drm/amd/powerplay: incorrectly use of the function return value
[linux-2.6-block.git] / kernel / cgroup.c
index 86cb5c6e89320f28e17691c6d69e58c9dfde81fb..75c0ff00aca60d298062755539e83cbfeaffaaf2 100644 (file)
@@ -837,6 +837,8 @@ static void put_css_set_locked(struct css_set *cset)
 
 static void put_css_set(struct css_set *cset)
 {
+       unsigned long flags;
+
        /*
         * Ensure that the refcount doesn't hit zero while any readers
         * can see it. Similar to atomic_dec_and_lock(), but for an
@@ -845,9 +847,9 @@ static void put_css_set(struct css_set *cset)
        if (atomic_add_unless(&cset->refcount, -1, 1))
                return;
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irqsave(&css_set_lock, flags);
        put_css_set_locked(cset);
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irqrestore(&css_set_lock, flags);
 }
 
 /*
@@ -1070,11 +1072,11 @@ static struct css_set *find_css_set(struct css_set *old_cset,
 
        /* First see if we already have a cgroup group that matches
         * the desired set */
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        cset = find_existing_css_set(old_cset, cgrp, template);
        if (cset)
                get_css_set(cset);
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        if (cset)
                return cset;
@@ -1102,7 +1104,7 @@ static struct css_set *find_css_set(struct css_set *old_cset,
         * find_existing_css_set() */
        memcpy(cset->subsys, template, sizeof(cset->subsys));
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        /* Add reference counts and links from the new css_set. */
        list_for_each_entry(link, &old_cset->cgrp_links, cgrp_link) {
                struct cgroup *c = link->cgrp;
@@ -1128,7 +1130,7 @@ static struct css_set *find_css_set(struct css_set *old_cset,
                css_get(css);
        }
 
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        return cset;
 }
@@ -1192,7 +1194,7 @@ static void cgroup_destroy_root(struct cgroup_root *root)
         * Release all the links from cset_links to this hierarchy's
         * root cgroup
         */
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
 
        list_for_each_entry_safe(link, tmp_link, &cgrp->cset_links, cset_link) {
                list_del(&link->cset_link);
@@ -1200,7 +1202,7 @@ static void cgroup_destroy_root(struct cgroup_root *root)
                kfree(link);
        }
 
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        if (!list_empty(&root->root_list)) {
                list_del(&root->root_list);
@@ -1600,11 +1602,11 @@ static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask)
                ss->root = dst_root;
                css->cgroup = dcgrp;
 
-               spin_lock_bh(&css_set_lock);
+               spin_lock_irq(&css_set_lock);
                hash_for_each(css_set_table, i, cset, hlist)
                        list_move_tail(&cset->e_cset_node[ss->id],
                                       &dcgrp->e_csets[ss->id]);
-               spin_unlock_bh(&css_set_lock);
+               spin_unlock_irq(&css_set_lock);
 
                /* default hierarchy doesn't enable controllers by default */
                dst_root->subsys_mask |= 1 << ssid;
@@ -1640,10 +1642,10 @@ static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
        if (!buf)
                return -ENOMEM;
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        ns_cgroup = current_cgns_cgroup_from_root(kf_cgroot);
        len = kernfs_path_from_node(kf_node, ns_cgroup->kn, buf, PATH_MAX);
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        if (len >= PATH_MAX)
                len = -ERANGE;
@@ -1897,7 +1899,7 @@ static void cgroup_enable_task_cg_lists(void)
 {
        struct task_struct *p, *g;
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
 
        if (use_task_css_set_links)
                goto out_unlock;
@@ -1922,8 +1924,12 @@ static void cgroup_enable_task_cg_lists(void)
                 * entry won't be deleted though the process has exited.
                 * Do it while holding siglock so that we don't end up
                 * racing against cgroup_exit().
+                *
+                * Interrupts were already disabled while acquiring
+                * the css_set_lock, so we do not need to disable it
+                * again when acquiring the sighand->siglock here.
                 */
-               spin_lock_irq(&p->sighand->siglock);
+               spin_lock(&p->sighand->siglock);
                if (!(p->flags & PF_EXITING)) {
                        struct css_set *cset = task_css_set(p);
 
@@ -1932,11 +1938,11 @@ static void cgroup_enable_task_cg_lists(void)
                        list_add_tail(&p->cg_list, &cset->tasks);
                        get_css_set(cset);
                }
-               spin_unlock_irq(&p->sighand->siglock);
+               spin_unlock(&p->sighand->siglock);
        } while_each_thread(g, p);
        read_unlock(&tasklist_lock);
 out_unlock:
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 }
 
 static void init_cgroup_housekeeping(struct cgroup *cgrp)
@@ -2043,13 +2049,13 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
         * Link the root cgroup in this hierarchy into all the css_set
         * objects.
         */
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        hash_for_each(css_set_table, i, cset, hlist) {
                link_css_set(&tmp_links, cset, root_cgrp);
                if (css_set_populated(cset))
                        cgroup_update_populated(root_cgrp, true);
        }
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        BUG_ON(!list_empty(&root_cgrp->self.children));
        BUG_ON(atomic_read(&root->nr_cgrps) != 1);
@@ -2256,11 +2262,11 @@ out_mount:
                struct cgroup *cgrp;
 
                mutex_lock(&cgroup_mutex);
-               spin_lock_bh(&css_set_lock);
+               spin_lock_irq(&css_set_lock);
 
                cgrp = cset_cgroup_from_root(ns->root_cset, root);
 
-               spin_unlock_bh(&css_set_lock);
+               spin_unlock_irq(&css_set_lock);
                mutex_unlock(&cgroup_mutex);
 
                nsdentry = kernfs_node_dentry(cgrp->kn, dentry->d_sb);
@@ -2337,11 +2343,11 @@ char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
        char *ret;
 
        mutex_lock(&cgroup_mutex);
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
 
        ret = cgroup_path_ns_locked(cgrp, buf, buflen, ns);
 
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
        mutex_unlock(&cgroup_mutex);
 
        return ret;
@@ -2369,7 +2375,7 @@ char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
        char *path = NULL;
 
        mutex_lock(&cgroup_mutex);
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
 
        root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id);
 
@@ -2382,7 +2388,7 @@ char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
                        path = buf;
        }
 
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
        mutex_unlock(&cgroup_mutex);
        return path;
 }
@@ -2557,7 +2563,7 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
         * the new cgroup.  There are no failure cases after here, so this
         * is the commit point.
         */
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        list_for_each_entry(cset, &tset->src_csets, mg_node) {
                list_for_each_entry_safe(task, tmp_task, &cset->mg_tasks, cg_list) {
                        struct css_set *from_cset = task_css_set(task);
@@ -2568,7 +2574,7 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset,
                        put_css_set_locked(from_cset);
                }
        }
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        /*
         * Migration is committed, all target tasks are now on dst_csets.
@@ -2597,13 +2603,13 @@ out_cancel_attach:
                }
        } while_each_subsys_mask();
 out_release_tset:
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        list_splice_init(&tset->dst_csets, &tset->src_csets);
        list_for_each_entry_safe(cset, tmp_cset, &tset->src_csets, mg_node) {
                list_splice_tail_init(&cset->mg_tasks, &cset->tasks);
                list_del_init(&cset->mg_node);
        }
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
        return ret;
 }
 
@@ -2634,7 +2640,7 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets)
 
        lockdep_assert_held(&cgroup_mutex);
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        list_for_each_entry_safe(cset, tmp_cset, preloaded_csets, mg_preload_node) {
                cset->mg_src_cgrp = NULL;
                cset->mg_dst_cgrp = NULL;
@@ -2642,7 +2648,7 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets)
                list_del_init(&cset->mg_preload_node);
                put_css_set_locked(cset);
        }
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 }
 
 /**
@@ -2783,7 +2789,7 @@ static int cgroup_migrate(struct task_struct *leader, bool threadgroup,
         * already PF_EXITING could be freed from underneath us unless we
         * take an rcu_read_lock.
         */
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        rcu_read_lock();
        task = leader;
        do {
@@ -2792,7 +2798,7 @@ static int cgroup_migrate(struct task_struct *leader, bool threadgroup,
                        break;
        } while_each_thread(leader, task);
        rcu_read_unlock();
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        return cgroup_taskset_migrate(&tset, root);
 }
@@ -2816,7 +2822,7 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp,
                return -EBUSY;
 
        /* look up all src csets */
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        rcu_read_lock();
        task = leader;
        do {
@@ -2826,7 +2832,7 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp,
                        break;
        } while_each_thread(leader, task);
        rcu_read_unlock();
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        /* prepare dst csets and commit */
        ret = cgroup_migrate_prepare_dst(&preloaded_csets);
@@ -2859,9 +2865,9 @@ static int cgroup_procs_write_permission(struct task_struct *task,
                struct cgroup *cgrp;
                struct inode *inode;
 
-               spin_lock_bh(&css_set_lock);
+               spin_lock_irq(&css_set_lock);
                cgrp = task_cgroup_from_root(task, &cgrp_dfl_root);
-               spin_unlock_bh(&css_set_lock);
+               spin_unlock_irq(&css_set_lock);
 
                while (!cgroup_is_descendant(dst_cgrp, cgrp))
                        cgrp = cgroup_parent(cgrp);
@@ -2962,9 +2968,9 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
                if (root == &cgrp_dfl_root)
                        continue;
 
-               spin_lock_bh(&css_set_lock);
+               spin_lock_irq(&css_set_lock);
                from_cgrp = task_cgroup_from_root(from, root);
-               spin_unlock_bh(&css_set_lock);
+               spin_unlock_irq(&css_set_lock);
 
                retval = cgroup_attach_task(from_cgrp, tsk, false);
                if (retval)
@@ -3080,7 +3086,7 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
        percpu_down_write(&cgroup_threadgroup_rwsem);
 
        /* look up all csses currently attached to @cgrp's subtree */
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        cgroup_for_each_live_descendant_pre(dsct, d_css, cgrp) {
                struct cgrp_cset_link *link;
 
@@ -3088,14 +3094,14 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
                        cgroup_migrate_add_src(link->cset, dsct,
                                               &preloaded_csets);
        }
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        /* NULL dst indicates self on default hierarchy */
        ret = cgroup_migrate_prepare_dst(&preloaded_csets);
        if (ret)
                goto out_finish;
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        list_for_each_entry(src_cset, &preloaded_csets, mg_preload_node) {
                struct task_struct *task, *ntask;
 
@@ -3107,7 +3113,7 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
                list_for_each_entry_safe(task, ntask, &src_cset->tasks, cg_list)
                        cgroup_taskset_add(task, &tset);
        }
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        ret = cgroup_taskset_migrate(&tset, cgrp->root);
 out_finish:
@@ -3908,10 +3914,10 @@ static int cgroup_task_count(const struct cgroup *cgrp)
        int count = 0;
        struct cgrp_cset_link *link;
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        list_for_each_entry(link, &cgrp->cset_links, cset_link)
                count += atomic_read(&link->cset->refcount);
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
        return count;
 }
 
@@ -4249,7 +4255,7 @@ void css_task_iter_start(struct cgroup_subsys_state *css,
 
        memset(it, 0, sizeof(*it));
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
 
        it->ss = css->ss;
 
@@ -4262,7 +4268,7 @@ void css_task_iter_start(struct cgroup_subsys_state *css,
 
        css_task_iter_advance_css_set(it);
 
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 }
 
 /**
@@ -4280,7 +4286,7 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it)
                it->cur_task = NULL;
        }
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
 
        if (it->task_pos) {
                it->cur_task = list_entry(it->task_pos, struct task_struct,
@@ -4289,7 +4295,7 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it)
                css_task_iter_advance(it);
        }
 
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        return it->cur_task;
 }
@@ -4303,10 +4309,10 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it)
 void css_task_iter_end(struct css_task_iter *it)
 {
        if (it->cur_cset) {
-               spin_lock_bh(&css_set_lock);
+               spin_lock_irq(&css_set_lock);
                list_del(&it->iters_node);
                put_css_set_locked(it->cur_cset);
-               spin_unlock_bh(&css_set_lock);
+               spin_unlock_irq(&css_set_lock);
        }
 
        if (it->cur_task)
@@ -4338,10 +4344,10 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
        mutex_lock(&cgroup_mutex);
 
        /* all tasks in @from are being moved, all csets are source */
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        list_for_each_entry(link, &from->cset_links, cset_link)
                cgroup_migrate_add_src(link->cset, to, &preloaded_csets);
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        ret = cgroup_migrate_prepare_dst(&preloaded_csets);
        if (ret)
@@ -5063,6 +5069,7 @@ static void init_and_link_css(struct cgroup_subsys_state *css,
        memset(css, 0, sizeof(*css));
        css->cgroup = cgrp;
        css->ss = ss;
+       css->id = -1;
        INIT_LIST_HEAD(&css->sibling);
        INIT_LIST_HEAD(&css->children);
        css->serial_nr = css_serial_nr_next++;
@@ -5150,7 +5157,7 @@ static struct cgroup_subsys_state *css_create(struct cgroup *cgrp,
 
        err = cgroup_idr_alloc(&ss->css_idr, NULL, 2, 0, GFP_KERNEL);
        if (err < 0)
-               goto err_free_percpu_ref;
+               goto err_free_css;
        css->id = err;
 
        /* @css is ready to be brought online now, make it visible */
@@ -5174,9 +5181,6 @@ static struct cgroup_subsys_state *css_create(struct cgroup *cgrp,
 
 err_list_del:
        list_del_rcu(&css->sibling);
-       cgroup_idr_remove(&ss->css_idr, css->id);
-err_free_percpu_ref:
-       percpu_ref_exit(&css->refcnt);
 err_free_css:
        call_rcu(&css->rcu_head, css_free_rcu_fn);
        return ERR_PTR(err);
@@ -5451,10 +5455,10 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
         */
        cgrp->self.flags &= ~CSS_ONLINE;
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        list_for_each_entry(link, &cgrp->cset_links, cset_link)
                link->cset->dead = true;
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
 
        /* initiate massacre of all css's */
        for_each_css(css, ssid, cgrp)
@@ -5725,7 +5729,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
                goto out;
 
        mutex_lock(&cgroup_mutex);
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
 
        for_each_root(root) {
                struct cgroup_subsys *ss;
@@ -5778,7 +5782,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
 
        retval = 0;
 out_unlock:
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
        mutex_unlock(&cgroup_mutex);
        kfree(buf);
 out:
@@ -5923,13 +5927,13 @@ void cgroup_post_fork(struct task_struct *child)
        if (use_task_css_set_links) {
                struct css_set *cset;
 
-               spin_lock_bh(&css_set_lock);
+               spin_lock_irq(&css_set_lock);
                cset = task_css_set(current);
                if (list_empty(&child->cg_list)) {
                        get_css_set(cset);
                        css_set_move_task(child, NULL, cset, false);
                }
-               spin_unlock_bh(&css_set_lock);
+               spin_unlock_irq(&css_set_lock);
        }
 
        /*
@@ -5974,9 +5978,9 @@ void cgroup_exit(struct task_struct *tsk)
        cset = task_css_set(tsk);
 
        if (!list_empty(&tsk->cg_list)) {
-               spin_lock_bh(&css_set_lock);
+               spin_lock_irq(&css_set_lock);
                css_set_move_task(tsk, cset, NULL, false);
-               spin_unlock_bh(&css_set_lock);
+               spin_unlock_irq(&css_set_lock);
        } else {
                get_css_set(cset);
        }
@@ -6044,9 +6048,9 @@ static void cgroup_release_agent(struct work_struct *work)
        if (!pathbuf || !agentbuf)
                goto out;
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        path = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
        if (!path)
                goto out;
 
@@ -6306,12 +6310,12 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags,
                return ERR_PTR(-EPERM);
 
        mutex_lock(&cgroup_mutex);
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
 
        cset = task_css_set(current);
        get_css_set(cset);
 
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
        mutex_unlock(&cgroup_mutex);
 
        new_ns = alloc_cgroup_ns();
@@ -6435,7 +6439,7 @@ static int current_css_set_cg_links_read(struct seq_file *seq, void *v)
        if (!name_buf)
                return -ENOMEM;
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        rcu_read_lock();
        cset = rcu_dereference(current->cgroups);
        list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
@@ -6446,7 +6450,7 @@ static int current_css_set_cg_links_read(struct seq_file *seq, void *v)
                           c->root->hierarchy_id, name_buf);
        }
        rcu_read_unlock();
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
        kfree(name_buf);
        return 0;
 }
@@ -6457,7 +6461,7 @@ static int cgroup_css_links_read(struct seq_file *seq, void *v)
        struct cgroup_subsys_state *css = seq_css(seq);
        struct cgrp_cset_link *link;
 
-       spin_lock_bh(&css_set_lock);
+       spin_lock_irq(&css_set_lock);
        list_for_each_entry(link, &css->cgroup->cset_links, cset_link) {
                struct css_set *cset = link->cset;
                struct task_struct *task;
@@ -6480,7 +6484,7 @@ static int cgroup_css_links_read(struct seq_file *seq, void *v)
        overflow:
                seq_puts(seq, "  ...\n");
        }
-       spin_unlock_bh(&css_set_lock);
+       spin_unlock_irq(&css_set_lock);
        return 0;
 }