[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, kernel_lb_addr bloc, int extoffset,
	kernel_lb_addr eloc, int8_t etype, uint32_t elen, struct buffer_head *bh, uint32_t nelen)
{
	kernel_lb_addr neloc = { 0, 0 };
	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, bloc, &extoffset, neloc, nelen, bh, 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);
		}
	}
}

void udf_discard_prealloc(struct inode * inode)
{
	kernel_lb_addr bloc, eloc;
	uint32_t extoffset = 0, elen, nelen;
	uint64_t lbcount = 0;
	int8_t etype = -1, netype;
	struct buffer_head *bh = NULL;
	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;

	bloc = UDF_I_LOCATION(inode);

	while ((netype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
	{
		etype = netype;
		lbcount += elen;
		if (lbcount > inode->i_size && lbcount - inode->i_size < inode->i_sb->s_blocksize)
		{
			nelen = elen - (lbcount - inode->i_size);
			extent_trunc(inode, bloc, extoffset-adsize, eloc, etype, elen, bh, nelen);
			lbcount = inode->i_size;
		}
	}
	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
	{
		extoffset -= adsize;
		lbcount -= elen;
		extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, 0);
		if (!bh)
		{
			UDF_I_LENALLOC(inode) = extoffset - udf_file_entry_alloc_offset(inode);
			mark_inode_dirty(inode);
		}
		else
		{
			struct allocExtDesc *aed = (struct allocExtDesc *)(bh->b_data);
			aed->lengthAllocDescs = cpu_to_le32(extoffset - sizeof(struct allocExtDesc));
			if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
				udf_update_tag(bh->b_data, extoffset);
			else
				udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
			mark_buffer_dirty_inode(bh, inode);
		}
	}
	UDF_I_LENEXTENTS(inode) = lbcount;

	udf_release_data(bh);
}

void udf_truncate_extents(struct inode * inode)
{
	kernel_lb_addr bloc, eloc, neloc = { 0, 0 };
	uint32_t extoffset, elen, nelen = 0, lelen = 0, lenalloc;
	int8_t etype;
	sector_t first_block = inode->i_size >> inode->i_sb->s_blocksize_bits, offset;
	loff_t byte_offset;
	struct buffer_head *bh = NULL;
	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
		adsize = 0;

	etype = inode_bmap(inode, first_block, &bloc, &extoffset, &eloc, &elen, &offset, &bh);
	byte_offset = (offset << inode->i_sb->s_blocksize_bits) + (inode->i_size & (inode->i_sb->s_blocksize-1));
	if (etype != -1)
	{
		extoffset -= adsize;
		extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, byte_offset);
		extoffset += adsize;

		if (byte_offset)
			lenalloc = extoffset;
		else
			lenalloc = extoffset - adsize;

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

		while ((etype = udf_current_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 0)) != -1)
		{
			if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30))
			{
				udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 0);
				extoffset = 0;
				if (lelen)
				{
					if (!bh)
						BUG();
					else
						memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
					udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
				}
				else
				{
					if (!bh)
					{
						UDF_I_LENALLOC(inode) = lenalloc;
						mark_inode_dirty(inode);
					}
					else
					{
						struct allocExtDesc *aed = (struct allocExtDesc *)(bh->b_data);
						aed->lengthAllocDescs = cpu_to_le32(lenalloc);
						if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
							udf_update_tag(bh->b_data, lenalloc +
								sizeof(struct allocExtDesc));
						else
							udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
						mark_buffer_dirty_inode(bh, inode);
					}
				}

				udf_release_data(bh);
				extoffset = sizeof(struct allocExtDesc);
				bloc = eloc;
				bh = udf_tread(inode->i_sb, udf_get_lb_pblock(inode->i_sb, bloc, 0));
				if (elen)
					lelen = (elen + inode->i_sb->s_blocksize - 1) >>
						inode->i_sb->s_blocksize_bits;
				else
					lelen = 1;
			}
			else
			{
				extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, 0);
				extoffset += adsize;
			}
		}

		if (lelen)
		{
			if (!bh)
				BUG();
			else
				memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
			udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
		}
		else
		{
			if (!bh)
			{
				UDF_I_LENALLOC(inode) = lenalloc;
				mark_inode_dirty(inode);
			}
			else
			{
				struct allocExtDesc *aed = (struct allocExtDesc *)(bh->b_data);
				aed->lengthAllocDescs = cpu_to_le32(lenalloc);
				if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
					udf_update_tag(bh->b_data, lenalloc +
						sizeof(struct allocExtDesc));
				else
					udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
				mark_buffer_dirty_inode(bh, inode);
			}
		}
	}
	else if (inode->i_size)
	{
		if (byte_offset)
		{
			/*
			 *  OK, there is not extent covering inode->i_size and
			 *  no extent above inode->i_size => truncate is
			 *  extending the file by 'offset'.
			 */
			if ((!bh && extoffset == udf_file_entry_alloc_offset(inode)) ||
			    (bh && extoffset == sizeof(struct allocExtDesc))) {
				/* File has no extents at all! */
				memset(&eloc, 0x00, sizeof(kernel_lb_addr));
				elen = EXT_NOT_RECORDED_NOT_ALLOCATED | byte_offset;
				udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
			}
			else {
				extoffset -= adsize;
				etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
				if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
				{
					extoffset -= adsize;
					elen = EXT_NOT_RECORDED_NOT_ALLOCATED | (elen + byte_offset);
					udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0);
				}
				else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
				{
					kernel_lb_addr neloc = { 0, 0 };
					extoffset -= adsize;
					nelen = EXT_NOT_RECORDED_NOT_ALLOCATED |
						((elen + byte_offset + inode->i_sb->s_blocksize - 1) &
						~(inode->i_sb->s_blocksize - 1));
					udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1);
					udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) | elen, &bh, 1);
				}
				else
				{
					if (elen & (inode->i_sb->s_blocksize - 1))
					{
						extoffset -= adsize;
						elen = EXT_RECORDED_ALLOCATED |
							((elen + inode->i_sb->s_blocksize - 1) &
							~(inode->i_sb->s_blocksize - 1));
						udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 1);
					}
					memset(&eloc, 0x00, sizeof(kernel_lb_addr));
					elen = EXT_NOT_RECORDED_NOT_ALLOCATED | byte_offset;
					udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
				}
			}
		}
	}
	UDF_I_LENEXTENTS(inode) = inode->i_size;

	udf_release_data(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
	31	static void extent_trunc(struct inode * inode, kernel_lb_addr bloc, int extoffset,
	32	kernel_lb_addr eloc, int8_t etype, uint32_t elen, struct buffer_head *bh, uint32_t nelen)
	33	{
	34	kernel_lb_addr neloc = { 0, 0 };
	35	int last_block = (elen + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits;
	36	int first_block = (nelen + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits;
	37
	38	if (nelen)
	39	{
	40	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
	41	{
	42	udf_free_blocks(inode->i_sb, inode, eloc, 0, last_block);
	43	etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
	44	}
	45	else
	46	neloc = eloc;
	47	nelen = (etype << 30) \| nelen;
	48	}
	49
	50	if (elen != nelen)
	51	{
	52	udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 0);
	53	if (last_block - first_block > 0)
	54	{
	55	if (etype == (EXT_RECORDED_ALLOCATED >> 30))
	56	mark_inode_dirty(inode);
	57
	58	if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
	59	udf_free_blocks(inode->i_sb, inode, eloc, first_block, last_block - first_block);
	60	}
	61	}
	62	}
	63
	64	void udf_discard_prealloc(struct inode * inode)
	65	{
	66	kernel_lb_addr bloc, eloc;
	67	uint32_t extoffset = 0, elen, nelen;
	68	uint64_t lbcount = 0;
	69	int8_t etype = -1, netype;
	70	struct buffer_head *bh = NULL;
71	int adsize;
72
73	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB \|\|
74	inode->i_size == UDF_I_LENEXTENTS(inode))
75	{
76	return;
77	}
78
79	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
80	adsize = sizeof(short_ad);
81	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
82	adsize = sizeof(long_ad);
83	else
84	adsize = 0;
85
86	bloc = UDF_I_LOCATION(inode);
87
88	while ((netype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
89	{
90	etype = netype;
91	lbcount += elen;
92	if (lbcount > inode->i_size && lbcount - inode->i_size < inode->i_sb->s_blocksize)
93	{
94	nelen = elen - (lbcount - inode->i_size);
95	extent_trunc(inode, bloc, extoffset-adsize, eloc, etype, elen, bh, nelen);
96	lbcount = inode->i_size;
97	}
98	}
99	if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
100	{
101	extoffset -= adsize;
102	lbcount -= elen;
103	extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, 0);
104	if (!bh)
105	{
106	UDF_I_LENALLOC(inode) = extoffset - udf_file_entry_alloc_offset(inode);
107	mark_inode_dirty(inode);
108	}
109	else
110	{
111	struct allocExtDesc aed = (struct allocExtDesc )(bh->b_data);
112	aed->lengthAllocDescs = cpu_to_le32(extoffset - sizeof(struct allocExtDesc));
113	if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) \|\| UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
114	udf_update_tag(bh->b_data, extoffset);
115	else
116	udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
117	mark_buffer_dirty_inode(bh, inode);
118	}
119	}
120	UDF_I_LENEXTENTS(inode) = lbcount;
121
122	udf_release_data(bh);
123	}
124
125	void udf_truncate_extents(struct inode * inode)
126	{
127	kernel_lb_addr bloc, eloc, neloc = { 0, 0 };
60448b1d	128	uint32_t extoffset, elen, nelen = 0, lelen = 0, lenalloc;
1da177e4	129	int8_t etype;
60448b1d JK	130	sector_t first_block = inode->i_size >> inode->i_sb->s_blocksize_bits, offset;
60448b1d JK	131	loff_t byte_offset;
1da177e4 LT	132	struct buffer_head *bh = NULL;
	133	int adsize;
	134
	135	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
	136	adsize = sizeof(short_ad);
	137	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
	138	adsize = sizeof(long_ad);
	139	else
	140	adsize = 0;
	141
	142	etype = inode_bmap(inode, first_block, &bloc, &extoffset, &eloc, &elen, &offset, &bh);
60448b1d	143	byte_offset = (offset << inode->i_sb->s_blocksize_bits) + (inode->i_size & (inode->i_sb->s_blocksize-1));
1da177e4 LT	144	if (etype != -1)
	145	{
	146	extoffset -= adsize;
60448b1d	147	extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, byte_offset);
1da177e4 LT	148	extoffset += adsize;
1da177e4 LT	149
60448b1d	150	if (byte_offset)
1da177e4 LT	151	lenalloc = extoffset;
	152	else
	153	lenalloc = extoffset - adsize;
	154
	155	if (!bh)
	156	lenalloc -= udf_file_entry_alloc_offset(inode);
	157	else
	158	lenalloc -= sizeof(struct allocExtDesc);
	159
	160	while ((etype = udf_current_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 0)) != -1)
	161	{
	162	if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30))
	163	{
	164	udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 0);
	165	extoffset = 0;
	166	if (lelen)
	167	{
	168	if (!bh)
	169	BUG();
	170	else
	171	memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
	172	udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
	173	}
	174	else
	175	{
	176	if (!bh)
	177	{
	178	UDF_I_LENALLOC(inode) = lenalloc;
	179	mark_inode_dirty(inode);
	180	}
	181	else
	182	{
	183	struct allocExtDesc aed = (struct allocExtDesc )(bh->b_data);
	184	aed->lengthAllocDescs = cpu_to_le32(lenalloc);
	185	if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) \|\| UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
	186	udf_update_tag(bh->b_data, lenalloc +
	187	sizeof(struct allocExtDesc));
	188	else
	189	udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
	190	mark_buffer_dirty_inode(bh, inode);
	191	}
	192	}
	193
	194	udf_release_data(bh);
	195	extoffset = sizeof(struct allocExtDesc);
	196	bloc = eloc;
	197	bh = udf_tread(inode->i_sb, udf_get_lb_pblock(inode->i_sb, bloc, 0));
	198	if (elen)
	199	lelen = (elen + inode->i_sb->s_blocksize - 1) >>
	200	inode->i_sb->s_blocksize_bits;
	201	else
	202	lelen = 1;
	203	}
	204	else
	205	{
	206	extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, 0);
	207	extoffset += adsize;
	208	}
	209	}
	210
	211	if (lelen)
	212	{
	213	if (!bh)
	214	BUG();
215	else
216	memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
217	udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
218	}
219	else
220	{
221	if (!bh)
222	{
223	UDF_I_LENALLOC(inode) = lenalloc;
224	mark_inode_dirty(inode);
225	}
226	else
227	{
228	struct allocExtDesc aed = (struct allocExtDesc )(bh->b_data);
229	aed->lengthAllocDescs = cpu_to_le32(lenalloc);
230	if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) \|\| UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
231	udf_update_tag(bh->b_data, lenalloc +
232	sizeof(struct allocExtDesc));
233	else
234	udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
235	mark_buffer_dirty_inode(bh, inode);
236	}
237	}
238	}
239	else if (inode->i_size)
240	{
60448b1d	241	if (byte_offset)
1da177e4	242	{
00a2b0f6 JK	243	/*
	244	* OK, there is not extent covering inode->i_size and
	245	* no extent above inode->i_size => truncate is
	246	* extending the file by 'offset'.
	247	*/
	248	if ((!bh && extoffset == udf_file_entry_alloc_offset(inode)) \|\|
	249	(bh && extoffset == sizeof(struct allocExtDesc))) {
	250	/* File has no extents at all! */
	251	memset(&eloc, 0x00, sizeof(kernel_lb_addr));
60448b1d	252	elen = EXT_NOT_RECORDED_NOT_ALLOCATED \| byte_offset;
00a2b0f6	253	udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
1da177e4	254	}
00a2b0f6	255	else {
1da177e4	256	extoffset -= adsize;
00a2b0f6 JK	257	etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
	258	if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
	259	{
	260	extoffset -= adsize;
60448b1d	261	elen = EXT_NOT_RECORDED_NOT_ALLOCATED \| (elen + byte_offset);
00a2b0f6 JK	262	udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0);
	263	}
	264	else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
1da177e4	265	{
00a2b0f6	266	kernel_lb_addr neloc = { 0, 0 };
1da177e4	267	extoffset -= adsize;
00a2b0f6	268	nelen = EXT_NOT_RECORDED_NOT_ALLOCATED \|
60448b1d	269	((elen + byte_offset + inode->i_sb->s_blocksize - 1) &
1da177e4	270	~(inode->i_sb->s_blocksize - 1));
00a2b0f6 JK	271	udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1);
	272	udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) \| elen, &bh, 1);
	273	}
	274	else
	275	{
	276	if (elen & (inode->i_sb->s_blocksize - 1))
	277	{
	278	extoffset -= adsize;
	279	elen = EXT_RECORDED_ALLOCATED \|
	280	((elen + inode->i_sb->s_blocksize - 1) &
	281	~(inode->i_sb->s_blocksize - 1));
	282	udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 1);
	283	}
	284	memset(&eloc, 0x00, sizeof(kernel_lb_addr));
60448b1d	285	elen = EXT_NOT_RECORDED_NOT_ALLOCATED \| byte_offset;
00a2b0f6	286	udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
1da177e4	287	}
1da177e4 LT	288	}
	289	}
	290	}
	291	UDF_I_LENEXTENTS(inode) = inode->i_size;
	292
	293	udf_release_data(bh);
	294	}