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/mount.h>
  12 #include <linux/jbd.h>
  13 #include <linux/capability.h>
  14 #include <linux/ext3_fs.h>
  15 #include <linux/ext3_jbd.h>
  16 #include <linux/time.h>
  17 #include <linux/vserver/xid.h>
  18 #include <asm/uaccess.h>
  19
  20
  21 int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  22                 unsigned long arg)
  23 {
  24         struct ext3_inode_info *ei = EXT3_I(inode);
  25         unsigned int flags;
  26         unsigned short rsv_window_size;
  27
  28         ext3_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  29
  30         switch (cmd) {
  31         case EXT3_IOC_GETFLAGS:
  32                 flags = ei->i_flags & EXT3_FL_USER_VISIBLE;
  33                 return put_user(flags, (int __user *) arg);
  34         case EXT3_IOC_SETFLAGS: {
  35                 handle_t *handle = NULL;
  36                 int err;
  37                 struct ext3_iloc iloc;
  38                 unsigned int oldflags;
  39                 unsigned int jflag;
  40
  41                 if (IS_RDONLY(inode) ||
  42                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
  43                         return -EROFS;
  44
  45                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  46                         return -EACCES;
  47
  48                 if (get_user(flags, (int __user *) arg))
  49                         return -EFAULT;
  50
  51                 if (!S_ISDIR(inode->i_mode))
  52                         flags &= ~EXT3_DIRSYNC_FL;
  53
  54                 oldflags = ei->i_flags;
  55
  56                 /* The JOURNAL_DATA flag is modifiable only by root */
  57                 jflag = flags & EXT3_JOURNAL_DATA_FL;
  58
  59                 /*
  60                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  61                  * the relevant capability.
  62                  *
  63                  * This test looks nicer. Thanks to Pauline Middelink
  64                  */
  65                 if ((oldflags & EXT3_IMMUTABLE_FL) ||
  66                         ((flags ^ oldflags) & (EXT3_APPEND_FL |
  67                         EXT3_IMMUTABLE_FL | EXT3_IUNLINK_FL))) {
  68                         if (!capable(CAP_LINUX_IMMUTABLE))
  69                                 return -EPERM;
  70                 }
  71
  72                 /*
  73                  * The JOURNAL_DATA flag can only be changed by
  74                  * the relevant capability.
  75                  */
  76                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
  77                         if (!capable(CAP_SYS_RESOURCE))
  78                                 return -EPERM;
  79                 }
  80
  81
  82                 handle = ext3_journal_start(inode, 1);
  83                 if (IS_ERR(handle))
  84                         return PTR_ERR(handle);
  85                 if (IS_SYNC(inode))
  86                         handle->h_sync = 1;
  87                 err = ext3_reserve_inode_write(handle, inode, &iloc);
  88                 if (err)
  89                         goto flags_err;
  90
  91                 flags = flags & EXT3_FL_USER_MODIFIABLE;
  92                 flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
  93                 ei->i_flags = flags;
  94
  95                 ext3_set_inode_flags(inode);
  96                 inode->i_ctime = CURRENT_TIME_SEC;
  97
  98                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
  99 flags_err:
 100                 ext3_journal_stop(handle);
 101                 if (err)
 102                         return err;
 103
 104                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
 105                         err = ext3_change_inode_journal_flag(inode, jflag);
 106                 return err;
 107         }
 108         case EXT3_IOC_GETVERSION:
 109         case EXT3_IOC_GETVERSION_OLD:
 110                 return put_user(inode->i_generation, (int __user *) arg);
 111         case EXT3_IOC_SETVERSION:
 112         case EXT3_IOC_SETVERSION_OLD: {
 113                 handle_t *handle;
 114                 struct ext3_iloc iloc;
 115                 __u32 generation;
 116                 int err;
 117
 118                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 119                         return -EPERM;
 120                 if (IS_RDONLY(inode) ||
 121                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 122                         return -EROFS;
 123                 if (get_user(generation, (int __user *) arg))
 124                         return -EFAULT;
 125
 126                 handle = ext3_journal_start(inode, 1);
 127                 if (IS_ERR(handle))
 128                         return PTR_ERR(handle);
 129                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 130                 if (err == 0) {
 131                         inode->i_ctime = CURRENT_TIME_SEC;
 132                         inode->i_generation = generation;
 133                         err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 134                 }
 135                 ext3_journal_stop(handle);
 136                 return err;
 137         }
 138 #ifdef CONFIG_JBD_DEBUG
 139         case EXT3_IOC_WAIT_FOR_READONLY:
 140                 /*
 141                  * This is racy - by the time we're woken up and running,
 142                  * the superblock could be released.  And the module could
 143                  * have been unloaded.  So sue me.
 144                  *
 145                  * Returns 1 if it slept, else zero.
 146                  */
 147                 {
 148                         struct super_block *sb = inode->i_sb;
 149                         DECLARE_WAITQUEUE(wait, current);
 150                         int ret = 0;
 151
 152                         set_current_state(TASK_INTERRUPTIBLE);
 153                         add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 154                         if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
 155                                 schedule();
 156                                 ret = 1;
 157                         }
 158                         remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 159                         return ret;
 160                 }
 161 #endif
 162         case EXT3_IOC_GETRSVSZ:
 163                 if (test_opt(inode->i_sb, RESERVATION)
 164                         && S_ISREG(inode->i_mode)
 165                         && ei->i_block_alloc_info) {
 166                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 167                         return put_user(rsv_window_size, (int __user *)arg);
 168                 }
 169                 return -ENOTTY;
 170         case EXT3_IOC_SETRSVSZ: {
 171
 172                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 173                         return -ENOTTY;
 174
 175                 if (IS_RDONLY(inode) ||
 176                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 177                         return -EROFS;
 178
 179                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 180                         return -EACCES;
 181
 182                 if (get_user(rsv_window_size, (int __user *)arg))
 183                         return -EFAULT;
 184
 185                 if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
 186                         rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
 187
 188                 /*
 189                  * need to allocate reservation structure for this inode
 190                  * before set the window size
 191                  */
 192                 down(&ei->truncate_sem);
 193                 if (!ei->i_block_alloc_info)
 194                         ext3_init_block_alloc_info(inode);
 195
 196                 if (ei->i_block_alloc_info){
 197                         struct ext3_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 198                         rsv->rsv_goal_size = rsv_window_size;
 199                 }
 200                 up(&ei->truncate_sem);
 201                 return 0;
 202         }
 203         case EXT3_IOC_GROUP_EXTEND: {
 204                 unsigned long n_blocks_count;
 205                 struct super_block *sb = inode->i_sb;
 206                 int err;
 207
 208                 if (!capable(CAP_SYS_RESOURCE))
 209                         return -EPERM;
 210
 211                 if (IS_RDONLY(inode) ||
 212                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 213                         return -EROFS;
 214
 215                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 216                         return -EFAULT;
 217
 218                 err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
 219                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 220                 journal_flush(EXT3_SB(sb)->s_journal);
 221                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 222
 223                 return err;
 224         }
 225         case EXT3_IOC_GROUP_ADD: {
 226                 struct ext3_new_group_data input;
 227                 struct super_block *sb = inode->i_sb;
 228                 int err;
 229
 230                 if (!capable(CAP_SYS_RESOURCE))
 231                         return -EPERM;
 232
 233                 if (IS_RDONLY(inode) ||
 234                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 235                         return -EROFS;
 236
 237                 if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
 238                                 sizeof(input)))
 239                         return -EFAULT;
 240
 241                 err = ext3_group_add(sb, &input);
 242                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 243                 journal_flush(EXT3_SB(sb)->s_journal);
 244                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 245
 246                 return err;
 247         }
 248
 249 #if defined(CONFIG_VSERVER_LEGACY) && !defined(CONFIG_INOXID_NONE)
 250         case EXT3_IOC_SETXID: {
 251                 handle_t *handle;
 252                 struct ext3_iloc iloc;
 253                 int xid;
 254                 int err;
 255
 256                 /* fixme: if stealth, return -ENOTTY */
 257                 if (!capable(CAP_CONTEXT))
 258                         return -EPERM;
 259                 if (IS_RDONLY(inode))
 260                         return -EROFS;
 261                 if (!(inode->i_sb->s_flags & MS_TAGXID))
 262                         return -ENOSYS;
 263                 if (get_user(xid, (int __user *) arg))
 264                         return -EFAULT;
 265
 266                 handle = ext3_journal_start(inode, 1);
 267                 if (IS_ERR(handle))
 268                         return PTR_ERR(handle);
 269                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 270                 if (err)
 271                         return err;
 272
 273                 inode->i_xid = (xid & 0xFFFF);
 274                 inode->i_ctime = CURRENT_TIME;
 275
 276                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 277                 ext3_journal_stop(handle);
 278                 return err;
 279         }
 280 #endif
 281
 282         default:
 283                 return -ENOTTY;
 284         }
 285 }