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
  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 __user *) 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 __user *) 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 ((oldflags & EXT3_IMMUTABLE_FL) ||
  62                         ((flags ^ oldflags) &
  63                         (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL))) {
  64                         if (!capable(CAP_LINUX_IMMUTABLE))
  65                                 return -EPERM;
  66                 }
  67
  68                 /*
  69                  * The JOURNAL_DATA flag can only be changed by
  70                  * the relevant capability.
  71                  */
  72                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
  73                         if (!capable(CAP_SYS_RESOURCE))
  74                                 return -EPERM;
  75                 }
  76
  77
  78                 handle = ext3_journal_start(inode, 1);
  79                 if (IS_ERR(handle))
  80                         return PTR_ERR(handle);
  81                 if (IS_SYNC(inode))
  82                         handle->h_sync = 1;
  83                 err = ext3_reserve_inode_write(handle, inode, &iloc);
  84                 if (err)
  85                         goto flags_err;
  86
  87                 flags = flags & EXT3_FL_USER_MODIFIABLE;
  88                 flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
  89                 ei->i_flags = flags;
  90
  91                 ext3_set_inode_flags(inode);
  92                 inode->i_ctime = CURRENT_TIME;
  93
  94                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
  95 flags_err:
  96                 ext3_journal_stop(handle);
  97                 if (err)
  98                         return err;
  99
 100                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
 101                         err = ext3_change_inode_journal_flag(inode, jflag);
 102                 return err;
 103         }
 104         case EXT3_IOC_GETVERSION:
 105         case EXT3_IOC_GETVERSION_OLD:
 106                 return put_user(inode->i_generation, (int __user *) arg);
 107         case EXT3_IOC_SETVERSION:
 108         case EXT3_IOC_SETVERSION_OLD: {
 109                 handle_t *handle;
 110                 struct ext3_iloc iloc;
 111                 __u32 generation;
 112                 int err;
 113
 114                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 115                         return -EPERM;
 116                 if (IS_RDONLY(inode))
 117                         return -EROFS;
 118                 if (get_user(generation, (int __user *) arg))
 119                         return -EFAULT;
 120
 121                 handle = ext3_journal_start(inode, 1);
 122                 if (IS_ERR(handle))
 123                         return PTR_ERR(handle);
 124                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 125                 if (err == 0) {
 126                         inode->i_ctime = CURRENT_TIME;
 127                         inode->i_generation = generation;
 128                         err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 129                 }
 130                 ext3_journal_stop(handle);
 131                 return err;
 132         }
 133 #ifdef CONFIG_JBD_DEBUG
 134         case EXT3_IOC_WAIT_FOR_READONLY:
 135                 /*
 136                  * This is racy - by the time we're woken up and running,
 137                  * the superblock could be released.  And the module could
 138                  * have been unloaded.  So sue me.
 139                  *
 140                  * Returns 1 if it slept, else zero.
 141                  */
 142                 {
 143                         struct super_block *sb = inode->i_sb;
 144                         DECLARE_WAITQUEUE(wait, current);
 145                         int ret = 0;
 146
 147                         set_current_state(TASK_INTERRUPTIBLE);
 148                         add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 149                         if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
 150                                 schedule();
 151                                 ret = 1;
 152                         }
 153                         remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 154                         return ret;
 155                 }
 156 #endif
 157 #if defined(CONFIG_VSERVER_LEGACY) && !defined(CONFIG_INOXID_NONE)
 158         case EXT3_IOC_SETXID: {
 159                 handle_t *handle;
 160                 struct ext3_iloc iloc;
 161                 int xid;
 162                 int err;
 163
 164                 /* fixme: if stealth, return -ENOTTY */
 165                 if (!capable(CAP_CONTEXT))
 166                         return -EPERM;
 167                 if (IS_RDONLY(inode))
 168                         return -EROFS;
 169                 if (!(inode->i_sb->s_flags & MS_TAGXID))
 170                         return -ENOSYS;
 171                 if (get_user(xid, (int *) arg))
 172                         return -EFAULT;
 173
 174                 handle = ext3_journal_start(inode, 1);
 175                 if (IS_ERR(handle))
 176                         return PTR_ERR(handle);
 177                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 178                 if (err)
 179                         return err;
 180
 181                 inode->i_xid = (xid & 0xFFFF);
 182                 inode->i_ctime = CURRENT_TIME;
 183
 184                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 185                 ext3_journal_stop(handle);
 186                 return err;
 187         }
 188 #endif
 189         default:
 190                 return -ENOTTY;
 191         }
 192 }