make_ext4fs.c revision 263eefd9fb9608432636c903423e43848e69f39d 
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#define _GNU_SOURCE
18
19#include <dirent.h>
20#include <libgen.h>
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <unistd.h>
25#include <sys/stat.h>
26#include <sys/types.h>
27
28#include "make_ext4fs.h"
29#include "output_file.h"
30#include "ext4_utils.h"
31#include "allocate.h"
32#include "contents.h"
33#include "uuid.h"
34
35#ifdef ANDROID
36#include <private/android_filesystem_config.h>
37#endif
38
39/* TODO: Not implemented:
40   Allocating blocks in the same block group as the file inode
41   Hash or binary tree directories
42   Special files: sockets, devices, fifos
43 */
44
45static int filter_dot(const struct dirent *d)
46{
47	return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
48}
49
50static u32 build_default_directory_structure()
51{
52	u32 inode;
53	u32 root_inode;
54	struct dentry dentries = {
55			.filename = "lost+found",
56			.file_type = EXT4_FT_DIR,
57			.mode = S_IRWXU,
58			.uid = 0,
59			.gid = 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
65	return root_inode;
66}
67
68/* Read a local directory and create the same tree in the generated filesystem.
69   Calls itself recursively with each directory in the given directory */
70static u32 build_directory_structure(const char *full_path, const char *dir_path,
71		u32 dir_inode, int android)
72{
73	int entries = 0;
74	struct dentry *dentries;
75	struct dirent **namelist;
76	struct stat stat;
77	int ret;
78	int i;
79	u32 inode;
80	u32 entry_inode;
81	u32 dirs = 0;
82
83	entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
84	if (entries < 0) {
85		error_errno("scandir");
86		return EXT4_ALLOCATE_FAILED;
87	}
88
89	dentries = calloc(entries, sizeof(struct dentry));
90	if (dentries == NULL)
91		critical_error_errno("malloc");
92
93	for (i = 0; i < entries; i++) {
94		dentries[i].filename = strdup(namelist[i]->d_name);
95		if (dentries[i].filename == NULL)
96			critical_error_errno("strdup");
97
98		asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
99		asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
100
101		free(namelist[i]);
102
103		ret = lstat(dentries[i].full_path, &stat);
104		if (ret < 0) {
105			error_errno("lstat");
106			i--;
107			entries--;
108			continue;
109		}
110
111		dentries[i].size = stat.st_size;
112		dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
113		if (android) {
114#ifdef ANDROID
115			unsigned int mode = 0;
116			unsigned int uid = 0;
117			unsigned int gid = 0;
118			int dir = S_ISDIR(stat.st_mode);
119			fs_config(dentries[i].path, dir, &uid, &gid, &mode);
120			dentries[i].mode = mode;
121			dentries[i].uid = uid;
122			dentries[i].gid = gid;
123#else
124			error("can't set android permissions - built without android support");
125#endif
126		}
127
128		if (S_ISREG(stat.st_mode)) {
129			dentries[i].file_type = EXT4_FT_REG_FILE;
130		} else if (S_ISDIR(stat.st_mode)) {
131			dentries[i].file_type = EXT4_FT_DIR;
132			dirs++;
133		} else if (S_ISCHR(stat.st_mode)) {
134			dentries[i].file_type = EXT4_FT_CHRDEV;
135		} else if (S_ISBLK(stat.st_mode)) {
136			dentries[i].file_type = EXT4_FT_BLKDEV;
137		} else if (S_ISFIFO(stat.st_mode)) {
138			dentries[i].file_type = EXT4_FT_FIFO;
139		} else if (S_ISSOCK(stat.st_mode)) {
140			dentries[i].file_type = EXT4_FT_SOCK;
141		} else if (S_ISLNK(stat.st_mode)) {
142			dentries[i].file_type = EXT4_FT_SYMLINK;
143			dentries[i].link = calloc(info.block_size, 1);
144			readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
145		} else {
146			error("unknown file type on %s", dentries[i].path);
147			i--;
148			entries--;
149		}
150	}
151	free(namelist);
152
153	inode = make_directory(dir_inode, entries, dentries, dirs);
154
155	for (i = 0; i < entries; i++) {
156		if (dentries[i].file_type == EXT4_FT_REG_FILE) {
157			entry_inode = make_file(dentries[i].full_path, dentries[i].size);
158		} else if (dentries[i].file_type == EXT4_FT_DIR) {
159			entry_inode = build_directory_structure(dentries[i].full_path,
160					dentries[i].path, inode, android);
161		} else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
162			entry_inode = make_link(dentries[i].full_path, dentries[i].link);
163		} else {
164			error("unknown file type on %s", dentries[i].path);
165			entry_inode = 0;
166		}
167		*dentries[i].inode = entry_inode;
168
169		ret = inode_set_permissions(entry_inode, dentries[i].mode,
170				dentries[i].uid, dentries[i].gid);
171		if (ret)
172			error("failed to set permissions on %s\n", dentries[i].path);
173
174		free(dentries[i].path);
175		free(dentries[i].full_path);
176		free(dentries[i].link);
177		free((void *)dentries[i].filename);
178	}
179
180	free(dentries);
181	return inode;
182}
183
184static u32 compute_block_size()
185{
186	return 4096;
187}
188
189static u32 compute_blocks_per_group()
190{
191	return info.block_size * 8;
192}
193
194static u32 compute_inodes()
195{
196	return DIV_ROUND_UP(info.len, info.block_size) / 4;
197}
198
199static u32 compute_inodes_per_group()
200{
201	u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
202	u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
203	return DIV_ROUND_UP(info.inodes, block_groups);
204}
205
206void reset_ext4fs_info() {
207    // Reset all the global data structures used by make_ext4fs so it
208    // can be called again.
209    memset(&info, 0, sizeof(info));
210    memset(&aux_info, 0, sizeof(aux_info));
211    free_data_blocks();
212}
213
214int make_ext4fs(const char *filename, const char *directory,
215                char *mountpoint, int android, int gzip)
216{
217        u32 root_inode_num;
218        u16 root_mode;
219
220	if (info.len == 0)
221		info.len = get_file_size(filename);
222
223	if (info.len <= 0) {
224		fprintf(stderr, "Need size of filesystem\n");
225                return EXIT_FAILURE;
226	}
227
228	if (info.journal_blocks > 0)
229		info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
230
231	if (info.block_size <= 0)
232		info.block_size = compute_block_size();
233
234	if (info.blocks_per_group <= 0)
235		info.blocks_per_group = compute_blocks_per_group();
236
237	if (info.inodes <= 0)
238		info.inodes = compute_inodes();
239
240	if (info.inode_size <= 0)
241		info.inode_size = 256;
242
243	if (info.label == NULL)
244		info.label = "";
245
246	info.inodes_per_group = compute_inodes_per_group();
247
248	info.feat_compat |=
249			EXT4_FEATURE_COMPAT_RESIZE_INODE;
250
251	info.feat_ro_compat |=
252			EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
253			EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
254
255	info.feat_incompat |=
256			EXT4_FEATURE_INCOMPAT_EXTENTS |
257			EXT4_FEATURE_INCOMPAT_FILETYPE;
258
259
260	printf("Creating filesystem with parameters:\n");
261	printf("    Size: %llu\n", info.len);
262	printf("    Block size: %d\n", info.block_size);
263	printf("    Blocks per group: %d\n", info.blocks_per_group);
264	printf("    Inodes per group: %d\n", info.inodes_per_group);
265	printf("    Inode size: %d\n", info.inode_size);
266	printf("    Label: %s\n", info.label);
267
268	ext4_create_fs_aux_info();
269
270	printf("    Blocks: %llu\n", aux_info.len_blocks);
271	printf("    Block groups: %d\n", aux_info.groups);
272	printf("    Reserved block group size: %d\n", aux_info.bg_desc_reserve_blocks);
273
274	block_allocator_init();
275
276	ext4_fill_in_sb();
277
278	if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
279		error("failed to reserve first 10 inodes");
280
281	if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
282		ext4_create_journal_inode();
283
284	if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
285		ext4_create_resize_inode();
286
287	if (directory)
288		root_inode_num = build_directory_structure(directory, mountpoint, 0, android);
289	else
290		root_inode_num = build_default_directory_structure();
291
292	root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
293	inode_set_permissions(root_inode_num, root_mode, 0, 0);
294
295	ext4_update_free();
296
297	printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
298			aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
299			aux_info.sb->s_inodes_count,
300			aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
301			aux_info.sb->s_blocks_count_lo);
302
303	write_ext4_image(filename, gzip);
304
305	return 0;
306}
307