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/capability.h>
  13 #include <linux/ext3_fs.h>
  14 #include <linux/ext3_jbd.h>
  15 #include <linux/time.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                 mutex_lock(&inode->i_mutex);
  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 ((flags ^ oldflags) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) {
  64                         if (!capable(CAP_LINUX_IMMUTABLE)) {
  65                                 mutex_unlock(&inode->i_mutex);
  66                                 return -EPERM;
  67                         }
  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                                 mutex_unlock(&inode->i_mutex);
  77                                 return -EPERM;
  78                         }
  79                 }
  80
  81
  82                 handle = ext3_journal_start(inode, 1);
  83                 if (IS_ERR(handle)) {
  84                         mutex_unlock(&inode->i_mutex);
  85                         return PTR_ERR(handle);
  86                 }
  87                 if (IS_SYNC(inode))
  88                         handle->h_sync = 1;
  89                 err = ext3_reserve_inode_write(handle, inode, &iloc);
  90                 if (err)
  91                         goto flags_err;
  92
  93                 flags = flags & EXT3_FL_USER_MODIFIABLE;
  94                 flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
  95                 ei->i_flags = flags;
  96
  97                 ext3_set_inode_flags(inode);
  98                 inode->i_ctime = CURRENT_TIME_SEC;
  99
 100                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 101 flags_err:
 102                 ext3_journal_stop(handle);
 103                 if (err) {
 104                         mutex_unlock(&inode->i_mutex);
 105                         return err;
 106                 }
 107
 108                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
 109                         err = ext3_change_inode_journal_flag(inode, jflag);
 110                 mutex_unlock(&inode->i_mutex);
 111                 return err;
 112         }
 113         case EXT3_IOC_GETVERSION:
 114         case EXT3_IOC_GETVERSION_OLD:
 115                 return put_user(inode->i_generation, (int __user *) arg);
 116         case EXT3_IOC_SETVERSION:
 117         case EXT3_IOC_SETVERSION_OLD: {
 118                 handle_t *handle;
 119                 struct ext3_iloc iloc;
 120                 __u32 generation;
 121                 int err;
 122
 123                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 124                         return -EPERM;
 125                 if (IS_RDONLY(inode))
 126                         return -EROFS;
 127                 if (get_user(generation, (int __user *) arg))
 128                         return -EFAULT;
 129
 130                 handle = ext3_journal_start(inode, 1);
 131                 if (IS_ERR(handle))
 132                         return PTR_ERR(handle);
 133                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 134                 if (err == 0) {
 135                         inode->i_ctime = CURRENT_TIME_SEC;
 136                         inode->i_generation = generation;
 137                         err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 138                 }
 139                 ext3_journal_stop(handle);
 140                 return err;
 141         }
 142 #ifdef CONFIG_JBD_DEBUG
 143         case EXT3_IOC_WAIT_FOR_READONLY:
 144                 /*
 145                  * This is racy - by the time we're woken up and running,
 146                  * the superblock could be released.  And the module could
 147                  * have been unloaded.  So sue me.
 148                  *
 149                  * Returns 1 if it slept, else zero.
 150                  */
 151                 {
 152                         struct super_block *sb = inode->i_sb;
 153                         DECLARE_WAITQUEUE(wait, current);
 154                         int ret = 0;
 155
 156                         set_current_state(TASK_INTERRUPTIBLE);
 157                         add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 158                         if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
 159                                 schedule();
 160                                 ret = 1;
 161                         }
 162                         remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 163                         return ret;
 164                 }
 165 #endif
 166         case EXT3_IOC_GETRSVSZ:
 167                 if (test_opt(inode->i_sb, RESERVATION)
 168                         && S_ISREG(inode->i_mode)
 169                         && ei->i_block_alloc_info) {
 170                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 171                         return put_user(rsv_window_size, (int __user *)arg);
 172                 }
 173                 return -ENOTTY;
 174         case EXT3_IOC_SETRSVSZ: {
 175
 176                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 177                         return -ENOTTY;
 178
 179                 if (IS_RDONLY(inode))
 180                         return -EROFS;
 181
 182                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 183                         return -EACCES;
 184
 185                 if (get_user(rsv_window_size, (int __user *)arg))
 186                         return -EFAULT;
 187
 188                 if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
 189                         rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
 190
 191                 /*
 192                  * need to allocate reservation structure for this inode
 193                  * before set the window size
 194                  */
 195                 mutex_lock(&ei->truncate_mutex);
 196                 if (!ei->i_block_alloc_info)
 197                         ext3_init_block_alloc_info(inode);
 198
 199                 if (ei->i_block_alloc_info){
 200                         struct ext3_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 201                         rsv->rsv_goal_size = rsv_window_size;
 202                 }
 203                 mutex_unlock(&ei->truncate_mutex);
 204                 return 0;
 205         }
 206         case EXT3_IOC_GROUP_EXTEND: {
 207                 unsigned long n_blocks_count;
 208                 struct super_block *sb = inode->i_sb;
 209                 int err;
 210
 211                 if (!capable(CAP_SYS_RESOURCE))
 212                         return -EPERM;
 213
 214                 if (IS_RDONLY(inode))
 215                         return -EROFS;
 216
 217                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 218                         return -EFAULT;
 219
 220                 err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
 221                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 222                 journal_flush(EXT3_SB(sb)->s_journal);
 223                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 224
 225                 return err;
 226         }
 227         case EXT3_IOC_GROUP_ADD: {
 228                 struct ext3_new_group_data input;
 229                 struct super_block *sb = inode->i_sb;
 230                 int err;
 231
 232                 if (!capable(CAP_SYS_RESOURCE))
 233                         return -EPERM;
 234
 235                 if (IS_RDONLY(inode))
 236                         return -EROFS;
 237
 238                 if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
 239                                 sizeof(input)))
 240                         return -EFAULT;
 241
 242                 err = ext3_group_add(sb, &input);
 243                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 244                 journal_flush(EXT3_SB(sb)->s_journal);
 245                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 246
 247                 return err;
 248         }
 249
 250
 251         default:
 252                 return -ENOTTY;
 253         }
 254 }