path: root/fs/ufs/inode.c

/*
 *  linux/fs/ufs/inode.c
 *
 * Copyright (C) 1998
 * Daniel Pirkl <daniel.pirkl@email.cz>
 * Charles University, Faculty of Mathematics and Physics
 *
 *  from
 *
 *  linux/fs/ext2/inode.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)
 *
 *  from
 *
 *  linux/fs/minix/inode.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Goal-directed block allocation by Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller (davem@caip.rutgers.edu), 1995
 */

#include <asm/uaccess.h>
#include <asm/system.h>

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>

#include "ufs_fs.h"
#include "ufs.h"
#include "swab.h"
#include "util.h"

static u64 ufs_frag_map(struct inode *inode, sector_t frag);

static int ufs_block_to_path(struct inode *inode, sector_t i_block, sector_t offsets[4])
{
	struct ufs_sb_private_info *uspi = UFS_SB(inode->i_sb)->s_uspi;
	int ptrs = uspi->s_apb;
	int ptrs_bits = uspi->s_apbshift;
	const long direct_blocks = UFS_NDADDR,
		indirect_blocks = ptrs,
		double_blocks = (1 << (ptrs_bits * 2));
	int n = 0;


	UFSD("ptrs=uspi->s_apb = %d,double_blocks=%ld \n",ptrs,double_blocks);
	if (i_block < direct_blocks) {
		offsets[n++] = i_block;
	} else if ((i_block -= direct_blocks) < indirect_blocks) {
		offsets[n++] = UFS_IND_BLOCK;
		offsets[n++] = i_block;
	} else if ((i_block -= indirect_blocks) < double_blocks) {
		offsets[n++] = UFS_DIND_BLOCK;
		offsets[n++] = i_block >> ptrs_bits;
		offsets[n++] = i_block & (ptrs - 1);
	} else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
		offsets[n++] = UFS_TIND_BLOCK;
		offsets[n++] = i_block >> (ptrs_bits * 2);
		offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
		offsets[n++] = i_block & (ptrs - 1);
	} else {
		ufs_warning(inode->i_sb, "ufs_block_to_path", "block > big");
	}
	return n;
}

/*
 * Returns the location of the fragment from
 * the begining of the filesystem.
 */

static u64 ufs_frag_map(struct inode *inode, sector_t frag)
{
	struct ufs_inode_info *ufsi = UFS_I(inode);
	struct super_block *sb = inode->i_sb;
	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
	u64 mask = (u64) uspi->s_apbmask>>uspi->s_fpbshift;
	int shift = uspi->s_apbshift-uspi->s_fpbshift;
	sector_t offsets[4], *p;
	int depth = ufs_block_to_path(inode, frag >> uspi->s_fpbshift, offsets);
	u64  ret = 0L;
	__fs32 block;
	__fs64 u2_block = 0L;
	unsigned flags = UFS_SB(sb)->s_flags;
	u64 temp = 0L;

	UFSD(": frag = %llu  depth = %d\n", (unsigned long long)frag, depth);
	UFSD(": uspi->s_fpbshift = %d ,uspi->s_apbmask = %x, mask=%llx\n",
		uspi->s_fpbshift, uspi->s_apbmask,
		(unsigned long long)mask);

	if (depth == 0)
		return 0;

	p = offsets;

	lock_kernel();
	if ((flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2)
		goto ufs2;

	block = ufsi->i_u1.i_data[*p++];
	if (!block)
		goto out;
	while (--depth) {
		struct buffer_head *bh;
		sector_t n = *p++;

		bh = sb_bread(sb, uspi->s_sbbase + fs32_to_cpu(sb, block)+(n>>shift));
		if (!bh)
			goto out;
		block = ((__fs32 *) bh->b_data)[n & mask];
		brelse (bh);
		if (!block)
			goto out;
	}
	ret = (u64) (uspi->s_sbbase + fs32_to_cpu(sb, block) + (frag & uspi->s_fpbmask));
	goto out;
ufs2:
	u2_block = ufsi->i_u1.u2_i_data[*p++];
	if (!u2_block)