https://github.com/torvalds/linux
Tip revision: 856deb866d16e29bd65952e0289066f6078af773 authored by Linus Torvalds on 13 September 2020, 23:06:00 UTC
Linux 5.9-rc5
Linux 5.9-rc5
Tip revision: 856deb8
ioctl.c
// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/hfsplus/ioctl.c
*
* Copyright (C) 2003
* Ethan Benson <erbenson@alaska.net>
* partially derived from linux/fs/ext2/ioctl.c
* Copyright (C) 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* hfsplus ioctls
*/
#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include "hfsplus_fs.h"
/*
* "Blessing" an HFS+ filesystem writes metadata to the superblock informing
* the platform firmware which file to boot from
*/
static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
{
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = d_inode(dentry);
struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
struct hfsplus_vh *vh = sbi->s_vhdr;
struct hfsplus_vh *bvh = sbi->s_backup_vhdr;
u32 cnid = (unsigned long)dentry->d_fsdata;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
mutex_lock(&sbi->vh_mutex);
/* Directory containing the bootable system */
vh->finder_info[0] = bvh->finder_info[0] =
cpu_to_be32(parent_ino(dentry));
/*
* Bootloader. Just using the inode here breaks in the case of
* hard links - the firmware wants the ID of the hard link file,
* but the inode points at the indirect inode
*/
vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid);
/* Per spec, the OS X system folder - same as finder_info[0] here */
vh->finder_info[5] = bvh->finder_info[5] =
cpu_to_be32(parent_ino(dentry));
mutex_unlock(&sbi->vh_mutex);
return 0;
}
static inline unsigned int hfsplus_getflags(struct inode *inode)
{
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
unsigned int flags = 0;
if (inode->i_flags & S_IMMUTABLE)
flags |= FS_IMMUTABLE_FL;
if (inode->i_flags & S_APPEND)
flags |= FS_APPEND_FL;
if (hip->userflags & HFSPLUS_FLG_NODUMP)
flags |= FS_NODUMP_FL;
return flags;
}
static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
{
struct inode *inode = file_inode(file);
unsigned int flags = hfsplus_getflags(inode);
return put_user(flags, user_flags);
}
static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
{
struct inode *inode = file_inode(file);
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
unsigned int flags, new_fl = 0;
unsigned int oldflags = hfsplus_getflags(inode);
int err = 0;
err = mnt_want_write_file(file);
if (err)
goto out;
if (!inode_owner_or_capable(inode)) {
err = -EACCES;
goto out_drop_write;
}
if (get_user(flags, user_flags)) {
err = -EFAULT;
goto out_drop_write;
}
inode_lock(inode);
err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (err)
goto out_unlock_inode;
/* don't silently ignore unsupported ext2 flags */
if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
err = -EOPNOTSUPP;
goto out_unlock_inode;
}
if (flags & FS_IMMUTABLE_FL)
new_fl |= S_IMMUTABLE;
if (flags & FS_APPEND_FL)
new_fl |= S_APPEND;
inode_set_flags(inode, new_fl, S_IMMUTABLE | S_APPEND);
if (flags & FS_NODUMP_FL)
hip->userflags |= HFSPLUS_FLG_NODUMP;
else
hip->userflags &= ~HFSPLUS_FLG_NODUMP;
inode->i_ctime = current_time(inode);
mark_inode_dirty(inode);
out_unlock_inode:
inode_unlock(inode);
out_drop_write:
mnt_drop_write_file(file);
out:
return err;
}
long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
switch (cmd) {
case HFSPLUS_IOC_EXT2_GETFLAGS:
return hfsplus_ioctl_getflags(file, argp);
case HFSPLUS_IOC_EXT2_SETFLAGS:
return hfsplus_ioctl_setflags(file, argp);
case HFSPLUS_IOC_BLESS:
return hfsplus_ioctl_bless(file, argp);
default:
return -ENOTTY;
}
}