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 <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/buffer_head.h>
#include <linux/writeback.h>

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

static int ufs_block_to_path(struct inode *inode, sector_t i_block, unsigned 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;
}

typedef struct {
	void	*p;
	union {
		__fs32	key32;
		__fs64	key64;
	};
	struct buffer_head *bh;
} Indirect;

static inline int grow_chain32(struct ufs_inode_info *ufsi,
			       struct buffer_head *bh, __fs32 *v,
			       Indirect *from, Indirect *to)
{
	Indirect *p;
	unsigned seq;
	to->bh = bh;
	do {
		seq = read_seqbegin(&ufsi->meta_lock);
		to->key32 = *(__fs32 *)(to->p = v);
		for (p = from; p <= to && p->key32 == *(__fs32 *)p->p; p++)
			;
	} while (read_seqretry(&ufsi->meta_lock, seq));
	return (p > to);
}

static inline int grow_chain64(struct ufs_inode_info *ufsi,
			       struct buffer_head *bh, __fs64 *v,
			       Indirect *from, Indirect *to)
{
	Indirect *p;
	unsigned seq;
	to->bh = bh;
	do {
		seq = read_seqbegin(&ufsi->meta_lock);
		to