static struct vmpressure *vmpressure_parent(struct vmpressure *vmpr)
{
struct cgroup_subsys_state *css = vmpressure_to_css(vmpr);
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
memcg = parent_mem_cgroup(memcg);
if (!memcg)
return NULL;
return memcg_to_vmpressure(memcg);
}
static u64 tcp_cgroup_read(struct cgroup_subsys_state *css, struct cftype *cft)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
u64 val;
switch (cft->private) {
case RES_LIMIT:
val = tcp_read_stat(memcg, RES_LIMIT, RES_COUNTER_MAX);
break;
case RES_USAGE:
val = tcp_read_usage(memcg);
break;
case RES_FAILCNT:
case RES_MAX_USAGE:
val = tcp_read_stat(memcg, cft->private, 0);
break;
default:
BUG();
}
return val;
}
static ssize_t tcp_cgroup_reset(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
struct mem_cgroup *memcg;
struct cg_proto *cg_proto;
memcg = mem_cgroup_from_css(of_css(of));
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return nbytes;
switch (of_cft(of)->private) {
case RES_MAX_USAGE:
res_counter_reset_max(&cg_proto->memory_allocated);
break;
case RES_FAILCNT:
res_counter_reset_failcnt(&cg_proto->memory_allocated);
break;
}
return nbytes;
}
static ssize_t tcp_cgroup_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
unsigned long long val;
int ret = 0;
buf = strstrip(buf);
switch (of_cft(of)->private) {
case RES_LIMIT:
/* see memcontrol.c */
ret = res_counter_memparse_write_strategy(buf, &val);
if (ret)
break;
ret = tcp_update_limit(memcg, val);
break;
default:
ret = -EINVAL;
break;
}
return ret ?: nbytes;
}
static int cgwb_create(struct backing_dev_info *bdi,
struct cgroup_subsys_state *memcg_css, gfp_t gfp)
{
struct mem_cgroup *memcg;
struct cgroup_subsys_state *blkcg_css;
struct blkcg *blkcg;
struct list_head *memcg_cgwb_list, *blkcg_cgwb_list;
struct bdi_writeback *wb;
unsigned long flags;
int ret = 0;
memcg = mem_cgroup_from_css(memcg_css);
blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys);
blkcg = css_to_blkcg(blkcg_css);
memcg_cgwb_list = mem_cgroup_cgwb_list(memcg);
blkcg_cgwb_list = &blkcg->cgwb_list;
/* look up again under lock and discard on blkcg mismatch */
spin_lock_irqsave(&cgwb_lock, flags);
wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id);
if (wb && wb->blkcg_css != blkcg_css) {
cgwb_kill(wb);
wb = NULL;
}
spin_unlock_irqrestore(&cgwb_lock, flags);
if (wb)
goto out_put;
/* need to create a new one */
wb = kmalloc(sizeof(*wb), gfp);
if (!wb)
return -ENOMEM;
ret = wb_init(wb, bdi, blkcg_css->id, gfp);
if (ret)
goto err_free;
ret = percpu_ref_init(&wb->refcnt, cgwb_release, 0, gfp);
if (ret)
goto err_wb_exit;
ret = fprop_local_init_percpu(&wb->memcg_completions, gfp);
if (ret)
goto err_ref_exit;
wb->memcg_css = memcg_css;
wb->blkcg_css = blkcg_css;
INIT_WORK(&wb->release_work, cgwb_release_workfn);
set_bit(WB_registered, &wb->state);
/*
* The root wb determines the registered state of the whole bdi and
* memcg_cgwb_list and blkcg_cgwb_list's next pointers indicate
* whether they're still online. Don't link @wb if any is dead.
* See wb_memcg_offline() and wb_blkcg_offline().
*/
ret = -ENODEV;
spin_lock_irqsave(&cgwb_lock, flags);
if (test_bit(WB_registered, &bdi->wb.state) &&
blkcg_cgwb_list->next && memcg_cgwb_list->next) {
/* we might have raced another instance of this function */
ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb);
if (!ret) {
atomic_inc(&bdi->usage_cnt);
list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list);
list_add(&wb->memcg_node, memcg_cgwb_list);
list_add(&wb->blkcg_node, blkcg_cgwb_list);
css_get(memcg_css);
css_get(blkcg_css);
}
}
spin_unlock_irqrestore(&cgwb_lock, flags);
if (ret) {
if (ret == -EEXIST)
ret = 0;
goto err_fprop_exit;
}
goto out_put;
err_fprop_exit:
fprop_local_destroy_percpu(&wb->memcg_completions);
err_ref_exit:
percpu_ref_exit(&wb->refcnt);
err_wb_exit:
wb_exit(wb);
err_free:
kfree(wb);
out_put:
css_put(blkcg_css);
return ret;
}
