make_ext4fs.c revision b781330b1acae2e5706bbda8d81e5f7575f40e2a 
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
24#include <dirent.h>
25#include <libgen.h>
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29#include <unistd.h>
30#include <sys/stat.h>
31#include <sys/types.h>
32
33#ifdef ANDROID
34#include <private/android_filesystem_config.h>
35#endif
36
37/* TODO: Not implemented:
38   Allocating blocks in the same block group as the file inode
39   Hash or binary tree directories
40   Special files: sockets, devices, fifos
41 */
42
43static int filter_dot(const struct dirent *d)
44{
45	return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
46}
47
48static u32 build_default_directory_structure()
49{
50	u32 inode;
51	u32 root_inode;
52	struct dentry dentries = {
53			.filename = "lost+found",
54			.file_type = EXT4_FT_DIR,
55			.mode = S_IRWXU,
56			.uid = 0,
57			.gid = 0,
58			.mtime = 0,
59	};
60	root_inode = make_directory(0, 1, &dentries, 1);
61	inode = make_directory(root_inode, 0, NULL, 0);
62	*dentries.inode = inode;
63	inode_set_permissions(inode, dentries.mode,
64		dentries.uid, dentries.gid, dentries.mtime);
65
66	return root_inode;
67}
68
69/* Read a local directory and create the same tree in the generated filesystem.
70   Calls itself recursively with each directory in the given directory */
71static u32 build_directory_structure(const char *full_path, const char *dir_path,
72		u32 dir_inode, int android)
73{
74	int entries = 0;
75	struct dentry *dentries;
76	struct dirent **namelist;
77	struct stat stat;
78	int ret;
79	int i;
80	u32 inode;
81	u32 entry_inode;
82	u32 dirs = 0;
83
84	entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
85	if (entries < 0) {
86		error_errno("scandir");
87		return EXT4_ALLOCATE_FAILED;
88	}
89
90	dentries = calloc(entries, sizeof(struct dentry));
91	if (dentries == NULL)
92		critical_error_errno("malloc");
93
94	for (i = 0; i < entries; i++) {
95		dentries[i].filename = strdup(namelist[i]->d_name);
96		if (dentries[i].filename == NULL)
97			critical_error_errno("strdup");
98
99		asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
100		asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
101
102		free(namelist[i]);
103
104		ret = lstat(dentries[i].full_path, &stat);
105		if (ret < 0) {
106			error_errno("lstat");
107			i--;
108			entries--;
109			continue;
110		}
111
112		dentries[i].size = stat.st_size;
113		dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
114		dentries[i].mtime = stat.st_mtime;
115		if (android) {
116#ifdef ANDROID
117			unsigned int mode = 0;
118			unsigned int uid = 0;
119			unsigned int gid = 0;
120			int dir = S_ISDIR(stat.st_mode);
121			fs_config(dentries[i].path, dir, &uid, &gid, &mode);
122			dentries[i].mode = mode;
123			dentries[i].uid = uid;
124			dentries[i].gid = gid;
125#else
126			error("can't set android permissions - built without android support");
127#endif
128		}
129
130		if (S_ISREG(stat.st_mode)) {
131			dentries[i].file_type = EXT4_FT_REG_FILE;
132		} else if (S_ISDIR(stat.st_mode)) {
133			dentries[i].file_type = EXT4_FT_DIR;
134			dirs++;
135		} else if (S_ISCHR(stat.st_mode)) {
136			dentries[i].file_type = EXT4_FT_CHRDEV;
137		} else if (S_ISBLK(stat.st_mode)) {
138			dentries[i].file_type = EXT4_FT_BLKDEV;
139		} else if (S_ISFIFO(stat.st_mode)) {
140			dentries[i].file_type = EXT4_FT_FIFO;
141		} else if (S_ISSOCK(stat.st_mode)) {
142			dentries[i].file_type = EXT4_FT_SOCK;
143		} else if (S_ISLNK(stat.st_mode)) {
144			dentries[i].file_type = EXT4_FT_SYMLINK;
145			dentries[i].link = calloc(info.block_size, 1);
146			readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
147		} else {
148			error("unknown file type on %s", dentries[i].path);
149			i--;
150			entries--;
151		}
152	}
153	free(namelist);
154
155	inode = make_directory(dir_inode, entries, dentries, dirs);
156
157	for (i = 0; i < entries; i++) {
158		if (dentries[i].file_type == EXT4_FT_REG_FILE) {
159			entry_inode = make_file(dentries[i].full_path, dentries[i].size);
160		} else if (dentries[i].file_type == EXT4_FT_DIR) {
161			entry_inode = build_directory_structure(dentries[i].full_path,
162					dentries[i].path, inode, android);
163		} else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
164			entry_inode = make_link(dentries[i].full_path, dentries[i].link);
165		} else {
166			error("unknown file type on %s", dentries[i].path);
167			entry_inode = 0;
168		}
169		*dentries[i].inode = entry_inode;
170
171		ret = inode_set_permissions(entry_inode, dentries[i].mode,
172			dentries[i].uid, dentries[i].gid,
173			dentries[i].mtime);
174		if (ret)
175			error("failed to set permissions on %s\n", dentries[i].path);
176
177		free(dentries[i].path);
178		free(dentries[i].full_path);
179		free(dentries[i].link);
180		free((void *)dentries[i].filename);
181	}
182
183	free(dentries);
184	return inode;
185}
186
187static u32 compute_block_size()
188{
189	return 4096;
190}
191
192static u32 compute_journal_blocks()
193{
194	u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
195	if (journal_blocks < 1024)
196		journal_blocks = 1024;
197	if (journal_blocks > 32768)
198		journal_blocks = 32768;
199	return journal_blocks;
200}
201
202static u32 compute_blocks_per_group()
203{
204	return info.block_size * 8;
205}
206
207static u32 compute_inodes()
208{
209	return DIV_ROUND_UP(info.len, info.block_size) / 4;
210}
211
212static u32 compute_inodes_per_group()
213{
214	u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
215	u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
216	return DIV_ROUND_UP(info.inodes, block_groups);
217}
218
219static u32 compute_bg_desc_reserve_blocks()
220{
221	u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
222	u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
223	u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
224			info.block_size);
225
226	u32 bg_desc_reserve_blocks =
227			DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
228					info.block_size) - bg_desc_blocks;
229
230	if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
231		bg_desc_reserve_blocks = info.block_size / sizeof(u32);
232
233	return bg_desc_reserve_blocks;
234}
235
236void reset_ext4fs_info() {
237    // Reset all the global data structures used by make_ext4fs so it
238    // can be called again.
239    memset(&info, 0, sizeof(info));
240    memset(&aux_info, 0, sizeof(aux_info));
241    free_data_blocks();
242}
243
244int make_ext4fs(const char *filename, const char *directory,
245                char *mountpoint, int android, int gzip, int sparse)
246{
247        u32 root_inode_num;
248        u16 root_mode;
249
250	if (info.len == 0)
251		info.len = get_file_size(filename);
252
253	if (info.len <= 0) {
254		fprintf(stderr, "Need size of filesystem\n");
255                return EXIT_FAILURE;
256	}
257
258	if (info.block_size <= 0)
259		info.block_size = compute_block_size();
260
261	if (info.journal_blocks == 0)
262		info.journal_blocks = compute_journal_blocks();
263
264	if (info.no_journal == 0)
265		info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
266	else
267		info.journal_blocks = 0;
268
269	if (info.blocks_per_group <= 0)
270		info.blocks_per_group = compute_blocks_per_group();
271
272	if (info.inodes <= 0)
273		info.inodes = compute_inodes();
274
275	if (info.inode_size <= 0)
276		info.inode_size = 256;
277
278	if (info.label == NULL)
279		info.label = "";
280
281	info.inodes_per_group = compute_inodes_per_group();
282
283	info.feat_compat |=
284			EXT4_FEATURE_COMPAT_RESIZE_INODE;
285
286	info.feat_ro_compat |=
287			EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
288			EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
289
290	info.feat_incompat |=
291			EXT4_FEATURE_INCOMPAT_EXTENTS |
292			EXT4_FEATURE_INCOMPAT_FILETYPE;
293
294
295	info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
296
297	printf("Creating filesystem with parameters:\n");
298	printf("    Size: %llu\n", info.len);
299	printf("    Block size: %d\n", info.block_size);
300	printf("    Blocks per group: %d\n", info.blocks_per_group);
301	printf("    Inodes per group: %d\n", info.inodes_per_group);
302	printf("    Inode size: %d\n", info.inode_size);
303	printf("    Journal blocks: %d\n", info.journal_blocks);
304	printf("    Label: %s\n", info.label);
305
306	ext4_create_fs_aux_info();
307
308	printf("    Blocks: %llu\n", aux_info.len_blocks);
309	printf("    Block groups: %d\n", aux_info.groups);
310	printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
311
312	block_allocator_init();
313
314	ext4_fill_in_sb();
315
316	if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
317		error("failed to reserve first 10 inodes");
318
319	if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
320		ext4_create_journal_inode();
321
322	if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
323		ext4_create_resize_inode();
324
325	if (directory)
326		root_inode_num = build_directory_structure(directory, mountpoint, 0, android);
327	else
328		root_inode_num = build_default_directory_structure();
329
330	root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
331	inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
332
333	ext4_update_free();
334
335	ext4_queue_sb();
336
337	printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
338			aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
339			aux_info.sb->s_inodes_count,
340			aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
341			aux_info.sb->s_blocks_count_lo);
342
343	write_ext4_image(filename, gzip, sparse);
344
345	return 0;
346}
347