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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * truncate.c
4 *
5 * PURPOSE
6 * Truncate handling routines for the OSTA-UDF(tm) filesystem.
7 *
8 * COPYRIGHT
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>
21
22#include "udf_i.h"
23#include "udf_sb.h"
24
25static void extent_trunc(struct inode *inode, struct extent_position *epos,
26 struct kernel_lb_addr *eloc, int8_t etype, uint32_t elen,
27 uint32_t nelen)
28{
29 struct kernel_lb_addr neloc = {};
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;
34
35 if (nelen) {
36 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
37 udf_free_blocks(inode->i_sb, inode, eloc, 0,
38 last_block);
39 etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
40 } else
41 neloc = *eloc;
42 nelen = (etype << 30) | nelen;
43 }
44
45 if (elen != nelen) {
46 udf_write_aext(inode, epos, &neloc, nelen, 0);
47 if (last_block > first_block) {
48 if (etype == (EXT_RECORDED_ALLOCATED >> 30))
49 mark_inode_dirty(inode);
50
51 if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
52 udf_free_blocks(inode->i_sb, inode, eloc,
53 first_block,
54 last_block - first_block);
55 }
56 }
57}
58
59/*
60 * Truncate the last extent to match i_size. This function assumes
61 * that preallocation extent is already truncated.
62 */
63void udf_truncate_tail_extent(struct inode *inode)
64{
65 struct extent_position epos = {};
66 struct kernel_lb_addr eloc;
67 uint32_t elen, nelen;
68 uint64_t lbcount = 0;
69 int8_t etype = -1, netype;
70 int adsize;
71 struct udf_inode_info *iinfo = UDF_I(inode);
72 int ret;
73
74 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
75 inode->i_size == iinfo->i_lenExtents)
76 return;
77 /* Are we going to delete the file anyway? */
78 if (inode->i_nlink == 0)
79 return;
80
81 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
82 adsize = sizeof(struct short_ad);
83 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
84 adsize = sizeof(struct long_ad);
85 else
86 BUG();
87
88 /* Find the last extent in the file */
89 while (1) {
90 ret = udf_next_aext(inode, &epos, &eloc, &elen, &netype, 1);
91 if (ret <= 0)
92 break;
93 etype = netype;
94 lbcount += elen;
95 if (lbcount > inode->i_size) {
96 if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)
97 udf_warn(inode->i_sb,
98 "Too long extent after EOF in inode %u: i_size: %lld lbcount: %lld extent %u+%u\n",
99 (unsigned)inode->i_ino,
100 (long long)inode->i_size,
101 (long long)lbcount,
102 (unsigned)eloc.logicalBlockNum,
103 (unsigned)elen);
104 nelen = elen - (lbcount - inode->i_size);
105 epos.offset -= adsize;
106 extent_trunc(inode, &epos, &eloc, etype, elen, nelen);
107 epos.offset += adsize;
108 if (udf_next_aext(inode, &epos, &eloc, &elen,
109 &netype, 1) > 0)
110 udf_err(inode->i_sb,
111 "Extent after EOF in inode %u\n",
112 (unsigned)inode->i_ino);
113 break;
114 }
115 }
116 /* This inode entry is in-memory only and thus we don't have to mark
117 * the inode dirty */
118 if (ret == 0)
119 iinfo->i_lenExtents = inode->i_size;
120 brelse(epos.bh);
121}
122
123void udf_discard_prealloc(struct inode *inode)
124{
125 struct extent_position epos = {};
126 struct extent_position prev_epos = {};
127 struct kernel_lb_addr eloc;
128 uint32_t elen;
129 uint64_t lbcount = 0;
130 int8_t etype = -1;
131 struct udf_inode_info *iinfo = UDF_I(inode);
132 int bsize = i_blocksize(inode);
133 int8_t tmpetype = -1;
134 int ret;
135
136 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
137 ALIGN(inode->i_size, bsize) == ALIGN(iinfo->i_lenExtents, bsize))
138 return;
139
140 epos.block = iinfo->i_location;
141
142 /* Find the last extent in the file */
143 while (1) {
144 ret = udf_next_aext(inode, &epos, &eloc, &elen, &tmpetype, 0);
145 if (ret < 0)
146 goto out;
147 if (ret == 0)
148 break;
149 brelse(prev_epos.bh);
150 prev_epos = epos;
151 if (prev_epos.bh)
152 get_bh(prev_epos.bh);
153
154 ret = udf_next_aext(inode, &epos, &eloc, &elen, &etype, 1);
155 if (ret < 0)
156 goto out;
157 lbcount += elen;
158 }
159
160 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
161 lbcount -= elen;
162 udf_delete_aext(inode, prev_epos);
163 udf_free_blocks(inode->i_sb, inode, &eloc, 0,
164 DIV_ROUND_UP(elen, bsize));
165 }
166 /* This inode entry is in-memory only and thus we don't have to mark
167 * the inode dirty */
168 iinfo->i_lenExtents = lbcount;
169out:
170 brelse(epos.bh);
171 brelse(prev_epos.bh);
172}
173
174static void udf_update_alloc_ext_desc(struct inode *inode,
175 struct extent_position *epos,
176 u32 lenalloc)
177{
178 struct super_block *sb = inode->i_sb;
179 struct udf_sb_info *sbi = UDF_SB(sb);
180
181 struct allocExtDesc *aed = (struct allocExtDesc *) (epos->bh->b_data);
182 int len = sizeof(struct allocExtDesc);
183
184 aed->lengthAllocDescs = cpu_to_le32(lenalloc);
185 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) || sbi->s_udfrev >= 0x0201)
186 len += lenalloc;
187
188 udf_update_tag(epos->bh->b_data, len);
189 mark_buffer_dirty_inode(epos->bh, inode);
190}
191
192/*
193 * Truncate extents of inode to inode->i_size. This function can be used only
194 * for making file shorter. For making file longer, udf_extend_file() has to
195 * be used.
196 */
197int udf_truncate_extents(struct inode *inode)
198{
199 struct extent_position epos;
200 struct kernel_lb_addr eloc, neloc = {};
201 uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
202 int8_t etype;
203 struct super_block *sb = inode->i_sb;
204 sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;
205 loff_t byte_offset;
206 int adsize;
207 struct udf_inode_info *iinfo = UDF_I(inode);
208 int ret = 0;
209
210 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
211 adsize = sizeof(struct short_ad);
212 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
213 adsize = sizeof(struct long_ad);
214 else
215 BUG();
216
217 ret = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset, &etype);
218 if (ret < 0)
219 return ret;
220 byte_offset = (offset << sb->s_blocksize_bits) +
221 (inode->i_size & (sb->s_blocksize - 1));
222 if (ret == 0) {
223 /* We should extend the file? */
224 WARN_ON(byte_offset);
225 return 0;
226 }
227 epos.offset -= adsize;
228 extent_trunc(inode, &epos, &eloc, etype, elen, byte_offset);
229 epos.offset += adsize;
230 if (byte_offset)
231 lenalloc = epos.offset;
232 else
233 lenalloc = epos.offset - adsize;
234
235 if (!epos.bh)
236 lenalloc -= udf_file_entry_alloc_offset(inode);
237 else
238 lenalloc -= sizeof(struct allocExtDesc);
239
240 while ((ret = udf_current_aext(inode, &epos, &eloc,
241 &elen, &etype, 0)) > 0) {
242 if (etype == (EXT_NEXT_EXTENT_ALLOCDESCS >> 30)) {
243 udf_write_aext(inode, &epos, &neloc, nelen, 0);
244 if (indirect_ext_len) {
245 /* We managed to free all extents in the
246 * indirect extent - free it too */
247 BUG_ON(!epos.bh);
248 udf_free_blocks(sb, NULL, &epos.block,
249 0, indirect_ext_len);
250 } else if (!epos.bh) {
251 iinfo->i_lenAlloc = lenalloc;
252 mark_inode_dirty(inode);
253 } else
254 udf_update_alloc_ext_desc(inode,
255 &epos, lenalloc);
256 brelse(epos.bh);
257 epos.offset = sizeof(struct allocExtDesc);
258 epos.block = eloc;
259 epos.bh = sb_bread(sb,
260 udf_get_lb_pblock(sb, &eloc, 0));
261 /* Error reading indirect block? */
262 if (!epos.bh)
263 return -EIO;
264 if (elen)
265 indirect_ext_len =
266 (elen + sb->s_blocksize - 1) >>
267 sb->s_blocksize_bits;
268 else
269 indirect_ext_len = 1;
270 } else {
271 extent_trunc(inode, &epos, &eloc, etype, elen, 0);
272 epos.offset += adsize;
273 }
274 }
275
276 if (ret < 0) {
277 brelse(epos.bh);
278 return ret;
279 }
280
281 if (indirect_ext_len) {
282 BUG_ON(!epos.bh);
283 udf_free_blocks(sb, NULL, &epos.block, 0, indirect_ext_len);
284 } else if (!epos.bh) {
285 iinfo->i_lenAlloc = lenalloc;
286 mark_inode_dirty(inode);
287 } else
288 udf_update_alloc_ext_desc(inode, &epos, lenalloc);
289 iinfo->i_lenExtents = inode->i_size;
290
291 brelse(epos.bh);
292 return 0;
293}
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
26#include "udf_i.h"
27#include "udf_sb.h"
28
29static void extent_trunc(struct inode *inode, struct extent_position *epos,
30 struct kernel_lb_addr *eloc, int8_t etype, uint32_t elen,
31 uint32_t nelen)
32{
33 struct kernel_lb_addr neloc = {};
34 int last_block = (elen + inode->i_sb->s_blocksize - 1) >>
35 inode->i_sb->s_blocksize_bits;
36 int first_block = (nelen + inode->i_sb->s_blocksize - 1) >>
37 inode->i_sb->s_blocksize_bits;
38
39 if (nelen) {
40 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
41 udf_free_blocks(inode->i_sb, inode, eloc, 0,
42 last_block);
43 etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
44 } else
45 neloc = *eloc;
46 nelen = (etype << 30) | nelen;
47 }
48
49 if (elen != nelen) {
50 udf_write_aext(inode, epos, &neloc, nelen, 0);
51 if (last_block > first_block) {
52 if (etype == (EXT_RECORDED_ALLOCATED >> 30))
53 mark_inode_dirty(inode);
54
55 if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
56 udf_free_blocks(inode->i_sb, inode, eloc,
57 first_block,
58 last_block - first_block);
59 }
60 }
61}
62
63/*
64 * Truncate the last extent to match i_size. This function assumes
65 * that preallocation extent is already truncated.
66 */
67void udf_truncate_tail_extent(struct inode *inode)
68{
69 struct extent_position epos = {};
70 struct kernel_lb_addr eloc;
71 uint32_t elen, nelen;
72 uint64_t lbcount = 0;
73 int8_t etype = -1, netype;
74 int adsize;
75 struct udf_inode_info *iinfo = UDF_I(inode);
76
77 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
78 inode->i_size == iinfo->i_lenExtents)
79 return;
80 /* Are we going to delete the file anyway? */
81 if (inode->i_nlink == 0)
82 return;
83
84 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
85 adsize = sizeof(struct short_ad);
86 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
87 adsize = sizeof(struct long_ad);
88 else
89 BUG();
90
91 /* Find the last extent in the file */
92 while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
93 etype = netype;
94 lbcount += elen;
95 if (lbcount > inode->i_size) {
96 if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)
97 udf_warn(inode->i_sb,
98 "Too long extent after EOF in inode %u: i_size: %lld lbcount: %lld extent %u+%u\n",
99 (unsigned)inode->i_ino,
100 (long long)inode->i_size,
101 (long long)lbcount,
102 (unsigned)eloc.logicalBlockNum,
103 (unsigned)elen);
104 nelen = elen - (lbcount - inode->i_size);
105 epos.offset -= adsize;
106 extent_trunc(inode, &epos, &eloc, etype, elen, nelen);
107 epos.offset += adsize;
108 if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1)
109 udf_err(inode->i_sb,
110 "Extent after EOF in inode %u\n",
111 (unsigned)inode->i_ino);
112 break;
113 }
114 }
115 /* This inode entry is in-memory only and thus we don't have to mark
116 * the inode dirty */
117 iinfo->i_lenExtents = inode->i_size;
118 brelse(epos.bh);
119}
120
121void udf_discard_prealloc(struct inode *inode)
122{
123 struct extent_position epos = {};
124 struct extent_position prev_epos = {};
125 struct kernel_lb_addr eloc;
126 uint32_t elen;
127 uint64_t lbcount = 0;
128 int8_t etype = -1, netype;
129 struct udf_inode_info *iinfo = UDF_I(inode);
130 int bsize = 1 << inode->i_blkbits;
131
132 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB ||
133 ALIGN(inode->i_size, bsize) == ALIGN(iinfo->i_lenExtents, bsize))
134 return;
135
136 epos.block = iinfo->i_location;
137
138 /* Find the last extent in the file */
139 while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 0)) != -1) {
140 brelse(prev_epos.bh);
141 prev_epos = epos;
142 if (prev_epos.bh)
143 get_bh(prev_epos.bh);
144
145 etype = udf_next_aext(inode, &epos, &eloc, &elen, 1);
146 lbcount += elen;
147 }
148 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
149 lbcount -= elen;
150 udf_delete_aext(inode, prev_epos);
151 udf_free_blocks(inode->i_sb, inode, &eloc, 0,
152 DIV_ROUND_UP(elen, 1 << inode->i_blkbits));
153 }
154 /* This inode entry is in-memory only and thus we don't have to mark
155 * the inode dirty */
156 iinfo->i_lenExtents = lbcount;
157 brelse(epos.bh);
158 brelse(prev_epos.bh);
159}
160
161static void udf_update_alloc_ext_desc(struct inode *inode,
162 struct extent_position *epos,
163 u32 lenalloc)
164{
165 struct super_block *sb = inode->i_sb;
166 struct udf_sb_info *sbi = UDF_SB(sb);
167
168 struct allocExtDesc *aed = (struct allocExtDesc *) (epos->bh->b_data);
169 int len = sizeof(struct allocExtDesc);
170
171 aed->lengthAllocDescs = cpu_to_le32(lenalloc);
172 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) || sbi->s_udfrev >= 0x0201)
173 len += lenalloc;
174
175 udf_update_tag(epos->bh->b_data, len);
176 mark_buffer_dirty_inode(epos->bh, inode);
177}
178
179/*
180 * Truncate extents of inode to inode->i_size. This function can be used only
181 * for making file shorter. For making file longer, udf_extend_file() has to
182 * be used.
183 */
184int udf_truncate_extents(struct inode *inode)
185{
186 struct extent_position epos;
187 struct kernel_lb_addr eloc, neloc = {};
188 uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
189 int8_t etype;
190 struct super_block *sb = inode->i_sb;
191 sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;
192 loff_t byte_offset;
193 int adsize;
194 struct udf_inode_info *iinfo = UDF_I(inode);
195
196 if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
197 adsize = sizeof(struct short_ad);
198 else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
199 adsize = sizeof(struct long_ad);
200 else
201 BUG();
202
203 etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
204 byte_offset = (offset << sb->s_blocksize_bits) +
205 (inode->i_size & (sb->s_blocksize - 1));
206 if (etype == -1) {
207 /* We should extend the file? */
208 WARN_ON(byte_offset);
209 return 0;
210 }
211 epos.offset -= adsize;
212 extent_trunc(inode, &epos, &eloc, etype, elen, byte_offset);
213 epos.offset += adsize;
214 if (byte_offset)
215 lenalloc = epos.offset;
216 else
217 lenalloc = epos.offset - adsize;
218
219 if (!epos.bh)
220 lenalloc -= udf_file_entry_alloc_offset(inode);
221 else
222 lenalloc -= sizeof(struct allocExtDesc);
223
224 while ((etype = udf_current_aext(inode, &epos, &eloc,
225 &elen, 0)) != -1) {
226 if (etype == (EXT_NEXT_EXTENT_ALLOCDESCS >> 30)) {
227 udf_write_aext(inode, &epos, &neloc, nelen, 0);
228 if (indirect_ext_len) {
229 /* We managed to free all extents in the
230 * indirect extent - free it too */
231 BUG_ON(!epos.bh);
232 udf_free_blocks(sb, NULL, &epos.block,
233 0, indirect_ext_len);
234 } else if (!epos.bh) {
235 iinfo->i_lenAlloc = lenalloc;
236 mark_inode_dirty(inode);
237 } else
238 udf_update_alloc_ext_desc(inode,
239 &epos, lenalloc);
240 brelse(epos.bh);
241 epos.offset = sizeof(struct allocExtDesc);
242 epos.block = eloc;
243 epos.bh = udf_tread(sb,
244 udf_get_lb_pblock(sb, &eloc, 0));
245 /* Error reading indirect block? */
246 if (!epos.bh)
247 return -EIO;
248 if (elen)
249 indirect_ext_len =
250 (elen + sb->s_blocksize - 1) >>
251 sb->s_blocksize_bits;
252 else
253 indirect_ext_len = 1;
254 } else {
255 extent_trunc(inode, &epos, &eloc, etype, elen, 0);
256 epos.offset += adsize;
257 }
258 }
259
260 if (indirect_ext_len) {
261 BUG_ON(!epos.bh);
262 udf_free_blocks(sb, NULL, &epos.block, 0, indirect_ext_len);
263 } else if (!epos.bh) {
264 iinfo->i_lenAlloc = lenalloc;
265 mark_inode_dirty(inode);
266 } else
267 udf_update_alloc_ext_desc(inode, &epos, lenalloc);
268 iinfo->i_lenExtents = inode->i_size;
269
270 brelse(epos.bh);
271 return 0;
272}