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
  20 int 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
  26         ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  27
  28         switch (cmd) {
  29         case EXT2_IOC_GETFLAGS:
  30                 flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
  31                 return put_user(flags, (int __user *) arg);
  32         case EXT2_IOC_SETFLAGS: {
  33                 unsigned int oldflags;
  34
  35                 if (IS_RDONLY(inode))
  36                         return -EROFS;
  37
  38                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  39                         return -EACCES;
  40
  41                 if (get_user(flags, (int __user *) arg))
  42                         return -EFAULT;
  43
  44                 if (!S_ISDIR(inode->i_mode))
  45                         flags &= ~EXT2_DIRSYNC_FL;
  46
  47                 mutex_lock(&inode->i_mutex);
  48                 oldflags = ei->i_flags;
  49
  50                 /*
  51                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  52                  * the relevant capability.
  53                  *
  54                  * This test looks nicer. Thanks to Pauline Middelink
  55                  */
  56                 if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
  57                         if (!capable(CAP_LINUX_IMMUTABLE)) {
  58                                 mutex_unlock(&inode->i_mutex);
  59                                 return -EPERM;
  60                         }
  61                 }
  62
  63                 flags = flags & EXT2_FL_USER_MODIFIABLE;
  64                 flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  65                 ei->i_flags = flags;
  66                 mutex_unlock(&inode->i_mutex);
  67
  68                 ext2_set_inode_flags(inode);
  69                 inode->i_ctime = CURRENT_TIME_SEC;
  70                 mark_inode_dirty(inode);
  71                 return 0;
  72         }
  73         case EXT2_IOC_GETVERSION:
  74                 return put_user(inode->i_generation, (int __user *) arg);
  75         case EXT2_IOC_SETVERSION:
  76                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  77                         return -EPERM;
  78                 if (IS_RDONLY(inode))
  79                         return -EROFS;
  80                 if (get_user(inode->i_generation, (int __user *) arg))
  81                         return -EFAULT;
  82                 inode->i_ctime = CURRENT_TIME_SEC;
  83                 mark_inode_dirty(inode);
  84                 return 0;
  85         default:
  86                 return -ENOTTY;
  87         }
  88 }
  89
  90 #ifdef CONFIG_COMPAT
  91 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  92 {
  93         struct inode *inode = file->f_path.dentry->d_inode;
  94         int ret;
  95
  96         /* These are just misnamed, they actually get/put from/to user an int */
  97         switch (cmd) {
  98         case EXT2_IOC32_GETFLAGS:
  99                 cmd = EXT2_IOC_GETFLAGS;
 100                 break;
 101         case EXT2_IOC32_SETFLAGS:
 102                 cmd = EXT2_IOC_SETFLAGS;
 103                 break;
 104         case EXT2_IOC32_GETVERSION:
 105                 cmd = EXT2_IOC_GETVERSION;
 106                 break;
 107         case EXT2_IOC32_SETVERSION:
 108                 cmd = EXT2_IOC_SETVERSION;
 109                 break;
 110         default:
 111                 return -ENOIOCTLCMD;
 112         }
 113         lock_kernel();
 114         ret = ext2_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 115         unlock_kernel();
 116         return ret;
 117 }
 118 #endif