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, 2 insertions, 2 deletions

diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
index c429c42a6867..9ff37ae650ea 100644
--- a/fs/kernel_read_file.c
+++ b/fs/kernel_read_file.c
@@ -178,10 +178,10 @@ ssize_t kernel_read_file_from_fd(int fd, loff_t offset, void **buf,
 	struct fd f = fdget(fd);
 	ssize_t ret = -EBADF;
 
-	if (!f.file || !(f.file->f_mode & FMODE_READ))
+	if (!fd_file(f) || !(fd_file(f)->f_mode & FMODE_READ))
 		goto out;
 
-	ret = kernel_read_file(f.file, offset, buf, buf_size, file_size, id);
+	ret = kernel_read_file(fd_file(f), offset, buf, buf_size, file_size, id);
 out:
 	fdput(f);
 	return ret;