[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, offset, nelen = 0, lelen = 0, lenalloc;
	int8_t etype;
	int first_block = inode->i_size >> inode->i_sb->s_blocksize_bits;
	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);
	offset += (inode->i_size & (inode->i_sb->s_blocksize - 1));
	if (etype != -1)
	{
		extoffset -= adsize;
		extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, offset);
		extoffset += adsize;

		if (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 (offset)
		{
			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 + 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 + 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 | 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 };
128	uint32_t extoffset, elen, offset, nelen = 0, lelen = 0, lenalloc;
129	int8_t etype;
130	int first_block = inode->i_size >> inode->i_sb->s_blocksize_bits;
131	struct buffer_head *bh = NULL;
132	int adsize;
133
134	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
135	adsize = sizeof(short_ad);
136	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
137	adsize = sizeof(long_ad);
138	else
139	adsize = 0;
140
141	etype = inode_bmap(inode, first_block, &bloc, &extoffset, &eloc, &elen, &offset, &bh);
142	offset += (inode->i_size & (inode->i_sb->s_blocksize - 1));
143	if (etype != -1)
144	{
145	extoffset -= adsize;
146	extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, offset);
147	extoffset += adsize;
148
149	if (offset)
150	lenalloc = extoffset;
151	else
152	lenalloc = extoffset - adsize;
153
154	if (!bh)
155	lenalloc -= udf_file_entry_alloc_offset(inode);
156	else
157	lenalloc -= sizeof(struct allocExtDesc);
158
159	while ((etype = udf_current_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 0)) != -1)
160	{
161	if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30))
162	{
163	udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 0);
164	extoffset = 0;
165	if (lelen)
166	{
167	if (!bh)
168	BUG();
169	else
170	memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
171	udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
172	}
173	else
174	{
175	if (!bh)
176	{
177	UDF_I_LENALLOC(inode) = lenalloc;
178	mark_inode_dirty(inode);
179	}
180	else
181	{
182	struct allocExtDesc aed = (struct allocExtDesc )(bh->b_data);
183	aed->lengthAllocDescs = cpu_to_le32(lenalloc);
184	if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) \|\| UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
185	udf_update_tag(bh->b_data, lenalloc +
186	sizeof(struct allocExtDesc));
187	else
188	udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
189	mark_buffer_dirty_inode(bh, inode);
190	}
191	}
192
193	udf_release_data(bh);
194	extoffset = sizeof(struct allocExtDesc);
195	bloc = eloc;
196	bh = udf_tread(inode->i_sb, udf_get_lb_pblock(inode->i_sb, bloc, 0));
197	if (elen)
198	lelen = (elen + inode->i_sb->s_blocksize - 1) >>
199	inode->i_sb->s_blocksize_bits;
200	else
201	lelen = 1;
202	}
203	else
204	{
205	extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, 0);
206	extoffset += adsize;
207	}
208	}
209
210	if (lelen)
211	{
212	if (!bh)
213	BUG();
214	else
215	memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
216	udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
217	}
218	else
219	{
220	if (!bh)
221	{
222	UDF_I_LENALLOC(inode) = lenalloc;
223	mark_inode_dirty(inode);
224	}
225	else
226	{
227	struct allocExtDesc aed = (struct allocExtDesc )(bh->b_data);
228	aed->lengthAllocDescs = cpu_to_le32(lenalloc);
229	if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) \|\| UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
230	udf_update_tag(bh->b_data, lenalloc +
231	sizeof(struct allocExtDesc));
232	else
233	udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
234	mark_buffer_dirty_inode(bh, inode);
235	}
236	}
237	}
238	else if (inode->i_size)
239	{
240	if (offset)
241	{
242	extoffset -= adsize;
243	etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
244	if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
245	{
246	extoffset -= adsize;
247	elen = EXT_NOT_RECORDED_NOT_ALLOCATED \| (elen + offset);
248	udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0);
249	}
250	else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
251	{
252	kernel_lb_addr neloc = { 0, 0 };
253	extoffset -= adsize;
254	nelen = EXT_NOT_RECORDED_NOT_ALLOCATED \|
255	((elen + offset + inode->i_sb->s_blocksize - 1) &
256	~(inode->i_sb->s_blocksize - 1));
257	udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1);
258	udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) \| elen, &bh, 1);
259	}
260	else
261	{
262	if (elen & (inode->i_sb->s_blocksize - 1))
263	{
264	extoffset -= adsize;
265	elen = EXT_RECORDED_ALLOCATED \|
266	((elen + inode->i_sb->s_blocksize - 1) &
267	~(inode->i_sb->s_blocksize - 1));
268	udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 1);
269	}
270	memset(&eloc, 0x00, sizeof(kernel_lb_addr));
271	elen = EXT_NOT_RECORDED_NOT_ALLOCATED \| offset;
272	udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
273	}
274	}
275	}
276	UDF_I_LENEXTENTS(inode) = inode->i_size;
277
278	udf_release_data(bh);
279	}