remove pointers to the defunct UDF mailing list
[linux-2.6.git] / fs / udf / truncate.c
1 /*
2  * truncate.c
3  *
4  * PURPOSE
5  *      Truncate handling routines for the OSTA-UDF(tm) filesystem.
6  *
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 }