make_ext4fs.c revision 4605b3fb8a00fa37f617a8d0fe3a095d0503a845 
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 <assert.h>
26#include <dirent.h>
27#include <libgen.h>
28#include <stdio.h>
29#include <stdlib.h>
30#include <string.h>
31#include <unistd.h>
32#include <sys/stat.h>
33#include <sys/types.h>
34
35#ifdef ANDROID
36#include <private/android_filesystem_config.h>
37#endif
38
39#ifdef USE_MINGW
40
41#include <winsock2.h>
42
43/* These match the Linux definitions of these flags.
44   L_xx is defined to avoid conflicting with the win32 versions.
45*/
46#define L_S_IRUSR 00400
47#define L_S_IWUSR 00200
48#define L_S_IXUSR 00100
49#define S_IRWXU (L_S_IRUSR | L_S_IWUSR | L_S_IXUSR)
50#define S_IRGRP 00040
51#define S_IWGRP 00020
52#define S_IXGRP 00010
53#define S_IRWXG (S_IRGRP | S_IWGRP | S_IXGRP)
54#define S_IROTH 00004
55#define S_IWOTH 00002
56#define S_IXOTH 00001
57#define S_IRWXO (S_IROTH | S_IWOTH | S_IXOTH)
58#define S_ISUID 0004000
59#define S_ISGID 0002000
60#define S_ISVTX 0001000
61
62#endif
63
64/* TODO: Not implemented:
65   Allocating blocks in the same block group as the file inode
66   Hash or binary tree directories
67   Special files: sockets, devices, fifos
68 */
69
70static int filter_dot(const struct dirent *d)
71{
72	return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
73}
74
75static u32 build_default_directory_structure()
76{
77	u32 inode;
78	u32 root_inode;
79	struct dentry dentries = {
80			.filename = "lost+found",
81			.file_type = EXT4_FT_DIR,
82			.mode = S_IRWXU,
83			.uid = 0,
84			.gid = 0,
85			.mtime = 0,
86	};
87	root_inode = make_directory(0, 1, &dentries, 1);
88	inode = make_directory(root_inode, 0, NULL, 0);
89	*dentries.inode = inode;
90	inode_set_permissions(inode, dentries.mode,
91		dentries.uid, dentries.gid, dentries.mtime);
92
93	return root_inode;
94}
95
96#ifndef USE_MINGW
97/* Read a local directory and create the same tree in the generated filesystem.
98   Calls itself recursively with each directory in the given directory */
99static u32 build_directory_structure(const char *full_path, const char *dir_path,
100		u32 dir_inode, int android)
101{
102	int entries = 0;
103	struct dentry *dentries;
104	struct dirent **namelist;
105	struct stat stat;
106	int ret;
107	int i;
108	u32 inode;
109	u32 entry_inode;
110	u32 dirs = 0;
111
112	entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
113	if (entries < 0) {
114		error_errno("scandir");
115		return EXT4_ALLOCATE_FAILED;
116	}
117
118	dentries = calloc(entries, sizeof(struct dentry));
119	if (dentries == NULL)
120		critical_error_errno("malloc");
121
122	for (i = 0; i < entries; i++) {
123		dentries[i].filename = strdup(namelist[i]->d_name);
124		if (dentries[i].filename == NULL)
125			critical_error_errno("strdup");
126
127		asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
128		asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
129
130		free(namelist[i]);
131
132		ret = lstat(dentries[i].full_path, &stat);
133		if (ret < 0) {
134			error_errno("lstat");
135			i--;
136			entries--;
137			continue;
138		}
139
140		dentries[i].size = stat.st_size;
141		dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
142		dentries[i].mtime = stat.st_mtime;
143		if (android) {
144#ifdef ANDROID
145			unsigned int mode = 0;
146			unsigned int uid = 0;
147			unsigned int gid = 0;
148			int dir = S_ISDIR(stat.st_mode);
149			fs_config(dentries[i].path, dir, &uid, &gid, &mode);
150			dentries[i].mode = mode;
151			dentries[i].uid = uid;
152			dentries[i].gid = gid;
153#else
154			error("can't set android permissions - built without android support");
155#endif
156		}
157
158		if (S_ISREG(stat.st_mode)) {
159			dentries[i].file_type = EXT4_FT_REG_FILE;
160		} else if (S_ISDIR(stat.st_mode)) {
161			dentries[i].file_type = EXT4_FT_DIR;
162			dirs++;
163		} else if (S_ISCHR(stat.st_mode)) {
164			dentries[i].file_type = EXT4_FT_CHRDEV;
165		} else if (S_ISBLK(stat.st_mode)) {
166			dentries[i].file_type = EXT4_FT_BLKDEV;
167		} else if (S_ISFIFO(stat.st_mode)) {
168			dentries[i].file_type = EXT4_FT_FIFO;
169		} else if (S_ISSOCK(stat.st_mode)) {
170			dentries[i].file_type = EXT4_FT_SOCK;
171		} else if (S_ISLNK(stat.st_mode)) {
172			dentries[i].file_type = EXT4_FT_SYMLINK;
173			dentries[i].link = calloc(info.block_size, 1);
174			readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
175		} else {
176			error("unknown file type on %s", dentries[i].path);
177			i--;
178			entries--;
179		}
180	}
181	free(namelist);
182
183	inode = make_directory(dir_inode, entries, dentries, dirs);
184
185	for (i = 0; i < entries; i++) {
186		if (dentries[i].file_type == EXT4_FT_REG_FILE) {
187			entry_inode = make_file(dentries[i].full_path, dentries[i].size);
188		} else if (dentries[i].file_type == EXT4_FT_DIR) {
189			entry_inode = build_directory_structure(dentries[i].full_path,
190					dentries[i].path, inode, android);
191		} else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
192			entry_inode = make_link(dentries[i].full_path, dentries[i].link);
193		} else {
194			error("unknown file type on %s", dentries[i].path);
195			entry_inode = 0;
196		}
197		*dentries[i].inode = entry_inode;
198
199		ret = inode_set_permissions(entry_inode, dentries[i].mode,
200			dentries[i].uid, dentries[i].gid,
201			dentries[i].mtime);
202		if (ret)
203			error("failed to set permissions on %s\n", dentries[i].path);
204
205		free(dentries[i].path);
206		free(dentries[i].full_path);
207		free(dentries[i].link);
208		free((void *)dentries[i].filename);
209	}
210
211	free(dentries);
212	return inode;
213}
214#endif
215
216static u32 compute_block_size()
217{
218	return 4096;
219}
220
221static u32 compute_journal_blocks()
222{
223	u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
224	if (journal_blocks < 1024)
225		journal_blocks = 1024;
226	if (journal_blocks > 32768)
227		journal_blocks = 32768;
228	return journal_blocks;
229}
230
231static u32 compute_blocks_per_group()
232{
233	return info.block_size * 8;
234}
235
236static u32 compute_inodes()
237{
238	return DIV_ROUND_UP(info.len, info.block_size) / 4;
239}
240
241static u32 compute_inodes_per_group()
242{
243	u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
244	u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
245	u32 inodes = DIV_ROUND_UP(info.inodes, block_groups);
246	inodes = ALIGN(inodes, (info.block_size / info.inode_size));
247
248	/* After properly rounding up the number of inodes/group,
249	 * make sure to update the total inodes field in the info struct.
250	 */
251	info.inodes = inodes * block_groups;
252
253	return inodes;
254}
255
256static u32 compute_bg_desc_reserve_blocks()
257{
258	u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
259	u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
260	u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
261			info.block_size);
262
263	u32 bg_desc_reserve_blocks =
264			DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
265					info.block_size) - bg_desc_blocks;
266
267	if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
268		bg_desc_reserve_blocks = info.block_size / sizeof(u32);
269
270	return bg_desc_reserve_blocks;
271}
272
273void reset_ext4fs_info() {
274    // Reset all the global data structures used by make_ext4fs so it
275    // can be called again.
276    memset(&info, 0, sizeof(info));
277    memset(&aux_info, 0, sizeof(aux_info));
278    free_data_blocks();
279}
280
281int make_ext4fs(const char *filename, s64 len)
282{
283    reset_ext4fs_info();
284    info.len = len;
285    return make_ext4fs_internal(filename, NULL, NULL, 0, 0, 0, 0, 1, 0);
286}
287
288int make_ext4fs_internal(const char *filename, const char *directory,
289                         char *mountpoint, int android, int gzip, int sparse,
290                         int crc, int wipe, int init_itabs)
291{
292        u32 root_inode_num;
293        u16 root_mode;
294
295	if (setjmp(setjmp_env))
296		return EXIT_FAILURE; /* Handle a call to longjmp() */
297
298	if (info.len <= 0)
299		info.len = get_file_size(filename);
300
301	if (info.len <= 0) {
302		fprintf(stderr, "Need size of filesystem\n");
303                return EXIT_FAILURE;
304	}
305
306	if (info.block_size <= 0)
307		info.block_size = compute_block_size();
308
309	/* Round down the filesystem length to be a multiple of the block size */
310	info.len &= ~((u64)info.block_size - 1);
311
312	if (info.journal_blocks == 0)
313		info.journal_blocks = compute_journal_blocks();
314
315	if (info.no_journal == 0)
316		info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
317	else
318		info.journal_blocks = 0;
319
320	if (info.blocks_per_group <= 0)
321		info.blocks_per_group = compute_blocks_per_group();
322
323	if (info.inodes <= 0)
324		info.inodes = compute_inodes();
325
326	if (info.inode_size <= 0)
327		info.inode_size = 256;
328
329	if (info.label == NULL)
330		info.label = "";
331
332	info.inodes_per_group = compute_inodes_per_group();
333
334	info.feat_compat |=
335			EXT4_FEATURE_COMPAT_RESIZE_INODE;
336
337	info.feat_ro_compat |=
338			EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
339			EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
340
341	info.feat_incompat |=
342			EXT4_FEATURE_INCOMPAT_EXTENTS |
343			EXT4_FEATURE_INCOMPAT_FILETYPE;
344
345
346	info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
347
348	printf("Creating filesystem with parameters:\n");
349	printf("    Size: %llu\n", info.len);
350	printf("    Block size: %d\n", info.block_size);
351	printf("    Blocks per group: %d\n", info.blocks_per_group);
352	printf("    Inodes per group: %d\n", info.inodes_per_group);
353	printf("    Inode size: %d\n", info.inode_size);
354	printf("    Journal blocks: %d\n", info.journal_blocks);
355	printf("    Label: %s\n", info.label);
356
357	ext4_create_fs_aux_info();
358
359	printf("    Blocks: %llu\n", aux_info.len_blocks);
360	printf("    Block groups: %d\n", aux_info.groups);
361	printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
362
363	block_allocator_init();
364
365	ext4_fill_in_sb();
366
367	if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
368		error("failed to reserve first 10 inodes");
369
370	if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
371		ext4_create_journal_inode();
372
373	if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
374		ext4_create_resize_inode();
375
376#ifdef USE_MINGW
377	// Windows needs only 'create an empty fs image' functionality
378	assert(!directory);
379	root_inode_num = build_default_directory_structure();
380#else
381	if (directory)
382		root_inode_num = build_directory_structure(directory, mountpoint, 0, android);
383	else
384		root_inode_num = build_default_directory_structure();
385#endif
386
387	root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
388	inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
389
390	ext4_update_free();
391
392	if (init_itabs)
393		init_unused_inode_tables();
394
395	ext4_queue_sb();
396
397	printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
398			aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
399			aux_info.sb->s_inodes_count,
400			aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
401			aux_info.sb->s_blocks_count_lo);
402
403	write_ext4_image(filename, gzip, sparse, crc, wipe);
404
405	return 0;
406}
407