X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=kernel%2Fcgroup.c;h=3f65933335253d8be3e4dfd2b59839018f8ee3ad;hb=4e96ee8e981b5140a2bcc5fff0d5c0eef39a62ee;hp=e5583d10a325657620add60075ae0c9eead92617;hpb=746919d2668037f297595da9281a22cd558f3d18;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git diff --git a/kernel/cgroup.c b/kernel/cgroup.c index e5583d1..3f65933 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -215,6 +215,8 @@ static u64 cgroup_serial_nr_next = 1; */ static int need_forkexit_callback __read_mostly; +static struct cftype cgroup_base_files[]; + static void cgroup_offline_fn(struct work_struct *work); static int cgroup_destroy_locked(struct cgroup *cgrp); static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys, @@ -464,7 +466,7 @@ static inline void put_css_set_taskexit(struct css_set *cset) * @new_cgrp: cgroup that's being entered by the task * @template: desired set of css pointers in css_set (pre-calculated) * - * Returns true if "cg" matches "old_cg" except for the hierarchy + * Returns true if "cset" matches "old_cset" except for the hierarchy * which "new_cgrp" belongs to, for which it should match "new_cgrp". */ static bool compare_css_sets(struct css_set *cset, @@ -804,8 +806,7 @@ static struct cgroup *task_cgroup_from_root(struct task_struct *task, static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode); static struct dentry *cgroup_lookup(struct inode *, struct dentry *, unsigned int); static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry); -static int cgroup_populate_dir(struct cgroup *cgrp, bool base_files, - unsigned long subsys_mask); +static int cgroup_populate_dir(struct cgroup *cgrp, unsigned long subsys_mask); static const struct inode_operations cgroup_dir_inode_operations; static const struct file_operations proc_cgroupstats_operations; @@ -865,8 +866,6 @@ static void cgroup_free_fn(struct work_struct *work) */ dput(cgrp->parent->dentry); - ida_simple_remove(&cgrp->root->cgroup_ida, cgrp->id); - /* * Drop the active superblock reference that we took when we * created the cgroup. This will free cgrp->root, if we are @@ -957,28 +956,23 @@ static void cgroup_rm_file(struct cgroup *cgrp, const struct cftype *cft) } /** - * cgroup_clear_directory - selective removal of base and subsystem files - * @dir: directory containing the files - * @base_files: true if the base files should be removed + * cgroup_clear_dir - remove subsys files in a cgroup directory + * @cgrp: target cgroup * @subsys_mask: mask of the subsystem ids whose files should be removed */ -static void cgroup_clear_directory(struct dentry *dir, bool base_files, - unsigned long subsys_mask) +static void cgroup_clear_dir(struct cgroup *cgrp, unsigned long subsys_mask) { - struct cgroup *cgrp = __d_cgrp(dir); struct cgroup_subsys *ss; + int i; - for_each_root_subsys(cgrp->root, ss) { + for_each_subsys(ss, i) { struct cftype_set *set; - if (!test_bit(ss->subsys_id, &subsys_mask)) + + if (!test_bit(i, &subsys_mask)) continue; list_for_each_entry(set, &ss->cftsets, node) cgroup_addrm_files(cgrp, NULL, set->cfts, false); } - if (base_files) { - while (!list_empty(&cgrp->files)) - cgroup_rm_file(cgrp, NULL); - } } /* @@ -987,9 +981,6 @@ static void cgroup_clear_directory(struct dentry *dir, bool base_files, static void cgroup_d_remove_dir(struct dentry *dentry) { struct dentry *parent; - struct cgroupfs_root *root = dentry->d_sb->s_fs_info; - - cgroup_clear_directory(dentry, true, root->subsys_mask); parent = dentry->d_parent; spin_lock(&parent->d_lock); @@ -1010,32 +1001,47 @@ static int rebind_subsystems(struct cgroupfs_root *root, { struct cgroup *cgrp = &root->top_cgroup; struct cgroup_subsys *ss; - int i; + unsigned long pinned = 0; + int i, ret; BUG_ON(!mutex_is_locked(&cgroup_mutex)); BUG_ON(!mutex_is_locked(&cgroup_root_mutex)); /* Check that any added subsystems are currently free */ for_each_subsys(ss, i) { - unsigned long bit = 1UL << i; - - if (!(bit & added_mask)) + if (!(added_mask & (1 << i))) continue; + /* is the subsystem mounted elsewhere? */ if (ss->root != &cgroup_dummy_root) { - /* Subsystem isn't free */ - return -EBUSY; + ret = -EBUSY; + goto out_put; + } + + /* pin the module */ + if (!try_module_get(ss->module)) { + ret = -ENOENT; + goto out_put; } + pinned |= 1 << i; } - /* Currently we don't handle adding/removing subsystems when - * any child cgroups exist. This is theoretically supportable - * but involves complex error handling, so it's being left until - * later */ - if (root->number_of_cgroups > 1) - return -EBUSY; + /* subsys could be missing if unloaded between parsing and here */ + if (added_mask != pinned) { + ret = -ENOENT; + goto out_put; + } + + ret = cgroup_populate_dir(cgrp, added_mask); + if (ret) + goto out_put; + + /* + * Nothing can fail from this point on. Remove files for the + * removed subsystems and rebind each subsystem. + */ + cgroup_clear_dir(cgrp, removed_mask); - /* Process each subsystem */ for_each_subsys(ss, i) { unsigned long bit = 1UL << i; @@ -1069,20 +1075,6 @@ static int rebind_subsystems(struct cgroupfs_root *root, /* subsystem is now free - drop reference on module */ module_put(ss->module); root->subsys_mask &= ~bit; - } else if (bit & root->subsys_mask) { - /* Subsystem state should already exist */ - BUG_ON(!cgrp->subsys[i]); - /* - * a refcount was taken, but we already had one, so - * drop the extra reference. - */ - module_put(ss->module); -#ifdef CONFIG_MODULE_UNLOAD - BUG_ON(ss->module && !module_refcount(ss->module)); -#endif - } else { - /* Subsystem state shouldn't exist */ - BUG_ON(cgrp->subsys[i]); } } @@ -1093,6 +1085,12 @@ static int rebind_subsystems(struct cgroupfs_root *root, root->flags |= CGRP_ROOT_SUBSYS_BOUND; return 0; + +out_put: + for_each_subsys(ss, i) + if (pinned & (1 << i)) + module_put(ss->module); + return ret; } static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry) @@ -1143,7 +1141,6 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) char *token, *o = data; bool all_ss = false, one_ss = false; unsigned long mask = (unsigned long)-1; - bool module_pin_failed = false; struct cgroup_subsys *ss; int i; @@ -1286,52 +1283,9 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts) if (!opts->subsys_mask && !opts->name) return -EINVAL; - /* - * Grab references on all the modules we'll need, so the subsystems - * don't dance around before rebind_subsystems attaches them. This may - * take duplicate reference counts on a subsystem that's already used, - * but rebind_subsystems handles this case. - */ - for_each_subsys(ss, i) { - if (!(opts->subsys_mask & (1UL << i))) - continue; - if (!try_module_get(cgroup_subsys[i]->module)) { - module_pin_failed = true; - break; - } - } - if (module_pin_failed) { - /* - * oops, one of the modules was going away. this means that we - * raced with a module_delete call, and to the user this is - * essentially a "subsystem doesn't exist" case. - */ - for (i--; i >= 0; i--) { - /* drop refcounts only on the ones we took */ - unsigned long bit = 1UL << i; - - if (!(bit & opts->subsys_mask)) - continue; - module_put(cgroup_subsys[i]->module); - } - return -ENOENT; - } - return 0; } -static void drop_parsed_module_refcounts(unsigned long subsys_mask) -{ - struct cgroup_subsys *ss; - int i; - - mutex_lock(&cgroup_mutex); - for_each_subsys(ss, i) - if (subsys_mask & (1UL << i)) - module_put(cgroup_subsys[i]->module); - mutex_unlock(&cgroup_mutex); -} - static int cgroup_remount(struct super_block *sb, int *flags, char *data) { int ret = 0; @@ -1371,22 +1325,15 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) goto out_unlock; } - /* - * Clear out the files of subsystems that should be removed, do - * this before rebind_subsystems, since rebind_subsystems may - * change this hierarchy's subsys_list. - */ - cgroup_clear_directory(cgrp->dentry, false, removed_mask); - - ret = rebind_subsystems(root, added_mask, removed_mask); - if (ret) { - /* rebind_subsystems failed, re-populate the removed files */ - cgroup_populate_dir(cgrp, false, removed_mask); + /* remounting is not allowed for populated hierarchies */ + if (root->number_of_cgroups > 1) { + ret = -EBUSY; goto out_unlock; } - /* re-populate subsystem files */ - cgroup_populate_dir(cgrp, false, added_mask); + ret = rebind_subsystems(root, added_mask, removed_mask); + if (ret) + goto out_unlock; if (opts.release_agent) strcpy(root->release_agent_path, opts.release_agent); @@ -1396,8 +1343,6 @@ static int cgroup_remount(struct super_block *sb, int *flags, char *data) mutex_unlock(&cgroup_root_mutex); mutex_unlock(&cgroup_mutex); mutex_unlock(&cgrp->dentry->d_inode->i_mutex); - if (ret) - drop_parsed_module_refcounts(opts.subsys_mask); return ret; } @@ -1432,6 +1377,7 @@ static void init_cgroup_root(struct cgroupfs_root *root) cgrp->root = root; RCU_INIT_POINTER(cgrp->name, &root_cgroup_name); init_cgroup_housekeeping(cgrp); + idr_init(&root->cgroup_idr); } static int cgroup_init_root_id(struct cgroupfs_root *root, int start, int end) @@ -1504,7 +1450,6 @@ static struct cgroupfs_root *cgroup_root_from_opts(struct cgroup_sb_opts *opts) */ root->subsys_mask = opts->subsys_mask; root->flags = opts->flags; - ida_init(&root->cgroup_ida); if (opts->release_agent) strcpy(root->release_agent_path, opts->release_agent); if (opts->name) @@ -1520,7 +1465,7 @@ static void cgroup_free_root(struct cgroupfs_root *root) /* hierarhcy ID shoulid already have been released */ WARN_ON_ONCE(root->hierarchy_id); - ida_destroy(&root->cgroup_ida); + idr_destroy(&root->cgroup_idr); kfree(root); } } @@ -1585,7 +1530,9 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, int ret = 0; struct super_block *sb; struct cgroupfs_root *new_root; + struct list_head tmp_links; struct inode *inode; + const struct cred *cred; /* First find the desired set of subsystems */ mutex_lock(&cgroup_mutex); @@ -1601,7 +1548,7 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, new_root = cgroup_root_from_opts(&opts); if (IS_ERR(new_root)) { ret = PTR_ERR(new_root); - goto drop_modules; + goto out_err; } opts.new_root = new_root; @@ -1610,17 +1557,15 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, if (IS_ERR(sb)) { ret = PTR_ERR(sb); cgroup_free_root(opts.new_root); - goto drop_modules; + goto out_err; } root = sb->s_fs_info; BUG_ON(!root); if (root == opts.new_root) { /* We used the new root structure, so this is a new hierarchy */ - struct list_head tmp_links; struct cgroup *root_cgrp = &root->top_cgroup; struct cgroupfs_root *existing_root; - const struct cred *cred; int i; struct css_set *cset; @@ -1635,6 +1580,11 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, mutex_lock(&cgroup_mutex); mutex_lock(&cgroup_root_mutex); + root_cgrp->id = idr_alloc(&root->cgroup_idr, root_cgrp, + 0, 1, GFP_KERNEL); + if (root_cgrp->id < 0) + goto unlock_drop; + /* Check for name clashes with existing mounts */ ret = -EBUSY; if (strlen(root->name)) @@ -1658,26 +1608,37 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, if (ret) goto unlock_drop; + sb->s_root->d_fsdata = root_cgrp; + root_cgrp->dentry = sb->s_root; + + /* + * We're inside get_sb() and will call lookup_one_len() to + * create the root files, which doesn't work if SELinux is + * in use. The following cred dancing somehow works around + * it. See 2ce9738ba ("cgroupfs: use init_cred when + * populating new cgroupfs mount") for more details. + */ + cred = override_creds(&init_cred); + + ret = cgroup_addrm_files(root_cgrp, NULL, cgroup_base_files, true); + if (ret) + goto rm_base_files; + ret = rebind_subsystems(root, root->subsys_mask, 0); - if (ret == -EBUSY) { - free_cgrp_cset_links(&tmp_links); - goto unlock_drop; - } + if (ret) + goto rm_base_files; + + revert_creds(cred); + /* * There must be no failure case after here, since rebinding * takes care of subsystems' refcounts, which are explicitly * dropped in the failure exit path. */ - /* EBUSY should be the only error here */ - BUG_ON(ret); - list_add(&root->root_list, &cgroup_roots); cgroup_root_count++; - sb->s_root->d_fsdata = root_cgrp; - root->top_cgroup.dentry = sb->s_root; - /* Link the top cgroup in this hierarchy into all * the css_set objects */ write_lock(&css_set_lock); @@ -1690,9 +1651,6 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, BUG_ON(!list_empty(&root_cgrp->children)); BUG_ON(root->number_of_cgroups != 1); - cred = override_creds(&init_cred); - cgroup_populate_dir(root_cgrp, true, root->subsys_mask); - revert_creds(cred); mutex_unlock(&cgroup_root_mutex); mutex_unlock(&cgroup_mutex); mutex_unlock(&inode->i_mutex); @@ -1712,15 +1670,16 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, pr_warning("cgroup: new mount options do not match the existing superblock, will be ignored\n"); } } - - /* no subsys rebinding, so refcounts don't change */ - drop_parsed_module_refcounts(opts.subsys_mask); } kfree(opts.release_agent); kfree(opts.name); return dget(sb->s_root); + rm_base_files: + free_cgrp_cset_links(&tmp_links); + cgroup_addrm_files(&root->top_cgroup, NULL, cgroup_base_files, false); + revert_creds(cred); unlock_drop: cgroup_exit_root_id(root); mutex_unlock(&cgroup_root_mutex); @@ -1728,8 +1687,6 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type, mutex_unlock(&inode->i_mutex); drop_new_super: deactivate_locked_super(sb); - drop_modules: - drop_parsed_module_refcounts(opts.subsys_mask); out_err: kfree(opts.release_agent); kfree(opts.name); @@ -1747,6 +1704,7 @@ static void cgroup_kill_sb(struct super_block *sb) { BUG_ON(root->number_of_cgroups != 1); BUG_ON(!list_empty(&cgrp->children)); + mutex_lock(&cgrp->dentry->d_inode->i_mutex); mutex_lock(&cgroup_mutex); mutex_lock(&cgroup_root_mutex); @@ -1779,6 +1737,7 @@ static void cgroup_kill_sb(struct super_block *sb) { mutex_unlock(&cgroup_root_mutex); mutex_unlock(&cgroup_mutex); + mutex_unlock(&cgrp->dentry->d_inode->i_mutex); simple_xattrs_free(&cgrp->xattrs); @@ -1883,7 +1842,7 @@ EXPORT_SYMBOL_GPL(task_cgroup_path_from_hierarchy); struct task_and_cgroup { struct task_struct *task; struct cgroup *cgrp; - struct css_set *cg; + struct css_set *cset; }; struct cgroup_taskset { @@ -2101,8 +2060,8 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, tc = flex_array_get(group, i); old_cset = task_css_set(tc->task); - tc->cg = find_css_set(old_cset, cgrp); - if (!tc->cg) { + tc->cset = find_css_set(old_cset, cgrp); + if (!tc->cset) { retval = -ENOMEM; goto out_put_css_set_refs; } @@ -2115,7 +2074,7 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk, */ for (i = 0; i < group_size; i++) { tc = flex_array_get(group, i); - cgroup_task_migrate(tc->cgrp, tc->task, tc->cg); + cgroup_task_migrate(tc->cgrp, tc->task, tc->cset); } /* nothing is sensitive to fork() after this point. */ @@ -2135,9 +2094,9 @@ out_put_css_set_refs: if (retval) { for (i = 0; i < group_size; i++) { tc = flex_array_get(group, i); - if (!tc->cg) + if (!tc->cset) break; - put_css_set(tc->cg); + put_css_set(tc->cset); } } out_cancel_attach: @@ -2247,9 +2206,9 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) mutex_lock(&cgroup_mutex); for_each_active_root(root) { - struct cgroup *from_cg = task_cgroup_from_root(from, root); + struct cgroup *from_cgrp = task_cgroup_from_root(from, root); - retval = cgroup_attach_task(from_cg, tsk, false); + retval = cgroup_attach_task(from_cgrp, tsk, false); if (retval) break; } @@ -2441,11 +2400,6 @@ static ssize_t cgroup_file_read(struct file *file, char __user *buf, * supports string->u64 maps, but can be extended in future. */ -struct cgroup_seqfile_state { - struct cftype *cft; - struct cgroup *cgroup; -}; - static int cgroup_map_add(struct cgroup_map_cb *cb, const char *key, u64 value) { struct seq_file *sf = cb->state; @@ -2454,59 +2408,45 @@ static int cgroup_map_add(struct cgroup_map_cb *cb, const char *key, u64 value) static int cgroup_seqfile_show(struct seq_file *m, void *arg) { - struct cgroup_seqfile_state *state = m->private; - struct cftype *cft = state->cft; + struct cfent *cfe = m->private; + struct cftype *cft = cfe->type; + struct cgroup *cgrp = __d_cgrp(cfe->dentry->d_parent); + if (cft->read_map) { struct cgroup_map_cb cb = { .fill = cgroup_map_add, .state = m, }; - return cft->read_map(state->cgroup, cft, &cb); + return cft->read_map(cgrp, cft, &cb); } - return cft->read_seq_string(state->cgroup, cft, m); -} - -static int cgroup_seqfile_release(struct inode *inode, struct file *file) -{ - struct seq_file *seq = file->private_data; - kfree(seq->private); - return single_release(inode, file); + return cft->read_seq_string(cgrp, cft, m); } static const struct file_operations cgroup_seqfile_operations = { .read = seq_read, .write = cgroup_file_write, .llseek = seq_lseek, - .release = cgroup_seqfile_release, + .release = single_release, }; static int cgroup_file_open(struct inode *inode, struct file *file) { int err; + struct cfent *cfe; struct cftype *cft; err = generic_file_open(inode, file); if (err) return err; - cft = __d_cft(file->f_dentry); + cfe = __d_cfe(file->f_dentry); + cft = cfe->type; if (cft->read_map || cft->read_seq_string) { - struct cgroup_seqfile_state *state; - - state = kzalloc(sizeof(*state), GFP_USER); - if (!state) - return -ENOMEM; - - state->cft = cft; - state->cgroup = __d_cgrp(file->f_dentry->d_parent); file->f_op = &cgroup_seqfile_operations; - err = single_open(file, cgroup_seqfile_show, state); - if (err < 0) - kfree(state); - } else if (cft->open) + err = single_open(file, cgroup_seqfile_show, cfe); + } else if (cft->open) { err = cft->open(inode, file); - else - err = 0; + } return err; } @@ -2784,11 +2724,26 @@ out: return error; } +/** + * cgroup_addrm_files - add or remove files to a cgroup directory + * @cgrp: the target cgroup + * @subsys: the subsystem of files to be added + * @cfts: array of cftypes to be added + * @is_add: whether to add or remove + * + * Depending on @is_add, add or remove files defined by @cfts on @cgrp. + * All @cfts should belong to @subsys. For removals, this function never + * fails. If addition fails, this function doesn't remove files already + * added. The caller is responsible for cleaning up. + */ static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys, struct cftype cfts[], bool is_add) { struct cftype *cft; - int err, ret = 0; + int ret; + + lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex); + lockdep_assert_held(&cgroup_mutex); for (cft = cfts; cft->name[0] != '\0'; cft++) { /* does cft->flags tell us to skip this file on @cgrp? */ @@ -2800,16 +2755,17 @@ static int cgroup_addrm_files(struct cgroup *cgrp, struct cgroup_subsys *subsys, continue; if (is_add) { - err = cgroup_add_file(cgrp, subsys, cft); - if (err) + ret = cgroup_add_file(cgrp, subsys, cft); + if (ret) { pr_warn("cgroup_addrm_files: failed to add %s, err=%d\n", - cft->name, err); - ret = err; + cft->name, ret); + return ret; + } } else { cgroup_rm_file(cgrp, cft); } } - return ret; + return 0; } static void cgroup_cfts_prepare(void) @@ -2824,8 +2780,8 @@ static void cgroup_cfts_prepare(void) mutex_lock(&cgroup_mutex); } -static void cgroup_cfts_commit(struct cgroup_subsys *ss, - struct cftype *cfts, bool is_add) +static int cgroup_cfts_commit(struct cgroup_subsys *ss, + struct cftype *cfts, bool is_add) __releases(&cgroup_mutex) { LIST_HEAD(pending); @@ -2834,12 +2790,13 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss, struct dentry *prev = NULL; struct inode *inode; u64 update_before; + int ret = 0; /* %NULL @cfts indicates abort and don't bother if @ss isn't attached */ if (!cfts || ss->root == &cgroup_dummy_root || !atomic_inc_not_zero(&sb->s_active)) { mutex_unlock(&cgroup_mutex); - return; + return 0; } /* @@ -2855,10 +2812,13 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss, inode = root->dentry->d_inode; mutex_lock(&inode->i_mutex); mutex_lock(&cgroup_mutex); - cgroup_addrm_files(root, ss, cfts, is_add); + ret = cgroup_addrm_files(root, ss, cfts, is_add); mutex_unlock(&cgroup_mutex); mutex_unlock(&inode->i_mutex); + if (ret) + goto out_deact; + /* add/rm files for all cgroups created before */ rcu_read_lock(); cgroup_for_each_descendant_pre(cgrp, root) { @@ -2875,15 +2835,19 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss, mutex_lock(&inode->i_mutex); mutex_lock(&cgroup_mutex); if (cgrp->serial_nr < update_before && !cgroup_is_dead(cgrp)) - cgroup_addrm_files(cgrp, ss, cfts, is_add); + ret = cgroup_addrm_files(cgrp, ss, cfts, is_add); mutex_unlock(&cgroup_mutex); mutex_unlock(&inode->i_mutex); rcu_read_lock(); + if (ret) + break; } rcu_read_unlock(); dput(prev); +out_deact: deactivate_super(sb); + return ret; } /** @@ -2903,6 +2867,7 @@ static void cgroup_cfts_commit(struct cgroup_subsys *ss, int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) { struct cftype_set *set; + int ret; set = kzalloc(sizeof(*set), GFP_KERNEL); if (!set) @@ -2911,9 +2876,10 @@ int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) cgroup_cfts_prepare(); set->cfts = cfts; list_add_tail(&set->node, &ss->cftsets); - cgroup_cfts_commit(ss, cfts, true); - - return 0; + ret = cgroup_cfts_commit(ss, cfts, true); + if (ret) + cgroup_rm_cftypes(ss, cfts); + return ret; } EXPORT_SYMBOL_GPL(cgroup_add_cftypes); @@ -3342,8 +3308,8 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) * guarantees forward progress and that we don't miss any tasks. */ heap->size = 0; - cgroup_iter_start(scan->cg, &it); - while ((p = cgroup_iter_next(scan->cg, &it))) { + cgroup_iter_start(scan->cgrp, &it); + while ((p = cgroup_iter_next(scan->cgrp, &it))) { /* * Only affect tasks that qualify per the caller's callback, * if he provided one @@ -3376,7 +3342,7 @@ int cgroup_scan_tasks(struct cgroup_scanner *scan) * the heap and wasn't inserted */ } - cgroup_iter_end(scan->cg, &it); + cgroup_iter_end(scan->cgrp, &it); if (heap->size) { for (i = 0; i < heap->size; i++) { @@ -3422,7 +3388,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) { struct cgroup_scanner scan; - scan.cg = from; + scan.cgrp = from; scan.test_task = NULL; /* select all tasks in cgroup */ scan.process_task = cgroup_transfer_one_task; scan.heap = NULL; @@ -4150,31 +4116,29 @@ static struct cftype cgroup_base_files[] = { }; /** - * cgroup_populate_dir - selectively creation of files in a directory + * cgroup_populate_dir - create subsys files in a cgroup directory * @cgrp: target cgroup - * @base_files: true if the base files should be added * @subsys_mask: mask of the subsystem ids whose files should be added + * + * On failure, no file is added. */ -static int cgroup_populate_dir(struct cgroup *cgrp, bool base_files, - unsigned long subsys_mask) +static int cgroup_populate_dir(struct cgroup *cgrp, unsigned long subsys_mask) { - int err; struct cgroup_subsys *ss; - - if (base_files) { - err = cgroup_addrm_files(cgrp, NULL, cgroup_base_files, true); - if (err < 0) - return err; - } + int i, ret = 0; /* process cftsets of each subsystem */ - for_each_root_subsys(cgrp->root, ss) { + for_each_subsys(ss, i) { struct cftype_set *set; - if (!test_bit(ss->subsys_id, &subsys_mask)) + + if (!test_bit(i, &subsys_mask)) continue; - list_for_each_entry(set, &ss->cftsets, node) - cgroup_addrm_files(cgrp, ss, set->cfts, true); + list_for_each_entry(set, &ss->cftsets, node) { + ret = cgroup_addrm_files(cgrp, ss, set->cfts, true); + if (ret < 0) + goto err; + } } /* This cgroup is ready now */ @@ -4192,6 +4156,9 @@ static int cgroup_populate_dir(struct cgroup *cgrp, bool base_files, } return 0; +err: + cgroup_clear_dir(cgrp, subsys_mask); + return ret; } static void css_dput_fn(struct work_struct *work) @@ -4231,7 +4198,7 @@ static void init_cgroup_css(struct cgroup_subsys_state *css, INIT_WORK(&css->dput_work, css_dput_fn); } -/* invoke ->post_create() on a new CSS and mark it online if successful */ +/* invoke ->css_online() on a new CSS and mark it online if successful */ static int online_css(struct cgroup_subsys *ss, struct cgroup *cgrp) { int ret = 0; @@ -4245,9 +4212,8 @@ static int online_css(struct cgroup_subsys *ss, struct cgroup *cgrp) return ret; } -/* if the CSS is online, invoke ->pre_destory() on it and mark it offline */ +/* if the CSS is online, invoke ->css_offline() on it and mark it offline */ static void offline_css(struct cgroup_subsys *ss, struct cgroup *cgrp) - __releases(&cgroup_mutex) __acquires(&cgroup_mutex) { struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id]; @@ -4290,7 +4256,11 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, goto err_free_cgrp; rcu_assign_pointer(cgrp->name, name); - cgrp->id = ida_simple_get(&root->cgroup_ida, 1, 0, GFP_KERNEL); + /* + * 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) goto err_free_name; @@ -4388,7 +4358,13 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry, } } - err = cgroup_populate_dir(cgrp, true, root->subsys_mask); + idr_replace(&root->cgroup_idr, cgrp, cgrp->id); + + err = cgroup_addrm_files(cgrp, NULL, cgroup_base_files, true); + if (err) + goto err_destroy; + + err = cgroup_populate_dir(cgrp, root->subsys_mask); if (err) goto err_destroy; @@ -4410,7 +4386,7 @@ err_free_all: /* Release the reference count that we took on the superblock */ deactivate_super(sb); err_free_id: - ida_simple_remove(&root->cgroup_ida, cgrp->id); + idr_remove(&root->cgroup_idr, cgrp->id); err_free_name: kfree(rcu_dereference_raw(cgrp->name)); err_free_cgrp: @@ -4541,9 +4517,11 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) raw_spin_unlock(&release_list_lock); /* - * Remove @cgrp directory. The removal puts the base ref but we - * aren't quite done with @cgrp yet, so hold onto it. + * Clear and remove @cgrp directory. The removal puts the base ref + * but we aren't quite done with @cgrp yet, so hold onto it. */ + cgroup_clear_dir(cgrp, cgrp->root->subsys_mask); + cgroup_addrm_files(cgrp, NULL, cgroup_base_files, false); dget(d); cgroup_d_remove_dir(d); @@ -4601,6 +4579,14 @@ static void cgroup_offline_fn(struct work_struct *work) /* delete this cgroup from parent->children */ list_del_rcu(&cgrp->sibling); + /* + * We should remove the cgroup object from idr before its grace + * period starts, so we won't be looking up a cgroup while the + * cgroup is being freed. + */ + idr_remove(&cgrp->root->cgroup_idr, cgrp->id); + cgrp->id = -1; + dput(d); set_bit(CGRP_RELEASABLE, &parent->flags); @@ -4802,7 +4788,7 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss) /* * we shouldn't be called if the subsystem is in use, and the use of - * try_module_get in parse_cgroupfs_options should ensure that it + * try_module_get() in rebind_subsystems() should ensure that it * doesn't start being used while we're killing it off. */ BUG_ON(ss->root != &cgroup_dummy_root); @@ -4926,6 +4912,10 @@ int __init cgroup_init(void) BUG_ON(cgroup_init_root_id(&cgroup_dummy_root, 0, 1)); + err = idr_alloc(&cgroup_dummy_root.cgroup_idr, cgroup_dummy_top, + 0, 1, GFP_KERNEL); + BUG_ON(err < 0); + mutex_unlock(&cgroup_root_mutex); mutex_unlock(&cgroup_mutex);