From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Stefan Reiter Date: Thu, 22 Oct 2020 17:34:17 +0200 Subject: [PATCH] migration/block-dirty-bitmap: fix larger granularity bitmaps sectors_per_chunk is a 64 bit integer, but the calculation would be done in 32 bits, leading to an overflow for coarse bitmap granularities. If that results in the value 0, it leads to a hang where no progress is made but send_bitmap_bits is constantly called with nr_sectors being 0. Reviewed-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Eric Blake Signed-off-by: Stefan Reiter --- migration/block-dirty-bitmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c index 784330ebe1..5bf0d9fbc6 100644 --- a/migration/block-dirty-bitmap.c +++ b/migration/block-dirty-bitmap.c @@ -334,8 +334,9 @@ static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs, dbms->node_name = bs_name; dbms->bitmap = bitmap; dbms->total_sectors = bdrv_nb_sectors(bs); - dbms->sectors_per_chunk = CHUNK_SIZE * 8 * + dbms->sectors_per_chunk = CHUNK_SIZE * 8LLU * bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS; + assert(dbms->sectors_per_chunk != 0); if (bdrv_dirty_bitmap_enabled(bitmap)) { dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_ENABLED; }