Merge tag 'vfs-7.0-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:
 "The kernfs rbtree is keyed by (hash, ns, name) where the hash
  is seeded with the raw namespace pointer via init_name_hash(ns).

  The resulting hash values are exposed to userspace through
  readdir seek positions, and the pointer-based ordering in
  kernfs_name_compare() is observable through entry order.

  Switch from raw pointers to ns_common::ns_id for both hashing
  and comparison.

  A preparatory commit first replaces all const void * namespace
  parameters with const struct ns_common * throughout kernfs, sysfs,
  and kobject so the code can access ns->ns_id. Also compare the
  ns_id when hashes match in the rbtree to handle crafted collisions.

  Also fix eventpoll RCU grace period issue and a cachefiles refcount
  problem"

* tag 'vfs-7.0-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  kernfs: make directory seek namespace-aware
  kernfs: use namespace id instead of pointer for hashing and comparison
  kernfs: pass struct ns_common instead of const void * for namespace tags
  eventpoll: defer struct eventpoll free to RCU grace period
  cachefiles: fix incorrect dentry refcount in cachefiles_cull()

4 files changed, 40 insertions, 39 deletions

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 07624b682b08..b9740a397f55 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1181,24 +1181,24 @@ static void rx_queue_release(struct kobject *kobj)
 	netdev_put(queue->dev, &queue->dev_tracker);
 }
 
-static const void *rx_queue_namespace(const struct kobject *kobj)
+static const struct ns_common *rx_queue_namespace(const struct kobject *kobj)
 {
 	struct netdev_rx_queue *queue = to_rx_queue(kobj);
 	struct device *dev = &queue->dev->dev;
-	const void *ns = NULL;
 
 	if (dev->class && dev->class->namespace)
-		ns = dev->class->namespace(dev);
+		return dev->class->namespace(dev);
 
-	return ns;
+	return NULL;
 }
 
 static void rx_queue_get_ownership(const struct kobject *kobj,
 				   kuid_t *uid, kgid_t *gid)
 {
-	const struct net *net = rx_queue_namespace(kobj);
+	const struct ns_common *ns = rx_queue_namespace(kobj);
 
-	net_ns_get_ownership(net, uid, gid);
+	net_ns_get_ownership(ns ? container_of(ns, struct net, ns) : NULL,
+			     uid, gid);
 }
 
 static const struct kobj_type rx_queue_ktype = {
@@ -1931,24 +1931,24 @@ static void netdev_queue_release(struct kobject *kobj)
 	netdev_put(queue->dev, &queue->dev_tracker);
 }
 
-static const void *netdev_queue_namespace(const struct kobject *kobj)
+static const struct ns_common *netdev_queue_namespace(const struct kobject *kobj)
 {
 	struct netdev_queue *queue = to_netdev_queue(kobj);
 	struct device *dev = &queue->dev->dev;
-	const void *ns = NULL;
 
 	if (dev->class && dev->class->namespace)
-		ns = dev->class->namespace(dev);
+		return dev->class->namespace(dev);
 
-	return ns;
+	return NULL;
 }
 
 static void netdev_queue_get_ownership(const struct kobject *kobj,
 				       kuid_t *uid, kgid_t *gid)
 {
-	const struct net *net = netdev_queue_namespace(kobj);
+	const struct ns_common *ns = netdev_queue_namespace(kobj);
 
-	net_ns_get_ownership(net, uid, gid);
+	net_ns_get_ownership(ns ? container_of(ns, struct net, ns) : NULL,
+			     uid, gid);
 }
 
 static const struct kobj_type netdev_queue_ktype = {
@@ -2185,24 +2185,24 @@ static bool net_current_may_mount(void)
 	return ns_capable(net->user_ns, CAP_SYS_ADMIN);
 }
 
-static void *net_grab_current_ns(void)
+static struct ns_common *net_grab_current_ns(void)
 {
-	struct net *ns = current->nsproxy->net_ns;
+	struct net *net = current->nsproxy->net_ns;
 #ifdef CONFIG_NET_NS
-	if (ns)
-		refcount_inc(&ns->passive);
+	if (net)
+		refcount_inc(&net->passive);
 #endif
-	return ns;
+	return net ? to_ns_common(net) : NULL;
 }
 
-static const void *net_initial_ns(void)
+static const struct ns_common *net_initial_ns(void)
 {
-	return &init_net;
+	return to_ns_common(&init_net);
 }
 
-static const void *net_netlink_ns(struct sock *sk)
+static const struct ns_common *net_netlink_ns(struct sock *sk)
 {
-	return sock_net(sk);
+	return to_ns_common(sock_net(sk));
 }
 
 const struct kobj_ns_type_operations net_ns_type_operations = {
@@ -2252,11 +2252,11 @@ static void netdev_release(struct device *d)
 	kvfree(dev);
 }
 
-static const void *net_namespace(const struct device *d)
+static const struct ns_common *net_namespace(const struct device *d)
 {
 	const struct net_device *dev = to_net_dev(d);
 
-	return dev_net(dev);
+	return to_ns_common(dev_net(dev));
 }
 
 static void net_get_ownership(const struct device *d, kuid_t *uid, kgid_t *gid)
@@ -2402,14 +2402,14 @@ int netdev_change_owner(struct net_device *ndev, const struct net *net_old,
 }
 
 int netdev_class_create_file_ns(const struct class_attribute *class_attr,
-				const void *ns)
+				const struct ns_common *ns)
 {
 	return class_create_file_ns(&net_class, class_attr, ns);
 }
 EXPORT_SYMBOL(netdev_class_create_file_ns);
 
 void netdev_class_remove_file_ns(const struct class_attribute *class_attr,
-				 const void *ns)
+				 const struct ns_common *ns)
 {
 	class_remove_file_ns(&net_class, class_attr, ns);
 }
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 1057d16d5dd2..24aa10a1d0ea 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -540,12 +540,10 @@ void net_passive_dec(struct net *net)
 	}
 }
 
-void net_drop_ns(void *p)
+void net_drop_ns(struct ns_common *ns)
 {
-	struct net *net = (struct net *)p;
-
-	if (net)
-		net_passive_dec(net);
+	if (ns)
+		net_passive_dec(to_net_ns(ns));
 }
 
 struct net *copy_net_ns(u64 flags,
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index af8fac9cedd4..a90480f80154 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -6,6 +6,7 @@
 #include <linux/kobject.h>
 #include <linux/sunrpc/addr.h>
 #include <linux/sunrpc/xprtsock.h>
+#include <net/net_namespace.h>
 
 #include "sysfs.h"
 
@@ -553,20 +554,22 @@ static void rpc_sysfs_xprt_release(struct kobject *kobj)
 	kfree(xprt);
 }
 
-static const void *rpc_sysfs_client_namespace(const struct kobject *kobj)
+static const struct ns_common *rpc_sysfs_client_namespace(const struct kobject *kobj)
 {
-	return container_of(kobj, struct rpc_sysfs_client, kobject)->net;
+	return to_ns_common(container_of(kobj, struct rpc_sysfs_client,
+					 kobject)->net);
 }
 
-static const void *rpc_sysfs_xprt_switch_namespace(const struct kobject *kobj)
+static const struct ns_common *rpc_sysfs_xprt_switch_namespace(const struct kobject *kobj)
 {
-	return container_of(kobj, struct rpc_sysfs_xprt_switch, kobject)->net;
+	return to_ns_common(container_of(kobj, struct rpc_sysfs_xprt_switch,
+					 kobject)->net);
 }
 
-static const void *rpc_sysfs_xprt_namespace(const struct kobject *kobj)
+static const struct ns_common *rpc_sysfs_xprt_namespace(const struct kobject *kobj)
 {
-	return container_of(kobj, struct rpc_sysfs_xprt,
-			    kobject)->xprt->xprt_net;
+	return to_ns_common(container_of(kobj, struct rpc_sysfs_xprt,
+					 kobject)->xprt->xprt_net);
 }
 
 static struct kobj_attribute rpc_sysfs_clnt_version = __ATTR(rpc_version,
diff --git a/net/wireless/sysfs.c b/net/wireless/sysfs.c
index 2e0ea69b9604..0b9abe70d39d 100644
--- a/net/wireless/sysfs.c
+++ b/net/wireless/sysfs.c
@@ -154,11 +154,11 @@ static SIMPLE_DEV_PM_OPS(wiphy_pm_ops, wiphy_suspend, wiphy_resume);
 #define WIPHY_PM_OPS NULL
 #endif
 
-static const void *wiphy_namespace(const struct device *d)
+static const struct ns_common *wiphy_namespace(const struct device *d)
 {
 	struct wiphy *wiphy = container_of(d, struct wiphy, dev);
 
-	return wiphy_net(wiphy);
+	return to_ns_common(wiphy_net(wiphy));
 }
 
 struct class ieee80211_class = {