Logo Search packages:      
Sourcecode: yaboot version File versions  Download package

dblist.c

/*
 * dblist.c -- directory block list functions
 * 
 * Copyright 1997 by Theodore Ts'o
 * 
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 * 
 */

#include <stdio.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include <time.h>

#include "ext2_fs.h"
#include "ext2fsP.h"

static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b);

/*
 * Returns the number of directories in the filesystem as reported by
 * the group descriptors.  Of course, the group descriptors could be
 * wrong!
 */
errcode_t ext2fs_get_num_dirs(ext2_filsys fs, ext2_ino_t *ret_num_dirs)
{
      dgrp_t      i;
      ext2_ino_t  num_dirs, max_dirs;

      EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
      
      num_dirs = 0;
      max_dirs = fs->super->s_inodes_per_group;
      for (i = 0; i < fs->group_desc_count; i++) {
            if (fs->group_desc[i].bg_used_dirs_count > max_dirs)
                  num_dirs += max_dirs / 8;
            else
                  num_dirs += fs->group_desc[i].bg_used_dirs_count;
      }
      if (num_dirs > fs->super->s_inodes_count)
            num_dirs = fs->super->s_inodes_count;

      *ret_num_dirs = num_dirs;

      return 0;
}

/*
 * helper function for making a new directory block list (for
 * initialize and copy).
 */
static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size, ext2_ino_t count,
                       struct ext2_db_entry *list,
                       ext2_dblist *ret_dblist)
{
      ext2_dblist dblist;
      errcode_t   retval;
      size_t            len;

      EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

      if ((ret_dblist == 0) && fs->dblist &&
          (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
            return 0;

      retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist),
                        (void **) &dblist);
      if (retval)
            return retval;
      memset(dblist, 0, sizeof(struct ext2_struct_dblist));

      dblist->magic = EXT2_ET_MAGIC_DBLIST;
      dblist->fs = fs;
      if (size)
            dblist->size = size;
      else {
            retval = ext2fs_get_num_dirs(fs, &dblist->size);
            if (retval)
                  goto cleanup;
            dblist->size = (dblist->size * 2) + 12;
      }
      len = (size_t) sizeof(struct ext2_db_entry) * dblist->size;
      dblist->count = count;
      retval = ext2fs_get_mem(len, (void **) &dblist->list);
      if (retval)
            goto cleanup;
      
      if (list)
            memcpy(dblist->list, list, len);
      else
            memset(dblist->list, 0, len);
      if (ret_dblist)
            *ret_dblist = dblist;
      else
            fs->dblist = dblist;
      return 0;
cleanup:
      if (dblist)
            ext2fs_free_mem((void **) &dblist);
      return retval;
}

/*
 * Initialize a directory block list
 */
errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
{
      ext2_dblist dblist;
      errcode_t   retval;

      retval = make_dblist(fs, 0, 0, 0, &dblist);
      if (retval)
            return retval;

      dblist->sorted = 1;
      if (ret_dblist)
            *ret_dblist = dblist;
      else
            fs->dblist = dblist;

      return 0;
}

/*
 * Copy a directory block list
 */
errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
{
      ext2_dblist dblist;
      errcode_t   retval;

      retval = make_dblist(src->fs, src->size, src->count, src->list,
                       &dblist);
      if (retval)
            return retval;
      dblist->sorted = src->sorted;
      *dest = dblist;
      return 0;
}

/*
 * Close a directory block list
 *
 * (moved to closefs.c)
 */


/*
 * Add a directory block to the directory block list
 */
errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
                         int blockcnt)
{
      struct ext2_db_entry    *new_entry;
      errcode_t         retval;
      unsigned long           old_size;
      
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);

      if (dblist->count >= dblist->size) {
            old_size = dblist->size * sizeof(struct ext2_db_entry);
            dblist->size += 100;
            retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
                                 sizeof(struct ext2_db_entry),
                                 (void **) &dblist->list);
            if (retval) {
                  dblist->size -= 100;
                  return retval;
            }
      }
      new_entry = dblist->list + ( (int) dblist->count++);
      new_entry->blk = blk;
      new_entry->ino = ino;
      new_entry->blockcnt = blockcnt;

      dblist->sorted = 0;

      return 0;
}

/*
 * Change the directory block to the directory block list
 */
errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
                         int blockcnt)
{
      dgrp_t                  i;
      
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);

      for (i=0; i < dblist->count; i++) {
            if ((dblist->list[i].ino != ino) ||
                (dblist->list[i].blockcnt != blockcnt))
                  continue;
            dblist->list[i].blk = blk;
            dblist->sorted = 0;
            return 0;
      }
      return EXT2_ET_DB_NOT_FOUND;
}

/*
 * This function iterates over the directory block list
 */
errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
                        int (*func)(ext2_filsys fs,
                                  struct ext2_db_entry *db_info,
                                  void    *priv_data),
                        void *priv_data)
{
      ext2_ino_t  i;
      int         ret;
      
      EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);

      if (!dblist->sorted) {
            qsort(dblist->list, (size_t) dblist->count,
                  sizeof(struct ext2_db_entry), dir_block_cmp);
            dblist->sorted = 1;
      }
      for (i=0; i < dblist->count; i++) {
            ret = (*func)(dblist->fs, &dblist->list[(int)i], priv_data);
            if (ret & DBLIST_ABORT)
                  return 0;
      }
      return 0;
}


static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b)
{
      const struct ext2_db_entry *db_a =
            (const struct ext2_db_entry *) a;
      const struct ext2_db_entry *db_b =
            (const struct ext2_db_entry *) b;

      if (db_a->blk != db_b->blk)
            return (int) (db_a->blk - db_b->blk);
      
      if (db_a->ino != db_b->ino)
            return (int) (db_a->ino - db_b->ino);

      return (int) (db_a->blockcnt - db_b->blockcnt);
}

int ext2fs_dblist_count(ext2_dblist dblist)
{
      return (int) dblist->count;
}

Generated by  Doxygen 1.6.0   Back to index