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-rw-r--r--include/linux/cgroup-defs.h17
-rw-r--r--include/linux/cgroup.h17
-rw-r--r--include/trace/events/cgroup.h6
-rw-r--r--kernel/bpf/helpers.c2
-rw-r--r--kernel/bpf/local_storage.c2
-rw-r--r--kernel/cgroup/cgroup.c76
-rw-r--r--kernel/trace/blktrace.c4
-rw-r--r--net/core/filter.c4
8 files changed, 43 insertions, 85 deletions
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 4904b1ebd1ff..63097cb243cb 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -355,16 +355,6 @@ struct cgroup {
unsigned long flags; /* "unsigned long" so bitops work */
/*
- * idr allocated in-hierarchy ID.
- *
- * ID 0 is not used, the ID of the root cgroup is always 1, and a
- * new cgroup will be assigned with a smallest available ID.
- *
- * Allocating/Removing ID must be protected by cgroup_mutex.
- */
- int id;
-
- /*
* The depth this cgroup is at. The root is at depth zero and each
* step down the hierarchy increments the level. This along with
* ancestor_ids[] can determine whether a given cgroup is a
@@ -488,7 +478,7 @@ struct cgroup {
struct cgroup_freezer_state freezer;
/* ids of the ancestors at each level including self */
- int ancestor_ids[];
+ u64 ancestor_ids[];
};
/*
@@ -509,7 +499,7 @@ struct cgroup_root {
struct cgroup cgrp;
/* for cgrp->ancestor_ids[0] */
- int cgrp_ancestor_id_storage;
+ u64 cgrp_ancestor_id_storage;
/* Number of cgroups in the hierarchy, used only for /proc/cgroups */
atomic_t nr_cgrps;
@@ -520,9 +510,6 @@ struct cgroup_root {
/* Hierarchy-specific flags */
unsigned int flags;
- /* IDs for cgroups in this hierarchy */
- struct idr cgroup_idr;
-
/* The path to use for release notifications. */
char release_agent_path[PATH_MAX];
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 815fff49d555..d7ddebd0cdec 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -304,6 +304,11 @@ void css_task_iter_end(struct css_task_iter *it);
* Inline functions.
*/
+static inline u64 cgroup_id(struct cgroup *cgrp)
+{
+ return cgrp->kn->id;
+}
+
/**
* css_get - obtain a reference on the specified css
* @css: target css
@@ -565,7 +570,7 @@ static inline bool cgroup_is_descendant(struct cgroup *cgrp,
{
if (cgrp->root != ancestor->root || cgrp->level < ancestor->level)
return false;
- return cgrp->ancestor_ids[ancestor->level] == ancestor->id;
+ return cgrp->ancestor_ids[ancestor->level] == cgroup_id(ancestor);
}
/**
@@ -687,17 +692,13 @@ static inline void cgroup_kthread_ready(void)
current->no_cgroup_migration = 0;
}
-static inline u64 cgroup_get_kernfs_id(struct cgroup *cgrp)
-{
- return cgrp->kn->id;
-}
-
void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen);
#else /* !CONFIG_CGROUPS */
struct cgroup_subsys_state;
struct cgroup;
+static inline u64 cgroup_id(struct cgroup *cgrp) { return 1; }
static inline void css_get(struct cgroup_subsys_state *css) {}
static inline void css_put(struct cgroup_subsys_state *css) {}
static inline int cgroup_attach_task_all(struct task_struct *from,
@@ -717,10 +718,6 @@ static inline int cgroup_init_early(void) { return 0; }
static inline int cgroup_init(void) { return 0; }
static inline void cgroup_init_kthreadd(void) {}
static inline void cgroup_kthread_ready(void) {}
-static inline union u64 cgroup_get_kernfs_id(struct cgroup *cgrp)
-{
- return 0;
-}
static inline struct cgroup *cgroup_parent(struct cgroup *cgrp)
{
diff --git a/include/trace/events/cgroup.h b/include/trace/events/cgroup.h
index a566cc521476..7f42a3de59e6 100644
--- a/include/trace/events/cgroup.h
+++ b/include/trace/events/cgroup.h
@@ -66,7 +66,7 @@ DECLARE_EVENT_CLASS(cgroup,
TP_fast_assign(
__entry->root = cgrp->root->hierarchy_id;
- __entry->id = cgrp->id;
+ __entry->id = cgroup_id(cgrp);
__entry->level = cgrp->level;
__assign_str(path, path);
),
@@ -135,7 +135,7 @@ DECLARE_EVENT_CLASS(cgroup_migrate,
TP_fast_assign(
__entry->dst_root = dst_cgrp->root->hierarchy_id;
- __entry->dst_id = dst_cgrp->id;
+ __entry->dst_id = cgroup_id(dst_cgrp);
__entry->dst_level = dst_cgrp->level;
__assign_str(dst_path, path);
__entry->pid = task->pid;
@@ -179,7 +179,7 @@ DECLARE_EVENT_CLASS(cgroup_event,
TP_fast_assign(
__entry->root = cgrp->root->hierarchy_id;
- __entry->id = cgrp->id;
+ __entry->id = cgroup_id(cgrp);
__entry->level = cgrp->level;
__assign_str(path, path);
__entry->val = val;
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 912e761cd17a..cada974c9f4e 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -317,7 +317,7 @@ BPF_CALL_0(bpf_get_current_cgroup_id)
{
struct cgroup *cgrp = task_dfl_cgroup(current);
- return cgrp->kn->id;
+ return cgroup_id(cgrp);
}
const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index 5d867f6d7204..2ba750725cb2 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -569,7 +569,7 @@ void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
return;
storage->key.attach_type = type;
- storage->key.cgroup_inode_id = cgroup->kn->id;
+ storage->key.cgroup_inode_id = cgroup_id(cgroup);
map = storage->map;
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index b5dcbee5aa6c..c12dcf7dc432 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1308,10 +1308,7 @@ static void cgroup_exit_root_id(struct cgroup_root *root)
void cgroup_free_root(struct cgroup_root *root)
{
- if (root) {
- idr_destroy(&root->cgroup_idr);
- kfree(root);
- }
+ kfree(root);
}
static void cgroup_destroy_root(struct cgroup_root *root)
@@ -1917,7 +1914,6 @@ void init_cgroup_root(struct cgroup_fs_context *ctx)
atomic_set(&root->nr_cgrps, 1);
cgrp->root = root;
init_cgroup_housekeeping(cgrp);
- idr_init(&root->cgroup_idr);
root->flags = ctx->flags;
if (ctx->release_agent)
@@ -1938,12 +1934,6 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
lockdep_assert_held(&cgroup_mutex);
- ret = cgroup_idr_alloc(&root->cgroup_idr, root_cgrp, 1, 2, GFP_KERNEL);
- if (ret < 0)
- goto out;
- root_cgrp->id = ret;
- root_cgrp->ancestor_ids[0] = ret;
-
ret = percpu_ref_init(&root_cgrp->self.refcnt, css_release,
0, GFP_KERNEL);
if (ret)
@@ -1976,6 +1966,8 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask)
goto exit_root_id;
}
root_cgrp->kn = root->kf_root->kn;
+ WARN_ON_ONCE(cgroup_id(root_cgrp) != 1);
+ root_cgrp->ancestor_ids[0] = cgroup_id(root_cgrp);
ret = css_populate_dir(&root_cgrp->self);
if (ret)
@@ -3552,22 +3544,22 @@ static int cpu_stat_show(struct seq_file *seq, void *v)
#ifdef CONFIG_PSI
static int cgroup_io_pressure_show(struct seq_file *seq, void *v)
{
- struct cgroup *cgroup = seq_css(seq)->cgroup;
- struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi;
+ struct cgroup *cgrp = seq_css(seq)->cgroup;
+ struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;
return psi_show(seq, psi, PSI_IO);
}
static int cgroup_memory_pressure_show(struct seq_file *seq, void *v)
{
- struct cgroup *cgroup = seq_css(seq)->cgroup;
- struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi;
+ struct cgroup *cgrp = seq_css(seq)->cgroup;
+ struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;
return psi_show(seq, psi, PSI_MEM);
}
static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v)
{
- struct cgroup *cgroup = seq_css(seq)->cgroup;
- struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi;
+ struct cgroup *cgrp = seq_css(seq)->cgroup;
+ struct psi_group *psi = cgroup_id(cgrp) == 1 ? &psi_system : &cgrp->psi;
return psi_show(seq, psi, PSI_CPU);
}
@@ -4987,9 +4979,6 @@ static void css_release_work_fn(struct work_struct *work)
tcgrp->nr_dying_descendants--;
spin_unlock_irq(&css_set_lock);
- cgroup_idr_remove(&cgrp->root->cgroup_idr, cgrp->id);
- cgrp->id = -1;
-
/*
* There are two control paths which try to determine
* cgroup from dentry without going through kernfs -
@@ -5154,10 +5143,12 @@ err_free_css:
* it isn't associated with its kernfs_node and doesn't have the control
* mask applied.
*/
-static struct cgroup *cgroup_create(struct cgroup *parent)
+static struct cgroup *cgroup_create(struct cgroup *parent, const char *name,
+ umode_t mode)
{
struct cgroup_root *root = parent->root;
struct cgroup *cgrp, *tcgrp;
+ struct kernfs_node *kn;
int level = parent->level + 1;
int ret;
@@ -5177,15 +5168,13 @@ static struct cgroup *cgroup_create(struct cgroup *parent)
goto out_cancel_ref;
}
- /*
- * Temporarily set the pointer to NULL, so idr_find() won't return
- * a half-baked cgroup.
- */
- cgrp->id = cgroup_idr_alloc(&root->cgroup_idr, NULL, 2, 0, GFP_KERNEL);
- if (cgrp->id < 0) {
- ret = -ENOMEM;
+ /* create the directory */
+ kn = kernfs_create_dir(parent->kn, name, mode, cgrp);
+ if (IS_ERR(kn)) {
+ ret = PTR_ERR(kn);
goto out_stat_exit;
}
+ cgrp->kn = kn;
init_cgroup_housekeeping(cgrp);
@@ -5195,7 +5184,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent)
ret = psi_cgroup_alloc(cgrp);
if (ret)
- goto out_idr_free;
+ goto out_kernfs_remove;
ret = cgroup_bpf_inherit(cgrp);
if (ret)
@@ -5219,7 +5208,7 @@ static struct cgroup *cgroup_create(struct cgroup *parent)
spin_lock_irq(&css_set_lock);
for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) {
- cgrp->ancestor_ids[tcgrp->level] = tcgrp->id;
+ cgrp->ancestor_ids[tcgrp->level] = cgroup_id(tcgrp);
if (tcgrp != cgrp) {
tcgrp->nr_descendants++;
@@ -5249,12 +5238,6 @@ static struct cgroup *cgroup_create(struct cgroup *parent)
cgroup_get_live(parent);
/*
- * @cgrp is now fully operational. If something fails after this
- * point, it'll be released via the normal destruction path.
- */
- cgroup_idr_replace(&root->cgroup_idr, cgrp, cgrp->id);
-
- /*
* On the default hierarchy, a child doesn't automatically inherit
* subtree_control from the parent. Each is configured manually.
*/
@@ -5267,8 +5250,8 @@ static struct cgroup *cgroup_create(struct cgroup *parent)
out_psi_free:
psi_cgroup_free(cgrp);
-out_idr_free:
- cgroup_idr_remove(&root->cgroup_idr, cgrp->id);
+out_kernfs_remove:
+ kernfs_remove(cgrp->kn);
out_stat_exit:
if (cgroup_on_dfl(parent))
cgroup_rstat_exit(cgrp);
@@ -5305,7 +5288,6 @@ fail:
int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode)
{
struct cgroup *parent, *cgrp;
- struct kernfs_node *kn;
int ret;
/* do not accept '\n' to prevent making /proc/<pid>/cgroup unparsable */
@@ -5321,27 +5303,19 @@ int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode)
goto out_unlock;
}
- cgrp = cgroup_create(parent);
+ cgrp = cgroup_create(parent, name, mode);
if (IS_ERR(cgrp)) {
ret = PTR_ERR(cgrp);
goto out_unlock;
}
- /* create the directory */
- kn = kernfs_create_dir(parent->kn, name, mode, cgrp);
- if (IS_ERR(kn)) {
- ret = PTR_ERR(kn);
- goto out_destroy;
- }
- cgrp->kn = kn;
-
/*
* This extra ref will be put in cgroup_free_fn() and guarantees
* that @cgrp->kn is always accessible.
*/
- kernfs_get(kn);
+ kernfs_get(cgrp->kn);
- ret = cgroup_kn_set_ugid(kn);
+ ret = cgroup_kn_set_ugid(cgrp->kn);
if (ret)
goto out_destroy;
@@ -5356,7 +5330,7 @@ int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, umode_t mode)
TRACE_CGROUP_PATH(mkdir, cgrp);
/* let's create and online css's */
- kernfs_activate(kn);
+ kernfs_activate(cgrp->kn);
ret = 0;
goto out_unlock;
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index a7dac5b63f3f..475e29498bca 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -171,7 +171,7 @@ void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
blkcg = NULL;
#ifdef CONFIG_BLK_CGROUP
trace_note(bt, 0, BLK_TN_MESSAGE, buf, n,
- blkcg ? cgroup_get_kernfs_id(blkcg->css.cgroup) : 0);
+ blkcg ? cgroup_id(blkcg->css.cgroup) : 1);
#else
trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, 0);
#endif
@@ -759,7 +759,7 @@ static u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
if (!bio->bi_blkg)
return 0;
- return cgroup_get_kernfs_id(bio_blkcg(bio)->css.cgroup);
+ return cgroup_id(bio_blkcg(bio)->css.cgroup);
}
#else
u64 blk_trace_bio_get_cgid(struct request_queue *q, struct bio *bio)
diff --git a/net/core/filter.c b/net/core/filter.c
index b360a7beb6fc..caef7c74cad5 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4089,7 +4089,7 @@ BPF_CALL_1(bpf_skb_cgroup_id, const struct sk_buff *, skb)
return 0;
cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
- return cgrp->kn->id;
+ return cgroup_id(cgrp);
}
static const struct bpf_func_proto bpf_skb_cgroup_id_proto = {
@@ -4114,7 +4114,7 @@ BPF_CALL_2(bpf_skb_ancestor_cgroup_id, const struct sk_buff *, skb, int,
if (!ancestor)
return 0;
- return ancestor->kn->id;
+ return cgroup_id(ancestor);
}
static const struct bpf_func_proto bpf_skb_ancestor_cgroup_id_proto = {