[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;
	struct udf_inode_info *iinfo = UDF_I(inode);

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

	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(short_ad);
	else if (iinfo->i_alloc_type == 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 */
	iinfo->i_lenExtents = 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;
	struct udf_inode_info *iinfo = UDF_I(inode);

	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
	    inode->i_size == iinfo->i_lenExtents)
		return;

	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(short_ad);
	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(long_ad);
	else
		adsize = 0;

	epos.block = iinfo->i_location;

	/* 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) {
			iinfo->i_lenAlloc =
				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 */
	iinfo->i_lenExtents = 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;
	struct udf_inode_info *iinfo = UDF_I(inode);

	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(short_ad);
	else if (iinfo->i_alloc_type == 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) {
						iinfo->i_lenAlloc =
								lenalloc;
						mark_inode_dirty(inode);
					} else {
						struct allocExtDesc *aed =
							(struct allocExtDesc *)
							(epos.bh->b_data);
						int len =
						    sizeof(struct allocExtDesc);

						aed->lengthAllocDescs =
						    cpu_to_le32(lenalloc);
						if (!UDF_QUERY_FLAG(sb,
							UDF_FLAG_STRICT) ||
						    sbi->s_udfrev >= 0x0201)
							len += lenalloc;

						udf_update_tag(epos.bh->b_data,
								len);
						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) {
				iinfo->i_lenAlloc = 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));
		}
	}
	iinfo->i_lenExtents = 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	76	int adsize;
48d6d8ff	77	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	78
48d6d8ff MS	79	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB \|\|
48d6d8ff MS	80	inode->i_size == iinfo->i_lenExtents)
74584ae5 JK	81	return;
	82	/* Are we going to delete the file anyway? */
	83	if (inode->i_nlink == 0)
1da177e4	84	return;
1da177e4	85
48d6d8ff	86	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
1da177e4	87	adsize = sizeof(short_ad);
48d6d8ff	88	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
1da177e4 LT	89	adsize = sizeof(long_ad);
1da177e4 LT	90	else
74584ae5	91	BUG();
1da177e4	92
ff116fc8	93	/* Find the last extent in the file */
cb00ea35	94	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
1da177e4 LT	95	etype = netype;
1da177e4 LT	96	lbcount += elen;
74584ae5 JK	97	if (lbcount > inode->i_size) {
	98	if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)
	99	printk(KERN_WARNING
	100	"udf_truncate_tail_extent(): Too long "
	101	"extent after EOF in inode %u: i_size: "
	102	"%Ld lbcount: %Ld extent %u+%u\n",
	103	(unsigned)inode->i_ino,
	104	(long long)inode->i_size,
	105	(long long)lbcount,
	106	(unsigned)eloc.logicalBlockNum,
	107	(unsigned)elen);
1da177e4	108	nelen = elen - (lbcount - inode->i_size);
ff116fc8 JK	109	epos.offset -= adsize;
	110	extent_trunc(inode, &epos, eloc, etype, elen, nelen);
	111	epos.offset += adsize;
74584ae5 JK	112	if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1)
	113	printk(KERN_ERR "udf_truncate_tail_extent(): "
	114	"Extent after EOF in inode %u.\n",
	115	(unsigned)inode->i_ino);
	116	break;
1da177e4 LT	117	}
1da177e4 LT	118	}
74584ae5 JK	119	/* This inode entry is in-memory only and thus we don't have to mark
74584ae5 JK	120	* the inode dirty */
48d6d8ff	121	iinfo->i_lenExtents = inode->i_size;
74584ae5 JK	122	brelse(epos.bh);
	123	}
	124
	125	void udf_discard_prealloc(struct inode *inode)
	126	{
cb00ea35	127	struct extent_position epos = { NULL, 0, {0, 0} };
74584ae5 JK	128	kernel_lb_addr eloc;
	129	uint32_t elen;
	130	uint64_t lbcount = 0;
	131	int8_t etype = -1, netype;
	132	int adsize;
48d6d8ff	133	struct udf_inode_info *iinfo = UDF_I(inode);
74584ae5	134
48d6d8ff MS	135	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB \|\|
48d6d8ff MS	136	inode->i_size == iinfo->i_lenExtents)
74584ae5 JK	137	return;
74584ae5 JK	138
48d6d8ff	139	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
74584ae5	140	adsize = sizeof(short_ad);
48d6d8ff	141	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
74584ae5 JK	142	adsize = sizeof(long_ad);
	143	else
	144	adsize = 0;
	145
48d6d8ff	146	epos.block = iinfo->i_location;
74584ae5 JK	147
	148	/* Find the last extent in the file */
	149	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
	150	etype = netype;
	151	lbcount += elen;
	152	}
ff116fc8 JK	153	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
ff116fc8 JK	154	epos.offset -= adsize;
1da177e4	155	lbcount -= elen;
ff116fc8	156	extent_trunc(inode, &epos, eloc, etype, elen, 0);
74584ae5	157	if (!epos.bh) {
48d6d8ff	158	iinfo->i_lenAlloc =
4b11111a MS	159	epos.offset -
4b11111a MS	160	udf_file_entry_alloc_offset(inode);
1da177e4	161	mark_inode_dirty(inode);
74584ae5	162	} else {
cb00ea35	163	struct allocExtDesc *aed =
28de7948	164	(struct allocExtDesc *)(epos.bh->b_data);
cb00ea35	165	aed->lengthAllocDescs =
28de7948 CG	166	cpu_to_le32(epos.offset -
	167	sizeof(struct allocExtDesc));
	168	if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) \|\|
6c79e987	169	UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
ff116fc8	170	udf_update_tag(epos.bh->b_data, epos.offset);
1da177e4	171	else
cb00ea35 CG	172	udf_update_tag(epos.bh->b_data,
cb00ea35 CG	173	sizeof(struct allocExtDesc));
ff116fc8	174	mark_buffer_dirty_inode(epos.bh, inode);
1da177e4 LT	175	}
1da177e4 LT	176	}
74584ae5 JK	177	/* This inode entry is in-memory only and thus we don't have to mark
74584ae5 JK	178	* the inode dirty */
48d6d8ff	179	iinfo->i_lenExtents = lbcount;
3bf25cb4	180	brelse(epos.bh);
1da177e4 LT	181	}
1da177e4 LT	182
cb00ea35	183	void udf_truncate_extents(struct inode *inode)
1da177e4	184	{
ff116fc8	185	struct extent_position epos;
28de7948	186	kernel_lb_addr eloc, neloc = {};
ff116fc8	187	uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
1da177e4	188	int8_t etype;
31170b6a	189	struct super_block *sb = inode->i_sb;
6c79e987	190	struct udf_sb_info *sbi = UDF_SB(sb);
31170b6a	191	sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;
60448b1d	192	loff_t byte_offset;
1da177e4	193	int adsize;
48d6d8ff	194	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	195
48d6d8ff	196	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
1da177e4	197	adsize = sizeof(short_ad);
48d6d8ff	198	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
1da177e4 LT	199	adsize = sizeof(long_ad);
1da177e4 LT	200	else
ff116fc8	201	BUG();
1da177e4	202
ff116fc8	203	etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
28de7948 CG	204	byte_offset = (offset << sb->s_blocksize_bits) +
28de7948 CG	205	(inode->i_size & (sb->s_blocksize - 1));
cb00ea35	206	if (etype != -1) {
ff116fc8 JK	207	epos.offset -= adsize;
	208	extent_trunc(inode, &epos, eloc, etype, elen, byte_offset);
	209	epos.offset += adsize;
60448b1d	210	if (byte_offset)
ff116fc8	211	lenalloc = epos.offset;
1da177e4	212	else
ff116fc8	213	lenalloc = epos.offset - adsize;
1da177e4	214
ff116fc8	215	if (!epos.bh)
1da177e4 LT	216	lenalloc -= udf_file_entry_alloc_offset(inode);
	217	else
	218	lenalloc -= sizeof(struct allocExtDesc);
	219
4b11111a MS	220	while ((etype = udf_current_aext(inode, &epos, &eloc,
4b11111a MS	221	&elen, 0)) != -1) {
cb00ea35	222	if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30)) {
ff116fc8	223	udf_write_aext(inode, &epos, neloc, nelen, 0);
cb00ea35	224	if (indirect_ext_len) {
ff116fc8 JK	225	/* We managed to free all extents in the
	226	* indirect extent - free it too */
	227	if (!epos.bh)
1da177e4	228	BUG();
cb00ea35 CG	229	udf_free_blocks(sb, inode, epos.block,
	230	0, indirect_ext_len);
	231	} else {
	232	if (!epos.bh) {
48d6d8ff	233	iinfo->i_lenAlloc =
4b11111a	234	lenalloc;
1da177e4	235	mark_inode_dirty(inode);
cb00ea35 CG	236	} else {
cb00ea35 CG	237	struct allocExtDesc *aed =
4b11111a MS	238	(struct allocExtDesc *)
	239	(epos.bh->b_data);
	240	int len =
	241	sizeof(struct allocExtDesc);
	242
cb00ea35 CG	243	aed->lengthAllocDescs =
cb00ea35 CG	244	cpu_to_le32(lenalloc);
4b11111a MS	245	if (!UDF_QUERY_FLAG(sb,
4b11111a MS	246	UDF_FLAG_STRICT) \|\|
6c79e987	247	sbi->s_udfrev >= 0x0201)
4b11111a MS	248	len += lenalloc;
	249
	250	udf_update_tag(epos.bh->b_data,
	251	len);
	252	mark_buffer_dirty_inode(
	253	epos.bh, inode);
1da177e4 LT	254	}
1da177e4 LT	255	}
ff116fc8 JK	256	brelse(epos.bh);
	257	epos.offset = sizeof(struct allocExtDesc);
	258	epos.block = eloc;
4b11111a MS	259	epos.bh = udf_tread(sb,
4b11111a MS	260	udf_get_lb_pblock(sb, eloc, 0));
1da177e4	261	if (elen)
4b11111a MS	262	indirect_ext_len =
4b11111a MS	263	(elen + sb->s_blocksize - 1) >>
28de7948	264	sb->s_blocksize_bits;
1da177e4	265	else
ff116fc8	266	indirect_ext_len = 1;
cb00ea35	267	} else {
4b11111a MS	268	extent_trunc(inode, &epos, eloc, etype,
4b11111a MS	269	elen, 0);
ff116fc8	270	epos.offset += adsize;
1da177e4 LT	271	}
	272	}
	273
cb00ea35	274	if (indirect_ext_len) {
ff116fc8	275	if (!epos.bh)
1da177e4	276	BUG();
cb00ea35 CG	277	udf_free_blocks(sb, inode, epos.block, 0,
	278	indirect_ext_len);
	279	} else {
	280	if (!epos.bh) {
48d6d8ff	281	iinfo->i_lenAlloc = lenalloc;
1da177e4	282	mark_inode_dirty(inode);
cb00ea35 CG	283	} else {
	284	struct allocExtDesc *aed =
	285	(struct allocExtDesc *)(epos.bh->b_data);
1da177e4	286	aed->lengthAllocDescs = cpu_to_le32(lenalloc);
28de7948	287	if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) \|\|
6c79e987	288	sbi->s_udfrev >= 0x0201)
cb00ea35	289	udf_update_tag(epos.bh->b_data,
4b11111a MS	290	lenalloc +
4b11111a MS	291	sizeof(struct allocExtDesc));
1da177e4	292	else
cb00ea35	293	udf_update_tag(epos.bh->b_data,
4b11111a	294	sizeof(struct allocExtDesc));
ff116fc8	295	mark_buffer_dirty_inode(epos.bh, inode);
1da177e4 LT	296	}
1da177e4 LT	297	}
cb00ea35 CG	298	} else if (inode->i_size) {
cb00ea35 CG	299	if (byte_offset) {
31170b6a JK	300	kernel_long_ad extent;
31170b6a JK	301
00a2b0f6 JK	302	/*
	303	* OK, there is not extent covering inode->i_size and
	304	* no extent above inode->i_size => truncate is
31170b6a	305	* extending the file by 'offset' blocks.
00a2b0f6	306	*/
28de7948	307	if ((!epos.bh &&
4b11111a MS	308	epos.offset ==
	309	udf_file_entry_alloc_offset(inode)) \|\|
	310	(epos.bh && epos.offset ==
	311	sizeof(struct allocExtDesc))) {
31170b6a JK	312	/* File has no extents at all or has empty last
	313	* indirect extent! Create a fake extent... */
	314	extent.extLocation.logicalBlockNum = 0;
	315	extent.extLocation.partitionReferenceNum = 0;
4b11111a MS	316	extent.extLength =
4b11111a MS	317	EXT_NOT_RECORDED_NOT_ALLOCATED;
cb00ea35	318	} else {
ff116fc8	319	epos.offset -= adsize;
31170b6a	320	etype = udf_next_aext(inode, &epos,
cb00ea35 CG	321	&extent.extLocation,
cb00ea35 CG	322	&extent.extLength, 0);
31170b6a	323	extent.extLength \|= etype << 30;
1da177e4	324	}
cb00ea35	325	udf_extend_file(inode, &epos, &extent,
4b11111a MS	326	offset +
	327	((inode->i_size &
	328	(sb->s_blocksize - 1)) != 0));
1da177e4 LT	329	}
1da177e4 LT	330	}
48d6d8ff	331	iinfo->i_lenExtents = inode->i_size;
1da177e4	332
3bf25cb4	333	brelse(epos.bh);
1da177e4	334	}