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                 ext2_get_inode_flags(ei);
  31                 flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
  32                 return put_user(flags, (int __user *) arg);
  33         case EXT2_IOC_SETFLAGS: {
  34                 unsigned int oldflags;
  35
  36                 if (IS_RDONLY(inode))
  37                         return -EROFS;
  38
  39                 if (!is_owner_or_cap(inode))
  40                         return -EACCES;
  41
  42                 if (get_user(flags, (int __user *) arg))
  43                         return -EFAULT;
  44
  45                 if (!S_ISDIR(inode->i_mode))
  46                         flags &= ~EXT2_DIRSYNC_FL;
  47
  48                 mutex_lock(&inode->i_mutex);
  49                 oldflags = ei->i_flags;
  50
  51                 /*
  52                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  53                  * the relevant capability.
  54                  *
  55                  * This test looks nicer. Thanks to Pauline Middelink
  56                  */
  57                 if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
  58                         if (!capable(CAP_LINUX_IMMUTABLE)) {
  59                                 mutex_unlock(&inode->i_mutex);
  60                                 return -EPERM;
  61                         }
  62                 }
  63
  64                 flags = flags & EXT2_FL_USER_MODIFIABLE;
  65                 flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  66                 ei->i_flags = flags;
  67                 mutex_unlock(&inode->i_mutex);
  68
  69                 ext2_set_inode_flags(inode);
  70                 inode->i_ctime = CURRENT_TIME_SEC;
  71                 mark_inode_dirty(inode);
  72                 return 0;
  73         }
  74         case EXT2_IOC_GETVERSION:
  75                 return put_user(inode->i_generation, (int __user *) arg);
  76         case EXT2_IOC_SETVERSION:
  77                 if (!is_owner_or_cap(inode))
  78                         return -EPERM;
  79                 if (IS_RDONLY(inode))
  80                         return -EROFS;
  81                 if (get_user(inode->i_generation, (int __user *) arg))
  82                         return -EFAULT;
  83                 inode->i_ctime = CURRENT_TIME_SEC;
  84                 mark_inode_dirty(inode);
  85                 return 0;
  86         default:
  87                 return -ENOTTY;
  88         }
  89 }
  90
  91 #ifdef CONFIG_COMPAT
  92 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  93 {
  94         struct inode *inode = file->f_path.dentry->d_inode;
  95         int ret;
  96
  97         /* These are just misnamed, they actually get/put from/to user an int */
  98         switch (cmd) {
  99         case EXT2_IOC32_GETFLAGS:
 100                 cmd = EXT2_IOC_GETFLAGS;
 101                 break;
 102         case EXT2_IOC32_SETFLAGS:
 103                 cmd = EXT2_IOC_SETFLAGS;
 104                 break;
 105         case EXT2_IOC32_GETVERSION:
 106                 cmd = EXT2_IOC_GETVERSION;
 107                 break;
 108         case EXT2_IOC32_SETVERSION:
 109                 cmd = EXT2_IOC_SETVERSION;
 110                 break;
 111         default:
 112                 return -ENOIOCTLCMD;
 113         }
 114         lock_kernel();
 115         ret = ext2_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 116         unlock_kernel();
 117         return ret;
 118 }
 119 #endif