5 * Truncate handling routines for the OSTA-UDF(tm) filesystem.
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.
13 * (C) 1999-2004 Ben Fennema
14 * (C) 1999 Stelias Computing Inc
18 * 02/24/99 blf Created.
25 #include <linux/udf_fs.h>
26 #include <linux/buffer_head.h>
31 static void extent_trunc(struct inode *inode, struct extent_position *epos,
32 kernel_lb_addr eloc, int8_t etype, uint32_t elen,
35 kernel_lb_addr neloc = {};
36 int last_block = (elen + inode->i_sb->s_blocksize - 1) >>
37 inode->i_sb->s_blocksize_bits;
38 int first_block = (nelen + inode->i_sb->s_blocksize - 1) >>
39 inode->i_sb->s_blocksize_bits;
42 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
43 udf_free_blocks(inode->i_sb, inode, eloc, 0,
45 etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
48 nelen = (etype << 30) | nelen;
52 udf_write_aext(inode, epos, neloc, nelen, 0);
53 if (last_block - first_block > 0) {
54 if (etype == (EXT_RECORDED_ALLOCATED >> 30))
55 mark_inode_dirty(inode);
57 if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
58 udf_free_blocks(inode->i_sb, inode, eloc,
60 last_block - first_block);
66 * Truncate the last extent to match i_size. This function assumes
67 * that preallocation extent is already truncated.
69 void udf_truncate_tail_extent(struct inode *inode)
71 struct extent_position epos = {};
75 int8_t etype = -1, netype;
78 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB ||
79 inode->i_size == UDF_I_LENEXTENTS(inode))
81 /* Are we going to delete the file anyway? */
82 if (inode->i_nlink == 0)
85 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
86 adsize = sizeof(short_ad);
87 else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
88 adsize = sizeof(long_ad);
92 /* Find the last extent in the file */
93 while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
96 if (lbcount > inode->i_size) {
97 if (lbcount - inode->i_size >= inode->i_sb->s_blocksize)
99 "udf_truncate_tail_extent(): Too long "
100 "extent after EOF in inode %u: i_size: "
101 "%Ld lbcount: %Ld extent %u+%u\n",
102 (unsigned)inode->i_ino,
103 (long long)inode->i_size,
105 (unsigned)eloc.logicalBlockNum,
107 nelen = elen - (lbcount - inode->i_size);
108 epos.offset -= adsize;
109 extent_trunc(inode, &epos, eloc, etype, elen, nelen);
110 epos.offset += adsize;
111 if (udf_next_aext(inode, &epos, &eloc, &elen, 1) != -1)
112 printk(KERN_ERR "udf_truncate_tail_extent(): "
113 "Extent after EOF in inode %u.\n",
114 (unsigned)inode->i_ino);
118 /* This inode entry is in-memory only and thus we don't have to mark
120 UDF_I_LENEXTENTS(inode) = inode->i_size;
124 void udf_discard_prealloc(struct inode *inode)
126 struct extent_position epos = { NULL, 0, {0, 0} };
129 uint64_t lbcount = 0;
130 int8_t etype = -1, netype;
133 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB ||
134 inode->i_size == UDF_I_LENEXTENTS(inode))
137 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
138 adsize = sizeof(short_ad);
139 else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
140 adsize = sizeof(long_ad);
144 epos.block = UDF_I_LOCATION(inode);
146 /* Find the last extent in the file */
147 while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1) {
151 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
152 epos.offset -= adsize;
154 extent_trunc(inode, &epos, eloc, etype, elen, 0);
156 UDF_I_LENALLOC(inode) =
157 epos.offset - udf_file_entry_alloc_offset(inode);
158 mark_inode_dirty(inode);
160 struct allocExtDesc *aed =
161 (struct allocExtDesc *)(epos.bh->b_data);
162 aed->lengthAllocDescs =
163 cpu_to_le32(epos.offset -
164 sizeof(struct allocExtDesc));
165 if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) ||
166 UDF_SB(inode->i_sb)->s_udfrev >= 0x0201)
167 udf_update_tag(epos.bh->b_data, epos.offset);
169 udf_update_tag(epos.bh->b_data,
170 sizeof(struct allocExtDesc));
171 mark_buffer_dirty_inode(epos.bh, inode);
174 /* This inode entry is in-memory only and thus we don't have to mark
176 UDF_I_LENEXTENTS(inode) = lbcount;
180 void udf_truncate_extents(struct inode *inode)
182 struct extent_position epos;
183 kernel_lb_addr eloc, neloc = {};
184 uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
186 struct super_block *sb = inode->i_sb;
187 struct udf_sb_info *sbi = UDF_SB(sb);
188 sector_t first_block = inode->i_size >> sb->s_blocksize_bits, offset;
192 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
193 adsize = sizeof(short_ad);
194 else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
195 adsize = sizeof(long_ad);
199 etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
200 byte_offset = (offset << sb->s_blocksize_bits) +
201 (inode->i_size & (sb->s_blocksize - 1));
203 epos.offset -= adsize;
204 extent_trunc(inode, &epos, eloc, etype, elen, byte_offset);
205 epos.offset += adsize;
207 lenalloc = epos.offset;
209 lenalloc = epos.offset - adsize;
212 lenalloc -= udf_file_entry_alloc_offset(inode);
214 lenalloc -= sizeof(struct allocExtDesc);
216 while ((etype = udf_current_aext(inode, &epos, &eloc, &elen, 0)) != -1) {
217 if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30)) {
218 udf_write_aext(inode, &epos, neloc, nelen, 0);
219 if (indirect_ext_len) {
220 /* We managed to free all extents in the
221 * indirect extent - free it too */
224 udf_free_blocks(sb, inode, epos.block,
225 0, indirect_ext_len);
228 UDF_I_LENALLOC(inode) = lenalloc;
229 mark_inode_dirty(inode);
231 struct allocExtDesc *aed =
232 (struct allocExtDesc *)(epos.bh->b_data);
233 aed->lengthAllocDescs =
234 cpu_to_le32(lenalloc);
235 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) ||
236 sbi->s_udfrev >= 0x0201)
237 udf_update_tag(epos.bh->b_data,
239 sizeof(struct allocExtDesc));
241 udf_update_tag(epos.bh->b_data,
242 sizeof(struct allocExtDesc));
243 mark_buffer_dirty_inode(epos.bh, inode);
247 epos.offset = sizeof(struct allocExtDesc);
249 epos.bh = udf_tread(sb, udf_get_lb_pblock(sb, eloc, 0));
251 indirect_ext_len = (elen + sb->s_blocksize -1) >>
252 sb->s_blocksize_bits;
254 indirect_ext_len = 1;
256 extent_trunc(inode, &epos, eloc, etype, elen, 0);
257 epos.offset += adsize;
261 if (indirect_ext_len) {
264 udf_free_blocks(sb, inode, epos.block, 0,
268 UDF_I_LENALLOC(inode) = lenalloc;
269 mark_inode_dirty(inode);
271 struct allocExtDesc *aed =
272 (struct allocExtDesc *)(epos.bh->b_data);
273 aed->lengthAllocDescs = cpu_to_le32(lenalloc);
274 if (!UDF_QUERY_FLAG(sb, UDF_FLAG_STRICT) ||
275 sbi->s_udfrev >= 0x0201)
276 udf_update_tag(epos.bh->b_data,
277 lenalloc + sizeof(struct allocExtDesc));
279 udf_update_tag(epos.bh->b_data,
280 sizeof(struct allocExtDesc));
281 mark_buffer_dirty_inode(epos.bh, inode);
284 } else if (inode->i_size) {
286 kernel_long_ad extent;
289 * OK, there is not extent covering inode->i_size and
290 * no extent above inode->i_size => truncate is
291 * extending the file by 'offset' blocks.
294 epos.offset == udf_file_entry_alloc_offset(inode)) ||
295 (epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
296 /* File has no extents at all or has empty last
297 * indirect extent! Create a fake extent... */
298 extent.extLocation.logicalBlockNum = 0;
299 extent.extLocation.partitionReferenceNum = 0;
300 extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
302 epos.offset -= adsize;
303 etype = udf_next_aext(inode, &epos,
305 &extent.extLength, 0);
306 extent.extLength |= etype << 30;
308 udf_extend_file(inode, &epos, &extent,
309 offset + ((inode->i_size & (sb->s_blocksize - 1)) != 0));
312 UDF_I_LENEXTENTS(inode) = inode->i_size;