Commit cf5c1a23 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

qcow2: Allocate l2meta dynamically 



As soon as delayed COW is introduced, the l2meta struct is needed even
after completion of the request, so it can't live on the stack.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 593fb83c

block/qcow2.c

+15 −11
Original line number Diff line number Diff line
@@ -774,15 +774,11 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, 
    QEMUIOVector hd_qiov;

    uint64_t bytes_done = 0;

    uint8_t *cluster_data = NULL;

    QCowL2Meta l2meta = {

        .nb_clusters = 0,

    };

    QCowL2Meta *l2meta;



    trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num,

                                 remaining_sectors);



    qemu_co_queue_init(&l2meta.dependent_requests);



    qemu_iovec_init(&hd_qiov, qiov->niov);



    s->cluster_cache_offset = -1; /* disable compressed cache */
@@ -791,6 +787,9 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, 


    while (remaining_sectors != 0) {



        l2meta = g_malloc0(sizeof(*l2meta));

        qemu_co_queue_init(&l2meta->dependent_requests);



        trace_qcow2_writev_start_part(qemu_coroutine_self());

        index_in_cluster = sector_num & (s->cluster_sectors - 1);

        n_end = index_in_cluster + remaining_sectors;
@@ -800,17 +799,17 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, 
        }



        ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,

            index_in_cluster, n_end, &cur_nr_sectors, &l2meta);

            index_in_cluster, n_end, &cur_nr_sectors, l2meta);

        if (ret < 0) {

            goto fail;

        }



        if (l2meta.nb_clusters > 0 &&

        if (l2meta->nb_clusters > 0 &&

            (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)) {

            qcow2_mark_dirty(bs);

        }



        cluster_offset = l2meta.cluster_offset;

        cluster_offset = l2meta->cluster_offset;

        assert((cluster_offset & 511) == 0);



        qemu_iovec_reset(&hd_qiov);
@@ -847,12 +846,14 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, 
            goto fail;

        }



        ret = qcow2_alloc_cluster_link_l2(bs, &l2meta);

        ret = qcow2_alloc_cluster_link_l2(bs, l2meta);

        if (ret < 0) {

            goto fail;

        }



        run_dependent_requests(s, &l2meta);

        run_dependent_requests(s, l2meta);

        g_free(l2meta);

        l2meta = NULL;



        remaining_sectors -= cur_nr_sectors;

        sector_num += cur_nr_sectors;
@@ -862,7 +863,10 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, 
    ret = 0;



fail:

    run_dependent_requests(s, &l2meta);

    if (l2meta != NULL) {

        run_dependent_requests(s, l2meta);

        g_free(l2meta);

    }



    qemu_co_mutex_unlock(&s->lock);