linux/fs/hfsplus/ioctl.c
Matthew Garrett 7dea9665fe hfsplus: fix bless ioctl when used with hardlinks
HFS+ doesn't really implement hard links - instead, hardlinks are indicated
by a magic file type which refers to an indirect node in a hidden
directory. The spec indicates that stat() should return the inode number
of the indirect node, but it turns out that this doesn't satisfy the
firmware when it's looking for a bootloader - it wants the catalog ID of
the hardlink file instead. Fix up this case.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-17 14:39:59 -07:00

260 lines
6.2 KiB
C

/*
* 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/xattr.h>
#include <asm/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 = dentry->d_inode;
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 int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
{
struct inode *inode = file->f_path.dentry->d_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 put_user(flags, user_flags);
}
static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
unsigned int flags;
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;
}
mutex_lock(&inode->i_mutex);
if ((flags & (FS_IMMUTABLE_FL|FS_APPEND_FL)) ||
inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
err = -EPERM;
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)
inode->i_flags |= S_IMMUTABLE;
else
inode->i_flags &= ~S_IMMUTABLE;
if (flags & FS_APPEND_FL)
inode->i_flags |= S_APPEND;
else
inode->i_flags &= ~S_APPEND;
if (flags & FS_NODUMP_FL)
hip->userflags |= HFSPLUS_FLG_NODUMP;
else
hip->userflags &= ~HFSPLUS_FLG_NODUMP;
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
out_unlock_inode:
mutex_unlock(&inode->i_mutex);
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;
}
}
int hfsplus_setxattr(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags)
{
struct inode *inode = dentry->d_inode;
struct hfs_find_data fd;
hfsplus_cat_entry entry;
struct hfsplus_cat_file *file;
int res;
if (!S_ISREG(inode->i_mode) || HFSPLUS_IS_RSRC(inode))
return -EOPNOTSUPP;
res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
if (res)
return res;
res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
if (res)
goto out;
hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
sizeof(struct hfsplus_cat_file));
file = &entry.file;
if (!strcmp(name, "hfs.type")) {
if (size == 4)
memcpy(&file->user_info.fdType, value, 4);
else
res = -ERANGE;
} else if (!strcmp(name, "hfs.creator")) {
if (size == 4)
memcpy(&file->user_info.fdCreator, value, 4);
else
res = -ERANGE;
} else
res = -EOPNOTSUPP;
if (!res) {
hfs_bnode_write(fd.bnode, &entry, fd.entryoffset,
sizeof(struct hfsplus_cat_file));
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
}
out:
hfs_find_exit(&fd);
return res;
}
ssize_t hfsplus_getxattr(struct dentry *dentry, const char *name,
void *value, size_t size)
{
struct inode *inode = dentry->d_inode;
struct hfs_find_data fd;
hfsplus_cat_entry entry;
struct hfsplus_cat_file *file;
ssize_t res = 0;
if (!S_ISREG(inode->i_mode) || HFSPLUS_IS_RSRC(inode))
return -EOPNOTSUPP;
if (size) {
res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
if (res)
return res;
res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
if (res)
goto out;
hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
sizeof(struct hfsplus_cat_file));
}
file = &entry.file;
if (!strcmp(name, "hfs.type")) {
if (size >= 4) {
memcpy(value, &file->user_info.fdType, 4);
res = 4;
} else
res = size ? -ERANGE : 4;
} else if (!strcmp(name, "hfs.creator")) {
if (size >= 4) {
memcpy(value, &file->user_info.fdCreator, 4);
res = 4;
} else
res = size ? -ERANGE : 4;
} else
res = -EOPNOTSUPP;
out:
if (size)
hfs_find_exit(&fd);
return res;
}
#define HFSPLUS_ATTRLIST_SIZE (sizeof("hfs.creator")+sizeof("hfs.type"))
ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
struct inode *inode = dentry->d_inode;
if (!S_ISREG(inode->i_mode) || HFSPLUS_IS_RSRC(inode))
return -EOPNOTSUPP;
if (!buffer || !size)
return HFSPLUS_ATTRLIST_SIZE;
if (size < HFSPLUS_ATTRLIST_SIZE)
return -ERANGE;
strcpy(buffer, "hfs.type");
strcpy(buffer + sizeof("hfs.type"), "hfs.creator");
return HFSPLUS_ATTRLIST_SIZE;
}