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review.evervolv.com / android_kernel_lge_hammerhead / ae40eb1ef30ab4120bd3c8b7e3da99ee53d27a23 / . / fs / udf / truncate.c
blob: 0abd66ce36ea042091bd6564ff17b003257a2d24 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]1/*
2 * truncate.c
3 *
4 * PURPOSE
5 * Truncate handling routines for the OSTA-UDF(tm) filesystem.
6 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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
31static 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
64void 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
125void 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 {
Jan Kara00a2b0f2006-08-15 13:56:26 +0200[diff] [blame]242 /*
243 * OK, there is not extent covering inode->i_size and
244 * no extent above inode->i_size => truncate is
245 * extending the file by 'offset'.
246 */
247 if ((!bh && extoffset == udf_file_entry_alloc_offset(inode)) ||
248 (bh && extoffset == sizeof(struct allocExtDesc))) {
249 /* File has no extents at all! */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]250 memset(&eloc, 0x00, sizeof(kernel_lb_addr));
251 elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset;
252 udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
253 }
Jan Kara00a2b0f2006-08-15 13:56:26 +0200[diff] [blame]254 else {
255 extoffset -= adsize;
256 etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
257 if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
258 {
259 extoffset -= adsize;
260 elen = EXT_NOT_RECORDED_NOT_ALLOCATED | (elen + offset);
261 udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0);
262 }
263 else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
264 {
265 kernel_lb_addr neloc = { 0, 0 };
266 extoffset -= adsize;
267 nelen = EXT_NOT_RECORDED_NOT_ALLOCATED |
268 ((elen + offset + inode->i_sb->s_blocksize - 1) &
269 ~(inode->i_sb->s_blocksize - 1));
270 udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1);
271 udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) | elen, &bh, 1);
272 }
273 else
274 {
275 if (elen & (inode->i_sb->s_blocksize - 1))
276 {
277 extoffset -= adsize;
278 elen = EXT_RECORDED_ALLOCATED |
279 ((elen + inode->i_sb->s_blocksize - 1) &
280 ~(inode->i_sb->s_blocksize - 1));
281 udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 1);
282 }
283 memset(&eloc, 0x00, sizeof(kernel_lb_addr));
284 elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset;
285 udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
286 }
287 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]288 }
289 }
290 UDF_I_LENEXTENTS(inode) = inode->i_size;
291
292 udf_release_data(bh);
293}