Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull 'struct fd' class updates from Al Viro:
 "The bulk of struct fd memory safety stuff

  Making sure that struct fd instances are destroyed in the same scope
  where they'd been created, getting rid of reassignments and passing
  them by reference, converting to CLASS(fd{,_pos,_raw}).

  We are getting very close to having the memory safety of that stuff
  trivial to verify"

* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  deal with the last remaing boolean uses of fd_file()
  css_set_fork(): switch to CLASS(fd_raw, ...)
  memcg_write_event_control(): switch to CLASS(fd)
  assorted variants of irqfd setup: convert to CLASS(fd)
  do_pollfd(): convert to CLASS(fd)
  convert do_select()
  convert vfs_dedupe_file_range().
  convert cifs_ioctl_copychunk()
  convert media_request_get_by_fd()
  convert spu_run(2)
  switch spufs_calls_{get,put}() to CLASS() use
  convert cachestat(2)
  convert do_preadv()/do_pwritev()
  fdget(), more trivial conversions
  fdget(), trivial conversions
  privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
  o2hb_region_dev_store(): avoid goto around fdget()/fdput()
  introduce "fd_pos" class, convert fdget_pos() users to it.
  fdget_raw() users: switch to CLASS(fd_raw)
  convert vmsplice() to CLASS(fd)
  ...

3 files changed, 33 insertions, 70 deletions

diff --git a/fs/xfs/xfs_exchrange.c b/fs/xfs/xfs_exchrange.c
index 75cb53f090d1..fa29c8b334d2 100644
--- a/fs/xfs/xfs_exchrange.c
+++ b/fs/xfs/xfs_exchrange.c
@@ -813,8 +813,6 @@ xfs_ioc_exchange_range(
 		.file2			= file,
 	};
 	struct xfs_exchange_range	args;
-	struct fd			file1;
-	int				error;
 
 	if (copy_from_user(&args, argp, sizeof(args)))
 		return -EFAULT;
@@ -828,14 +826,12 @@ xfs_ioc_exchange_range(
 	fxr.length		= args.length;
 	fxr.flags		= args.flags;
 
-	file1 = fdget(args.file1_fd);
-	if (!fd_file(file1))
+	CLASS(fd, file1)(args.file1_fd);
+	if (fd_empty(file1))
 		return -EBADF;
 	fxr.file1 = fd_file(file1);
 
-	error = xfs_exchange_range(&fxr);
-	fdput(file1);
-	return error;
+	return xfs_exchange_range(&fxr);
 }
 
 /* Opaque freshness blob for XFS_IOC_COMMIT_RANGE */
@@ -909,8 +905,6 @@ xfs_ioc_commit_range(
 	struct xfs_commit_range_fresh	*kern_f;
 	struct xfs_inode		*ip2 = XFS_I(file_inode(file));
 	struct xfs_mount		*mp = ip2->i_mount;
-	struct fd			file1;
-	int				error;
 
 	kern_f = (struct xfs_commit_range_fresh *)&args.file2_freshness;
 
@@ -934,12 +928,10 @@ xfs_ioc_commit_range(
 	fxr.file2_ctime.tv_sec	= kern_f->file2_ctime;
 	fxr.file2_ctime.tv_nsec	= kern_f->file2_ctime_nsec;
 
-	file1 = fdget(args.file1_fd);
+	CLASS(fd, file1)(args.file1_fd);
 	if (fd_empty(file1))
 		return -EBADF;
 	fxr.file1 = fd_file(file1);
 
-	error = xfs_exchange_range(&fxr);
-	fdput(file1);
-	return error;
+	return xfs_exchange_range(&fxr);
 }
diff --git a/fs/xfs/xfs_handle.c b/fs/xfs/xfs_handle.c
index 49e5e5f04e60..f19fce557354 100644
--- a/fs/xfs/xfs_handle.c
+++ b/fs/xfs/xfs_handle.c
@@ -85,22 +85,23 @@ xfs_find_handle(
 	int			hsize;
 	xfs_handle_t		handle;
 	struct inode		*inode;
-	struct fd		f = EMPTY_FD;
 	struct path		path;
 	int			error;
 	struct xfs_inode	*ip;
 
 	if (cmd == XFS_IOC_FD_TO_HANDLE) {
-		f = fdget(hreq->fd);
-		if (!fd_file(f))
+		CLASS(fd, f)(hreq->fd);
+
+		if (fd_empty(f))
 			return -EBADF;
-		inode = file_inode(fd_file(f));
+		path = fd_file(f)->f_path;
+		path_get(&path);
 	} else {
 		error = user_path_at(AT_FDCWD, hreq->path, 0, &path);
 		if (error)
 			return error;
-		inode = d_inode(path.dentry);
 	}
+	inode = d_inode(path.dentry);
 	ip = XFS_I(inode);
 
 	/*
@@ -134,10 +135,7 @@ xfs_find_handle(
 	error = 0;
 
  out_put:
-	if (cmd == XFS_IOC_FD_TO_HANDLE)
-		fdput(f);
-	else
-		path_put(&path);
+	path_put(&path);
 	return error;
 }
 
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 2567fd2a0994..af1bb5db1c59 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -881,41 +881,29 @@ xfs_ioc_swapext(
 	xfs_swapext_t	*sxp)
 {
 	xfs_inode_t     *ip, *tip;
-	struct fd	f, tmp;
-	int		error = 0;
 
 	/* Pull information for the target fd */
-	f = fdget((int)sxp->sx_fdtarget);
-	if (!fd_file(f)) {
-		error = -EINVAL;
-		goto out;
-	}
+	CLASS(fd, f)((int)sxp->sx_fdtarget);
+	if (fd_empty(f))
+		return -EINVAL;
 
 	if (!(fd_file(f)->f_mode & FMODE_WRITE) ||
 	    !(fd_file(f)->f_mode & FMODE_READ) ||
-	    (fd_file(f)->f_flags & O_APPEND)) {
-		error = -EBADF;
-		goto out_put_file;
-	}
+	    (fd_file(f)->f_flags & O_APPEND))
+		return -EBADF;
 
-	tmp = fdget((int)sxp->sx_fdtmp);
-	if (!fd_file(tmp)) {
-		error = -EINVAL;
-		goto out_put_file;
-	}
+	CLASS(fd, tmp)((int)sxp->sx_fdtmp);
+	if (fd_empty(tmp))
+		return -EINVAL;
 
 	if (!(fd_file(tmp)->f_mode & FMODE_WRITE) ||
 	    !(fd_file(tmp)->f_mode & FMODE_READ) ||
-	    (fd_file(tmp)->f_flags & O_APPEND)) {
-		error = -EBADF;
-		goto out_put_tmp_file;
-	}
+	    (fd_file(tmp)->f_flags & O_APPEND))
+		return -EBADF;
 
 	if (IS_SWAPFILE(file_inode(fd_file(f))) ||
-	    IS_SWAPFILE(file_inode(fd_file(tmp)))) {
-		error = -EINVAL;
-		goto out_put_tmp_file;
-	}
+	    IS_SWAPFILE(file_inode(fd_file(tmp))))
+		return -EINVAL;
 
 	/*
 	 * We need to ensure that the fds passed in point to XFS inodes
@@ -923,37 +911,22 @@ xfs_ioc_swapext(
 	 * control over what the user passes us here.
 	 */
 	if (fd_file(f)->f_op != &xfs_file_operations ||
-	    fd_file(tmp)->f_op != &xfs_file_operations) {
-		error = -EINVAL;
-		goto out_put_tmp_file;
-	}
+	    fd_file(tmp)->f_op != &xfs_file_operations)
+		return -EINVAL;
 
 	ip = XFS_I(file_inode(fd_file(f)));
 	tip = XFS_I(file_inode(fd_file(tmp)));
 
-	if (ip->i_mount != tip->i_mount) {
-		error = -EINVAL;
-		goto out_put_tmp_file;
-	}
-
-	if (ip->i_ino == tip->i_ino) {
-		error = -EINVAL;
-		goto out_put_tmp_file;
-	}
+	if (ip->i_mount != tip->i_mount)
+		return -EINVAL;
 
-	if (xfs_is_shutdown(ip->i_mount)) {
-		error = -EIO;
-		goto out_put_tmp_file;
-	}
+	if (ip->i_ino == tip->i_ino)
+		return -EINVAL;
 
-	error = xfs_swap_extents(ip, tip, sxp);
+	if (xfs_is_shutdown(ip->i_mount))
+		return -EIO;
 
- out_put_tmp_file:
-	fdput(tmp);
- out_put_file:
-	fdput(f);
- out:
-	return error;
+	return xfs_swap_extents(ip, tip, sxp);
 }
 
 static int