static int extend(int input)
{
struct pstore_header *header;
unsigned long ndx;
off_t f_end;
header = pstore_header_read(input);
seek_or_die(input, 0, SEEK_END);
for (ndx = 0; ndx < header->nr_tables; ndx++) {
struct pstore_table *table = header->tables[ndx];
if (pstore_table_matches(table, table_ref)) {
if (extend_table(table, input) < 0)
return -1;
}
}
f_end = seek_or_die(input, 0, SEEK_CUR);
/*
* Write out the header again because offsets to last extents changed.
*/
seek_or_die(input, 0, SEEK_SET);
if (pstore_header_write(header, input) < 0)
die("pstore_header_write");
pstore_header_delete(header);
seek_or_die(input, f_end, SEEK_SET);
return 0;
}
/* Reads a snapshot record from a qcow2-formatted file.
*
* The function assumes the file position of 'fd' points to the beginning of a
* QcowSnapshotHeader record. When the call returns, the file position of fd is
* at the place where the next QcowSnapshotHeader should start, if there is one.
*
* C.f. QCowSnapshotHeader in block/qcow2-snapshot.c for the complete layout of
* the header.
*/
static void
snapshot_info_read( int fd, SnapshotInfo* info )
{
uint64_t start_offset = seek_or_die(fd, 0, SEEK_CUR);
uint32_t extra_data_size;
uint16_t id_str_size, name_size;
/* read fixed-length fields */
seek_or_die(fd, 12, SEEK_CUR); /* skip l1 info */
read_or_die(fd, &id_str_size, sizeof(id_str_size));
read_or_die(fd, &name_size, sizeof(name_size));
read_or_die(fd, &info->date_sec, sizeof(info->date_sec));
read_or_die(fd, &info->date_nsec, sizeof(info->date_nsec));
read_or_die(fd, &info->vm_clock_nsec, sizeof(info->vm_clock_nsec));
read_or_die(fd, &info->vm_state_size, sizeof(info->vm_state_size));
read_or_die(fd, &extra_data_size, sizeof(extra_data_size));
/* convert to host endianness */
be16_to_cpus(&id_str_size);
be16_to_cpus(&name_size);
be32_to_cpus(&info->date_sec);
be32_to_cpus(&info->date_nsec);
be64_to_cpus(&info->vm_clock_nsec);
be32_to_cpus(&info->vm_state_size);
be32_to_cpus(&extra_data_size);
be32_to_cpus(&extra_data_size);
/* read variable-length buffers*/
info->id_str = android_alloc(id_str_size + 1); // +1: manual null-termination
info->name = android_alloc(name_size + 1);
seek_or_die(fd, extra_data_size, SEEK_CUR); /* skip extra data */
read_or_die(fd, info->id_str, id_str_size);
read_or_die(fd, info->name, name_size);
info->id_str[id_str_size] = '\0';
info->name[name_size] = '\0';
/* headers are 8 byte aligned, ceil to nearest multiple of 8 */
uint64_t end_offset = seek_or_die(fd, 0, SEEK_CUR);
uint32_t total_size = end_offset - start_offset;
uint32_t aligned_size = ((total_size - 1) / 8 + 1) * 8;
/* skip to start of next record */
seek_or_die(fd, start_offset + aligned_size, SEEK_SET);
}
static int extend_column(struct pstore_column *column, int input)
{
struct pstore_extent *extent;
off_t offset;
offset = seek_or_die(input, 0, SEEK_CUR);
extent = pstore_extent_read(column, column->last_extent, input);
column->prev_extent = extent;
column->extent = pstore_extent_new(column, PSTORE_COMP_NONE);
seek_or_die(input, offset, SEEK_SET);
if (pstore_column_preallocate(column, input, extent_len) < 0)
return -1;
if (pstore_extent_write_metadata(column->extent, PSTORE_LAST_EXTENT, input) < 0)
return -1;
return 0;
}
int cmd_extend(int argc, char *argv[])
{
int input;
off_t f_size;
if (argc < 3)
usage();
parse_args(argc - 1, argv + 1);
input = open(input_file, O_RDWR);
if (input < 0)
die("Failed to open input file '%s': %s", input_file, strerror(errno));
f_size = seek_or_die(input, 0, SEEK_END);
if (posix_fallocate(input, f_size, extent_len) != 0)
die("posix_fallocate");
seek_or_die(input, 0, SEEK_SET);
if (extend(input) < 0)
die("extend failed");
f_size = seek_or_die(input, 0, SEEK_CUR);
if (ftruncate(input, f_size) != 0)
die("ftruncate");
if (fsync(input) < 0)
die("fsync");
if (close(input) < 0)
die("close");
return 0;
}