[PATCH v6.1 02/27] af_unix: Return struct unix_sock from unix_get_socket().

[Lee Jones <lee@kernel.org>]

From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit 5b17307bd0789edea0675d524a2b277b93bbde62 ]

Currently, unix_get_socket() returns struct sock, but after calling
it, we always cast it to unix_sk().

Let's return struct unix_sock from unix_get_socket().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240123170856.41348-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(cherry picked from commit 5b17307bd0789edea0675d524a2b277b93bbde62)
Signed-off-by: Lee Jones <lee@kernel.org>
---
 include/net/af_unix.h |  2 +-
 net/unix/garbage.c    | 19 +++++++------------
 net/unix/scm.c        | 19 +++++++------------
 3 files changed, 15 insertions(+), 25 deletions(-)

diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index e7d71a516bd4..52ae023c3e93 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -13,7 +13,7 @@ void unix_notinflight(struct user_struct *user, struct file *fp);
 void unix_destruct_scm(struct sk_buff *skb);
 void unix_gc(void);
 void wait_for_unix_gc(void);
-struct sock *unix_get_socket(struct file *filp);
+struct unix_sock *unix_get_socket(struct file *filp);
 struct sock *unix_peer_get(struct sock *sk);
 
 #define UNIX_HASH_MOD	(256 - 1)
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index d2fc795394a5..438f5d9b9173 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -105,20 +105,15 @@ static void scan_inflight(struct sock *x, void (*func)(struct unix_sock *),
 
 			while (nfd--) {
 				/* Get the socket the fd matches if it indeed does so */
-				struct sock *sk = unix_get_socket(*fp++);
+				struct unix_sock *u = unix_get_socket(*fp++);
 
-				if (sk) {
-					struct unix_sock *u = unix_sk(sk);
+				/* Ignore non-candidates, they could have been added
+				 * to the queues after starting the garbage collection
+				 */
+				if (u && test_bit(UNIX_GC_CANDIDATE, &u->gc_flags)) {
+					hit = true;
 
-					/* Ignore non-candidates, they could
-					 * have been added to the queues after
-					 * starting the garbage collection
-					 */
-					if (test_bit(UNIX_GC_CANDIDATE, &u->gc_flags)) {
-						hit = true;
-
-						func(u);
-					}
+					func(u);
 				}
 			}
 			if (hit && hitlist != NULL) {
diff --git a/net/unix/scm.c b/net/unix/scm.c
index 4eff7da9f6f9..693817a31ad8 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -21,9 +21,8 @@ EXPORT_SYMBOL(gc_inflight_list);
 DEFINE_SPINLOCK(unix_gc_lock);
 EXPORT_SYMBOL(unix_gc_lock);
 
-struct sock *unix_get_socket(struct file *filp)
+struct unix_sock *unix_get_socket(struct file *filp)
 {
-	struct sock *u_sock = NULL;
 	struct inode *inode = file_inode(filp);
 
 	/* Socket ? */
@@ -33,10 +32,10 @@ struct sock *unix_get_socket(struct file *filp)
 
 		/* PF_UNIX ? */
 		if (s && sock->ops && sock->ops->family == PF_UNIX)
-			u_sock = s;
+			return unix_sk(s);
 	}
 
-	return u_sock;
+	return NULL;
 }
 EXPORT_SYMBOL(unix_get_socket);
 
@@ -45,13 +44,11 @@ EXPORT_SYMBOL(unix_get_socket);
  */
 void unix_inflight(struct user_struct *user, struct file *fp)
 {
-	struct sock *s = unix_get_socket(fp);
+	struct unix_sock *u = unix_get_socket(fp);
 
 	spin_lock(&unix_gc_lock);
 
-	if (s) {
-		struct unix_sock *u = unix_sk(s);
-
+	if (u) {
 		if (!u->inflight) {
 			BUG_ON(!list_empty(&u->link));
 			list_add_tail(&u->link, &gc_inflight_list);
@@ -68,13 +65,11 @@ void unix_inflight(struct user_struct *user, struct file *fp)
 
 void unix_notinflight(struct user_struct *user, struct file *fp)
 {
-	struct sock *s = unix_get_socket(fp);
+	struct unix_sock *u = unix_get_socket(fp);
 
 	spin_lock(&unix_gc_lock);
 
-	if (s) {
-		struct unix_sock *u = unix_sk(s);
-
+	if (u) {
 		BUG_ON(!u->inflight);
 		BUG_ON(list_empty(&u->link));
 
-- 
2.49.0.1143.g0be31eac6b-goog