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         unsigned short rsv_window_size;
  26
  27         ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  28
  29         switch (cmd) {
  30         case EXT2_IOC_GETFLAGS:
  31                 ext2_get_inode_flags(ei);
  32                 flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
  33                 return put_user(flags, (int __user *) arg);
  34         case EXT2_IOC_SETFLAGS: {
  35                 unsigned int oldflags;
  36
  37                 if (IS_RDONLY(inode))
  38                         return -EROFS;
  39
  40                 if (!is_owner_or_cap(inode))
  41                         return -EACCES;
  42
  43                 if (get_user(flags, (int __user *) arg))
  44                         return -EFAULT;
  45
  46                 if (!S_ISDIR(inode->i_mode))
  47                         flags &= ~EXT2_DIRSYNC_FL;
  48
  49                 mutex_lock(&inode->i_mutex);
  50                 /* Is it quota file? Do not allow user to mess with it */
  51                 if (IS_NOQUOTA(inode)) {
  52                         mutex_unlock(&inode->i_mutex);
  53                         return -EPERM;
  54                 }
  55                 oldflags = ei->i_flags;
  56
  57                 /*
  58                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  59                  * the relevant capability.
  60                  *
  61                  * This test looks nicer. Thanks to Pauline Middelink
  62                  */
  63                 if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
  64                         if (!capable(CAP_LINUX_IMMUTABLE)) {
  65                                 mutex_unlock(&inode->i_mutex);
  66                                 return -EPERM;
  67                         }
  68                 }
  69
  70                 flags = flags & EXT2_FL_USER_MODIFIABLE;
  71                 flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  72                 ei->i_flags = flags;
  73                 mutex_unlock(&inode->i_mutex);
  74
  75                 ext2_set_inode_flags(inode);
  76                 inode->i_ctime = CURRENT_TIME_SEC;
  77                 mark_inode_dirty(inode);
  78                 return 0;
  79         }
  80         case EXT2_IOC_GETVERSION:
  81                 return put_user(inode->i_generation, (int __user *) arg);
  82         case EXT2_IOC_SETVERSION:
  83                 if (!is_owner_or_cap(inode))
  84                         return -EPERM;
  85                 if (IS_RDONLY(inode))
  86                         return -EROFS;
  87                 if (get_user(inode->i_generation, (int __user *) arg))
  88                         return -EFAULT;
  89                 inode->i_ctime = CURRENT_TIME_SEC;
  90                 mark_inode_dirty(inode);
  91                 return 0;
  92         case EXT2_IOC_GETRSVSZ:
  93                 if (test_opt(inode->i_sb, RESERVATION)
  94                         && S_ISREG(inode->i_mode)
  95                         && ei->i_block_alloc_info) {
  96                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
  97                         return put_user(rsv_window_size, (int __user *)arg);
  98                 }
  99                 return -ENOTTY;
 100         case EXT2_IOC_SETRSVSZ: {
 101
 102                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 103                         return -ENOTTY;
 104
 105                 if (IS_RDONLY(inode))
 106                         return -EROFS;
 107
 108                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 109                         return -EACCES;
 110
 111                 if (get_user(rsv_window_size, (int __user *)arg))
 112                         return -EFAULT;
 113
 114                 if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
 115                         rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
 116
 117                 /*
 118                  * need to allocate reservation structure for this inode
 119                  * before set the window size
 120                  */
 121                 /*
 122                  * XXX What lock should protect the rsv_goal_size?
 123                  * Accessed in ext2_get_block only.  ext3 uses i_truncate.
 124                  */
 125                 mutex_lock(&ei->truncate_mutex);
 126                 if (!ei->i_block_alloc_info)
 127                         ext2_init_block_alloc_info(inode);
 128
 129                 if (ei->i_block_alloc_info){
 130                         struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 131                         rsv->rsv_goal_size = rsv_window_size;
 132                 }
 133                 mutex_unlock(&ei->truncate_mutex);
 134                 return 0;
 135         }
 136         default:
 137                 return -ENOTTY;
 138         }
 139 }
 140
 141 #ifdef CONFIG_COMPAT
 142 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 143 {
 144         struct inode *inode = file->f_path.dentry->d_inode;
 145         int ret;
 146
 147         /* These are just misnamed, they actually get/put from/to user an int */
 148         switch (cmd) {
 149         case EXT2_IOC32_GETFLAGS:
 150                 cmd = EXT2_IOC_GETFLAGS;
 151                 break;
 152         case EXT2_IOC32_SETFLAGS:
 153                 cmd = EXT2_IOC_SETFLAGS;
 154                 break;
 155         case EXT2_IOC32_GETVERSION:
 156                 cmd = EXT2_IOC_GETVERSION;
 157                 break;
 158         case EXT2_IOC32_SETVERSION:
 159                 cmd = EXT2_IOC_SETVERSION;
 160                 break;
 161         default:
 162                 return -ENOIOCTLCMD;
 163         }
 164         lock_kernel();
 165         ret = ext2_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 166         unlock_kernel();
 167         return ret;
 168 }
 169 #endif