inode.c

UnixBSD、SunOs、FreeBSD、NetBSD、OpenBSD和NeXTStep文件系统源代码

/*
 *  linux/fs/ufs/inode.c
 *
 * Copyright (C) 1998
 * Daniel Pirkl <[e-mail]>
 * Charles University, Faculty of Mathematics and Physics
 *
 *  from
 *
 *  linux/fs/ext2/inode.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card ([e-mail])
 * 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 ([e-mail]), 1993
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller ([e-mail]), 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 < 0) {
		ufs_warning(inode->i_sb, "ufs_block_to_path", "block < 0");
	} else 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)
		goto out;


	while (--depth) {
		struct buffer_head *bh;
		sector_t n = *p++;


		temp = (u64)(uspi->s_sbbase) + fs64_to_cpu(sb, u2_block);
		bh = sb_bread(sb, temp +(u64) (n>>shift));
		if (!bh)
			goto out;
		u2_block = ((__fs64 *)bh->b_data)[n & mask];
		brelse(bh);
		if (!u2_block)
			goto out;
	}
	temp = (u64)uspi->s_sbbase + fs64_to_cpu(sb, u2_block);
	ret = temp + (u64) (frag & uspi->s_fpbmask);

out:
	unlock_kernel();
	return ret;
}

/**
 * ufs_inode_getfrag() - allocate new fragment(s)
 * @inode - pointer to inode
 * @fragment - number of `fragment' which hold pointer
 *   to new allocated fragment(s)
 * @new_fragment - number of new allocated fragment(s)
 * @required - how many fragment(s) we require
 * @err - we set it if something wrong
 * @phys - pointer to where we save physical number of new allocated fragments,
 *   NULL if we allocate not data(indirect blocks for example).
 * @new - we set it if we allocate new block
 * @locked_page - for ufs_new_fragments()
 */
static struct buffer_head *
ufs_inode_getfrag(struct inode *inode, u64 fragment,
		  sector_t new_fragment, unsigned int required, int *err,
		  long *phys, int *new, struct page *locked_page)
{
	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;
	struct buffer_head * result;
	unsigned blockoff, lastblockoff;
	u64 tmp, goal, lastfrag, block, lastblock;
	void *p, *p2;

	UFSD("ENTER, ino %lu, fragment %llu, new_fragment %llu, required %u, "
	     "metadata %d\n", inode->i_ino, (unsigned long long)fragment,
	     (unsigned long long)new_fragment, required, !phys);

        /* TODO : to be done for write support
        if ( (flags & UFS_TYPE_MASK) == UFS_TYPE_UFS2)
             goto ufs2;
         */

	block = ufs_fragstoblks (fragment);
	blockoff = ufs_fragnum (fragment);
	p = ufs_get_direct_data_ptr(uspi, ufsi, block);

	goal = 0;

repeat:
	tmp = ufs_data_ptr_to_cpu(sb, p);

	lastfrag = ufsi->i_lastfrag;
	if (tmp && fragment < lastfrag) {
		if (!phys) {
			result = sb_getblk(sb, uspi->s_sbbase + tmp + blockoff);
			if (tmp == ufs_data_ptr_to_cpu(sb, p)) {
				UFSD("EXIT, result %llu\n",
				     (unsigned long long)tmp + blockoff);
				return result;
			}
			brelse (result);
			goto repeat;
		} else {
			*phys = uspi->s_sbbase + tmp + blockoff;
			return NULL;
		}
	}

	lastblock = ufs_fragstoblks (lastfrag);
	lastblockoff = ufs_fragnum (lastfrag);
	/*
	 * We will extend file into new block beyond last allocated block
	 */
	if (lastblock < block) {
		/*
		 * We must reallocate last allocated block
		 */
		if (lastblockoff) {
			p2 = ufs_get_direct_data_ptr(uspi, ufsi, lastblock);
			tmp = ufs_new_fragments(inode, p2, lastfrag,
						ufs_data_ptr_to_cpu(sb, p2),
						uspi->s_fpb - lastblockoff,
						err, locked_page);
			if (!tmp) {
				if (lastfrag != ufsi->i_lastfrag)
					goto repeat;
				else
					return NULL;
			}
			lastfrag = ufsi->i_lastfrag;
			
		}
		tmp = ufs_data_ptr_to_cpu(sb,
					 ufs_get_direct_data_ptr(uspi, ufsi,
								 lastblock));
		if (tmp)
			goal = tmp + uspi->s_fpb;
		tmp = ufs_new_fragments (inode, p, fragment - blockoff, 
					 goal, required + blockoff,
					 err,
					 phys != NULL ? locked_page : NULL);
	} else if (lastblock == block) {
	/*
	 * We will extend last allocated block
	 */
		tmp = ufs_new_fragments(inode, p, fragment -
					(blockoff - lastblockoff),
					ufs_data_ptr_to_cpu(sb, p),
					required +  (blockoff - lastblockoff),
					err, phys != NULL ? locked_page : NULL);
	} else /* (lastblock > block) */ {
	/*
	 * We will allocate new block before last allocated block
	 */
		if (block) {
			tmp = ufs_data_ptr_to_cpu(sb,
						 ufs_get_direct_data_ptr(uspi, ufsi, block - 1));
			if (tmp)
				goal = tmp + uspi->s_fpb;
		}
		tmp = ufs_new_fragments(inode, p, fragment - blockoff,
					goal, uspi->s_fpb, err,
					phys != NULL ? locked_page : NULL);
	}
	if (!tmp) {
		if ((!blockoff && ufs_data_ptr_to_cpu(sb, p)) ||
		    (blockoff && lastfrag != ufsi->i_lastfrag))
			goto repeat;
		*err = -ENOSPC;
		return NULL;
	}

	if (!phys) {
		result = sb_getblk(sb, uspi->s_sbbase + tmp + blockoff);
	} else {
		*phys = uspi->s_sbbase + tmp + blockoff;
		result = NULL;
		*err = 0;
		*new = 1;
	}

	inode->i_ctime = CURRENT_TIME_SEC;
	if (IS_SYNC(inode))
		ufs_sync_inode (inode);
	mark_inode_dirty(inode);
	UFSD("EXIT, result %llu\n", (unsigned long long)tmp + blockoff);
	return result;

     /* This part : To be implemented ....
        Required only for writing, not required for READ-ONLY.
ufs2:

	u2_block = ufs_fragstoblks(fragment);
	u2_blockoff = ufs_fragnum(fragment);
	p = ufsi->i_u1.u2_i_data + block;
	goal = 0;

repeat2:
	tmp = fs32_to_cpu(sb, *p);
	lastfrag = ufsi->i_lastfrag;

     */
}

/**
 * ufs_inode_getblock() - allocate new block
 * @inode - pointer to inode
 * @bh - pointer to block which hold "pointer" to new allocated block
 * @fragment - number of `fragment' which hold pointer
 *   to new allocated block
 * @new_fragment - number of new allocated fragment
 *  (block will hold this fragment and also uspi->s_fpb-1)
 * @err - see ufs_inode_getfrag()
 * @phys - see ufs_inode_getfrag()
 * @new - see ufs_inode_getfrag()
 * @locked_page - see ufs_inode_getfrag()
 */
static struct buffer_head *
ufs_inode_getblock(struct inode *inode, struct buffer_head *bh,
		  u64 fragment, sector_t new_fragment, int *err,
		  long *phys, int *new, struct page *locked_page)
{
	struct super_block *sb = inode->i_sb;
	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
	struct buffer_head * result;
	unsigned blockoff;
	u64 tmp, goal, block;
	void *p;

	block = ufs_fragstoblks (fragment);
	blockoff = ufs_fragnum (fragment);

	UFSD("ENTER, ino %lu, fragment %llu, new_fragment %llu, metadata %d\n",
	     inode->i_ino, (unsigned long long)fragment,
	     (unsigned long long)new_fragment, !phys);

	result = NULL;
	if (!bh)
		goto out;
	if (!buffer_uptodate(bh)) {
		ll_rw_block (READ, 1, &bh);
		wait_on_buffer (bh);
		if (!buffer_uptodate(bh))
			goto out;
	}
	if (uspi->fs_magic == UFS2_MAGIC)
		p = (__fs64 *)bh->b_data + block;
	else
		p = (__fs32 *)bh->b_data + block;
repeat:
	tmp = ufs_data_ptr_to_cpu(sb, p);
	if (tmp) {
		if (!phys) {
			result = sb_getblk(sb, uspi->s_sbbase + tmp + blockoff);
			if (tmp == ufs_data_ptr_to_cpu(sb, p))
				goto out;
			brelse (result);
			goto repeat;
		} else {
			*phys = uspi->s_sbbase + tmp + blockoff;
			goto out;
		}
	}

	if (block && (uspi->fs_magic == UFS2_MAGIC ?
		      (tmp = fs64_to_cpu(sb, ((__fs64 *)bh->b_data)[block-1])) :
		      (tmp = fs32_to_cpu(sb, ((__fs32 *)bh->b_data)[block-1]))))
		goal = tmp + uspi->s_fpb;
	else
		goal = bh->b_blocknr + uspi->s_fpb;
	tmp = ufs_new_fragments(inode, p, ufs_blknum(new_fragment), goal,
				uspi->s_fpb, err, locked_page);
	if (!tmp) {
		if (ufs_data_ptr_to_cpu(sb, p))
			goto repeat;
		goto out;
	}		


	if (!phys) {
		result = sb_getblk(sb, uspi->s_sbbase + tmp + blockoff);
	} else {
		*phys = uspi->s_sbbase + tmp + blockoff;
		*new = 1;
	}

	mark_buffer_dirty(bh);
	if (IS_SYNC(inode))
		sync_dirty_buffer(bh);
	inode->i_ctime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);
	UFSD("result %llu\n", (unsigned long long)tmp + blockoff);
out:
	brelse (bh);
	UFSD("EXIT\n");
	return result;
}

/**
 * ufs_getfrag_bloc() - `get_block_t' function, interface between UFS and
 * readpage, writepage and so on
 */

int ufs_getfrag_block(struct inode *inode, sector_t fragment, struct buffer_head *bh_result, int create)
{
	struct super_block * sb = inode->i_sb;
	struct ufs_sb_private_info * uspi = UFS_SB(sb)->s_uspi;
	struct buffer_head * bh;
	int ret, err, new;
	unsigned long ptr,phys;
	u64 phys64 = 0;
	
	if (!create) {
		phys64 = ufs_frag_map(inode, fragment);
		UFSD("phys64 = %llu\n", (unsigned long long)phys64);
		if (phys64)
			map_bh(bh_result, sb, phys64);
		return 0;
	}

        /* This code entered only while writing ....? */

	err = -EIO;
	new = 0;
	ret = 0;
	bh = NULL;

	lock_kernel();

	UFSD("ENTER, ino %lu, fragment %llu\n", inode->i_ino, (unsigned long long)fragment);
	if (fragment < 0)
		goto abort_negative;
	if (fragment >
	    ((UFS_NDADDR + uspi->s_apb + uspi->s_2apb + uspi->s_3apb)
	     << uspi->s_fpbshift))
		goto abort_too_big;

	err = 0;
	ptr = fragment;
	  
	/*
	 * ok, these macros clean the logic up a bit and make
	 * it much more readable:
	 */
#define GET_INODE_DATABLOCK(x) \
	ufs_inode_getfrag(inode, x, fragment, 1, &err, &phys, &new,\
			  bh_result->b_page)
#define GET_INODE_PTR(x) \
	ufs_inode_getfrag(inode, x, fragment, uspi->s_fpb, &err, NULL, NULL,\
			  bh_result->b_page)
#define GET_INDIRECT_DATABLOCK(x) \
	ufs_inode_getblock(inode, bh, x, fragment,	\
			  &err, &phys, &new, bh_result->b_page)
#define GET_INDIRECT_PTR(x) \
	ufs_inode_getblock(inode, bh, x, fragment,	\
			  &err, NULL, NULL, NULL)

	if (ptr < UFS_NDIR_FRAGMENT) {