From 2c5451ca523fc2b757e1e5b4e0b9fc84dbd58f97 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 7 Apr 2023 17:33:00 +0200 Subject: [PATCH] migration/block: replace uses of blk_nb_sectors that do not check result Uses of blk_nb_sectors must check whether the result is negative. Otherwise, underflow can happen. Fortunately, alloc_aio_bitmap() and bmds_aio_inflight() both have an alternative way to retrieve the number of sectors in the file. Signed-off-by: Paolo Bonzini Message-Id: <20230407153303.391121-6-pbonzini@redhat.com> Reviewed-by: Eric Blake Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- migration/block.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/migration/block.c b/migration/block.c index 426a25bb19..b2497bbd32 100644 --- a/migration/block.c +++ b/migration/block.c @@ -195,7 +195,7 @@ static int bmds_aio_inflight(BlkMigDevState *bmds, int64_t sector) { int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK; - if (sector < blk_nb_sectors(bmds->blk)) { + if (sector < bmds->total_sectors) { return !!(bmds->aio_bitmap[chunk / (sizeof(unsigned long) * 8)] & (1UL << (chunk % (sizeof(unsigned long) * 8)))); } else { @@ -229,10 +229,9 @@ static void bmds_set_aio_inflight(BlkMigDevState *bmds, int64_t sector_num, static void alloc_aio_bitmap(BlkMigDevState *bmds) { - BlockBackend *bb = bmds->blk; int64_t bitmap_size; - bitmap_size = blk_nb_sectors(bb) + BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1; + bitmap_size = bmds->total_sectors + BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1; bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8; bmds->aio_bitmap = g_malloc0(bitmap_size);