diff options
| -rw-r--r-- | block/blk-cgroup.c | 2 | ||||
| -rw-r--r-- | fs/bio.c | 2 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 14 | ||||
| -rw-r--r-- | kernel/cgroup.c | 40 | ||||
| -rw-r--r-- | kernel/cgroup_freezer.c | 4 | ||||
| -rw-r--r-- | kernel/cpuset.c | 6 | ||||
| -rw-r--r-- | kernel/events/core.c | 3 | ||||
| -rw-r--r-- | mm/hugetlb_cgroup.c | 2 | ||||
| -rw-r--r-- | mm/memcontrol.c | 46 |
9 files changed, 61 insertions, 58 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 1039fb9ff5f5..9f5bce33e6fe 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -185,7 +185,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, lockdep_assert_held(q->queue_lock); /* blkg holds a reference to blkcg */ - if (!css_tryget(&blkcg->css)) { + if (!css_tryget_online(&blkcg->css)) { ret = -EINVAL; goto err_free_blkg; } @@ -1970,7 +1970,7 @@ int bio_associate_current(struct bio *bio) /* associate blkcg if exists */ rcu_read_lock(); css = task_css(current, blkio_cgrp_id); - if (css && css_tryget(css)) + if (css && css_tryget_online(css)) bio->bi_css = css; rcu_read_unlock(); diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index bde44618d8c2..c5f3684ef557 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -95,16 +95,16 @@ static inline void css_get(struct cgroup_subsys_state *css) } /** - * css_tryget - try to obtain a reference on the specified css + * css_tryget_online - try to obtain a reference on the specified css if online * @css: target css * - * Obtain a reference on @css if it's alive. The caller naturally needs to - * ensure that @css is accessible but doesn't have to be holding a + * Obtain a reference on @css if it's online. The caller naturally needs + * to ensure that @css is accessible but doesn't have to be holding a * reference on it - IOW, RCU protected access is good enough for this * function. Returns %true if a reference count was successfully obtained; * %false otherwise. */ -static inline bool css_tryget(struct cgroup_subsys_state *css) +static inline bool css_tryget_online(struct cgroup_subsys_state *css) { if (css->flags & CSS_ROOT) return true; @@ -115,7 +115,7 @@ static inline bool css_tryget(struct cgroup_subsys_state *css) * css_put - put a css reference * @css: target css * - * Put a reference obtained via css_get() and css_tryget(). + * Put a reference obtained via css_get() and css_tryget_online(). */ static inline void css_put(struct cgroup_subsys_state *css) { @@ -905,8 +905,8 @@ void css_task_iter_end(struct css_task_iter *it); int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); -struct cgroup_subsys_state *css_tryget_from_dir(struct dentry *dentry, - struct cgroup_subsys *ss); +struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, + struct cgroup_subsys *ss); #else /* !CONFIG_CGROUPS */ diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 7633703e9baf..671d8a6dae37 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3771,7 +3771,7 @@ int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry) /* * We aren't being called from kernfs and there's no guarantee on - * @kn->priv's validity. For this and css_tryget_from_dir(), + * @kn->priv's validity. For this and css_tryget_online_from_dir(), * @kn->priv is RCU safe. Let's do the RCU dancing. */ rcu_read_lock(); @@ -4060,9 +4060,9 @@ err: * Implemented in kill_css(). * * 2. When the percpu_ref is confirmed to be visible as killed on all CPUs - * and thus css_tryget() is guaranteed to fail, the css can be offlined - * by invoking offline_css(). After offlining, the base ref is put. - * Implemented in css_killed_work_fn(). + * and thus css_tryget_online() is guaranteed to fail, the css can be + * offlined by invoking offline_css(). After offlining, the base ref is + * put. Implemented in css_killed_work_fn(). * * 3. When the percpu_ref reaches zero, the only possible remaining * accessors are inside RCU read sections. css_release() schedules the @@ -4386,7 +4386,7 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, /* * This is called when the refcnt of a css is confirmed to be killed. - * css_tryget() is now guaranteed to fail. + * css_tryget_online() is now guaranteed to fail. */ static void css_killed_work_fn(struct work_struct *work) { @@ -4398,8 +4398,8 @@ static void css_killed_work_fn(struct work_struct *work) mutex_lock(&cgroup_mutex); /* - * css_tryget() is guaranteed to fail now. Tell subsystems to - * initate destruction. + * css_tryget_online() is guaranteed to fail now. Tell subsystems + * to initate destruction. */ offline_css(css); @@ -4440,8 +4440,8 @@ static void css_killed_ref_fn(struct percpu_ref *ref) * * This function initiates destruction of @css by removing cgroup interface * files and putting its base reference. ->css_offline() will be invoked - * asynchronously once css_tryget() is guaranteed to fail and when the - * reference count reaches zero, @css will be released. + * asynchronously once css_tryget_online() is guaranteed to fail and when + * the reference count reaches zero, @css will be released. */ static void kill_css(struct cgroup_subsys_state *css) { @@ -4462,7 +4462,7 @@ static void kill_css(struct cgroup_subsys_state *css) /* * cgroup core guarantees that, by the time ->css_offline() is * invoked, no new css reference will be given out via - * css_tryget(). We can't simply call percpu_ref_kill() and + * css_tryget_online(). We can't simply call percpu_ref_kill() and * proceed to offlining css's because percpu_ref_kill() doesn't * guarantee that the ref is seen as killed on all CPUs on return. * @@ -4478,9 +4478,9 @@ static void kill_css(struct cgroup_subsys_state *css) * * css's make use of percpu refcnts whose killing latency shouldn't be * exposed to userland and are RCU protected. Also, cgroup core needs to - * guarantee that css_tryget() won't succeed by the time ->css_offline() is - * invoked. To satisfy all the requirements, destruction is implemented in - * the following two steps. + * guarantee that css_tryget_online() won't succeed by the time + * ->css_offline() is invoked. To satisfy all the requirements, + * destruction is implemented in the following two steps. * * s1. Verify @cgrp can be destroyed and mark it dying. Remove all * userland visible parts and start killing the percpu refcnts of @@ -4574,9 +4574,9 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) /* * There are two control paths which try to determine cgroup from * dentry without going through kernfs - cgroupstats_build() and - * css_tryget_from_dir(). Those are supported by RCU protecting - * clearing of cgrp->kn->priv backpointer, which should happen - * after all files under it have been removed. + * css_tryget_online_from_dir(). Those are supported by RCU + * protecting clearing of cgrp->kn->priv backpointer, which should + * happen after all files under it have been removed. */ kernfs_remove(cgrp->kn); /* @cgrp has an extra ref on its kn */ RCU_INIT_POINTER(*(void __rcu __force **)&cgrp->kn->priv, NULL); @@ -5173,7 +5173,7 @@ static int __init cgroup_disable(char *str) __setup("cgroup_disable=", cgroup_disable); /** - * css_tryget_from_dir - get corresponding css from the dentry of a cgroup dir + * css_tryget_online_from_dir - get corresponding css from a cgroup dentry * @dentry: directory dentry of interest * @ss: subsystem of interest * @@ -5181,8 +5181,8 @@ __setup("cgroup_disable=", cgroup_disable); * to get the corresponding css and return it. If such css doesn't exist * or can't be pinned, an ERR_PTR value is returned. */ -struct cgroup_subsys_state *css_tryget_from_dir(struct dentry *dentry, - struct cgroup_subsys *ss) +struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, + struct cgroup_subsys *ss) { struct kernfs_node *kn = kernfs_node_from_dentry(dentry); struct cgroup_subsys_state *css = NULL; @@ -5204,7 +5204,7 @@ struct cgroup_subsys_state *css_tryget_from_dir(struct dentry *dentry, if (cgrp) css = cgroup_css(cgrp, ss); - if (!css || !css_tryget(css)) + if (!css || !css_tryget_online(css)) css = ERR_PTR(-ENOENT); rcu_read_unlock(); diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 345628c78b5b..0398f7e9ac81 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -304,7 +304,7 @@ static int freezer_read(struct seq_file *m, void *v) /* update states bottom-up */ css_for_each_descendant_post(pos, css) { - if (!css_tryget(pos)) + if (!css_tryget_online(pos)) continue; rcu_read_unlock(); @@ -404,7 +404,7 @@ static void freezer_change_state(struct freezer *freezer, bool freeze) struct freezer *pos_f = css_freezer(pos); struct freezer *parent = parent_freezer(pos_f); - if (!css_tryget(pos)) + if (!css_tryget_online(pos)) continue; rcu_read_unlock(); diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 7c0e8da59e26..37ca0a5c226d 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -872,7 +872,7 @@ static void update_tasks_cpumask_hier(struct cpuset *root_cs, bool update_root) continue; } } - if (!css_tryget(&cp->css)) + if (!css_tryget_online(&cp->css)) continue; rcu_read_unlock(); @@ -1108,7 +1108,7 @@ static void update_tasks_nodemask_hier(struct cpuset *root_cs, bool update_root) continue; } } - if (!css_tryget(&cp->css)) + if (!css_tryget_online(&cp->css)) continue; rcu_read_unlock(); @@ -2153,7 +2153,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work) rcu_read_lock(); cpuset_for_each_descendant_pre(cs, pos_css, &top_cpuset) { - if (cs == &top_cpuset || !css_tryget(&cs->css)) + if (cs == &top_cpuset || !css_tryget_online(&cs->css)) continue; rcu_read_unlock(); diff --git a/kernel/events/core.c b/kernel/events/core.c index f83a71a3e46d..077968d19b8a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -607,7 +607,8 @@ static inline int perf_cgroup_connect(int fd, struct perf_event *event, if (!f.file) return -EBADF; - css = css_tryget_from_dir(f.file->f_dentry, &perf_event_cgrp_subsys); + css = css_tryget_online_from_dir(f.file->f_dentry, + &perf_event_cgrp_subsys); if (IS_ERR(css)) { ret = PTR_ERR(css); goto out; diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index 595d7fd795e1..372f1adca491 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c @@ -181,7 +181,7 @@ int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, again: rcu_read_lock(); h_cg = hugetlb_cgroup_from_task(current); - if (!css_tryget(&h_cg->css)) { + if (!css_tryget_online(&h_cg->css)) { rcu_read_unlock(); goto again; } diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c3f82f69ef58..5cf3246314a2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -567,7 +567,8 @@ void sock_update_memcg(struct sock *sk) memcg = mem_cgroup_from_task(current); cg_proto = sk->sk_prot->proto_cgroup(memcg); if (!mem_cgroup_is_root(memcg) && - memcg_proto_active(cg_proto) && css_tryget(&memcg->css)) { + memcg_proto_active(cg_proto) && + css_tryget_online(&memcg->css)) { sk->sk_cgrp = cg_proto; } rcu_read_unlock(); @@ -834,7 +835,7 @@ retry: */ __mem_cgroup_remove_exceeded(mz->memcg, mz, mctz); if (!res_counter_soft_limit_excess(&mz->memcg->res) || - !css_tryget(&mz->memcg->css)) + !css_tryget_online(&mz->memcg->css)) goto retry; done: return mz; @@ -1076,7 +1077,7 @@ static struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm) memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); if (unlikely(!memcg)) memcg = root_mem_cgroup; - } while (!css_tryget(&memcg->css)); + } while (!css_tryget_online(&memcg->css)); rcu_read_unlock(); return memcg; } @@ -1113,7 +1114,8 @@ skip_node: */ if (next_css) { if ((next_css == &root->css) || - ((next_css->flags & CSS_ONLINE) && css_tryget(next_css))) + ((next_css->flags & CSS_ONLINE) && + css_tryget_online(next_css))) return mem_cgroup_from_css(next_css); prev_css = next_css; @@ -1159,7 +1161,7 @@ mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter, * would be returned all the time. */ if (position && position != root && - !css_tryget(&position->css)) + !css_tryget_online(&position->css)) position = NULL; } return position; @@ -2785,9 +2787,9 @@ static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, /* * A helper function to get mem_cgroup from ID. must be called under - * rcu_read_lock(). The caller is responsible for calling css_tryget if - * the mem_cgroup is used for charging. (dropping refcnt from swap can be - * called against removed memcg.) + * rcu_read_lock(). The caller is responsible for calling + * css_tryget_online() if the mem_cgroup is used for charging. (dropping + * refcnt from swap can be called against removed memcg.) */ static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) { @@ -2810,14 +2812,14 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) lock_page_cgroup(pc); if (PageCgroupUsed(pc)) { memcg = pc->mem_cgroup; - if (memcg && !css_tryget(&memcg->css)) + if (memcg && !css_tryget_online(&memcg->css)) memcg = NULL; } else if (PageSwapCache(page)) { ent.val = page_private(page); id = lookup_swap_cgroup_id(ent); rcu_read_lock(); memcg = mem_cgroup_lookup(id); - if (memcg && !css_tryget(&memcg->css)) + if (memcg && !css_tryget_online(&memcg->css)) memcg = NULL; rcu_read_unlock(); } @@ -3473,7 +3475,7 @@ struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep, } /* The corresponding put will be done in the workqueue. */ - if (!css_tryget(&memcg->css)) + if (!css_tryget_online(&memcg->css)) goto out; rcu_read_unlock(); @@ -4246,8 +4248,8 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent) memcg = mem_cgroup_lookup(id); if (memcg) { /* - * We uncharge this because swap is freed. - * This memcg can be obsolete one. We avoid calling css_tryget + * We uncharge this because swap is freed. This memcg can + * be obsolete one. We avoid calling css_tryget_online(). */ if (!mem_cgroup_is_root(memcg)) res_counter_uncharge(&memcg->memsw, PAGE_SIZE); @@ -5840,10 +5842,10 @@ static void kmem_cgroup_css_offline(struct mem_cgroup *memcg) * which is then paired with css_put during uncharge resp. here. * * Although this might sound strange as this path is called from - * css_offline() when the referencemight have dropped down to 0 - * and shouldn't be incremented anymore (css_tryget would fail) - * we do not have other options because of the kmem allocations - * lifetime. + * css_offline() when the referencemight have dropped down to 0 and + * shouldn't be incremented anymore (css_tryget_online() would + * fail) we do not have other options because of the kmem + * allocations lifetime. */ css_get(&memcg->css); @@ -6051,8 +6053,8 @@ static int memcg_write_event_control(struct cgroup_subsys_state *css, * automatically removed on cgroup destruction but the removal is * asynchronous, so take an extra ref on @css. */ - cfile_css = css_tryget_from_dir(cfile.file->f_dentry->d_parent, - &memory_cgrp_subsys); + cfile_css = css_tryget_online_from_dir(cfile.file->f_dentry->d_parent, + &memory_cgrp_subsys); ret = -EINVAL; if (IS_ERR(cfile_css)) goto out_put_cfile; @@ -6496,7 +6498,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) /* * XXX: css_offline() would be where we should reparent all * memory to prepare the cgroup for destruction. However, - * memcg does not do css_tryget() and res_counter charging + * memcg does not do css_tryget_online() and res_counter charging * under the same RCU lock region, which means that charging * could race with offlining. Offlining only happens to * cgroups with no tasks in them but charges can show up @@ -6510,9 +6512,9 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css) * lookup_swap_cgroup_id() * rcu_read_lock() * mem_cgroup_lookup() - * css_tryget() + * css_tryget_online() * rcu_read_unlock() - * disable css_tryget() + * disable css_tryget_online() * call_rcu() * offline_css() * reparent_charges() |