linux/fs/ubifs/ioctl.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * This file is part of UBIFS.
   4 *
   5 * Copyright (C) 2006-2008 Nokia Corporation.
   6 * Copyright (C) 2006, 2007 University of Szeged, Hungary
   7 *
   8 * Authors: Zoltan Sogor
   9 *          Artem Bityutskiy (Битюцкий Артём)
  10 *          Adrian Hunter
  11 */
  12
  13/* This file implements EXT2-compatible extended attribute ioctl() calls */
  14
  15#include <linux/compat.h>
  16#include <linux/mount.h>
  17#include "ubifs.h"
  18
  19/* Need to be kept consistent with checked flags in ioctl2ubifs() */
  20#define UBIFS_SUPPORTED_IOCTL_FLAGS \
  21        (FS_COMPR_FL | FS_SYNC_FL | FS_APPEND_FL | \
  22         FS_IMMUTABLE_FL | FS_DIRSYNC_FL)
  23
  24/**
  25 * ubifs_set_inode_flags - set VFS inode flags.
  26 * @inode: VFS inode to set flags for
  27 *
  28 * This function propagates flags from UBIFS inode object to VFS inode object.
  29 */
  30void ubifs_set_inode_flags(struct inode *inode)
  31{
  32        unsigned int flags = ubifs_inode(inode)->flags;
  33
  34        inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC |
  35                            S_ENCRYPTED);
  36        if (flags & UBIFS_SYNC_FL)
  37                inode->i_flags |= S_SYNC;
  38        if (flags & UBIFS_APPEND_FL)
  39                inode->i_flags |= S_APPEND;
  40        if (flags & UBIFS_IMMUTABLE_FL)
  41                inode->i_flags |= S_IMMUTABLE;
  42        if (flags & UBIFS_DIRSYNC_FL)
  43                inode->i_flags |= S_DIRSYNC;
  44        if (flags & UBIFS_CRYPT_FL)
  45                inode->i_flags |= S_ENCRYPTED;
  46}
  47
  48/*
  49 * ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
  50 * @ioctl_flags: flags to convert
  51 *
  52 * This function converts ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
  53 * (@UBIFS_COMPR_FL, etc).
  54 */
  55static int ioctl2ubifs(int ioctl_flags)
  56{
  57        int ubifs_flags = 0;
  58
  59        if (ioctl_flags & FS_COMPR_FL)
  60                ubifs_flags |= UBIFS_COMPR_FL;
  61        if (ioctl_flags & FS_SYNC_FL)
  62                ubifs_flags |= UBIFS_SYNC_FL;
  63        if (ioctl_flags & FS_APPEND_FL)
  64                ubifs_flags |= UBIFS_APPEND_FL;
  65        if (ioctl_flags & FS_IMMUTABLE_FL)
  66                ubifs_flags |= UBIFS_IMMUTABLE_FL;
  67        if (ioctl_flags & FS_DIRSYNC_FL)
  68                ubifs_flags |= UBIFS_DIRSYNC_FL;
  69
  70        return ubifs_flags;
  71}
  72
  73/*
  74 * ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
  75 * @ubifs_flags: flags to convert
  76 *
  77 * This function converts UBIFS inode flags (@UBIFS_COMPR_FL, etc) to ioctl
  78 * flags (@FS_COMPR_FL, etc).
  79 */
  80static int ubifs2ioctl(int ubifs_flags)
  81{
  82        int ioctl_flags = 0;
  83
  84        if (ubifs_flags & UBIFS_COMPR_FL)
  85                ioctl_flags |= FS_COMPR_FL;
  86        if (ubifs_flags & UBIFS_SYNC_FL)
  87                ioctl_flags |= FS_SYNC_FL;
  88        if (ubifs_flags & UBIFS_APPEND_FL)
  89                ioctl_flags |= FS_APPEND_FL;
  90        if (ubifs_flags & UBIFS_IMMUTABLE_FL)
  91                ioctl_flags |= FS_IMMUTABLE_FL;
  92        if (ubifs_flags & UBIFS_DIRSYNC_FL)
  93                ioctl_flags |= FS_DIRSYNC_FL;
  94
  95        return ioctl_flags;
  96}
  97
  98static int setflags(struct inode *inode, int flags)
  99{
 100        int oldflags, err, release;
 101        struct ubifs_inode *ui = ubifs_inode(inode);
 102        struct ubifs_info *c = inode->i_sb->s_fs_info;
 103        struct ubifs_budget_req req = { .dirtied_ino = 1,
 104                                        .dirtied_ino_d = ui->data_len };
 105
 106        err = ubifs_budget_space(c, &req);
 107        if (err)
 108                return err;
 109
 110        mutex_lock(&ui->ui_mutex);
 111        oldflags = ubifs2ioctl(ui->flags);
 112        err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
 113        if (err)
 114                goto out_unlock;
 115
 116        ui->flags = ioctl2ubifs(flags);
 117        ubifs_set_inode_flags(inode);
 118        inode->i_ctime = current_time(inode);
 119        release = ui->dirty;
 120        mark_inode_dirty_sync(inode);
 121        mutex_unlock(&ui->ui_mutex);
 122
 123        if (release)
 124                ubifs_release_budget(c, &req);
 125        if (IS_SYNC(inode))
 126                err = write_inode_now(inode, 1);
 127        return err;
 128
 129out_unlock:
 130        ubifs_err(c, "can't modify inode %lu attributes", inode->i_ino);
 131        mutex_unlock(&ui->ui_mutex);
 132        ubifs_release_budget(c, &req);
 133        return err;
 134}
 135
 136long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 137{
 138        int flags, err;
 139        struct inode *inode = file_inode(file);
 140
 141        switch (cmd) {
 142        case FS_IOC_GETFLAGS:
 143                flags = ubifs2ioctl(ubifs_inode(inode)->flags);
 144
 145                dbg_gen("get flags: %#x, i_flags %#x", flags, inode->i_flags);
 146                return put_user(flags, (int __user *) arg);
 147
 148        case FS_IOC_SETFLAGS: {
 149                if (IS_RDONLY(inode))
 150                        return -EROFS;
 151
 152                if (!inode_owner_or_capable(inode))
 153                        return -EACCES;
 154
 155                if (get_user(flags, (int __user *) arg))
 156                        return -EFAULT;
 157
 158                if (flags & ~UBIFS_SUPPORTED_IOCTL_FLAGS)
 159                        return -EOPNOTSUPP;
 160
 161                if (!S_ISDIR(inode->i_mode))
 162                        flags &= ~FS_DIRSYNC_FL;
 163
 164                /*
 165                 * Make sure the file-system is read-write and make sure it
 166                 * will not become read-only while we are changing the flags.
 167                 */
 168                err = mnt_want_write_file(file);
 169                if (err)
 170                        return err;
 171                dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
 172                err = setflags(inode, flags);
 173                mnt_drop_write_file(file);
 174                return err;
 175        }
 176        case FS_IOC_SET_ENCRYPTION_POLICY: {
 177                struct ubifs_info *c = inode->i_sb->s_fs_info;
 178
 179                err = ubifs_enable_encryption(c);
 180                if (err)
 181                        return err;
 182
 183                return fscrypt_ioctl_set_policy(file, (const void __user *)arg);
 184        }
 185        case FS_IOC_GET_ENCRYPTION_POLICY:
 186                return fscrypt_ioctl_get_policy(file, (void __user *)arg);
 187
 188        default:
 189                return -ENOTTY;
 190        }
 191}
 192
 193#ifdef CONFIG_COMPAT
 194long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 195{
 196        switch (cmd) {
 197        case FS_IOC32_GETFLAGS:
 198                cmd = FS_IOC_GETFLAGS;
 199                break;
 200        case FS_IOC32_SETFLAGS:
 201                cmd = FS_IOC_SETFLAGS;
 202                break;
 203        case FS_IOC_SET_ENCRYPTION_POLICY:
 204        case FS_IOC_GET_ENCRYPTION_POLICY:
 205                break;
 206        default:
 207                return -ENOIOCTLCMD;
 208        }
 209        return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 210}
 211#endif
 212