/* * linux/fs/ext4/bitmap.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) */ #include <linux/buffer_head.h> #include <linux/jbd2.h> #include "ext4.h" #ifdef EXT4FS_DEBUG static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0}; unsigned int ext4_count_free(struct buffer_head *map, unsigned int numchars) { unsigned int i, sum = 0; if (!map) return 0; for (i = 0; i < numchars; i++) sum += nibblemap[map->b_data[i] & 0xf] + nibblemap[(map->b_data[i] >> 4) & 0xf]; return sum; } #endif /* EXT4FS_DEBUG */