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 Public
8 * License.
9 * %End-Header%
10 *
11 */
12
13 #include <stdio.h>
14 #if HAVE_UNISTD_H
15 #include <unistd.h>
16 #endif
17 #include <time.h>
18 #include <string.h>
19 #if HAVE_SYS_STAT_H
20 #include <sys/stat.h>
21 #endif
22 #if HAVE_SYS_TYPES_H
23 #include <sys/types.h>
24 #endif
25
26 #include "ext2_fs.h"
27 #include "ext2fs.h"
28
29 /*
30 * Right now, just search forward from the parent directory's block
31 * group to find the next free inode.
32 *
33 * Should have a special policy for directories.
34 */
ext2fs_new_inode(ext2_filsys fs,ext2_ino_t dir,int mode EXT2FS_ATTR ((unused)),ext2fs_inode_bitmap map,ext2_ino_t * ret)35 errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
36 int mode EXT2FS_ATTR((unused)),
37 ext2fs_inode_bitmap map, ext2_ino_t *ret)
38 {
39 ext2_ino_t dir_group = 0;
40 ext2_ino_t i;
41 ext2_ino_t start_inode;
42
43 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
44
45 if (!map)
46 map = fs->inode_map;
47 if (!map)
48 return EXT2_ET_NO_INODE_BITMAP;
49
50 if (dir > 0)
51 dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
52
53 start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
54 if (start_inode < EXT2_FIRST_INODE(fs->super))
55 start_inode = EXT2_FIRST_INODE(fs->super);
56 i = start_inode;
57
58 do {
59 if (!ext2fs_fast_test_inode_bitmap(map, i))
60 break;
61 i++;
62 if (i > fs->super->s_inodes_count)
63 i = EXT2_FIRST_INODE(fs->super);
64 } while (i != start_inode);
65
66 if (ext2fs_test_inode_bitmap(map, i))
67 return EXT2_ET_INODE_ALLOC_FAIL;
68 *ret = i;
69 return 0;
70 }
71
72 /*
73 * Stupid algorithm --- we now just search forward starting from the
74 * goal. Should put in a smarter one someday....
75 */
ext2fs_new_block(ext2_filsys fs,blk_t goal,ext2fs_block_bitmap map,blk_t * ret)76 errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
77 ext2fs_block_bitmap map, blk_t *ret)
78 {
79 blk_t i;
80
81 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
82
83 if (!map)
84 map = fs->block_map;
85 if (!map)
86 return EXT2_ET_NO_BLOCK_BITMAP;
87 if (!goal || (goal >= fs->super->s_blocks_count))
88 goal = fs->super->s_first_data_block;
89 i = goal;
90 do {
91 if (!ext2fs_fast_test_block_bitmap(map, i)) {
92 *ret = i;
93 return 0;
94 }
95 i++;
96 if (i >= fs->super->s_blocks_count)
97 i = fs->super->s_first_data_block;
98 } while (i != goal);
99 return EXT2_ET_BLOCK_ALLOC_FAIL;
100 }
101
102 /*
103 * This function zeros out the allocated block, and updates all of the
104 * appropriate filesystem records.
105 */
ext2fs_alloc_block(ext2_filsys fs,blk_t goal,char * block_buf,blk_t * ret)106 errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
107 char *block_buf, blk_t *ret)
108 {
109 errcode_t retval;
110 blk_t block;
111 char *buf = 0;
112
113 if (!block_buf) {
114 retval = ext2fs_get_mem(fs->blocksize, &buf);
115 if (retval)
116 return retval;
117 block_buf = buf;
118 }
119 memset(block_buf, 0, fs->blocksize);
120
121 if (!fs->block_map) {
122 retval = ext2fs_read_block_bitmap(fs);
123 if (retval)
124 goto fail;
125 }
126
127 retval = ext2fs_new_block(fs, goal, 0, &block);
128 if (retval)
129 goto fail;
130
131 retval = io_channel_write_blk(fs->io, block, 1, block_buf);
132 if (retval)
133 goto fail;
134
135 ext2fs_block_alloc_stats(fs, block, +1);
136 *ret = block;
137
138 fail:
139 if (buf)
140 ext2fs_free_mem(&buf);
141 return retval;
142 }
143
ext2fs_get_free_blocks(ext2_filsys fs,blk_t start,blk_t finish,int num,ext2fs_block_bitmap map,blk_t * ret)144 errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
145 int num, ext2fs_block_bitmap map, blk_t *ret)
146 {
147 blk_t b = start;
148
149 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
150
151 if (!map)
152 map = fs->block_map;
153 if (!map)
154 return EXT2_ET_NO_BLOCK_BITMAP;
155 if (!b)
156 b = fs->super->s_first_data_block;
157 if (!finish)
158 finish = start;
159 if (!num)
160 num = 1;
161 do {
162 if (b+num-1 > fs->super->s_blocks_count)
163 b = fs->super->s_first_data_block;
164 if (ext2fs_fast_test_block_bitmap_range(map, b, num)) {
165 *ret = b;
166 return 0;
167 }
168 b++;
169 } while (b != finish);
170 return EXT2_ET_BLOCK_ALLOC_FAIL;
171 }
172
173