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                 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 ((flags ^ oldflags) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) {
  63                         if (!capable(CAP_LINUX_IMMUTABLE))
  64                                 return -EPERM;
  65                 }
  66
  67                 /*
  68                  * The JOURNAL_DATA flag can only be changed by
  69                  * the relevant capability.
  70                  */
  71                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
  72                         if (!capable(CAP_SYS_RESOURCE))
  73                                 return -EPERM;
  74                 }
  75
  76
  77                 handle = ext3_journal_start(inode, 1);
  78                 if (IS_ERR(handle))
  79                         return PTR_ERR(handle);
  80                 if (IS_SYNC(inode))
  81                         handle->h_sync = 1;
  82                 err = ext3_reserve_inode_write(handle, inode, &iloc);
  83                 if (err)
  84                         goto flags_err;
  85
  86                 flags = flags & EXT3_FL_USER_MODIFIABLE;
  87                 flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
  88                 ei->i_flags = flags;
  89
  90                 ext3_set_inode_flags(inode);
  91                 inode->i_ctime = CURRENT_TIME_SEC;
  92
  93                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
  94 flags_err:
  95                 ext3_journal_stop(handle);
  96                 if (err)
  97                         return err;
  98
  99                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
 100                         err = ext3_change_inode_journal_flag(inode, jflag);
 101                 return err;
 102         }
 103         case EXT3_IOC_GETVERSION:
 104         case EXT3_IOC_GETVERSION_OLD:
 105                 return put_user(inode->i_generation, (int __user *) arg);
 106         case EXT3_IOC_SETVERSION:
 107         case EXT3_IOC_SETVERSION_OLD: {
 108                 handle_t *handle;
 109                 struct ext3_iloc iloc;
 110                 __u32 generation;
 111                 int err;
 112
 113                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 114                         return -EPERM;
 115                 if (IS_RDONLY(inode))
 116                         return -EROFS;
 117                 if (get_user(generation, (int __user *) arg))
 118                         return -EFAULT;
 119
 120                 handle = ext3_journal_start(inode, 1);
 121                 if (IS_ERR(handle))
 122                         return PTR_ERR(handle);
 123                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 124                 if (err == 0) {
 125                         inode->i_ctime = CURRENT_TIME_SEC;
 126                         inode->i_generation = generation;
 127                         err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 128                 }
 129                 ext3_journal_stop(handle);
 130                 return err;
 131         }
 132 #ifdef CONFIG_JBD_DEBUG
 133         case EXT3_IOC_WAIT_FOR_READONLY:
 134                 /*
 135                  * This is racy - by the time we're woken up and running,
 136                  * the superblock could be released.  And the module could
 137                  * have been unloaded.  So sue me.
 138                  *
 139                  * Returns 1 if it slept, else zero.
 140                  */
 141                 {
 142                         struct super_block *sb = inode->i_sb;
 143                         DECLARE_WAITQUEUE(wait, current);
 144                         int ret = 0;
 145
 146                         set_current_state(TASK_INTERRUPTIBLE);
 147                         add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 148                         if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
 149                                 schedule();
 150                                 ret = 1;
 151                         }
 152                         remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 153                         return ret;
 154                 }
 155 #endif
 156         case EXT3_IOC_GETRSVSZ:
 157                 if (test_opt(inode->i_sb, RESERVATION)
 158                         && S_ISREG(inode->i_mode)
 159                         && ei->i_block_alloc_info) {
 160                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 161                         return put_user(rsv_window_size, (int __user *)arg);
 162                 }
 163                 return -ENOTTY;
 164         case EXT3_IOC_SETRSVSZ: {
 165
 166                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 167                         return -ENOTTY;
 168
 169                 if (IS_RDONLY(inode))
 170                         return -EROFS;
 171
 172                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 173                         return -EACCES;
 174
 175                 if (get_user(rsv_window_size, (int __user *)arg))
 176                         return -EFAULT;
 177
 178                 if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
 179                         rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
 180
 181                 /*
 182                  * need to allocate reservation structure for this inode
 183                  * before set the window size
 184                  */
 185                 mutex_lock(&ei->truncate_mutex);
 186                 if (!ei->i_block_alloc_info)
 187                         ext3_init_block_alloc_info(inode);
 188
 189                 if (ei->i_block_alloc_info){
 190                         struct ext3_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 191                         rsv->rsv_goal_size = rsv_window_size;
 192                 }
 193                 mutex_unlock(&ei->truncate_mutex);
 194                 return 0;
 195         }
 196         case EXT3_IOC_GROUP_EXTEND: {
 197                 unsigned long n_blocks_count;
 198                 struct super_block *sb = inode->i_sb;
 199                 int err;
 200
 201                 if (!capable(CAP_SYS_RESOURCE))
 202                         return -EPERM;
 203
 204                 if (IS_RDONLY(inode))
 205                         return -EROFS;
 206
 207                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 208                         return -EFAULT;
 209
 210                 err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
 211                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 212                 journal_flush(EXT3_SB(sb)->s_journal);
 213                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 214
 215                 return err;
 216         }
 217         case EXT3_IOC_GROUP_ADD: {
 218                 struct ext3_new_group_data input;
 219                 struct super_block *sb = inode->i_sb;
 220                 int err;
 221
 222                 if (!capable(CAP_SYS_RESOURCE))
 223                         return -EPERM;
 224
 225                 if (IS_RDONLY(inode))
 226                         return -EROFS;
 227
 228                 if (copy_from_user(&input, (struct ext3_new_group_input __user *)arg,
 229                                 sizeof(input)))
 230                         return -EFAULT;
 231
 232                 err = ext3_group_add(sb, &input);
 233                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 234                 journal_flush(EXT3_SB(sb)->s_journal);
 235                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 236
 237                 return err;
 238         }
 239
 240
 241         default:
 242                 return -ENOTTY;
 243         }
 244 }