fs/ext3/ioctl.c

   1 /*
   2  * linux/fs/ext3/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/jbd.h>
  12 #include <linux/ext3_fs.h>
  13 #include <linux/ext3_jbd.h>
  14 #include <linux/time.h>
  15 #include <linux/vserver/xid.h>
  16 #include <asm/uaccess.h>
  17
  18
  19 int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  20                 unsigned long arg)
  21 {
  22         struct ext3_inode_info *ei = EXT3_I(inode);
  23         unsigned int flags;
  24         unsigned short rsv_window_size;
  25
  26         ext3_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  27
  28         switch (cmd) {
  29         case EXT3_IOC_GETFLAGS:
  30                 flags = ei->i_flags & EXT3_FL_USER_VISIBLE;
  31                 return put_user(flags, (int __user *) arg);
  32         case EXT3_IOC_SETFLAGS: {
  33                 handle_t *handle = NULL;
  34                 int err;
  35                 struct ext3_iloc iloc;
  36                 unsigned int oldflags;
  37                 unsigned int jflag;
  38
  39                 if (IS_RDONLY(inode) ||
  40                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
  41                         return -EROFS;
  42
  43                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  44                         return -EACCES;
  45
  46                 if (get_user(flags, (int __user *) arg))
  47                         return -EFAULT;
  48
  49                 if (!S_ISDIR(inode->i_mode))
  50                         flags &= ~EXT3_DIRSYNC_FL;
  51
  52                 oldflags = ei->i_flags;
  53
  54                 /* The JOURNAL_DATA flag is modifiable only by root */
  55                 jflag = flags & EXT3_JOURNAL_DATA_FL;
  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 ((oldflags & EXT3_IMMUTABLE_FL) ||
  64                         ((flags ^ oldflags) & (EXT3_APPEND_FL |
  65                         EXT3_IMMUTABLE_FL | EXT3_IUNLINK_FL))) {
  66                         if (!capable(CAP_LINUX_IMMUTABLE))
  67                                 return -EPERM;
  68                 }
  69
  70                 /*
  71                  * The JOURNAL_DATA flag can only be changed by
  72                  * the relevant capability.
  73                  */
  74                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
  75                         if (!capable(CAP_SYS_RESOURCE))
  76                                 return -EPERM;
  77                 }
  78
  79
  80                 handle = ext3_journal_start(inode, 1);
  81                 if (IS_ERR(handle))
  82                         return PTR_ERR(handle);
  83                 if (IS_SYNC(inode))
  84                         handle->h_sync = 1;
  85                 err = ext3_reserve_inode_write(handle, inode, &iloc);
  86                 if (err)
  87                         goto flags_err;
  88
  89                 flags = flags & EXT3_FL_USER_MODIFIABLE;
  90                 flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
  91                 ei->i_flags = flags;
  92
  93                 ext3_set_inode_flags(inode);
  94                 inode->i_ctime = CURRENT_TIME_SEC;
  95
  96                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
  97 flags_err:
  98                 ext3_journal_stop(handle);
  99                 if (err)
 100                         return err;
 101
 102                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
 103                         err = ext3_change_inode_journal_flag(inode, jflag);
 104                 return err;
 105         }
 106         case EXT3_IOC_GETVERSION:
 107         case EXT3_IOC_GETVERSION_OLD:
 108                 return put_user(inode->i_generation, (int __user *) arg);
 109         case EXT3_IOC_SETVERSION:
 110         case EXT3_IOC_SETVERSION_OLD: {
 111                 handle_t *handle;
 112                 struct ext3_iloc iloc;
 113                 __u32 generation;
 114                 int err;
 115
 116                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 117                         return -EPERM;
 118                 if (IS_RDONLY(inode) ||
 119                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 120                         return -EROFS;
 121                 if (get_user(generation, (int __user *) arg))
 122                         return -EFAULT;
 123
 124                 handle = ext3_journal_start(inode, 1);
 125                 if (IS_ERR(handle))
 126                         return PTR_ERR(handle);
 127                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 128                 if (err == 0) {
 129                         inode->i_ctime = CURRENT_TIME_SEC;
 130                         inode->i_generation = generation;
 131                         err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 132                 }
 133                 ext3_journal_stop(handle);
 134                 return err;
 135         }
 136 #ifdef CONFIG_JBD_DEBUG
 137         case EXT3_IOC_WAIT_FOR_READONLY:
 138                 /*
 139                  * This is racy - by the time we're woken up and running,
 140                  * the superblock could be released.  And the module could
 141                  * have been unloaded.  So sue me.
 142                  *
 143                  * Returns 1 if it slept, else zero.
 144                  */
 145                 {
 146                         struct super_block *sb = inode->i_sb;
 147                         DECLARE_WAITQUEUE(wait, current);
 148                         int ret = 0;
 149
 150                         set_current_state(TASK_INTERRUPTIBLE);
 151                         add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 152                         if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
 153                                 schedule();
 154                                 ret = 1;
 155                         }
 156                         remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 157                         return ret;
 158                 }
 159 #endif
 160         case EXT3_IOC_GETRSVSZ:
 161                 if (test_opt(inode->i_sb, RESERVATION)
 162                         && S_ISREG(inode->i_mode)
 163                         && ei->i_block_alloc_info) {
 164                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 165                         return put_user(rsv_window_size, (int __user *)arg);
 166                 }
 167                 return -ENOTTY;
 168         case EXT3_IOC_SETRSVSZ: {
 169
 170                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 171                         return -ENOTTY;
 172
 173                 if (IS_RDONLY(inode))
 174                         return -EROFS;
 175
 176                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 177                         return -EACCES;
 178
 179                 if (get_user(rsv_window_size, (int __user *)arg))
 180                         return -EFAULT;
 181
 182                 if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
 183                         rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
 184
 185                 /*
 186                  * need to allocate reservation structure for this inode
 187                  * before set the window size
 188                  */
 189                 down(&ei->truncate_sem);
 190                 if (!ei->i_block_alloc_info)
 191                         ext3_init_block_alloc_info(inode);
 192
 193                 if (ei->i_block_alloc_info){
 194                         struct ext3_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 195                         rsv->rsv_goal_size = rsv_window_size;
 196                 }
 197                 up(&ei->truncate_sem);
 198                 return 0;
 199         }
 200         case EXT3_IOC_GROUP_EXTEND: {
 201                 unsigned long n_blocks_count;
 202                 struct super_block *sb = inode->i_sb;
 203                 int err;
 204
 205                 if (!capable(CAP_SYS_RESOURCE))
 206                         return -EPERM;
 207
 208                 if (IS_RDONLY(inode))
 209                         return -EROFS;
 210
 211                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 212                         return -EFAULT;
 213
 214                 err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
 215                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 216                 journal_flush(EXT3_SB(sb)->s_journal);
 217                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 218
 219                 return err;
 220         }
 221         case EXT3_IOC_GROUP_ADD: {
 222                 struct ext3_new_group_data input;
 223                 struct super_block *sb = inode->i_sb;
 224                 int err;
 225
 226                 if (!capable(CAP_SYS_RESOURCE))
 227                         return -EPERM;
 228
 229                 if (IS_RDONLY(inode))
 230                         return -EROFS;
 231
 232                 if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
 233                                 sizeof(input)))
 234                         return -EFAULT;
 235
 236                 err = ext3_group_add(sb, &input);
 237                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 238                 journal_flush(EXT3_SB(sb)->s_journal);
 239                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 240
 241                 return err;
 242         }
 243
 244 #if defined(CONFIG_VSERVER_LEGACY) && !defined(CONFIG_INOXID_NONE)
 245         case EXT3_IOC_SETXID: {
 246                 handle_t *handle;
 247                 struct ext3_iloc iloc;
 248                 int xid;
 249                 int err;
 250
 251                 /* fixme: if stealth, return -ENOTTY */
 252                 if (!capable(CAP_CONTEXT))
 253                         return -EPERM;
 254                 if (IS_RDONLY(inode))
 255                         return -EROFS;
 256                 if (!(inode->i_sb->s_flags & MS_TAGXID))
 257                         return -ENOSYS;
 258                 if (get_user(xid, (int *) arg))
 259                         return -EFAULT;
 260
 261                 handle = ext3_journal_start(inode, 1);
 262                 if (IS_ERR(handle))
 263                         return PTR_ERR(handle);
 264                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 265                 if (err)
 266                         return err;
 267
 268                 inode->i_xid = (xid & 0xFFFF);
 269                 inode->i_ctime = CURRENT_TIME;
 270
 271                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 272                 ext3_journal_stop(handle);
 273                 return err;
 274         }
 275 #endif
 276
 277         default:
 278                 return -ENOTTY;
 279         }
 280 }