&link->cset_link); - list_del(&link->cgrp_link); - kfree(link); - } - write_unlock(&css_set_lock); - - if (!list_empty(&root->root_list)) { - list_del(&root->root_list); - cgroup_root_count--; - } - - cgroup_exit_root_id(root); - - mutex_unlock(&cgroup_mutex); - mutex_unlock(&cgroup_tree_mutex); - mutex_unlock(&cgrp->dentry->d_inode->i_mutex); - - simple_xattrs_free(&cgrp->xattrs); - - kill_litter_super(sb); - cgroup_free_root(root); -} - static struct file_system_type cgroup_fs_type = { .name = "cgroup", .mount = cgroup_mount, @@ -2619,32 +2647,6 @@ static int cgroup_create_file(struct dentry *dentry, umode_t mode, return 0; } -/** - * cgroup_file_mode - deduce file mode of a control file - * @cft: the control file in question - * - * returns cft->mode if ->mode is not 0 - * returns S_IRUGO|S_IWUSR if it has both a read and a write handler - * returns S_IRUGO if it has only a read handler - * returns S_IWUSR if it has only a write hander - */ -static umode_t cgroup_file_mode(const struct cftype *cft) -{ - umode_t mode = 0; - - if (cft->mode) - return cft->mode; - - if (cft->read_u64 || cft->read_s64 || cft->seq_show) - mode |= S_IRUGO; - - if (cft->write_u64 || cft->write_s64 || cft->write_string || - cft->trigger) - mode |= S_IWUSR; - - return mode; -} - static int cgroup_add_file(struct cgroup *cgrp, struct cftype *cft) { struct dentry *dir = cgrp->dentry; |