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                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
  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 ((oldflags & EXT3_IMMUTABLE_FL) ||
  63                         ((flags ^ oldflags) &
  64                         (EXT3_APPEND_FL | EXT3_IMMUTABLE_FL))) {
  65                         if (!capable(CAP_LINUX_IMMUTABLE))
  66                                 return -EPERM;
  67                 }
  68
  69                 /*
  70                  * The JOURNAL_DATA flag can only be changed by
  71                  * the relevant capability.
  72                  */
  73                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL)) {
  74                         if (!capable(CAP_SYS_RESOURCE))
  75                                 return -EPERM;
  76                 }
  77
  78
  79                 handle = ext3_journal_start(inode, 1);
  80                 if (IS_ERR(handle))
  81                         return PTR_ERR(handle);
  82                 if (IS_SYNC(inode))
  83                         handle->h_sync = 1;
  84                 err = ext3_reserve_inode_write(handle, inode, &iloc);
  85                 if (err)
  86                         goto flags_err;
  87
  88                 flags = flags & EXT3_FL_USER_MODIFIABLE;
  89                 flags |= oldflags & ~EXT3_FL_USER_MODIFIABLE;
  90                 ei->i_flags = flags;
  91
  92                 ext3_set_inode_flags(inode);
  93                 inode->i_ctime = CURRENT_TIME;
  94
  95                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
  96 flags_err:
  97                 ext3_journal_stop(handle);
  98                 if (err)
  99                         return err;
 100
 101                 if ((jflag ^ oldflags) & (EXT3_JOURNAL_DATA_FL))
 102                         err = ext3_change_inode_journal_flag(inode, jflag);
 103                 return err;
 104         }
 105         case EXT3_IOC_GETVERSION:
 106         case EXT3_IOC_GETVERSION_OLD:
 107                 return put_user(inode->i_generation, (int __user *) arg);
 108         case EXT3_IOC_SETVERSION:
 109         case EXT3_IOC_SETVERSION_OLD: {
 110                 handle_t *handle;
 111                 struct ext3_iloc iloc;
 112                 __u32 generation;
 113                 int err;
 114
 115                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 116                         return -EPERM;
 117                 if (IS_RDONLY(inode) ||
 118                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 119                         return -EROFS;
 120                 if (get_user(generation, (int __user *) arg))
 121                         return -EFAULT;
 122
 123                 handle = ext3_journal_start(inode, 1);
 124                 if (IS_ERR(handle))
 125                         return PTR_ERR(handle);
 126                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 127                 if (err == 0) {
 128                         inode->i_ctime = CURRENT_TIME;
 129                         inode->i_generation = generation;
 130                         err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 131                 }
 132                 ext3_journal_stop(handle);
 133                 return err;
 134         }
 135 #ifdef CONFIG_JBD_DEBUG
 136         case EXT3_IOC_WAIT_FOR_READONLY:
 137                 /*
 138                  * This is racy - by the time we're woken up and running,
 139                  * the superblock could be released.  And the module could
 140                  * have been unloaded.  So sue me.
 141                  *
 142                  * Returns 1 if it slept, else zero.
 143                  */
 144                 {
 145                         struct super_block *sb = inode->i_sb;
 146                         DECLARE_WAITQUEUE(wait, current);
 147                         int ret = 0;
 148
 149                         set_current_state(TASK_INTERRUPTIBLE);
 150                         add_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 151                         if (timer_pending(&EXT3_SB(sb)->turn_ro_timer)) {
 152                                 schedule();
 153                                 ret = 1;
 154                         }
 155                         remove_wait_queue(&EXT3_SB(sb)->ro_wait_queue, &wait);
 156                         return ret;
 157                 }
 158 #endif
 159 #if defined(CONFIG_VSERVER_LEGACY) && !defined(CONFIG_INOXID_NONE)
 160         case EXT3_IOC_SETXID: {
 161                 handle_t *handle;
 162                 struct ext3_iloc iloc;
 163                 int xid;
 164                 int err;
 165
 166                 /* fixme: if stealth, return -ENOTTY */
 167                 if (!capable(CAP_CONTEXT))
 168                         return -EPERM;
 169                 if (IS_RDONLY(inode))
 170                         return -EROFS;
 171                 if (!(inode->i_sb->s_flags & MS_TAGXID))
 172                         return -ENOSYS;
 173                 if (get_user(xid, (int *) arg))
 174                         return -EFAULT;
 175
 176                 handle = ext3_journal_start(inode, 1);
 177                 if (IS_ERR(handle))
 178                         return PTR_ERR(handle);
 179                 err = ext3_reserve_inode_write(handle, inode, &iloc);
 180                 if (err)
 181                         return err;
 182
 183                 inode->i_xid = (xid & 0xFFFF);
 184                 inode->i_ctime = CURRENT_TIME;
 185
 186                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
 187                 ext3_journal_stop(handle);
 188                 return err;
 189         }
 190 #endif
 191         default:
 192                 return -ENOTTY;
 193         }
 194 }