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