Commit 19dbcbf7 authored by Kevin Wolf's avatar Kevin Wolf
Browse files

qcow2: Fix error handling during metadata preallocation 



People were wondering why qemu-img check failed after they tried to preallocate
a large qcow2 file and ran out of disk space.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 8713f8ff

block/qcow2.c

+9 −6
Original line number Diff line number Diff line
@@ -805,14 +805,14 @@ static int preallocate(BlockDriverState *bs) 
    while (nb_sectors) {

        num = MIN(nb_sectors, INT_MAX >> 9);

        ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);



        if (ret < 0) {

            return -1;

            return ret;

        }



        if (qcow2_alloc_cluster_link_l2(bs, &meta) < 0) {

        ret = qcow2_alloc_cluster_link_l2(bs, &meta);

        if (ret < 0) {

            qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters);

            return -1;

            return ret;

        }



        /* There are no dependent requests, but we need to remove our request
@@ -833,7 +833,10 @@ static int preallocate(BlockDriverState *bs) 
    if (meta.cluster_offset != 0) {

        uint8_t buf[512];

        memset(buf, 0, 512);

        bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1);

        ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1);

        if (ret < 0) {

            return ret;

        }

    }



    return 0;
@@ -1030,7 +1033,7 @@ exit: 
        BlockDriver *drv = bdrv_find_format("qcow2");

        bs = bdrv_new("");

        bdrv_open(bs, filename, BDRV_O_CACHE_WB | BDRV_O_RDWR, drv);

        preallocate(bs);

        ret = preallocate(bs);

        bdrv_close(bs);

    }