[linux-block.git] / fs / udf / truncate.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * truncate.c
 *
 * PURPOSE
 *	Truncate handling routines for the OSTA-UDF(tm) filesystem.
 *
 * COPYRIGHT
 *  (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 = i_blocksize(inode);

	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, bsize));
	}
	/* 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
5ce34554	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* truncate.c
	4	*
	5	* PURPOSE
	6	* Truncate handling routines for the OSTA-UDF(tm) filesystem.
	7	*
1da177e4	8	* COPYRIGHT
1da177e4 LT	9	* (C) 1999-2004 Ben Fennema
	10	* (C) 1999 Stelias Computing Inc
	11	*
	12	* HISTORY
	13	*
	14	* 02/24/99 blf Created.
	15	*
	16	*/
	17
	18	#include "udfdecl.h"
	19	#include <linux/fs.h>
	20	#include <linux/mm.h>
1da177e4 LT	21
	22	#include "udf_i.h"
	23	#include "udf_sb.h"
	24
cb00ea35	25	static void extent_trunc(struct inode inode, struct extent_position epos,
97e961fd	26	struct kernel_lb_addr *eloc, int8_t etype, uint32_t elen,
cb00ea35	27	uint32_t nelen)
1da177e4	28	{
5ca4e4be	29	struct kernel_lb_addr neloc = {};
28de7948 CG	30	int last_block = (elen + inode->i_sb->s_blocksize - 1) >>
	31	inode->i_sb->s_blocksize_bits;
	32	int first_block = (nelen + inode->i_sb->s_blocksize - 1) >>
	33	inode->i_sb->s_blocksize_bits;
1da177e4	34
cb00ea35 CG	35	if (nelen) {
	36	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
	37	udf_free_blocks(inode->i_sb, inode, eloc, 0,
	38	last_block);
1da177e4	39	etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
cb00ea35	40	} else
97e961fd	41	neloc = *eloc;
1da177e4 LT	42	nelen = (etype << 30) \| nelen;
	43	}
	44
cb00ea35	45	if (elen != nelen) {
97e961fd	46	udf_write_aext(inode, epos, &neloc, nelen, 0);
b490bdd6	47	if (last_block > first_block) {
1da177e4 LT	48	if (etype == (EXT_RECORDED_ALLOCATED >> 30))
	49	mark_inode_dirty(inode);
	50
	51	if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
cb00ea35 CG	52	udf_free_blocks(inode->i_sb, inode, eloc,
	53	first_block,
	54	last_block - first_block);
1da177e4 LT	55	}
	56	}
	57	}
	58
74584ae5 JK	59	/*
	60	* Truncate the last extent to match i_size. This function assumes
	61	* that preallocation extent is already truncated.
	62	*/
	63	void udf_truncate_tail_extent(struct inode *inode)
1da177e4	64	{
28de7948	65	struct extent_position epos = {};
5ca4e4be	66	struct kernel_lb_addr eloc;
ff116fc8	67	uint32_t elen, nelen;
1da177e4 LT	68	uint64_t lbcount = 0;
1da177e4 LT	69	int8_t etype = -1, netype;
1da177e4	70	int adsize;
48d6d8ff	71	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	72
48d6d8ff MS	73	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB \|\|
48d6d8ff MS	74	inode->i_size == iinfo->i_lenExtents)
74584ae5 JK	75	return;
	76	/* Are we going to delete the file anyway? */
	77	if (inode->i_nlink == 0)
1da177e4	78	return;
1da177e4	79
48d6d8ff	80	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
5ca4e4be	81	adsize = sizeof(struct short_ad);
48d6d8ff	82	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
5ca4e4be	83	adsize = sizeof(struct long_ad);
1da177e4	84	else
74584ae5	85	BUG();
1da177e4	86
ff116fc8	87	/* Find the last extent in the file */
cb00ea35	88	while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
1da177e4 LT	89	etype = netype;
1da177e4 LT	90	lbcount += elen;
74584ae5 JK	91	if (lbcount > inode->i_size) {
74584ae5 JK	92	if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)
78ace70c JP	93	udf_warn(inode->i_sb,
	94	"Too long extent after EOF in inode %u: i_size: %lld lbcount: %lld extent %u+%u\n",
	95	(unsigned)inode->i_ino,
	96	(long long)inode->i_size,
	97	(long long)lbcount,
	98	(unsigned)eloc.logicalBlockNum,
	99	(unsigned)elen);
1da177e4	100	nelen = elen - (lbcount - inode->i_size);
ff116fc8	101	epos.offset -= adsize;
97e961fd	102	extent_trunc(inode, &epos, &eloc, etype, elen, nelen);
ff116fc8	103	epos.offset += adsize;
74584ae5	104	if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1)
78ace70c JP	105	udf_err(inode->i_sb,
	106	"Extent after EOF in inode %u\n",
	107	(unsigned)inode->i_ino);
74584ae5	108	break;
1da177e4 LT	109	}
1da177e4 LT	110	}
74584ae5 JK	111	/* This inode entry is in-memory only and thus we don't have to mark
74584ae5 JK	112	* the inode dirty */
48d6d8ff	113	iinfo->i_lenExtents = inode->i_size;
74584ae5 JK	114	brelse(epos.bh);
	115	}
	116
	117	void udf_discard_prealloc(struct inode *inode)
	118	{
cfe4c1b2 JK	119	struct extent_position epos = {};
cfe4c1b2 JK	120	struct extent_position prev_epos = {};
5ca4e4be	121	struct kernel_lb_addr eloc;
74584ae5 JK	122	uint32_t elen;
74584ae5 JK	123	uint64_t lbcount = 0;
1fb40763	124	int8_t etype = -1;
48d6d8ff	125	struct udf_inode_info *iinfo = UDF_I(inode);
f768dc3c	126	int bsize = i_blocksize(inode);
74584ae5	127
48d6d8ff	128	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB \|\|
6ad53f0f	129	ALIGN(inode->i_size, bsize) == ALIGN(iinfo->i_lenExtents, bsize))
74584ae5 JK	130	return;
74584ae5 JK	131
48d6d8ff	132	epos.block = iinfo->i_location;
74584ae5 JK	133
74584ae5 JK	134	/* Find the last extent in the file */
1fb40763	135	while (udf_next_aext(inode, &epos, &eloc, &elen, 0) != -1) {
cfe4c1b2 JK	136	brelse(prev_epos.bh);
	137	prev_epos = epos;
	138	if (prev_epos.bh)
	139	get_bh(prev_epos.bh);
	140
	141	etype = udf_next_aext(inode, &epos, &eloc, &elen, 1);
74584ae5 JK	142	lbcount += elen;
74584ae5 JK	143	}
ff116fc8	144	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
1da177e4	145	lbcount -= elen;
cfe4c1b2 JK	146	udf_delete_aext(inode, prev_epos);
cfe4c1b2 JK	147	udf_free_blocks(inode->i_sb, inode, &eloc, 0,
f768dc3c	148	DIV_ROUND_UP(elen, bsize));
1da177e4	149	}
74584ae5 JK	150	/* This inode entry is in-memory only and thus we don't have to mark
74584ae5 JK	151	* the inode dirty */
48d6d8ff	152	iinfo->i_lenExtents = lbcount;
3bf25cb4	153	brelse(epos.bh);
cfe4c1b2	154	brelse(prev_epos.bh);
1da177e4 LT	155	}
1da177e4 LT	156
456390de	157	static void udf_update_alloc_ext_desc(struct inode *inode,
	158	struct extent_position *epos,
	159	u32 lenalloc)
	160	{
	161	struct super_block *sb = inode->i_sb;
	162	struct udf_sb_info *sbi = UDF_SB(sb);
	163
	164	struct allocExtDesc aed = (struct allocExtDesc ) (epos->bh->b_data);
	165	int len = sizeof(struct allocExtDesc);
	166
	167	aed->lengthAllocDescs = cpu_to_le32(lenalloc);
	168	if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) \|\| sbi->s_udfrev >= 0x0201)
	169	len += lenalloc;
	170
	171	udf_update_tag(epos->bh->b_data, len);
	172	mark_buffer_dirty_inode(epos->bh, inode);
	173	}
	174
7e49b6f2 JK	175	/*
	176	* Truncate extents of inode to inode->i_size. This function can be used only
	177	* for making file shorter. For making file longer, udf_extend_file() has to
	178	* be used.
	179	*/
2b42be5e	180	int udf_truncate_extents(struct inode *inode)
1da177e4	181	{
ff116fc8	182	struct extent_position epos;
5ca4e4be	183	struct kernel_lb_addr eloc, neloc = {};
ff116fc8	184	uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
1da177e4	185	int8_t etype;
31170b6a JK	186	struct super_block *sb = inode->i_sb;
31170b6a JK	187	sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;
60448b1d	188	loff_t byte_offset;
1da177e4	189	int adsize;
48d6d8ff	190	struct udf_inode_info *iinfo = UDF_I(inode);
1da177e4	191
48d6d8ff	192	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
5ca4e4be	193	adsize = sizeof(struct short_ad);
48d6d8ff	194	else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
5ca4e4be	195	adsize = sizeof(struct long_ad);
1da177e4	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));
7e49b6f2 JK	202	if (etype == -1) {
	203	/* We should extend the file? */
	204	WARN_ON(byte_offset);
2b42be5e	205	return 0;
7e49b6f2 JK	206	}
	207	epos.offset -= adsize;
	208	extent_trunc(inode, &epos, &eloc, etype, elen, byte_offset);
	209	epos.offset += adsize;
	210	if (byte_offset)
	211	lenalloc = epos.offset;
	212	else
	213	lenalloc = epos.offset - adsize;
1da177e4	214
7e49b6f2 JK	215	if (!epos.bh)
	216	lenalloc -= udf_file_entry_alloc_offset(inode);
	217	else
	218	lenalloc -= sizeof(struct allocExtDesc);
31170b6a	219
7e49b6f2 JK	220	while ((etype = udf_current_aext(inode, &epos, &eloc,
7e49b6f2 JK	221	&elen, 0)) != -1) {
800552ce	222	if (etype == (EXT_NEXT_EXTENT_ALLOCDESCS >> 30)) {
7e49b6f2 JK	223	udf_write_aext(inode, &epos, &neloc, nelen, 0);
	224	if (indirect_ext_len) {
	225	/* We managed to free all extents in the
	226	* indirect extent - free it too */
	227	BUG_ON(!epos.bh);
17dc59ba	228	udf_free_blocks(sb, NULL, &epos.block,
7e49b6f2 JK	229	0, indirect_ext_len);
	230	} else if (!epos.bh) {
	231	iinfo->i_lenAlloc = lenalloc;
	232	mark_inode_dirty(inode);
	233	} else
	234	udf_update_alloc_ext_desc(inode,
	235	&epos, lenalloc);
	236	brelse(epos.bh);
	237	epos.offset = sizeof(struct allocExtDesc);
	238	epos.block = eloc;
101ee137	239	epos.bh = sb_bread(sb,
7e49b6f2	240	udf_get_lb_pblock(sb, &eloc, 0));
d3ca4651 JK	241	/* Error reading indirect block? */
d3ca4651 JK	242	if (!epos.bh)
2b42be5e	243	return -EIO;
7e49b6f2 JK	244	if (elen)
	245	indirect_ext_len =
	246	(elen + sb->s_blocksize - 1) >>
	247	sb->s_blocksize_bits;
	248	else
	249	indirect_ext_len = 1;
	250	} else {
	251	extent_trunc(inode, &epos, &eloc, etype, elen, 0);
	252	epos.offset += adsize;
1da177e4 LT	253	}
1da177e4 LT	254	}
7e49b6f2 JK	255
	256	if (indirect_ext_len) {
	257	BUG_ON(!epos.bh);
17dc59ba	258	udf_free_blocks(sb, NULL, &epos.block, 0, indirect_ext_len);
7e49b6f2 JK	259	} else if (!epos.bh) {
	260	iinfo->i_lenAlloc = lenalloc;
	261	mark_inode_dirty(inode);
	262	} else
	263	udf_update_alloc_ext_desc(inode, &epos, lenalloc);
48d6d8ff	264	iinfo->i_lenExtents = inode->i_size;
1da177e4	265
3bf25cb4	266	brelse(epos.bh);
2b42be5e	267	return 0;
1da177e4	268	}