diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index e1c705fdfa7c531c0aaa8c3148853e2bcc8b83ba..db2e147e069fe52555bd8f8d39c2cd1e28341934 100644
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -752,107 +752,54 @@ static inline void cgroup_threadgroup_change_end(struct task_struct *tsk) {}
* sock_cgroup_data is embedded at sock->sk_cgrp_data and contains
* per-socket cgroup information except for memcg association.
*
- * On legacy hierarchies, net_prio and net_cls controllers directly set
- * attributes on each sock which can then be tested by the network layer.
- * On the default hierarchy, each sock is associated with the cgroup it was
- * created in and the networking layer can match the cgroup directly.
- *
- * To avoid carrying all three cgroup related fields separately in sock,
- * sock_cgroup_data overloads (prioidx, classid) and the cgroup pointer.
- * On boot, sock_cgroup_data records the cgroup that the sock was created
- * in so that cgroup2 matches can be made; however, once either net_prio or
- * net_cls starts being used, the area is overridden to carry prioidx and/or
- * classid. The two modes are distinguished by whether the lowest bit is
- * set. Clear bit indicates cgroup pointer while set bit prioidx and
- * classid.
- *
- * While userland may start using net_prio or net_cls at any time, once
- * either is used, cgroup2 matching no longer works. There is no reason to
- * mix the two and this is in line with how legacy and v2 compatibility is
- * handled. On mode switch, cgroup references which are already being
- * pointed to by socks may be leaked. While this can be remedied by adding
- * synchronization around sock_cgroup_data, given that the number of leaked
- * cgroups is bound and highly unlikely to be high, this seems to be the
- * better trade-off.
+ * On legacy hierarchies, net_prio and net_cls controllers directly
+ * set attributes on each sock which can then be tested by the network
+ * layer. On the default hierarchy, each sock is associated with the
+ * cgroup it was created in and the networking layer can match the
+ * cgroup directly.
*/
struct sock_cgroup_data {
- union {
-#ifdef __LITTLE_ENDIAN
- struct {
- u8 is_data : 1;
- u8 no_refcnt : 1;
- u8 unused : 6;
- u8 padding;
- u16 prioidx;
- u32 classid;
- } __packed;
-#else
- struct {
- u32 classid;
- u16 prioidx;
- u8 padding;
- u8 unused : 6;
- u8 no_refcnt : 1;
- u8 is_data : 1;
- } __packed;
+ struct cgroup *cgroup; /* v2 */
+#ifdef CONFIG_CGROUP_NET_CLASSID
+ u32 classid; /* v1 */
+#endif
+#ifdef CONFIG_CGROUP_NET_PRIO
+ u16 prioidx; /* v1 */
#endif
- u64 val;
- };
};
-/*
- * There's a theoretical window where the following accessors race with
- * updaters and return part of the previous pointer as the prioidx or
- * classid. Such races are short-lived and the result isn't critical.
- */
static inline u16 sock_cgroup_prioidx(const struct sock_cgroup_data *skcd)
{
- /* fallback to 1 which is always the ID of the root cgroup */
- return (skcd->is_data & 1) ? skcd->prioidx : 1;
+#ifdef CONFIG_CGROUP_NET_PRIO
+ return READ_ONCE(skcd->prioidx);
+#else
+ return 1;
+#endif
}
static inline u32 sock_cgroup_classid(const struct sock_cgroup_data *skcd)
{
- /* fallback to 0 which is the unconfigured default classid */
- return (skcd->is_data & 1) ? skcd->classid : 0;
+#ifdef CONFIG_CGROUP_NET_CLASSID
+ return READ_ONCE(skcd->classid);
+#else
+ return 0;
+#endif
}
-/*
- * If invoked concurrently, the updaters may clobber each other. The
- * caller is responsible for synchronization.
- */
static inline void sock_cgroup_set_prioidx(struct sock_cgroup_data *skcd,
u16 prioidx)
{
- struct sock_cgroup_data skcd_buf = {{ .val = READ_ONCE(skcd->val) }};
-
- if (sock_cgroup_prioidx(&skcd_buf) == prioidx)
- return;
-
- if (!(skcd_buf.is_data & 1)) {
- skcd_buf.val = 0;
- skcd_buf.is_data = 1;
- }
-
- skcd_buf.prioidx = prioidx;
- WRITE_ONCE(skcd->val, skcd_buf.val); /* see sock_cgroup_ptr() */
+#ifdef CONFIG_CGROUP_NET_PRIO
+ WRITE_ONCE(skcd->prioidx, prioidx);
+#endif
}
static inline void sock_cgroup_set_classid(struct sock_cgroup_data *skcd,
u32 classid)
{
- struct sock_cgroup_data skcd_buf = {{ .val = READ_ONCE(skcd->val) }};
-
- if (sock_cgroup_classid(&skcd_buf) == classid)
- return;
-
- if (!(skcd_buf.is_data & 1)) {
- skcd_buf.val = 0;
- skcd_buf.is_data = 1;
- }
-
- skcd_buf.classid = classid;
- WRITE_ONCE(skcd->val, skcd_buf.val); /* see sock_cgroup_ptr() */
+#ifdef CONFIG_CGROUP_NET_CLASSID
+ WRITE_ONCE(skcd->classid, classid);
+#endif
}
#else /* CONFIG_SOCK_CGROUP_DATA */
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 7bf60454a31361f3a0dd8b24fca91a743c8eaead..75c151413fda8c9ae1436983932ad7b09c3fda23 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -829,33 +829,13 @@ static inline void cgroup_account_cputime_field(struct task_struct *task,
*/
#ifdef CONFIG_SOCK_CGROUP_DATA
-#if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
-extern spinlock_t cgroup_sk_update_lock;
-#endif
-
-void cgroup_sk_alloc_disable(void);
void cgroup_sk_alloc(struct sock_cgroup_data *skcd);
void cgroup_sk_clone(struct sock_cgroup_data *skcd);
void cgroup_sk_free(struct sock_cgroup_data *skcd);
static inline struct cgroup *sock_cgroup_ptr(struct sock_cgroup_data *skcd)
{
-#if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
- unsigned long v;
-
- /*
- * @skcd->val is 64bit but the following is safe on 32bit too as we
- * just need the lower ulong to be written and read atomically.
- */
- v = READ_ONCE(skcd->val);
-
- if (v & 3)
- return &cgrp_dfl_root.cgrp;
-
- return (struct cgroup *)(unsigned long)v ?: &cgrp_dfl_root.cgrp;
-#else
- return (struct cgroup *)(unsigned long)skcd->val;
-#endif
+ return skcd->cgroup;
}
#else /* CONFIG_CGROUP_DATA */
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 881ce1470bebad74af7f37c8ae6b6579dd433cb8..8afa8690d288cc4daf023a2ef158cba7574c39da 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6572,74 +6572,44 @@ int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v)
*/
#ifdef CONFIG_SOCK_CGROUP_DATA
-#if defined(CONFIG_CGROUP_NET_PRIO) || defined(CONFIG_CGROUP_NET_CLASSID)
-
-DEFINE_SPINLOCK(cgroup_sk_update_lock);
-static bool cgroup_sk_alloc_disabled __read_mostly;
-
-void cgroup_sk_alloc_disable(void)
-{
- if (cgroup_sk_alloc_disabled)
- return;
- pr_info("cgroup: disabling cgroup2 socket matching due to net_prio or net_cls activation\n");
- cgroup_sk_alloc_disabled = true;
-}
-
-#else
-
-#define cgroup_sk_alloc_disabled false
-
-#endif
-
void cgroup_sk_alloc(struct sock_cgroup_data *skcd)
{
- if (cgroup_sk_alloc_disabled) {
- skcd->no_refcnt = 1;
- return;
- }
-
/* Don't associate the sock with unrelated interrupted task's cgroup. */
if (in_interrupt())
return;
rcu_read_lock();
-
while (true) {
struct css_set *cset;
cset = task_css_set(current);
if (likely(cgroup_tryget(cset->dfl_cgrp))) {
- skcd->val = (unsigned long)cset->dfl_cgrp;
+ skcd->cgroup = cset->dfl_cgrp;
cgroup_bpf_get(cset->dfl_cgrp);
break;
}
cpu_relax();
}
-
rcu_read_unlock();
}
void cgroup_sk_clone(struct sock_cgroup_data *skcd)
{
- if (skcd->val) {
- if (skcd->no_refcnt)
- return;
- /*
- * We might be cloning a socket which is left in an empty
- * cgroup and the cgroup might have already been rmdir'd.
- * Don't use cgroup_get_live().
- */
- cgroup_get(sock_cgroup_ptr(skcd));
- cgroup_bpf_get(sock_cgroup_ptr(skcd));
- }
+ struct cgroup *cgrp = sock_cgroup_ptr(skcd);
+
+ /*
+ * We might be cloning a socket which is left in an empty
+ * cgroup and the cgroup might have already been rmdir'd.
+ * Don't use cgroup_get_live().
+ */
+ cgroup_get(cgrp);
+ cgroup_bpf_get(cgrp);
}
void cgroup_sk_free(struct sock_cgroup_data *skcd)
{
struct cgroup *cgrp = sock_cgroup_ptr(skcd);
- if (skcd->no_refcnt)
- return;
cgroup_bpf_put(cgrp);
cgroup_put(cgrp);
}
diff --git a/net/core/netclassid_cgroup.c b/net/core/netclassid_cgroup.c
index b49c57d35a88e62915fe1534e082f7a912197bbe..1a6a86693b745984dbc3fe0c3b39d30042a47186 100644
--- a/net/core/netclassid_cgroup.c
+++ b/net/core/netclassid_cgroup.c
@@ -71,11 +71,8 @@ static int update_classid_sock(const void *v, struct file *file, unsigned n)
struct update_classid_context *ctx = (void *)v;
struct socket *sock = sock_from_file(file);
- if (sock) {
- spin_lock(&cgroup_sk_update_lock);
+ if (sock)
sock_cgroup_set_classid(&sock->sk->sk_cgrp_data, ctx->classid);
- spin_unlock(&cgroup_sk_update_lock);
- }
if (--ctx->batch == 0) {
ctx->batch = UPDATE_CLASSID_BATCH;
return n + 1;
@@ -121,8 +118,6 @@ static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
struct css_task_iter it;
struct task_struct *p;
- cgroup_sk_alloc_disable();
-
cs->classid = (u32)value;
css_task_iter_start(css, 0, &it);
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index 99a431c56f230b3655ffec56b7e4e2a7f24871a6..8456dfbe2eb40b371901c1e753acf8513262ac41 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -207,8 +207,6 @@ static ssize_t write_priomap(struct kernfs_open_file *of,
if (!dev)
return -ENODEV;
- cgroup_sk_alloc_disable();
-
rtnl_lock();
ret = netprio_set_prio(of_css(of), dev, prio);
@@ -221,12 +219,10 @@ static ssize_t write_priomap(struct kernfs_open_file *of,
static int update_netprio(const void *v, struct file *file, unsigned n)
{
struct socket *sock = sock_from_file(file);
- if (sock) {
- spin_lock(&cgroup_sk_update_lock);
+
+ if (sock)
sock_cgroup_set_prioidx(&sock->sk->sk_cgrp_data,
(unsigned long)v);
- spin_unlock(&cgroup_sk_update_lock);
- }
return 0;
}
@@ -235,8 +231,6 @@ static void net_prio_attach(struct cgroup_taskset *tset)
struct task_struct *p;
struct cgroup_subsys_state *css;
- cgroup_sk_alloc_disable();
-
cgroup_taskset_for_each(p, css, tset) {
void *v = (void *)(unsigned long)css->id;