From 1052a1142d8328a77bdc5011e749619f8e73ed54 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 9 Nov 2021 16:31:48 +0100 Subject: [PATCH] repart: fix free area calculations for unaligned partitions To properly detect how much space we have to distribute we need to take into account that both the partition offset and the partition size aren't aligned. --- src/partition/repart.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/src/partition/repart.c b/src/partition/repart.c index 3ff97520056..5e6e88df94e 100644 --- a/src/partition/repart.c +++ b/src/partition/repart.c @@ -505,18 +505,21 @@ static uint64_t free_area_available_for_new_partitions(const FreeArea *a) { avail = free_area_available(a); if (a->after) { - uint64_t need, space; + uint64_t need, space_end, new_end; need = partition_min_size_with_padding(a->after); assert(a->after->offset != UINT64_MAX); assert(a->after->current_size != UINT64_MAX); - space = round_up_size(a->after->offset + a->after->current_size, 4096) - a->after->offset + avail; - if (need >= space) - return 0; + /* Calculate where the free area ends, based on the offset of the partition preceding it */ + space_end = round_up_size(a->after->offset + a->after->current_size, 4096) + avail; + + /* Calculate where the partition would end when we give it as much as it needs */ + new_end = round_up_size(a->after->offset + need, 4096); - return space - need; + /* Calculate saturated difference of the two: that's how much we have free for other partitions */ + return LESS_BY(space_end, new_end); } return avail; -- 2.47.3