LXR linux/fs/ext2/ioctl.c

   1/*
   2 * linux/fs/ext2/ioctl.c
   3 *
   4 * Copyright (C) 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 */
   9
  10#include "ext2.h"
  11#include <linux/capability.h>
  12#include <linux/time.h>
  13#include <linux/sched.h>
  14#include <linux/compat.h>
  15#include <linux/smp_lock.h>
  16#include <asm/current.h>
  17#include <asm/uaccess.h>
  18
  19
  20int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  21                unsigned long arg)
  22{
  23        struct ext2_inode_info *ei = EXT2_I(inode);
  24        unsigned int flags;
  25        unsigned short rsv_window_size;
  26
  27        ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  28
  29        switch (cmd) {
  30        case EXT2_IOC_GETFLAGS:
  31                ext2_get_inode_flags(ei);
  32                flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
  33                return put_user(flags, (int __user *) arg);
  34        case EXT2_IOC_SETFLAGS: {
  35                unsigned int oldflags;
  36
  37                if (IS_RDONLY(inode))
  38                        return -EROFS;
  39
  40                if (!is_owner_or_cap(inode))
  41                        return -EACCES;
  42
  43                if (get_user(flags, (int __user *) arg))
  44                        return -EFAULT;
  45
  46                if (!S_ISDIR(inode->i_mode))
  47                        flags &= ~EXT2_DIRSYNC_FL;
  48
  49                mutex_lock(&inode->i_mutex);
  50                /* Is it quota file? Do not allow user to mess with it */
  51                if (IS_NOQUOTA(inode)) {
  52                        mutex_unlock(&inode->i_mutex);
  53                        return -EPERM;
  54                }
  55                oldflags = ei->i_flags;
  56
  57                /*
  58                 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  59                 * the relevant capability.
  60                 *
  61                 * This test looks nicer. Thanks to Pauline Middelink
  62                 */
  63                if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
  64                        if (!capable(CAP_LINUX_IMMUTABLE)) {
  65                                mutex_unlock(&inode->i_mutex);
  66                                return -EPERM;
  67                        }
  68                }
  69
  70                flags = flags & EXT2_FL_USER_MODIFIABLE;
  71                flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  72                ei->i_flags = flags;
  73                mutex_unlock(&inode->i_mutex);
  74
  75                ext2_set_inode_flags(inode);
  76                inode->i_ctime = CURRENT_TIME_SEC;
  77                mark_inode_dirty(inode);
  78                return 0;
  79        }
  80        case EXT2_IOC_GETVERSION:
  81                return put_user(inode->i_generation, (int __user *) arg);
  82        case EXT2_IOC_SETVERSION:
  83                if (!is_owner_or_cap(inode))
  84                        return -EPERM;
  85                if (IS_RDONLY(inode))
  86                        return -EROFS;
  87                if (get_user(inode->i_generation, (int __user *) arg))
  88                        return -EFAULT; 
  89                inode->i_ctime = CURRENT_TIME_SEC;
  90                mark_inode_dirty(inode);
  91                return 0;
  92        case EXT2_IOC_GETRSVSZ:
  93                if (test_opt(inode->i_sb, RESERVATION)
  94                        && S_ISREG(inode->i_mode)
  95                        && ei->i_block_alloc_info) {
  96                        rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
  97                        return put_user(rsv_window_size, (int __user *)arg);
  98                }
  99                return -ENOTTY;
 100        case EXT2_IOC_SETRSVSZ: {
 101
 102                if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 103                        return -ENOTTY;
 104
 105                if (IS_RDONLY(inode))
 106                        return -EROFS;
 107
 108                if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 109                        return -EACCES;
 110
 111                if (get_user(rsv_window_size, (int __user *)arg))
 112                        return -EFAULT;
 113
 114                if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
 115                        rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
 116
 117                /*
 118                 * need to allocate reservation structure for this inode
 119                 * before set the window size
 120                 */
 121                /*
 122                 * XXX What lock should protect the rsv_goal_size?
 123                 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
 124                 */
 125                mutex_lock(&ei->truncate_mutex);
 126                if (!ei->i_block_alloc_info)
 127                        ext2_init_block_alloc_info(inode);
 128
 129                if (ei->i_block_alloc_info){
 130                        struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 131                        rsv->rsv_goal_size = rsv_window_size;
 132                }
 133                mutex_unlock(&ei->truncate_mutex);
 134                return 0;
 135        }
 136        default:
 137                return -ENOTTY;
 138        }
 139}
 140
 141#ifdef CONFIG_COMPAT
 142long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 143{
 144        struct inode *inode = file->f_path.dentry->d_inode;
 145        int ret;
 146
 147        /* These are just misnamed, they actually get/put from/to user an int */
 148        switch (cmd) {
 149        case EXT2_IOC32_GETFLAGS:
 150                cmd = EXT2_IOC_GETFLAGS;
 151                break;
 152        case EXT2_IOC32_SETFLAGS:
 153                cmd = EXT2_IOC_SETFLAGS;
 154                break;
 155        case EXT2_IOC32_GETVERSION:
 156                cmd = EXT2_IOC_GETVERSION;
 157                break;
 158        case EXT2_IOC32_SETVERSION:
 159                cmd = EXT2_IOC_SETVERSION;
 160                break;
 161        default:
 162                return -ENOIOCTLCMD;
 163        }
 164        lock_kernel();
 165        ret = ext2_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 166        unlock_kernel();
 167        return ret;
 168}
 169#endif
 170