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

/*
 * directory.c
 *
 * PURPOSE
 *	Directory related functions
 *
 * 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.
 */

#include "udfdecl.h"
#include "udf_i.h"

#include <linux/fs.h>
#include <linux/string.h>
#include <linux/buffer_head.h>

#if 0
static uint8_t *udf_filead_read(struct inode *dir, uint8_t *tmpad,
				uint8_t ad_size, kernel_lb_addr fe_loc,
				int *pos, int *offset, struct buffer_head **bh,
				int *error)
{
	int loffset = *offset;
	int block;
	uint8_t *ad;
	int remainder;

	*error = 0;

	ad = (uint8_t *)(*bh)->b_data + *offset;
	*offset += ad_size;

	if (!ad) {
		brelse(*bh);
		*error = 1;
		return NULL;
	}

	if (*offset == dir->i_sb->s_blocksize) {
		brelse(*bh);
		block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
		if (!block)
			return NULL;
		*bh = udf_tread(dir->i_sb, block);
		if (!*bh)
			return NULL;
	} else if (*offset > dir->i_sb->s_blocksize) {
		ad = tmpad;

		remainder = dir->i_sb->s_blocksize - loffset;
		memcpy((uint8_t *)ad, (*bh)->b_data + loffset, remainder);

		brelse(*bh);
		block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
		if (!block)
			return NULL;
		(*bh) = udf_tread(dir->i_sb, block);
		if (!*bh)
			return NULL;

		memcpy((uint8_t *)ad + remainder, (*bh)->b_data,
			ad_size - remainder);
		*offset = ad_size - remainder;
	}

	return ad;
}
#endif

struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t *nf_pos,
					 struct udf_fileident_bh *fibh,
					 struct fileIdentDesc *cfi,
					 struct extent_position *epos,
					 kernel_lb_addr *eloc, uint32_t *elen,
					 sector_t *offset)
{
	struct fileIdentDesc *fi;
	int i, num, block;
	struct buffer_head *tmp, *bha[16];

	fibh->soffset = fibh->eoffset;

	if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB) {
		fi = udf_get_fileident(UDF_I_DATA(dir) -
				       (UDF_I_EFE(dir) ?
					sizeof(struct extendedFileEntry) :
					sizeof(struct fileEntry)),
				       dir->i_sb->s_blocksize,
				       &(fibh->eoffset));
		if (!fi)
			return NULL;

		*nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);

		memcpy((uint8_t *)cfi, (uint8_t *)fi,
		       sizeof(struct fileIdentDesc));

		return fi;
	}

	if (fibh->eoffset == dir->i_sb->s_blocksize) {
		int lextoffset = epos->offset;
		unsigned char blocksize_bits = dir->i_sb->s_blocksize_bits;

		if (udf_next_aext(dir, epos, eloc, elen, 1) !=
		    (EXT_RECORDED_ALLOCATED >> 30))
			return NULL;

		block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);

		(*offset)++;

		if ((*offset << blocksize_bits) >= *elen)
			*offset = 0;
		else
			epos->offset = lextoffset;

		brelse(fibh->sbh);
		fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
		if (!fibh->sbh)
			return NULL;
		fibh->soffset = fibh->eoffset = 0;

		if (!(*offset & ((16 >> (blocksize_bits - 9)) - 1))) {
			i = 16 >> (blocksize_bits - 9);
			if (i + *offset > (*elen >> blocksize_bits))
				i = (*elen >> blocksize_bits)-*offset;
			for (num = 0; i > 0; i--) {
				block = udf_get_lb_pblock(dir->i_sb, *eloc,
							  *offset + i);
				tmp = udf_tgetblk(dir->i_sb, block);
				if (tmp && !buffer_uptodate(tmp) &&
						!buffer_locked(tmp))
					bha[num++] = tmp;
				else
					brelse(tmp);
			}
			if (num) {
				ll_rw_block(READA, num, bha);
				for (i = 0; i < num; i++)
					brelse(bha[i]);
			}
		}
	} else if (fibh->sbh != fibh->ebh) {
		brelse(fibh->sbh);
		fibh->sbh = fibh->ebh;
	}

	fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
			       &(fibh->eoffset));

	if (!fi)
		return NULL;

	*nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);

	if (fibh->eoffset <= dir->i_sb->s_blocksize) {
		memcpy((uint8_t *)cfi, (uint8_t *)fi,
		       sizeof(struct fileIdentDesc));
	} else if (fibh->eoffset > dir->i_sb->s_blocksize) {
		int lextoffset = epos->offset;

		if (udf_next_aext(dir, epos, eloc, elen, 1) !=
		    (EXT_RECORDED_ALLOCATED >> 30))
			return NULL;

		block = udf_get_lb_pblock(dir->i_sb, *eloc, *offset);

		(*offset)++;

		if ((*offset << dir->i_sb->s_blocksize_bits) >= *elen)
			*offset = 0;
		else
			epos->offset = lextoffset;

		fibh->soffset -= dir->i_sb->s_blocksize;
		fibh->eoffset -= dir->i_sb->s_blocksize;

		fibh->ebh = udf_tread(dir->i_sb, block);
		if (!fibh->ebh)
			return NULL;

		if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
			int fi_len;

			memcpy((uint8_t *)cfi, (uint8_t *)fi, -fibh->soffset);
			memcpy((uint8_t *)cfi - fibh->soffset,
			       fibh->ebh->b_data,
			       sizeof(struct fileIdentDesc) + fibh->soffset);

			fi_len = (sizeof(struct fileIdentDesc) +
				  cfi->lengthFileIdent +
				  le16_to_cpu(cfi->lengthOfImpUse) + 3) & ~3;

			*nf_pos += (fi_len - (fibh->eoffset - fibh->soffset))
					>> 2;
			fibh->eoffset = fibh->soffset + fi_len;
		} else {
			memcpy((uint8_t *)cfi, (uint8_t *)fi,
			       sizeof(struct fileIdentDesc));
		}
	}
	return fi;
}

struct fileIdentDesc *udf_get_fileident(void *buffer, int bufsize, int *offset)
{
	struct fileIdentDesc *fi;
	int lengthThisIdent;
	uint8_t *ptr;
	int padlen;

	if ((!buffer) || (!offset)) {
		udf_debug("invalidparms\n, buffer=%p, offset=%p\n", buffer,
			  offset);
		return NULL;
	}

	ptr = buffer;

	if ((*offset > 0) && (*offset < bufsize))
		ptr += *offset;
	fi = (struct fileIdentDesc *)ptr;
	if (le16_to_cpu(fi->descTag.tagIdent) != TAG_IDENT_FID) {
		udf_debug("0x%x != TAG_IDENT_FID\n",
			  le16_to_cpu(fi->descTag.tagIdent));
		udf_debug("offset: %u sizeof: %lu bufsize: %u\n",
			  *offset, (unsigned long)sizeof(struct fileIdentDesc),
			  bufsize);
		return NULL;
	}
	if ((*offset + sizeof(struct fileIdentDesc)) > bufsize)
		lengthThisIdent = sizeof(struct fileIdentDesc);
	else
		lengthThisIdent = sizeof(struct fileIdentDesc) +
			fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);

	/* we need to figure padding, too! */
	padlen = lengthThisIdent % UDF_NAME_PAD;
	if (padlen)
		lengthThisIdent += (UDF_NAME_PAD - padlen);
	*offset = *offset + lengthThisIdent;

	return fi;
}

#if 0
static extent_ad *udf_get_fileextent(void *buffer, int bufsize, int *offset)
{
	extent_ad *ext;
	struct fileEntry *fe;
	uint8_t *ptr;

	if ((!buffer) || (!offset)) {
		printk(KERN_ERR "udf: udf_get_fileextent() invalidparms\n");
		return NULL;
	}

	fe = (struct fileEntry *)buffer;

	if (le16_to_cpu(fe->descTag.tagIdent) != TAG_IDENT_FE) {
		udf_debug("0x%x != TAG_IDENT_FE\n",
			  le16_to_cpu(fe->descTag.tagIdent));
		return NULL;
	}

	ptr = (uint8_t *)(fe->extendedAttr) +
		le32_to_cpu(fe->lengthExtendedAttr);

	if ((*offset > 0) && (*offset < le32_to_cpu(fe->lengthAllocDescs)))
		ptr += *offset;

	ext = (extent_ad *)ptr;

	*offset = *offset + sizeof(extent_ad);
	return ext;
}
#endif

short_ad *udf_get_fileshortad(uint8_t *ptr, int maxoffset, int *offset,
			      int inc)
{
	short_ad *sa;

	if ((!ptr) || (!offset)) {
		printk(KERN_ERR "udf: udf_get_fileshortad() invalidparms\n");
		return NULL;
	}

	if ((*offset < 0) || ((*offset + sizeof(short_ad)) > maxoffset))
		return NULL;
	else {
		sa = (short_ad *)ptr;
		if (sa->extLength == 0)
			return NULL;
	}

	if (inc)
		*offset += sizeof(short_ad);
	return sa;
}

long_ad *udf_get_filelongad(uint8_t *ptr, int maxoffset, int *offset, int inc)
{
	long_ad *la;

	if ((!ptr) || (!offset)) {
		printk(KERN_ERR "udf: udf_get_filelongad() invalidparms\n");
		return NULL;
	}

	if ((*offset < 0) || ((*offset + sizeof(long_ad)) > maxoffset))
		return NULL;
	else {
		la = (long_ad *)ptr;
		if (la->extLength == 0)
			return NULL;
	}

	if (inc)
		*offset += sizeof(long_ad);
	return la;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* directory.c
	3	*
	4	* PURPOSE
	5	* Directory related functions
	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
	14	#include "udfdecl.h"
	15	#include "udf_i.h"
	16
	17	#include <linux/fs.h>
	18	#include <linux/string.h>
	19	#include <linux/buffer_head.h>
	20
	21	#if 0
4b11111a	22	static uint8_t udf_filead_read(struct inode dir, uint8_t *tmpad,
cb00ea35 CG	23	uint8_t ad_size, kernel_lb_addr fe_loc,
	24	int pos, int offset, struct buffer_head **bh,
	25	int *error)
1da177e4 LT	26	{
	27	int loffset = *offset;
	28	int block;
	29	uint8_t *ad;
	30	int remainder;
	31
	32	*error = 0;
	33
28de7948	34	ad = (uint8_t )(bh)->b_data + *offset;
1da177e4 LT	35	*offset += ad_size;
1da177e4 LT	36
cb00ea35	37	if (!ad) {
3bf25cb4	38	brelse(*bh);
1da177e4 LT	39	*error = 1;
	40	return NULL;
	41	}
	42
cb00ea35	43	if (*offset == dir->i_sb->s_blocksize) {
3bf25cb4	44	brelse(*bh);
1da177e4 LT	45	block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
	46	if (!block)
	47	return NULL;
4b11111a MS	48	*bh = udf_tread(dir->i_sb, block);
4b11111a MS	49	if (!*bh)
1da177e4	50	return NULL;
cb00ea35	51	} else if (*offset > dir->i_sb->s_blocksize) {
1da177e4 LT	52	ad = tmpad;
	53
	54	remainder = dir->i_sb->s_blocksize - loffset;
28de7948	55	memcpy((uint8_t )ad, (bh)->b_data + loffset, remainder);
1da177e4	56
3bf25cb4	57	brelse(*bh);
1da177e4 LT	58	block = udf_get_lb_pblock(dir->i_sb, fe_loc, ++*pos);
	59	if (!block)
	60	return NULL;
4b11111a MS	61	(*bh) = udf_tread(dir->i_sb, block);
4b11111a MS	62	if (!*bh)
1da177e4 LT	63	return NULL;
1da177e4 LT	64
4b11111a MS	65	memcpy((uint8_t )ad + remainder, (bh)->b_data,
4b11111a MS	66	ad_size - remainder);
1da177e4 LT	67	*offset = ad_size - remainder;
1da177e4 LT	68	}
28de7948	69
1da177e4 LT	70	return ad;
	71	}
	72	#endif
	73
4b11111a	74	struct fileIdentDesc udf_fileident_read(struct inode dir, loff_t *nf_pos,
cb00ea35 CG	75	struct udf_fileident_bh *fibh,
	76	struct fileIdentDesc *cfi,
	77	struct extent_position *epos,
4b11111a MS	78	kernel_lb_addr eloc, uint32_t elen,
4b11111a MS	79	sector_t *offset)
1da177e4 LT	80	{
	81	struct fileIdentDesc *fi;
	82	int i, num, block;
cb00ea35	83	struct buffer_head tmp, bha[16];
1da177e4 LT	84
	85	fibh->soffset = fibh->eoffset;
	86
cb00ea35	87	if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB) {
1da177e4	88	fi = udf_get_fileident(UDF_I_DATA(dir) -
cb00ea35 CG	89	(UDF_I_EFE(dir) ?
	90	sizeof(struct extendedFileEntry) :
	91	sizeof(struct fileEntry)),
4b11111a MS	92	dir->i_sb->s_blocksize,
4b11111a MS	93	&(fibh->eoffset));
1da177e4 LT	94	if (!fi)
	95	return NULL;
	96
	97	*nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);
	98
28de7948	99	memcpy((uint8_t )cfi, (uint8_t )fi,
cb00ea35	100	sizeof(struct fileIdentDesc));
1da177e4 LT	101
	102	return fi;
	103	}
	104
cb00ea35	105	if (fibh->eoffset == dir->i_sb->s_blocksize) {
ff116fc8	106	int lextoffset = epos->offset;
4b11111a	107	unsigned char blocksize_bits = dir->i_sb->s_blocksize_bits;
1da177e4	108
ff116fc8	109	if (udf_next_aext(dir, epos, eloc, elen, 1) !=
cb00ea35	110	(EXT_RECORDED_ALLOCATED >> 30))
1da177e4	111	return NULL;
1da177e4 LT	112
	113	block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
	114
cb00ea35	115	(*offset)++;
1da177e4	116
4b11111a	117	if ((offset << blocksize_bits) >= elen)
1da177e4 LT	118	*offset = 0;
1da177e4 LT	119	else
ff116fc8	120	epos->offset = lextoffset;
1da177e4	121
3bf25cb4	122	brelse(fibh->sbh);
4b11111a MS	123	fibh->sbh = fibh->ebh = udf_tread(dir->i_sb, block);
4b11111a MS	124	if (!fibh->sbh)
1da177e4 LT	125	return NULL;
	126	fibh->soffset = fibh->eoffset = 0;
	127
4b11111a MS	128	if (!(*offset & ((16 >> (blocksize_bits - 9)) - 1))) {
	129	i = 16 >> (blocksize_bits - 9);
	130	if (i + offset > (elen >> blocksize_bits))
	131	i = (elen >> blocksize_bits)-offset;
cb00ea35	132	for (num = 0; i > 0; i--) {
4b11111a MS	133	block = udf_get_lb_pblock(dir->i_sb, *eloc,
4b11111a MS	134	*offset + i);
1da177e4	135	tmp = udf_tgetblk(dir->i_sb, block);
4b11111a MS	136	if (tmp && !buffer_uptodate(tmp) &&
4b11111a MS	137	!buffer_locked(tmp))
1da177e4 LT	138	bha[num++] = tmp;
	139	else
	140	brelse(tmp);
	141	}
cb00ea35	142	if (num) {
1da177e4	143	ll_rw_block(READA, num, bha);
cb00ea35	144	for (i = 0; i < num; i++)
1da177e4 LT	145	brelse(bha[i]);
	146	}
	147	}
cb00ea35	148	} else if (fibh->sbh != fibh->ebh) {
3bf25cb4	149	brelse(fibh->sbh);
1da177e4 LT	150	fibh->sbh = fibh->ebh;
	151	}
	152
	153	fi = udf_get_fileident(fibh->sbh->b_data, dir->i_sb->s_blocksize,
cb00ea35	154	&(fibh->eoffset));
1da177e4 LT	155
	156	if (!fi)
	157	return NULL;
	158
	159	*nf_pos += ((fibh->eoffset - fibh->soffset) >> 2);
	160
cb00ea35	161	if (fibh->eoffset <= dir->i_sb->s_blocksize) {
28de7948	162	memcpy((uint8_t )cfi, (uint8_t )fi,
cb00ea35 CG	163	sizeof(struct fileIdentDesc));
cb00ea35 CG	164	} else if (fibh->eoffset > dir->i_sb->s_blocksize) {
ff116fc8	165	int lextoffset = epos->offset;
1da177e4	166
ff116fc8	167	if (udf_next_aext(dir, epos, eloc, elen, 1) !=
cb00ea35	168	(EXT_RECORDED_ALLOCATED >> 30))
1da177e4	169	return NULL;
1da177e4 LT	170
	171	block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
	172
cb00ea35	173	(*offset)++;
1da177e4 LT	174
	175	if ((offset << dir->i_sb->s_blocksize_bits) >= elen)
	176	*offset = 0;
	177	else
ff116fc8	178	epos->offset = lextoffset;
1da177e4 LT	179
	180	fibh->soffset -= dir->i_sb->s_blocksize;
	181	fibh->eoffset -= dir->i_sb->s_blocksize;
	182
4b11111a MS	183	fibh->ebh = udf_tread(dir->i_sb, block);
4b11111a MS	184	if (!fibh->ebh)
1da177e4 LT	185	return NULL;
1da177e4 LT	186
cb00ea35	187	if (sizeof(struct fileIdentDesc) > -fibh->soffset) {
1da177e4 LT	188	int fi_len;
1da177e4 LT	189
28de7948	190	memcpy((uint8_t )cfi, (uint8_t )fi, -fibh->soffset);
4b11111a MS	191	memcpy((uint8_t *)cfi - fibh->soffset,
4b11111a MS	192	fibh->ebh->b_data,
cb00ea35	193	sizeof(struct fileIdentDesc) + fibh->soffset);
1da177e4	194
4b11111a MS	195	fi_len = (sizeof(struct fileIdentDesc) +
4b11111a MS	196	cfi->lengthFileIdent +
28de7948	197	le16_to_cpu(cfi->lengthOfImpUse) + 3) & ~3;
1da177e4	198
4b11111a MS	199	*nf_pos += (fi_len - (fibh->eoffset - fibh->soffset))
4b11111a MS	200	>> 2;
1da177e4	201	fibh->eoffset = fibh->soffset + fi_len;
cb00ea35	202	} else {
28de7948	203	memcpy((uint8_t )cfi, (uint8_t )fi,
cb00ea35	204	sizeof(struct fileIdentDesc));
1da177e4 LT	205	}
	206	}
	207	return fi;
	208	}
	209
cb00ea35	210	struct fileIdentDesc udf_get_fileident(void buffer, int bufsize, int *offset)
1da177e4 LT	211	{
	212	struct fileIdentDesc *fi;
	213	int lengthThisIdent;
cb00ea35	214	uint8_t *ptr;
1da177e4 LT	215	int padlen;
1da177e4 LT	216
cb00ea35 CG	217	if ((!buffer) \|\| (!offset)) {
	218	udf_debug("invalidparms\n, buffer=%p, offset=%p\n", buffer,
	219	offset);
1da177e4 LT	220	return NULL;
	221	}
	222
	223	ptr = buffer;
	224
4b11111a	225	if ((offset > 0) && (offset < bufsize))
1da177e4	226	ptr += *offset;
cb00ea35 CG	227	fi = (struct fileIdentDesc *)ptr;
cb00ea35 CG	228	if (le16_to_cpu(fi->descTag.tagIdent) != TAG_IDENT_FID) {
1da177e4	229	udf_debug("0x%x != TAG_IDENT_FID\n",
cb00ea35	230	le16_to_cpu(fi->descTag.tagIdent));
1da177e4	231	udf_debug("offset: %u sizeof: %lu bufsize: %u\n",
cb00ea35 CG	232	*offset, (unsigned long)sizeof(struct fileIdentDesc),
cb00ea35 CG	233	bufsize);
1da177e4 LT	234	return NULL;
1da177e4 LT	235	}
4b11111a	236	if ((*offset + sizeof(struct fileIdentDesc)) > bufsize)
1da177e4	237	lengthThisIdent = sizeof(struct fileIdentDesc);
4b11111a	238	else
1da177e4	239	lengthThisIdent = sizeof(struct fileIdentDesc) +
28de7948	240	fi->lengthFileIdent + le16_to_cpu(fi->lengthOfImpUse);
1da177e4 LT	241
	242	/* we need to figure padding, too! */
	243	padlen = lengthThisIdent % UDF_NAME_PAD;
	244	if (padlen)
	245	lengthThisIdent += (UDF_NAME_PAD - padlen);
	246	offset = offset + lengthThisIdent;
	247
	248	return fi;
	249	}
	250
	251	#if 0
cb00ea35	252	static extent_ad udf_get_fileextent(void buffer, int bufsize, int *offset)
1da177e4	253	{
cb00ea35	254	extent_ad *ext;
1da177e4	255	struct fileEntry *fe;
cb00ea35	256	uint8_t *ptr;
1da177e4	257
cb00ea35	258	if ((!buffer) \|\| (!offset)) {
1da177e4 LT	259	printk(KERN_ERR "udf: udf_get_fileextent() invalidparms\n");
	260	return NULL;
	261	}
	262
	263	fe = (struct fileEntry *)buffer;
	264
cb00ea35	265	if (le16_to_cpu(fe->descTag.tagIdent) != TAG_IDENT_FE) {
1da177e4	266	udf_debug("0x%x != TAG_IDENT_FE\n",
cb00ea35	267	le16_to_cpu(fe->descTag.tagIdent));
1da177e4 LT	268	return NULL;
	269	}
	270
4b11111a MS	271	ptr = (uint8_t *)(fe->extendedAttr) +
4b11111a MS	272	le32_to_cpu(fe->lengthExtendedAttr);
1da177e4	273
4b11111a	274	if ((offset > 0) && (offset < le32_to_cpu(fe->lengthAllocDescs)))
1da177e4	275	ptr += *offset;
1da177e4	276
28de7948	277	ext = (extent_ad *)ptr;
1da177e4 LT	278
	279	offset = offset + sizeof(extent_ad);
	280	return ext;
	281	}
	282	#endif
	283
28de7948	284	short_ad udf_get_fileshortad(uint8_t ptr, int maxoffset, int *offset,
cb00ea35	285	int inc)
1da177e4 LT	286	{
	287	short_ad *sa;
	288
cb00ea35	289	if ((!ptr) \|\| (!offset)) {
1da177e4 LT	290	printk(KERN_ERR "udf: udf_get_fileshortad() invalidparms\n");
	291	return NULL;
	292	}
	293
cb00ea35	294	if ((offset < 0) \|\| ((offset + sizeof(short_ad)) > maxoffset))
1da177e4	295	return NULL;
4b11111a MS	296	else {
	297	sa = (short_ad *)ptr;
	298	if (sa->extLength == 0)
	299	return NULL;
	300	}
1da177e4 LT	301
	302	if (inc)
	303	*offset += sizeof(short_ad);
	304	return sa;
	305	}
	306
28de7948	307	long_ad udf_get_filelongad(uint8_t ptr, int maxoffset, int *offset, int inc)
1da177e4 LT	308	{
	309	long_ad *la;
	310
cb00ea35	311	if ((!ptr) \|\| (!offset)) {
1da177e4 LT	312	printk(KERN_ERR "udf: udf_get_filelongad() invalidparms\n");
	313	return NULL;
	314	}
	315
cb00ea35	316	if ((offset < 0) \|\| ((offset + sizeof(long_ad)) > maxoffset))
1da177e4	317	return NULL;
4b11111a MS	318	else {
	319	la = (long_ad *)ptr;
	320	if (la->extLength == 0)
	321	return NULL;
	322	}
1da177e4 LT	323
	324	if (inc)
	325	*offset += sizeof(long_ad);
	326	return la;
	327	}