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-rw-r--r--contrib/android/ext2simg.c123
1 files changed, 73 insertions, 50 deletions
diff --git a/contrib/android/ext2simg.c b/contrib/android/ext2simg.c
index 017e16f..2bf76b9 100644
--- a/contrib/android/ext2simg.c
+++ b/contrib/android/ext2simg.c
@@ -24,16 +24,14 @@
#include <sparse/sparse.h>
struct {
- int crc;
- int sparse;
- int gzip;
+ bool crc;
+ bool sparse;
+ bool gzip;
char *in_file;
char *out_file;
bool overwrite_input;
} params = {
- .crc = 0,
- .sparse = 1,
- .gzip = 0,
+ .sparse = true,
};
#define ext2fs_fatal(Retval, Format, ...) \
@@ -60,39 +58,41 @@ static void usage(char *path)
static struct buf_item {
struct buf_item *next;
- void *buf[0];
+ void *buf[];
} *buf_list;
-static void add_chunk(ext2_filsys fs, struct sparse_file *s, blk_t chunk_start, blk_t chunk_end)
+/*
+ * Add @num_blks blocks, starting at index @chunk_start, of the filesystem @fs
+ * to the sparse file @s.
+ */
+static void add_chunk(ext2_filsys fs, struct sparse_file *s,
+ blk_t chunk_start, int num_blks)
{
+ uint64_t len = (uint64_t)num_blks * fs->blocksize;
+ int64_t offset = (int64_t)chunk_start * fs->blocksize;
+ struct buf_item *bi;
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 (!params.overwrite_input) {
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;
- }
+ return;
+ }
- 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);
+ /* The input file will be overwritten, so make a copy of the blocks. */
+ if (len > SIZE_MAX - sizeof(*bi))
+ sparse_fatal("filesystem is too large");
+ bi = calloc(1, sizeof(*bi) + len);
+ if (!bi)
+ sparse_fatal("out of memory");
+ bi->next = buf_list;
+ buf_list = bi;
+ retval = io_channel_read_blk64(fs->io, chunk_start, num_blks, bi->buf);
+ if (retval)
+ ext2fs_fatal(retval, "reading data from %s", params.in_file);
- if (sparse_file_add_data(s, bi->buf, len, chunk_start) < 0)
- sparse_fatal("adding data to the sparse file");
- }
+ 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)
@@ -106,13 +106,23 @@ static void free_chunks(void)
}
}
+static blk_t fs_blocks_count(ext2_filsys fs)
+{
+ blk64_t blks = ext2fs_blocks_count(fs->super);
+
+ /* libsparse assumes 32-bit block numbers. */
+ if ((blk_t)blks != blks)
+ sparse_fatal("filesystem is too large");
+ return blks;
+}
+
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;
+ blk_t fs_blks, cur_blk;
retval = ext2fs_open(in_file, 0, 0, 0, unix_io_manager, &fs);
if (retval)
@@ -122,11 +132,9 @@ static struct sparse_file *ext_to_sparse(const char *in_file)
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;
+ fs_blks = fs_blocks_count(fs);
- s = sparse_file_new(fs->blocksize, (uint64_t)fs->blocksize * (uint64_t)nb_blk);
+ s = sparse_file_new(fs->blocksize, (uint64_t)fs_blks * fs->blocksize);
if (!s)
sparse_fatal("creating sparse file");
@@ -138,24 +146,39 @@ static struct sparse_file *ext_to_sparse(const char *in_file)
* 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;
+ int32_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) {
+ /*
+ * Iterate through the filesystem's blocks, identifying "chunks" that
+ * are contiguous ranges of blocks that are in-use by the filesystem.
+ * Add each chunk to the sparse_file.
+ */
+ for (cur_blk = ext2fs_get_block_bitmap_start2(fs->block_map);
+ cur_blk < fs_blks; ++cur_blk) {
if (ext2fs_test_block_bitmap2(fs->block_map, cur_blk)) {
+ /*
+ * @cur_blk is in-use. Append it to the pending chunk
+ * if there is one, otherwise start a new chunk.
+ */
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);
+ /*
+ * Appending @cur_blk to the pending chunk made
+ * it reach the maximum length, so end it.
+ */
+ add_chunk(fs, s, chunk_start, max_blk_per_chunk);
chunk_start = -1;
}
} else if (chunk_start != -1) {
- add_chunk(fs, s, chunk_start, cur_blk);
+ /* @cur_blk is not in-use, so end the pending chunk. */
+ add_chunk(fs, s, chunk_start, cur_blk - chunk_start);
chunk_start = -1;
}
}
+ /* If there's still a pending chunk, end it. */
if (chunk_start != -1)
- add_chunk(fs, s, chunk_start, cur_blk - 1);
+ add_chunk(fs, s, chunk_start, cur_blk - chunk_start);
ext2fs_free(fs);
return s;
@@ -165,14 +188,14 @@ 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)
+ if (stat(in, &st1) == -1)
ext2fs_fatal(errno, "stat %s\n", in);
- if (lstat(out, &st2) == -1)
+ if (stat(out, &st2) == -1) {
+ if (errno == ENOENT)
+ return false;
ext2fs_fatal(errno, "stat %s\n", out);
- return st1.st_ino == st2.st_ino;
+ }
+ return st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino;
}
int main(int argc, char *argv[])
@@ -184,13 +207,13 @@ int main(int argc, char *argv[])
while ((opt = getopt(argc, argv, "czS")) != -1) {
switch(opt) {
case 'c':
- params.crc = 1;
+ params.crc = true;
break;
case 'z':
- params.gzip = 1;
+ params.gzip = true;
break;
case 'S':
- params.sparse = 0;
+ params.sparse = false;
break;
default:
usage(argv[0]);