fs/freevxfs/vxfs_bmap.c - kernel/mindspeed - Git at Google

 /*
  * Copyright (c) 2000-2001 Christoph Hellwig.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions, and the following disclaimer,
  *    without modification.
  * 2. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * Alternatively, this software may be distributed under the terms of the
  * GNU General Public License ("GPL").
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */

 /*
  * Veritas filesystem driver - filesystem to disk block mapping.
  */
 #include <linux/fs.h>
 #include <linux/buffer_head.h>
 #include <linux/kernel.h>

 #include "vxfs.h"
 #include "vxfs_inode.h"
 #include "vxfs_extern.h"


 #ifdef DIAGNOSTIC
 static void
 vxfs_typdump(struct vxfs_typed *typ)
 {
 	printk(KERN_DEBUG "type=%Lu ", typ->vt_hdr >> VXFS_TYPED_TYPESHIFT);
 	printk("offset=%Lx ", typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
 	printk("block=%x ", typ->vt_block);
 	printk("size=%x\n", typ->vt_size);
 }
 #endif

 /**
  * vxfs_bmap_ext4 - do bmap for ext4 extents
  * @ip:		pointer to the inode we do bmap for
  * @iblock:	logical block.
  *
  * Description:
  *   vxfs_bmap_ext4 performs the bmap operation for inodes with
  *   ext4-style extents (which are much like the traditional UNIX
  *   inode organisation).
  *
  * Returns:
  *   The physical block number on success, else Zero.
  */
 static daddr_t
 vxfs_bmap_ext4(struct inode *ip, long bn)
 {
 	struct super_block *sb = ip->i_sb;
 	struct vxfs_inode_info *vip = VXFS_INO(ip);
 	unsigned long bsize = sb->s_blocksize;
 	u32 indsize = vip->vii_ext4.ve4_indsize;
 	int i;

 	if (indsize > sb->s_blocksize)
 		goto fail_size;

 	for (i = 0; i < VXFS_NDADDR; i++) {
 		struct direct *d = vip->vii_ext4.ve4_direct + i;
 		if (bn >= 0 && bn < d->size)
 			return (bn + d->extent);
 		bn -= d->size;
 	}

 	if ((bn / (indsize * indsize * bsize / 4)) == 0) {
 		struct buffer_head *buf;
 		daddr_t	bno;
 		u32 *indir;

 		buf = sb_bread(sb, vip->vii_ext4.ve4_indir[0]);
 		if (!buf || !buffer_mapped(buf))
 			goto fail_buf;

 		indir = (u32 *)buf->b_data;
 		bno = indir[(bn/indsize) % (indsize*bn)] + (bn%indsize);

 		brelse(buf);
 		return bno;
 	} else
 		printk(KERN_WARNING "no matching indir?");

 	return 0;

 fail_size:
 	printk("vxfs: indirect extent too big!\n");
 fail_buf:
 	return 0;
 }

 /**
  * vxfs_bmap_indir - recursion for vxfs_bmap_typed
  * @ip:		pointer to the inode we do bmap for
  * @indir:	indirect block we start reading at
  * @size:	size of the typed area to search
  * @block:	partially result from further searches
  *
  * Description:
  *   vxfs_bmap_indir reads a &struct vxfs_typed at @indir
  *   and performs the type-defined action.
  *
  * Return Value:
  *   The physical block number on success, else Zero.
  *
  * Note:
  *   Kernelstack is rare.  Unrecurse?
  */
 static daddr_t
 vxfs_bmap_indir(struct inode *ip, long indir, int size, long block)
 {
 	struct buffer_head		*bp = NULL;
 	daddr_t				pblock = 0;
 	int				i;

 	for (i = 0; i < size * VXFS_TYPED_PER_BLOCK(ip->i_sb); i++) {
 		struct vxfs_typed	*typ;
 		int64_t			off;

 		bp = sb_bread(ip->i_sb,
 				indir + (i / VXFS_TYPED_PER_BLOCK(ip->i_sb)));
 		if (!bp || !buffer_mapped(bp))
 			return 0;

 		typ = ((struct vxfs_typed *)bp->b_data) +
 			(i % VXFS_TYPED_PER_BLOCK(ip->i_sb));
 		off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);

 		if (block < off) {
 			brelse(bp);
 			continue;
 		}

 		switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
 		case VXFS_TYPED_INDIRECT:
 			pblock = vxfs_bmap_indir(ip, typ->vt_block,
 					typ->vt_size, block - off);
 			if (pblock == -2)
 				break;
 			goto out;
 		case VXFS_TYPED_DATA:
 			if ((block - off) >= typ->vt_size)
 				break;
 			pblock = (typ->vt_block + block - off);
 			goto out;
 		case VXFS_TYPED_INDIRECT_DEV4:
 		case VXFS_TYPED_DATA_DEV4: {
 			struct vxfs_typed_dev4	*typ4 =
 				(struct vxfs_typed_dev4 *)typ;

 			printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
 			printk(KERN_INFO "block: %Lu\tsize: %Ld\tdev: %d\n",
 			       (unsigned long long) typ4->vd4_block,
 			       (unsigned long long) typ4->vd4_size,
 			       typ4->vd4_dev);
 			goto fail;
 		}
 		default:
 			BUG();
 		}
 		brelse(bp);
 	}

 fail:
 	pblock = 0;
 out:
 	brelse(bp);
 	return (pblock);
 }

 /**
  * vxfs_bmap_typed - bmap for typed extents
  * @ip:		pointer to the inode we do bmap for
  * @iblock:	logical block
  *
  * Description:
  *   Performs the bmap operation for typed extents.
  *
  * Return Value:
  *   The physical block number on success, else Zero.
  */
 static daddr_t
 vxfs_bmap_typed(struct inode *ip, long iblock)
 {
 	struct vxfs_inode_info		*vip = VXFS_INO(ip);
 	daddr_t				pblock = 0;
 	int				i;

 	for (i = 0; i < VXFS_NTYPED; i++) {
 		struct vxfs_typed	*typ = vip->vii_org.typed + i;
 		int64_t			off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);

 #ifdef DIAGNOSTIC
 		vxfs_typdump(typ);
 #endif
 		if (iblock < off)
 			continue;
 		switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
 		case VXFS_TYPED_INDIRECT:
 			pblock = vxfs_bmap_indir(ip, typ->vt_block,
 					typ->vt_size, iblock - off);
 			if (pblock == -2)
 				break;
 			return (pblock);
 		case VXFS_TYPED_DATA:
 			if ((iblock - off) < typ->vt_size)
 				return (typ->vt_block + iblock - off);
 			break;
 		case VXFS_TYPED_INDIRECT_DEV4:
 		case VXFS_TYPED_DATA_DEV4: {
 			struct vxfs_typed_dev4	*typ4 =
 				(struct vxfs_typed_dev4 *)typ;

 			printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
 			printk(KERN_INFO "block: %Lu\tsize: %Ld\tdev: %d\n",
 			       (unsigned long long) typ4->vd4_block,
 			       (unsigned long long) typ4->vd4_size,
 			       typ4->vd4_dev);
 			return 0;
 		}
 		default:
 			BUG();
 		}
 	}

 	return 0;
 }

 /**
  * vxfs_bmap1 - vxfs-internal bmap operation
  * @ip:			pointer to the inode we do bmap for
  * @iblock:		logical block
  *
  * Description:
  *   vxfs_bmap1 perfoms a logical to physical block mapping
  *   for vxfs-internal purposes.
  *
  * Return Value:
  *   The physical block number on success, else Zero.
  */
 daddr_t
 vxfs_bmap1(struct inode *ip, long iblock)
 {
 	struct vxfs_inode_info		*vip = VXFS_INO(ip);

 	if (VXFS_ISEXT4(vip))
 		return vxfs_bmap_ext4(ip, iblock);
 	if (VXFS_ISTYPED(vip))
 		return vxfs_bmap_typed(ip, iblock);
 	if (VXFS_ISNONE(vip))
 		goto unsupp;
 	if (VXFS_ISIMMED(vip))
 		goto unsupp;

 	printk(KERN_WARNING "vxfs: inode %ld has no valid orgtype (%x)\n",
 			ip->i_ino, vip->vii_orgtype);
 	BUG();

 unsupp:
 	printk(KERN_WARNING "vxfs: inode %ld has an unsupported orgtype (%x)\n",
 			ip->i_ino, vip->vii_orgtype);
 	return 0;
 }
	/*
	* Copyright (c) 2000-2001 Christoph Hellwig.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions, and the following disclaimer,
	* without modification.
	* 2. The name of the author may not be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* Alternatively, this software may be distributed under the terms of the
	* GNU General Public License ("GPL").
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
	* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*/

	/*
	* Veritas filesystem driver - filesystem to disk block mapping.
	*/
	#include <linux/fs.h>
	#include <linux/buffer_head.h>
	#include <linux/kernel.h>

	#include "vxfs.h"
	#include "vxfs_inode.h"
	#include "vxfs_extern.h"


	#ifdef DIAGNOSTIC
	static void
	vxfs_typdump(struct vxfs_typed *typ)
	{
	printk(KERN_DEBUG "type=%Lu ", typ->vt_hdr >> VXFS_TYPED_TYPESHIFT);
	printk("offset=%Lx ", typ->vt_hdr & VXFS_TYPED_OFFSETMASK);
	printk("block=%x ", typ->vt_block);
	printk("size=%x\n", typ->vt_size);
	}
	#endif

	/**
	* vxfs_bmap_ext4 - do bmap for ext4 extents
	* @ip: pointer to the inode we do bmap for
	* @iblock: logical block.
	*
	* Description:
	* vxfs_bmap_ext4 performs the bmap operation for inodes with
	* ext4-style extents (which are much like the traditional UNIX
	* inode organisation).
	*
	* Returns:
	* The physical block number on success, else Zero.
	*/
	static daddr_t
	vxfs_bmap_ext4(struct inode *ip, long bn)
	{
	struct super_block *sb = ip->i_sb;
	struct vxfs_inode_info *vip = VXFS_INO(ip);
	unsigned long bsize = sb->s_blocksize;
	u32 indsize = vip->vii_ext4.ve4_indsize;
	int i;

	if (indsize > sb->s_blocksize)
	goto fail_size;

	for (i = 0; i < VXFS_NDADDR; i++) {
	struct direct *d = vip->vii_ext4.ve4_direct + i;
	if (bn >= 0 && bn < d->size)
	return (bn + d->extent);
	bn -= d->size;
	}

	if ((bn / (indsize * indsize * bsize / 4)) == 0) {
	struct buffer_head *buf;
	daddr_t bno;
	u32 *indir;

	buf = sb_bread(sb, vip->vii_ext4.ve4_indir[0]);
	if (!buf \|\| !buffer_mapped(buf))
	goto fail_buf;

	indir = (u32 *)buf->b_data;
	bno = indir[(bn/indsize) % (indsize*bn)] + (bn%indsize);

	brelse(buf);
	return bno;
	} else
	printk(KERN_WARNING "no matching indir?");

	return 0;

	fail_size:
	printk("vxfs: indirect extent too big!\n");
	fail_buf:
	return 0;
	}

	/**
	* vxfs_bmap_indir - recursion for vxfs_bmap_typed
	* @ip: pointer to the inode we do bmap for
	* @indir: indirect block we start reading at
	* @size: size of the typed area to search
	* @block: partially result from further searches
	*
	* Description:
	* vxfs_bmap_indir reads a &struct vxfs_typed at @indir
	* and performs the type-defined action.
	*
	* Return Value:
	* The physical block number on success, else Zero.
	*
	* Note:
	* Kernelstack is rare. Unrecurse?
	*/
	static daddr_t
	vxfs_bmap_indir(struct inode *ip, long indir, int size, long block)
	{
	struct buffer_head *bp = NULL;
	daddr_t pblock = 0;
	int i;

	for (i = 0; i < size * VXFS_TYPED_PER_BLOCK(ip->i_sb); i++) {
	struct vxfs_typed *typ;
	int64_t off;

	bp = sb_bread(ip->i_sb,
	indir + (i / VXFS_TYPED_PER_BLOCK(ip->i_sb)));
	if (!bp \|\| !buffer_mapped(bp))
	return 0;

	typ = ((struct vxfs_typed *)bp->b_data) +
	(i % VXFS_TYPED_PER_BLOCK(ip->i_sb));
	off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);

	if (block < off) {
	brelse(bp);
	continue;
	}

	switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
	case VXFS_TYPED_INDIRECT:
	pblock = vxfs_bmap_indir(ip, typ->vt_block,
	typ->vt_size, block - off);
	if (pblock == -2)
	break;
	goto out;
	case VXFS_TYPED_DATA:
	if ((block - off) >= typ->vt_size)
	break;
	pblock = (typ->vt_block + block - off);
	goto out;
	case VXFS_TYPED_INDIRECT_DEV4:
	case VXFS_TYPED_DATA_DEV4: {
	struct vxfs_typed_dev4 *typ4 =
	(struct vxfs_typed_dev4 *)typ;

	printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
	printk(KERN_INFO "block: %Lu\tsize: %Ld\tdev: %d\n",
	(unsigned long long) typ4->vd4_block,
	(unsigned long long) typ4->vd4_size,
	typ4->vd4_dev);
	goto fail;
	}
	default:
	BUG();
	}
	brelse(bp);
	}

	fail:
	pblock = 0;
	out:
	brelse(bp);
	return (pblock);
	}

	/**
	* vxfs_bmap_typed - bmap for typed extents
	* @ip: pointer to the inode we do bmap for
	* @iblock: logical block
	*
	* Description:
	* Performs the bmap operation for typed extents.
	*
	* Return Value:
	* The physical block number on success, else Zero.
	*/
	static daddr_t
	vxfs_bmap_typed(struct inode *ip, long iblock)
	{
	struct vxfs_inode_info *vip = VXFS_INO(ip);
	daddr_t pblock = 0;
	int i;

	for (i = 0; i < VXFS_NTYPED; i++) {
	struct vxfs_typed *typ = vip->vii_org.typed + i;
	int64_t off = (typ->vt_hdr & VXFS_TYPED_OFFSETMASK);

	#ifdef DIAGNOSTIC
	vxfs_typdump(typ);
	#endif
	if (iblock < off)
	continue;
	switch ((u_int32_t)(typ->vt_hdr >> VXFS_TYPED_TYPESHIFT)) {
	case VXFS_TYPED_INDIRECT:
	pblock = vxfs_bmap_indir(ip, typ->vt_block,
	typ->vt_size, iblock - off);
	if (pblock == -2)
	break;
	return (pblock);
	case VXFS_TYPED_DATA:
	if ((iblock - off) < typ->vt_size)
	return (typ->vt_block + iblock - off);
	break;
	case VXFS_TYPED_INDIRECT_DEV4:
	case VXFS_TYPED_DATA_DEV4: {
	struct vxfs_typed_dev4 *typ4 =
	(struct vxfs_typed_dev4 *)typ;

	printk(KERN_INFO "\n\nTYPED_DEV4 detected!\n");
	printk(KERN_INFO "block: %Lu\tsize: %Ld\tdev: %d\n",
	(unsigned long long) typ4->vd4_block,
	(unsigned long long) typ4->vd4_size,
	typ4->vd4_dev);
	return 0;
	}
	default:
	BUG();
	}
	}

	return 0;
	}

	/**
	* vxfs_bmap1 - vxfs-internal bmap operation
	* @ip: pointer to the inode we do bmap for
	* @iblock: logical block
	*
	* Description:
	* vxfs_bmap1 perfoms a logical to physical block mapping
	* for vxfs-internal purposes.
	*
	* Return Value:
	* The physical block number on success, else Zero.
	*/
	daddr_t
	vxfs_bmap1(struct inode *ip, long iblock)
	{
	struct vxfs_inode_info *vip = VXFS_INO(ip);

	if (VXFS_ISEXT4(vip))
	return vxfs_bmap_ext4(ip, iblock);
	if (VXFS_ISTYPED(vip))
	return vxfs_bmap_typed(ip, iblock);
	if (VXFS_ISNONE(vip))
	goto unsupp;
	if (VXFS_ISIMMED(vip))
	goto unsupp;

	printk(KERN_WARNING "vxfs: inode %ld has no valid orgtype (%x)\n",
	ip->i_ino, vip->vii_orgtype);
	BUG();

	unsupp:
	printk(KERN_WARNING "vxfs: inode %ld has an unsupported orgtype (%x)\n",
	ip->i_ino, vip->vii_orgtype);
	return 0;
	}