cgroup: pass around cgroup_subsys_state instead of cgroup in subsystem methods

[linux-2.6-block.git] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 4234428f1014dc8e3800a48c6883a316d0880938..271d9a5cde5ffdc2a32b316cce10bb48fa6b7d7f 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -853,8 +853,11 @@ static void cgroup_free_fn(struct work_struct *work)
        /*
         * Release the subsystem state objects.
         */
-       for_each_root_subsys(cgrp->root, ss)
-               ss->css_free(cgrp);
+       for_each_root_subsys(cgrp->root, ss) {
+               struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+
+               ss->css_free(css);
+       }
 
        cgrp->root->number_of_cgroups--;
        mutex_unlock(&cgroup_mutex);
@@ -1056,7 +1059,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
                        list_move(&ss->sibling, &root->subsys_list);
                        ss->root = root;
                        if (ss->bind)
-                               ss->bind(cgrp);
+                               ss->bind(cgrp->subsys[i]);
 
                        /* refcount was already taken, and we're keeping it */
                        root->subsys_mask |= bit;
@@ -1066,7 +1069,7 @@ static int rebind_subsystems(struct cgroupfs_root *root,
                        BUG_ON(cgrp->subsys[i]->cgroup != cgrp);
 
                        if (ss->bind)
-                               ss->bind(cgroup_dummy_top);
+                               ss->bind(cgroup_dummy_top->subsys[i]);
                        cgroup_dummy_top->subsys[i]->cgroup = cgroup_dummy_top;
                        cgrp->subsys[i] = NULL;
                        cgroup_subsys[i]->root = &cgroup_dummy_root;
@@ -2049,8 +2052,10 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
         * step 1: check that we can legitimately attach to the cgroup.
         */
        for_each_root_subsys(root, ss) {
+               struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+
                if (ss->can_attach) {
-                       retval = ss->can_attach(cgrp, &tset);
+                       retval = ss->can_attach(css, &tset);
                        if (retval) {
                                failed_ss = ss;
                                goto out_cancel_attach;
@@ -2089,8 +2094,10 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
         * step 4: do subsystem attach callbacks.
         */
        for_each_root_subsys(root, ss) {
+               struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+
                if (ss->attach)
-                       ss->attach(cgrp, &tset);
+                       ss->attach(css, &tset);
        }
 
        /*
@@ -2109,10 +2116,12 @@ out_put_css_set_refs:
 out_cancel_attach:
        if (retval) {
                for_each_root_subsys(root, ss) {
+                       struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
+
                        if (ss == failed_ss)
                                break;
                        if (ss->cancel_attach)
-                               ss->cancel_attach(cgrp, &tset);
+                               ss->cancel_attach(css, &tset);
                }
        }
 out_free_group_list:
@@ -4206,14 +4215,15 @@ static void init_cgroup_css(struct cgroup_subsys_state *css,
 /* invoke ->css_online() on a new CSS and mark it online if successful */
 static int online_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
 {
+       struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
        int ret = 0;
 
        lockdep_assert_held(&cgroup_mutex);
 
        if (ss->css_online)
-               ret = ss->css_online(cgrp);
+               ret = ss->css_online(css);
        if (!ret)
-               cgrp->subsys[ss->subsys_id]->flags |= CSS_ONLINE;
+               css->flags |= CSS_ONLINE;
        return ret;
 }
 
@@ -4228,9 +4238,9 @@ static void offline_css(struct cgroup_subsys *ss, struct cgroup *cgrp)
                return;
 
        if (ss->css_offline)
-               ss->css_offline(cgrp);
+               ss->css_offline(css);
 
-       cgrp->subsys[ss->subsys_id]->flags &= ~CSS_ONLINE;
+       css->flags &= ~CSS_ONLINE;
 }
 
 /*
@@ -4305,7 +4315,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
        for_each_root_subsys(root, ss) {
                struct cgroup_subsys_state *css;
 
-               css = ss->css_alloc(cgrp);
+               css = ss->css_alloc(parent->subsys[ss->subsys_id]);
                if (IS_ERR(css)) {
                        err = PTR_ERR(css);
                        goto err_free_all;
@@ -4313,7 +4323,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
 
                err = percpu_ref_init(&css->refcnt, css_release);
                if (err) {
-                       ss->css_free(cgrp);
+                       ss->css_free(css);
                        goto err_free_all;
                }
 
@@ -4386,7 +4396,7 @@ err_free_all:
 
                if (css) {
                        percpu_ref_cancel_init(&css->refcnt);
-                       ss->css_free(cgrp);
+                       ss->css_free(css);
                }
        }
        mutex_unlock(&cgroup_mutex);
@@ -4641,7 +4651,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
        /* Create the top cgroup state for this subsystem */
        list_add(&ss->sibling, &cgroup_dummy_root.subsys_list);
        ss->root = &cgroup_dummy_root;
-       css = ss->css_alloc(cgroup_dummy_top);
+       css = ss->css_alloc(cgroup_dummy_top->subsys[ss->subsys_id]);
        /* We don't handle early failures gracefully */
        BUG_ON(IS_ERR(css));
        init_cgroup_css(css, ss, cgroup_dummy_top);
@@ -4720,7 +4730,7 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
         * struct, so this can happen first (i.e. before the dummy root
         * attachment).
         */
-       css = ss->css_alloc(cgroup_dummy_top);
+       css = ss->css_alloc(cgroup_dummy_top->subsys[ss->subsys_id]);
        if (IS_ERR(css)) {
                /* failure case - need to deassign the cgroup_subsys[] slot. */
                cgroup_subsys[ss->subsys_id] = NULL;
@@ -4836,7 +4846,7 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
         * the cgrp->subsys pointer to find their state. note that this
         * also takes care of freeing the css_id.
         */
-       ss->css_free(cgroup_dummy_top);
+       ss->css_free(cgroup_dummy_top->subsys[ss->subsys_id]);
        cgroup_dummy_top->subsys[ss->subsys_id] = NULL;
 
        mutex_unlock(&cgroup_mutex);
@@ -5192,10 +5202,10 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
                 */
                for_each_builtin_subsys(ss, i) {
                        if (ss->exit) {
-                               struct cgroup *old_cgrp = cset->subsys[i]->cgroup;
-                               struct cgroup *cgrp = task_cgroup(tsk, i);
+                               struct cgroup_subsys_state *old_css = cset->subsys[i];
+                               struct cgroup_subsys_state *css = task_css(tsk, i);
 
-                               ss->exit(cgrp, old_cgrp, tsk);
+                               ss->exit(css, old_css, tsk);
                        }
                }
        }
@@ -5529,7 +5539,8 @@ struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id)
 }
 
 #ifdef CONFIG_CGROUP_DEBUG
-static struct cgroup_subsys_state *debug_css_alloc(struct cgroup *cgrp)
+static struct cgroup_subsys_state *
+debug_css_alloc(struct cgroup_subsys_state *parent_css)
 {
        struct cgroup_subsys_state *css = kzalloc(sizeof(*css), GFP_KERNEL);
 
@@ -5539,9 +5550,9 @@ static struct cgroup_subsys_state *debug_css_alloc(struct cgroup *cgrp)
        return css;
 }
 
-static void debug_css_free(struct cgroup *cgrp)
+static void debug_css_free(struct cgroup_subsys_state *css)
 {
-       kfree(cgrp->subsys[debug_subsys_id]);
+       kfree(css);
 }
 
 static u64 debug_taskcount_read(struct cgroup *cgrp, struct cftype *cft)