1 /*
2 * alloc.c --- allocate new inodes, blocks for ext2fs
3 *
4 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Library
8 * General Public License, version 2.
9 * %End-Header%
10 */
11
12 #include <stdio.h>
13 #if HAVE_UNISTD_H
14 #include <unistd.h>
15 #endif
16 #include <time.h>
17 #include <string.h>
18 #if HAVE_SYS_STAT_H
19 #include <sys/stat.h>
20 #endif
21 #if HAVE_SYS_TYPES_H
22 #include <sys/types.h>
23 #endif
24
25 #include "ext2_fs.h"
26 #include "ext2fs.h"
27
28 /*
29 * Check for uninit block bitmaps and deal with them appropriately
30 */
check_block_uninit(ext2_filsys fs,ext2fs_block_bitmap map,dgrp_t group)31 static void check_block_uninit(ext2_filsys fs, ext2fs_block_bitmap map,
32 dgrp_t group)
33 {
34 blk_t i;
35 blk64_t blk, super_blk, old_desc_blk, new_desc_blk;
36 int old_desc_blocks;
37
38 if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
39 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
40 !(ext2fs_bg_flags_test(fs, group, EXT2_BG_BLOCK_UNINIT)))
41 return;
42
43 blk = ext2fs_group_first_block2(fs, group);
44
45 ext2fs_super_and_bgd_loc2(fs, group, &super_blk,
46 &old_desc_blk, &new_desc_blk, 0);
47
48 if (fs->super->s_feature_incompat &
49 EXT2_FEATURE_INCOMPAT_META_BG)
50 old_desc_blocks = fs->super->s_first_meta_bg;
51 else
52 old_desc_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
53
54 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++)
55 ext2fs_fast_unmark_block_bitmap2(map, blk);
56
57 blk = ext2fs_group_first_block2(fs, group);
58 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) {
59 if ((blk == super_blk) ||
60 (old_desc_blk && old_desc_blocks &&
61 (blk >= old_desc_blk) &&
62 (blk < old_desc_blk + old_desc_blocks)) ||
63 (new_desc_blk && (blk == new_desc_blk)) ||
64 (blk == ext2fs_block_bitmap_loc(fs, group)) ||
65 (blk == ext2fs_inode_bitmap_loc(fs, group)) ||
66 (blk >= ext2fs_inode_table_loc(fs, group) &&
67 (blk < ext2fs_inode_table_loc(fs, group)
68 + fs->inode_blocks_per_group)))
69 ext2fs_fast_mark_block_bitmap2(map, blk);
70 }
71 ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
72 ext2fs_group_desc_csum_set(fs, group);
73 ext2fs_mark_super_dirty(fs);
74 ext2fs_mark_bb_dirty(fs);
75 }
76
77 /*
78 * Check for uninit inode bitmaps and deal with them appropriately
79 */
check_inode_uninit(ext2_filsys fs,ext2fs_inode_bitmap map,dgrp_t group)80 static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map,
81 dgrp_t group)
82 {
83 ext2_ino_t i, ino;
84
85 if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
86 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
87 !(ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT)))
88 return;
89
90 ino = (group * fs->super->s_inodes_per_group) + 1;
91 for (i=0; i < fs->super->s_inodes_per_group; i++, ino++)
92 ext2fs_fast_unmark_inode_bitmap2(map, ino);
93
94 ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
95 ext2fs_group_desc_csum_set(fs, group);
96 ext2fs_mark_ib_dirty(fs);
97 ext2fs_mark_super_dirty(fs);
98 check_block_uninit(fs, fs->block_map, group);
99 }
100
101 /*
102 * Right now, just search forward from the parent directory's block
103 * group to find the next free inode.
104 *
105 * Should have a special policy for directories.
106 */
ext2fs_new_inode(ext2_filsys fs,ext2_ino_t dir,int mode EXT2FS_ATTR ((unused)),ext2fs_inode_bitmap map,ext2_ino_t * ret)107 errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
108 int mode EXT2FS_ATTR((unused)),
109 ext2fs_inode_bitmap map, ext2_ino_t *ret)
110 {
111 ext2_ino_t start_inode = 0;
112 ext2_ino_t i, ino_in_group, upto, first_zero;
113 errcode_t retval;
114 dgrp_t group;
115
116 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
117
118 if (!map)
119 map = fs->inode_map;
120 if (!map)
121 return EXT2_ET_NO_INODE_BITMAP;
122
123 if (dir > 0) {
124 group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
125 start_inode = (group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
126 }
127 if (start_inode < EXT2_FIRST_INODE(fs->super))
128 start_inode = EXT2_FIRST_INODE(fs->super);
129 if (start_inode > fs->super->s_inodes_count)
130 return EXT2_ET_INODE_ALLOC_FAIL;
131 i = start_inode;
132 do {
133 ino_in_group = (i - 1) % EXT2_INODES_PER_GROUP(fs->super);
134 group = (i - 1) / EXT2_INODES_PER_GROUP(fs->super);
135
136 check_inode_uninit(fs, map, group);
137 upto = i + (EXT2_INODES_PER_GROUP(fs->super) - ino_in_group);
138 if (i < start_inode && upto >= start_inode)
139 upto = start_inode - 1;
140 if (upto > fs->super->s_inodes_count)
141 upto = fs->super->s_inodes_count;
142
143 retval = ext2fs_find_first_zero_inode_bitmap2(map, i, upto,
144 &first_zero);
145 if (retval == 0) {
146 i = first_zero;
147 break;
148 }
149 if (retval != ENOENT)
150 return EXT2_ET_INODE_ALLOC_FAIL;
151 i = upto + 1;
152 if (i > fs->super->s_inodes_count)
153 i = EXT2_FIRST_INODE(fs->super);
154 } while (i != start_inode);
155
156 if (ext2fs_test_inode_bitmap2(map, i))
157 return EXT2_ET_INODE_ALLOC_FAIL;
158 *ret = i;
159 return 0;
160 }
161
162 /*
163 * Stupid algorithm --- we now just search forward starting from the
164 * goal. Should put in a smarter one someday....
165 */
ext2fs_new_block2(ext2_filsys fs,blk64_t goal,ext2fs_block_bitmap map,blk64_t * ret)166 errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal,
167 ext2fs_block_bitmap map, blk64_t *ret)
168 {
169 blk64_t i;
170 int c_ratio;
171
172 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
173
174 if (!map)
175 map = fs->block_map;
176 if (!map)
177 return EXT2_ET_NO_BLOCK_BITMAP;
178 if (!goal || (goal >= ext2fs_blocks_count(fs->super)))
179 goal = fs->super->s_first_data_block;
180 i = goal;
181 c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
182 if (c_ratio > 1)
183 goal &= ~EXT2FS_CLUSTER_MASK(fs);
184 check_block_uninit(fs, map,
185 (i - fs->super->s_first_data_block) /
186 EXT2_BLOCKS_PER_GROUP(fs->super));
187 do {
188 if (((i - fs->super->s_first_data_block) %
189 EXT2_BLOCKS_PER_GROUP(fs->super)) == 0)
190 check_block_uninit(fs, map,
191 (i - fs->super->s_first_data_block) /
192 EXT2_BLOCKS_PER_GROUP(fs->super));
193
194 if (!ext2fs_fast_test_block_bitmap2(map, i)) {
195 *ret = i;
196 return 0;
197 }
198 i = (i + c_ratio) & ~(c_ratio - 1);
199 if (i >= ext2fs_blocks_count(fs->super))
200 i = fs->super->s_first_data_block;
201 } while (i != goal);
202 return EXT2_ET_BLOCK_ALLOC_FAIL;
203 }
204
ext2fs_new_block(ext2_filsys fs,blk_t goal,ext2fs_block_bitmap map,blk_t * ret)205 errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
206 ext2fs_block_bitmap map, blk_t *ret)
207 {
208 errcode_t retval;
209 blk64_t val;
210 retval = ext2fs_new_block2(fs, goal, map, &val);
211 if (!retval)
212 *ret = (blk_t) val;
213 return retval;
214 }
215
216 /*
217 * This function zeros out the allocated block, and updates all of the
218 * appropriate filesystem records.
219 */
ext2fs_alloc_block2(ext2_filsys fs,blk64_t goal,char * block_buf,blk64_t * ret)220 errcode_t ext2fs_alloc_block2(ext2_filsys fs, blk64_t goal,
221 char *block_buf, blk64_t *ret)
222 {
223 errcode_t retval;
224 blk64_t block;
225 char *buf = 0;
226
227 if (!block_buf) {
228 retval = ext2fs_get_mem(fs->blocksize, &buf);
229 if (retval)
230 return retval;
231 block_buf = buf;
232 }
233 memset(block_buf, 0, fs->blocksize);
234
235 if (fs->get_alloc_block) {
236 retval = (fs->get_alloc_block)(fs, goal, &block);
237 if (retval)
238 goto fail;
239 } else {
240 if (!fs->block_map) {
241 retval = ext2fs_read_block_bitmap(fs);
242 if (retval)
243 goto fail;
244 }
245
246 retval = ext2fs_new_block2(fs, goal, 0, &block);
247 if (retval)
248 goto fail;
249 }
250
251 retval = io_channel_write_blk64(fs->io, block, 1, block_buf);
252 if (retval)
253 goto fail;
254
255 ext2fs_block_alloc_stats2(fs, block, +1);
256 *ret = block;
257
258 fail:
259 if (buf)
260 ext2fs_free_mem(&buf);
261 return retval;
262 }
263
ext2fs_alloc_block(ext2_filsys fs,blk_t goal,char * block_buf,blk_t * ret)264 errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
265 char *block_buf, blk_t *ret)
266 {
267 errcode_t retval;
268 blk64_t val;
269 retval = ext2fs_alloc_block2(fs, goal, block_buf, &val);
270 if (!retval)
271 *ret = (blk_t) val;
272 return retval;
273 }
274
ext2fs_get_free_blocks2(ext2_filsys fs,blk64_t start,blk64_t finish,int num,ext2fs_block_bitmap map,blk64_t * ret)275 errcode_t ext2fs_get_free_blocks2(ext2_filsys fs, blk64_t start, blk64_t finish,
276 int num, ext2fs_block_bitmap map, blk64_t *ret)
277 {
278 blk64_t b = start;
279 int c_ratio;
280
281 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
282
283 if (!map)
284 map = fs->block_map;
285 if (!map)
286 return EXT2_ET_NO_BLOCK_BITMAP;
287 if (!b)
288 b = fs->super->s_first_data_block;
289 if (!finish)
290 finish = start;
291 if (!num)
292 num = 1;
293 c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
294 b &= ~(c_ratio - 1);
295 finish &= ~(c_ratio -1);
296 do {
297 if (b+num-1 > ext2fs_blocks_count(fs->super))
298 b = fs->super->s_first_data_block;
299 if (ext2fs_fast_test_block_bitmap_range2(map, b, num)) {
300 *ret = b;
301 return 0;
302 }
303 b += c_ratio;
304 } while (b != finish);
305 return EXT2_ET_BLOCK_ALLOC_FAIL;
306 }
307
ext2fs_get_free_blocks(ext2_filsys fs,blk_t start,blk_t finish,int num,ext2fs_block_bitmap map,blk_t * ret)308 errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
309 int num, ext2fs_block_bitmap map, blk_t *ret)
310 {
311 errcode_t retval;
312 blk64_t val;
313 retval = ext2fs_get_free_blocks2(fs, start, finish, num, map, &val);
314 if(!retval)
315 *ret = (blk_t) val;
316 return retval;
317 }
318
ext2fs_set_alloc_block_callback(ext2_filsys fs,errcode_t (* func)(ext2_filsys fs,blk64_t goal,blk64_t * ret),errcode_t (** old)(ext2_filsys fs,blk64_t goal,blk64_t * ret))319 void ext2fs_set_alloc_block_callback(ext2_filsys fs,
320 errcode_t (*func)(ext2_filsys fs,
321 blk64_t goal,
322 blk64_t *ret),
323 errcode_t (**old)(ext2_filsys fs,
324 blk64_t goal,
325 blk64_t *ret))
326 {
327 if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
328 return;
329
330 if (old)
331 *old = fs->get_alloc_block;
332
333 fs->get_alloc_block = func;
334 }
335