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 <asm/uaccess.h>
  16
  17
  18 int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  19                 unsigned long arg)
  20 {
  21         struct ext3_inode_info *ei = EXT3_I(inode);
  22         unsigned int flags;
  23         unsigned short rsv_window_size;
  24
  25         ext3_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  26
  27         switch (cmd) {
  28         case EXT3_IOC_GETFLAGS:
  29                 flags = ei->i_flags & EXT3_FL_USER_VISIBLE;
  30                 return put_user(flags, (int *) arg);
  31         case EXT3_IOC_SETFLAGS: {
  32                 handle_t *handle = NULL;
  33                 int err;
  34                 struct ext3_iloc iloc;
  35                 unsigned int oldflags;
  36                 unsigned int jflag;
  37
  38                 if (IS_RDONLY(inode))
  39                         return -EROFS;
  40
  41                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  42                         return -EACCES;
  43
  44                 if (get_user(flags, (int *) arg))
  45                         return -EFAULT;
  46
  47                 if (!S_ISDIR(inode->i_mode))
  48                         flags &= ~EXT3_DIRSYNC_FL;
  49
  50                 oldflags = ei->i_flags;
  51
  52                 /* The JOURNAL_DATA flag is modifiable only by root */
  53                 jflag = flags & EXT3_JOURNAL_DATA_FL;
  54
  55                 /*
  56                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  57                  * the relevant capability.
  58                  *
  59                  * This test looks nicer. Thanks to Pauline Middelink
  60                  */
  61                 if ((flags ^ oldflags) & (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL)) {
  62                         if (!capable(CAP_LINUX_IMMUTABLE))
  63                                 return -EPERM;
  64                 }
  65
  66                 /*
  67                  * The JOURNAL_DATA flag can only be changed by
  68                  * the relevant capability.
  69                  */
  70                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
  71                         if (!capable(CAP_SYS_RESOURCE))
  72                                 return -EPERM;
  73                 }
  74
  75
  76                 handle = ext3_journal_start(inode, 1);
  77                 if (IS_ERR(handle))
  78                         return PTR_ERR(handle);
  79                 if (IS_SYNC(inode))
  80                         handle->h_sync = 1;
  81                 err = ext3_reserve_inode_write(handle, inode, &iloc);
  82                 if (err)
  83                         goto flags_err;
  84
  85                 flags = flags & EXT3_FL_USER_MODIFIABLE;
  86                 flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
  87                 ei->i_flags = flags;
  88
  89                 ext3_set_inode_flags(inode);
  90                 inode->i_ctime = CURRENT_TIME;
  91
  92                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
  93 flags_err:
  94                 ext3_journal_stop(handle);
  95                 if (err)
  96                         return err;
  97
  98                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
  99                         err = ext3_change_inode_journal_flag(inode, jflag);
 100                 return err;
 101         }
 102         case EXT3_IOC_GETVERSION:
 103         case EXT3_IOC_GETVERSION_OLD:
 104                 return put_user(inode->i_generation, (int *) arg);
 105         case EXT3_IOC_SETVERSION:
 106         case EXT3_IOC_SETVERSION_OLD: {
 107                 handle_t *handle;
 108                 struct ext3_iloc iloc;
 109                 __u32 generation;
 110                 int err;
 111
 112                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 113                         return -EPERM;
 114                 if (IS_RDONLY(inode))
 115                         return -EROFS;
 116                 if (get_user(generation, (int *) arg))
 117                         return -EFAULT;
 118
 119                 handle = ext3_journal_start(inode, 1);
 120                 if (IS_ERR(handle))
 121                         return PTR_ERR(handle);
 122                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 123                 if (err == 0) {
 124                         inode->i_ctime = CURRENT_TIME;
 125                         inode->i_generation = generation;
 126                         err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 127                 }
 128                 ext3_journal_stop(handle);
 129                 return err;
 130         }
 131 #ifdef CONFIG_JBD_DEBUG
 132         case EXT3_IOC_WAIT_FOR_READONLY:
 133                 /*
 134                  * This is racy - by the time we're woken up and running,
 135                  * the superblock could be released.  And the module could
 136                  * have been unloaded.  So sue me.
 137                  *
 138                  * Returns 1 if it slept, else zero.
 139                  */
 140                 {
 141                         struct super_block *sb = inode->i_sb;
 142                         DECLARE_WAITQUEUE(wait, current);
 143                         int ret = 0;
 144
 145                         set_current_state(TASK_INTERRUPTIBLE);
 146                         add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 147                         if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
 148                                 schedule();
 149                                 ret = 1;
 150                         }
 151                         remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 152                         return ret;
 153                 }
 154 #endif
 155         case EXT3_IOC_GETRSVSZ:
 156                 if (test_opt(inode->i_sb, RESERVATION) && S_ISREG(inode->i_mode)) {
 157                         rsv_window_size = atomic_read(&ei->i_rsv_window.rsv_goal_size);
 158                         return put_user(rsv_window_size, (int *)arg);
 159                 }
 160                 return -ENOTTY;
 161         case EXT3_IOC_SETRSVSZ:
 162                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 163                         return -ENOTTY;
 164
 165                 if (IS_RDONLY(inode))
 166                         return -EROFS;
 167
 168                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 169                         return -EACCES;
 170
 171                 if (get_user(rsv_window_size, (int *)arg))
 172                         return -EFAULT;
 173
 174                 if (rsv_window_size > EXT3_MAX_RESERVE_BLOCKS)
 175                         rsv_window_size = EXT3_MAX_RESERVE_BLOCKS;
 176                 atomic_set(&ei->i_rsv_window.rsv_goal_size, rsv_window_size);
 177                 return 0;
 178         case EXT3_IOC_GROUP_EXTEND: {
 179                 unsigned long n_blocks_count;
 180                 struct super_block *sb = inode->i_sb;
 181                 int err;
 182
 183                 if (!capable(CAP_SYS_RESOURCE))
 184                         return -EACCES;
 185
 186                 if (sb->s_flags & MS_RDONLY)
 187                         return -EROFS;
 188
 189                 if (get_user(n_blocks_count, (__u32 *)arg))
 190                         return -EFAULT;
 191
 192                 err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count);
 193                 journal_lock_updates(EXT3_SB(sb)->s_journal);
 194                 journal_flush(EXT3_SB(sb)->s_journal);
 195                 journal_unlock_updates(EXT3_SB(sb)->s_journal);
 196
 197                 return err;
 198         }
 199         case EXT3_IOC_GROUP_ADD: {
 200                 struct ext3_new_group_data input;
 201                 struct super_block *sb = inode->i_sb;
 202                 int err;
 203
 204                 if (!capable(CAP_SYS_RESOURCE))
 205                         return -EACCES;
 206
 207                 if (inode->i_sb->s_flags & MS_RDONLY)
 208                         return -EROFS;
 209
 210                 if (copy_from_user(&input, (struct ext3_new_group_input *)arg,
 211                                 sizeof(input)))
 212                         return -EFAULT;
 213
 214                 err = ext3_group_add(sb, &input);
 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
 222
 223         default:
 224                 return -ENOTTY;
 225         }
 226 }