static int read_header(struct log_c *log)
{
int r;
unsigned long ebits;
r = dm_io_sync_vm(1, &log->header_location, READ,
log->disk_header, &ebits);
if (r)
return r;
header_from_disk(&log->header, log->disk_header);
/* New log required? */
if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
log->header.magic = MIRROR_MAGIC;
log->header.version = MIRROR_DISK_VERSION;
log->header.nr_regions = 0;
}
#ifdef __LITTLE_ENDIAN
if (log->header.version == 1)
log->header.version = 2;
#endif
if (log->header.version != MIRROR_DISK_VERSION) {
DMWARN("incompatible disk log version");
return -EINVAL;
}
return 0;
}
static int read_header(struct log_c *log)
{
int r;
r = rw_header(log, READ);
if (r)
return r;
header_from_disk(&log->header, log->disk_header);
/* New log required? */
if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
log->header.magic = MIRROR_MAGIC;
log->header.version = MIRROR_DISK_VERSION;
log->header.nr_regions = 0;
}
/* Version 2 is like version 1 but always little endian on disk. */
#ifdef __LITTLE_ENDIAN
if (log->header.version == 1)
log->header.version = 2;
#endif
if (log->header.version != MIRROR_DISK_VERSION) {
DMWARN("incompatible disk log version");
return -EINVAL;
}
return 0;
}
/*
* read_log
* @lc
*
* Valid return codes:
* -EINVAL: Invalid header, bits not copied
* -EIO: Unable to read disk log
* 0: Valid header, disk bit -> lc->clean_bits
*
* Returns: 0 on success, -EXXX on failure
*/
static int read_log(struct log_c *lc)
{
struct log_header lh;
size_t bitset_size;
memset(&lh, 0, sizeof(struct log_header));
if (rw_log(lc, 0))
return -EIO; /* Failed disk read */
header_from_disk(&lh, lc->disk_buffer);
if (lh.magic != MIRROR_MAGIC)
return -EINVAL;
lc->disk_nr_regions = lh.nr_regions;
/* Read disk bits into sync_bits */
bitset_size = lc->region_count / 8;
bitset_size += (lc->region_count % 8) ? 1 : 0;
/* 'lc->clean_bits + 1' becasue dm_bitset_t leads with a uint32_t */
memcpy(lc->clean_bits + 1, (char *)lc->disk_buffer + 1024, bitset_size);
return 0;
}
static int flush_header(struct log_c *lc)
{
struct dm_io_region null_location = {
.bdev = lc->header_location.bdev,
.sector = 0,
.count = 0,
};
lc->io_req.bi_op = REQ_OP_WRITE;
lc->io_req.bi_op_flags = WRITE_FLUSH;
return dm_io(&lc->io_req, 1, &null_location, NULL);
}
static int read_header(struct log_c *log)
{
int r;
r = rw_header(log, REQ_OP_READ);
if (r)
return r;
header_from_disk(&log->header, log->disk_header);
/* New log required? */
if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
log->header.magic = MIRROR_MAGIC;
log->header.version = MIRROR_DISK_VERSION;
log->header.nr_regions = 0;
}
#ifdef __LITTLE_ENDIAN
if (log->header.version == 1)
log->header.version = 2;
#endif
if (log->header.version != MIRROR_DISK_VERSION) {
DMWARN("incompatible disk log version");
return -EINVAL;
}
return 0;
}
