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/*
* 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 "make_ext4fs.h"
#include "output_file.h"
#include "ext4_utils.h"
#include "allocate.h"
#include "contents.h"
#include "uuid.h"
#include "backed_block.h"
#include <dirent.h>
#include <libgen.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#ifdef ANDROID
#include <private/android_filesystem_config.h>
#endif
/* TODO: Not implemented:
Allocating blocks in the same block group as the file inode
Hash or binary tree directories
Special files: sockets, devices, fifos
*/
static int filter_dot(const struct dirent *d)
{
return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
}
static u32 build_default_directory_structure()
{
u32 inode;
u32 root_inode;
struct dentry dentries = {
.filename = "lost+found",
.file_type = EXT4_FT_DIR,
.mode = S_IRWXU,
.uid = 0,
.gid = 0,
.mtime = 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 */
static u32 build_directory_structure(const char *full_path, const char *dir_path,
u32 dir_inode, int android, struct selabel_handle *sehnd)
{
int entries = 0;
struct dentry *dentries;
struct dirent **namelist;
struct stat stat;
int ret;
int i;
u32 inode;
u32 entry_inode;
u32 dirs = 0;
entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
if (entries < 0) {
error_errno("scandir");
return EXT4_ALLOCATE_FAILED;
}
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);
dentries[i].mtime = stat.st_mtime;
if (android) {
#ifdef ANDROID
unsigned int mode = 0;
unsigned int uid = 0;
unsigned int gid = 0;
int dir = S_ISDIR(stat.st_mode);
fs_config(dentries[i].path, dir, &uid, &gid, &mode);
dentries[i].mode = mode;
dentries[i].uid = uid;
dentries[i].gid = gid;
#else
error("can't set android permissions - built without android support");
#endif
}
#ifdef HAVE_SELINUX
if (sehnd) {
char *sepath = NULL;
asprintf(&sepath, "/%s", dentries[i].path);
if (selabel_lookup(sehnd, &dentries[i].secon, sepath, stat.st_mode) < 0) {
error("cannot lookup security context for %s", sepath);
}
if (dentries[i].secon)
printf("Labeling %s as %s\n", sepath, dentries[i].secon);
free(sepath);
}
#endif
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);
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) {
entry_inode = build_directory_structure(dentries[i].full_path,
dentries[i].path, inode, android, sehnd);
} else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
entry_inode = make_link(dentries[i].full_path, dentries[i].link);
} 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_selinux(entry_inode, dentries[i].secon);
if (ret)
error("failed to set SELinux context 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[i].secon);
}
free(dentries);
return inode;
}
static u32 compute_block_size()
{
return 4096;
}
static u32 compute_journal_blocks()
{
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()
{
return info.block_size * 8;
}
static u32 compute_inodes()
{
return DIV_ROUND_UP(info.len, info.block_size) / 4;
}
static u32 compute_inodes_per_group()
{
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 = 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()
{
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;
}
void reset_ext4fs_info() {
// Reset all the global data structures used by make_ext4fs so it
// can be called again.
memset(&info, 0, sizeof(info));
memset(&aux_info, 0, sizeof(aux_info));
free_data_blocks();
}
int make_ext4fs(const char *filename, s64 len,
const char *mountpoint, struct selabel_handle *sehnd)
{
reset_ext4fs_info();
info.len = len;
return make_ext4fs_internal(filename, NULL, mountpoint, 0, 0, 0, 0, 1, 0, sehnd);
}
int make_ext4fs_internal(const char *filename, const char *directory,
const char *mountpoint,
int android, int gzip, int sparse,
int crc, int wipe, int init_itabs,
struct selabel_handle *sehnd)
{
u32 root_inode_num;
u16 root_mode;
if (setjmp(setjmp_env))
return EXIT_FAILURE; /* Handle a call to longjmp() */
if (info.len <= 0)
info.len = get_file_size(filename);
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;
info.feat_ro_compat |=
EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
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: %llu\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: %llu\n", aux_info.len_blocks);
printf(" Block groups: %d\n", aux_info.groups);
printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
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, mountpoint, 0, android, sehnd);
else
root_inode_num = build_default_directory_structure();
root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
#ifdef HAVE_SELINUX
if (sehnd) {
char *sepath = NULL;
char *secontext = NULL;
if (mountpoint[0] == '/')
sepath = strdup(mountpoint);
else
asprintf(&sepath, "/%s", mountpoint);
if (!sepath)
critical_error_errno("malloc");
if (selabel_lookup(sehnd, &secontext, sepath, S_IFDIR) < 0) {
error("cannot lookup security context for %s", sepath);
}
if (secontext) {
printf("Labeling %s as %s\n", sepath, secontext);
inode_set_selinux(root_inode_num, secontext);
}
free(sepath);
freecon(secontext);
}
#endif
ext4_update_free();
if (init_itabs)
init_unused_inode_tables();
ext4_queue_sb();
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);
write_ext4_image(filename, gzip, sparse, crc, wipe);
return 0;
}