blob: cbb63e15a5d6310e8598e61bf6042c9ab522e709
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * alloc.c --- allocate new inodes, blocks for ext2fs |
4 | * |
5 | * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. |
6 | * |
7 | * %Begin-Header% |
8 | * This file may be redistributed under the terms of the GNU Public |
9 | * License. |
10 | * %End-Header% |
11 | * |
12 | */ |
13 | |
14 | #include <stdio.h> |
15 | #if HAVE_UNISTD_H |
16 | #include <unistd.h> |
17 | #endif |
18 | #include <time.h> |
19 | #include <string.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 | * Right now, just search forward from the parent directory's block |
32 | * group to find the next free inode. |
33 | * |
34 | * Should have a special policy for directories. |
35 | */ |
36 | errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir, |
37 | int mode EXT2FS_ATTR((unused)), |
38 | ext2fs_inode_bitmap map, ext2_ino_t *ret) |
39 | { |
40 | ext2_ino_t dir_group = 0; |
41 | ext2_ino_t i; |
42 | ext2_ino_t start_inode; |
43 | |
44 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
45 | |
46 | if (!map) |
47 | map = fs->inode_map; |
48 | if (!map) |
49 | return EXT2_ET_NO_INODE_BITMAP; |
50 | |
51 | if (dir > 0) |
52 | dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super); |
53 | |
54 | start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1; |
55 | if (start_inode < EXT2_FIRST_INODE(fs->super)) |
56 | start_inode = EXT2_FIRST_INODE(fs->super); |
57 | i = start_inode; |
58 | |
59 | do { |
60 | if (!ext2fs_fast_test_inode_bitmap(map, i)) |
61 | break; |
62 | i++; |
63 | if (i > fs->super->s_inodes_count) |
64 | i = EXT2_FIRST_INODE(fs->super); |
65 | } while (i != start_inode); |
66 | |
67 | if (ext2fs_test_inode_bitmap(map, i)) |
68 | return EXT2_ET_INODE_ALLOC_FAIL; |
69 | *ret = i; |
70 | return 0; |
71 | } |
72 | |
73 | /* |
74 | * Stupid algorithm --- we now just search forward starting from the |
75 | * goal. Should put in a smarter one someday.... |
76 | */ |
77 | errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal, |
78 | ext2fs_block_bitmap map, blk_t *ret) |
79 | { |
80 | blk_t i; |
81 | |
82 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
83 | |
84 | if (!map) |
85 | map = fs->block_map; |
86 | if (!map) |
87 | return EXT2_ET_NO_BLOCK_BITMAP; |
88 | if (!goal || (goal >= fs->super->s_blocks_count)) |
89 | goal = fs->super->s_first_data_block; |
90 | i = goal; |
91 | do { |
92 | if (!ext2fs_fast_test_block_bitmap(map, i)) { |
93 | *ret = i; |
94 | return 0; |
95 | } |
96 | i++; |
97 | if (i >= fs->super->s_blocks_count) |
98 | i = fs->super->s_first_data_block; |
99 | } while (i != goal); |
100 | return EXT2_ET_BLOCK_ALLOC_FAIL; |
101 | } |
102 | |
103 | /* |
104 | * This function zeros out the allocated block, and updates all of the |
105 | * appropriate filesystem records. |
106 | */ |
107 | errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal, |
108 | char *block_buf, blk_t *ret) |
109 | { |
110 | errcode_t retval; |
111 | blk_t block; |
112 | char *buf = NULL; |
113 | |
114 | if (!block_buf) { |
115 | retval = ext2fs_get_mem(fs->blocksize, &buf); |
116 | if (retval) |
117 | return retval; |
118 | block_buf = buf; |
119 | } |
120 | memset(block_buf, 0, fs->blocksize); |
121 | |
122 | if (!fs->block_map) { |
123 | retval = ext2fs_read_block_bitmap(fs); |
124 | if (retval) |
125 | goto fail; |
126 | } |
127 | |
128 | retval = ext2fs_new_block(fs, goal, 0, &block); |
129 | if (retval) |
130 | goto fail; |
131 | |
132 | retval = io_channel_write_blk(fs->io, block, 1, block_buf); |
133 | if (retval) |
134 | goto fail; |
135 | |
136 | ext2fs_block_alloc_stats(fs, block, +1); |
137 | *ret = block; |
138 | return 0; |
139 | |
140 | fail: |
141 | if (buf) |
142 | ext2fs_free_mem(&buf); |
143 | return retval; |
144 | } |
145 | |
146 | errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish, |
147 | int num, ext2fs_block_bitmap map, blk_t *ret) |
148 | { |
149 | blk_t b = start; |
150 | |
151 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
152 | |
153 | if (!map) |
154 | map = fs->block_map; |
155 | if (!map) |
156 | return EXT2_ET_NO_BLOCK_BITMAP; |
157 | if (!b) |
158 | b = fs->super->s_first_data_block; |
159 | if (!finish) |
160 | finish = start; |
161 | if (!num) |
162 | num = 1; |
163 | do { |
164 | if (b+num-1 > fs->super->s_blocks_count) |
165 | b = fs->super->s_first_data_block; |
166 | if (ext2fs_fast_test_block_bitmap_range(map, b, num)) { |
167 | *ret = b; |
168 | return 0; |
169 | } |
170 | b++; |
171 | } while (b != finish); |
172 | return EXT2_ET_BLOCK_ALLOC_FAIL; |
173 | } |
174 |