[deliverable/linux.git] / fs / udf / truncate.c

/*
 * truncate.c
 *
 * PURPOSE
 *	Truncate handling routines for the OSTA-UDF(tm) filesystem.
 *
 * COPYRIGHT
 *	This file is distributed under the terms of the GNU General Public
 *	License (GPL). Copies of the GPL can be obtained from:
 *		ftp://prep.ai.mit.edu/pub/gnu/GPL
 *	Each contributing author retains all rights to their own work.
 *
 *  (C) 1999-2004 Ben Fennema
 *  (C) 1999 Stelias Computing Inc
 *
 * HISTORY
 *
 *  02/24/99 blf  Created.
 *
 */

#include "udfdecl.h"
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/udf_fs.h>
#include <linux/buffer_head.h>

#include "udf_i.h"
#include "udf_sb.h"

static void extent_trunc(struct inode *inode, struct extent_position *epos,
			 kernel_lb_addr eloc, int8_t etype, uint32_t elen,
			 uint32_t nelen)
{
	kernel_lb_addr neloc = {};
	int last_block = (elen + inode->i_sb->s_blocksize - 1) >>
		inode->i_sb->s_blocksize_bits;
	int first_block = (nelen + inode->i_sb->s_blocksize - 1) >>
		inode->i_sb->s_blocksize_bits;

	if (nelen) {
		if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
			udf_free_blocks(inode->i_sb, inode, eloc, 0,
					last_block);
			etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
		} else
			neloc = eloc;
		nelen = (etype << 30) | nelen;
	}

	if (elen != nelen) {
		udf_write_aext(inode, epos, neloc, nelen, 0);
		if (last_block - first_block > 0) {
			if (etype == (EXT_RECORDED_ALLOCATED >> 30))
				mark_inode_dirty(inode);

			if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
				udf_free_blocks(inode->i_sb, inode, eloc,
						first_block,
						last_block - first_block);
		}
	}
}

/*
 * Truncate the last extent to match i_size. This function assumes
 * that preallocation extent is already truncated.
 */
void udf_truncate_tail_extent(struct inode *inode)
{
	struct extent_position epos = {};
	kernel_lb_addr eloc;
	uint32_t elen, nelen;
	uint64_t lbcount = 0;
	int8_t etype = -1, netype;
	int adsize;

	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB ||
	    inode->i_size == UDF_I_LENEXTENTS(inode))
		return;
	/* Are we going to delete the file anyway? */
	if (inode->i_nlink == 0)
		return;

	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(short_ad);
	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(long_ad);
	else
		BUG();

	/* Find the last extent in the file */
	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
		etype = netype;
		lbcount += elen;
		if (lbcount > inode->i_size) {
			if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)
				printk(KERN_WARNING
				       "udf_truncate_tail_extent(): Too long "
				       "extent after EOF in inode %u: i_size: "
				       "%Ld lbcount: %Ld extent %u+%u\n",
				       (unsigned)inode->i_ino,
				       (long long)inode->i_size,
				       (long long)lbcount,
				       (unsigned)eloc.logicalBlockNum,
				       (unsigned)elen);
			nelen = elen - (lbcount - inode->i_size);
			epos.offset -= adsize;
			extent_trunc(inode, &epos, eloc, etype, elen, nelen);
			epos.offset += adsize;
			if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1)
				printk(KERN_ERR "udf_truncate_tail_extent(): "
				       "Extent after EOF in inode %u.\n",
				       (unsigned)inode->i_ino);
			break;
		}
	}
	/* This inode entry is in-memory only and thus we don't have to mark
	 * the inode dirty */
	UDF_I_LENEXTENTS(inode) = inode->i_size;
	brelse(epos.bh);
}

void udf_discard_prealloc(struct inode *inode)
{
	struct extent_position epos = { NULL, 0, {0, 0} };
	kernel_lb_addr eloc;
	uint32_t elen;
	uint64_t lbcount = 0;
	int8_t etype = -1, netype;
	int adsize;

	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB ||
	    inode->i_size == UDF_I_LENEXTENTS(inode))
		return;

	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(short_ad);
	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(long_ad);
	else
		adsize = 0;

	epos.block = UDF_I_LOCATION(inode);

	/* Find the last extent in the file */
	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
		etype = netype;
		lbcount += elen;
	}
	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
		epos.offset -= adsize;
		lbcount -= elen;
		extent_trunc(inode, &epos, eloc, etype, elen, 0);
		if (!epos.bh) {
			UDF_I_LENALLOC(inode) =
				epos.offset - udf_file_entry_alloc_offset(inode);
			mark_inode_dirty(inode);
		} else {
			struct allocExtDesc *aed =
				(struct allocExtDesc *)(epos.bh->b_data);
			aed->lengthAllocDescs =
				cpu_to_le32(epos.offset -
					    sizeof(struct allocExtDesc));
			if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
			    UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
				udf_update_tag(epos.bh->b_data, epos.offset);
			else
				udf_update_tag(epos.bh->b_data,
					       sizeof(struct allocExtDesc));
			mark_buffer_dirty_inode(epos.bh, inode);
		}
	}
	/* This inode entry is in-memory only and thus we don't have to mark
	 * the inode dirty */
	UDF_I_LENEXTENTS(inode) = lbcount;
	brelse(epos.bh);
}

void udf_truncate_extents(struct inode *inode)
{
	struct extent_position epos;
	kernel_lb_addr eloc, neloc = {};
	uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
	int8_t etype;
	struct super_block *sb = inode->i_sb;
	struct udf_sb_info *sbi = UDF_SB(sb);
	sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;
	loff_t byte_offset;
	int adsize;

	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(short_ad);
	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(long_ad);
	else
		BUG();

	etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
	byte_offset = (offset << sb->s_blocksize_bits) +
		(inode->i_size & (sb->s_blocksize - 1));
	if (etype != -1) {
		epos.offset -= adsize;
		extent_trunc(inode, &epos, eloc, etype, elen, byte_offset);
		epos.offset += adsize;
		if (byte_offset)
			lenalloc = epos.offset;
		else
			lenalloc = epos.offset - adsize;

		if (!epos.bh)
			lenalloc -= udf_file_entry_alloc_offset(inode);
		else
			lenalloc -= sizeof(struct allocExtDesc);

		while ((etype = udf_current_aext(inode, &epos, &eloc, &elen, 0)) != -1) {
			if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30)) {
				udf_write_aext(inode, &epos, neloc, nelen, 0);
				if (indirect_ext_len) {
					/* We managed to free all extents in the
					 * indirect extent - free it too */
					if (!epos.bh)
						BUG();
					udf_free_blocks(sb, inode, epos.block,
							0, indirect_ext_len);
				} else {
					if (!epos.bh) {
						UDF_I_LENALLOC(inode) = lenalloc;
						mark_inode_dirty(inode);
					} else {
						struct allocExtDesc *aed =
							(struct allocExtDesc *)(epos.bh->b_data);
						aed->lengthAllocDescs =
						    cpu_to_le32(lenalloc);
						if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) ||
						    sbi->s_udfrev >= 0x0201)
							udf_update_tag(epos.bh->b_data,
								       lenalloc +
								       sizeof(struct allocExtDesc));
						else
							udf_update_tag(epos.bh->b_data,
								       sizeof(struct allocExtDesc));
						mark_buffer_dirty_inode(epos.bh, inode);
					}
				}
				brelse(epos.bh);
				epos.offset = sizeof(struct allocExtDesc);
				epos.block = eloc;
				epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, eloc, 0));
				if (elen)
					indirect_ext_len = (elen + sb->s_blocksize -1) >>
						sb->s_blocksize_bits;
				else
					indirect_ext_len = 1;
			} else {
				extent_trunc(inode, &epos, eloc, etype, elen, 0);
				epos.offset += adsize;
			}
		}

		if (indirect_ext_len) {
			if (!epos.bh)
				BUG();
			udf_free_blocks(sb, inode, epos.block, 0,
					indirect_ext_len);
		} else {
			if (!epos.bh) {
				UDF_I_LENALLOC(inode) = lenalloc;
				mark_inode_dirty(inode);
			} else {
				struct allocExtDesc *aed =
				    (struct allocExtDesc *)(epos.bh->b_data);
				aed->lengthAllocDescs = cpu_to_le32(lenalloc);
				if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) ||
				    sbi->s_udfrev >= 0x0201)
					udf_update_tag(epos.bh->b_data,
						       lenalloc + sizeof(struct allocExtDesc));
				else
					udf_update_tag(epos.bh->b_data,
						       sizeof(struct allocExtDesc));
				mark_buffer_dirty_inode(epos.bh, inode);
			}
		}
	} else if (inode->i_size) {
		if (byte_offset) {
			kernel_long_ad extent;

			/*
			 *  OK, there is not extent covering inode->i_size and
			 *  no extent above inode->i_size => truncate is
			 *  extending the file by 'offset' blocks.
			 */
			if ((!epos.bh &&
			     epos.offset == udf_file_entry_alloc_offset(inode)) ||
			    (epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
				/* File has no extents at all or has empty last
				 * indirect extent! Create a fake extent... */
				extent.extLocation.logicalBlockNum = 0;
				extent.extLocation.partitionReferenceNum = 0;
				extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
			} else {
				epos.offset -= adsize;
				etype = udf_next_aext(inode, &epos,
						      &extent.extLocation,
						      &extent.extLength, 0);
				extent.extLength |= etype << 30;
			}
			udf_extend_file(inode, &epos, &extent,
					offset + ((inode->i_size & (sb->s_blocksize - 1)) != 0));
		}
	}
	UDF_I_LENEXTENTS(inode) = inode->i_size;

	brelse(epos.bh);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* truncate.c
	3	*
	4	* PURPOSE
	5	* Truncate handling routines for the OSTA-UDF(tm) filesystem.
	6	*
1da177e4 LT	7	* COPYRIGHT
	8	* This file is distributed under the terms of the GNU General Public
	9	* License (GPL). Copies of the GPL can be obtained from:
	10	* ftp://prep.ai.mit.edu/pub/gnu/GPL
	11	* Each contributing author retains all rights to their own work.
	12	*
	13	* (C) 1999-2004 Ben Fennema
	14	* (C) 1999 Stelias Computing Inc
	15	*
	16	* HISTORY
	17	*
	18	* 02/24/99 blf Created.
	19	*
	20	*/
	21
	22	#include "udfdecl.h"
	23	#include <linux/fs.h>
	24	#include <linux/mm.h>
	25	#include <linux/udf_fs.h>
	26	#include <linux/buffer_head.h>
	27
	28	#include "udf_i.h"
	29	#include "udf_sb.h"
	30
cb00ea35 CG	31	static void extent_trunc(struct inode inode, struct extent_position epos,
	32	kernel_lb_addr eloc, int8_t etype, uint32_t elen,
	33	uint32_t nelen)
1da177e4	34	{
28de7948 CG	35	kernel_lb_addr neloc = {};
	36	int last_block = (elen + inode->i_sb->s_blocksize - 1) >>
	37	inode->i_sb->s_blocksize_bits;
	38	int first_block = (nelen + inode->i_sb->s_blocksize - 1) >>
	39	inode->i_sb->s_blocksize_bits;
1da177e4	40
cb00ea35 CG	41	if (nelen) {
	42	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
	43	udf_free_blocks(inode->i_sb, inode, eloc, 0,
	44	last_block);
1da177e4	45	etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
cb00ea35	46	} else
1da177e4 LT	47	neloc = eloc;
	48	nelen = (etype << 30) \| nelen;
	49	}
	50
cb00ea35	51	if (elen != nelen) {
ff116fc8	52	udf_write_aext(inode, epos, neloc, nelen, 0);
cb00ea35	53	if (last_block - first_block > 0) {
1da177e4 LT	54	if (etype == (EXT_RECORDED_ALLOCATED >> 30))
	55	mark_inode_dirty(inode);
	56
	57	if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
cb00ea35 CG	58	udf_free_blocks(inode->i_sb, inode, eloc,
	59	first_block,
	60	last_block - first_block);
1da177e4 LT	61	}
	62	}
	63	}
	64
74584ae5 JK	65	/*
	66	* Truncate the last extent to match i_size. This function assumes
	67	* that preallocation extent is already truncated.
	68	*/
	69	void udf_truncate_tail_extent(struct inode *inode)
1da177e4	70	{
28de7948	71	struct extent_position epos = {};
ff116fc8 JK	72	kernel_lb_addr eloc;
ff116fc8 JK	73	uint32_t elen, nelen;
1da177e4 LT	74	uint64_t lbcount = 0;
1da177e4 LT	75	int8_t etype = -1, netype;
1da177e4 LT	76	int adsize;
	77
	78	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB \|\|
74584ae5 JK	79	inode->i_size == UDF_I_LENEXTENTS(inode))
	80	return;
	81	/* Are we going to delete the file anyway? */
	82	if (inode->i_nlink == 0)
1da177e4	83	return;
1da177e4 LT	84
	85	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
	86	adsize = sizeof(short_ad);
	87	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
	88	adsize = sizeof(long_ad);
	89	else
74584ae5	90	BUG();
1da177e4	91
ff116fc8	92	/* Find the last extent in the file */
cb00ea35	93	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
1da177e4 LT	94	etype = netype;
1da177e4 LT	95	lbcount += elen;
74584ae5 JK	96	if (lbcount > inode->i_size) {
	97	if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)
	98	printk(KERN_WARNING
	99	"udf_truncate_tail_extent(): Too long "
	100	"extent after EOF in inode %u: i_size: "
	101	"%Ld lbcount: %Ld extent %u+%u\n",
	102	(unsigned)inode->i_ino,
	103	(long long)inode->i_size,
	104	(long long)lbcount,
	105	(unsigned)eloc.logicalBlockNum,
	106	(unsigned)elen);
1da177e4	107	nelen = elen - (lbcount - inode->i_size);
ff116fc8 JK	108	epos.offset -= adsize;
	109	extent_trunc(inode, &epos, eloc, etype, elen, nelen);
	110	epos.offset += adsize;
74584ae5 JK	111	if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1)
	112	printk(KERN_ERR "udf_truncate_tail_extent(): "
	113	"Extent after EOF in inode %u.\n",
	114	(unsigned)inode->i_ino);
	115	break;
1da177e4 LT	116	}
1da177e4 LT	117	}
74584ae5 JK	118	/* This inode entry is in-memory only and thus we don't have to mark
	119	* the inode dirty */
	120	UDF_I_LENEXTENTS(inode) = inode->i_size;
	121	brelse(epos.bh);
	122	}
	123
	124	void udf_discard_prealloc(struct inode *inode)
	125	{
cb00ea35	126	struct extent_position epos = { NULL, 0, {0, 0} };
74584ae5 JK	127	kernel_lb_addr eloc;
	128	uint32_t elen;
	129	uint64_t lbcount = 0;
	130	int8_t etype = -1, netype;
	131	int adsize;
	132
	133	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB \|\|
cb00ea35	134	inode->i_size == UDF_I_LENEXTENTS(inode))
74584ae5 JK	135	return;
	136
	137	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
	138	adsize = sizeof(short_ad);
	139	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
	140	adsize = sizeof(long_ad);
	141	else
	142	adsize = 0;
	143
	144	epos.block = UDF_I_LOCATION(inode);
	145
	146	/* Find the last extent in the file */
	147	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
	148	etype = netype;
	149	lbcount += elen;
	150	}
ff116fc8 JK	151	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
ff116fc8 JK	152	epos.offset -= adsize;
1da177e4	153	lbcount -= elen;
ff116fc8	154	extent_trunc(inode, &epos, eloc, etype, elen, 0);
74584ae5	155	if (!epos.bh) {
cb00ea35	156	UDF_I_LENALLOC(inode) =
28de7948	157	epos.offset - udf_file_entry_alloc_offset(inode);
1da177e4	158	mark_inode_dirty(inode);
74584ae5	159	} else {
cb00ea35	160	struct allocExtDesc *aed =
28de7948	161	(struct allocExtDesc *)(epos.bh->b_data);
cb00ea35	162	aed->lengthAllocDescs =
28de7948 CG	163	cpu_to_le32(epos.offset -
	164	sizeof(struct allocExtDesc));
	165	if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) \|\|
6c79e987	166	UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
ff116fc8	167	udf_update_tag(epos.bh->b_data, epos.offset);
1da177e4	168	else
cb00ea35 CG	169	udf_update_tag(epos.bh->b_data,
cb00ea35 CG	170	sizeof(struct allocExtDesc));
ff116fc8	171	mark_buffer_dirty_inode(epos.bh, inode);
1da177e4 LT	172	}
1da177e4 LT	173	}
74584ae5 JK	174	/* This inode entry is in-memory only and thus we don't have to mark
74584ae5 JK	175	* the inode dirty */
1da177e4	176	UDF_I_LENEXTENTS(inode) = lbcount;
3bf25cb4	177	brelse(epos.bh);
1da177e4 LT	178	}
1da177e4 LT	179
cb00ea35	180	void udf_truncate_extents(struct inode *inode)
1da177e4	181	{
ff116fc8	182	struct extent_position epos;
28de7948	183	kernel_lb_addr eloc, neloc = {};
ff116fc8	184	uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
1da177e4	185	int8_t etype;
31170b6a	186	struct super_block *sb = inode->i_sb;
6c79e987	187	struct udf_sb_info *sbi = UDF_SB(sb);
31170b6a	188	sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;
60448b1d	189	loff_t byte_offset;
1da177e4 LT	190	int adsize;
	191
	192	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
	193	adsize = sizeof(short_ad);
	194	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
	195	adsize = sizeof(long_ad);
	196	else
ff116fc8	197	BUG();
1da177e4	198
ff116fc8	199	etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
28de7948 CG	200	byte_offset = (offset << sb->s_blocksize_bits) +
28de7948 CG	201	(inode->i_size & (sb->s_blocksize - 1));
cb00ea35	202	if (etype != -1) {
ff116fc8 JK	203	epos.offset -= adsize;
	204	extent_trunc(inode, &epos, eloc, etype, elen, byte_offset);
	205	epos.offset += adsize;
60448b1d	206	if (byte_offset)
ff116fc8	207	lenalloc = epos.offset;
1da177e4	208	else
ff116fc8	209	lenalloc = epos.offset - adsize;
1da177e4	210
ff116fc8	211	if (!epos.bh)
1da177e4 LT	212	lenalloc -= udf_file_entry_alloc_offset(inode);
	213	else
	214	lenalloc -= sizeof(struct allocExtDesc);
	215
28de7948	216	while ((etype = udf_current_aext(inode, &epos, &eloc, &elen, 0)) != -1) {
cb00ea35	217	if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30)) {
ff116fc8	218	udf_write_aext(inode, &epos, neloc, nelen, 0);
cb00ea35	219	if (indirect_ext_len) {
ff116fc8 JK	220	/* We managed to free all extents in the
	221	* indirect extent - free it too */
	222	if (!epos.bh)
1da177e4	223	BUG();
cb00ea35 CG	224	udf_free_blocks(sb, inode, epos.block,
	225	0, indirect_ext_len);
	226	} else {
	227	if (!epos.bh) {
28de7948	228	UDF_I_LENALLOC(inode) = lenalloc;
1da177e4	229	mark_inode_dirty(inode);
cb00ea35 CG	230	} else {
cb00ea35 CG	231	struct allocExtDesc *aed =
28de7948	232	(struct allocExtDesc *)(epos.bh->b_data);
cb00ea35 CG	233	aed->lengthAllocDescs =
cb00ea35 CG	234	cpu_to_le32(lenalloc);
28de7948	235	if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) \|\|
6c79e987	236	sbi->s_udfrev >= 0x0201)
28de7948 CG	237	udf_update_tag(epos.bh->b_data,
	238	lenalloc +
	239	sizeof(struct allocExtDesc));
1da177e4	240	else
28de7948 CG	241	udf_update_tag(epos.bh->b_data,
	242	sizeof(struct allocExtDesc));
	243	mark_buffer_dirty_inode(epos.bh, inode);
1da177e4 LT	244	}
1da177e4 LT	245	}
ff116fc8 JK	246	brelse(epos.bh);
	247	epos.offset = sizeof(struct allocExtDesc);
	248	epos.block = eloc;
28de7948	249	epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, eloc, 0));
1da177e4	250	if (elen)
28de7948 CG	251	indirect_ext_len = (elen + sb->s_blocksize -1) >>
28de7948 CG	252	sb->s_blocksize_bits;
1da177e4	253	else
ff116fc8	254	indirect_ext_len = 1;
cb00ea35	255	} else {
28de7948	256	extent_trunc(inode, &epos, eloc, etype, elen, 0);
ff116fc8	257	epos.offset += adsize;
1da177e4 LT	258	}
	259	}
	260
cb00ea35	261	if (indirect_ext_len) {
ff116fc8	262	if (!epos.bh)
1da177e4	263	BUG();
cb00ea35 CG	264	udf_free_blocks(sb, inode, epos.block, 0,
	265	indirect_ext_len);
	266	} else {
	267	if (!epos.bh) {
1da177e4 LT	268	UDF_I_LENALLOC(inode) = lenalloc;
1da177e4 LT	269	mark_inode_dirty(inode);
cb00ea35 CG	270	} else {
	271	struct allocExtDesc *aed =
	272	(struct allocExtDesc *)(epos.bh->b_data);
1da177e4	273	aed->lengthAllocDescs = cpu_to_le32(lenalloc);
28de7948	274	if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) \|\|
6c79e987	275	sbi->s_udfrev >= 0x0201)
cb00ea35	276	udf_update_tag(epos.bh->b_data,
28de7948	277	lenalloc + sizeof(struct allocExtDesc));
1da177e4	278	else
cb00ea35	279	udf_update_tag(epos.bh->b_data,
28de7948	280	sizeof(struct allocExtDesc));
ff116fc8	281	mark_buffer_dirty_inode(epos.bh, inode);
1da177e4 LT	282	}
1da177e4 LT	283	}
cb00ea35 CG	284	} else if (inode->i_size) {
cb00ea35 CG	285	if (byte_offset) {
31170b6a JK	286	kernel_long_ad extent;
31170b6a JK	287
00a2b0f6 JK	288	/*
	289	* OK, there is not extent covering inode->i_size and
	290	* no extent above inode->i_size => truncate is
31170b6a	291	* extending the file by 'offset' blocks.
00a2b0f6	292	*/
28de7948 CG	293	if ((!epos.bh &&
	294	epos.offset == udf_file_entry_alloc_offset(inode)) \|\|
	295	(epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
31170b6a JK	296	/* File has no extents at all or has empty last
	297	* indirect extent! Create a fake extent... */
	298	extent.extLocation.logicalBlockNum = 0;
	299	extent.extLocation.partitionReferenceNum = 0;
28de7948	300	extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
cb00ea35	301	} else {
ff116fc8	302	epos.offset -= adsize;
31170b6a	303	etype = udf_next_aext(inode, &epos,
cb00ea35 CG	304	&extent.extLocation,
cb00ea35 CG	305	&extent.extLength, 0);
31170b6a	306	extent.extLength \|= etype << 30;
1da177e4	307	}
cb00ea35	308	udf_extend_file(inode, &epos, &extent,
28de7948	309	offset + ((inode->i_size & (sb->s_blocksize - 1)) != 0));
1da177e4 LT	310	}
	311	}
	312	UDF_I_LENEXTENTS(inode) = inode->i_size;
	313
3bf25cb4	314	brelse(epos.bh);
1da177e4	315	}