make_ext4fs.c revision 2e905e5f2a3df605c68cb8633580c918e9f4ba71 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "make_ext4fs.h"
18#include "output_file.h"
19#include "ext4_utils.h"
20#include "allocate.h"
21#include "contents.h"
22#include "uuid.h"
23#include "backed_block.h"
24
25#include <dirent.h>
26#include <libgen.h>
27#include <stdio.h>
28#include <stdlib.h>
29#include <string.h>
30#include <unistd.h>
31#include <sys/stat.h>
32#include <sys/types.h>
33
34#ifdef ANDROID
35#include <private/android_filesystem_config.h>
36#endif
37
38/* TODO: Not implemented:
39   Allocating blocks in the same block group as the file inode
40   Hash or binary tree directories
41   Special files: sockets, devices, fifos
42 */
43
44static int filter_dot(const struct dirent *d)
45{
46	return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
47}
48
49static u32 build_default_directory_structure()
50{
51	u32 inode;
52	u32 root_inode;
53	struct dentry dentries = {
54			.filename = "lost+found",
55			.file_type = EXT4_FT_DIR,
56			.mode = S_IRWXU,
57			.uid = 0,
58			.gid = 0,
59			.mtime = 0,
60	};
61	root_inode = make_directory(0, 1, &dentries, 1);
62	inode = make_directory(root_inode, 0, NULL, 0);
63	*dentries.inode = inode;
64	inode_set_permissions(inode, dentries.mode,
65		dentries.uid, dentries.gid, dentries.mtime);
66
67	return root_inode;
68}
69
70/* Read a local directory and create the same tree in the generated filesystem.
71   Calls itself recursively with each directory in the given directory */
72static u32 build_directory_structure(const char *full_path, const char *dir_path,
73		u32 dir_inode, int android)
74{
75	int entries = 0;
76	struct dentry *dentries;
77	struct dirent **namelist;
78	struct stat stat;
79	int ret;
80	int i;
81	u32 inode;
82	u32 entry_inode;
83	u32 dirs = 0;
84
85	entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
86	if (entries < 0) {
87		error_errno("scandir");
88		return EXT4_ALLOCATE_FAILED;
89	}
90
91	dentries = calloc(entries, sizeof(struct dentry));
92	if (dentries == NULL)
93		critical_error_errno("malloc");
94
95	for (i = 0; i < entries; i++) {
96		dentries[i].filename = strdup(namelist[i]->d_name);
97		if (dentries[i].filename == NULL)
98			critical_error_errno("strdup");
99
100		asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
101		asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
102
103		free(namelist[i]);
104
105		ret = lstat(dentries[i].full_path, &stat);
106		if (ret < 0) {
107			error_errno("lstat");
108			i--;
109			entries--;
110			continue;
111		}
112
113		dentries[i].size = stat.st_size;
114		dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
115		dentries[i].mtime = stat.st_mtime;
116		if (android) {
117#ifdef ANDROID
118			unsigned int mode = 0;
119			unsigned int uid = 0;
120			unsigned int gid = 0;
121			int dir = S_ISDIR(stat.st_mode);
122			fs_config(dentries[i].path, dir, &uid, &gid, &mode);
123			dentries[i].mode = mode;
124			dentries[i].uid = uid;
125			dentries[i].gid = gid;
126#else
127			error("can't set android permissions - built without android support");
128#endif
129		}
130
131		if (S_ISREG(stat.st_mode)) {
132			dentries[i].file_type = EXT4_FT_REG_FILE;
133		} else if (S_ISDIR(stat.st_mode)) {
134			dentries[i].file_type = EXT4_FT_DIR;
135			dirs++;
136		} else if (S_ISCHR(stat.st_mode)) {
137			dentries[i].file_type = EXT4_FT_CHRDEV;
138		} else if (S_ISBLK(stat.st_mode)) {
139			dentries[i].file_type = EXT4_FT_BLKDEV;
140		} else if (S_ISFIFO(stat.st_mode)) {
141			dentries[i].file_type = EXT4_FT_FIFO;
142		} else if (S_ISSOCK(stat.st_mode)) {
143			dentries[i].file_type = EXT4_FT_SOCK;
144		} else if (S_ISLNK(stat.st_mode)) {
145			dentries[i].file_type = EXT4_FT_SYMLINK;
146			dentries[i].link = calloc(info.block_size, 1);
147			readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
148		} else {
149			error("unknown file type on %s", dentries[i].path);
150			i--;
151			entries--;
152		}
153	}
154	free(namelist);
155
156	inode = make_directory(dir_inode, entries, dentries, dirs);
157
158	for (i = 0; i < entries; i++) {
159		if (dentries[i].file_type == EXT4_FT_REG_FILE) {
160			entry_inode = make_file(dentries[i].full_path, dentries[i].size);
161		} else if (dentries[i].file_type == EXT4_FT_DIR) {
162			entry_inode = build_directory_structure(dentries[i].full_path,
163					dentries[i].path, inode, android);
164		} else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
165			entry_inode = make_link(dentries[i].full_path, dentries[i].link);
166		} else {
167			error("unknown file type on %s", dentries[i].path);
168			entry_inode = 0;
169		}
170		*dentries[i].inode = entry_inode;
171
172		ret = inode_set_permissions(entry_inode, dentries[i].mode,
173			dentries[i].uid, dentries[i].gid,
174			dentries[i].mtime);
175		if (ret)
176			error("failed to set permissions on %s\n", dentries[i].path);
177
178		free(dentries[i].path);
179		free(dentries[i].full_path);
180		free(dentries[i].link);
181		free((void *)dentries[i].filename);
182	}
183
184	free(dentries);
185	return inode;
186}
187
188static u32 compute_block_size()
189{
190	return 4096;
191}
192
193static u32 compute_journal_blocks()
194{
195	u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
196	if (journal_blocks < 1024)
197		journal_blocks = 1024;
198	if (journal_blocks > 32768)
199		journal_blocks = 32768;
200	return journal_blocks;
201}
202
203static u32 compute_blocks_per_group()
204{
205	return info.block_size * 8;
206}
207
208static u32 compute_inodes()
209{
210	return DIV_ROUND_UP(info.len, info.block_size) / 4;
211}
212
213static u32 compute_inodes_per_group()
214{
215	u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
216	u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
217	return DIV_ROUND_UP(info.inodes, block_groups);
218}
219
220static u32 compute_bg_desc_reserve_blocks()
221{
222	u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
223	u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
224	u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
225			info.block_size);
226
227	u32 bg_desc_reserve_blocks =
228			DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
229					info.block_size) - bg_desc_blocks;
230
231	if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
232		bg_desc_reserve_blocks = info.block_size / sizeof(u32);
233
234	return bg_desc_reserve_blocks;
235}
236
237void reset_ext4fs_info() {
238    // Reset all the global data structures used by make_ext4fs so it
239    // can be called again.
240    memset(&info, 0, sizeof(info));
241    memset(&aux_info, 0, sizeof(aux_info));
242    free_data_blocks();
243}
244
245int make_ext4fs(const char *filename, const char *directory,
246                char *mountpoint, int android, int gzip, int sparse,
247                int crc)
248{
249        u32 root_inode_num;
250        u16 root_mode;
251
252	if (info.len == 0)
253		info.len = get_file_size(filename);
254
255	if (info.len <= 0) {
256		fprintf(stderr, "Need size of filesystem\n");
257                return EXIT_FAILURE;
258	}
259
260	if (info.block_size <= 0)
261		info.block_size = compute_block_size();
262
263	if (info.journal_blocks == 0)
264		info.journal_blocks = compute_journal_blocks();
265
266	if (info.no_journal == 0)
267		info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
268	else
269		info.journal_blocks = 0;
270
271	if (info.blocks_per_group <= 0)
272		info.blocks_per_group = compute_blocks_per_group();
273
274	if (info.inodes <= 0)
275		info.inodes = compute_inodes();
276
277	if (info.inode_size <= 0)
278		info.inode_size = 256;
279
280	if (info.label == NULL)
281		info.label = "";
282
283	info.inodes_per_group = compute_inodes_per_group();
284
285	info.feat_compat |=
286			EXT4_FEATURE_COMPAT_RESIZE_INODE;
287
288	info.feat_ro_compat |=
289			EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
290			EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
291
292	info.feat_incompat |=
293			EXT4_FEATURE_INCOMPAT_EXTENTS |
294			EXT4_FEATURE_INCOMPAT_FILETYPE;
295
296
297	info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
298
299	printf("Creating filesystem with parameters:\n");
300	printf("    Size: %llu\n", info.len);
301	printf("    Block size: %d\n", info.block_size);
302	printf("    Blocks per group: %d\n", info.blocks_per_group);
303	printf("    Inodes per group: %d\n", info.inodes_per_group);
304	printf("    Inode size: %d\n", info.inode_size);
305	printf("    Journal blocks: %d\n", info.journal_blocks);
306	printf("    Label: %s\n", info.label);
307
308	ext4_create_fs_aux_info();
309
310	printf("    Blocks: %llu\n", aux_info.len_blocks);
311	printf("    Block groups: %d\n", aux_info.groups);
312	printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
313
314	block_allocator_init();
315
316	ext4_fill_in_sb();
317
318	if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
319		error("failed to reserve first 10 inodes");
320
321	if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
322		ext4_create_journal_inode();
323
324	if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
325		ext4_create_resize_inode();
326
327	if (directory)
328		root_inode_num = build_directory_structure(directory, mountpoint, 0, android);
329	else
330		root_inode_num = build_default_directory_structure();
331
332	root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
333	inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
334
335	ext4_update_free();
336
337	ext4_queue_sb();
338
339	printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
340			aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
341			aux_info.sb->s_inodes_count,
342			aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
343			aux_info.sb->s_blocks_count_lo);
344
345	write_ext4_image(filename, gzip, sparse, crc);
346
347	return 0;
348}
349