fs/reiserfs/ioctl.c

   1 /*
   2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
   3  */
   4
   5 #include <linux/capability.h>
   6 #include <linux/fs.h>
   7 #include <linux/mount.h>
   8 #include <linux/reiserfs_fs.h>
   9 #include <linux/time.h>
  10 #include <asm/uaccess.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/smp_lock.h>
  13 #include <linux/compat.h>
  14
  15 static int reiserfs_unpack(struct inode *inode, struct file *filp);
  16
  17 /*
  18 ** reiserfs_ioctl - handler for ioctl for inode
  19 ** supported commands:
  20 **  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
  21 **                           and prevent packing file (argument arg has to be non-zero)
  22 **  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
  23 **  3) That's all for a while ...
  24 */
  25 int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
  26                    unsigned long arg)
  27 {
  28         unsigned int flags, oldflags;
  29
  30         switch (cmd) {
  31         case REISERFS_IOC_UNPACK:
  32                 if (S_ISREG(inode->i_mode)) {
  33                         if (arg)
  34                                 return reiserfs_unpack(inode, filp);
  35                         else
  36                                 return 0;
  37                 } else
  38                         return -ENOTTY;
  39                 /* following two cases are taken from fs/ext2/ioctl.c by Remy
  40                    Card (card@masi.ibp.fr) */
  41         case REISERFS_IOC_GETFLAGS:
  42                 if (!reiserfs_attrs(inode->i_sb))
  43                         return -ENOTTY;
  44
  45                 flags = REISERFS_I(inode)->i_attrs;
  46                 i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
  47                 flags &= REISERFS_FL_USER_VISIBLE;
  48                 return put_user(flags, (int __user *)arg);
  49         case REISERFS_IOC_SETFLAGS:{
  50                         if (!reiserfs_attrs(inode->i_sb))
  51                                 return -ENOTTY;
  52
  53                         if (IS_RDONLY(inode) ||
  54                                 (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
  55                                 return -EROFS;
  56
  57                         if ((current->fsuid != inode->i_uid)
  58                             && !capable(CAP_FOWNER))
  59                                 return -EPERM;
  60
  61                         if (get_user(flags, (int __user *)arg))
  62                                 return -EFAULT;
  63
  64                         oldflags = REISERFS_I(inode) -> i_attrs;
  65                         if (((oldflags & REISERFS_IMMUTABLE_FL) ||
  66                                 ((flags ^ oldflags) &
  67                                 (REISERFS_IMMUTABLE_FL | REISERFS_IUNLINK_FL |
  68                                  REISERFS_APPEND_FL))) &&
  69                                 !capable(CAP_LINUX_IMMUTABLE))
  70                                 return -EPERM;
  71
  72                         if ((flags & REISERFS_NOTAIL_FL) &&
  73                             S_ISREG(inode->i_mode)) {
  74                                 int result;
  75
  76                                 result = reiserfs_unpack(inode, filp);
  77                                 if (result)
  78                                         return result;
  79                         }
  80
  81                         flags = flags & REISERFS_FL_USER_MODIFIABLE;
  82                         flags |= oldflags & ~REISERFS_FL_USER_MODIFIABLE;
  83                         sd_attrs_to_i_attrs(flags, inode);
  84                         REISERFS_I(inode)->i_attrs = flags;
  85                         inode->i_ctime = CURRENT_TIME_SEC;
  86                         mark_inode_dirty(inode);
  87                         return 0;
  88                 }
  89         case REISERFS_IOC_GETVERSION:
  90                 return put_user(inode->i_generation, (int __user *)arg);
  91         case REISERFS_IOC_SETVERSION:
  92                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  93                         return -EPERM;
  94                 if (IS_RDONLY(inode) ||
  95                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
  96                         return -EROFS;
  97                 if (get_user(inode->i_generation, (int __user *)arg))
  98                         return -EFAULT;
  99                 inode->i_ctime = CURRENT_TIME_SEC;
 100                 mark_inode_dirty(inode);
 101                 return 0;
 102         default:
 103                 return -ENOTTY;
 104         }
 105 }
 106
 107 #ifdef CONFIG_COMPAT
 108 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 109                                 unsigned long arg)
 110 {
 111         struct inode *inode = file->f_path.dentry->d_inode;
 112         int ret;
 113
 114         /* These are just misnamed, they actually get/put from/to user an int */
 115         switch (cmd) {
 116         case REISERFS_IOC32_UNPACK:
 117                 cmd = REISERFS_IOC_UNPACK;
 118                 break;
 119         case REISERFS_IOC32_GETFLAGS:
 120                 cmd = REISERFS_IOC_GETFLAGS;
 121                 break;
 122         case REISERFS_IOC32_SETFLAGS:
 123                 cmd = REISERFS_IOC_SETFLAGS;
 124                 break;
 125         case REISERFS_IOC32_GETVERSION:
 126                 cmd = REISERFS_IOC_GETVERSION;
 127                 break;
 128         case REISERFS_IOC32_SETVERSION:
 129                 cmd = REISERFS_IOC_SETVERSION;
 130                 break;
 131         default:
 132                 return -ENOIOCTLCMD;
 133         }
 134         lock_kernel();
 135         ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 136         unlock_kernel();
 137         return ret;
 138 }
 139 #endif
 140
 141 /*
 142 ** reiserfs_unpack
 143 ** Function try to convert tail from direct item into indirect.
 144 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
 145 */
 146 static int reiserfs_unpack(struct inode *inode, struct file *filp)
 147 {
 148         int retval = 0;
 149         int index;
 150         struct page *page;
 151         struct address_space *mapping;
 152         unsigned long write_from;
 153         unsigned long blocksize = inode->i_sb->s_blocksize;
 154
 155         if (inode->i_size == 0) {
 156                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 157                 return 0;
 158         }
 159         /* ioctl already done */
 160         if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
 161                 return 0;
 162         }
 163
 164         /* we need to make sure nobody is changing the file size beneath
 165          ** us
 166          */
 167         mutex_lock(&inode->i_mutex);
 168         reiserfs_write_lock(inode->i_sb);
 169
 170         write_from = inode->i_size & (blocksize - 1);
 171         /* if we are on a block boundary, we are already unpacked.  */
 172         if (write_from == 0) {
 173                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 174                 goto out;
 175         }
 176
 177         /* we unpack by finding the page with the tail, and calling
 178          ** reiserfs_prepare_write on that page.  This will force a
 179          ** reiserfs_get_block to unpack the tail for us.
 180          */
 181         index = inode->i_size >> PAGE_CACHE_SHIFT;
 182         mapping = inode->i_mapping;
 183         page = grab_cache_page(mapping, index);
 184         retval = -ENOMEM;
 185         if (!page) {
 186                 goto out;
 187         }
 188         retval =
 189             mapping->a_ops->prepare_write(NULL, page, write_from, write_from);
 190         if (retval)
 191                 goto out_unlock;
 192
 193         /* conversion can change page contents, must flush */
 194         flush_dcache_page(page);
 195         retval =
 196             mapping->a_ops->commit_write(NULL, page, write_from, write_from);
 197         REISERFS_I(inode)->i_flags |= i_nopack_mask;
 198
 199       out_unlock:
 200         unlock_page(page);
 201         page_cache_release(page);
 202
 203       out:
 204         mutex_unlock(&inode->i_mutex);
 205         reiserfs_write_unlock(inode->i_sb);
 206         return retval;
 207 }