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 inline unsigned int hfsplus_getflags(struct inode *inode) 61 { 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 return flags; 72 } 73 74 static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags) 75 { 76 struct inode *inode = file_inode(file); 77 unsigned int flags = hfsplus_getflags(inode); 78 79 return put_user(flags, user_flags); 80 } 81 82 static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags) 83 { 84 struct inode *inode = file_inode(file); 85 struct hfsplus_inode_info *hip = HFSPLUS_I(inode); 86 unsigned int flags, new_fl = 0; 87 unsigned int oldflags = hfsplus_getflags(inode); 88 int err = 0; 89 90 err = mnt_want_write_file(file); 91 if (err) 92 goto out; 93 94 if (!inode_owner_or_capable(&init_user_ns, inode)) { 95 err = -EACCES; 96 goto out_drop_write; 97 } 98 99 if (get_user(flags, user_flags)) { 100 err = -EFAULT; 101 goto out_drop_write; 102 } 103 104 inode_lock(inode); 105 106 err = vfs_ioc_setflags_prepare(inode, oldflags, flags); 107 if (err) 108 goto out_unlock_inode; 109 110 /* don't silently ignore unsupported ext2 flags */ 111 if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) { 112 err = -EOPNOTSUPP; 113 goto out_unlock_inode; 114 } 115 116 if (flags & FS_IMMUTABLE_FL) 117 new_fl |= S_IMMUTABLE; 118 119 if (flags & FS_APPEND_FL) 120 new_fl |= S_APPEND; 121 122 inode_set_flags(inode, new_fl, S_IMMUTABLE | S_APPEND); 123 124 if (flags & FS_NODUMP_FL) 125 hip->userflags |= HFSPLUS_FLG_NODUMP; 126 else 127 hip->userflags &= ~HFSPLUS_FLG_NODUMP; 128 129 inode->i_ctime = current_time(inode); 130 mark_inode_dirty(inode); 131 132 out_unlock_inode: 133 inode_unlock(inode); 134 out_drop_write: 135 mnt_drop_write_file(file); 136 out: 137 return err; 138 } 139 140 long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 141 { 142 void __user *argp = (void __user *)arg; 143 144 switch (cmd) { 145 case HFSPLUS_IOC_EXT2_GETFLAGS: 146 return hfsplus_ioctl_getflags(file, argp); 147 case HFSPLUS_IOC_EXT2_SETFLAGS: 148 return hfsplus_ioctl_setflags(file, argp); 149 case HFSPLUS_IOC_BLESS: 150 return hfsplus_ioctl_bless(file, argp); 151 default: 152 return -ENOTTY; 153 } 154 } 155