fsys_reiserfs.c

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#ifdef REISERDEBUG
  printf ("search_stat:\n  key %d:%d:0:0\n", dir_id, objectid);
#endif /* REISERDEBUG */
  
  depth = INFO->tree_depth;
  cache = ROOT;
  
  while (depth > DISK_LEAF_NODE_LEVEL)
    {
      struct key *key;
      nr_item = BLOCKHEAD (cache)->blk_nr_item;
      
      key = KEY (cache);
      
      for (i = 0; i < nr_item; i++) 
	{
	  if (key->k_dir_id > dir_id
	      || (key->k_dir_id == dir_id 
		  && (key->k_objectid > objectid
		      || (key->k_objectid == objectid
			  && (key->u.v1.k_offset
			      | key->u.v1.k_uniqueness) > 0))))
	    break;
	  key++;
	}
      
#ifdef REISERDEBUG
      printf ("  depth=%d, i=%d/%d\n", depth, i, nr_item);
#endif /* REISERDEBUG */
      INFO->next_key_nr[depth] = (i == nr_item) ? 0 : i+1;
      cache = read_tree_node (DC (cache)[i].dc_block_number, --depth);
      if (! cache)
	return 0;
    }
  
  /* cache == LEAF */
  nr_item = BLOCKHEAD (LEAF)->blk_nr_item;
  ih = ITEMHEAD;
  for (i = 0; i < nr_item; i++) 
    {
      if (ih->ih_key.k_dir_id == dir_id 
	  && ih->ih_key.k_objectid == objectid
	  && ih->ih_key.u.v1.k_offset == 0
	  && ih->ih_key.u.v1.k_uniqueness == 0)
	{
#ifdef REISERDEBUG
	  printf ("  depth=%d, i=%d/%d\n", depth, i, nr_item);
#endif /* REISERDEBUG */
	  INFO->current_ih   = ih;
	  INFO->current_item = &LEAF[ih->ih_item_location];
	  return 1;
	}
      ih++;
    }
  errnum = ERR_FSYS_CORRUPT;
  return 0;
}

int
reiserfs_read (char *buf, int len)
{
  unsigned int blocksize;
  unsigned int offset;
  unsigned int to_read;
  char *prev_buf = buf;
  
#ifdef REISERDEBUG
  printf ("reiserfs_read: filepos=%d len=%d, offset=%x:%x\n",
	  filepos, len, (__u64) IH_KEY_OFFSET (INFO->current_ih) - 1);
#endif /* REISERDEBUG */
  
  if (INFO->current_ih->ih_key.k_objectid != INFO->fileinfo.k_objectid
      || IH_KEY_OFFSET (INFO->current_ih) > filepos + 1)
    {
      search_stat (INFO->fileinfo.k_dir_id, INFO->fileinfo.k_objectid);
      goto get_next_key;
    }
  
  while (! errnum)
    {
      if (INFO->current_ih->ih_key.k_objectid != INFO->fileinfo.k_objectid)
	break;
      
      offset = filepos - IH_KEY_OFFSET (INFO->current_ih) + 1;
      blocksize = INFO->current_ih->ih_item_len;
      
#ifdef REISERDEBUG
      printf ("  loop: filepos=%d len=%d, offset=%d blocksize=%d\n",
	      filepos, len, offset, blocksize);
#endif /* REISERDEBUG */
      
      if (IH_KEY_ISTYPE(INFO->current_ih, TYPE_DIRECT)
	  && offset < blocksize)
	{
#ifdef REISERDEBUG
	  printf ("direct_read: offset=%d, blocksize=%d\n",
		  offset, blocksize);
#endif /* REISERDEBUG */
	  to_read = blocksize - offset;
	  if (to_read > len)
	    to_read = len;
	  
	  if (disk_read_hook != NULL)
	    {
	      disk_read_func = disk_read_hook;
	      
	      block_read (INFO->blocks[DISK_LEAF_NODE_LEVEL],
			  (INFO->current_item - LEAF + offset), to_read, buf);
	      
	      disk_read_func = NULL;
	    }
	  else
	    memcpy (buf, INFO->current_item + offset, to_read);
	  goto update_buf_len;
	}
      else if (IH_KEY_ISTYPE(INFO->current_ih, TYPE_INDIRECT))
	{
	  blocksize = (blocksize >> 2) << INFO->fullblocksize_shift;
#ifdef REISERDEBUG
	  printf ("indirect_read: offset=%d, blocksize=%d\n",
		  offset, blocksize);
#endif /* REISERDEBUG */
	  
	  while (offset < blocksize)
	    {
	      __u32 blocknr = ((__u32 *) INFO->current_item)
		[offset >> INFO->fullblocksize_shift];
	      int blk_offset = offset & (INFO->blocksize-1);
	      
	      to_read = INFO->blocksize - blk_offset;
	      if (to_read > len)
		to_read = len;
	      
	      disk_read_func = disk_read_hook;
	      
	      /* Journal is only for meta data.  Data blocks can be read
	       * directly without using block_read
	       */
	      devread (blocknr << INFO->blocksize_shift,
		       blk_offset, to_read, buf);
	      
	      disk_read_func = NULL;
	    update_buf_len:
	      len -= to_read;
	      buf += to_read;
	      offset += to_read;
	      filepos += to_read;
	      if (len == 0)
		goto done;
	    }
	}
    get_next_key:
      next_key ();
    }
 done:
  return errnum ? 0 : buf - prev_buf;
}


/* preconditions: reiserfs_mount already executed, therefore 
 *   INFO block is valid
 * returns: 0 if error, nonzero iff we were able to find the file successfully
 * postconditions: on a nonzero return, INFO->fileinfo contains the info
 *   of the file we were trying to look up, filepos is 0 and filemax is 
 *   the size of the file.
 */
int
reiserfs_dir (char *dirname)
{
  struct reiserfs_de_head *de_head;
  char *rest, ch;
  __u32 dir_id, objectid, parent_dir_id = 0, parent_objectid = 0;
#ifndef STAGE1_5
  int do_possibilities = 0;
#endif /* ! STAGE1_5 */
  char linkbuf[PATH_MAX];	/* buffer for following symbolic links */
  int link_count = 0;
  int mode;

  dir_id = REISERFS_ROOT_PARENT_OBJECTID;
  objectid = REISERFS_ROOT_OBJECTID;
  
  while (1)
    {
#ifdef REISERDEBUG
      printf ("dirname=%s\n", dirname);
#endif /* REISERDEBUG */
      
      /* Search for the stat info first. */
      if (! search_stat (dir_id, objectid))
	return 0;
      
#ifdef REISERDEBUG
      printf ("sd_mode=%x sd_size=%d\n", 
	      ((struct stat_data *) INFO->current_item)->sd_mode,
	      ((struct stat_data *) INFO->current_item)->sd_size);
#endif /* REISERDEBUG */
      
      mode = ((struct stat_data *) INFO->current_item)->sd_mode;

      /* If we've got a symbolic link, then chase it. */
      if (S_ISLNK (mode))
	{
	  int len;
	  if (++link_count > MAX_LINK_COUNT)
	    {
	      errnum = ERR_SYMLINK_LOOP;
	      return 0;
	    }

	  /* Get the symlink size. */
	  filemax = ((struct stat_data *) INFO->current_item)->sd_size;

	  /* Find out how long our remaining name is. */
	  len = 0;
	  while (dirname[len] && !isspace (dirname[len]))
	    len++;

	  if (filemax + len > sizeof (linkbuf) - 1)
	    {
	      errnum = ERR_FILELENGTH;
	      return 0;
	    }
 	  
	  /* Copy the remaining name to the end of the symlink data.
	     Note that DIRNAME and LINKBUF may overlap! */
	  grub_memmove (linkbuf + filemax, dirname, len+1);

	  INFO->fileinfo.k_dir_id = dir_id;
	  INFO->fileinfo.k_objectid = objectid;
  	  filepos = 0;
	  if (! next_key ()
	      || reiserfs_read (linkbuf, filemax) != filemax)
	    {
	      if (! errnum)
		errnum = ERR_FSYS_CORRUPT;
	      return 0;
	    }

#ifdef REISERDEBUG
	  printf ("symlink=%s\n", linkbuf);
#endif /* REISERDEBUG */

	  dirname = linkbuf;
	  if (*dirname == '/')
	    {
	      /* It's an absolute link, so look it up in root. */
	      dir_id = REISERFS_ROOT_PARENT_OBJECTID;
	      objectid = REISERFS_ROOT_OBJECTID;
	    }
	  else
	    {
	      /* Relative, so look it up in our parent directory. */
	      dir_id   = parent_dir_id;
	      objectid = parent_objectid;
	    }

	  /* Now lookup the new name. */
	  continue;
	}

      /* if we have a real file (and we're not just printing possibilities),
	 then this is where we want to exit */
      
      if (! *dirname || isspace (*dirname))
	{
	  if (! S_ISREG (mode))
	    {
	      errnum = ERR_BAD_FILETYPE;
	      return 0;
	    }
	  
	  filepos = 0;
	  filemax = ((struct stat_data *) INFO->current_item)->sd_size;
	  
	  /* If this is a new stat data and size is > 4GB set filemax to 
	   * maximum
	   */
	  if (INFO->current_ih->ih_version == ITEM_VERSION_2
	      && ((struct stat_data *) INFO->current_item)->sd_size_hi > 0)
	    filemax = 0xffffffff;
	  
	  INFO->fileinfo.k_dir_id = dir_id;
	  INFO->fileinfo.k_objectid = objectid;
	  return next_key ();
	}
      
      /* continue with the file/directory name interpretation */
      while (*dirname == '/')
	dirname++;
      if (! S_ISDIR (mode))
	{
	  errnum = ERR_BAD_FILETYPE;
	  return 0;
	}
      for (rest = dirname; (ch = *rest) && ! isspace (ch) && ch != '/'; rest++);
      *rest = 0;
      
# ifndef STAGE1_5
      if (print_possibilities && ch != '/')
	do_possibilities = 1;
# endif /* ! STAGE1_5 */
      
      while (1)
	{
	  char *name_end;
	  int num_entries;
	  
	  if (! next_key ())
	    return 0;
#ifdef REISERDEBUG
	  printf ("ih: key %d:%d:%d:%d version:%d\n", 
		  INFO->current_ih->ih_key.k_dir_id, 
		  INFO->current_ih->ih_key.k_objectid, 
		  INFO->current_ih->ih_key.u.v1.k_offset,
		  INFO->current_ih->ih_key.u.v1.k_uniqueness,
		  INFO->current_ih->ih_version);
#endif /* REISERDEBUG */
	  
	  if (INFO->current_ih->ih_key.k_objectid != objectid)
	    break;
	  
	  name_end = INFO->current_item + INFO->current_ih->ih_item_len;
	  de_head = (struct reiserfs_de_head *) INFO->current_item;
	  num_entries = INFO->current_ih->u.ih_entry_count;
	  while (num_entries > 0)
	    {
	      char *filename = INFO->current_item + de_head->deh_location;
	      char  tmp = *name_end;
	      if ((de_head->deh_state & DEH_Visible))
		{
		  int cmp;
		  /* Directory names in ReiserFS are not null
		   * terminated.  We write a temporary 0 behind it.
		   * NOTE: that this may overwrite the first block in
		   * the tree cache.  That doesn't hurt as long as we
		   * don't call next_key () in between.  
		   */
		  *name_end = 0;
		  cmp = substring (dirname, filename);
		  *name_end = tmp;
# ifndef STAGE1_5
		  if (do_possibilities)
		    {
		      if (cmp <= 0)
			{
			  if (print_possibilities > 0)
			    print_possibilities = -print_possibilities;
			  *name_end = 0;
			  print_a_completion (filename);
			  *name_end = tmp;
			}
		    }
		  else
# endif /* ! STAGE1_5 */
		    if (cmp == 0)
		      goto found;
		}
	      /* The beginning of this name marks the end of the next name.
	       */
	      name_end = filename;
	      de_head++;
	      num_entries--;
	    }
	}
      
# ifndef STAGE1_5
      if (print_possibilities < 0)
	return 1;
# endif /* ! STAGE1_5 */
      
      errnum = ERR_FILE_NOT_FOUND;
      *rest = ch;
      return 0;
      
    found:
      
      *rest = ch;
      dirname = rest;

      parent_dir_id = dir_id;
      parent_objectid = objectid;
      dir_id = de_head->deh_dir_id;
      objectid = de_head->deh_objectid;
    }
}

int
reiserfs_embed (int *start_sector, int needed_sectors)
{
  struct reiserfs_super_block super;
  int num_sectors;
  
  if (! devread (REISERFS_DISK_OFFSET_IN_BYTES >> SECTOR_BITS, 0, 
		 sizeof (struct reiserfs_super_block), (char *) &super))
    return 0;
  
  *start_sector = 1; /* reserve first sector for stage1 */
  if ((substring (REISERFS_SUPER_MAGIC_STRING, super.s_magic) <= 0
       || substring (REISER2FS_SUPER_MAGIC_STRING, super.s_magic) <= 0
       || substring (REISER3FS_SUPER_MAGIC_STRING, super.s_magic) <= 0)
      && (/* check that this is not a super block copy inside
	   * the journal log */
	  super.s_journal_block * super.s_blocksize 
	  > REISERFS_DISK_OFFSET_IN_BYTES))
    num_sectors = (REISERFS_DISK_OFFSET_IN_BYTES >> SECTOR_BITS) - 1;
  else
    num_sectors = (REISERFS_OLD_DISK_OFFSET_IN_BYTES >> SECTOR_BITS) - 1;
  
  return (needed_sectors <= num_sectors);
}
#endif /* FSYS_REISERFS */