static int is_freespace(struct cfdisk *cf, size_t i)
{
struct fdisk_partition *pa;
assert(cf);
assert(cf->table);
pa = fdisk_table_get_partition(cf->table, i);
return fdisk_partition_is_freespace(pa);
}
/*
* Verify that area addressed by @start is freespace or the @cur[rent]
* partition and continue to the next table entries until it's freespace, and
* counts size of all this space.
*
* This is core of the partition start offset move operation. We can move the
* start within the current partition of to the another free space. It's
* forbidden to move start of the partition to another already defined
* partition.
*/
static int resize_get_last_possible(
struct fdisk_table *tb,
struct fdisk_partition *cur,
fdisk_sector_t start,
fdisk_sector_t *maxsz)
{
struct fdisk_partition *pa = NULL, *last = NULL;
struct fdisk_iter itr;
fdisk_reset_iter(&itr, FDISK_ITER_FORWARD);
*maxsz = 0;
while (fdisk_table_next_partition(tb, &itr, &pa) == 0) {
if (!fdisk_partition_has_start(pa) ||
!fdisk_partition_has_size(pa) ||
fdisk_partition_is_container(pa))
continue;
if (!last) {
if (start >= pa->start && start < pa->start + pa->size) {
if (fdisk_partition_is_freespace(pa) || pa == cur)
last = pa;
else
break;
*maxsz = pa->size - (pa->start - start);
}
} else if (!fdisk_partition_is_freespace(pa) && pa != cur) {
break;
} else {
last = pa;
*maxsz += pa->size;
}
}
if (last)
DBG(PART, ul_debugobj(cur, "resize: max size=%ju", (uintmax_t) *maxsz));
return last ? 0 : -1;
}
/*
* Uses template @tpl to recount start and size change of the partition @res. The
* @tpl->size and @tpl->start are interpreted as relative to the current setting.
*/
static int recount_resize(
struct fdisk_context *cxt, size_t partno,
struct fdisk_partition *res, struct fdisk_partition *tpl)
{
fdisk_sector_t start, size;
struct fdisk_partition *cur = NULL;
struct fdisk_table *tb = NULL;
int rc;
DBG(PART, ul_debugobj(tpl, "resize requested"));
FDISK_INIT_UNDEF(start);
FDISK_INIT_UNDEF(size);
rc = fdisk_get_partitions(cxt, &tb);
if (!rc)
rc = fdisk_get_freespaces(cxt, &tb);
if (rc)
return rc;
cur = fdisk_table_get_partition_by_partno(tb, partno);
if (!cur) {
fdisk_unref_table(tb);
return -EINVAL;
}
/* 1a) set new start - change relative to the current on-disk setting */
if (tpl->movestart && fdisk_partition_has_start(tpl)) {
start = fdisk_partition_get_start(cur);
if (tpl->movestart == FDISK_MOVE_DOWN) {
if (fdisk_partition_get_start(tpl) > start)
goto erange;
start -= fdisk_partition_get_start(tpl);
} else
start += fdisk_partition_get_start(tpl);
/* 1b) set new start - absolute number */
} else if (fdisk_partition_has_start(tpl))
start = fdisk_partition_get_start(tpl);
/* 2) verify that start is within the current partition or any freespace area */
if (!FDISK_IS_UNDEF(start)) {
struct fdisk_partition *area = resize_get_by_offset(tb, start);
if (area == cur)
DBG(PART, ul_debugobj(tpl, "resize: start points to the current partition"));
else if (area && fdisk_partition_is_freespace(area))
DBG(PART, ul_debugobj(tpl, "resize: start points to freespace"));
else if (!area && start >= cxt->first_lba && start < cxt->first_lba + (cxt->grain / cxt->sector_size))
DBG(PART, ul_debugobj(tpl, "resize: start points before first partition"));
else
goto erange;
} else {
/* no change, start points to the current partition */
start = fdisk_partition_get_start(cur);
}
/* 3a) set new size -- reduce */
if (tpl->resize == FDISK_RESIZE_REDUCE && fdisk_partition_has_size(tpl)) {
DBG(PART, ul_debugobj(tpl, "resize: reduce"));
size = fdisk_partition_get_size(cur);
if (fdisk_partition_get_size(tpl) > size)
goto erange;
size -= fdisk_partition_get_size(tpl);
/* 3b) set new size -- enlarge */
} else if (tpl->resize == FDISK_RESIZE_ENLARGE && fdisk_partition_has_size(tpl)) {
DBG(PART, ul_debugobj(tpl, "resize: enlarge"));
size = fdisk_partition_get_size(cur);
size += fdisk_partition_get_size(tpl);
/* 3c) set new size -- no size specified, enlarge to all freespace */
} else if (tpl->resize == FDISK_RESIZE_ENLARGE) {
DBG(PART, ul_debugobj(tpl, "resize: enlarge to all possible"));
if (resize_get_last_possible(tb, cur, start, &size))
goto erange;
/* 3d) set new size -- absolute number */
} else if (fdisk_partition_has_size(tpl)) {
DBG(PART, ul_debugobj(tpl, "resize: new absolute size"));
size = fdisk_partition_get_size(tpl);
}
/* 4) verify that size is within the current partition or next free space */
if (!FDISK_IS_UNDEF(size)) {
fdisk_sector_t maxsz;
if (resize_get_last_possible(tb, cur, start, &maxsz))
goto erange;
DBG(PART, ul_debugobj(tpl, "resize: size wanted=%ju, max=%ju",
(uintmax_t) size, (uintmax_t) maxsz));
if (size > maxsz)
goto erange;
}
DBG(PART, ul_debugobj(tpl, "resize: SUCCESS: start %ju->%ju; size %ju->%ju",
(uintmax_t) fdisk_partition_get_start(cur), (uintmax_t) start,
(uintmax_t) fdisk_partition_get_size(cur), (uintmax_t) size));
res->start = start;
res->size = size;
fdisk_unref_table(tb);
return 0;
erange:
DBG(PART, ul_debugobj(tpl, "resize: FAILED"));
fdisk_warnx(cxt, _("Failed to resize partition #%zu."), partno + 1);
fdisk_unref_table(tb);
return -ERANGE;
}
