net: split out functions related to registering inflight socket files

We need this functionality for the io_uring file registration, but
we cannot rely on it since CONFIG_UNIX can be modular. Move the helpers
to a separate file, that's always builtin to the kernel if CONFIG_UNIX is
m/y.

No functional changes in this patch, just moving code around.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 2 insertions, 69 deletions

diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index f81854d74c7d..8bbe1b8e4ff7 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -86,80 +86,13 @@
 #include <net/scm.h>
 #include <net/tcp_states.h>
 
+#include "scm.h"
+
 /* Internal data structures and random procedures: */
 
-static LIST_HEAD(gc_inflight_list);
 static LIST_HEAD(gc_candidates);
-static DEFINE_SPINLOCK(unix_gc_lock);
 static DECLARE_WAIT_QUEUE_HEAD(unix_gc_wait);
 
-unsigned int unix_tot_inflight;
-
-struct sock *unix_get_socket(struct file *filp)
-{
-        struct sock *u_sock = NULL;
-        struct inode *inode = file_inode(filp);
-
-        /* Socket ? */
-        if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) {
-                struct socket *sock = SOCKET_I(inode);
-                struct sock *s = sock->sk;
-
-                /* PF_UNIX ? */
-                if (s && sock->ops && sock->ops->family == PF_UNIX)
-                        u_sock = s;
-        } else {
-                /* Could be an io_uring instance */
-                u_sock = io_uring_get_socket(filp);
-        }
-        return u_sock;
-}
-
-/* Keep the number of times in flight count for the file
- * descriptor if it is for an AF_UNIX socket.
- */
-
-void unix_inflight(struct user_struct *user, struct file *fp)
-{
-        struct sock *s = unix_get_socket(fp);
-
-        spin_lock(&unix_gc_lock);
-
-        if (s) {
-                struct unix_sock *u = unix_sk(s);
-
-                if (atomic_long_inc_return(&u->inflight) == 1) {
-                        BUG_ON(!list_empty(&u->link));
-                        list_add_tail(&u->link, &gc_inflight_list);
-                } else {
-                        BUG_ON(list_empty(&u->link));
-                }
-                unix_tot_inflight++;
-        }
-        user->unix_inflight++;
-        spin_unlock(&unix_gc_lock);
-}
-
-void unix_notinflight(struct user_struct *user, struct file *fp)
-{
-        struct sock *s = unix_get_socket(fp);
-
-        spin_lock(&unix_gc_lock);
-
-        if (s) {
-                struct unix_sock *u = unix_sk(s);
-
-                BUG_ON(!atomic_long_read(&u->inflight));
-                BUG_ON(list_empty(&u->link));
-
-                if (atomic_long_dec_and_test(&u->inflight))
-                        list_del_init(&u->link);
-                unix_tot_inflight--;
-        }
-        user->unix_inflight--;
-        spin_unlock(&unix_gc_lock);
-}
-
 static void scan_inflight(struct sock *x, void (*func)(struct unix_sock *),
                           struct sk_buff_head *hitlist)
 {