fs/hfsplus/ioctl.c

   1 /*
   2  *  linux/fs/hfsplus/ioctl.c
   3  *
   4  * Copyright (C) 2003
   5  * Ethan Benson <erbenson@alaska.net>
   6  * partially derived from linux/fs/ext2/ioctl.c
   7  * Copyright (C) 1993, 1994, 1995
   8  * Remy Card (card@masi.ibp.fr)
   9  * Laboratoire MASI - Institut Blaise Pascal
  10  * Universite Pierre et Marie Curie (Paris VI)
  11  *
  12  * hfsplus ioctls
  13  */
  14
  15 #include <linux/capability.h>
  16 #include <linux/fs.h>
  17 #include <linux/mount.h>
  18 #include <linux/sched.h>
  19 #include <linux/uaccess.h>
  20 #include "hfsplus_fs.h"
  21
  22 /*
  23  * "Blessing" an HFS+ filesystem writes metadata to the superblock informing
  24  * the platform firmware which file to boot from
  25  */
  26 static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
  27 {
  28         struct dentry *dentry = file->f_path.dentry;
  29         struct inode *inode = d_inode(dentry);
  30         struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
  31         struct hfsplus_vh *vh = sbi->s_vhdr;
  32         struct hfsplus_vh *bvh = sbi->s_backup_vhdr;
  33         u32 cnid = (unsigned long)dentry->d_fsdata;
  34
  35         if (!capable(CAP_SYS_ADMIN))
  36                 return -EPERM;
  37
  38         mutex_lock(&sbi->vh_mutex);
  39
  40         /* Directory containing the bootable system */
  41         vh->finder_info[0] = bvh->finder_info[0] =
  42                 cpu_to_be32(parent_ino(dentry));
  43
  44         /*
  45          * Bootloader. Just using the inode here breaks in the case of
  46          * hard links - the firmware wants the ID of the hard link file,
  47          * but the inode points at the indirect inode
  48          */
  49         vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid);
  50
  51         /* Per spec, the OS X system folder - same as finder_info[0] here */
  52         vh->finder_info[5] = bvh->finder_info[5] =
  53                 cpu_to_be32(parent_ino(dentry));
  54
  55         mutex_unlock(&sbi->vh_mutex);
  56         return 0;
  57 }
  58
  59 static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
  60 {
  61         struct inode *inode = file_inode(file);
  62         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
  63         unsigned int flags = 0;
  64
  65         if (inode->i_flags & S_IMMUTABLE)
  66                 flags |= FS_IMMUTABLE_FL;
  67         if (inode->i_flags & S_APPEND)
  68                 flags |= FS_APPEND_FL;
  69         if (hip->userflags & HFSPLUS_FLG_NODUMP)
  70                 flags |= FS_NODUMP_FL;
  71
  72         return put_user(flags, user_flags);
  73 }
  74
  75 static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
  76 {
  77         struct inode *inode = file_inode(file);
  78         struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
  79         unsigned int flags, new_fl = 0;
  80         int err = 0;
  81
  82         err = mnt_want_write_file(file);
  83         if (err)
  84                 goto out;
  85
  86         if (!inode_owner_or_capable(inode)) {
  87                 err = -EACCES;
  88                 goto out_drop_write;
  89         }
  90
  91         if (get_user(flags, user_flags)) {
  92                 err = -EFAULT;
  93                 goto out_drop_write;
  94         }
  95
  96         inode_lock(inode);
  97
  98         if ((flags & (FS_IMMUTABLE_FL|FS_APPEND_FL)) ||
  99             inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
 100                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 101                         err = -EPERM;
 102                         goto out_unlock_inode;
 103                 }
 104         }
 105
 106         /* don't silently ignore unsupported ext2 flags */
 107         if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
 108                 err = -EOPNOTSUPP;
 109                 goto out_unlock_inode;
 110         }
 111
 112         if (flags & FS_IMMUTABLE_FL)
 113                 new_fl |= S_IMMUTABLE;
 114
 115         if (flags & FS_APPEND_FL)
 116                 new_fl |= S_APPEND;
 117
 118         inode_set_flags(inode, new_fl, S_IMMUTABLE | S_APPEND);
 119
 120         if (flags & FS_NODUMP_FL)
 121                 hip->userflags |= HFSPLUS_FLG_NODUMP;
 122         else
 123                 hip->userflags &= ~HFSPLUS_FLG_NODUMP;
 124
 125         inode->i_ctime = current_time(inode);
 126         mark_inode_dirty(inode);
 127
 128 out_unlock_inode:
 129         inode_unlock(inode);
 130 out_drop_write:
 131         mnt_drop_write_file(file);
 132 out:
 133         return err;
 134 }
 135
 136 long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 137 {
 138         void __user *argp = (void __user *)arg;
 139
 140         switch (cmd) {
 141         case HFSPLUS_IOC_EXT2_GETFLAGS:
 142                 return hfsplus_ioctl_getflags(file, argp);
 143         case HFSPLUS_IOC_EXT2_SETFLAGS:
 144                 return hfsplus_ioctl_setflags(file, argp);
 145         case HFSPLUS_IOC_BLESS:
 146                 return hfsplus_ioctl_bless(file, argp);
 147         default:
 148                 return -ENOTTY;
 149         }
 150 }