1 /*
2 * rw_bitmaps.c --- routines to read and write the inode and block bitmaps.
3 *
4 * Copyright (C) 1993, 1994, 1994, 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 #include <string.h>
14 #if HAVE_UNISTD_H
15 #include <unistd.h>
16 #endif
17 #include <fcntl.h>
18 #include <time.h>
19 #ifdef HAVE_SYS_STAT_H
20 #include <sys/stat.h>
21 #endif
22 #ifdef HAVE_SYS_TYPES_H
23 #include <sys/types.h>
24 #endif
25
26 #include "ext2_fs.h"
27 #include "ext2fs.h"
28 #include "e2image.h"
29
write_bitmaps(ext2_filsys fs,int do_inode,int do_block)30 static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
31 {
32 dgrp_t i;
33 unsigned int j;
34 int block_nbytes, inode_nbytes;
35 unsigned int nbits;
36 errcode_t retval;
37 char *block_buf = NULL, *inode_buf = NULL;
38 int csum_flag = 0;
39 blk64_t blk;
40 blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
41 ext2_ino_t ino_itr = 1;
42
43 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
44
45 if (!(fs->flags & EXT2_FLAG_RW))
46 return EXT2_ET_RO_FILSYS;
47
48 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
49 EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
50 csum_flag = 1;
51
52 inode_nbytes = block_nbytes = 0;
53 if (do_block) {
54 block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
55 retval = io_channel_alloc_buf(fs->io, 0, &block_buf);
56 if (retval)
57 goto errout;
58 memset(block_buf, 0xff, fs->blocksize);
59 }
60 if (do_inode) {
61 inode_nbytes = (size_t)
62 ((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);
63 retval = io_channel_alloc_buf(fs->io, 0, &inode_buf);
64 if (retval)
65 goto errout;
66 memset(inode_buf, 0xff, fs->blocksize);
67 }
68
69 for (i = 0; i < fs->group_desc_count; i++) {
70 if (!do_block)
71 goto skip_block_bitmap;
72
73 if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT)
74 )
75 goto skip_this_block_bitmap;
76
77 retval = ext2fs_get_block_bitmap_range2(fs->block_map,
78 blk_itr, block_nbytes << 3, block_buf);
79 if (retval)
80 goto errout;
81
82 if (i == fs->group_desc_count - 1) {
83 /* Force bitmap padding for the last group */
84 nbits = EXT2FS_NUM_B2C(fs,
85 ((ext2fs_blocks_count(fs->super)
86 - (__u64) fs->super->s_first_data_block)
87 % (__u64) EXT2_BLOCKS_PER_GROUP(fs->super)));
88 if (nbits)
89 for (j = nbits; j < fs->blocksize * 8; j++)
90 ext2fs_set_bit(j, block_buf);
91 }
92 blk = ext2fs_block_bitmap_loc(fs, i);
93 if (blk) {
94 retval = io_channel_write_blk64(fs->io, blk, 1,
95 block_buf);
96 if (retval) {
97 retval = EXT2_ET_BLOCK_BITMAP_WRITE;
98 goto errout;
99 }
100 }
101 skip_this_block_bitmap:
102 blk_itr += block_nbytes << 3;
103 skip_block_bitmap:
104
105 if (!do_inode)
106 continue;
107
108 if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT)
109 )
110 goto skip_this_inode_bitmap;
111
112 retval = ext2fs_get_inode_bitmap_range2(fs->inode_map,
113 ino_itr, inode_nbytes << 3, inode_buf);
114 if (retval)
115 goto errout;
116
117 blk = ext2fs_inode_bitmap_loc(fs, i);
118 if (blk) {
119 retval = io_channel_write_blk64(fs->io, blk, 1,
120 inode_buf);
121 if (retval) {
122 retval = EXT2_ET_INODE_BITMAP_WRITE;
123 goto errout;
124 }
125 }
126 skip_this_inode_bitmap:
127 ino_itr += inode_nbytes << 3;
128
129 }
130 if (do_block) {
131 fs->flags &= ~EXT2_FLAG_BB_DIRTY;
132 ext2fs_free_mem(&block_buf);
133 }
134 if (do_inode) {
135 fs->flags &= ~EXT2_FLAG_IB_DIRTY;
136 ext2fs_free_mem(&inode_buf);
137 }
138 return 0;
139 errout:
140 if (inode_buf)
141 ext2fs_free_mem(&inode_buf);
142 if (block_buf)
143 ext2fs_free_mem(&block_buf);
144 return retval;
145 }
146
read_bitmaps(ext2_filsys fs,int do_inode,int do_block)147 static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
148 {
149 dgrp_t i;
150 char *block_bitmap = 0, *inode_bitmap = 0;
151 char *buf;
152 errcode_t retval;
153 int block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
154 int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
155 int csum_flag = 0;
156 unsigned int cnt;
157 blk64_t blk;
158 blk64_t blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
159 blk64_t blk_cnt;
160 ext2_ino_t ino_itr = 1;
161 ext2_ino_t ino_cnt;
162
163 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
164
165 if ((block_nbytes > (int) fs->blocksize) ||
166 (inode_nbytes > (int) fs->blocksize))
167 return EXT2_ET_CORRUPT_SUPERBLOCK;
168
169 fs->write_bitmaps = ext2fs_write_bitmaps;
170
171 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
172 EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
173 csum_flag = 1;
174
175 retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
176 if (retval)
177 return retval;
178 if (do_block) {
179 if (fs->block_map)
180 ext2fs_free_block_bitmap(fs->block_map);
181 strcpy(buf, "block bitmap for ");
182 strcat(buf, fs->device_name);
183 retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
184 if (retval)
185 goto cleanup;
186 retval = io_channel_alloc_buf(fs->io, 0, &block_bitmap);
187 if (retval)
188 goto cleanup;
189 } else
190 block_nbytes = 0;
191 if (do_inode) {
192 if (fs->inode_map)
193 ext2fs_free_inode_bitmap(fs->inode_map);
194 strcpy(buf, "inode bitmap for ");
195 strcat(buf, fs->device_name);
196 retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
197 if (retval)
198 goto cleanup;
199 retval = io_channel_alloc_buf(fs->io, 0, &inode_bitmap);
200 if (retval)
201 goto cleanup;
202 } else
203 inode_nbytes = 0;
204 ext2fs_free_mem(&buf);
205
206 if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
207 blk = (fs->image_header->offset_inodemap / fs->blocksize);
208 ino_cnt = fs->super->s_inodes_count;
209 while (inode_nbytes > 0) {
210 retval = io_channel_read_blk64(fs->image_io, blk++,
211 1, inode_bitmap);
212 if (retval)
213 goto cleanup;
214 cnt = fs->blocksize << 3;
215 if (cnt > ino_cnt)
216 cnt = ino_cnt;
217 retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
218 ino_itr, cnt, inode_bitmap);
219 if (retval)
220 goto cleanup;
221 ino_itr += fs->blocksize << 3;
222 ino_cnt -= fs->blocksize << 3;
223 inode_nbytes -= fs->blocksize;
224 }
225 blk = (fs->image_header->offset_blockmap /
226 fs->blocksize);
227 blk_cnt = (blk64_t)EXT2_CLUSTERS_PER_GROUP(fs->super) *
228 fs->group_desc_count;
229 while (block_nbytes > 0) {
230 retval = io_channel_read_blk64(fs->image_io, blk++,
231 1, block_bitmap);
232 if (retval)
233 goto cleanup;
234 cnt = fs->blocksize << 3;
235 if (cnt > blk_cnt)
236 cnt = blk_cnt;
237 retval = ext2fs_set_block_bitmap_range2(fs->block_map,
238 blk_itr, cnt, block_bitmap);
239 if (retval)
240 goto cleanup;
241 blk_itr += fs->blocksize << 3;
242 blk_cnt -= fs->blocksize << 3;
243 block_nbytes -= fs->blocksize;
244 }
245 goto success_cleanup;
246 }
247
248 for (i = 0; i < fs->group_desc_count; i++) {
249 if (block_bitmap) {
250 blk = ext2fs_block_bitmap_loc(fs, i);
251 if (csum_flag &&
252 ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) &&
253 ext2fs_group_desc_csum_verify(fs, i))
254 blk = 0;
255 if (blk) {
256 retval = io_channel_read_blk64(fs->io, blk,
257 1, block_bitmap);
258 if (retval) {
259 retval = EXT2_ET_BLOCK_BITMAP_READ;
260 goto cleanup;
261 }
262 } else
263 memset(block_bitmap, 0, block_nbytes);
264 cnt = block_nbytes << 3;
265 retval = ext2fs_set_block_bitmap_range2(fs->block_map,
266 blk_itr, cnt, block_bitmap);
267 if (retval)
268 goto cleanup;
269 blk_itr += block_nbytes << 3;
270 }
271 if (inode_bitmap) {
272 blk = ext2fs_inode_bitmap_loc(fs, i);
273 if (csum_flag &&
274 ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) &&
275 ext2fs_group_desc_csum_verify(fs, i))
276 blk = 0;
277 if (blk) {
278 retval = io_channel_read_blk64(fs->io, blk,
279 1, inode_bitmap);
280 if (retval) {
281 retval = EXT2_ET_INODE_BITMAP_READ;
282 goto cleanup;
283 }
284 } else
285 memset(inode_bitmap, 0, inode_nbytes);
286 cnt = inode_nbytes << 3;
287 retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
288 ino_itr, cnt, inode_bitmap);
289 if (retval)
290 goto cleanup;
291 ino_itr += inode_nbytes << 3;
292 }
293 }
294 success_cleanup:
295 if (inode_bitmap)
296 ext2fs_free_mem(&inode_bitmap);
297 if (block_bitmap)
298 ext2fs_free_mem(&block_bitmap);
299 return 0;
300
301 cleanup:
302 if (do_block) {
303 ext2fs_free_mem(&fs->block_map);
304 fs->block_map = 0;
305 }
306 if (do_inode) {
307 ext2fs_free_mem(&fs->inode_map);
308 fs->inode_map = 0;
309 }
310 if (inode_bitmap)
311 ext2fs_free_mem(&inode_bitmap);
312 if (block_bitmap)
313 ext2fs_free_mem(&block_bitmap);
314 if (buf)
315 ext2fs_free_mem(&buf);
316 return retval;
317 }
318
ext2fs_read_inode_bitmap(ext2_filsys fs)319 errcode_t ext2fs_read_inode_bitmap(ext2_filsys fs)
320 {
321 return read_bitmaps(fs, 1, 0);
322 }
323
ext2fs_read_block_bitmap(ext2_filsys fs)324 errcode_t ext2fs_read_block_bitmap(ext2_filsys fs)
325 {
326 return read_bitmaps(fs, 0, 1);
327 }
328
ext2fs_write_inode_bitmap(ext2_filsys fs)329 errcode_t ext2fs_write_inode_bitmap(ext2_filsys fs)
330 {
331 return write_bitmaps(fs, 1, 0);
332 }
333
ext2fs_write_block_bitmap(ext2_filsys fs)334 errcode_t ext2fs_write_block_bitmap (ext2_filsys fs)
335 {
336 return write_bitmaps(fs, 0, 1);
337 }
338
ext2fs_read_bitmaps(ext2_filsys fs)339 errcode_t ext2fs_read_bitmaps(ext2_filsys fs)
340 {
341 if (fs->inode_map && fs->block_map)
342 return 0;
343
344 return read_bitmaps(fs, !fs->inode_map, !fs->block_map);
345 }
346
ext2fs_write_bitmaps(ext2_filsys fs)347 errcode_t ext2fs_write_bitmaps(ext2_filsys fs)
348 {
349 int do_inode = fs->inode_map && ext2fs_test_ib_dirty(fs);
350 int do_block = fs->block_map && ext2fs_test_bb_dirty(fs);
351
352 if (!do_inode && !do_block)
353 return 0;
354
355 return write_bitmaps(fs, do_inode, do_block);
356 }
357