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                 oldflags = ei->i_flags;
  48
  49                 /*
  50                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  51                  * the relevant capability.
  52                  *
  53                  * This test looks nicer. Thanks to Pauline Middelink
  54                  */
  55                 if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
  56                         if (!capable(CAP_LINUX_IMMUTABLE))
  57                                 return -EPERM;
  58                 }
  59
  60                 flags = flags & EXT2_FL_USER_MODIFIABLE;
  61                 flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  62                 ei->i_flags = flags;
  63
  64                 ext2_set_inode_flags(inode);
  65                 inode->i_ctime = CURRENT_TIME_SEC;
  66                 mark_inode_dirty(inode);
  67                 return 0;
  68         }
  69         case EXT2_IOC_GETVERSION:
  70                 return put_user(inode->i_generation, (int __user *) arg);
  71         case EXT2_IOC_SETVERSION:
  72                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  73                         return -EPERM;
  74                 if (IS_RDONLY(inode))
  75                         return -EROFS;
  76                 if (get_user(inode->i_generation, (int __user *) arg))
  77                         return -EFAULT;
  78                 inode->i_ctime = CURRENT_TIME_SEC;
  79                 mark_inode_dirty(inode);
  80                 return 0;
  81         default:
  82                 return -ENOTTY;
  83         }
  84 }
  85
  86 #ifdef CONFIG_COMPAT
  87 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  88 {
  89         struct inode *inode = file->f_dentry->d_inode;
  90         int ret;
  91
  92         /* These are just misnamed, they actually get/put from/to user an int */
  93         switch (cmd) {
  94         case EXT2_IOC32_GETFLAGS:
  95                 cmd = EXT2_IOC_GETFLAGS;
  96                 break;
  97         case EXT2_IOC32_SETFLAGS:
  98                 cmd = EXT2_IOC_SETFLAGS;
  99                 break;
 100         case EXT2_IOC32_GETVERSION:
 101                 cmd = EXT2_IOC_GETVERSION;
 102                 break;
 103         case EXT2_IOC32_SETVERSION:
 104                 cmd = EXT2_IOC_SETVERSION;
 105                 break;
 106         default:
 107                 return -ENOIOCTLCMD;
 108         }
 109         lock_kernel();
 110         ret = ext2_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 111         unlock_kernel();
 112         return ret;
 113 }
 114 #endif