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/mm/readahead.c b/mm/readahead.c
index 517c0be7ce66..e83fe1c6e5ac 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -646,7 +646,7 @@ ssize_t ksys_readahead(int fd, loff_t offset, size_t count)
 
 	ret = -EBADF;
 	f = fdget(fd);
-	if (!f.file || !(f.file->f_mode & FMODE_READ))
+	if (!fd_file(f) || !(fd_file(f)->f_mode & FMODE_READ))
 		goto out;
 
 	/*
@@ -655,12 +655,12 @@ ssize_t ksys_readahead(int fd, loff_t offset, size_t count)
 	 * on this file, then we must return -EINVAL.
 	 */
 	ret = -EINVAL;
-	if (!f.file->f_mapping || !f.file->f_mapping->a_ops ||
-	    (!S_ISREG(file_inode(f.file)->i_mode) &&
-	    !S_ISBLK(file_inode(f.file)->i_mode)))
+	if (!fd_file(f)->f_mapping || !fd_file(f)->f_mapping->a_ops ||
+	    (!S_ISREG(file_inode(fd_file(f))->i_mode) &&
+	    !S_ISBLK(file_inode(fd_file(f))->i_mode)))
 		goto out;
 
-	ret = vfs_fadvise(f.file, offset, count, POSIX_FADV_WILLNEED);
+	ret = vfs_fadvise(fd_file(f), offset, count, POSIX_FADV_WILLNEED);
 out:
 	fdput(f);
 	return ret;