[PATCH v4 29/47] net/sctp: convert sctp_getsockopt_peeloff_common() to FD_PREPARE()

[Christian Brauner <brauner@kernel.org>]

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 net/sctp/socket.c | 90 ++++++++++++++++---------------------------------------
 1 file changed, 25 insertions(+), 65 deletions(-)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index ed8293a34240..206f9b7e648e 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -5664,47 +5664,45 @@ static int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id,
 	return err;
 }
 
-static int sctp_getsockopt_peeloff_common(struct sock *sk, sctp_peeloff_arg_t *peeloff,
-					  struct file **newfile, unsigned flags)
+static int sctp_getsockopt_peeloff_common(struct sock *sk,
+					  sctp_peeloff_arg_t *peeloff, int len,
+					  char __user *optval,
+					  int __user *optlen, unsigned flags)
 {
 	struct socket *newsock;
 	int retval;
 
 	retval = sctp_do_peeloff(sk, peeloff->associd, &newsock);
 	if (retval < 0)
-		goto out;
+		return retval;
 
-	/* Map the socket to an unused fd that can be returned to the user.  */
-	retval = get_unused_fd_flags(flags & SOCK_CLOEXEC);
-	if (retval < 0) {
+	FD_PREPARE(fdf, flags & SOCK_CLOEXEC, sock_alloc_file(newsock, 0, NULL));
+	if (fdf.err) {
 		sock_release(newsock);
-		goto out;
-	}
-
-	*newfile = sock_alloc_file(newsock, 0, NULL);
-	if (IS_ERR(*newfile)) {
-		put_unused_fd(retval);
-		retval = PTR_ERR(*newfile);
-		*newfile = NULL;
-		return retval;
+		return fdf.err;
 	}
 
 	pr_debug("%s: sk:%p, newsk:%p, sd:%d\n", __func__, sk, newsock->sk,
-		 retval);
-
-	peeloff->sd = retval;
+		 fd_prepare_fd(fdf));
 
 	if (flags & SOCK_NONBLOCK)
-		(*newfile)->f_flags |= O_NONBLOCK;
-out:
-	return retval;
+		fd_prepare_file(fdf)->f_flags |= O_NONBLOCK;
+
+	/* Return the fd mapped to the new socket.  */
+	if (put_user(len, optlen))
+		return -EFAULT;
+
+	if (copy_to_user(optval, &peeloff, len))
+		return -EFAULT;
+
+	peeloff->sd = fd_prepare_fd(fdf);
+	return fd_publish(fdf);
 }
 
-static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval, int __user *optlen)
+static int sctp_getsockopt_peeloff(struct sock *sk, int len,
+				   char __user *optval, int __user *optlen)
 {
 	sctp_peeloff_arg_t peeloff;
-	struct file *newfile = NULL;
-	int retval = 0;
 
 	if (len < sizeof(sctp_peeloff_arg_t))
 		return -EINVAL;
@@ -5712,33 +5710,13 @@ static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval
 	if (copy_from_user(&peeloff, optval, len))
 		return -EFAULT;
 
-	retval = sctp_getsockopt_peeloff_common(sk, &peeloff, &newfile, 0);
-	if (retval < 0)
-		goto out;
-
-	/* Return the fd mapped to the new socket.  */
-	if (put_user(len, optlen)) {
-		fput(newfile);
-		put_unused_fd(retval);
-		return -EFAULT;
-	}
-
-	if (copy_to_user(optval, &peeloff, len)) {
-		fput(newfile);
-		put_unused_fd(retval);
-		return -EFAULT;
-	}
-	fd_install(retval, newfile);
-out:
-	return retval;
+	return sctp_getsockopt_peeloff_common(sk, &peeloff, len, optval, optlen, 0);
 }
 
 static int sctp_getsockopt_peeloff_flags(struct sock *sk, int len,
 					 char __user *optval, int __user *optlen)
 {
 	sctp_peeloff_flags_arg_t peeloff;
-	struct file *newfile = NULL;
-	int retval = 0;
 
 	if (len < sizeof(sctp_peeloff_flags_arg_t))
 		return -EINVAL;
@@ -5746,26 +5724,8 @@ static int sctp_getsockopt_peeloff_flags(struct sock *sk, int len,
 	if (copy_from_user(&peeloff, optval, len))
 		return -EFAULT;
 
-	retval = sctp_getsockopt_peeloff_common(sk, &peeloff.p_arg,
-						&newfile, peeloff.flags);
-	if (retval < 0)
-		goto out;
-
-	/* Return the fd mapped to the new socket.  */
-	if (put_user(len, optlen)) {
-		fput(newfile);
-		put_unused_fd(retval);
-		return -EFAULT;
-	}
-
-	if (copy_to_user(optval, &peeloff, len)) {
-		fput(newfile);
-		put_unused_fd(retval);
-		return -EFAULT;
-	}
-	fd_install(retval, newfile);
-out:
-	return retval;
+	return sctp_getsockopt_peeloff_common(sk, &peeloff.p_arg, len, optval,
+					      optlen, peeloff.flags);
 }
 
 /* 7.1.13 Peer Address Parameters (SCTP_PEER_ADDR_PARAMS)

-- 
2.47.3