/*
* Convert a zone-3 undo offset into a zone-2 buffer offset.
*/
hammer_off_t
hammer_undo_lookup(hammer_mount_t hmp, hammer_off_t zone3_off, int *errorp)
{
hammer_volume_t root_volume;
hammer_blockmap_t undomap __debugvar;
hammer_off_t result_offset;
KKASSERT(hammer_is_zone_undo(zone3_off));
root_volume = hammer_get_root_volume(hmp, errorp);
if (*errorp)
return(0);
undomap = &hmp->blockmap[HAMMER_ZONE_UNDO_INDEX];
KKASSERT(hammer_is_zone_undo(undomap->alloc_offset));
KKASSERT(zone3_off < undomap->alloc_offset);
result_offset = hammer_xlate_to_undo(root_volume->ondisk, zone3_off);
hammer_rel_volume(root_volume, 0);
return(result_offset);
}
hammer_off_t
blockmap_lookup_save(hammer_off_t zone_offset,
hammer_blockmap_layer1_t save_layer1,
hammer_blockmap_layer2_t save_layer2,
int *errorp)
{
struct volume_info *root_volume = NULL;
hammer_volume_ondisk_t ondisk;
hammer_blockmap_t blockmap;
hammer_blockmap_t freemap;
hammer_blockmap_layer1_t layer1;
hammer_blockmap_layer2_t layer2;
struct buffer_info *buffer1 = NULL;
struct buffer_info *buffer2 = NULL;
hammer_off_t layer1_offset;
hammer_off_t layer2_offset;
hammer_off_t result_offset = HAMMER_OFF_BAD;;
int zone;
int error = 0;
if (save_layer1)
bzero(save_layer1, sizeof(*save_layer1));
if (save_layer2)
bzero(save_layer2, sizeof(*save_layer2));
zone = HAMMER_ZONE_DECODE(zone_offset);
if (zone <= HAMMER_ZONE_RAW_VOLUME_INDEX) {
error = -1;
goto done;
}
if (zone >= HAMMER_MAX_ZONES) {
error = -2;
goto done;
}
root_volume = get_root_volume();
ondisk = root_volume->ondisk;
blockmap = &ondisk->vol0_blockmap[zone];
/*
* Handle blockmap offset translations.
*/
if (hammer_is_index_record(zone)) {
result_offset = hammer_xlate_to_zone2(zone_offset);
} else if (zone == HAMMER_ZONE_UNDO_INDEX) {
if (zone_offset >= blockmap->alloc_offset) {
error = -3;
goto done;
}
result_offset = hammer_xlate_to_undo(ondisk, zone_offset);
} else {
/* assert(zone == HAMMER_ZONE_RAW_BUFFER_INDEX); */
result_offset = zone_offset;
}
/*
* The blockmap should match the requested zone (else the volume
* header is mashed).
*/
if (hammer_is_index_record(zone) &&
HAMMER_ZONE_DECODE(blockmap->alloc_offset) != zone) {
error = -4;
goto done;
}
/*
* Validate that the big-block is assigned to the zone. Also
* assign save_layer{1,2} if not NULL.
*/
freemap = &ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
/*
* Dive layer 1.
*/
layer1_offset = freemap->phys_offset +
HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
if (layer1 == NULL) {
error = -5;
goto done;
}
if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
error = -6;
goto done;
}
if (save_layer1)
*save_layer1 = *layer1;
/*
* Dive layer 2, each entry represents a big-block.
*/
layer2_offset = layer1->phys_offset +
HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
if (layer2 == NULL) {
error = -7;
goto done;
}
if (layer2->zone != zone) {
error = -8;
goto done;
}
if (save_layer2)
*save_layer2 = *layer2;
done:
rel_buffer(buffer1);
rel_buffer(buffer2);
if (errorp)
*errorp = error;
return(result_offset);
}
