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 <asm/current.h>
  15 #include <asm/uaccess.h>
  16
  17
  18 int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  19                 unsigned long arg)
  20 {
  21         struct ext2_inode_info *ei = EXT2_I(inode);
  22         unsigned int flags;
  23
  24         ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  25
  26         switch (cmd) {
  27         case EXT2_IOC_GETFLAGS:
  28                 flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
  29                 return put_user(flags, (int __user *) arg);
  30         case EXT2_IOC_SETFLAGS: {
  31                 unsigned int oldflags;
  32
  33                 if (IS_RDONLY(inode))
  34                         return -EROFS;
  35
  36                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  37                         return -EACCES;
  38
  39                 if (get_user(flags, (int __user *) arg))
  40                         return -EFAULT;
  41
  42                 if (!S_ISDIR(inode->i_mode))
  43                         flags &= ~EXT2_DIRSYNC_FL;
  44
  45                 oldflags = ei->i_flags;
  46
  47                 /*
  48                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  49                  * the relevant capability.
  50                  *
  51                  * This test looks nicer. Thanks to Pauline Middelink
  52                  */
  53                 if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
  54                         if (!capable(CAP_LINUX_IMMUTABLE))
  55                                 return -EPERM;
  56                 }
  57
  58                 flags = flags & EXT2_FL_USER_MODIFIABLE;
  59                 flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  60                 ei->i_flags = flags;
  61
  62                 ext2_set_inode_flags(inode);
  63                 inode->i_ctime = CURRENT_TIME_SEC;
  64                 mark_inode_dirty(inode);
  65                 return 0;
  66         }
  67         case EXT2_IOC_GETVERSION:
  68                 return put_user(inode->i_generation, (int __user *) arg);
  69         case EXT2_IOC_SETVERSION:
  70                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  71                         return -EPERM;
  72                 if (IS_RDONLY(inode))
  73                         return -EROFS;
  74                 if (get_user(inode->i_generation, (int __user *) arg))
  75                         return -EFAULT;
  76                 inode->i_ctime = CURRENT_TIME_SEC;
  77                 mark_inode_dirty(inode);
  78                 return 0;
  79         default:
  80                 return -ENOTTY;
  81         }
  82 }