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 <linux/fs.h>
  11 #include <linux/ext2_fs.h>
  12 #include <linux/sched.h>
  13 #include <asm/uaccess.h>
  14
  15
  16 int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  17                 unsigned long arg)
  18 {
  19         unsigned int flags;
  20
  21         ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  22
  23         switch (cmd) {
  24         case EXT2_IOC_GETFLAGS:
  25                 flags = inode->u.ext2_i.i_flags & EXT2_FL_USER_VISIBLE;
  26                 return put_user(flags, (int *) arg);
  27         case EXT2_IOC_SETFLAGS: {
  28                 unsigned int oldflags;
  29
  30                 if (IS_RDONLY(inode))
  31                         return -EROFS;
  32
  33                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  34                         return -EPERM;
  35
  36                 if (get_user(flags, (int *) arg))
  37                         return -EFAULT;
  38
  39                 oldflags = inode->u.ext2_i.i_flags;
  40
  41                 /*
  42                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  43                  * the relevant capability.
  44                  *
  45                  * This test looks nicer. Thanks to Pauline Middelink
  46                  */
  47                 if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
  48                         if (!capable(CAP_LINUX_IMMUTABLE))
  49                                 return -EPERM;
  50                 }
  51
  52                 flags = flags & EXT2_FL_USER_MODIFIABLE;
  53                 flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  54                 inode->u.ext2_i.i_flags = flags;
  55
  56                 if (flags & EXT2_SYNC_FL)
  57                         inode->i_flags |= S_SYNC;
  58                 else
  59                         inode->i_flags &= ~S_SYNC;
  60                 if (flags & EXT2_APPEND_FL)
  61                         inode->i_flags |= S_APPEND;
  62                 else
  63                         inode->i_flags &= ~S_APPEND;
  64                 if (flags & EXT2_IMMUTABLE_FL)
  65                         inode->i_flags |= S_IMMUTABLE;
  66                 else
  67                         inode->i_flags &= ~S_IMMUTABLE;
  68                 if (flags & EXT2_NOATIME_FL)
  69                         inode->i_flags |= S_NOATIME;
  70                 else
  71                         inode->i_flags &= ~S_NOATIME;
  72                 inode->i_ctime = CURRENT_TIME;
  73                 mark_inode_dirty(inode);
  74                 return 0;
  75         }
  76         case EXT2_IOC_GETVERSION:
  77                 return put_user(inode->i_generation, (int *) arg);
  78         case EXT2_IOC_SETVERSION:
  79                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  80                         return -EPERM;
  81                 if (IS_RDONLY(inode))
  82                         return -EROFS;
  83                 if (get_user(inode->i_generation, (int *) arg))
  84                         return -EFAULT;
  85                 inode->i_ctime = CURRENT_TIME;
  86                 mark_inode_dirty(inode);
  87                 return 0;
  88         default:
  89                 return -ENOTTY;
  90         }
  91 }