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>

1 files changed, 5 insertions, 5 deletions

diff --git a/kernel/pid.c b/kernel/pid.c
index da76ed1873f7..2715afb77eab 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -540,13 +540,13 @@ struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags)
 	struct pid *pid;
 
 	f = fdget(fd);
-	if (!f.file)
+	if (!fd_file(f))
 		return ERR_PTR(-EBADF);
 
-	pid = pidfd_pid(f.file);
+	pid = pidfd_pid(fd_file(f));
 	if (!IS_ERR(pid)) {
 		get_pid(pid);
-		*flags = f.file->f_flags;
+		*flags = fd_file(f)->f_flags;
 	}
 
 	fdput(f);
@@ -755,10 +755,10 @@ SYSCALL_DEFINE3(pidfd_getfd, int, pidfd, int, fd,
 		return -EINVAL;
 
 	f = fdget(pidfd);
-	if (!f.file)
+	if (!fd_file(f))
 		return -EBADF;
 
-	pid = pidfd_pid(f.file);
+	pid = pidfd_pid(fd_file(f));
 	if (IS_ERR(pid))
 		ret = PTR_ERR(pid);
 	else