diff options
| -rw-r--r-- | block/blk-cgroup.c | 1 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 29 | ||||
| -rw-r--r-- | include/linux/cgroup_subsys.h | 24 | ||||
| -rw-r--r-- | kernel/cgroup.c | 284 | ||||
| -rw-r--r-- | net/core/netclassid_cgroup.c | 1 | ||||
| -rw-r--r-- | net/core/netprio_cgroup.c | 1 |
6 files changed, 32 insertions, 308 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 4e491d9b529..660d419918a 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -914,7 +914,6 @@ struct cgroup_subsys blkio_subsys = { .can_attach = blkcg_can_attach, .subsys_id = blkio_subsys_id, .base_cftypes = blkcg_files, - .module = THIS_MODULE, }; EXPORT_SYMBOL_GPL(blkio_subsys); diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 5c097596104..d842a737d44 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -37,28 +37,13 @@ extern void cgroup_post_fork(struct task_struct *p); extern void cgroup_exit(struct task_struct *p, int run_callbacks); extern int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry); -extern int cgroup_load_subsys(struct cgroup_subsys *ss); -extern void cgroup_unload_subsys(struct cgroup_subsys *ss); extern int proc_cgroup_show(struct seq_file *, void *); -/* - * Define the enumeration of all cgroup subsystems. - * - * We define ids for builtin subsystems and then modular ones. - */ +/* define the enumeration of all cgroup subsystems */ #define SUBSYS(_x) _x ## _subsys_id, enum cgroup_subsys_id { -#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option) #include <linux/cgroup_subsys.h> -#undef IS_SUBSYS_ENABLED - CGROUP_BUILTIN_SUBSYS_COUNT, - - __CGROUP_SUBSYS_TEMP_PLACEHOLDER = CGROUP_BUILTIN_SUBSYS_COUNT - 1, - -#define IS_SUBSYS_ENABLED(option) IS_MODULE(option) -#include <linux/cgroup_subsys.h> -#undef IS_SUBSYS_ENABLED CGROUP_SUBSYS_COUNT, }; #undef SUBSYS @@ -370,10 +355,9 @@ struct css_set { struct list_head cgrp_links; /* - * Set of subsystem states, one for each subsystem. This array - * is immutable after creation apart from the init_css_set - * during subsystem registration (at boot time) and modular subsystem - * loading/unloading. + * Set of subsystem states, one for each subsystem. This array is + * immutable after creation apart from the init_css_set during + * subsystem registration (at boot time). */ struct cgroup_subsys_state *subsys[CGROUP_SUBSYS_COUNT]; @@ -620,15 +604,10 @@ struct cgroup_subsys { /* base cftypes, automatically [de]registered with subsys itself */ struct cftype *base_cftypes; struct cftype_set base_cftset; - - /* should be defined only by modular subsystems */ - struct module *module; }; #define SUBSYS(_x) extern struct cgroup_subsys _x ## _subsys; -#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option) #include <linux/cgroup_subsys.h> -#undef IS_SUBSYS_ENABLED #undef SUBSYS /** diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h index 7b99d717411..11c42f6a25a 100644 --- a/include/linux/cgroup_subsys.h +++ b/include/linux/cgroup_subsys.h @@ -3,51 +3,51 @@ * * DO NOT ADD ANY SUBSYSTEM WITHOUT EXPLICIT ACKS FROM CGROUP MAINTAINERS. */ -#if IS_SUBSYS_ENABLED(CONFIG_CPUSETS) +#if IS_ENABLED(CONFIG_CPUSETS) SUBSYS(cpuset) #endif -#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_DEBUG) +#if IS_ENABLED(CONFIG_CGROUP_DEBUG) SUBSYS(debug) #endif -#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_SCHED) +#if IS_ENABLED(CONFIG_CGROUP_SCHED) SUBSYS(cpu_cgroup) #endif -#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_CPUACCT) +#if IS_ENABLED(CONFIG_CGROUP_CPUACCT) SUBSYS(cpuacct) #endif -#if IS_SUBSYS_ENABLED(CONFIG_MEMCG) +#if IS_ENABLED(CONFIG_MEMCG) SUBSYS(mem_cgroup) #endif -#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_DEVICE) +#if IS_ENABLED(CONFIG_CGROUP_DEVICE) SUBSYS(devices) #endif -#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_FREEZER) +#if IS_ENABLED(CONFIG_CGROUP_FREEZER) SUBSYS(freezer) #endif -#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_NET_CLASSID) +#if IS_ENABLED(CONFIG_CGROUP_NET_CLASSID) SUBSYS(net_cls) #endif -#if IS_SUBSYS_ENABLED(CONFIG_BLK_CGROUP) +#if IS_ENABLED(CONFIG_BLK_CGROUP) SUBSYS(blkio) #endif -#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_PERF) +#if IS_ENABLED(CONFIG_CGROUP_PERF) SUBSYS(perf) #endif -#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_NET_PRIO) +#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO) SUBSYS(net_prio) #endif -#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_HUGETLB) +#if IS_ENABLED(CONFIG_CGROUP_HUGETLB) SUBSYS(hugetlb) #endif /* diff --git a/kernel/cgroup.c b/kernel/cgroup.c index e2f46ba37f7..ccb16b47e29 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -47,7 +47,6 @@ #include <linux/string.h> #include <linux/sort.h> #include <linux/kmod.h> -#include <linux/module.h> #include <linux/delayacct.h> #include <linux/cgroupstats.h> #include <linux/hashtable.h> @@ -120,15 +119,9 @@ static struct workqueue_struct *cgroup_destroy_wq; */ static struct workqueue_struct *cgroup_pidlist_destroy_wq; -/* - * Generate an array of cgroup subsystem pointers. At boot time, this is - * populated with the built in subsystems, and modular subsystems are - * registered after that. The mutable section of this array is protected by - * cgroup_mutex. - */ +/* generate an array of cgroup subsystem pointers */ #define SUBSYS(_x) [_x ## _subsys_id] = &_x ## _subsys, -#define IS_SUBSYS_ENABLED(option) IS_BUILTIN(option) -static struct cgroup_subsys *cgroup_subsys[CGROUP_SUBSYS_COUNT] = { +static struct cgroup_subsys *cgroup_subsys[] = { #include <linux/cgroup_subsys.h> }; @@ -258,30 +251,13 @@ static int notify_on_release(const struct cgroup *cgrp) else /** - * for_each_subsys - iterate all loaded cgroup subsystems + * for_each_subsys - iterate all enabled cgroup subsystems * @ss: the iteration cursor * @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end - * - * Iterates through all loaded subsystems. Should be called under - * cgroup_mutex or cgroup_root_mutex. */ #define for_each_subsys(ss, ssid) \ - for (({ cgroup_assert_mutex_or_root_locked(); (ssid) = 0; }); \ - (ssid) < CGROUP_SUBSYS_COUNT; (ssid)++) \ - if (!((ss) = cgroup_subsys[(ssid)])) { } \ - else - -/** - * for_each_builtin_subsys - iterate all built-in cgroup subsystems - * @ss: the iteration cursor - * @i: the index of @ss, CGROUP_BUILTIN_SUBSYS_COUNT after reaching the end - * - * Bulit-in subsystems are always present and iteration itself doesn't - * require any synchronization. - */ -#define for_each_builtin_subsys(ss, i) \ - for ((i) = 0; (i) < CGROUP_BUILTIN_SUBSYS_COUNT && \ - (((ss) = cgroup_subsys[i]) || true); (i)++) + for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT && \ + (((ss) = cgroup_subsys[ssid]) || true); (ssid)++) /* iterate across the active hierarchies */ #define for_each_active_root(root) \ @@ -975,50 +951,24 @@ static void cgroup_d_remove_dir(struct dentry *dentry) remove_dir(dentry); } -/* - * Call with cgroup_mutex held. Drops reference counts on modules, including - * any duplicate ones that parse_cgroupfs_options took. If this function - * returns an error, no reference counts are touched. - */ static int rebind_subsystems(struct cgroupfs_root *root, unsigned long added_mask, unsigned removed_mask) { struct cgroup *cgrp = &root->top_cgroup; struct cgroup_subsys *ss; - 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) { - if (!(added_mask & (1 << i))) - continue; - - /* is the subsystem mounted elsewhere? */ - if (ss->root != &cgroup_dummy_root) { - ret = -EBUSY; - goto out_put; - } - - /* pin the module */ - if (!try_module_get(ss->module)) { - ret = -ENOENT; - goto out_put; - } - pinned |= 1 << i; - } - - /* subsys could be missing if unloaded between parsing and here */ - if (added_mask != pinned) { - ret = -ENOENT; - goto out_put; - } + for_each_subsys(ss, i) + if ((added_mask & (1 << i)) && ss->root != &cgroup_dummy_root) + return -EBUSY; ret = cgroup_populate_dir(cgrp, added_mask); if (ret) - goto out_put; + return ret; /* * Nothing can fail from this point on. Remove files for the @@ -1057,9 +1007,6 @@ static int rebind_subsystems(struct cgroupfs_root *root, RCU_INIT_POINTER(cgrp->subsys[i], NULL); cgroup_subsys[i]->root = &cgroup_dummy_root; - - /* subsystem is now free - drop reference on module */ - module_put(ss->module); root->subsys_mask &= ~bit; } } @@ -1071,12 +1018,6 @@ 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) @@ -4506,7 +4447,7 @@ static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry) return ret; } -static void __init_or_module cgroup_init_cftsets(struct cgroup_subsys *ss) +static void __init cgroup_init_cftsets(struct cgroup_subsys *ss) { INIT_LIST_HEAD(&ss->cftsets); @@ -4559,186 +4500,9 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss) BUG_ON(online_css(css)); mutex_unlock(&cgroup_mutex); - - /* this function shouldn't be used with modular subsystems, since they - * need to register a subsys_id, among other things */ - BUG_ON(ss->module); } /** - * cgroup_load_subsys: load and register a modular subsystem at runtime - * @ss: the subsystem to load - * - * This function should be called in a modular subsystem's initcall. If the - * subsystem is built as a module, it will be assigned a new subsys_id and set - * up for use. If the subsystem is built-in anyway, work is delegated to the - * simpler cgroup_init_subsys. - */ -int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss) -{ - struct cgroup_subsys_state *css; - int i, ret; - struct hlist_node *tmp; - struct css_set *cset; - unsigned long key; - - /* check name and function validity */ - if (ss->name == NULL || strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN || - ss->css_alloc == NULL || ss->css_free == NULL) - return -EINVAL; - - /* - * we don't support callbacks in modular subsystems. this check is - * before the ss->module check for consistency; a subsystem that could - * be a module should still have no callbacks even if the user isn't - * compiling it as one. - */ - if (ss->fork || ss->exit) - return -EINVAL; - - /* - * an optionally modular subsystem is built-in: we want to do nothing, - * since cgroup_init_subsys will have already taken care of it. - */ - if (ss->module == NULL) { - /* a sanity check */ - BUG_ON(cgroup_subsys[ss->subsys_id] != ss); - return 0; - } - - /* init base cftset */ - cgroup_init_cftsets(ss); - - mutex_lock(&cgroup_mutex); - mutex_lock(&cgroup_root_mutex); - cgroup_subsys[ss->subsys_id] = ss; - - /* - * no ss->css_alloc seems to need anything important in the ss - * struct, so this can happen first (i.e. before the dummy root - * attachment). - */ - css = ss->css_alloc(cgroup_css(cgroup_dummy_top, ss)); - if (IS_ERR(css)) { - /* failure case - need to deassign the cgroup_subsys[] slot. */ - cgroup_subsys[ss->subsys_id] = NULL; - mutex_unlock(&cgroup_root_mutex); - mutex_unlock(&cgroup_mutex); - return PTR_ERR(css); - } - - ss->root = &cgroup_dummy_root; - - /* our new subsystem will be attached to the dummy hierarchy. */ - init_css(css, ss, cgroup_dummy_top); - - /* - * Now we need to entangle the css into the existing css_sets. unlike - * in cgroup_init_subsys, there are now multiple css_sets, so each one - * will need a new pointer to it; done by iterating the css_set_table. - * furthermore, modifying the existing css_sets will corrupt the hash - * table state, so each changed css_set will need its hash recomputed. - * this is all done under the css_set_lock. - */ - write_lock(&css_set_lock); - hash_for_each_safe(css_set_table, i, tmp, cset, hlist) { - /* skip entries that we already rehashed */ - if (cset->subsys[ss->subsys_id]) - continue; - /* remove existing entry */ - hash_del(&cset->hlist); - /* set new value */ - cset->subsys[ss->subsys_id] = css; - /* recompute hash and restore entry */ - key = css_set_hash(cset->subsys); - hash_add(css_set_table, &cset->hlist, key); - } - write_unlock(&css_set_lock); - - ret = online_css(css); - if (ret) { - ss->css_free(css); - goto err_unload; - } - - /* success! */ - mutex_unlock(&cgroup_root_mutex); - mutex_unlock(&cgroup_mutex); - return 0; - -err_unload: - mutex_unlock(&cgroup_root_mutex); - mutex_unlock(&cgroup_mutex); - /* @ss can't be mounted here as try_module_get() would fail */ - cgroup_unload_subsys(ss); - return ret; -} -EXPORT_SYMBOL_GPL(cgroup_load_subsys); - -/** - * cgroup_unload_subsys: unload a modular subsystem - * @ss: the subsystem to unload - * - * This function should be called in a modular subsystem's exitcall. When this - * function is invoked, the refcount on the subsystem's module will be 0, so - * the subsystem will not be attached to any hierarchy. - */ -void cgroup_unload_subsys(struct cgroup_subsys *ss) -{ - struct cgrp_cset_link *link; - struct cgroup_subsys_state *css; - - BUG_ON(ss->module == NULL); - - /* - * we shouldn't be called if the subsystem is in use, and the use of - * 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); - - mutex_lock(&cgroup_mutex); - mutex_lock(&cgroup_root_mutex); - - css = cgroup_css(cgroup_dummy_top, ss); - if (css) - offline_css(css); - - /* deassign the subsys_id */ - cgroup_subsys[ss->subsys_id] = NULL; - - /* - * disentangle the css from all css_sets attached to the dummy - * top. as in loading, we need to pay our respects to the hashtable - * gods. - */ - write_lock(&css_set_lock); - list_for_each_entry(link, &cgroup_dummy_top->cset_links, cset_link) { - struct css_set *cset = link->cset; - unsigned long key; - - hash_del(&cset->hlist); - cset->subsys[ss->subsys_id] = NULL; - key = css_set_hash(cset->subsys); - hash_add(css_set_table, &cset->hlist, key); - } - write_unlock(&css_set_lock); - - /* - * remove subsystem's css from the cgroup_dummy_top and free it - - * need to free before marking as null because ss->css_free needs - * the cgrp->subsys pointer to find their state. - */ - if (css) - ss->css_free(css); - RCU_INIT_POINTER(cgroup_dummy_top->subsys[ss->subsys_id], NULL); - - mutex_unlock(&cgroup_root_mutex); - mutex_unlock(&cgroup_mutex); -} -EXPORT_SYMBOL_GPL(cgroup_unload_subsys); - -/** * cgroup_init_early - cgroup initialization at system boot * * Initialize cgroups at system boot, and initialize any @@ -4763,8 +4527,7 @@ int __init cgroup_init_early(void) list_add(&init_cgrp_cset_link.cset_link, &cgroup_dummy_top->cset_links); list_add(&init_cgrp_cset_link.cgrp_link, &init_css_set.cgrp_links); - /* at bootup time, we don't worry about modular subsystems */ - for_each_builtin_subsys(ss, i) { + for_each_subsys(ss, i) { BUG_ON(!ss->name); BUG_ON(strlen(ss->name) > MAX_CGROUP_TYPE_NAMELEN); BUG_ON(!ss->css_alloc); @@ -4797,7 +4560,7 @@ int __init cgroup_init(void) if (err) return err; - for_each_builtin_subsys(ss, i) { + for_each_subsys(ss, i) { if (!ss->early_init) cgroup_init_subsys(ss); } @@ -5032,15 +4795,7 @@ void cgroup_post_fork(struct task_struct *child) * and addition to css_set. */ if (need_forkexit_callback) { - /* - * fork/exit callbacks are supported only for builtin - * subsystems, and the builtin section of the subsys - * array is immutable, so we don't need to lock the - * subsys array here. On the other hand, modular section - * of the array can be freed at module unload, so we - * can't touch that. - */ - for_each_builtin_subsys(ss, i) + for_each_subsys(ss, i) if (ss->fork) ss->fork(child); } @@ -5105,11 +4860,8 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks) RCU_INIT_POINTER(tsk->cgroups, &init_css_set); if (run_callbacks && need_forkexit_callback) { - /* - * fork/exit callbacks are supported only for builtin - * subsystems, see cgroup_post_fork() for details. - */ - for_each_builtin_subsys(ss, i) { + /* see cgroup_post_fork() for details */ + for_each_subsys(ss, i) { if (ss->exit) { struct cgroup_subsys_state *old_css = cset->subsys[i]; struct cgroup_subsys_state *css = task_css(tsk, i); @@ -5228,11 +4980,7 @@ static int __init cgroup_disable(char *str) if (!*token) continue; - /* - * cgroup_disable, being at boot time, can't know about - * module subsystems, so we don't worry about them. - */ - for_each_builtin_subsys(ss, i) { + for_each_subsys(ss, i) { if (!strcmp(token, ss->name)) { ss->disabled = 1; printk(KERN_INFO "Disabling %s control group" diff --git a/net/core/netclassid_cgroup.c b/net/core/netclassid_cgroup.c index 9fc7f90d034..9e5ad5d74e6 100644 --- a/net/core/netclassid_cgroup.c +++ b/net/core/netclassid_cgroup.c @@ -110,5 +110,4 @@ struct cgroup_subsys net_cls_subsys = { .attach = cgrp_attach, .subsys_id = net_cls_subsys_id, .base_cftypes = ss_files, - .module = THIS_MODULE, }; diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index cc3a31e7dc0..857e1603f9b 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c @@ -252,7 +252,6 @@ struct cgroup_subsys net_prio_subsys = { .attach = net_prio_attach, .subsys_id = net_prio_subsys_id, .base_cftypes = ss_files, - .module = THIS_MODULE, }; static int netprio_device_event(struct notifier_block *unused, |