Re: [PATCH 14/21] parallels: accept multiple clusters in mark_used()

[Alexander Ivanov]

On 9/15/23 20:41, Denis V. Lunev wrote:
> This would be useful in the next patch in allocate_clusters(). This
> change would not imply serious performance drawbacks as usually image
> is full of data or are at the end of the bitmap.
>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> ---
>   block/parallels.c | 18 ++++++++++--------
>   1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/block/parallels.c b/block/parallels.c
> index 2517f35581..a2ba5a9353 100644
> --- a/block/parallels.c
> +++ b/block/parallels.c
> @@ -178,18 +178,20 @@ 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)
> +static int mark_used(BlockDriverState *bs, unsigned long *bitmap,
> +                     uint32_t bitmap_size, int64_t off, uint32_t count)
>   {
>       BDRVParallelsState *s = bs->opaque;
>       uint32_t cluster_index = host_cluster_index(s, off);
> -    if (cluster_index >= bitmap_size) {
> +    unsigned long next_used;
> +    if (cluster_index + count > bitmap_size) {
>           return -E2BIG;
>       }
> -    if (test_bit(cluster_index, bitmap)) {
> +    next_used = find_next_bit(bitmap, bitmap_size, cluster_index);
> +    if (next_used < cluster_index + count) {
>           return -EBUSY;
>       }
> -    bitmap_set(bitmap, cluster_index, 1);
> +    bitmap_set(bitmap, cluster_index, count);
>       return 0;
>   }
>   
> @@ -230,7 +232,7 @@ static int parallels_fill_used_bitmap(BlockDriverState *bs)
>               continue;
>           }
>   
> -        err2 = mark_used(bs, s->used_bmap, s->used_bmap_size, host_off);
> +        err2 = mark_used(bs, s->used_bmap, s->used_bmap_size, host_off, 1);
>           if (err2 < 0 && err == 0) {
>               err = err2;
>           }
> @@ -732,7 +734,7 @@ parallels_check_duplicate(BlockDriverState *bs, 
> BdrvCheckResult *res,
>               continue;
>           }
>   
> -        ret = mark_used(bs, bitmap, bitmap_size, host_off);
> +        ret = mark_used(bs, bitmap, bitmap_size, host_off, 1);
>           assert(ret != -E2BIG);
>           if (ret == 0) {
>               continue;
> @@ -792,7 +794,7 @@ parallels_check_duplicate(BlockDriverState *bs, 
> BdrvCheckResult *res,
>            * considered, and the bitmap size doesn't change. This specifically
>            * means that -E2BIG is OK.
>            */
> -        ret = mark_used(bs, bitmap, bitmap_size, host_off);
> +        ret = mark_used(bs, bitmap, bitmap_size, host_off, 1);
>           if (ret == -EBUSY) {
>               res->check_errors++;
>               goto out_repair_bat;

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