Commit 2eaa8f63 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

qcow2: Allow alloc_clusters_noref to return errors 



Currently it would consider blocks for which get_refcount fails used. However,
it's unlikely that get_refcount would succeed for the next cluster, so it's not
really helpful. Return an error instead.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 018faafd

block/qcow2-refcount.c

+15 −3
Original line number Diff line number Diff line
@@ -228,7 +228,10 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index) 
    }



    /* Allocate the refcount block itself and mark it as used */

    uint64_t new_block = alloc_clusters_noref(bs, s->cluster_size);

    int64_t new_block = alloc_clusters_noref(bs, s->cluster_size);

    if (new_block < 0) {

        return new_block;

    }



#ifdef DEBUG_ALLOC2

    fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64
@@ -579,15 +582,20 @@ static int update_cluster_refcount(BlockDriverState *bs, 
static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)

{

    BDRVQcowState *s = bs->opaque;

    int i, nb_clusters;

    int i, nb_clusters, refcount;



    nb_clusters = size_to_clusters(s, size);

retry:

    for(i = 0; i < nb_clusters; i++) {

        int64_t next_cluster_index = s->free_cluster_index++;

        if (get_refcount(bs, next_cluster_index) != 0)

        refcount = get_refcount(bs, next_cluster_index);



        if (refcount < 0) {

            return refcount;

        } else if (refcount != 0) {

            goto retry;

        }

    }

#ifdef DEBUG_ALLOC2

    printf("alloc_clusters: size=%" PRId64 " -> %" PRId64 "\n",

            size,
@@ -603,6 +611,10 @@ int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size) 


    BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC);

    offset = alloc_clusters_noref(bs, size);

    if (offset < 0) {

        return offset;

    }



    ret = update_refcount(bs, offset, size, 1);

    if (ret < 0) {

        return ret;