introduce fd_file(), convert all accessors to it.

	For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
	Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
	This commit converts (almost) all of f.file to
fd_file(f).  It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).

	NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).

[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]

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

2 files changed, 9 insertions, 9 deletions

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 6a823ba906c6..18b7c8f31234 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -711,11 +711,11 @@ struct net *get_net_ns_by_fd(int fd)
 	struct fd f = fdget(fd);
 	struct net *net = ERR_PTR(-EINVAL);
 
-	if (!f.file)
+	if (!fd_file(f))
 		return ERR_PTR(-EBADF);
 
-	if (proc_ns_file(f.file)) {
-		struct ns_common *ns = get_proc_ns(file_inode(f.file));
+	if (proc_ns_file(fd_file(f))) {
+		struct ns_common *ns = get_proc_ns(file_inode(fd_file(f)));
 		if (ns->ops == &netns_operations)
 			net = get_net(container_of(ns, struct net, ns));
 	}
diff --git a/net/socket.c b/net/socket.c
index fcbdd5bc47ac..f77a42a74510 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -556,8 +556,8 @@ static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
 	struct socket *sock;
 
 	*err = -EBADF;
-	if (f.file) {
-		sock = sock_from_file(f.file);
+	if (fd_file(f)) {
+		sock = sock_from_file(fd_file(f));
 		if (likely(sock)) {
 			*fput_needed = f.flags & FDPUT_FPUT;
 			return sock;
@@ -2008,8 +2008,8 @@ int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr,
 	struct fd f;
 
 	f = fdget(fd);
-	if (f.file) {
-		ret = __sys_accept4_file(f.file, upeer_sockaddr,
+	if (fd_file(f)) {
+		ret = __sys_accept4_file(fd_file(f), upeer_sockaddr,
 					 upeer_addrlen, flags);
 		fdput(f);
 	}
@@ -2070,12 +2070,12 @@ int __sys_connect(int fd, struct sockaddr __user *uservaddr, int addrlen)
 	struct fd f;
 
 	f = fdget(fd);
-	if (f.file) {
+	if (fd_file(f)) {
 		struct sockaddr_storage address;
 
 		ret = move_addr_to_kernel(uservaddr, addrlen, &address);
 		if (!ret)
-			ret = __sys_connect_file(f.file, &address, addrlen, 0);
+			ret = __sys_connect_file(fd_file(f), &address, addrlen, 0);
 		fdput(f);
 	}