debian/patches/pve/0054-migration-block-dirty-bitmap-fix-larger-granularity-.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Stefan Reiter <s.reiter@proxmox.com>
   3 Date: Thu, 22 Oct 2020 17:34:17 +0200
   4 Subject: [PATCH] migration/block-dirty-bitmap: fix larger granularity bitmaps
   5
   6 sectors_per_chunk is a 64 bit integer, but the calculation would be done
   7 in 32 bits, leading to an overflow for coarse bitmap granularities.
   8
   9 If that results in the value 0, it leads to a hang where no progress is
  10 made but send_bitmap_bits is constantly called with nr_sectors being 0.
  11
  12 Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
  13 Reviewed-by: Eric Blake <eblake@redhat.com>
  14 Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
  15 ---
  16  migration/block-dirty-bitmap.c | 3 ++-
  17  1 file changed, 2 insertions(+), 1 deletion(-)
  18
  19 diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
  20 index 784330ebe1..5bf0d9fbc6 100644
  21 --- a/migration/block-dirty-bitmap.c
  22 +++ b/migration/block-dirty-bitmap.c
  23 @@ -334,8 +334,9 @@ static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs,
  24          dbms->node_name = bs_name;
  25          dbms->bitmap = bitmap;
  26          dbms->total_sectors = bdrv_nb_sectors(bs);
  27 -        dbms->sectors_per_chunk = CHUNK_SIZE * 8 *
  28 +        dbms->sectors_per_chunk = CHUNK_SIZE * 8LLU *
  29              bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
  30 +        assert(dbms->sectors_per_chunk != 0);
  31          if (bdrv_dirty_bitmap_enabled(bitmap)) {
  32              dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_ENABLED;
  33          }