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/*
* Copyright (C) 2016 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 <libgen.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <ext2fs/ext2fs.h>
#include <et/com_err.h>
#include <sparse/sparse.h>
struct {
int crc;
int sparse;
int gzip;
char *in_file;
char *out_file;
bool overwrite_input;
} params = {
.crc = 0,
.sparse = 1,
.gzip = 0,
};
#define ext2fs_fatal(Retval, Format, ...) \
do { \
com_err("error", Retval, Format, __VA_ARGS__); \
exit(EXIT_FAILURE); \
} while(0)
#define sparse_fatal(Format) \
do { \
fprintf(stderr, "sparse: "Format); \
exit(EXIT_FAILURE); \
} while(0)
static void usage(char *path)
{
char *progname = basename(path);
fprintf(stderr, "%s [ options ] <image or block device> <output image>\n"
" -c include CRC block\n"
" -z gzip output\n"
" -S don't use sparse output format\n", progname);
}
static struct buf_item {
struct buf_item *next;
void *buf[0];
} *buf_list;
static void add_chunk(ext2_filsys fs, struct sparse_file *s, blk_t chunk_start, blk_t chunk_end)
{
int retval;
unsigned int nb_blk = chunk_end - chunk_start;
size_t len = nb_blk * fs->blocksize;
int64_t offset = (int64_t)chunk_start * (int64_t)fs->blocksize;
if (params.overwrite_input == false) {
if (sparse_file_add_file(s, params.in_file, offset, len, chunk_start) < 0)
sparse_fatal("adding data to the sparse file");
} else {
/*
* The input file will be overwritten, make a copy of
* the blocks
*/
struct buf_item *bi = calloc(1, sizeof(struct buf_item) + len);
if (buf_list == NULL)
buf_list = bi;
else {
bi->next = buf_list;
buf_list = bi;
}
retval = io_channel_read_blk64(fs->io, chunk_start, nb_blk, bi->buf);
if (retval < 0)
ext2fs_fatal(retval, "reading block %u - %u", chunk_start, chunk_end);
if (sparse_file_add_data(s, bi->buf, len, chunk_start) < 0)
sparse_fatal("adding data to the sparse file");
}
}
static void free_chunks(void)
{
struct buf_item *bi;
while (buf_list) {
bi = buf_list->next;
free(buf_list);
buf_list = bi;
}
}
static struct sparse_file *ext_to_sparse(const char *in_file)
{
errcode_t retval;
ext2_filsys fs;
struct sparse_file *s;
int64_t chunk_start = -1;
blk_t first_blk, last_blk, nb_blk, cur_blk;
retval = ext2fs_open(in_file, 0, 0, 0, unix_io_manager, &fs);
if (retval)
ext2fs_fatal(retval, "while reading %s", in_file);
retval = ext2fs_read_block_bitmap(fs);
if (retval)
ext2fs_fatal(retval, "while reading block bitmap of %s", in_file);
first_blk = ext2fs_get_block_bitmap_start2(fs->block_map);
last_blk = ext2fs_get_block_bitmap_end2(fs->block_map);
nb_blk = last_blk - first_blk + 1;
s = sparse_file_new(fs->blocksize, (uint64_t)fs->blocksize * (uint64_t)nb_blk);
if (!s)
sparse_fatal("creating sparse file");
/*
* The sparse format encodes the size of a chunk (and its header) in a
* 32-bit unsigned integer (UINT32_MAX)
* When writing the chunk, the library uses a single call to write().
* Linux's implementation of the 'write' syscall does not allow transfers
* larger than INT32_MAX (32-bit _and_ 64-bit systems).
* Make sure we do not create chunks larger than this limit.
*/
int64_t max_blk_per_chunk = (INT32_MAX - 12) / fs->blocksize;
/* Iter on the blocks to merge contiguous chunk */
for (cur_blk = first_blk; cur_blk <= last_blk; ++cur_blk) {
if (ext2fs_test_block_bitmap2(fs->block_map, cur_blk)) {
if (chunk_start == -1) {
chunk_start = cur_blk;
} else if (cur_blk - chunk_start + 1 == max_blk_per_chunk) {
add_chunk(fs, s, chunk_start, cur_blk);
chunk_start = -1;
}
} else if (chunk_start != -1) {
add_chunk(fs, s, chunk_start, cur_blk);
chunk_start = -1;
}
}
if (chunk_start != -1)
add_chunk(fs, s, chunk_start, cur_blk - 1);
ext2fs_free(fs);
return s;
}
static bool same_file(const char *in, const char *out)
{
struct stat st1, st2;
if (access(out, F_OK) == -1)
return false;
if (lstat(in, &st1) == -1)
ext2fs_fatal(errno, "stat %s\n", in);
if (lstat(out, &st2) == -1)
ext2fs_fatal(errno, "stat %s\n", out);
return st1.st_ino == st2.st_ino;
}
int main(int argc, char *argv[])
{
int opt;
int out_fd;
struct sparse_file *s;
while ((opt = getopt(argc, argv, "czS")) != -1) {
switch(opt) {
case 'c':
params.crc = 1;
break;
case 'z':
params.gzip = 1;
break;
case 'S':
params.sparse = 0;
break;
default:
usage(argv[0]);
exit(EXIT_FAILURE);
}
}
if (optind + 1 >= argc) {
usage(argv[0]);
exit(EXIT_FAILURE);
}
params.in_file = strdup(argv[optind++]);
params.out_file = strdup(argv[optind]);
params.overwrite_input = same_file(params.in_file, params.out_file);
s = ext_to_sparse(params.in_file);
out_fd = open(params.out_file, O_WRONLY | O_CREAT | O_TRUNC, 0664);
if (out_fd == -1)
ext2fs_fatal(errno, "opening %s\n", params.out_file);
if (sparse_file_write(s, out_fd, params.gzip, params.sparse, params.crc) < 0)
sparse_fatal("writing sparse file");
sparse_file_destroy(s);
free(params.in_file);
free(params.out_file);
free_chunks();
close(out_fd);
return 0;
}
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