blob: 637ed27af9e854d3da028aa3ca81736c6ebaaccb
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * bitmaps.c --- routines to read, write, and manipulate the inode and |
4 | * block bitmaps. |
5 | * |
6 | * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o. |
7 | * |
8 | * %Begin-Header% |
9 | * This file may be redistributed under the terms of the GNU Public |
10 | * License. |
11 | * %End-Header% |
12 | */ |
13 | |
14 | #include <stdio.h> |
15 | #include <string.h> |
16 | #if HAVE_UNISTD_H |
17 | #include <unistd.h> |
18 | #endif |
19 | #include <fcntl.h> |
20 | #include <time.h> |
21 | #if HAVE_SYS_STAT_H |
22 | #include <sys/stat.h> |
23 | #endif |
24 | #if HAVE_SYS_TYPES_H |
25 | #include <sys/types.h> |
26 | #endif |
27 | |
28 | #include "ext2_fs.h" |
29 | #include "ext2fs.h" |
30 | |
31 | static errcode_t make_bitmap(__u32 start, __u32 end, __u32 real_end, |
32 | const char *descr, char *init_map, |
33 | ext2fs_generic_bitmap *ret) |
34 | { |
35 | ext2fs_generic_bitmap bitmap; |
36 | errcode_t retval; |
37 | size_t size; |
38 | |
39 | retval = ext2fs_get_mem(sizeof(struct ext2fs_struct_generic_bitmap), |
40 | &bitmap); |
41 | if (retval) |
42 | return retval; |
43 | |
44 | bitmap->magic = EXT2_ET_MAGIC_GENERIC_BITMAP; |
45 | bitmap->fs = NULL; |
46 | bitmap->start = start; |
47 | bitmap->end = end; |
48 | bitmap->real_end = real_end; |
49 | bitmap->base_error_code = EXT2_ET_BAD_GENERIC_MARK; |
50 | if (descr) { |
51 | retval = ext2fs_get_mem(strlen(descr)+1, &bitmap->description); |
52 | if (retval) { |
53 | ext2fs_free_mem(&bitmap); |
54 | return retval; |
55 | } |
56 | strcpy(bitmap->description, descr); |
57 | } else |
58 | bitmap->description = 0; |
59 | |
60 | size = (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1); |
61 | retval = ext2fs_get_mem(size, &bitmap->bitmap); |
62 | if (retval) { |
63 | ext2fs_free_mem(&bitmap->description); |
64 | ext2fs_free_mem(&bitmap); |
65 | return retval; |
66 | } |
67 | |
68 | if (init_map) |
69 | memcpy(bitmap->bitmap, init_map, size); |
70 | else |
71 | memset(bitmap->bitmap, 0, size); |
72 | *ret = bitmap; |
73 | return 0; |
74 | } |
75 | |
76 | errcode_t ext2fs_allocate_generic_bitmap(__u32 start, |
77 | __u32 end, |
78 | __u32 real_end, |
79 | const char *descr, |
80 | ext2fs_generic_bitmap *ret) |
81 | { |
82 | return make_bitmap(start, end, real_end, descr, 0, ret); |
83 | } |
84 | |
85 | errcode_t ext2fs_copy_bitmap(ext2fs_generic_bitmap src, |
86 | ext2fs_generic_bitmap *dest) |
87 | { |
88 | errcode_t retval; |
89 | ext2fs_generic_bitmap new_map; |
90 | |
91 | retval = make_bitmap(src->start, src->end, src->real_end, |
92 | src->description, src->bitmap, &new_map); |
93 | if (retval) |
94 | return retval; |
95 | new_map->magic = src->magic; |
96 | new_map->fs = src->fs; |
97 | new_map->base_error_code = src->base_error_code; |
98 | *dest = new_map; |
99 | return 0; |
100 | } |
101 | |
102 | void ext2fs_set_bitmap_padding(ext2fs_generic_bitmap map) |
103 | { |
104 | __u32 i, j; |
105 | |
106 | for (i=map->end+1, j = i - map->start; i <= map->real_end; i++, j++) |
107 | ext2fs_set_bit(j, map->bitmap); |
108 | } |
109 | |
110 | errcode_t ext2fs_allocate_inode_bitmap(ext2_filsys fs, |
111 | const char *descr, |
112 | ext2fs_inode_bitmap *ret) |
113 | { |
114 | ext2fs_inode_bitmap bitmap; |
115 | errcode_t retval; |
116 | __u32 start, end, real_end; |
117 | |
118 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
119 | |
120 | fs->write_bitmaps = ext2fs_write_bitmaps; |
121 | |
122 | start = 1; |
123 | end = fs->super->s_inodes_count; |
124 | real_end = (EXT2_INODES_PER_GROUP(fs->super) * fs->group_desc_count); |
125 | |
126 | retval = ext2fs_allocate_generic_bitmap(start, end, real_end, |
127 | descr, &bitmap); |
128 | if (retval) |
129 | return retval; |
130 | |
131 | bitmap->magic = EXT2_ET_MAGIC_INODE_BITMAP; |
132 | bitmap->fs = fs; |
133 | bitmap->base_error_code = EXT2_ET_BAD_INODE_MARK; |
134 | |
135 | *ret = bitmap; |
136 | return 0; |
137 | } |
138 | |
139 | errcode_t ext2fs_allocate_block_bitmap(ext2_filsys fs, |
140 | const char *descr, |
141 | ext2fs_block_bitmap *ret) |
142 | { |
143 | ext2fs_block_bitmap bitmap; |
144 | errcode_t retval; |
145 | __u32 start, end, real_end; |
146 | |
147 | EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
148 | |
149 | fs->write_bitmaps = ext2fs_write_bitmaps; |
150 | |
151 | start = fs->super->s_first_data_block; |
152 | end = fs->super->s_blocks_count-1; |
153 | real_end = (EXT2_BLOCKS_PER_GROUP(fs->super) |
154 | * fs->group_desc_count)-1 + start; |
155 | |
156 | retval = ext2fs_allocate_generic_bitmap(start, end, real_end, |
157 | descr, &bitmap); |
158 | if (retval) |
159 | return retval; |
160 | |
161 | bitmap->magic = EXT2_ET_MAGIC_BLOCK_BITMAP; |
162 | bitmap->fs = fs; |
163 | bitmap->base_error_code = EXT2_ET_BAD_BLOCK_MARK; |
164 | |
165 | *ret = bitmap; |
166 | return 0; |
167 | } |
168 | |
169 | errcode_t ext2fs_fudge_inode_bitmap_end(ext2fs_inode_bitmap bitmap, |
170 | ext2_ino_t end, ext2_ino_t *oend) |
171 | { |
172 | EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_INODE_BITMAP); |
173 | |
174 | if (end > bitmap->real_end) |
175 | return EXT2_ET_FUDGE_INODE_BITMAP_END; |
176 | if (oend) |
177 | *oend = bitmap->end; |
178 | bitmap->end = end; |
179 | return 0; |
180 | } |
181 | |
182 | errcode_t ext2fs_fudge_block_bitmap_end(ext2fs_block_bitmap bitmap, |
183 | blk_t end, blk_t *oend) |
184 | { |
185 | EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_BLOCK_BITMAP); |
186 | |
187 | if (end > bitmap->real_end) |
188 | return EXT2_ET_FUDGE_BLOCK_BITMAP_END; |
189 | if (oend) |
190 | *oend = bitmap->end; |
191 | bitmap->end = end; |
192 | return 0; |
193 | } |
194 | |
195 | void ext2fs_clear_inode_bitmap(ext2fs_inode_bitmap bitmap) |
196 | { |
197 | if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_INODE_BITMAP)) |
198 | return; |
199 | |
200 | memset(bitmap->bitmap, 0, |
201 | (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1)); |
202 | } |
203 | |
204 | void ext2fs_clear_block_bitmap(ext2fs_block_bitmap bitmap) |
205 | { |
206 | if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_BLOCK_BITMAP)) |
207 | return; |
208 | |
209 | memset(bitmap->bitmap, 0, |
210 | (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1)); |
211 | } |
212 |