path: root/fs/reiserfs/bitmap.c

/*
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */
/* Reiserfs block (de)allocator, bitmap-based. */

#include <linux/config.h>
#include <linux/time.h>
#include <linux/reiserfs_fs.h>
#include <linux/errno.h>
#include <linux/buffer_head.h>
#include <linux/kernel.h>
#include <linux/pagemap.h>
#include <linux/reiserfs_fs_sb.h>
#include <linux/reiserfs_fs_i.h>
#include <linux/quotaops.h>

#define PREALLOCATION_SIZE 9

/* different reiserfs block allocator options */

#define SB_ALLOC_OPTS(s) (REISERFS_SB(s)->s_alloc_options.bits)

#define  _ALLOC_concentrating_formatted_nodes 0
#define  _ALLOC_displacing_large_files 1
#define  _ALLOC_displacing_new_packing_localities 2
#define  _ALLOC_old_hashed_relocation 3
#define  _ALLOC_new_hashed_relocation 4
#define  _ALLOC_skip_busy 5
#define  _ALLOC_displace_based_on_dirid 6
#define  _ALLOC_hashed_formatted_nodes 7
#define  _ALLOC_old_way 8
#define  _ALLOC_hundredth_slices 9
#define  _ALLOC_dirid_groups 10
#define  _ALLOC_oid_groups 11
#define  _ALLOC_packing_groups 12

#define  concentrating_formatted_nodes(s)	test_bit(_ALLOC_concentrating_formatted_nodes, &SB_ALLOC_OPTS(s))
#define  displacing_large_files(s)		test_bit(_ALLOC_displacing_large_files, &SB_ALLOC_OPTS(s))
#define  displacing_new_packing_localities(s)	test_bit(_ALLOC_displacing_new_packing_localities, &SB_ALLOC_OPTS(s))

#define SET_OPTION(optname) \
   do { \
        reiserfs_warning(s, "reiserfs: option \"%s\" is set", #optname); \
        set_bit(_ALLOC_ ## optname , &SB_ALLOC_OPTS(s)); \
    } while(0)
#define TEST_OPTION(optname, s) \
    test_bit(_ALLOC_ ## optname , &SB_ALLOC_OPTS(s))

static inline void get_bit_address(struct super_block *s,
				   b_blocknr_t block, int *bmap_nr, int *offset)
{
	/* It is in the bitmap block number equal to the block
	 * number divided by the number of bits in a block. */
	*bmap_nr = block / (s->s_blocksize << 3);
	/* Within that bitmap block it is located at bit offset *offset. */
	*offset = block & ((s->s_blocksize << 3) - 1);
	return;
}

#ifdef CONFIG_REISERFS_CHECK
int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value)
{
	int i, j;

	if (block == 0 || block >= SB_BLOCK_COUNT(s)) {
		reiserfs_warning(s,
				 "vs-4010: is_reusable: block number is out of range %lu (%u)",
				 block, SB_BLOCK_COUNT(s));
		return 0;
	}

	/* it can't be one of the bitmap blocks */
	for (i = 0; i < SB_BMAP_NR(s); i++)
		if (block == SB_AP_BITMAP(s)[i].bh->b_blocknr) {
			reiserfs_warning(s, "vs: 4020: is_reusable: "
					 "bitmap block %lu(%u) can't be freed or reused",
					 block, SB_BMAP_NR(s));
			return 0;
		}

	get_bit_address(s, block, &i, &j);

	if (i >= SB_BMAP_NR(s)) {
		reiserfs_warning(s,
				 "vs-4030: is_reusable: there is no so many bitmap blocks: "
				 "block=%lu, bitmap_nr=%d", block, i);
		return 0;
	}

	if ((bit_value == 0 &&
	     reiserfs_test_le_bit(j, SB_AP_BITMAP(s)[i].bh->b_data)) ||
	    (bit_value == 1 &&
	     reiserfs_test_le_bit(j, SB_AP_BITMAP(s)[i].bh->b_data) == 0)) {
		reiserfs_warning(s,
				 "vs-4040: is_reusable: corresponding bit of block %lu does not "
				 "match required value (i==%d, j==%d) test_bit==%d",
				 block, i, j, reiserfs_test_le_bit(j,