fs/ufs/truncate.c - kernel/msm - Gitiles

 /*
  *  linux/fs/ufs/truncate.c
  *
  * Copyright (C) 1998
  * Daniel Pirkl <daniel.pirkl@email.cz>
  * Charles University, Faculty of Mathematics and Physics
  *
  *  from
  *
  *  linux/fs/ext2/truncate.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/truncate.c
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  *  Big-endian to little-endian byte-swapping/bitmaps by
  *        David S. Miller (davem@caip.rutgers.edu), 1995
  */

 /*
  * Real random numbers for secure rm added 94/02/18
  * Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
  */

 /*
  * Modified to avoid infinite loop on 2006 by
  * Evgeniy Dushistov <dushistov@mail.ru>
  */

 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/ufs_fs.h>
 #include <linux/fcntl.h>
 #include <linux/time.h>
 #include <linux/stat.h>
 #include <linux/string.h>
 #include <linux/smp_lock.h>
 #include <linux/buffer_head.h>
 #include <linux/blkdev.h>
 #include <linux/sched.h>

 #include "swab.h"
 #include "util.h"

 /*
  * Secure deletion currently doesn't work. It interacts very badly
  * with buffers shared with memory mappings, and for that reason
  * can't be done in the truncate() routines. It should instead be
  * done separately in "release()" before calling the truncate routines
  * that will release the actual file blocks.
  *
  *		Linus
  */

 #define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
 #define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)


 static int ufs_trunc_direct (struct inode * inode)
 {
 	struct ufs_inode_info *ufsi = UFS_I(inode);
 	struct super_block * sb;
 	struct ufs_sb_private_info * uspi;
 	__fs32 * p;
 	unsigned frag1, frag2, frag3, frag4, block1, block2;
 	unsigned frag_to_free, free_count;
 	unsigned i, tmp;
 	int retry;

 	UFSD("ENTER\n");

 	sb = inode->i_sb;
 	uspi = UFS_SB(sb)->s_uspi;

 	frag_to_free = 0;
 	free_count = 0;
 	retry = 0;

 	frag1 = DIRECT_FRAGMENT;
 	frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
 	frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
 	frag3 = frag4 & ~uspi->s_fpbmask;
 	block1 = block2 = 0;
 	if (frag2 > frag3) {
 		frag2 = frag4;
 		frag3 = frag4 = 0;
 	}
 	else if (frag2 < frag3) {
 		block1 = ufs_fragstoblks (frag2);
 		block2 = ufs_fragstoblks (frag3);
 	}

 	UFSD("frag1 %u, frag2 %u, block1 %u, block2 %u, frag3 %u, frag4 %u\n", frag1, frag2, block1, block2, frag3, frag4);

 	if (frag1 >= frag2)
 		goto next1;

 	/*
 	 * Free first free fragments
 	 */
 	p = ufsi->i_u1.i_data + ufs_fragstoblks (frag1);
 	tmp = fs32_to_cpu(sb, *p);
 	if (!tmp )
 		ufs_panic (sb, "ufs_trunc_direct", "internal error");
 	frag1 = ufs_fragnum (frag1);
 	frag2 = ufs_fragnum (frag2);

 	ufs_free_fragments (inode, tmp + frag1, frag2 - frag1);
 	mark_inode_dirty(inode);
 	frag_to_free = tmp + frag1;

 next1:
 	/*
 	 * Free whole blocks
 	 */
 	for (i = block1 ; i < block2; i++) {
 		p = ufsi->i_u1.i_data + i;
 		tmp = fs32_to_cpu(sb, *p);
 		if (!tmp)
 			continue;

 		*p = 0;

 		if (free_count == 0) {
 			frag_to_free = tmp;
 			free_count = uspi->s_fpb;
 		} else if (free_count > 0 && frag_to_free == tmp - free_count)
 			free_count += uspi->s_fpb;
 		else {
 			ufs_free_blocks (inode, frag_to_free, free_count);
 			frag_to_free = tmp;
 			free_count = uspi->s_fpb;
 		}
 		mark_inode_dirty(inode);
 	}

 	if (free_count > 0)
 		ufs_free_blocks (inode, frag_to_free, free_count);

 	if (frag3 >= frag4)
 		goto next3;

 	/*
 	 * Free last free fragments
 	 */
 	p = ufsi->i_u1.i_data + ufs_fragstoblks (frag3);
 	tmp = fs32_to_cpu(sb, *p);
 	if (!tmp )
 		ufs_panic(sb, "ufs_truncate_direct", "internal error");
 	frag4 = ufs_fragnum (frag4);

 	*p = 0;

 	ufs_free_fragments (inode, tmp, frag4);
 	mark_inode_dirty(inode);
  next3:

 	UFSD("EXIT\n");
 	return retry;
 }


 static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
 {
 	struct super_block * sb;
 	struct ufs_sb_private_info * uspi;
 	struct ufs_buffer_head * ind_ubh;
 	__fs32 * ind;
 	unsigned indirect_block, i, tmp;
 	unsigned frag_to_free, free_count;
 	int retry;

 	UFSD("ENTER\n");

 	sb = inode->i_sb;
 	uspi = UFS_SB(sb)->s_uspi;

 	frag_to_free = 0;
 	free_count = 0;
 	retry = 0;

 	tmp = fs32_to_cpu(sb, *p);
 	if (!tmp)
 		return 0;
 	ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
 	if (tmp != fs32_to_cpu(sb, *p)) {
 		ubh_brelse (ind_ubh);
 		return 1;
 	}
 	if (!ind_ubh) {
 		*p = 0;
 		return 0;
 	}

 	indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
 	for (i = indirect_block; i < uspi->s_apb; i++) {
 		ind = ubh_get_addr32 (ind_ubh, i);
 		tmp = fs32_to_cpu(sb, *ind);
 		if (!tmp)
 			continue;

 		*ind = 0;
 		ubh_mark_buffer_dirty(ind_ubh);
 		if (free_count == 0) {
 			frag_to_free = tmp;
 			free_count = uspi->s_fpb;
 		} else if (free_count > 0 && frag_to_free == tmp - free_count)
 			free_count += uspi->s_fpb;
 		else {
 			ufs_free_blocks (inode, frag_to_free, free_count);
 			frag_to_free = tmp;
 			free_count = uspi->s_fpb;
 		}

 		mark_inode_dirty(inode);
 	}

 	if (free_count > 0) {
 		ufs_free_blocks (inode, frag_to_free, free_count);
 	}
 	for (i = 0; i < uspi->s_apb; i++)
 		if (*ubh_get_addr32(ind_ubh,i))
 			break;
 	if (i >= uspi->s_apb) {
 		tmp = fs32_to_cpu(sb, *p);
 		*p = 0;

 		ufs_free_blocks (inode, tmp, uspi->s_fpb);
 		mark_inode_dirty(inode);
 		ubh_bforget(ind_ubh);
 		ind_ubh = NULL;
 	}
 	if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
 		ubh_ll_rw_block(SWRITE, ind_ubh);
 		ubh_wait_on_buffer (ind_ubh);
 	}
 	ubh_brelse (ind_ubh);

 	UFSD("EXIT\n");

 	return retry;
 }

 static int ufs_trunc_dindirect (struct inode *inode, unsigned offset, __fs32 *p)
 {
 	struct super_block * sb;
 	struct ufs_sb_private_info * uspi;
 	struct ufs_buffer_head * dind_bh;
 	unsigned i, tmp, dindirect_block;
 	__fs32 * dind;
 	int retry = 0;

 	UFSD("ENTER\n");

 	sb = inode->i_sb;
 	uspi = UFS_SB(sb)->s_uspi;

 	dindirect_block = (DIRECT_BLOCK > offset)
 		? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
 	retry = 0;

 	tmp = fs32_to_cpu(sb, *p);
 	if (!tmp)
 		return 0;
 	dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
 	if (tmp != fs32_to_cpu(sb, *p)) {
 		ubh_brelse (dind_bh);
 		return 1;
 	}
 	if (!dind_bh) {
 		*p = 0;
 		return 0;
 	}

 	for (i = dindirect_block ; i < uspi->s_apb ; i++) {
 		dind = ubh_get_addr32 (dind_bh, i);
 		tmp = fs32_to_cpu(sb, *dind);
 		if (!tmp)
 			continue;
 		retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
 		ubh_mark_buffer_dirty(dind_bh);
 	}

 	for (i = 0; i < uspi->s_apb; i++)
 		if (*ubh_get_addr32 (dind_bh, i))
 			break;
 	if (i >= uspi->s_apb) {
 		tmp = fs32_to_cpu(sb, *p);
 		*p = 0;

 		ufs_free_blocks(inode, tmp, uspi->s_fpb);
 		mark_inode_dirty(inode);
 		ubh_bforget(dind_bh);
 		dind_bh = NULL;
 	}
 	if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
 		ubh_ll_rw_block(SWRITE, dind_bh);
 		ubh_wait_on_buffer (dind_bh);
 	}
 	ubh_brelse (dind_bh);

 	UFSD("EXIT\n");

 	return retry;
 }

 static int ufs_trunc_tindirect (struct inode * inode)
 {
 	struct ufs_inode_info *ufsi = UFS_I(inode);
 	struct super_block * sb;
 	struct ufs_sb_private_info * uspi;
 	struct ufs_buffer_head * tind_bh;
 	unsigned tindirect_block, tmp, i;
 	__fs32 * tind, * p;
 	int retry;

 	UFSD("ENTER\n");

 	sb = inode->i_sb;
 	uspi = UFS_SB(sb)->s_uspi;
 	retry = 0;

 	tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
 		? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
 	p = ufsi->i_u1.i_data + UFS_TIND_BLOCK;
 	if (!(tmp = fs32_to_cpu(sb, *p)))
 		return 0;
 	tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
 	if (tmp != fs32_to_cpu(sb, *p)) {
 		ubh_brelse (tind_bh);
 		return 1;
 	}
 	if (!tind_bh) {
 		*p = 0;
 		return 0;
 	}

 	for (i = tindirect_block ; i < uspi->s_apb ; i++) {
 		tind = ubh_get_addr32 (tind_bh, i);
 		retry |= ufs_trunc_dindirect(inode, UFS_NDADDR +
 			uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
 		ubh_mark_buffer_dirty(tind_bh);
 	}
 	for (i = 0; i < uspi->s_apb; i++)
 		if (*ubh_get_addr32 (tind_bh, i))
 			break;
 	if (i >= uspi->s_apb) {
 		tmp = fs32_to_cpu(sb, *p);
 		*p = 0;

 		ufs_free_blocks(inode, tmp, uspi->s_fpb);
 		mark_inode_dirty(inode);
 		ubh_bforget(tind_bh);
 		tind_bh = NULL;
 	}
 	if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
 		ubh_ll_rw_block(SWRITE, tind_bh);
 		ubh_wait_on_buffer (tind_bh);
 	}
 	ubh_brelse (tind_bh);

 	UFSD("EXIT\n");
 	return retry;
 }

 void ufs_truncate (struct inode * inode)
 {
 	struct ufs_inode_info *ufsi = UFS_I(inode);
 	struct super_block * sb;
 	struct ufs_sb_private_info * uspi;
 	int retry;

 	UFSD("ENTER\n");
 	sb = inode->i_sb;
 	uspi = UFS_SB(sb)->s_uspi;

 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
 		return;
 	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 		return;

 	block_truncate_page(inode->i_mapping,	inode->i_size, ufs_getfrag_block);

 	lock_kernel();
 	while (1) {
 		retry = ufs_trunc_direct(inode);
 		retry |= ufs_trunc_indirect (inode, UFS_IND_BLOCK,
 			(__fs32 *) &ufsi->i_u1.i_data[UFS_IND_BLOCK]);
 		retry |= ufs_trunc_dindirect (inode, UFS_IND_BLOCK + uspi->s_apb,
 			(__fs32 *) &ufsi->i_u1.i_data[UFS_DIND_BLOCK]);
 		retry |= ufs_trunc_tindirect (inode);
 		if (!retry)
 			break;
 		if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
 			ufs_sync_inode (inode);
 		blk_run_address_space(inode->i_mapping);
 		yield();
 	}

 	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 	ufsi->i_lastfrag = DIRECT_FRAGMENT;
 	unlock_kernel();
 	mark_inode_dirty(inode);
 	UFSD("EXIT\n");
 }
	/*
	* linux/fs/ufs/truncate.c
	*
	* Copyright (C) 1998
	* Daniel Pirkl <daniel.pirkl@email.cz>
	* Charles University, Faculty of Mathematics and Physics
	*
	* from
	*
	* linux/fs/ext2/truncate.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/truncate.c
	*
	* Copyright (C) 1991, 1992 Linus Torvalds
	*
	* Big-endian to little-endian byte-swapping/bitmaps by
	* David S. Miller (davem@caip.rutgers.edu), 1995
	*/

	/*
	* Real random numbers for secure rm added 94/02/18
	* Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
	*/

	/*
	* Modified to avoid infinite loop on 2006 by
	* Evgeniy Dushistov <dushistov@mail.ru>
	*/

	#include <linux/errno.h>
	#include <linux/fs.h>
	#include <linux/ufs_fs.h>
	#include <linux/fcntl.h>
	#include <linux/time.h>
	#include <linux/stat.h>
	#include <linux/string.h>
	#include <linux/smp_lock.h>
	#include <linux/buffer_head.h>
	#include <linux/blkdev.h>
	#include <linux/sched.h>

	#include "swab.h"
	#include "util.h"

	/*
	* Secure deletion currently doesn't work. It interacts very badly
	* with buffers shared with memory mappings, and for that reason
	* can't be done in the truncate() routines. It should instead be
	* done separately in "release()" before calling the truncate routines
	* that will release the actual file blocks.
	*
	* Linus
	*/

	#define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
	#define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)


	static int ufs_trunc_direct (struct inode * inode)
	{
	struct ufs_inode_info *ufsi = UFS_I(inode);
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	__fs32 * p;
	unsigned frag1, frag2, frag3, frag4, block1, block2;
	unsigned frag_to_free, free_count;
	unsigned i, tmp;
	int retry;

	UFSD("ENTER\n");

	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;

	frag_to_free = 0;
	free_count = 0;
	retry = 0;

	frag1 = DIRECT_FRAGMENT;
	frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
	frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 \| uspi->s_fpbmask) + 1) : frag1);
	frag3 = frag4 & ~uspi->s_fpbmask;
	block1 = block2 = 0;
	if (frag2 > frag3) {
	frag2 = frag4;
	frag3 = frag4 = 0;
	}
	else if (frag2 < frag3) {
	block1 = ufs_fragstoblks (frag2);
	block2 = ufs_fragstoblks (frag3);
	}

	UFSD("frag1 %u, frag2 %u, block1 %u, block2 %u, frag3 %u, frag4 %u\n", frag1, frag2, block1, block2, frag3, frag4);

	if (frag1 >= frag2)
	goto next1;

	/*
	* Free first free fragments
	*/
	p = ufsi->i_u1.i_data + ufs_fragstoblks (frag1);
	tmp = fs32_to_cpu(sb, *p);
	if (!tmp )
	ufs_panic (sb, "ufs_trunc_direct", "internal error");
	frag1 = ufs_fragnum (frag1);
	frag2 = ufs_fragnum (frag2);

	ufs_free_fragments (inode, tmp + frag1, frag2 - frag1);
	mark_inode_dirty(inode);
	frag_to_free = tmp + frag1;

	next1:
	/*
	* Free whole blocks
	*/
	for (i = block1 ; i < block2; i++) {
	p = ufsi->i_u1.i_data + i;
	tmp = fs32_to_cpu(sb, *p);
	if (!tmp)
	continue;

	*p = 0;

	if (free_count == 0) {
	frag_to_free = tmp;
	free_count = uspi->s_fpb;
	} else if (free_count > 0 && frag_to_free == tmp - free_count)
	free_count += uspi->s_fpb;
	else {
	ufs_free_blocks (inode, frag_to_free, free_count);
	frag_to_free = tmp;
	free_count = uspi->s_fpb;
	}
	mark_inode_dirty(inode);
	}

	if (free_count > 0)
	ufs_free_blocks (inode, frag_to_free, free_count);

	if (frag3 >= frag4)
	goto next3;

	/*
	* Free last free fragments
	*/
	p = ufsi->i_u1.i_data + ufs_fragstoblks (frag3);
	tmp = fs32_to_cpu(sb, *p);
	if (!tmp )
	ufs_panic(sb, "ufs_truncate_direct", "internal error");
	frag4 = ufs_fragnum (frag4);

	*p = 0;

	ufs_free_fragments (inode, tmp, frag4);
	mark_inode_dirty(inode);
	next3:

	UFSD("EXIT\n");
	return retry;
	}


	static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
	{
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct ufs_buffer_head * ind_ubh;
	__fs32 * ind;
	unsigned indirect_block, i, tmp;
	unsigned frag_to_free, free_count;
	int retry;

	UFSD("ENTER\n");

	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;

	frag_to_free = 0;
	free_count = 0;
	retry = 0;

	tmp = fs32_to_cpu(sb, *p);
	if (!tmp)
	return 0;
	ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
	if (tmp != fs32_to_cpu(sb, *p)) {
	ubh_brelse (ind_ubh);
	return 1;
	}
	if (!ind_ubh) {
	*p = 0;
	return 0;
	}

	indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
	for (i = indirect_block; i < uspi->s_apb; i++) {
	ind = ubh_get_addr32 (ind_ubh, i);
	tmp = fs32_to_cpu(sb, *ind);
	if (!tmp)
	continue;

	*ind = 0;
	ubh_mark_buffer_dirty(ind_ubh);
	if (free_count == 0) {
	frag_to_free = tmp;
	free_count = uspi->s_fpb;
	} else if (free_count > 0 && frag_to_free == tmp - free_count)
	free_count += uspi->s_fpb;
	else {
	ufs_free_blocks (inode, frag_to_free, free_count);
	frag_to_free = tmp;
	free_count = uspi->s_fpb;
	}

	mark_inode_dirty(inode);
	}

	if (free_count > 0) {
	ufs_free_blocks (inode, frag_to_free, free_count);
	}
	for (i = 0; i < uspi->s_apb; i++)
	if (*ubh_get_addr32(ind_ubh,i))
	break;
	if (i >= uspi->s_apb) {
	tmp = fs32_to_cpu(sb, *p);
	*p = 0;

	ufs_free_blocks (inode, tmp, uspi->s_fpb);
	mark_inode_dirty(inode);
	ubh_bforget(ind_ubh);
	ind_ubh = NULL;
	}
	if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
	ubh_ll_rw_block(SWRITE, ind_ubh);
	ubh_wait_on_buffer (ind_ubh);
	}
	ubh_brelse (ind_ubh);

	UFSD("EXIT\n");

	return retry;
	}

	static int ufs_trunc_dindirect (struct inode inode, unsigned offset, __fs32 p)
	{
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct ufs_buffer_head * dind_bh;
	unsigned i, tmp, dindirect_block;
	__fs32 * dind;
	int retry = 0;

	UFSD("ENTER\n");

	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;

	dindirect_block = (DIRECT_BLOCK > offset)
	? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
	retry = 0;

	tmp = fs32_to_cpu(sb, *p);
	if (!tmp)
	return 0;
	dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
	if (tmp != fs32_to_cpu(sb, *p)) {
	ubh_brelse (dind_bh);
	return 1;
	}
	if (!dind_bh) {
	*p = 0;
	return 0;
	}

	for (i = dindirect_block ; i < uspi->s_apb ; i++) {
	dind = ubh_get_addr32 (dind_bh, i);
	tmp = fs32_to_cpu(sb, *dind);
	if (!tmp)
	continue;
	retry \|= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
	ubh_mark_buffer_dirty(dind_bh);
	}

	for (i = 0; i < uspi->s_apb; i++)
	if (*ubh_get_addr32 (dind_bh, i))
	break;
	if (i >= uspi->s_apb) {
	tmp = fs32_to_cpu(sb, *p);
	*p = 0;

	ufs_free_blocks(inode, tmp, uspi->s_fpb);
	mark_inode_dirty(inode);
	ubh_bforget(dind_bh);
	dind_bh = NULL;
	}
	if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
	ubh_ll_rw_block(SWRITE, dind_bh);
	ubh_wait_on_buffer (dind_bh);
	}
	ubh_brelse (dind_bh);

	UFSD("EXIT\n");

	return retry;
	}

	static int ufs_trunc_tindirect (struct inode * inode)
	{
	struct ufs_inode_info *ufsi = UFS_I(inode);
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	struct ufs_buffer_head * tind_bh;
	unsigned tindirect_block, tmp, i;
	__fs32 * tind, * p;
	int retry;

	UFSD("ENTER\n");

	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;
	retry = 0;

	tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
	? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
	p = ufsi->i_u1.i_data + UFS_TIND_BLOCK;
	if (!(tmp = fs32_to_cpu(sb, *p)))
	return 0;
	tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
	if (tmp != fs32_to_cpu(sb, *p)) {
	ubh_brelse (tind_bh);
	return 1;
	}
	if (!tind_bh) {
	*p = 0;
	return 0;
	}

	for (i = tindirect_block ; i < uspi->s_apb ; i++) {
	tind = ubh_get_addr32 (tind_bh, i);
	retry \|= ufs_trunc_dindirect(inode, UFS_NDADDR +
	uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
	ubh_mark_buffer_dirty(tind_bh);
	}
	for (i = 0; i < uspi->s_apb; i++)
	if (*ubh_get_addr32 (tind_bh, i))
	break;
	if (i >= uspi->s_apb) {
	tmp = fs32_to_cpu(sb, *p);
	*p = 0;

	ufs_free_blocks(inode, tmp, uspi->s_fpb);
	mark_inode_dirty(inode);
	ubh_bforget(tind_bh);
	tind_bh = NULL;
	}
	if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
	ubh_ll_rw_block(SWRITE, tind_bh);
	ubh_wait_on_buffer (tind_bh);
	}
	ubh_brelse (tind_bh);

	UFSD("EXIT\n");
	return retry;
	}

	void ufs_truncate (struct inode * inode)
	{
	struct ufs_inode_info *ufsi = UFS_I(inode);
	struct super_block * sb;
	struct ufs_sb_private_info * uspi;
	int retry;

	UFSD("ENTER\n");
	sb = inode->i_sb;
	uspi = UFS_SB(sb)->s_uspi;

	if (!(S_ISREG(inode->i_mode) \|\| S_ISDIR(inode->i_mode) \|\| S_ISLNK(inode->i_mode)))
	return;
	if (IS_APPEND(inode) \|\| IS_IMMUTABLE(inode))
	return;

	block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);

	lock_kernel();
	while (1) {
	retry = ufs_trunc_direct(inode);
	retry \|= ufs_trunc_indirect (inode, UFS_IND_BLOCK,
	(__fs32 *) &ufsi->i_u1.i_data[UFS_IND_BLOCK]);
	retry \|= ufs_trunc_dindirect (inode, UFS_IND_BLOCK + uspi->s_apb,
	(__fs32 *) &ufsi->i_u1.i_data[UFS_DIND_BLOCK]);
	retry \|= ufs_trunc_tindirect (inode);
	if (!retry)
	break;
	if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
	ufs_sync_inode (inode);
	blk_run_address_space(inode->i_mapping);
	yield();
	}

	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
	ufsi->i_lastfrag = DIRECT_FRAGMENT;
	unlock_kernel();
	mark_inode_dirty(inode);
	UFSD("EXIT\n");
	}