[PATCH] cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers

From: Kamalesh Babulal
Date: Fri Mar 03 2023 - 04:54:01 EST

Replace mutex_[un]lock() with cgroup_[un]lock() wrappers to stay
consistent across cgroup core and other subsystem code, while
operating on the cgroup_mutex.

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@xxxxxxxxxx>
---
kernel/bpf/cgroup.c | 38 ++++++++++++------------
kernel/bpf/cgroup_iter.c | 4 +--
kernel/bpf/local_storage.c | 4 +--
kernel/cgroup/cgroup-v1.c | 16 +++++-----
kernel/cgroup/cgroup.c | 60 +++++++++++++++++++-------------------
5 files changed, 61 insertions(+), 61 deletions(-)

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index bf2fdb33fb31..3458701dcb28 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -173,11 +173,11 @@ void bpf_cgroup_atype_put(int cgroup_atype)
{
int i = cgroup_atype - CGROUP_LSM_START;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
if (--cgroup_lsm_atype[i].refcnt <= 0)
cgroup_lsm_atype[i].attach_btf_id = 0;
WARN_ON_ONCE(cgroup_lsm_atype[i].refcnt < 0);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
}
#else
static enum cgroup_bpf_attach_type
@@ -282,7 +282,7 @@ static void cgroup_bpf_release(struct work_struct *work)

unsigned int atype;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

for (atype = 0; atype < ARRAY_SIZE(cgrp->bpf.progs); atype++) {
struct hlist_head *progs = &cgrp->bpf.progs[atype];
@@ -315,7 +315,7 @@ static void cgroup_bpf_release(struct work_struct *work)
bpf_cgroup_storage_free(storage);
}

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
cgroup_bpf_put(p);
@@ -729,9 +729,9 @@ static int cgroup_bpf_attach(struct cgroup *cgrp,
{
int ret;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
ret = __cgroup_bpf_attach(cgrp, prog, replace_prog, link, type, flags);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return ret;
}

@@ -831,7 +831,7 @@ static int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *new_prog,

cg_link = container_of(link, struct bpf_cgroup_link, link);

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
/* link might have been auto-released by dying cgroup, so fail */
if (!cg_link->cgroup) {
ret = -ENOLINK;
@@ -843,7 +843,7 @@ static int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *new_prog,
}
ret = __cgroup_bpf_replace(cg_link->cgroup, cg_link, new_prog);
out_unlock:
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return ret;
}

@@ -1009,9 +1009,9 @@ static int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
{
int ret;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
ret = __cgroup_bpf_detach(cgrp, prog, NULL, type);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return ret;
}

@@ -1120,9 +1120,9 @@ static int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
{
int ret;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
ret = __cgroup_bpf_query(cgrp, attr, uattr);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return ret;
}

@@ -1189,11 +1189,11 @@ static void bpf_cgroup_link_release(struct bpf_link *link)
if (!cg_link->cgroup)
return;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

/* re-check cgroup under lock again */
if (!cg_link->cgroup) {
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return;
}

@@ -1205,7 +1205,7 @@ static void bpf_cgroup_link_release(struct bpf_link *link)
cg = cg_link->cgroup;
cg_link->cgroup = NULL;

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

cgroup_put(cg);
}
@@ -1232,10 +1232,10 @@ static void bpf_cgroup_link_show_fdinfo(const struct bpf_link *link,
container_of(link, struct bpf_cgroup_link, link);
u64 cg_id = 0;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
if (cg_link->cgroup)
cg_id = cgroup_id(cg_link->cgroup);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

seq_printf(seq,
"cgroup_id:\t%llu\n"
@@ -1251,10 +1251,10 @@ static int bpf_cgroup_link_fill_link_info(const struct bpf_link *link,
container_of(link, struct bpf_cgroup_link, link);
u64 cg_id = 0;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
if (cg_link->cgroup)
cg_id = cgroup_id(cg_link->cgroup);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

info->cgroup.cgroup_id = cg_id;
info->cgroup.attach_type = cg_link->type;
diff --git a/kernel/bpf/cgroup_iter.c b/kernel/bpf/cgroup_iter.c
index 06989d278846..810378f04fbc 100644
--- a/kernel/bpf/cgroup_iter.c
+++ b/kernel/bpf/cgroup_iter.c
@@ -58,7 +58,7 @@ static void *cgroup_iter_seq_start(struct seq_file *seq, loff_t *pos)
{
struct cgroup_iter_priv *p = seq->private;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

/* cgroup_iter doesn't support read across multiple sessions. */
if (*pos > 0) {
@@ -89,7 +89,7 @@ static void cgroup_iter_seq_stop(struct seq_file *seq, void *v)
{
struct cgroup_iter_priv *p = seq->private;

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

/* pass NULL to the prog for post-processing */
if (!v) {
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index e90d9f63edc5..9bceefee14d5 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -333,14 +333,14 @@ static void cgroup_storage_map_free(struct bpf_map *_map)
struct list_head *storages = &map->list;
struct bpf_cgroup_storage *storage, *stmp;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

list_for_each_entry_safe(storage, stmp, storages, list_map) {
bpf_cgroup_storage_unlink(storage);
bpf_cgroup_storage_free(storage);
}

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

WARN_ON(!RB_EMPTY_ROOT(&map->root));
WARN_ON(!list_empty(&map->list));
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 52bb5a74a23b..aeef06c465ef 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -58,7 +58,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
struct cgroup_root *root;
int retval = 0;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
cgroup_attach_lock(true);
for_each_root(root) {
struct cgroup *from_cgrp;
@@ -72,7 +72,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
break;
}
cgroup_attach_unlock(true);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

return retval;
}
@@ -106,7 +106,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
if (ret)
return ret;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

percpu_down_write(&cgroup_threadgroup_rwsem);

@@ -145,7 +145,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
out_err:
cgroup_migrate_finish(&mgctx);
percpu_up_write(&cgroup_threadgroup_rwsem);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return ret;
}

@@ -847,13 +847,13 @@ static int cgroup1_rename(struct kernfs_node *kn, struct kernfs_node *new_parent
kernfs_break_active_protection(new_parent);
kernfs_break_active_protection(kn);

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

ret = kernfs_rename(kn, new_parent, new_name_str);
if (!ret)
TRACE_CGROUP_PATH(rename, cgrp);

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

kernfs_unbreak_active_protection(kn);
kernfs_unbreak_active_protection(new_parent);
@@ -1119,7 +1119,7 @@ int cgroup1_reconfigure(struct fs_context *fc)
trace_cgroup_remount(root);

out_unlock:
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return ret;
}

@@ -1246,7 +1246,7 @@ int cgroup1_get_tree(struct fs_context *fc)
if (!ret && !percpu_ref_tryget_live(&ctx->root->cgrp.self.refcnt))
ret = 1; /* restart */

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

if (!ret)
ret = cgroup_do_get_tree(fc);
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 935e8121b21e..83ea13f2ccb1 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1391,7 +1391,7 @@ static void cgroup_destroy_root(struct cgroup_root *root)
cgroup_favor_dynmods(root, false);
cgroup_exit_root_id(root);

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

cgroup_rstat_exit(cgrp);
kernfs_destroy_root(root->kf_root);
@@ -1625,7 +1625,7 @@ void cgroup_kn_unlock(struct kernfs_node *kn)
else
cgrp = kn->parent->priv;

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

kernfs_unbreak_active_protection(kn);
cgroup_put(cgrp);
@@ -1670,7 +1670,7 @@ struct cgroup *cgroup_kn_lock_live(struct kernfs_node *kn, bool drain_offline)
if (drain_offline)
cgroup_lock_and_drain_offline(cgrp);
else
- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

if (!cgroup_is_dead(cgrp))
return cgrp;
@@ -2167,13 +2167,13 @@ int cgroup_do_get_tree(struct fs_context *fc)
struct super_block *sb = fc->root->d_sb;
struct cgroup *cgrp;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
spin_lock_irq(&css_set_lock);

cgrp = cset_cgroup_from_root(ctx->ns->root_cset, ctx->root);

spin_unlock_irq(&css_set_lock);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

nsdentry = kernfs_node_dentry(cgrp->kn, sb);
dput(fc->root);
@@ -2356,13 +2356,13 @@ int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
{
int ret;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
spin_lock_irq(&css_set_lock);

ret = cgroup_path_ns_locked(cgrp, buf, buflen, ns);

spin_unlock_irq(&css_set_lock);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

return ret;
}
@@ -2388,7 +2388,7 @@ int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
int hierarchy_id = 1;
int ret;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
spin_lock_irq(&css_set_lock);

root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id);
@@ -2402,7 +2402,7 @@ int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
}

spin_unlock_irq(&css_set_lock);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return ret;
}
EXPORT_SYMBOL_GPL(task_cgroup_path);
@@ -3111,7 +3111,7 @@ void cgroup_lock_and_drain_offline(struct cgroup *cgrp)
int ssid;

restart:
- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

cgroup_for_each_live_descendant_post(dsct, d_css, cgrp) {
for_each_subsys(ss, ssid) {
@@ -3125,7 +3125,7 @@ void cgroup_lock_and_drain_offline(struct cgroup *cgrp)
prepare_to_wait(&dsct->offline_waitq, &wait,
TASK_UNINTERRUPTIBLE);

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
schedule();
finish_wait(&dsct->offline_waitq, &wait);

@@ -4374,9 +4374,9 @@ int cgroup_rm_cftypes(struct cftype *cfts)
if (!(cfts[0].flags & __CFTYPE_ADDED))
return -ENOENT;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
ret = cgroup_rm_cftypes_locked(cfts);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return ret;
}

@@ -4408,14 +4408,14 @@ static int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts)
if (ret)
return ret;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

list_add_tail(&cfts->node, &ss->cfts);
ret = cgroup_apply_cftypes(cfts, true);
if (ret)
cgroup_rm_cftypes_locked(cfts);

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
return ret;
}

@@ -5385,7 +5385,7 @@ static void css_release_work_fn(struct work_struct *work)
struct cgroup_subsys *ss = css->ss;
struct cgroup *cgrp = css->cgroup;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

css->flags |= CSS_RELEASED;
list_del_rcu(&css->sibling);
@@ -5426,7 +5426,7 @@ static void css_release_work_fn(struct work_struct *work)
NULL);
}

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

INIT_RCU_WORK(&css->destroy_rwork, css_free_rwork_fn);
queue_rcu_work(cgroup_destroy_wq, &css->destroy_rwork);
@@ -5774,7 +5774,7 @@ static void css_killed_work_fn(struct work_struct *work)
struct cgroup_subsys_state *css =
container_of(work, struct cgroup_subsys_state, destroy_work);

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

do {
offline_css(css);
@@ -5783,7 +5783,7 @@ static void css_killed_work_fn(struct work_struct *work)
css = css->parent;
} while (css && atomic_dec_and_test(&css->online_cnt));

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
}

/* css kill confirmation processing requires process context, bounce */
@@ -5967,7 +5967,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early)

pr_debug("Initializing cgroup subsys %s\n", ss->name);

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

idr_init(&ss->css_idr);
INIT_LIST_HEAD(&ss->cfts);
@@ -6011,7 +6011,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early)

BUG_ON(online_css(css));

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
}

/**
@@ -6071,7 +6071,7 @@ int __init cgroup_init(void)

get_user_ns(init_cgroup_ns.user_ns);

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

/*
* Add init_css_set to the hash table so that dfl_root can link to
@@ -6082,7 +6082,7 @@ int __init cgroup_init(void)

BUG_ON(cgroup_setup_root(&cgrp_dfl_root, 0));

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

for_each_subsys(ss, ssid) {
if (ss->early_init) {
@@ -6134,9 +6134,9 @@ int __init cgroup_init(void)
if (ss->bind)
ss->bind(init_css_set.subsys[ssid]);

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
css_populate_dir(init_css_set.subsys[ssid]);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
}

/* init_css_set.subsys[] has been updated, re-hash */
@@ -6241,7 +6241,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
if (!buf)
goto out;

- mutex_lock(&cgroup_mutex);
+ cgroup_lock();
spin_lock_irq(&css_set_lock);

for_each_root(root) {
@@ -6296,7 +6296,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns,
retval = 0;
out_unlock:
spin_unlock_irq(&css_set_lock);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
kfree(buf);
out:
return retval;
@@ -6380,7 +6380,7 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)
struct file *f;

if (kargs->flags & CLONE_INTO_CGROUP)
- mutex_lock(&cgroup_mutex);
+ cgroup_lock();

cgroup_threadgroup_change_begin(current);

@@ -6455,7 +6455,7 @@ static int cgroup_css_set_fork(struct kernel_clone_args *kargs)

err:
cgroup_threadgroup_change_end(current);
- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();
if (f)
fput(f);
if (dst_cgrp)
@@ -6482,7 +6482,7 @@ static void cgroup_css_set_put_fork(struct kernel_clone_args *kargs)
struct cgroup *cgrp = kargs->cgrp;
struct css_set *cset = kargs->cset;

- mutex_unlock(&cgroup_mutex);
+ cgroup_unlock();

if (cset) {
put_css_set(cset);
--
2.34.3