static int
vhd_journal_update(vhd_journal_t *j, off_t offset,
char *buf, size_t size, uint32_t type)
{
int err;
off_t eof;
uint64_t *off, off_bak;
uint32_t *entries;
vhd_journal_entry_t entry;
entry.type = type;
entry.size = size;
entry.offset = offset;
entry.cookie = VHD_JOURNAL_ENTRY_COOKIE;
entry.checksum = vhd_journal_checksum_entry(&entry, buf, size);
err = vhd_journal_seek(j, j->header.journal_eof, SEEK_SET);
if (err)
return err;
err = vhd_journal_write_entry(j, &entry);
if (err)
goto fail;
err = vhd_journal_write(j, buf, size);
if (err)
goto fail;
if (type == VHD_JOURNAL_ENTRY_TYPE_DATA) {
off = &j->header.journal_data_offset;
entries = &j->header.journal_data_entries;
} else {
off = &j->header.journal_metadata_offset;
entries = &j->header.journal_metadata_entries;
}
off_bak = *off;
if (!(*entries)++)
*off = j->header.journal_eof;
j->header.journal_eof += (size + sizeof(vhd_journal_entry_t));
err = vhd_journal_write_header(j, &j->header);
if (err) {
if (!--(*entries))
*off = off_bak;
j->header.journal_eof -= (size + sizeof(vhd_journal_entry_t));
goto fail;
}
return 0;
fail:
if (!j->is_block)
vhd_journal_truncate(j, j->header.journal_eof);
return err;
}
/*
* commit indicates the transaction completed
* successfully and we can remove the undo log
*/
int
vhd_journal_commit(vhd_journal_t *j)
{
int err;
j->header.journal_data_entries = 0;
j->header.journal_metadata_entries = 0;
j->header.journal_data_offset = 0;
j->header.journal_metadata_offset = 0;
err = vhd_journal_write_header(j, &j->header);
if (err)
return err;
if (!j->is_block)
err = vhd_journal_truncate(j, sizeof(vhd_journal_header_t));
if (err)
return -errno;
return 0;
}
