Re: [PATCH v4 03/17] dump: Convert GuestPhysBlock iterators and use the filter functions

[Janis Schoetterl-Glausch <scgl@linux.ibm.com>]

On 7/26/22 11:22, Janosch Frank wrote:
> The iteration over the memblocks is hard to understand so it's about
> time to clean it up. Instead of manually grabbing the next memblock we
> can use QTAILQ_FOREACH to iterate over all memblocks.
> 
> Additionally we move the calculation of the offset and length out by
> using the dump_get_memblock_*() functions.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

Reviewed-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>

> ---
>  dump/dump.c | 51 +++++++++++----------------------------------------
>  1 file changed, 11 insertions(+), 40 deletions(-)
> 
> diff --git a/dump/dump.c b/dump/dump.c
> index 0fd7c76c1e..35b9833a00 100644
> --- a/dump/dump.c
> +++ b/dump/dump.c
> @@ -628,56 +628,27 @@ int64_t dump_get_memblock_start(GuestPhysBlock *block, int64_t filter_area_start
>      return 0;
>  }
>  
> -static int get_next_block(DumpState *s, GuestPhysBlock *block)
> -{
> -    while (1) {
> -        block = QTAILQ_NEXT(block, next);
> -        if (!block) {
> -            /* no more block */
> -            return 1;
> -        }
> -
> -        s->start = 0;
> -        s->next_block = block;
> -        if (s->has_filter) {
> -            if (block->target_start >= s->begin + s->length ||
> -                block->target_end <= s->begin) {
> -                /* This block is out of the range */
> -                continue;
> -            }
> -
> -            if (s->begin > block->target_start) {
> -                s->start = s->begin - block->target_start;
> -            }
> -        }
> -
> -        return 0;
> -    }
> -}
> -
>  /* write all memory to vmcore */
>  static void dump_iterate(DumpState *s, Error **errp)
>  {
>      ERRP_GUARD();
>      GuestPhysBlock *block;
> -    int64_t size;
> +    int64_t memblock_size, memblock_start;
>  
> -    do {
> -        block = s->next_block;
> -
> -        size = block->target_end - block->target_start;
> -        if (s->has_filter) {
> -            size -= s->start;
> -            if (s->begin + s->length < block->target_end) {
> -                size -= block->target_end - (s->begin + s->length);
> -            }
> +    QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
> +        memblock_start = dump_get_memblock_start(block, s->begin, s->length);
> +        if (memblock_start == -1) {
> +            continue;
>          }
> -        write_memory(s, block, s->start, size, errp);
> +
> +        memblock_size = dump_get_memblock_size(block, s->begin, s->length);
> +
> +        /* Write the memory to file */
> +        write_memory(s, block, memblock_start, memblock_size, errp);
>          if (*errp) {
>              return;
>          }
> -
> -    } while (!get_next_block(s, block));
> +    }
>  }
>  
>  static void create_vmcore(DumpState *s, Error **errp)