1 files changed, 54 insertions, 19 deletions

diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 824c258143a3..b6eedf7650da 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -8,21 +8,46 @@
 #include <linux/refcount.h>
 #include <net/sock.h>
 
-void unix_inflight(struct user_struct *user, struct file *fp);
-void unix_notinflight(struct user_struct *user, struct file *fp);
-void unix_destruct_scm(struct sk_buff *skb);
-void io_uring_destruct_scm(struct sk_buff *skb);
+#if IS_ENABLED(CONFIG_UNIX)
+struct unix_sock *unix_get_socket(struct file *filp);
+#else
+static inline struct unix_sock *unix_get_socket(struct file *filp)
+{
+	return NULL;
+}
+#endif
+
+extern unsigned int unix_tot_inflight;
+void unix_add_edges(struct scm_fp_list *fpl, struct unix_sock *receiver);
+void unix_del_edges(struct scm_fp_list *fpl);
+void unix_update_edges(struct unix_sock *receiver);
+int unix_prepare_fpl(struct scm_fp_list *fpl);
+void unix_destroy_fpl(struct scm_fp_list *fpl);
 void unix_gc(void);
-void wait_for_unix_gc(void);
-struct sock *unix_get_socket(struct file *filp);
+void wait_for_unix_gc(struct scm_fp_list *fpl);
+
+struct unix_vertex {
+	struct list_head edges;
+	struct list_head entry;
+	struct list_head scc_entry;
+	unsigned long out_degree;
+	unsigned long index;
+	unsigned long scc_index;
+};
+
+struct unix_edge {
+	struct unix_sock *predecessor;
+	struct unix_sock *successor;
+	struct list_head vertex_entry;
+	struct list_head stack_entry;
+};
+
 struct sock *unix_peer_get(struct sock *sk);
 
 #define UNIX_HASH_MOD	(256 - 1)
 #define UNIX_HASH_SIZE	(256 * 2)
 #define UNIX_HASH_BITS	8
 
-extern unsigned int unix_tot_inflight;
-
 struct unix_address {
 	refcount_t	refcnt;
 	int		len;
@@ -42,16 +67,11 @@ struct unix_skb_parms {
 
 struct scm_stat {
 	atomic_t nr_fds;
+	unsigned long nr_unix_fds;
 };
 
 #define UNIXCB(skb)	(*(struct unix_skb_parms *)&((skb)->cb))
 
-#define unix_state_lock(s)	spin_lock(&unix_sk(s)->lock)
-#define unix_state_unlock(s)	spin_unlock(&unix_sk(s)->lock)
-#define unix_state_lock_nested(s) \
-				spin_lock_nested(&unix_sk(s)->lock, \
-				SINGLE_DEPTH_NESTING)
-
 /* The AF_UNIX socket */
 struct unix_sock {
 	/* WARNING: sk has to be the first member */
@@ -60,12 +80,9 @@ struct unix_sock {
 	struct path		path;
 	struct mutex		iolock, bindlock;
 	struct sock		*peer;
-	struct list_head	link;
-	atomic_long_t		inflight;
+	struct sock		*listener;
+	struct unix_vertex	*vertex;
 	spinlock_t		lock;
-	unsigned long		gc_flags;
-#define UNIX_GC_CANDIDATE	0
-#define UNIX_GC_MAYBE_CYCLE	1
 	struct socket_wq	peer_wq;
 	wait_queue_entry_t	peer_wake;
 	struct scm_stat		scm_stat;
@@ -75,6 +92,24 @@ struct unix_sock {
 };
 
 #define unix_sk(ptr) container_of_const(ptr, struct unix_sock, sk)
+#define unix_peer(sk) (unix_sk(sk)->peer)
+
+#define unix_state_lock(s)	spin_lock(&unix_sk(s)->lock)
+#define unix_state_unlock(s)	spin_unlock(&unix_sk(s)->lock)
+enum unix_socket_lock_class {
+	U_LOCK_NORMAL,
+	U_LOCK_SECOND,	/* for double locking, see unix_state_double_lock(). */
+	U_LOCK_DIAG, /* used while dumping icons, see sk_diag_dump_icons(). */
+	U_LOCK_GC_LISTENER, /* used for listening socket while determining gc
+			     * candidates to close a small race window.
+			     */
+};
+
+static inline void unix_state_lock_nested(struct sock *sk,
+				   enum unix_socket_lock_class subclass)
+{
+	spin_lock_nested(&unix_sk(sk)->lock, subclass);
+}
 
 #define peer_wait peer_wq.wait