switch netlink_getsockbyfilp() to taking descriptor

the only call site (in do_mq_notify()) obtains the argument
from an immediately preceding fdget() and it is immediately
followed by fdput(); might as well just replace it with
a variant that would take a descriptor instead of struct file *
and have file lookups handled inside that function.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 7 insertions, 2 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 0b7a89db3ab7..42451ac355d0 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1180,11 +1180,16 @@ static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
 	return sock;
 }
 
-struct sock *netlink_getsockbyfilp(struct file *filp)
+struct sock *netlink_getsockbyfd(int fd)
 {
-	struct inode *inode = file_inode(filp);
+	CLASS(fd, f)(fd);
+	struct inode *inode;
 	struct sock *sock;
 
+	if (fd_empty(f))
+		return ERR_PTR(-EBADF);
+
+	inode = file_inode(fd_file(f));
 	if (!S_ISSOCK(inode->i_mode))
 		return ERR_PTR(-ENOTSOCK);