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, uint32_t nelen)
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;
40 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
42 udf_free_blocks(inode->i_sb, inode, eloc, 0, last_block);
43 etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
47 nelen = (etype << 30) | nelen;
52 udf_write_aext(inode, epos, neloc, nelen, 0);
53 if (last_block - first_block > 0)
55 if (etype == (EXT_RECORDED_ALLOCATED >> 30))
56 mark_inode_dirty(inode);
58 if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
59 udf_free_blocks(inode->i_sb, inode, eloc, first_block, last_block - first_block);
64 void udf_discard_prealloc(struct inode * inode)
66 struct extent_position epos = { NULL, 0, {0, 0}};
70 int8_t etype = -1, netype;
73 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB ||
74 inode->i_size == UDF_I_LENEXTENTS(inode))
77 if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
78 adsize = sizeof(short_ad);
79 else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
80 adsize = sizeof(long_ad);
84 epos.block = UDF_I_LOCATION(inode);
86 /* Find the last extent in the file */
87 while ((netype = udf_next_aext(inode, &epos, &eloc, &elen, 1)) != -1)
91 if (lbcount > inode->i_size && lbcount - elen < inode->i_size)
93 WARN_ON(lbcount - inode->i_size >= inode->i_sb->s_blocksize);
94 nelen = elen - (lbcount - inode->i_size);
95 epos.offset -= adsize;
96 extent_trunc(inode, &epos, eloc, etype, elen, nelen);
97 epos.offset += adsize;
98 lbcount = inode->i_size;
101 if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
102 epos.offset -= adsize;
104 extent_trunc(inode, &epos, eloc, etype, elen, 0);
107 UDF_I_LENALLOC(inode) = epos.offset - udf_file_entry_alloc_offset(inode);
108 mark_inode_dirty(inode);
112 struct allocExtDesc *aed = (struct allocExtDesc *)(epos.bh->b_data);
113 aed->lengthAllocDescs = cpu_to_le32(epos.offset - sizeof(struct allocExtDesc));
114 if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
115 udf_update_tag(epos.bh->b_data, epos.offset);
117 udf_update_tag(epos.bh->b_data, sizeof(struct allocExtDesc));
118 mark_buffer_dirty_inode(epos.bh, inode);
121 UDF_I_LENEXTENTS(inode) = lbcount;
123 WARN_ON(lbcount != inode->i_size);
127 void udf_truncate_extents(struct inode * inode)
129 struct extent_position epos;
130 kernel_lb_addr eloc, neloc = { 0, 0 };
131 uint32_t elen, nelen = 0, indirect_ext_len = 0, lenalloc;
133 sector_t first_block = inode->i_size >> inode->i_sb->s_blocksize_bits, offset;
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 etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
145 byte_offset = (offset << inode->i_sb->s_blocksize_bits) + (inode->i_size & (inode->i_sb->s_blocksize-1));
148 epos.offset -= adsize;
149 extent_trunc(inode, &epos, eloc, etype, elen, byte_offset);
150 epos.offset += adsize;
152 lenalloc = epos.offset;
154 lenalloc = epos.offset - adsize;
157 lenalloc -= udf_file_entry_alloc_offset(inode);
159 lenalloc -= sizeof(struct allocExtDesc);
161 while ((etype = udf_current_aext(inode, &epos, &eloc, &elen, 0)) != -1)
163 if (etype == (EXT_NEXT_EXTENT_ALLOCDECS >> 30))
165 udf_write_aext(inode, &epos, neloc, nelen, 0);
166 if (indirect_ext_len)
168 /* We managed to free all extents in the
169 * indirect extent - free it too */
172 udf_free_blocks(inode->i_sb, inode, epos.block, 0, indirect_ext_len);
178 UDF_I_LENALLOC(inode) = lenalloc;
179 mark_inode_dirty(inode);
183 struct allocExtDesc *aed = (struct allocExtDesc *)(epos.bh->b_data);
184 aed->lengthAllocDescs = cpu_to_le32(lenalloc);
185 if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
186 udf_update_tag(epos.bh->b_data, lenalloc +
187 sizeof(struct allocExtDesc));
189 udf_update_tag(epos.bh->b_data, sizeof(struct allocExtDesc));
190 mark_buffer_dirty_inode(epos.bh, inode);
194 epos.offset = sizeof(struct allocExtDesc);
196 epos.bh = udf_tread(inode->i_sb, udf_get_lb_pblock(inode->i_sb, eloc, 0));
198 indirect_ext_len = (elen +
199 inode->i_sb->s_blocksize - 1) >>
200 inode->i_sb->s_blocksize_bits;
202 indirect_ext_len = 1;
206 extent_trunc(inode, &epos, eloc, etype, elen, 0);
207 epos.offset += adsize;
211 if (indirect_ext_len)
215 udf_free_blocks(inode->i_sb, inode, epos.block, 0, indirect_ext_len);
221 UDF_I_LENALLOC(inode) = lenalloc;
222 mark_inode_dirty(inode);
226 struct allocExtDesc *aed = (struct allocExtDesc *)(epos.bh->b_data);
227 aed->lengthAllocDescs = cpu_to_le32(lenalloc);
228 if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
229 udf_update_tag(epos.bh->b_data, lenalloc +
230 sizeof(struct allocExtDesc));
232 udf_update_tag(epos.bh->b_data, sizeof(struct allocExtDesc));
233 mark_buffer_dirty_inode(epos.bh, inode);
237 else if (inode->i_size)
242 * OK, there is not extent covering inode->i_size and
243 * no extent above inode->i_size => truncate is
244 * extending the file by 'offset'.
246 if ((!epos.bh && epos.offset == udf_file_entry_alloc_offset(inode)) ||
247 (epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
248 /* File has no extents at all! */
249 memset(&eloc, 0x00, sizeof(kernel_lb_addr));
250 elen = EXT_NOT_RECORDED_NOT_ALLOCATED | byte_offset;
251 udf_add_aext(inode, &epos, eloc, elen, 1);
254 epos.offset -= adsize;
255 etype = udf_next_aext(inode, &epos, &eloc, &elen, 1);
257 if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
259 epos.offset -= adsize;
260 elen = EXT_NOT_RECORDED_NOT_ALLOCATED | (elen + byte_offset);
261 udf_write_aext(inode, &epos, eloc, elen, 0);
263 else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
265 kernel_lb_addr neloc = { 0, 0 };
266 epos.offset -= adsize;
267 nelen = EXT_NOT_RECORDED_NOT_ALLOCATED |
268 ((elen + byte_offset + inode->i_sb->s_blocksize - 1) &
269 ~(inode->i_sb->s_blocksize - 1));
270 udf_write_aext(inode, &epos, neloc, nelen, 1);
271 udf_add_aext(inode, &epos, eloc, (etype << 30) | elen, 1);
275 if (elen & (inode->i_sb->s_blocksize - 1))
277 epos.offset -= 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, &epos, eloc, elen, 1);
283 memset(&eloc, 0x00, sizeof(kernel_lb_addr));
284 elen = EXT_NOT_RECORDED_NOT_ALLOCATED | byte_offset;
285 udf_add_aext(inode, &epos, eloc, elen, 1);
290 UDF_I_LENEXTENTS(inode) = inode->i_size;