/**
* Shrink logpack header.
*
* @logh logpack header to shrink.
* @invalid_idx new logpack header's n_records must be invalid_idx.
* @pbs physical block size [byte].
* @salt checksum salt.
*/
void shrink_logpack_header(
struct walb_logpack_header *logh, unsigned int invalid_idx,
unsigned int pbs, u32 salt)
{
unsigned int i;
/* Invalidate records. */
ASSERT(invalid_idx < logh->n_records);
for (i = invalid_idx; i < logh->n_records; i++) {
log_record_init(&logh->record[i]);
}
/* Set n_records, n_padding, and total_io_size. */
logh->n_records = invalid_idx;
logh->n_padding = 0;
logh->total_io_size = 0;
for (i = 0; i < invalid_idx; i++) {
const struct walb_log_record *rec = &logh->record[i];
if (!test_bit_u32(LOG_RECORD_DISCARD, &rec->flags)) {
logh->total_io_size += capacity_pb(pbs, rec->io_size);
}
if (test_bit_u32(LOG_RECORD_PADDING, &rec->flags)) {
logh->n_padding++;
}
}
/* Calculate checksum. */
logh->checksum = 0;
logh->checksum = checksum((const u8 *)logh, pbs, salt);
ASSERT(is_valid_logpack_header_with_checksum(logh, pbs, salt));
}
/**
* Read logpack header sector from log device.
*
* @fd log device fd opened.
* @super_sectp super sector.
* @lsid logpack lsid to read.
* @logh_sect buffer to store logpack header data.
* This allocated size must be sector size.
* @salt log checksum salt.
*
* RETURN:
* ture in success, or false.
*/
bool read_logpack_header_from_wldev(
int fd, const struct walb_super_sector* super_sectp,
u64 lsid, u32 salt, struct sector_data *logh_sect)
{
/* calc offset in the ring buffer */
u64 ring_buffer_offset = get_ring_buffer_offset_2(super_sectp);
u64 ring_buffer_size = super_sectp->ring_buffer_size;
u64 off = ring_buffer_offset + lsid % ring_buffer_size;
struct walb_logpack_header *logh = get_logpack_header(logh_sect);
/* read sector */
if (!sector_read(fd, off, logh_sect)) {
LOGe("read logpack header (lsid %"PRIu64") failed.\n", lsid);
return false;
}
/* check lsid */
if (lsid != logh->logpack_lsid) {
LOGe("lsid (given %"PRIu64" read %"PRIu64") is invalid.\n",
lsid, logh->logpack_lsid);
return false;
}
if (!is_valid_logpack_header_with_checksum(
logh, super_sectp->physical_bs, salt)) {
LOGe("check logpack header failed.\n");
return false;
}
return true;
}
/**
* Read logpack header from fd.
*
* @fd file descriptor (opened, seeked)
* @pbs physical block size [byte].
* @salt checksum salt.
* @logpack logpack to be filled. (allocated size must be physical_bs).
*
* RETURN:
* true in success, or false.
*/
bool read_logpack_header(
int fd, unsigned int pbs, u32 salt,
struct walb_logpack_header* logh)
{
/* Read */
if (!read_data(fd, (u8 *)logh, pbs)) {
return false;
}
/* Check */
if (!is_valid_logpack_header_with_checksum(logh, pbs, salt)) {
return false;
}
return true;
}
/**
* Check logpack of the given lsid exists.
*
* @lsid lsid to check.
*
* @return Non-zero if valid, or 0.
*/
int walb_check_lsid_valid(struct walb_dev *wdev, u64 lsid)
{
struct sector_data *sect;
struct walb_logpack_header *logh;
u64 off;
ASSERT(wdev);
sect = sector_alloc(wdev->physical_bs, GFP_NOIO);
if (!sect) {
LOGe("walb_check_lsid_valid: alloc sector failed.\n");
goto error0;
}
ASSERT(is_same_size_sector(sect, wdev->lsuper0));
logh = get_logpack_header(sect);
spin_lock(&wdev->lsuper0_lock);
off = get_offset_of_lsid_2(get_super_sector(wdev->lsuper0), lsid);
spin_unlock(&wdev->lsuper0_lock);
if (!sector_io(READ, wdev->ldev, off, sect)) {
LOGe("walb_check_lsid_valid: read sector failed.\n");
goto error1;
}
/* Check valid logpack header. */
if (!is_valid_logpack_header_with_checksum(
logh, wdev->physical_bs, wdev->log_checksum_salt)) {
goto error1;
}
/* Check lsid. */
if (logh->logpack_lsid != lsid) {
goto error1;
}
sector_free(sect);
return 1;
error1:
sector_free(sect);
error0:
return 0;
}
