[linux-2.6-block.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 "udf_i.h"
#include "udf_sb.h"

static void extent_trunc(struct inode *inode, struct extent_position *epos,
			 struct kernel_lb_addr *eloc, int8_t etype, uint32_t elen,
			 uint32_t nelen)
{
	struct 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) {
			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 = {};
	struct 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(struct short_ad);
	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(struct 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)
				udf_warn(inode->i_sb,
					 "Too long extent after EOF in inode %u: i_size: %lld lbcount: %lld 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)
				udf_err(inode->i_sb,
					"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 = {};
	struct extent_position prev_epos = {};
	struct kernel_lb_addr eloc;
	uint32_t elen;
	uint64_t lbcount = 0;
	int8_t etype = -1;
	struct udf_inode_info *iinfo = UDF_I(inode);
	int bsize = 1 << inode->i_blkbits;

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

	epos.block = iinfo->i_location;

	/* Find the last extent in the file */
	while (udf_next_aext(inode, &epos, &eloc, &elen, 0) != -1) {
		brelse(prev_epos.bh);
		prev_epos = epos;
		if (prev_epos.bh)
			get_bh(prev_epos.bh);

		etype = udf_next_aext(inode, &epos, &eloc, &elen, 1);
		lbcount += elen;
	}
	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
		lbcount -= elen;
		udf_delete_aext(inode, prev_epos);
		udf_free_blocks(inode->i_sb, inode, &eloc, 0,
				DIV_ROUND_UP(elen, 1 << inode->i_blkbits));
	}
	/* 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);
	brelse(prev_epos.bh);
}

static void udf_update_alloc_ext_desc(struct inode *inode,
				      struct extent_position *epos,
				      u32 lenalloc)
{
	struct super_block *sb = inode->i_sb;
	struct udf_sb_info *sbi = UDF_SB(sb);

	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);
}

/*
 * Truncate extents of inode to inode->i_size. This function can be used only
 * for making file shorter. For making file longer, udf_extend_file() has to
 * be used.
 */
int udf_truncate_extents(struct inode *inode)
{
	struct extent_position epos;
	struct 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;
	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(struct short_ad);
	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(struct 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) {
		/* We should extend the file? */
		WARN_ON(byte_offset);
		return 0;
	}
	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_ALLOCDESCS >> 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 */
				BUG_ON(!epos.bh);
				udf_free_blocks(sb, NULL, &epos.block,
						0, indirect_ext_len);
			} else if (!epos.bh) {
				iinfo->i_lenAlloc = lenalloc;
				mark_inode_dirty(inode);
			} else
				udf_update_alloc_ext_desc(inode,
						&epos, lenalloc);
			brelse(epos.bh);
			epos.offset = sizeof(struct allocExtDesc);
			epos.block = eloc;
			epos.bh = sb_bread(sb,
					udf_get_lb_pblock(sb, &eloc, 0));
			/* Error reading indirect block? */
			if (!epos.bh)
				return -EIO;
			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) {
		BUG_ON(!epos.bh);
		udf_free_blocks(sb, NULL, &epos.block, 0, indirect_ext_len);
	} else if (!epos.bh) {
		iinfo->i_lenAlloc = lenalloc;
		mark_inode_dirty(inode);
	} else
		udf_update_alloc_ext_desc(inode, &epos, lenalloc);
	iinfo->i_lenExtents = inode->i_size;

	brelse(epos.bh);
	return 0;
}
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>
1da177e4 LT	25
	26	#include "udf_i.h"
	27	#include "udf_sb.h"
	28
cb00ea35	29	static void extent_trunc(struct inode inode, struct extent_position epos,
97e961fd	30	struct kernel_lb_addr *eloc, int8_t etype, uint32_t elen,
cb00ea35	31	uint32_t nelen)
1da177e4	32	{
5ca4e4be	33	struct kernel_lb_addr neloc = {};
28de7948 CG	34	int last_block = (elen + inode->i_sb->s_blocksize - 1) >>
	35	inode->i_sb->s_blocksize_bits;
	36	int first_block = (nelen + inode->i_sb->s_blocksize - 1) >>
	37	inode->i_sb->s_blocksize_bits;
1da177e4	38
cb00ea35 CG	39	if (nelen) {
	40	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
	41	udf_free_blocks(inode->i_sb, inode, eloc, 0,
	42	last_block);
1da177e4	43	etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
cb00ea35	44	} else
97e961fd	45	neloc = *eloc;
1da177e4 LT	46	nelen = (etype << 30) \| nelen;
	47	}
	48
cb00ea35	49	if (elen != nelen) {
97e961fd	50	udf_write_aext(inode, epos, &neloc, nelen, 0);
b490bdd6	51	if (last_block > first_block) {
1da177e4 LT	52	if (etype == (EXT_RECORDED_ALLOCATED >> 30))
	53	mark_inode_dirty(inode);
	54
	55	if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
cb00ea35 CG	56	udf_free_blocks(inode->i_sb, inode, eloc,
	57	first_block,
	58	last_block - first_block);
1da177e4 LT	59	}
	60	}
	61	}
	62
74584ae5 JK	63	/*
	64	* Truncate the last extent to match i_size. This function assumes
	65	* that preallocation extent is already truncated.
	66	*/
	67	void udf_truncate_tail_extent(struct inode *inode)
1da177e4	68	{
28de7948	69	struct extent_position epos = {};
5ca4e4be	70	struct kernel_lb_addr eloc;
ff116fc8	71	uint32_t elen, nelen;
1da177e4 LT	72	uint64_t lbcount = 0;
1da177e4 LT	73	int8_t etype = -1, netype;
1da177e4	74	int adsize;
48d6d8ff	75	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	76
48d6d8ff MS	77	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB \|\|
48d6d8ff MS	78	inode->i_size == iinfo->i_lenExtents)
74584ae5 JK	79	return;
	80	/* Are we going to delete the file anyway? */
	81	if (inode->i_nlink == 0)
1da177e4	82	return;
1da177e4	83
48d6d8ff	84	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
5ca4e4be	85	adsize = sizeof(struct short_ad);
48d6d8ff	86	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
5ca4e4be	87	adsize = sizeof(struct long_ad);
1da177e4	88	else
74584ae5	89	BUG();
1da177e4	90
ff116fc8	91	/* Find the last extent in the file */
cb00ea35	92	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
1da177e4 LT	93	etype = netype;
1da177e4 LT	94	lbcount += elen;
74584ae5 JK	95	if (lbcount > inode->i_size) {
74584ae5 JK	96	if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)
78ace70c JP	97	udf_warn(inode->i_sb,
	98	"Too long extent after EOF in inode %u: i_size: %lld lbcount: %lld extent %u+%u\n",
	99	(unsigned)inode->i_ino,
	100	(long long)inode->i_size,
	101	(long long)lbcount,
	102	(unsigned)eloc.logicalBlockNum,
	103	(unsigned)elen);
1da177e4	104	nelen = elen - (lbcount - inode->i_size);
ff116fc8	105	epos.offset -= adsize;
97e961fd	106	extent_trunc(inode, &epos, &eloc, etype, elen, nelen);
ff116fc8	107	epos.offset += adsize;
74584ae5	108	if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1)
78ace70c JP	109	udf_err(inode->i_sb,
	110	"Extent after EOF in inode %u\n",
	111	(unsigned)inode->i_ino);
74584ae5	112	break;
1da177e4 LT	113	}
1da177e4 LT	114	}
74584ae5 JK	115	/* This inode entry is in-memory only and thus we don't have to mark
74584ae5 JK	116	* the inode dirty */
48d6d8ff	117	iinfo->i_lenExtents = inode->i_size;
74584ae5 JK	118	brelse(epos.bh);
	119	}
	120
	121	void udf_discard_prealloc(struct inode *inode)
	122	{
cfe4c1b2 JK	123	struct extent_position epos = {};
cfe4c1b2 JK	124	struct extent_position prev_epos = {};
5ca4e4be	125	struct kernel_lb_addr eloc;
74584ae5 JK	126	uint32_t elen;
74584ae5 JK	127	uint64_t lbcount = 0;
1fb40763	128	int8_t etype = -1;
48d6d8ff	129	struct udf_inode_info *iinfo = UDF_I(inode);
6ad53f0f	130	int bsize = 1 << inode->i_blkbits;
74584ae5	131
48d6d8ff	132	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB \|\|
6ad53f0f	133	ALIGN(inode->i_size, bsize) == ALIGN(iinfo->i_lenExtents, bsize))
74584ae5 JK	134	return;
74584ae5 JK	135
48d6d8ff	136	epos.block = iinfo->i_location;
74584ae5 JK	137
74584ae5 JK	138	/* Find the last extent in the file */
1fb40763	139	while (udf_next_aext(inode, &epos, &eloc, &elen, 0) != -1) {
cfe4c1b2 JK	140	brelse(prev_epos.bh);
	141	prev_epos = epos;
	142	if (prev_epos.bh)
	143	get_bh(prev_epos.bh);
	144
	145	etype = udf_next_aext(inode, &epos, &eloc, &elen, 1);
74584ae5 JK	146	lbcount += elen;
74584ae5 JK	147	}
ff116fc8	148	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
1da177e4	149	lbcount -= elen;
cfe4c1b2 JK	150	udf_delete_aext(inode, prev_epos);
	151	udf_free_blocks(inode->i_sb, inode, &eloc, 0,
	152	DIV_ROUND_UP(elen, 1 << inode->i_blkbits));
1da177e4	153	}
74584ae5 JK	154	/* This inode entry is in-memory only and thus we don't have to mark
74584ae5 JK	155	* the inode dirty */
48d6d8ff	156	iinfo->i_lenExtents = lbcount;
3bf25cb4	157	brelse(epos.bh);
cfe4c1b2	158	brelse(prev_epos.bh);
1da177e4 LT	159	}
1da177e4 LT	160
456390de	161	static void udf_update_alloc_ext_desc(struct inode *inode,
	162	struct extent_position *epos,
	163	u32 lenalloc)
	164	{
	165	struct super_block *sb = inode->i_sb;
	166	struct udf_sb_info *sbi = UDF_SB(sb);
	167
	168	struct allocExtDesc aed = (struct allocExtDesc ) (epos->bh->b_data);
	169	int len = sizeof(struct allocExtDesc);
	170
	171	aed->lengthAllocDescs = cpu_to_le32(lenalloc);
	172	if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) \|\| sbi->s_udfrev >= 0x0201)
	173	len += lenalloc;
	174
	175	udf_update_tag(epos->bh->b_data, len);
	176	mark_buffer_dirty_inode(epos->bh, inode);
	177	}
	178
7e49b6f2 JK	179	/*
	180	* Truncate extents of inode to inode->i_size. This function can be used only
	181	* for making file shorter. For making file longer, udf_extend_file() has to
	182	* be used.
	183	*/
2b42be5e	184	int udf_truncate_extents(struct inode *inode)
1da177e4	185	{
ff116fc8	186	struct extent_position epos;
5ca4e4be	187	struct kernel_lb_addr eloc, neloc = {};
ff116fc8	188	uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
1da177e4	189	int8_t etype;
31170b6a JK	190	struct super_block *sb = inode->i_sb;
31170b6a JK	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)
5ca4e4be	197	adsize = sizeof(struct short_ad);
48d6d8ff	198	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
5ca4e4be	199	adsize = sizeof(struct long_ad);
1da177e4	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));
7e49b6f2 JK	206	if (etype == -1) {
	207	/* We should extend the file? */
	208	WARN_ON(byte_offset);
2b42be5e	209	return 0;
7e49b6f2 JK	210	}
	211	epos.offset -= adsize;
	212	extent_trunc(inode, &epos, &eloc, etype, elen, byte_offset);
	213	epos.offset += adsize;
	214	if (byte_offset)
	215	lenalloc = epos.offset;
	216	else
	217	lenalloc = epos.offset - adsize;
1da177e4	218
7e49b6f2 JK	219	if (!epos.bh)
	220	lenalloc -= udf_file_entry_alloc_offset(inode);
	221	else
	222	lenalloc -= sizeof(struct allocExtDesc);
31170b6a	223
7e49b6f2 JK	224	while ((etype = udf_current_aext(inode, &epos, &eloc,
7e49b6f2 JK	225	&elen, 0)) != -1) {
800552ce	226	if (etype == (EXT_NEXT_EXTENT_ALLOCDESCS >> 30)) {
7e49b6f2 JK	227	udf_write_aext(inode, &epos, &neloc, nelen, 0);
	228	if (indirect_ext_len) {
	229	/* We managed to free all extents in the
	230	* indirect extent - free it too */
	231	BUG_ON(!epos.bh);
17dc59ba	232	udf_free_blocks(sb, NULL, &epos.block,
7e49b6f2 JK	233	0, indirect_ext_len);
	234	} else if (!epos.bh) {
	235	iinfo->i_lenAlloc = lenalloc;
	236	mark_inode_dirty(inode);
	237	} else
	238	udf_update_alloc_ext_desc(inode,
	239	&epos, lenalloc);
	240	brelse(epos.bh);
	241	epos.offset = sizeof(struct allocExtDesc);
	242	epos.block = eloc;
101ee137	243	epos.bh = sb_bread(sb,
7e49b6f2	244	udf_get_lb_pblock(sb, &eloc, 0));
d3ca4651 JK	245	/* Error reading indirect block? */
d3ca4651 JK	246	if (!epos.bh)
2b42be5e	247	return -EIO;
7e49b6f2 JK	248	if (elen)
	249	indirect_ext_len =
	250	(elen + sb->s_blocksize - 1) >>
	251	sb->s_blocksize_bits;
	252	else
	253	indirect_ext_len = 1;
	254	} else {
	255	extent_trunc(inode, &epos, &eloc, etype, elen, 0);
	256	epos.offset += adsize;
1da177e4 LT	257	}
1da177e4 LT	258	}
7e49b6f2 JK	259
	260	if (indirect_ext_len) {
	261	BUG_ON(!epos.bh);
17dc59ba	262	udf_free_blocks(sb, NULL, &epos.block, 0, indirect_ext_len);
7e49b6f2 JK	263	} else if (!epos.bh) {
	264	iinfo->i_lenAlloc = lenalloc;
	265	mark_inode_dirty(inode);
	266	} else
	267	udf_update_alloc_ext_desc(inode, &epos, lenalloc);
48d6d8ff	268	iinfo->i_lenExtents = inode->i_size;
1da177e4	269
3bf25cb4	270	brelse(epos.bh);
2b42be5e	271	return 0;
1da177e4	272	}