hbitmap: handle set/reset with zero length

Passing zero length to these functions leads to unpredicted results.
Zero-length set/reset may occur in active-mirror, on zero-length write
(which is unlikely, but not guaranteed to never happen).

Let's just do nothing on zero-length request.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191011090711.19940-2-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2019-10-11 12:07:07 +03:00 committed by Max Reitz
parent 767de537b1
commit fed33bd175
1 changed files with 8 additions and 0 deletions

View File

@ -387,6 +387,10 @@ void hbitmap_set(HBitmap *hb, uint64_t start, uint64_t count)
uint64_t first, n;
uint64_t last = start + count - 1;
if (count == 0) {
return;
}
trace_hbitmap_set(hb, start, count,
start >> hb->granularity, last >> hb->granularity);
@ -478,6 +482,10 @@ void hbitmap_reset(HBitmap *hb, uint64_t start, uint64_t count)
uint64_t last = start + count - 1;
uint64_t gran = 1ULL << hb->granularity;
if (count == 0) {
return;
}
assert(QEMU_IS_ALIGNED(start, gran));
assert(QEMU_IS_ALIGNED(count, gran) || (start + count == hb->orig_size));