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, 3 insertions, 3 deletions

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index e8bf5972dd47..1c77400bd88e 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -1343,10 +1343,10 @@ group_extend_out:
 		me.moved_len = 0;
 
 		donor = fdget(me.donor_fd);
-		if (!donor.file)
+		if (!fd_file(donor))
 			return -EBADF;
 
-		if (!(donor.file->f_mode & FMODE_WRITE)) {
+		if (!(fd_file(donor)->f_mode & FMODE_WRITE)) {
 			err = -EBADF;
 			goto mext_out;
 		}
@@ -1367,7 +1367,7 @@ group_extend_out:
 		if (err)
 			goto mext_out;
 
-		err = ext4_move_extents(filp, donor.file, me.orig_start,
+		err = ext4_move_extents(filp, fd_file(donor), me.orig_start,
 					me.donor_start, me.len, &me.moved_len);
 		mnt_drop_write_file(filp);