From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 9 Nov 2021 15:24:22 +0000 (+0100)
Subject: repart: use LESS_BY() more
X-Git-Tag: v250-rc1~320^2~4
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=184cf99a351b46f5f70353b5bffa623b84836fa1;p=thirdparty%2Fsystemd.git

repart: use LESS_BY() more
---

diff --git a/src/partition/repart.c b/src/partition/repart.c
index 62cc8ff7ae0..482ef156ef7 100644
--- a/src/partition/repart.c
+++ b/src/partition/repart.c
@@ -528,16 +528,9 @@ static int free_area_compare(FreeArea *const *a, FreeArea *const*b) {
 }
 
 static uint64_t charge_size(uint64_t total, uint64_t amount) {
-        uint64_t rounded;
-
-        assert(amount <= total);
-
         /* Subtract the specified amount from total, rounding up to multiple of 4K if there's room */
-        rounded = round_up_size(amount, 4096);
-        if (rounded >= total)
-                return 0;
-
-        return total - rounded;
+        assert(amount <= total);
+        return LESS_BY(total, round_up_size(amount, 4096));
 }
 
 static uint64_t charge_weight(uint64_t total, uint64_t amount) {
@@ -1491,11 +1484,7 @@ static int determine_current_padding(
         offset = round_up_size(offset, 4096);
         next = round_down_size(next, 4096);
 
-        if (next >= offset) /* Check again, rounding might have fucked things up */
-                *ret = next - offset;
-        else
-                *ret = 0;
-
+        *ret = LESS_BY(next, offset); /* Saturated substraction, rounding might have fucked things up */
         return 0;
 }