make_ext4fs/make_ext4fs.c
Rosen Penev eebda1d55d make_ext4: Add strict prototypes.
Removes some undefined behavior.

Signed-off by: Rosen Penev <rosenp@gmail.com>
2017-05-29 08:44:46 +02:00

526 lines
14 KiB
C

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "ext4_utils.h"
#include "allocate.h"
#include "contents.h"
#include "uuid.h"
#include "wipe.h"
#include <sparse/sparse.h>
#include <assert.h>
#include <dirent.h>
#include <fcntl.h>
#include <inttypes.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <locale.h>
/* TODO: Not implemented:
Allocating blocks in the same block group as the file inode
Hash or binary tree directories
*/
static int filter_dot(const struct dirent *d)
{
return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
}
static u32 build_default_directory_structure(time_t fixed_time)
{
u32 inode;
u32 root_inode;
struct dentry dentries = {
.filename = "lost+found",
.file_type = EXT4_FT_DIR,
.mode = S_IRWXU,
.uid = 0,
.gid = 0,
.mtime = (fixed_time != -1) ? fixed_time : 0,
};
root_inode = make_directory(0, 1, &dentries, 1);
inode = make_directory(root_inode, 0, NULL, 0);
*dentries.inode = inode;
inode_set_permissions(inode, dentries.mode,
dentries.uid, dentries.gid, dentries.mtime);
return root_inode;
}
/* Read a local directory and create the same tree in the generated filesystem.
Calls itself recursively with each directory in the given directory.
full_path is an absolute or relative path, with a trailing slash, to the
directory on disk that should be copied, or NULL if this is a directory
that does not exist on disk (e.g. lost+found).
dir_path is an absolute path, with trailing slash, to the same directory
if the image were mounted at the specified mount point */
static u32 build_directory_structure(const char *full_path, const char *dir_path,
u32 dir_inode, fs_config_func_t fs_config_func,
int verbose, time_t fixed_time)
{
int entries = 0;
struct dentry *dentries;
struct dirent **namelist = NULL;
struct stat stat;
int ret;
int i;
u32 inode;
u32 entry_inode;
u32 dirs = 0;
bool needs_lost_and_found = false;
/* alphasort is locale-dependent; let's fix the locale to some sane value */
setlocale(LC_COLLATE, "C");
if (full_path) {
entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
if (entries < 0) {
#ifdef __GLIBC__
/* The scandir function implemented in glibc has a bug that makes it
erroneously fail with ENOMEM under certain circumstances.
As a workaround we can retry the scandir call with the same arguments.
GLIBC BZ: https://sourceware.org/bugzilla/show_bug.cgi?id=17804 */
if (errno == ENOMEM)
entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
#endif
if (entries < 0) {
error_errno("scandir");
return EXT4_ALLOCATE_FAILED;
}
}
}
if (dir_inode == 0) {
/* root directory, check if lost+found already exists */
for (i = 0; i < entries; i++)
if (strcmp(namelist[i]->d_name, "lost+found") == 0)
break;
if (i == entries)
needs_lost_and_found = true;
}
dentries = calloc(entries, sizeof(struct dentry));
if (dentries == NULL)
critical_error_errno("malloc");
for (i = 0; i < entries; i++) {
dentries[i].filename = strdup(namelist[i]->d_name);
if (dentries[i].filename == NULL)
critical_error_errno("strdup");
asprintf(&dentries[i].path, "%s%s", dir_path, namelist[i]->d_name);
asprintf(&dentries[i].full_path, "%s%s", full_path, namelist[i]->d_name);
free(namelist[i]);
ret = lstat(dentries[i].full_path, &stat);
if (ret < 0) {
error_errno("lstat");
i--;
entries--;
continue;
}
dentries[i].size = stat.st_size;
dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
if (fixed_time == -1) {
dentries[i].mtime = stat.st_mtime;
} else {
dentries[i].mtime = fixed_time;
}
uint64_t capabilities;
if (fs_config_func != NULL) {
unsigned int mode = 0;
unsigned int uid = 0;
unsigned int gid = 0;
int dir = S_ISDIR(stat.st_mode);
if (fs_config_func(dentries[i].path, dir, &uid, &gid, &mode, &capabilities)) {
dentries[i].mode = mode;
dentries[i].uid = uid;
dentries[i].gid = gid;
dentries[i].capabilities = capabilities;
}
}
if (S_ISREG(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_REG_FILE;
} else if (S_ISDIR(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_DIR;
dirs++;
} else if (S_ISCHR(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_CHRDEV;
} else if (S_ISBLK(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_BLKDEV;
} else if (S_ISFIFO(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_FIFO;
} else if (S_ISSOCK(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_SOCK;
} else if (S_ISLNK(stat.st_mode)) {
dentries[i].file_type = EXT4_FT_SYMLINK;
dentries[i].link = calloc(info.block_size, 1);
readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
} else {
error("unknown file type on %s", dentries[i].path);
i--;
entries--;
}
}
free(namelist);
if (needs_lost_and_found) {
/* insert a lost+found directory at the beginning of the dentries */
struct dentry *tmp = calloc(entries + 1, sizeof(struct dentry));
memset(tmp, 0, sizeof(struct dentry));
memcpy(tmp + 1, dentries, entries * sizeof(struct dentry));
dentries = tmp;
dentries[0].filename = strdup("lost+found");
asprintf(&dentries[0].path, "%slost+found", dir_path);
dentries[0].full_path = NULL;
dentries[0].size = 0;
dentries[0].mode = S_IRWXU;
dentries[0].file_type = EXT4_FT_DIR;
dentries[0].uid = 0;
dentries[0].gid = 0;
entries++;
dirs++;
}
inode = make_directory(dir_inode, entries, dentries, dirs);
for (i = 0; i < entries; i++) {
if (dentries[i].file_type == EXT4_FT_REG_FILE) {
entry_inode = make_file(dentries[i].full_path, dentries[i].size);
} else if (dentries[i].file_type == EXT4_FT_DIR) {
char *subdir_full_path = NULL;
char *subdir_dir_path;
if (dentries[i].full_path) {
ret = asprintf(&subdir_full_path, "%s/", dentries[i].full_path);
if (ret < 0)
critical_error_errno("asprintf");
}
ret = asprintf(&subdir_dir_path, "%s/", dentries[i].path);
if (ret < 0)
critical_error_errno("asprintf");
entry_inode = build_directory_structure(subdir_full_path,
subdir_dir_path, inode, fs_config_func, verbose, fixed_time);
free(subdir_full_path);
free(subdir_dir_path);
} else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
entry_inode = make_link(dentries[i].link);
} else if (dentries[i].file_type == EXT4_FT_CHRDEV ||
dentries[i].file_type == EXT4_FT_BLKDEV ||
dentries[i].file_type == EXT4_FT_SOCK ||
dentries[i].file_type == EXT4_FT_FIFO) {
entry_inode = make_special(dentries[i].full_path);
} else {
error("unknown file type on %s", dentries[i].path);
entry_inode = 0;
}
*dentries[i].inode = entry_inode;
ret = inode_set_permissions(entry_inode, dentries[i].mode,
dentries[i].uid, dentries[i].gid,
dentries[i].mtime);
if (ret)
error("failed to set permissions on %s\n", dentries[i].path);
ret = inode_set_capabilities(entry_inode, dentries[i].capabilities);
if (ret)
error("failed to set capability on %s\n", dentries[i].path);
free(dentries[i].path);
free(dentries[i].full_path);
free(dentries[i].link);
free((void *)dentries[i].filename);
}
free(dentries);
return inode;
}
static u32 compute_block_size(void)
{
return 4096;
}
static u32 compute_journal_blocks(void)
{
u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
if (journal_blocks < 1024)
journal_blocks = 1024;
if (journal_blocks > 32768)
journal_blocks = 32768;
return journal_blocks;
}
static u32 compute_blocks_per_group(void)
{
return info.block_size * 8;
}
static u32 compute_inodes(void)
{
return DIV_ROUND_UP(info.len, info.block_size) / 4;
}
static u32 compute_inodes_per_group(void)
{
u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
u32 inodes = DIV_ROUND_UP(info.inodes, block_groups);
inodes = EXT4_ALIGN(inodes, (info.block_size / info.inode_size));
/* After properly rounding up the number of inodes/group,
* make sure to update the total inodes field in the info struct.
*/
info.inodes = inodes * block_groups;
return inodes;
}
static u32 compute_bg_desc_reserve_blocks(void)
{
u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
info.block_size);
u32 bg_desc_reserve_blocks =
DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
info.block_size) - bg_desc_blocks;
if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
bg_desc_reserve_blocks = info.block_size / sizeof(u32);
return bg_desc_reserve_blocks;
}
/* return a newly-malloc'd string that is a copy of str. The new string
is guaranteed to have a trailing slash. If absolute is true, the new string
is also guaranteed to have a leading slash.
*/
static char *canonicalize_slashes(const char *str, bool absolute)
{
char *ret;
int len = strlen(str);
int newlen = len;
char *ptr;
if (len == 0) {
if (absolute)
return strdup("/");
else
return strdup("");
}
if (str[0] != '/' && absolute) {
newlen++;
}
if (str[len - 1] != '/') {
newlen++;
}
ret = malloc(newlen + 1);
if (!ret) {
critical_error("malloc");
}
ptr = ret;
if (str[0] != '/' && absolute) {
*ptr++ = '/';
}
strcpy(ptr, str);
ptr += len;
if (str[len - 1] != '/') {
*ptr++ = '/';
}
if (ptr != ret + newlen) {
critical_error("assertion failed\n");
}
*ptr = '\0';
return ret;
}
static char *canonicalize_abs_slashes(const char *str)
{
return canonicalize_slashes(str, true);
}
static char *canonicalize_rel_slashes(const char *str)
{
return canonicalize_slashes(str, false);
}
int make_ext4fs_internal(int fd, const char *_directory,
fs_config_func_t fs_config_func, int gzip,
int sparse, int crc, int wipe,
int verbose, time_t fixed_time,
FILE* block_list_file)
{
u32 root_inode_num;
u16 root_mode;
char *directory = NULL;
if (setjmp(setjmp_env))
return EXIT_FAILURE; /* Handle a call to longjmp() */
if (_directory)
directory = canonicalize_rel_slashes(_directory);
if (info.len <= 0)
info.len = get_file_size(fd);
if (info.len <= 0) {
fprintf(stderr, "Need size of filesystem\n");
return EXIT_FAILURE;
}
if (info.block_size <= 0)
info.block_size = compute_block_size();
/* Round down the filesystem length to be a multiple of the block size */
info.len &= ~((u64)info.block_size - 1);
if (info.journal_blocks == 0)
info.journal_blocks = compute_journal_blocks();
if (info.no_journal == 0)
info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
else
info.journal_blocks = 0;
if (info.blocks_per_group <= 0)
info.blocks_per_group = compute_blocks_per_group();
if (info.inodes <= 0)
info.inodes = compute_inodes();
if (info.inode_size <= 0)
info.inode_size = 256;
if (info.label == NULL)
info.label = "";
info.inodes_per_group = compute_inodes_per_group();
info.feat_compat |=
EXT4_FEATURE_COMPAT_RESIZE_INODE |
EXT4_FEATURE_COMPAT_EXT_ATTR;
info.feat_ro_compat |=
EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
EXT4_FEATURE_RO_COMPAT_LARGE_FILE |
EXT4_FEATURE_RO_COMPAT_GDT_CSUM;
info.feat_incompat |=
EXT4_FEATURE_INCOMPAT_EXTENTS |
EXT4_FEATURE_INCOMPAT_FILETYPE;
info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
printf("Creating filesystem with parameters:\n");
printf(" Size: %"PRIu64"\n", info.len);
printf(" Block size: %d\n", info.block_size);
printf(" Blocks per group: %d\n", info.blocks_per_group);
printf(" Inodes per group: %d\n", info.inodes_per_group);
printf(" Inode size: %d\n", info.inode_size);
printf(" Journal blocks: %d\n", info.journal_blocks);
printf(" Label: %s\n", info.label);
ext4_create_fs_aux_info();
printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks);
printf(" Block groups: %d\n", aux_info.groups);
printf(" Reserved blocks: %"PRIu64"\n", (aux_info.len_blocks / 100) * info.reserve_pcnt);
printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
ext4_sparse_file = sparse_file_new(info.block_size, info.len);
block_allocator_init();
ext4_fill_in_sb();
if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
error("failed to reserve first 10 inodes");
if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
ext4_create_journal_inode();
if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
ext4_create_resize_inode();
if (directory)
root_inode_num = build_directory_structure(directory, "", 0,
fs_config_func, verbose, fixed_time);
else
root_inode_num = build_default_directory_structure(fixed_time);
root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
inode_set_permissions(root_inode_num, root_mode, 0, 0,
(fixed_time != 1) ? fixed_time : 0);
ext4_update_free();
ext4_queue_sb();
if (block_list_file) {
size_t dirlen = strlen(directory);
struct block_allocation* p = get_saved_allocation_chain();
while (p) {
if (strncmp(p->filename, directory, dirlen) == 0) {
fprintf(block_list_file, "%s", p->filename + dirlen);
} else {
fprintf(block_list_file, "%s", p->filename);
}
print_blocks(block_list_file, p);
struct block_allocation* pn = p->next;
free_alloc(p);
p = pn;
}
}
printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
aux_info.sb->s_inodes_count,
aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
aux_info.sb->s_blocks_count_lo);
if (wipe && WIPE_IS_SUPPORTED) {
wipe_block_device(fd, info.len);
}
write_ext4_image(fd, gzip, sparse, crc);
sparse_file_destroy(ext4_sparse_file);
ext4_sparse_file = NULL;
free(directory);
return 0;
}