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 <asm/uaccess.h>
  11
  12 #include <linux/errno.h>
  13 #include <linux/fs.h>
  14 #include <linux/ext2_fs.h>
  15 #include <linux/ioctl.h>
  16 #include <linux/sched.h>
  17 #include <linux/mm.h>
  18
  19 int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  20                 unsigned long arg)
  21 {
  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 = inode->u.ext2_i.i_flags & EXT2_FL_USER_VISIBLE;
  29                 return put_user(inode->u.ext2_i.i_flags, (int *) arg);
  30         case EXT2_IOC_SETFLAGS:
  31                 if (get_user(flags, (int *) arg))
  32                         return -EFAULT;
  33                 flags = flags & EXT2_FL_USER_MODIFIABLE;
  34                 /*
  35                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  36                  * the super user when the security level is zero.
  37                  */
  38                 if ((flags & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) ^
  39                     (inode->u.ext2_i.i_flags &
  40                      (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL))) {
  41                         /* This test looks nicer. Thanks to Pauline Middelink */
  42                         if (!capable(CAP_LINUX_IMMUTABLE))
  43                                 return -EPERM;
  44                 } else
  45                         if ((current->fsuid != inode->i_uid) &&
  46                             !capable(CAP_FOWNER))
  47                                 return -EPERM;
  48                 if (IS_RDONLY(inode))
  49                         return -EROFS;
  50                 inode->u.ext2_i.i_flags = (inode->u.ext2_i.i_flags &
  51                                            ~EXT2_FL_USER_MODIFIABLE) | flags;
  52                 if (flags & EXT2_SYNC_FL)
  53                         inode->i_flags |= MS_SYNCHRONOUS;
  54                 else
  55                         inode->i_flags &= ~MS_SYNCHRONOUS;
  56                 if (flags & EXT2_APPEND_FL)
  57                         inode->i_flags |= S_APPEND;
  58                 else
  59                         inode->i_flags &= ~S_APPEND;
  60                 if (flags & EXT2_IMMUTABLE_FL)
  61                         inode->i_flags |= S_IMMUTABLE;
  62                 else
  63                         inode->i_flags &= ~S_IMMUTABLE;
  64                 if (flags & EXT2_NOATIME_FL)
  65                         inode->i_flags |= MS_NOATIME;
  66                 else
  67                         inode->i_flags &= ~MS_NOATIME;
  68                 inode->i_ctime = CURRENT_TIME;
  69                 mark_inode_dirty(inode);
  70                 return 0;
  71         case EXT2_IOC_GETVERSION:
  72                 return put_user(inode->i_generation, (int *) arg);
  73         case EXT2_IOC_SETVERSION:
  74                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  75                         return -EPERM;
  76                 if (IS_RDONLY(inode))
  77                         return -EROFS;
  78                 if (get_user(inode->i_generation, (int *) arg))
  79                         return -EFAULT;
  80                 inode->i_ctime = CURRENT_TIME;
  81                 mark_inode_dirty(inode);
  82                 return 0;
  83         default:
  84                 return -ENOTTY;
  85         }
  86 }