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                         return -EROFS;
  41
  42                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  43                         return -EACCES;
  44
  45                 if (get_user(flags, (int __user *) arg))
  46                         return -EFAULT;
  47
  48                 if (!S_ISDIR(inode->i_mode))
  49                         flags &= ~EXT3_DIRSYNC_FL;
  50
  51                 oldflags = ei->i_flags;
  52
  53                 /* The JOURNAL_DATA flag is modifiable only by root */
  54                 jflag = flags & EXT3_JOURNAL_DATA_FL;
  55
  56                 /*
  57                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  58                  * the relevant capability.
  59                  *
  60                  * This test looks nicer. Thanks to Pauline Middelink
  61                  */
  62                 if ((oldflags & EXT3_IMMUTABLE_FL) ||
  63                         ((flags ^ oldflags) & (EXT3_APPEND_FL |
  64                         EXT3_IMMUTABLE_FL | EXT3_IUNLINK_FL))) {
  65                         if (!capable(CAP_LINUX_IMMUTABLE))
  66                                 return -EPERM;
  67                 }
  68
  69                 /*
  70                  * The JOURNAL_DATA flag can only be changed by
  71                  * the relevant capability.
  72                  */
  73                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
  74                         if (!capable(CAP_SYS_RESOURCE))
  75                                 return -EPERM;
  76                 }
  77
  78
  79                 handle = ext3_journal_start(inode, 1);
  80                 if (IS_ERR(handle))
  81                         return PTR_ERR(handle);
  82                 if (IS_SYNC(inode))
  83                         handle->h_sync = 1;
  84                 err = ext3_reserve_inode_write(handle, inode, &iloc);
  85                 if (err)
  86                         goto flags_err;
  87
  88                 flags = flags & EXT3_FL_USER_MODIFIABLE;
  89                 flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
  90                 ei->i_flags = flags;
  91
  92                 ext3_set_inode_flags(inode);
  93                 inode->i_ctime = CURRENT_TIME_SEC;
  94
  95                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
  96 flags_err:
  97                 ext3_journal_stop(handle);
  98                 if (err)
  99                         return err;
 100
 101                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
 102                         err = ext3_change_inode_journal_flag(inode, jflag);
 103                 return err;
 104         }
 105         case EXT3_IOC_GETVERSION:
 106         case EXT3_IOC_GETVERSION_OLD:
 107                 return put_user(inode->i_generation, (int __user *) arg);
 108         case EXT3_IOC_SETVERSION:
 109         case EXT3_IOC_SETVERSION_OLD: {
 110                 handle_t *handle;
 111                 struct ext3_iloc iloc;
 112                 __u32 generation;
 113                 int err;
 114
 115                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 116                         return -EPERM;
 117                 if (IS_RDONLY(inode))
 118                         return -EROFS;
 119                 if (get_user(generation, (int __user *) arg))
 120                         return -EFAULT;
 121
 122                 handle = ext3_journal_start(inode, 1);
 123                 if (IS_ERR(handle))
 124                         return PTR_ERR(handle);
 125                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 126                 if (err == 0) {
 127                         inode->i_ctime = CURRENT_TIME_SEC;
 128                         inode->i_generation = generation;
 129                         err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 130                 }
 131                 ext3_journal_stop(handle);
 132                 return err;
 133         }
 134 #ifdef CONFIG_JBD_DEBUG
 135         case EXT3_IOC_WAIT_FOR_READONLY:
 136                 /*
 137                  * This is racy - by the time we're woken up and running,
 138                  * the superblock could be released.  And the module could
 139                  * have been unloaded.  So sue me.
 140                  *
 141                  * Returns 1 if it slept, else zero.
 142                  */
 143                 {
 144                         struct super_block *sb = inode->i_sb;
 145                         DECLARE_WAITQUEUE(wait, current);
 146                         int ret = 0;
 147
 148                         set_current_state(TASK_INTERRUPTIBLE);
 149                         add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 150                         if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
 151                                 schedule();
 152                                 ret = 1;
 153                         }
 154                         remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 155                         return ret;
 156                 }
 157 #endif
 158         case EXT3_IOC_GETRSVSZ:
 159                 if (test_opt(inode->i_sb, RESERVATION) && S_ISREG(inode->i_mode)) {
 160                         rsv_window_size = atomic_read(&ei->i_rsv_window.rsv_goal_size);
 161                         return put_user(rsv_window_size, (int __user *)arg);
 162                 }
 163                 return -ENOTTY;
 164         case EXT3_IOC_SETRSVSZ:
 165                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 166                         return -ENOTTY;
 167
 168                 if (IS_RDONLY(inode))
 169                         return -EROFS;
 170
 171                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 172                         return -EACCES;
 173
 174                 if (get_user(rsv_window_size, (int __user *)arg))
 175                         return -EFAULT;
 176
 177                 if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
 178                         rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
 179                 atomic_set(&ei->i_rsv_window.rsv_goal_size, rsv_window_size);
 180                 return 0;
 181         case EXT3_IOC_GROUP_EXTEND: {
 182                 unsigned long n_blocks_count;
 183                 struct super_block *sb = inode->i_sb;
 184                 int err;
 185
 186                 if (!capable(CAP_SYS_RESOURCE))
 187                         return -EPERM;
 188
 189                 if (IS_RDONLY(inode))
 190                         return -EROFS;
 191
 192                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 193                         return -EFAULT;
 194
 195                 err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
 196                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 197                 journal_flush(EXT3_SB(sb)->s_journal);
 198                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 199
 200                 return err;
 201         }
 202         case EXT3_IOC_GROUP_ADD: {
 203                 struct ext3_new_group_data input;
 204                 struct super_block *sb = inode->i_sb;
 205                 int err;
 206
 207                 if (!capable(CAP_SYS_RESOURCE))
 208                         return -EPERM;
 209
 210                 if (IS_RDONLY(inode))
 211                         return -EROFS;
 212
 213                 if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
 214                                 sizeof(input)))
 215                         return -EFAULT;
 216
 217                 err = ext3_group_add(sb, &input);
 218                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 219                 journal_flush(EXT3_SB(sb)->s_journal);
 220                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 221
 222                 return err;
 223         }
 224
 225 #if defined(CONFIG_VSERVER_LEGACY) && !defined(CONFIG_INOXID_NONE)
 226         case EXT3_IOC_SETXID: {
 227                 handle_t *handle;
 228                 struct ext3_iloc iloc;
 229                 int xid;
 230                 int err;
 231
 232                 /* fixme: if stealth, return -ENOTTY */
 233                 if (!capable(CAP_CONTEXT))
 234                         return -EPERM;
 235                 if (IS_RDONLY(inode))
 236                         return -EROFS;
 237                 if (!(inode->i_sb->s_flags & MS_TAGXID))
 238                         return -ENOSYS;
 239                 if (get_user(xid, (int *) arg))
 240                         return -EFAULT;
 241
 242                 handle = ext3_journal_start(inode, 1);
 243                 if (IS_ERR(handle))
 244                         return PTR_ERR(handle);
 245                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 246                 if (err)
 247                         return err;
 248
 249                 inode->i_xid = (xid & 0xFFFF);
 250                 inode->i_ctime = CURRENT_TIME;
 251
 252                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 253                 ext3_journal_stop(handle);
 254                 return err;
 255         }
 256 #endif
 257
 258         default:
 259                 return -ENOTTY;
 260         }
 261 }