[07/21] parallels: create mark_used() helper which sets bit in used bitmap

This functionality is used twice already and next patch will add more
code with it.

Signed-off-by: Denis V. Lunev <den@openvz.org>
---
 block/parallels.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

On 9/15/23 20:41, Denis V. Lunev wrote:
> This functionality is used twice already and next patch will add more
> code with it.
>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> ---
>   block/parallels.c | 34 +++++++++++++++++++++++++---------
>   1 file changed, 25 insertions(+), 9 deletions(-)
>
> diff --git a/block/parallels.c b/block/parallels.c
> index aa29df9f77..60ad41b49b 100644
> --- a/block/parallels.c
> +++ b/block/parallels.c
> @@ -178,6 +178,21 @@ static void parallels_set_bat_entry(BDRVParallelsState *s,
>       bitmap_set(s->bat_dirty_bmap, bat_entry_off(index) / s->bat_dirty_block, 1);
>   }
>   
> +static int mark_used(BlockDriverState *bs,
> +                     unsigned long *bitmap, uint32_t bitmap_size, int64_t off)
> +{
> +    BDRVParallelsState *s = bs->opaque;
> +    uint32_t cluster_index = host_cluster_index(s, off);
> +    if (cluster_index >= bitmap_size) {
> +        return -E2BIG;
> +    }
> +    if (test_bit(cluster_index, bitmap)) {
> +        return -EBUSY;
> +    }
> +    bitmap_set(bitmap, cluster_index, 1);
> +    return 0;
> +}
> +
>   static int64_t coroutine_fn GRAPH_RDLOCK
>   allocate_clusters(BlockDriverState *bs, int64_t sector_num,
>                     int nb_sectors, int *pnum)
> @@ -621,7 +636,7 @@ parallels_check_duplicate(BlockDriverState *bs, BdrvCheckResult *res,
>       BDRVParallelsState *s = bs->opaque;
>       int64_t host_off, host_sector, guest_sector;
>       unsigned long *bitmap;
> -    uint32_t i, bitmap_size, cluster_index, bat_entry;
> +    uint32_t i, bitmap_size, bat_entry;
>       int n, ret = 0;
>       uint64_t *buf = NULL;
>       bool fixed = false;
> @@ -655,10 +670,9 @@ parallels_check_duplicate(BlockDriverState *bs, BdrvCheckResult *res,
>               continue;
>           }
>   
> -        cluster_index = host_cluster_index(s, host_off);
> -        assert(cluster_index < bitmap_size);
> -        if (!test_bit(cluster_index, bitmap)) {
> -            bitmap_set(bitmap, cluster_index, 1);
> +        ret = mark_used(bs, bitmap, bitmap_size, host_off);
> +        assert(ret != -E2BIG);
> +        if (ret == 0) {
>               continue;
>           }
>   
> @@ -713,11 +727,13 @@ parallels_check_duplicate(BlockDriverState *bs, BdrvCheckResult *res,
>            * consistent for the new allocated clusters too.
>            *
>            * Note, clusters allocated outside the current image are not
> -         * considered, and the bitmap size doesn't change.
> +         * considered, and the bitmap size doesn't change. This specifically
> +         * means that -E2BIG is OK.
>            */
> -        cluster_index = host_cluster_index(s, host_off);
> -        if (cluster_index < bitmap_size) {
> -            bitmap_set(bitmap, cluster_index, 1);
> +        ret = mark_used(bs, bitmap, bitmap_size, host_off);
> +        if (ret == -EBUSY) {
> +            res->check_errors++;
> +            goto out_repair_bat;
>           }
>   
>           fixed = true;

Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>