1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/hfsplus/ioctl.c 4 * 5 * Copyright (C) 2003 6 * Ethan Benson <erbenson@alaska.net> 7 * partially derived from linux/fs/ext2/ioctl.c 8 * Copyright (C) 1993, 1994, 1995 9 * Remy Card (card@masi.ibp.fr) 10 * Laboratoire MASI - Institut Blaise Pascal 11 * Universite Pierre et Marie Curie (Paris VI) 12 * 13 * hfsplus ioctls 14 */ 15 16 #include <linux/capability.h> 17 #include <linux/fs.h> 18 #include <linux/mount.h> 19 #include <linux/sched.h> 20 #include <linux/uaccess.h> 21 #include "hfsplus_fs.h" 22 23 /* 24 * "Blessing" an HFS+ filesystem writes metadata to the superblock informing 25 * the platform firmware which file to boot from 26 */ 27 static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags) 28 { 29 struct dentry *dentry = file->f_path.dentry; 30 struct inode *inode = d_inode(dentry); 31 struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb); 32 struct hfsplus_vh *vh = sbi->s_vhdr; 33 struct hfsplus_vh *bvh = sbi->s_backup_vhdr; 34 u32 cnid = (unsigned long)dentry->d_fsdata; 35 36 if (!capable(CAP_SYS_ADMIN)) 37 return -EPERM; 38 39 mutex_lock(&sbi->vh_mutex); 40 41 /* Directory containing the bootable system */ 42 vh->finder_info[0] = bvh->finder_info[0] = 43 cpu_to_be32(parent_ino(dentry)); 44 45 /* 46 * Bootloader. Just using the inode here breaks in the case of 47 * hard links - the firmware wants the ID of the hard link file, 48 * but the inode points at the indirect inode 49 */ 50 vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid); 51 52 /* Per spec, the OS X system folder - same as finder_info[0] here */ 53 vh->finder_info[5] = bvh->finder_info[5] = 54 cpu_to_be32(parent_ino(dentry)); 55 56 mutex_unlock(&sbi->vh_mutex); 57 return 0; 58 } 59 60 static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags) 61 { 62 struct inode *inode = file_inode(file); 63 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 64 unsigned int flags = 0; 65 66 if (inode->i_flags & S_IMMUTABLE) 67 flags |= FS_IMMUTABLE_FL; 68 if (inode->i_flags & S_APPEND) 69 flags |= FS_APPEND_FL; 70 if (hip->userflags & HFSPLUS_FLG_NODUMP) 71 flags |= FS_NODUMP_FL; 72 73 return put_user(flags, user_flags); 74 } 75 76 static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags) 77 { 78 struct inode *inode = file_inode(file); 79 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 80 unsigned int flags, new_fl = 0; 81 int err = 0; 82 83 err = mnt_want_write_file(file); 84 if (err) 85 goto out; 86 87 if (!inode_owner_or_capable(inode)) { 88 err = -EACCES; 89 goto out_drop_write; 90 } 91 92 if (get_user(flags, user_flags)) { 93 err = -EFAULT; 94 goto out_drop_write; 95 } 96 97 inode_lock(inode); 98 99 if ((flags & (FS_IMMUTABLE_FL|FS_APPEND_FL)) || 100 inode->i_flags & (S_IMMUTABLE|S_APPEND)) { 101 if (!capable(CAP_LINUX_IMMUTABLE)) { 102 err = -EPERM; 103 goto out_unlock_inode; 104 } 105 } 106 107 /* don't silently ignore unsupported ext2 flags */ 108 if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) { 109 err = -EOPNOTSUPP; 110 goto out_unlock_inode; 111 } 112 113 if (flags & FS_IMMUTABLE_FL) 114 new_fl |= S_IMMUTABLE; 115 116 if (flags & FS_APPEND_FL) 117 new_fl |= S_APPEND; 118 119 inode_set_flags(inode, new_fl, S_IMMUTABLE | S_APPEND); 120 121 if (flags & FS_NODUMP_FL) 122 hip->userflags |= HFSPLUS_FLG_NODUMP; 123 else 124 hip->userflags &= ~HFSPLUS_FLG_NODUMP; 125 126 inode->i_ctime = current_time(inode); 127 mark_inode_dirty(inode); 128 129 out_unlock_inode: 130 inode_unlock(inode); 131 out_drop_write: 132 mnt_drop_write_file(file); 133 out: 134 return err; 135 } 136 137 long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 138 { 139 void __user *argp = (void __user *)arg; 140 141 switch (cmd) { 142 case HFSPLUS_IOC_EXT2_GETFLAGS: 143 return hfsplus_ioctl_getflags(file, argp); 144 case HFSPLUS_IOC_EXT2_SETFLAGS: 145 return hfsplus_ioctl_setflags(file, argp); 146 case HFSPLUS_IOC_BLESS: 147 return hfsplus_ioctl_bless(file, argp); 148 default: 149 return -ENOTTY; 150 } 151 } 152