Re: [Qemu-devel] [PATCH] vvfat: Fix read-write mode

[Paolo Bonzini <pbonzini@redhat.com>]

On 11/08/2011 10:55 AM, Kevin Wolf wrote:
> vvfat used to directly call into the qcow2 block driver instead of using the
> block.c wrappers. With the coroutine conversion, this stopped working.
>
> Signed-off-by: Kevin Wolf<kwolf@redhat.com>
> ---
>   block/vvfat.c |   44 +++++++++++++++++++++++---------------------
>   1 files changed, 23 insertions(+), 21 deletions(-)
>
> diff --git a/block/vvfat.c b/block/vvfat.c
> index 8511fe5..131680f 100644
> --- a/block/vvfat.c
> +++ b/block/vvfat.c
> @@ -1254,15 +1254,15 @@ static int vvfat_read(BlockDriverState *bs, int64_t sector_num,
>   	   return -1;
>   	if (s->qcow) {
>   	    int n;
> -	    if (s->qcow->drv->bdrv_is_allocated(s->qcow,
> -			sector_num, nb_sectors-i,&n)) {
> +            if (bdrv_is_allocated(s->qcow, sector_num, nb_sectors-i,&n)) {
>   DLOG(fprintf(stderr, "sectors %d+%d allocated\n", (int)sector_num, n));
> -		if (s->qcow->drv->bdrv_read(s->qcow, sector_num, buf+i*0x200, n))
> -		    return -1;
> -		i += n - 1;
> -		sector_num += n - 1;
> -		continue;
> -	    }
> +                if (bdrv_read(s->qcow, sector_num, buf + i*0x200, n)) {
> +                    return -1;
> +                }
> +                i += n - 1;
> +                sector_num += n - 1;
> +                continue;
> +            }
>   DLOG(fprintf(stderr, "sector %d not allocated\n", (int)sector_num));
>   	}
>   	if(sector_num<s->faked_sectors) {
> @@ -1516,7 +1516,7 @@ static inline int cluster_was_modified(BDRVVVFATState* s, uint32_t cluster_num)
>   	return 0;
>
>       for (i = 0; !was_modified&&  i<  s->sectors_per_cluster; i++)
> -	was_modified = s->qcow->drv->bdrv_is_allocated(s->qcow,
> +	was_modified = bdrv_is_allocated(s->qcow,
>   		cluster2sector(s, cluster_num) + i, 1,&dummy);
>
>       return was_modified;
> @@ -1665,16 +1665,16 @@ static uint32_t get_cluster_count_for_direntry(BDRVVVFATState* s,
>   		int64_t offset = cluster2sector(s, cluster_num);
>
>   		vvfat_close_current_file(s);
> -		for (i = 0; i<  s->sectors_per_cluster; i++)
> -		    if (!s->qcow->drv->bdrv_is_allocated(s->qcow,
> -				offset + i, 1,&dummy)) {
> -			if (vvfat_read(s->bs,
> -				    offset, s->cluster_buffer, 1))
> -			    return -1;
> -			if (s->qcow->drv->bdrv_write(s->qcow,
> -				    offset, s->cluster_buffer, 1))
> -			    return -2;
> -		    }
> +                for (i = 0; i<  s->sectors_per_cluster; i++) {
> +                    if (!bdrv_is_allocated(s->qcow, offset + i, 1,&dummy)) {
> +                        if (vvfat_read(s->bs, offset, s->cluster_buffer, 1)) {
> +                            return -1;
> +                        }
> +                        if (bdrv_write(s->qcow, offset, s->cluster_buffer, 1)) {
> +                            return -2;
> +                        }
> +                    }
> +                }
>   	    }
>   	}
>
> @@ -2619,7 +2619,9 @@ static int do_commit(BDRVVVFATState* s)
>   	return ret;
>       }
>
> -    s->qcow->drv->bdrv_make_empty(s->qcow);
> +    if (s->qcow->drv->bdrv_make_empty) {
> +        s->qcow->drv->bdrv_make_empty(s->qcow);
> +    }
>
>       memset(s->used_clusters, 0, sector2cluster(s, s->sector_count));
>
> @@ -2714,7 +2716,7 @@ DLOG(checkpoint());
>        * Use qcow backend. Commit later.
>        */
>   DLOG(fprintf(stderr, "Write to qcow backend: %d + %d\n", (int)sector_num, nb_sectors));
> -    ret = s->qcow->drv->bdrv_write(s->qcow, sector_num, buf, nb_sectors);
> +    ret = bdrv_write(s->qcow, sector_num, buf, nb_sectors);
>       if (ret<  0) {
>   	fprintf(stderr, "Error writing to qcow backend\n");
>   	return ret;

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>