LXR linux/fs/ext2/ioctl.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * linux/fs/ext2/ioctl.c
   4 *
   5 * Copyright (C) 1993, 1994, 1995
   6 * Remy Card (card@masi.ibp.fr)
   7 * Laboratoire MASI - Institut Blaise Pascal
   8 * Universite Pierre et Marie Curie (Paris VI)
   9 */
  10
  11#include "ext2.h"
  12#include <linux/capability.h>
  13#include <linux/time.h>
  14#include <linux/sched.h>
  15#include <linux/compat.h>
  16#include <linux/mount.h>
  17#include <asm/current.h>
  18#include <linux/uaccess.h>
  19#include <linux/fileattr.h>
  20
  21int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
  22{
  23        struct ext2_inode_info *ei = EXT2_I(d_inode(dentry));
  24
  25        fileattr_fill_flags(fa, ei->i_flags & EXT2_FL_USER_VISIBLE);
  26
  27        return 0;
  28}
  29
  30int ext2_fileattr_set(struct user_namespace *mnt_userns,
  31                      struct dentry *dentry, struct fileattr *fa)
  32{
  33        struct inode *inode = d_inode(dentry);
  34        struct ext2_inode_info *ei = EXT2_I(inode);
  35
  36        if (fileattr_has_fsx(fa))
  37                return -EOPNOTSUPP;
  38
  39        /* Is it quota file? Do not allow user to mess with it */
  40        if (IS_NOQUOTA(inode))
  41                return -EPERM;
  42
  43        ei->i_flags = (ei->i_flags & ~EXT2_FL_USER_MODIFIABLE) |
  44                (fa->flags & EXT2_FL_USER_MODIFIABLE);
  45
  46        ext2_set_inode_flags(inode);
  47        inode->i_ctime = current_time(inode);
  48        mark_inode_dirty(inode);
  49
  50        return 0;
  51}
  52
  53
  54long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  55{
  56        struct inode *inode = file_inode(filp);
  57        struct ext2_inode_info *ei = EXT2_I(inode);
  58        unsigned short rsv_window_size;
  59        int ret;
  60
  61        ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  62
  63        switch (cmd) {
  64        case EXT2_IOC_GETVERSION:
  65                return put_user(inode->i_generation, (int __user *) arg);
  66        case EXT2_IOC_SETVERSION: {
  67                __u32 generation;
  68
  69                if (!inode_owner_or_capable(&init_user_ns, inode))
  70                        return -EPERM;
  71                ret = mnt_want_write_file(filp);
  72                if (ret)
  73                        return ret;
  74                if (get_user(generation, (int __user *) arg)) {
  75                        ret = -EFAULT;
  76                        goto setversion_out;
  77                }
  78
  79                inode_lock(inode);
  80                inode->i_ctime = current_time(inode);
  81                inode->i_generation = generation;
  82                inode_unlock(inode);
  83
  84                mark_inode_dirty(inode);
  85setversion_out:
  86                mnt_drop_write_file(filp);
  87                return ret;
  88        }
  89        case EXT2_IOC_GETRSVSZ:
  90                if (test_opt(inode->i_sb, RESERVATION)
  91                        && S_ISREG(inode->i_mode)
  92                        && ei->i_block_alloc_info) {
  93                        rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
  94                        return put_user(rsv_window_size, (int __user *)arg);
  95                }
  96                return -ENOTTY;
  97        case EXT2_IOC_SETRSVSZ: {
  98
  99                if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 100                        return -ENOTTY;
 101
 102                if (!inode_owner_or_capable(&init_user_ns, inode))
 103                        return -EACCES;
 104
 105                if (get_user(rsv_window_size, (int __user *)arg))
 106                        return -EFAULT;
 107
 108                ret = mnt_want_write_file(filp);
 109                if (ret)
 110                        return ret;
 111
 112                if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
 113                        rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
 114
 115                /*
 116                 * need to allocate reservation structure for this inode
 117                 * before set the window size
 118                 */
 119                /*
 120                 * XXX What lock should protect the rsv_goal_size?
 121                 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
 122                 */
 123                mutex_lock(&ei->truncate_mutex);
 124                if (!ei->i_block_alloc_info)
 125                        ext2_init_block_alloc_info(inode);
 126
 127                if (ei->i_block_alloc_info){
 128                        struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 129                        rsv->rsv_goal_size = rsv_window_size;
 130                } else {
 131                        ret = -ENOMEM;
 132                }
 133
 134                mutex_unlock(&ei->truncate_mutex);
 135                mnt_drop_write_file(filp);
 136                return ret;
 137        }
 138        default:
 139                return -ENOTTY;
 140        }
 141}
 142
 143#ifdef CONFIG_COMPAT
 144long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 145{
 146        /* These are just misnamed, they actually get/put from/to user an int */
 147        switch (cmd) {
 148        case EXT2_IOC32_GETVERSION:
 149                cmd = EXT2_IOC_GETVERSION;
 150                break;
 151        case EXT2_IOC32_SETVERSION:
 152                cmd = EXT2_IOC_SETVERSION;
 153                break;
 154        default:
 155                return -ENOIOCTLCMD;
 156        }
 157        return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 158}
 159#endif
 160