1 /*
2 * alloc_tables.c --- Allocate tables for a newly initialized
3 * filesystem. Used by mke2fs when initializing a filesystem
4 *
5 * Copyright (C) 1996 Theodore Ts'o.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the GNU Library
9 * General Public License, version 2.
10 * %End-Header%
11 */
12
13 #include <stdio.h>
14 #include <string.h>
15 #if HAVE_UNISTD_H
16 #include <unistd.h>
17 #endif
18 #include <fcntl.h>
19 #include <time.h>
20 #if HAVE_SYS_STAT_H
21 #include <sys/stat.h>
22 #endif
23 #if HAVE_SYS_TYPES_H
24 #include <sys/types.h>
25 #endif
26
27 #include "ext2_fs.h"
28 #include "ext2fs.h"
29
30 /*
31 * This routine searches for free blocks that can allocate a full
32 * group of bitmaps or inode tables for a flexbg group. Returns the
33 * block number with a correct offset were the bitmaps and inode
34 * tables can be allocated continously and in order.
35 */
flexbg_offset(ext2_filsys fs,dgrp_t group,blk_t start_blk,ext2fs_block_bitmap bmap,int offset,int size,int elem_size)36 static blk_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk_t start_blk,
37 ext2fs_block_bitmap bmap, int offset, int size,
38 int elem_size)
39 {
40 int flexbg, flexbg_size;
41 blk_t last_blk, first_free = 0;
42 dgrp_t last_grp;
43
44 flexbg_size = 1 << fs->super->s_log_groups_per_flex;
45 flexbg = group / flexbg_size;
46
47 if (size > (int) (fs->super->s_blocks_per_group / 8))
48 size = (int) fs->super->s_blocks_per_group / 8;
49
50 if (offset)
51 offset -= 1;
52
53 /*
54 * Don't do a long search if the previous block
55 * search is still valid.
56 */
57 if (start_blk && group % flexbg_size) {
58 if (ext2fs_test_block_bitmap_range(bmap, start_blk + elem_size,
59 size))
60 return start_blk + elem_size;
61 }
62
63 start_blk = ext2fs_group_first_block(fs, flexbg_size * flexbg);
64 last_grp = group | (flexbg_size - 1);
65 if (last_grp > fs->group_desc_count)
66 last_grp = fs->group_desc_count;
67 last_blk = ext2fs_group_last_block(fs, last_grp);
68
69 /* Find the first available block */
70 if (ext2fs_get_free_blocks(fs, start_blk, last_blk, 1, bmap,
71 &first_free))
72 return first_free;
73
74 if (ext2fs_get_free_blocks(fs, first_free + offset, last_blk, size,
75 bmap, &first_free))
76 return first_free;
77
78 return first_free;
79 }
80
ext2fs_allocate_group_table(ext2_filsys fs,dgrp_t group,ext2fs_block_bitmap bmap)81 errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
82 ext2fs_block_bitmap bmap)
83 {
84 errcode_t retval;
85 blk_t group_blk, start_blk, last_blk, new_blk, blk;
86 dgrp_t last_grp = 0;
87 int j, rem_grps = 0, flexbg_size = 0;
88
89 group_blk = ext2fs_group_first_block(fs, group);
90 last_blk = ext2fs_group_last_block(fs, group);
91
92 if (!bmap)
93 bmap = fs->block_map;
94
95 if (EXT2_HAS_INCOMPAT_FEATURE(fs->super,
96 EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
97 fs->super->s_log_groups_per_flex) {
98 flexbg_size = 1 << fs->super->s_log_groups_per_flex;
99 last_grp = group | (flexbg_size - 1);
100 rem_grps = last_grp - group;
101 if (last_grp > fs->group_desc_count)
102 last_grp = fs->group_desc_count;
103 }
104
105 /*
106 * Allocate the block and inode bitmaps, if necessary
107 */
108 if (fs->stride) {
109 retval = ext2fs_get_free_blocks(fs, group_blk, last_blk,
110 1, bmap, &start_blk);
111 if (retval)
112 return retval;
113 start_blk += fs->inode_blocks_per_group;
114 start_blk += ((fs->stride * group) %
115 (last_blk - start_blk + 1));
116 if (start_blk >= last_blk)
117 start_blk = group_blk;
118 } else
119 start_blk = group_blk;
120
121 if (flexbg_size) {
122 blk_t prev_block = 0;
123 if (group && fs->group_desc[group-1].bg_block_bitmap)
124 prev_block = fs->group_desc[group-1].bg_block_bitmap;
125 start_blk = flexbg_offset(fs, group, prev_block, bmap,
126 0, rem_grps, 1);
127 last_blk = ext2fs_group_last_block(fs, last_grp);
128 }
129
130 if (!fs->group_desc[group].bg_block_bitmap) {
131 retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
132 1, bmap, &new_blk);
133 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
134 retval = ext2fs_get_free_blocks(fs, group_blk,
135 last_blk, 1, bmap, &new_blk);
136 if (retval)
137 return retval;
138 ext2fs_mark_block_bitmap(bmap, new_blk);
139 fs->group_desc[group].bg_block_bitmap = new_blk;
140 if (flexbg_size) {
141 dgrp_t gr = ext2fs_group_of_blk(fs, new_blk);
142 fs->group_desc[gr].bg_free_blocks_count--;
143 fs->super->s_free_blocks_count--;
144 fs->group_desc[gr].bg_flags &= ~EXT2_BG_BLOCK_UNINIT;
145 ext2fs_group_desc_csum_set(fs, gr);
146 }
147 }
148
149 if (flexbg_size) {
150 blk_t prev_block = 0;
151 if (group && fs->group_desc[group-1].bg_inode_bitmap)
152 prev_block = fs->group_desc[group-1].bg_inode_bitmap;
153 start_blk = flexbg_offset(fs, group, prev_block, bmap,
154 flexbg_size, rem_grps, 1);
155 last_blk = ext2fs_group_last_block(fs, last_grp);
156 }
157
158 if (!fs->group_desc[group].bg_inode_bitmap) {
159 retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
160 1, bmap, &new_blk);
161 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
162 retval = ext2fs_get_free_blocks(fs, group_blk,
163 last_blk, 1, bmap, &new_blk);
164 if (retval)
165 return retval;
166 ext2fs_mark_block_bitmap(bmap, new_blk);
167 fs->group_desc[group].bg_inode_bitmap = new_blk;
168 if (flexbg_size) {
169 dgrp_t gr = ext2fs_group_of_blk(fs, new_blk);
170 fs->group_desc[gr].bg_free_blocks_count--;
171 fs->super->s_free_blocks_count--;
172 fs->group_desc[gr].bg_flags &= ~EXT2_BG_BLOCK_UNINIT;
173 ext2fs_group_desc_csum_set(fs, gr);
174 }
175 }
176
177 /*
178 * Allocate the inode table
179 */
180 if (flexbg_size) {
181 blk_t prev_block = 0;
182 if (group && fs->group_desc[group-1].bg_inode_table)
183 prev_block = fs->group_desc[group-1].bg_inode_table;
184 if (last_grp == fs->group_desc_count)
185 rem_grps = last_grp - group;
186 group_blk = flexbg_offset(fs, group, prev_block, bmap,
187 flexbg_size * 2,
188 fs->inode_blocks_per_group *
189 rem_grps,
190 fs->inode_blocks_per_group);
191 last_blk = ext2fs_group_last_block(fs, last_grp);
192 }
193
194 if (!fs->group_desc[group].bg_inode_table) {
195 retval = ext2fs_get_free_blocks(fs, group_blk, last_blk,
196 fs->inode_blocks_per_group,
197 bmap, &new_blk);
198 if (retval)
199 return retval;
200 for (j=0, blk = new_blk;
201 j < fs->inode_blocks_per_group;
202 j++, blk++) {
203 ext2fs_mark_block_bitmap(bmap, blk);
204 if (flexbg_size) {
205 dgrp_t gr = ext2fs_group_of_blk(fs, blk);
206 fs->group_desc[gr].bg_free_blocks_count--;
207 fs->super->s_free_blocks_count--;
208 fs->group_desc[gr].bg_flags &= ~EXT2_BG_BLOCK_UNINIT;
209 ext2fs_group_desc_csum_set(fs, gr);
210 }
211 }
212 fs->group_desc[group].bg_inode_table = new_blk;
213 }
214 ext2fs_group_desc_csum_set(fs, group);
215 return 0;
216 }
217
ext2fs_allocate_tables(ext2_filsys fs)218 errcode_t ext2fs_allocate_tables(ext2_filsys fs)
219 {
220 errcode_t retval;
221 dgrp_t i;
222
223 for (i = 0; i < fs->group_desc_count; i++) {
224 retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
225 if (retval)
226 return retval;
227 }
228 return 0;
229 }
230
231